An implantable cardiac stimulation device, mode switchable between atrial tracking and atrial non-tracking pacing modes includes a threshold control for controlling atrial sensing threshold. The threshold control reduces the sensing threshold from a first threshold used during the atrial tracking pacing mode to a second threshold between the first threshold and the noise for use during the atrial non-tracking pacing mode. The necessity for readjusting the atrial sensing threshold is based upon the ratio of the sensing threshold and atrial amplitudes or upon a diagnostic distribution of atrial amplitudes.

The invention provides an implantable cardiac devices are well known in the art. They may take the form of implantable defibrillators or cardioverters which treat accelerated rhythms of the heart such as fibrillation or implantable pacemakers which maintain the heart rate above a prescribed limit, such as, for example, to treat a bradycardia. Implantable cardiac devices are also known which incorporate both a pacemaker and a defibrillator.
A pacemaker may be considered as a pacing system. The pacing system is comprised of two major components. One component is a pulse generator which generates the pacing stimulation pulses and includes the electronic circuitry and the power cell or battery. The other component is the lead, or leads, which electrically couple the pacemaker to the heart.
Pacemakers deliver pacing pulses to the heart to cause the stimulated heart chamber to contract when the patient's own intrinsic rhythm fails. To this end, pacemakers include sensing circuits that sense cardiac activity for the detection of intrinsic cardiac events such as intrinsic atrial events (P waves) and intrinsic ventricular events (R waves). By monitoring such P waves and/or R waves, the pacemaker circuits are able to determine the intrinsic rhythm of the heart and provide stimulation pacing pulses that force atrial and/or ventricular depolarizations at appropriate times in the cardiac cycle when required to help stabilize the electrical rhythm of the heart.
Pacemakers are described as single-chamber or dual-chamber systems. A single-chamber system stimulates and senses the same chamber of the heart (atrium or ventricle). A dual-chamber system stimulates and/or senses in both chambers of the heart (atrium and ventricle). Dual-chamber systems may typically be programmed to operate in either a dual-chamber mode or a single-chamber mode.
A popular mode of operation for dual-chamber pacemakers is the DDD mode. Specifically, DDD systems provide atrial pacing during atrial bradycardia, ventricle pacing during ventricular bradycardia, and atrial and ventricular pacing during combined atrial and ventricular bradycardia or heart block also known as AV block. In addition, DDD systems provide an atrial synchronous (atrial tracking) mode. This enables ventricular activity to track atrial activity to more closely approximate the normal response to exercise, or other physiological activity demanding a faster heart rate, by permitting a rate increase to occur commensurate with the rate of the sensed P waves. This advantageously increases cardiac output and facilitates maintenance of AV synchrony.
Atrial fibrillation is a common atrial tachyarrhythmia. Although it is not life threatening, it is associated with strokes thought to be caused by blood clots forming in areas of stagnant blood flow as a result of prolonged atrial fibrillation. Symptoms of atrial fibrillation may include heart palpitations and dizziness.
Atrial fibrillation can occur suddenly. It results in rapid and chaotic activity of the atria of the heart. The chaotic atrial activity in turn causes the ventricular activity to become rapid and variable. It is an extreme environment in which to properly pace the heart in a tracking mode. Hence, it is particularly important for pacemakers to include mode switching for switching from an atrial tracking mode to an atrial non-tracking mode.
Automatic mode switching (AMS) is intended to limit excessive pacing in the ventricles, due to atrial tachycardia or fibrillation, by switching from an atrial tracking pacing mode to an atrial non-tracking pacing mode. During AMS, the system will pace at a constant rate in the ventricles if it is not inhibited by an intrinsic ventricular sensed event. AMS addresses the problem of potential excessive ventricular pacing at some cost. At the time of a mode switch, the ventricular pacing rate drops to the programmed AMS rate, which is often much lower than the current pacing rate. During an episode of atrial fibrillation, the electrical signals from the atria often become small and highly variable, increasing the incidence of inappropriate sensing with the fixed atrial sensitivity setting previously determined during normal sinus rhythm. Due to the inappropriate atrial sensing, the pacing system can easily fall in and out of the atrial non-tracking mode and atrial-tracking mode. This is a mode switch oscillation. The result is that the patient is alternately paced at higher ventricular rates when the system is out of the atrial non-tracking mode and at a much lower ventricular rate when it is in the non-tracking mode. This increases patient morbidity.
The present invention eliminates mode switch oscillation due to inappropriate sensing. By automatic adjustment of atrial sensitivity to appropriate levels during mode switch, mode switch oscillation is avoided. This reduces the discomfort of patients and improves their quality of life.

Implantable cardiac device providing mode switching and automatic atrial sensitivity control and method


Stability enhancement agents for use in a solidification matrices and solid detergent compositions are described. Stability enhancement is provided by a hydratable salt, water and phosphinosuccinic acid (PSO) derivative binding agents forming a dimensionally stable composition. Preferred phosphinosuccinic acid (PSO) derivatives include phosphinosuccinic acid and mono-, bis- and oligomeric phosphinosuccinic acid (PSO) derivatives. The stability enhancement composition for use in a solid detergent and solid detergent compositions are preferably biodegradable and substantially free of phosphate and NTA-free.

The use of solidification technology and solid block detergents in institutional and industrial operations was pioneered in the SOLID POWER® brand technology claimed in Fernholz et al., U.S. Reissue Pat. Nos. 32,762 and 32,818. Additionally, sodium carbonate hydrate cast solid products using substantially hydrated sodium carbonate materials was disclosed in Heile et al., U.S. Pat. Nos. 4,595,520 and 4,680,134. In more recent years, attention has been directed to producing highly effective detergent materials from less caustic materials such as soda ash, also known as sodium carbonate. Early work in developing the sodium carbonate based detergents found that sodium carbonate hydrate-based materials often swelled, (i.e., were dimensionally unstable) after solidification. Such swelling can interfere with packaging, dispensing, and use. The dimensional instability of the solid materials relates to the unstable nature of various hydrate forms prepared in manufacturing the sodium carbonate solid materials. Early products made with hydrated sodium carbonate typically comprised of anhydrous, a one mole hydrate, a seven mole hydrate, a ten mole hydrate or more mixtures thereof.
However, after the product had been manufactured and stored at ambient temperatures, the hydration state of the initial product was found to shift between hydrate forms, e.g., one, seven, and ten mole hydrates, resulting in dimensional instability of the block chemicals. In these conventional solid form compositions, changes in water content and temperature lead to structural and dimensional change, which may lead to a failure of the solid form, resulting in problems such as the inability of the solid form to fit into dispensers for use.
Additionally, conventional solid alkaline detergents, particularly those intended for institutional and commercial use, generally require phosphates in their compositions. The phosphates typically serve multiple purposes in the compositions, for example, to control the rate of solidification, to remove and suspend soils, and as an effective hardness sequestrant. An exemplary phosphate having broad spectrum functionality is sodium tripolyphosphate (STPP), providing beneficial effects as a threshold agent, providing metal protection, soil antiredeposition, etc.
It was found, disclosed, and claimed in U.S. Pat. Nos. 6,258,765, 6,156,715, 6,150,324, and 6,177,392, that a solid block functional material could be made using a binding agent that includes a carbonate salt, an organic acetate, such as an aminocarboxylate, or phosphonate component and water. Due to ecological concerns, further work has recently been directed to replacing phosphorous-containing and/or phosphate-containing compounds in detergents. In addition, nitrilotriacetic acid (NTA)-containing aminocarboxylate components used in place of phosphorous-containing and/or phosphate-containing compounds in some instances as a binding agents and hardness sequestrants, are believed to be carcinogenic. As such, their use has also been curtailed. In addition, the expense of various phosphate-replacement components, such as polyacrylates, provides an indication for a more cost-effective replacement solidification matrix.
Accordingly, it is an objective of the claimed invention to identify binding agents capable of providing exceptional dimensional stability for a solid detergent composition.
Still further, an object of the invention is to develop such dimensionally stable, solid detergent composition that may be, substantially free of phosphate and free of NTA.
A still further object of the invention is to employ mono-, bis- and oligomeric phosphinosuccinic acid (PSO) derivatives for a solidification matrix which provides efficient detergency from the solid detergent compositions of the invention, without causing significant hard water scale accumulation.

Solidification matrix comprising phosphinosuccinic acid derivatives


One embodiment of the fabric (10) of the present invention includes an upper portion (12), middle portion (20) and lower portion (14), with the upper portion (12) having raised surface construction hydrophobic first yarns (16), the lower portion having hydrophilic (18) second yarns and the middle portion (20) being a region in which ground yarns (22), hydrophobic first yarns (16) and hydrophilic second yarns (18) are integrated. The upper portion (12) further includes at least one channel (24), which is a region free of raised surface construction hydrophobic first yarns (16). The channel (24) facilitates transmission of fluid from the fabric upper portion (12) to the lower portion (14) by exposing a part of the lower portion hydrophilic second yarns (18) which extends into the middle portion (20) directly to fluid on the upper portion (12), thereby enabling the fluid to contact and be absorbed by a hydrophilic second yarn (18) without first having to wick along a raised surface construction hydrophobic first yarn (16). In a preferred embodiment, several adjacent channels (24) are aligned to form elongated channels (24) which intersect one another in a grid-like fashion. The fabric may be incorporated into undergarments, suitable examples of which include an infant T-shirt (52), a woman's panty (62) and a man's brief (70).

This invention relates to absorbent fabrics for managing bodily fluids and, more particularly, to absorbent fabrics which include hydrophobic yarns and which are reusable after washing. The invention also relates to washable and reusable undergarments which incorporate such absorbent fabrics.
The use of absorbent fabrics for managing bodily fluids is known. For example, several fabrics have been introduced which include multiple fabric layers, such as a body-facing hydrophobic layer or layers in combination with a garment-facing hydrophilic layer or layers, so as to wick moisture away from the body. These multiple layers are typically held together by stitching or adhesive. Unfortunately, the traditional multilayer fabrics tend to be quite thick, which makes them bulky and uncomfortable when incorporated into undergarments. Furthermore, this bulkiness makes such undergarments more noticeable underneath outer garments such as a dress or pair of pants.
More recently, absorbent fabrics have been introduced which incorporate the beneficial properties of hydrophobic and hydrophilic layers, without the thickness, bulk and discomfort of previous absorbent fabrics. These more recently developed fabrics are integrally knit fabrics having an uppermost top portion and a lower or bottom portion held together with an intermediate or middle portion. The top portion is a set of hydrophobic yarns having a raised surface construction, for example, loop pile, while the bottom portion includes a set of hydrophilic yarns, also usually having a raised surface construction. The middle portion includes one or more sets of ground yarns, which may be any yarns suitable for integrating the yarns of the top and bottom portions, as well as an inner portion of the hydrophobic and hydrophilic yarns themselves. One such fabric is shown in Heiman U.S. Pat. No. 5,290,269, and is available under the trademark COMPLY.RTM. from Standard Textile Co., Inc., located in Cincinnati, Ohio.
In addition to being relatively thin, such integrally knit fabrics also are able to absorb and retain significant amounts of fluid. When used to manage bodily fluids, the upper hydrophobic portion is placed against the body. Any fluids discharged by the wearer contact the raised hydrophobic yarns of the top portion, wick "down" the raised hydrophobic yarns toward the middle portion, where the fluid contacts and is absorbed by hydrophilic yarns in the middle portion, and pass into the bottom portion where the fluids are retained. Furthermore, due to the nature of the raised hydrophobic yarns and the generally close spacing of the yarns, fluid which has migrated into the bottom portion generally does not move back across the fabric to the upper surface of the top portion hydrophobic yarns, thereby providing a dry and comfortable feel to the wearer.
However, when such integrally knit fabrics receive a fluid discharge, droplets of fluid may remain on the body-facing surface of the top portion for a period of time before being wicked toward the hydrophilic yarns of the bottom portion, thereby extending the time it takes to move fluid away from the user's body, and making the wearer uncomfortable.

Absorbent fabric and undergarments incorporating the fabric


A power transmitting apparatus can comprise a clutch housing, a plurality of driving clutch plates, a plurality of driven clutch plates movable for carrying out the pressure-contact or release relative to the driving clutch plates, a clutch member, a pressure member, pressure-contact assisting cam, back-torque limiting cam characterized in that one set of cam surfaces of the pressure-contact assisting cam or the back-torque limiting cam are arranged so that they extend along a circumferential edge of the clutch member. A crowning can be formed on one set of cam surfaces in their extending direction and/or their width direction.

1. Field of the Inventions
The present inventions relate to power transmitting apparatuses for arbitrarily transmitting or cutting-off a rotational force of the input member to or from the output member.
2. Description of the Related Art
In general, power transmission apparatuses for motorcycles are intended to arbitrarily transmit or cut-off a power of an engine to a transmission and a driving wheel. Such power transmission apparatuses typically comprise an input member connected to an engine side, an output member connected to the transmission and the driving wheel side, and a clutch member connected to the output member. The power can be transmitted by pressing together a plurality of driving clutch plates and driven clutch plates and cut-off by releasing the pressure force between the plates.
For example as disclosed in Japanese Laid-open Patent Publication No. 150517/1990, cams are provided for increasing the pressure-contacting force between the driving and driven clutch plates during an ordinary power transmitting phase and the other function, i.e. back-torque limiting function for releasing the driving and driven clutch plates when the rotational speed of an output member has exceeded the rotational speed of an input member. In such a power transmitting apparatus, the cams are formed by gradient surfaces (cam surfaces) formed on the pressure plate and the clutch member.
According to the power transmitting apparatus of this prior art, one set of cam surfaces (pressure-contact assisting cam surfaces) act in an ordinary power transmitting mode to move a pressure plate toward a direction in which both the driving and driven clutch plates are strongly pressed to each other, and on the contrary, in a back-torque absorbing mode the other set of cam surfaces (back-torque limiting cam surfaces) act to move the pressure plate toward a direction in which the pressure-contact between the driving and driven clutch plates are released.


A chemical storage facility, dispensing area, or equivalent unit is provided with a safety interlock device which automatically regulates access to the inlet used to introduce materials into the unit responsive to markings provided on the containers which hold such materials. In connection with the handling of potentially hazardous chemicals, such regulation is performed responsive to information provided on labeling associated with the bottles which contain the chemicals to be used. A bar code scanner is used to read bar-coded information provided on the labels affixed to the bottles, and the access door of the chemical storage facility or dispensing area is released, allowing the door to be opened, only in cases where the bar-coded information read by the scanner is found to correspond with the proper chemical to be dispensed. If the bar-coded information read by the scanner is found to correspond with some other (incorrect) chemical, the access door remains locked to prevent the incorrect chemical from being dispensed.

In any of a variety of applications, it is important for materials to be dispensed in correct type, in proper combination, in proper order, etc., to ensure that a proper result is achieved. As an example, and in the context of chemical storage and dispensing, it is often important for a chemical or a group of chemicals used in a particular process to be dispensed in regulated fashion. This can include assurances that a correct type of chemical is dispensed, that a desired combination of chemicals is dispensed, possibly in a particular order, that a particular chemical or combination of chemicals is not dispensed, or to ensure or protect against any of a number of possible variations associated with a particular chemical processing operation.
While similar problems are found in any of a number of applications, the improvements of the present invention are primarily directed to the loading of chemicals into a desired processing unit. In this context, it is common practice to introduce a chemical (or different chemicals) into the processing unit through an access port or door which is sized and configured to receive the container (e.g., a vessel or bottle) which holds the chemical to be dispensed. When it becomes appropriate to dispense a particular chemical (or chemicals), the container is introduced into the processing unit, through the door, for the discharge of its contents. In many instances, the container will be pressurized to facilitate in the discharge of its contents.Recognizing the need to carefully control such chemical dispensing, steps have been taken to develop systems for regulating the processes which are used to dispense such materials. Various types of labeling have been used to better inform the handler of such materials of the particular identity, use, and any contra-indications which may be pertinent to such materials. This can include any of a number of special markings or color coding for prompting or warning against a particular use or combination. However, irrespective of the labeling which is used, such markings remain subject to being misread, or other human error.
For this reason, attempts have been made to automate such regulation of the dispensing process to provide further assurances of a correct, and safe result. As an example, the bottles for containing the materials to be dispensed have been provided with special shapes and/or sizes for "keying" such vessels to the dispensing apparatus with which the materials they contain are to be used. This can include variations in the size and/or shape of the bottle itself, or more commonly, special sizing and/or shaping of the neck, spout, etc., associated with the bottle. By correspondingly sizing and/or shaping the inlet or port for accessing the processing unit, the dispensing of materials can be automatically limited to those materials which are contained in the corresponding vessel, achieving an appropriate level of assurance.
However, such keying requires the use of special vessels, and special ports for receiving such vessels, which can limit the overall use of such systems. This also fails to effectively accommodate applications which call for changing operating conditions or requirements, or combinations of processes, conditions or requirements which require careful control. As an example, let it be assumed that in a particular process, either of two different chemicals need to be introduced at a given point, but that introduction of the wrong chemical at the wrong time, or in the wrong order, will lead to a hazardous condition. Keying each of the vessels containing the two different chemicals to the intended (same) access port would provide no assurances that the chemicals are introduced at the correct time or in the desired order. The use of different keys, to ensure that the two different chemicals are correctly dispensed, would then prevent both of the vessels from being introduced through the same (keyed) port. Other systems attempted for similar purposes have in practice been found to be similarly limited.

Safety interlock for use in handling hazardous materials


The aim of the invention is to design a bulk-material cooler, particularly one for cooling cement clinker, which operates according to the walking floor principle, so that its cooling grate can be composed of a multitude of ventilated cooling grate modules, which can be assembled in an easy and variable manner, in order to obtain large lengths and widths of the cooler. When these cooling grate modules move between an advancing and returning position, even lateral and/or height offset of the guiding elements can be compensated for in a kinematic manner. To this end, the invention provides that the cooling grate, when viewed over the length and width of the cooler, is composed of a multitude of modules (13, 14) ventilated with cooling air. The coupling of the cooling grate modules of each longitudinal row of cooling grate modules is effected by an articulated joint.

The invention relates to a bulk material cooler having a cooling grate which carries the material to be cooled, such as hot cement clinker, and which conveys the material to be cooled from the material charging end to the material discharging end while a flow of cooling gas flows through said material to be cooled.
Grate coolers are used in the non-metallic minerals industry in order to drastically cool the material, such as cement clinker or other minerals, previously fired in a kiln, immediately afterwards on the cooling grate. For conveying the hot material to be cooled over the cooling line, the use of reciprocating grate coolers is particularly common, the grate system of which coolers comprises multiple alternately fixed and moving grate plate carriers, on each of which multiple grate plates are fixed, which are provided with cooling air apertures and which have a basically upward flow of cooling air passing through them. At the same time, viewed in the conveying direction, rows of fixed grate plates alternate with rows of reciprocating grate plates, which by way of their correspondingly reciprocating grate plate carriers are fixed to one or more driven reciprocating frames supported so that they can move longitudinally. The hot material to be cooled is gradually conveyed by the common oscillating movement of all moving rows of grate plates and is cooled in the process.
As an alternative to the aforementioned conventional reciprocating grate cooler, EP-1 021 692 B1 discloses a type of grate cooler in which the cooling grate with a flow of cooling air passing through it is not moved but is fixed, multiple rows of adjacent, reciprocating bar-shaped reciprocating elements being arranged above the fixed grate surface transversely to the conveying direction of the material to be cooled, said elements being moved between a forward stroke position in the material conveying direction and a return stroke position, so that the material is progressively moved from the beginning of the cooler to the end of the cooler by the reciprocating movement of these reciprocating elements in the bed of material to be cooled, cooling the material in the process. In a similar known type of grater cooler disclosed by DE 100 18 142 A1 the reciprocating elements moving above the fixed cooling grate base are divided into at least two groups and the reciprocating elements are moved forwards together in the conveying direction, but are moved backwards separately from one another rather than together.
In these known types of grate coolers the conveying capacity is decisively influenced by the difference between the volume of cement clinker moved by each forward stroke in the conveying direction and the volume of clinker undesirably moved counter to the conveying direction by the return stroke movement. In addition, in these known types of grate cooler the cross bar-shaped reciprocating elements are fixed on top of vertical drive plates oriented in the longitudinal direction of the cooler, which extend through corresponding longitudinal slots in the cooling grate and are driven from beneath the cooling grate, making it relatively expensive to seal off the cooling grate, charged with material to be cooled, to prevent material falling through the drive plate apertures, and thereby to keep the material wear within bounds. The reciprocating elements moved in the hot cement clinker bed are exposed to a high level of thermal and mechanical wear, reducing the service life of the grate cooler. Finally the hot bed of bulk material is intermixed by the reciprocating elements moved in the bed of material, which has a detrimental effect on the thermal efficiency of such types of grate cooler.
In addition, DE 196 51 741 A1 discloses a cooling tunnel for cooling and/or freezing material to be cooled by means of cold air, using a so-called "walking floor" conveying principle, in which multiple adjacent floor elements of the cooling tunnel are moved forwards together in the conveying direction but are moved back separately from one another rather than together. The intention is to form a high bulk material bed over the floor elements, which fills the entire cooling tunnel cross section, so that the cooling gas flows through the progressively advancing bulk material in the opposite direction. The actual floor elements remain uncooled by the cooling gas, so that the known cooling tunnel would be unsuited to cooling red hot cement clinker falling from the discharge end of a rotary kiln. The direct contact of the hot cement clinker with the surface of the floor elements would mean exposure to a high level of thermal and mechanical wear and in the case of hot cement clinker would therefore lead to an inadequate service life of such a cooling tunnel. Furthermore, the adjacent floor elements of such a cooler could not be used with a long length of 40 to 50 m, for example, such as industrial grate coolers need in terms of their throughput capacities and cooling line lengths for the cooling of hot cement clinker.

Bulk-material cooler for cooling hot material to be cooled


A method and apparatus for content coding of Audio-Visual materials is presented. The content coding can then be decoded by a home station where the content coding is collected and processed. The content codes are utilized by the subscribers home station to collect information on the subscribers selection of AVM streams and record information on which AVMs have been presented to the subscriber. An audio-video material distribution system is described for supplying AVM streams to home station via a local distribution network. The home stations decode the content coding from the AVM streams and collect the encoded content codes. The collected content codes are then sent to collection centers for processing. The encoded information may also utilized to provide management of an upstream channel between the home stations and the video distribution node.

RELATED APPLICATIONS
The present invention relates to "A METHOD AND APPARATUS FOR SCREENING AUDIO-VISUAL MATERIALS PRESENTED TO A SUBSCRIBER" Ser. No.: 08/568,166 filed Dec. 6, 1995 assigned to the same assignee as the present invention, herein incorporated by reference.
1. Field of the Invention
The present invention relates to a method and apparatus for collecting and recovering subscriber behavior from a plurality of home stations in a broadcast and/or interactive service distributing audio-visual materials. More particularly, it relates to a method and apparatus involving, a universal audio-visual identification code embedded in audio-visual materials, a software system residing in the home station to monitor and record the viewing of these audio-visual materials and returning the collected data to a behavior collection center for interpretation, accumulation and processing.
2. Description of the Prior Art
Broadcast and/or Interactive television may be distributed over a variety of means, including but not limited to coaxial-analog or digital and fiber-coax cable systems, ADSL (Asymmetrical Digital Subscriber Loop), wireless and satellite distribution systems. In most cases, interactive television will co-exist with broadcast television in both its current analog form and, in the future, in its digital form.
Broadcast television is currently distributed over the air, satellite systems and over Community Access Television (CATV) systems. Most systems are designed for two-way transmission, only requiring the installation of upstream amplifiers and upstream transmitters in set-top terminals in the home to complete the two-way loop. Certain services such as impulse Pay-Per-View, where a subscriber may purchase a movie on impulse by simply ordering it through the set-top terminal, already make use of the upstream capabilities of a TV broadcast system. The upstream-channel is not unique to analog TV. Other digital broadcast systems such as an HDTV over digital cable transmission, ADSL and wireless will also have the capability to transmit data from the subscriber set-top terminal to a central control location.
Television marketing has not enjoyed the technological tools available to consumer goods marketers. Data supplied by rating agencies such as the Nielsen or Arbitron are limited to very small samples of the U.S. television viewing market. This is in part due to the difficulty of compiling data on every television viewer. Although surveys have been considered to be adequate as decision aids for show productions, they have not allowed for the customization of programming on a smaller sample, as in neighborhoods or on a per viewer basis.
Interactive television promises viewers the ability to view what they want, when they want. However, as any marketing person can profess, the consumer usually does not know what he or she wants until they are informed of their choices. Since there will be a plethora of choices offered by Interactive TV (ITV) viewers, accurate targeting of interactive television content is as valuable as in its parallel in the consumer goods market.
In addition to the marketing of interactive services, user viewing information is also useful for targeted advertising. Advertisements can be customized on a per area or even per viewer basis to increase their effectiveness. Without accurate targeting, a movie, game, advertisement, or in general, any interactive service, will be lost in the multitude of choices. In summary, proper targeting of interactive services and advertisements will become an essential part of marketing interactive services and making the most of the installed infrastructure.
Advertising rates for commercials for TV programs are determined by the expected size of the viewer audience for a predetermined number of television programs. These expectations are usually determined the estimated audience sizes of previously broadcast shows. For example, a weekly television series, the estimate of audience size for upcoming episodes is based on the estimated size of previously broadcast shows. In addition advertising rates may be adjusted based on an "after the fact" estimation of the market share for the televised program.
Present systems for estimating market share involve survey evidence such as the Nielsen ratings. Previous market data was taken by selecting households to record their viewing habits. For example, a selected household might record in a written journal or diary when the television is turned on and turned off, what channels are selected and the number of viewers in the room. This data may alternatively be collected by providing the user with an electronic device having a button that indicates turning on or off the television and the channel selected. Other systems are connected directly to the television that will monitor power on and off and the channel and time of the selected programs. The system is wired to a dedicated telephone line. When instructed, the electronics dump their memory over the phone line to a central computer for analysis. Each of these systems requires selecting individual households that represent an adequate sample of the general viewing audience and requires physically setting up the monitoring apparatus. These systems are inaccurate because the sample size is small, diary entries may be erroneous, or require viewer action.
Collecting subscriber behavior in a set-top can be provided by collecting user channel transitions. However, such statistics do not provide for the collection of any information about the viewed material itself. Since the viewed material may be received through a variety of channels controlled by more than one source (for example some signals may be generated by the cable-tv company while others may be produced by local stations), simply recording channel transitions and relaying them to a central processing point will not be sufficient to collect accurate viewing statistics.
Consequently, there remains a need for a method to universally identify audio-visual material broadcast through ITV (analog or digital) systems and to record these in an efficient manner to produce viewing statistics.

Method and apparatus for monitoring audio-visual materials presented to a subscriber

International Business Machines Corporation


A multipurpose, flexible cover for medical instruments with a closed-end cover that is optically clear throughout. The transparent cover is used with optical medical instruments such as cameras and lasers. The cover has a closed end that is a homogeneous polyurethane piece folded over itself and sealed along its side edges to form a receptacle to retain the medical instrument. The closed-end portion, which can be associated with a different types of cameras and lasers, is optically clear with surgical clarity.

The invention generally relates to covers for medical instruments requiring optical transparency. Specifically, the invention entails a multipurpose, closed-end cover that is optically clear with surgical clarity throughout the closed end.
With the wide use of medical instruments that must remain sterile and require unobstructed optical clarity, the present cover provides a means for maintaining sterility and not inhibiting the scene. Use is compatible with different types of cameras, laser equipment, and other optically related instruments. This invention does not require the use of a lens or a special fenestration in the cover for viewing or functioning through.
A large variety of scopes have been developed to serve a physician's different needs during endoscopic surgeries. A surgeon may use several different scopes during one operation. Changing the sterile scope that had been attached to a non-sterile instrument such as a camera will compromise the sterility of the scope and therefore possibly the entire procedure. Others in the industry have provided covers for medical instruments used in endoscopic examinations that allows switching among similar instruments. A closed-end covering, which is embodied in U.S. Pat. No. 4,522,196, was developed that provides a permanent, semi-rigid, optically clear fenestration between the scope eyepiece and the camera lens. The use of a lens requires an extra seal around the lens and a means for implanting that lens into the plastic covering.
U.S. Pat. No. 4,522,196 is directed to a reusable, sterile covering for a surgical camera. The flexible covering is for use in combination with an endoscope and a camera that has a lens-to-endoscope coupling. The coupling temporarily couples the endoscope to the camera. The covering comprises a body portion for covering the camera and an end portion for enclosing the coupling and for defining a barrier by interposition between the camera and endoscope. The end portion is optically clear and made of material that is a rigid or semi-rigid relative to the flexible covering material. The clear end portion fits in the optical path between the endoscope and the camera. This covering is used for the same purpose as the present video camera sterilization embodiment, however, the '196 patent's covering in each embodiment is in combination with an optically clear aperture or member registered in the endoscope-to-camera optical path. In all embodiments, the '196 patent requires that the covering have a clear aperture portion or separate member attached to it or the covering is sealed around the clear portion. The '196 patent does not suggest or teach that the material used for the clear portion would comprise the entire sterile cover or that such a material exists that would be useful for replacement of the covering. It merely suggests that for the aperture, or separate member, that is to be registered in the optical path, a clear plastic film could be used at this portion. The video camera sterilization device of the present invention does not require a means for registering an optically clear aperture or member.
The semi-rigid fenestration of optically clear plastic must be correctly lined up with the eyepiece of the scope and the lens of the video camera for the image to be centered and completely and/or clearly shown on the monitor. The variety of camera sizes may make the fenestration size important for switching among instruments. The plastic film that is attached to the fenestration is somewhat stiff and not transparent. The alignment can be awkward, especially where sterile instruments are initially inserted into the cover during or for a sterile operative procedure.
The previous utilization of a lens or an optical portion construction can preclude clear viewing through the cover if the instrument moves inside the cover. Further, the seal around the lens increases the chance of leakage or other failure. No discovered prior art discloses a single-material, transparent polyurethane closed-end cover portion for a laser or a camera and camera lens coupled to an endoscope. The present application eliminates the separate and/or different material end portion of the cover and uses only a homogenous flexible optically clear, non-static polyurethane to cover the laser or camera lens and the rest of the camera body. The optical clarity can be distorted only by a very narrow seam if the camera or laser is not inserted in the center part of the cover. The cover must be misaligned at least 90.degree. for the seam to affect the image. The foregoing needs also exist in the medical field for other procedures.
Accordingly, it would be desirable to provide a totally clear closed-end cover, which is distortion free for surgical clarity, that can be used to maintain sterility of medical equipment. The present invention has an optically clear closed-end. Any portion of the polyurethane closed-end portion is sufficiently clear for optical use and there is no need to position a lens over the video camera. Moreover, it would be significant in the medical industry to provide a cover that is distortion free to allow accurate viewing of procedures being filmed.
In connection with the foregoing objectives, the chosen polyurethene material is optically clear so that one can see through any portion of the polyurethane closed-end portion with surgical acuity. There is no need to position a lens or specifically formed fenestration over a video camera or laser. Therefore, there is no need for a circular lens to fit over the lens of the camera itself, which abuts the eyepiece of the endoscope. Also, the optically clear, polyurethane, closed-end cover eliminates (1) the need to have a cover with a seal around an attached lens held in the cover, (2) means for implanting the lens in the plastic cover, and (3) the need for means to position a lens in the optical path between scope and camera.
It is a further goal of the invention to provide a cover where the closed-end portion applied to the medical instrument is compatible with lasers. Optical clarity improves the performance of a laser.
It is also a goal of the invention to provide a cover that conforms easily to different camera configurations. The present invention functions with direct in-line scope attachments and with scopes where the camera couplers are perpendicular to the camera. The camera couplers with the scope attached perpendicular to the camera can be used with the present device without concerns of aligning the cover or inserting a new cover because the present closed-end portion is optically clear.
Further, it is another intention of the invention to provide a cover that is supple, pleasant to touch, and durable. The specifications of the preferred components provides these attributes. Other aspects and benefits of the invention will be appreciated by those practicing medicine in each respective additional application of the cover.

Optically transparent medical instrument cover


A rotary piston compressor comprises a cylinder block (100), an eccentric rotor group (200) being fitted in the chamber of the cylinder block, a shaft (2) and a separating means (40). The eccentric rotor group (200) comprises a cylindrical rotor (4) provided on the shaft (2) and rotatable therewith, and a collar (3) rotationally provided on the cylindrical rotor (4). The separating means (40) is used for separating the axially extended sealed chamber, which is formed between the outer peripheral surface of the eccentric rotor group (200) and the inner wall of the cylinder block (100), into an induction chamber (70) and an exhaustion chamber (71). Wherein, the separating means (40) comprises: a baffle (8) provided between the inner wall of the cylinder block (100) and the collar (3) provided on the outer periphery of the eccentric rotor (4), a contact member (7) provided between the baffle (8) and the collar (3) and contacted therewith, and a jointing element (6) connecting the contact member (7) to the baffle (8) and the collar (3) respectively.

Conventional rotor compressors have significant advantages compared to other types of compressors, but they have the following drawbacks: the manufacturing process is complicated, the sealing is not reliable, and the reliability of the mechanical structure and the sealing drops significantly especially when the volume increases, and as a result, it is difficult to increase flow volume. The main reason that results in the above drawbacks lies in that the movable separating block, which separates the high pressure chamber from the low pressure chamber, has a small moving range and has a poor reliability. And when increasing the flow volume, the manufacturing process is more difficult to realize.


The present invention provides a processing aid for thermoplastic resin having a weight average molecular weight of 10,000 to 300,000, which is obtained by polymerizing an alkyl (meth)acrylate, or an alkyl (meth)acrylate and another vinyl monomer copolymerizable therewith, in the presence of a mercaptan having an alkyl ester group with C4-20 alkyl group as a chain transfer agent, and/or an organic peroxide having a tertiary-butyl peroxy group as a polymerization initiator.

Thermoplastic resins, such as vinylchloride resins, polyethylene, polypropylene, polyester, polystyrene, polycarbonate, a methacrylate resin, and ABS resin, are excellent in physical properties, and have economic advantage and applicability, and have been widely used in various fields. However, since these resins have high melt viscosity and low fluidity, and are susceptible to thermal decomposition, there are problems in processability that they have a narrow processable condition in molding, and that they tend to stick or adhere to a metal surface of a device in processing at a high temperature.
Now there have been proposed many techniques in order to solve the above-mentioned problems in processability.
Applicability of vinylchloride resins, polyethylene, polypropylene, polyester, polystyrene, polycarbonate, a methacrylate resin, ABS resin and the like can be improved by physically blending modifiers such as a lubricant, a stabilizer, a colorant, a filler, a pigment, a cross-linking agent, a tackifier, a plasticizer, a processing aid, an impact modifier and a modifier for thermal deformation temperature, before processing.
Moreover, in order to improve molding processability at molding of vinylchloride resins, polyethylene, polypropylene, polyester, polystyrene, polycarbonate, a methacrylate resin, and ABS resin, some of copolymers compatible with those resins have been investigated as a processing aid.
For example, there have been proposed a method in which a copolymer of methyl methacrylate and styrene is added to vinylchloride resins (Japanese Examined Patent Publication No. 32-4140 (1957)), a method in which a copolymer of styrene and acrylonitrile is added thereto (Japanese Examined Patent Publication No. 29-5246 (1954)), a method in which a copolymer mainly containing methyl methacrylate is added thereto (Japanese Examined Patent Publication No. 40-5311 (1965)), a method in which a copolymer of styrene and alkyl acrylate is added thereto (Japanese Examined Patent Publication No. 37-1384 (1962)) and the like. Secondary processability such as an increase in melting rate of vinyl chloride resins and an increase in tensile elongation at a high temperature can be improved, but there is no effect in reducing adhesiveness to a metal face of the molding device.
Thereafter, in order to reduce adhesiveness to a metal surface of a molding device, there has been investigated a method in which a copolymer of styrene, an alkyl (meth)acrylate and (meth)acrylate having an oxygen atom in addition to an ester bond is added to vinyl chloride resins (Japanese Examined Patent Publication No. 58-56536 (1983)). In this method the adhesiveness is proved to be improved, but this method cannot always satisfy the demands in the market.

Processing aid for thermoplastic resin and thermoplastic resin composition containing the same


A probe for use with a measurement instrument includes a circuit connected to the probe. The probe comprises a process adaptor for mounting to a process vessel and including a through bore extending from a connector end to a process end. A counterbore at the connector end defines a shoulder. A support assembly is received in the counterbore and rests on the shoulder. The support assembly comprises an annular rod support having a through opening with a tension rod extending through the opening and secured at opposite sides of the annular rod support. A locking nut secures the support assembly in the counterbore to maintain the annular rod support in compression. A probe rod extends from a process end of the tension rod. A seal assembly is operatively secured to the process adaptor at the connector end with the seal pin in electrical contact with a connector end of the tension rod.

Process control systems require the accurate measurement of process variables. Typically, a primary element senses the value of a process variable and a transmitter develops an output having a value that varies as a function of the process variable. For example, a level transmitter includes a primary element for sensing level and a circuit for developing an electrical signal proportional to sensed level.
Knowledge of level in industrial process tanks or vessels has long been required for safe and cost-effective operation of plants. Many technologies exist for making level measurements. These include buoyancy, capacitance, ultrasonic and microwave radar, to name a few. Recent advances in micropower impulse radar (MIR), also known as ultra-wideband (UWB) radar, in conjunction with advances in equivalent time sampling (ETS), permit development of low power and low cost time domain reflectometry (TDR) instruments.
In a TDR instrument, a very fast pulse with a rise time of 500 picoseconds, or less, is propagated down a probe, that serves as a transmission line, in a vessel. The pulse is reflected by a discontinuity caused by a transition between two media. For level measurement, that transition is typically where the air and the material to be measured meet. These instruments are also known as guided wave radar (GWR) measurement instruments.
In one form, a guided wave radar (GWR) transmitter uses a coaxial probe that functions as an electrical transmission line into the process vessel. The GWR measurement process begins with an electrical pulse that is launched along the probe from one end. A TDR circuit identifies impedance discontinuities along the length of the probe. One source of an impedance discontinuity occurs at the vapor to liquid interface due to the difference in the relative dielectrics of the media. The TDR circuit detects, and locates in time, the reflected signal from the interface. Another source of an impedance discontinuity can be a change in geometry in the transmission line. This is a convenient method for producing a known reference location, called a fiducial (FID) in the probe. The difference in the TDR time measurements of the fiducial to the vapor to liquid interface is used to calculate the liquid level. Another impedance discontinuity exists at the end of the probe (EOP). With this type of probe and TDR circuit an increased impedance creates a positive reflected signal.
In high pressure and high temperature applications, the probe may include a small glass or ceramic seal. The seal has a small pin of approximately 1 mm diameter as an inner conductor. The pin is not capable of supporting a probe rod. Therefore, the probe rod must be supported by other structure using electrical insulating materials to function as a transmission line.
Known probes use a flexible coupling system to take up deflection due to loads on the probe rod to reduce stresses in the seal. Known flexible coupling systems require disk springs, ceramic disks, and a collar on a probe rod which is clamped between the ceramic disks. A disadvantage of ceramic materials is that they are typically brittle and have relatively low tensile strength.
The present invention is directed to solving one or more of the problems discussed above in a novel and simple manner.


A memory and a method for programming a memory device are discussed. The method comprises selecting a cell to program, wherein the cell is coupled to a bit line, applying a first programming pulse, wherein the first programming pulse comprises applying a first voltage to the bit line, verifying if the cell is programmed after applying the first programming pulse, and applying a second programming pulse to the bit line after applying the first programming pulse if the cell is not programmed after applying the first programming pulse, wherein second programming pulse comprises applying a second voltage to the bit line, wherein the second voltage is different than the first voltage.

To increase their speed of operation, devices are continuously scaled. For example, channel lengths of floating gate based non volatile memory devices are decreased. Because programming voltages remain unchanged, short channel behaviors become problematic during programming when the channel lengths decrease. Typically, to program a selected device, a high drain voltage (Vd) is applied to the bit line of the selected device and a gate voltage (Vg) is applied to a word lines. Since other devices that are not to be programmed (unselected devices) are also coupled to the bit line of the selected device but the word line they are coupled to has a Vg of zero, the unselected devices experience Drain Induced Barrier Lowering (DIBL). DIBL lowers the threshold voltage (Vt) of the unselected devices and introduces high column leakage during programming in which a high Vd is applied to the selected bit line.
In addition, when on volatile memory devices are scaled the thickness of a tunnel oxide is decreased. This decrease in oxide thickness increases read disturb or Low Temperature Date Retention (LTDR) from a low Vt state. One solution to reduce LTDR is to reduce the natural ultraviolet Vt of the device. However, the short channel effects, such as DIBL are more severe when the natural ultraviolet Vt is decreased. Thus, column leakage becomes larger, which negatively impacts programming efficiency and time.
Thus, a need exists for a programming scheme that reduces LTDR and does not decrease programming efficiency.
Skilled artisans appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help improve the understanding of the embodiments of the present invention.

Memory structure and method of programming


The method and apparatus herein identifies tunable duplexer in a communication system. The tunable duplexer includes a tunable receiver filter, a tunable transmitter filter, a variable receiver phase shifter, and variable transmitter phase shifter. Each filter and phase shifter is optimized based on characteristics of impedance within the duplexer. The duplexer may be adjusted to changing environments or desired changes in the frequency of operation, reducing circuitry architecture and providing greater flexibility in communication function. The method commences by tuning tunable filters within the duplexer and then optimizing phase shifters within the duplexer for adjusting impedance matching with antenna and isolating the receiver from the transmitter during duplexing operations. Optimizations and calibration may be performed during manufacture, upon initialization of the system, or during operation of the communication device. The modes of calibration and operation may be generalized as “predefined” (for known environments and frequencies) or “adapt,” where antenna impedance or frequency of operation changes.

In communication devices, duplexers functionally provide the ability to receive and transmit signals while utilizing the same antenna. In usual transmission operations of a communication system, audio signals, which are typically fed into a microphone, are converted to a modulated signal by a modulator that is then converted to a designated carrier frequency by an oscillator. Thereafter, the signal passes through an interstage filter, which selects only a signal having a desired transmission frequency, and is then amplified to the desired signal intensity by a power amplifier, the output of which is fed to an antenna duplexer. The antenna duplexer passes only the signals of the designated transmission frequency to the antenna, which transmits the signal as a radio signal into the air.
In receiving operations, a signal received by the antenna is transmitted to the antenna duplexer to select only a signal of a designated frequency. The selected signal is generally amplified by a low-noise amplifier and transmitted through a signal converter where only a desired characteristic or signal is selected by filters within the signal converter. The signal is down-converted to baseband and then manipulated as an audio signal. An antenna duplexer is usually positioned between the antenna and down-converter circuits and has such a function that the transmission signal and the reception signal are isolated to prevent interference between the two types of signals.
Electrically a duplexer is a device using distinctly tuned resonant circuits to isolate a transmitter from the receiver, allowing the transmitter and the receiver to operate on the same antenna at the same time without the transmitter adversely affecting the receiver. Duplexers use filters, such as various pass band filters and notches to accomplish isolation and continuity in signal transfer. In duplexer operation, filters must pass the desired signal while rejecting as much as possible of the undesired signals. For example, all of the transmitter's energy is not contained in just the desired frequency; transmitters characteristically generate a wide band noise for a considerable width around the center frequency. Therefore, a reject band [or notch] filter may be used to refine the signal within the device. Within the art, a combination of complex or simple filters may be used to obtain the desired performance of the communication device.
The antenna duplexer necessarily has at least a transmission filter and a reception filter, and in order to prevent interaction between the transmission filter and the reception filter, it also has a matching circuit, which is also referred to as a phase matching circuit or a line pattern for phase matching. While an antenna operates as an interface between circuits and space, which transfers power between space and the transmitter (Tx) or receiver (Rx), its impedance acts as the load for the Tx or the input impedance for the Rx. This impedance is determined by such factors as electrical properties or environmental properties (e.g. surrounding conducting or insulating objects), generally categorized as ohmic resistance and radiation resistance but is also partially manifested as reactance. As with all devices that transfer energy, an antenna correspondingly has efficiency associated with its operation, namely, the measurement of the dissipated power within the antenna due to ohmic resistance of the antenna conductor and other losses. Optimized impedance matching to the antenna maximizes the power transferred between space and circuits.
Within the design of communication devices, computer simulations, tedious manual computations, or Smith Charts may be utilized to perform impedance matching. Manual computations typically involve complex conjugate calculations and numerous equations. Computer simulations are typically dedicated to design functions and not impedance matching. Such simulations require designer familiarity with multiple data inputs and their associated correct formats, and understanding voluminous results data. Smith Charts, or simulations that incorporate Smith Charts, are not only used for finding matching networks component values or maximum power transfer but are also used with such design tasks as optimizing for the best noise figures, ensuring quality factor impact, and assessing stability analysis.
In addition to the generalization of duplexer complexities, recent development of the mobile phone has resulted in the expansion of diverse functionality in communication devices that further complicates duplexer design. For example, increased device functions such as dual mode (e.g., a combination of an analog mode and a digital mode, or a combination of digital modes, such as TDMA (time division multiple access) or CDMA (code division multiple access)), and a dual band (e.g., a combination of an 800 MHz band and a 1.9 GHz band, or a combination of a 900 MHz band and a 1.8 GHz band or a 1.5 GHz band) have been increasing the complexity of device architecture and circuitry. Increased implementation of frequency related functions affect antenna bandwidth. Antenna bandwidth is generally the range of frequencies over which the antenna can operate while some other characteristic remains in a given range. Therefore, increased frequency ranges increases demand for performance over a number of frequency channels, or a wide bandwidth antenna. Moreover, to support these multiple, diverse functions while maintaining proper isolation and reliable signal transfer between Tx and Rx operations, present communication devices use fixed, redundant circuitry, such as an increased quantity of switches and filters to compensate and broaden duplexer capabilities. Accordingly, such increased use and quantity of filters synergistically creates the need for optimizing filter performance.
Ubiquitous to the electronics field and universal to the communications field is the continuing demand for component reduction and high performance devices. Elimination of redundant components, functions, or circuitry is highly desired in communication electronics. Similarly desired is increased performance in communication devices without increasing device size, weight, or price. Within the field, these individual design factors [goals] are frequently pursued independently while balancing impacts to other factors. Common within the field is the optimization of one factor, such as device performance, while maintaining or sub-optimizing another factor, such as redundant components.
Although frequency ranges of the communication system often determine the type of technology used in device design (e.g., MEMS (Micro-Electro-Mechanical Systems)), prospective uses of the radio frequency spectrum are driving the need for higher performance devices with reduced circuitry/architecture. For example, the FCC sanctioned "cognitive radio" purports to use non-assigned spectrum based on the condition that there be no present, real-time use occurring. This projected use imports future designs and concepts that are time-based with an increased number of bands—further demanding higher performance and greater architecture.
Given the aforementioned duplexer issues, tunable duplexers provide a form of alternate solutions. Present tunable duplexer designs and techniques incorporate one of two approaches: (1) using multiple filters for increased demand in bandwidth on each side of circuitry, i.e., for the Tx side and one for the Rx side, or (2) incorporating the use of a circulator, a bulky three port device for directional management and isolation. However, these schemes have proven limitations in today's communications field. For example, the use of multiple filters frequently incorporated the use of switched filters and substantially increased the amount of circuitry needed to accomplish functionality. This design approach also makes for difficult or clumsy impedance matching and performance solutions with either multi-throw switches or cascaded lower throw switches, in addition to the multiple filters. This approach is in conflict with the goal of optimizing filter performance. For the second approach, circulators are big, heavy, and are typically narrow band components, which use magnets for appropriate biasing. Additionally, broader band applications or needs result in larger componentry (e.g., circulator matching, support circuitry, etc.). Also, isolation capabilities within circulators are limited. Therefore, if not properly aligned, circulators adversely effect the optimization of filters.
In general, obstacles encountered by present day duplexers include, but are not limited to, impedance matching, reliable and quality signal transfer, and complex or cumbersome filter designs to support increase functional demand and Tx-Rx isolation. Moreover, fixed filter designs are commonly used to sustain multiple bands. In the situations where tunable duplexers are used, present methods or designs are ineffective.
It is desirable, therefore, to provide a system and method that overcomes these and other disadvantages.


A method of segmenting a radiographic image into diagnostically relevant and diagnostically irrelevant regions comprising: acquiring a digital radiographic image including a matrix of rows and columns of pixels; detecting the initial background left point of a histogram of the image; detecting the foreground of the image; regenerating the background of the image by region growing; validating the background of the image; merging the background and foreground regions of the image as diagnostically irrelevant regions; and extracting the anatomy region of the image as the diagnostically relevant region.

The recent advance in digital radiographic imaging systems, such as the flat-panel based direct digital radiographic (DR) systems ("A high resolution, high frame-rate, flat-panel TFT array for digital x-ray imaging," Proceedings of SPIE Medical Imaging, Antonuk et al., vol. 2163, pp 118-128, 1994) and the storage phosphor based computed radiographic (CR) systems ("Introduction to medical radiographic imaging," Eastman Kodak Company, 1993) etc, allow the separation and optimization of image acquisition, processing, and display processes individually. The image pixel data are manipulated during the image-processing step so as to optimize the image information acquired on the radiograph and to help the radiologists to better perceive even the subtlest diagnostic details. Optimizing diagnostic details depends on the knowledge of the location and characteristics of both diagnostically relevant and diagnostically irrelevant regions in the radiograph. The scope of this invention therefore relates to the automatic segmentation of a digital radiograph into anatomy (diagnostically relevant regions), foreground and background (diagnostic irrelevant regions).
FIG. 1(a) shows an example of a foot radiograph acquired with CR. The foot was exposed at three viewing angles A, B, C using the same storage phosphor cassette but at different cassette regions. The anatomy in this radiograph is the foot and is considered diagnostically relevant. The regions in the radiograph where x-rays directly expose the storage phosphor are diagnostically irrelevant, which are later referred to as the background or direct exposure region. Collimation was used during the x-ray exposure to reduce unnecessary radiation to the anatomy that is irrelevant to diagnosis and to confine the x-rays to a local region of the cassette. The regions in the radiograph collimated outside the x-ray radiation field are diagnostically irrelevant, which are later referred to as the foreground region.
The work of Barski et al. taught a method of determining the direct exposure regions in a radiograph ("Determination of direct x-ray exposure regions in digital medical imaging," U.S. Pat. No. 5,606,587). However, this method uses a single value, namely background left point, to threshold the input image to generate a binary map. Although this method is suitable for the purposes for which it was intended, in the case when the direct exposure region has a large intensity non-uniformity, which can be caused by the non-uniform intensity distribution of the incident x-rays or by the exam requirements that need multiple views of the anatomy at different exposures levels another method may be needed. FIG. 1(b) shows an example of the result using Barski's method, which indicates that the background can be over-detected and under-detected at the same time. The thresholds used in this method also vary from one exam-type (bodypart and projection) to the other, which may not work well when exam-type information is unavailable.
Pieter disclosed a method to determine the foreground region in a radiograph ("Method of recognizing an irradiation field," European Patent 0,610,605). However, this method can only deal with single-exposed radiographs, and can not be used to completely segment the diagnostically relevant regions where there are two or more radiation fields in a single radiograph, such as the example in FIG. 1(a). To address this limitation, Piet et al disclosed an improved method of detecting the foreground regions ("Method of recognizing one or more irradiation fields," European Patent 0,742,536). However, both Pieter and Piet failed to teach a method for determining the background regions. Wang et al., showed a method based on Barski's direct exposure detection to determine the image foreground regions ("Method for recognizing multiple irradiation fields in digital radiography," U.S. Pat. No. 6,212,291). This method, however, still did not fulfill all of the needs of background detection.
Given the drawbacks and limitation of the prior art, there is a need for a method that is exam type independent and that can automatically segment digital radiographic images into anatomy, foreground, and background regions.

Method of segmenting a radiographic image into diagnostically relevant and diagnostically irrelevant regions


An apparatus and method for inspecting wafers at a reclaim factory is described. Embodiments of the invention describe an apparatus in which a wafer ID and wafer thickness may be simultaneously measured. A wafer is placed onto a sloped surface and positioned by aligning a notch in the wafer with a pin located on the surface, and by propping the wafer against a pair of laterally opposite restraints. In one embodiment, a foot-switch is used to trigger the simultaneous wafer ID and wafer thickness measurements.

1. Field of the Invention
The present invention relates to the field of reclamation and reuse of semiconductor material substrates. More particularly this invention relates to an apparatus and method for inspecting incoming and outgoing wafers at a reclaim factory.
2. Discussion of Related Art
The increasing process complexity and introduction of new materials to the field of integrated circuit (IC) fabrication has given rise to a greater number of processing steps; each of which must be tested for quality.
Test wafers including "dummy" or "control monitor" wafers are used to check the reliability of IC fabrication equipment. For example, dummy wafers are used to test new IC fabrication equipment prior to its implementation into the large-scale production process of ICs. A dummy wafer is cycled through the new equipment and the ICs formed on the dummy wafer are then examined to determine if they meet certain specified criteria indicating that the fabrication process was properly performed. Only then is the equipment implemented into the production of ICs. Thereafter, the dummy wafer may be discarded, or "recycled" by removing the depositing films and re-using the dummy wafer.
Once fabrication equipment is implemented into the production process, it must be periodically inspected by examining the fabricated ICs to ensure that it is functioning properly. Such quality assurance testing is typically performed on a daily basis, such as at the beginning of every working shift. During such testing, control monitor wafers are used in a trial process, such as film deposition, performed on the wafer. The control wafer is then examined to determine if it meets certain specified criteria indicating that the fabrication process was properly performed. Thereafter, the control wafer maybe discarded (to protect intellectual property, for example), or "recycled" by removing the depositing films and re-using the control wafer.
All of this quality assurance testing requires the use of a large number of wafers and increases the total cost of IC fabrication. Customers will typically recycle their wafers using their own equipment. However, each recycle roughens the wafer surface and after a few such cycles the wafers must be re-polished to meet fab specifications for such wafers to be used in their tools. These wafers are typically sent to a wafer reclaim vendor who provides the essential expertise and service for stripping and re-polishing the wafers to the customer's specifications and returning them to the customer for a service charge. In addition to meeting customer specifications, the wafer reclaim vendor must ensure than one customer's wafers do not become mixed with another customer's wafers. The method typically employed to accomplish this is to record each wafer's identification (ID) code at the incoming stage and then tracking that wafer through the entire process.
The reclamation cycle forms a loop in which used wafers are sent to a reclaim vendor, processed to meet fab specification, and sent back to the customer for reuse as test wafers. Customers optimize cost-cutting by reducing the number of test wafers to be used, and by using them as many times as possible. This requires maintaining a high ratio of reclaimed wafers to total test wafers. In order to meet customer demands, wafer reclaim factories must in turn optimize the wafer reclaim process and offer cycle times in the order of days rather than weeks.
A typical wafer reclamation process includes multiple preliminary steps of incoming wafer inspection, ID detection, and sorting of the wafers into groups. The grouped wafers are then subjected to removal steps such as grinding and/or etching particular materials, followed by polishing and cleaning. The process is finalized with a final multi-step outgoing wafer inspection to ensure that the proper amount of material was removed, and that customer specifications such as those for surface particles and wafer flatness are met. A lot of attention has been given to optimization of the critical removal steps where proprietary grinding and etching steps are typically performed. However, what is additionally needed is a way to reduce overall cycle times at the incoming and outgoing wafer inspection steps.

Apparatus for improving incoming and outgoing wafer inspection productivity in a wafer reclaim factory


A spread spectrum clock generator capable of generating a smooth spread spectrum clock while suppressing an increase in the size of the circuitry includes a phase interpolator, receiving a clock signal from a clock input terminal and a control signal (an up signal and/or down signal) are input, for adjusting the phase of an output clock signal in accordance with the control signal and outputting the resultant clock signal, and a control circuit for counting the clock signal that enters from the clock input terminal and outputting the control signal to the phase interpolator, the control signal varying the phase of the output clock signal based upon the count result. The phase of the output clock signal from the phase interpolator varies with time and is frequency-modulated within a prescribed frequency range.

When a clock generator in an electronic device generates a single frequency, emission increases at the frequency and higher harmonics. For this reason, use is made of a spread spectrum clock generator that reduces the peak of unnecessary emissions by frequency modulation and diminishes EMI (electromagnetic interference).
A PLL (phase-locked loop) in which a pulse-swallow frequency divider is provided in a feedback counter generally is used as a conventional spread spectrum clock generator of this kind (e.g., see M. Sugawara, T. Ishibashi, K. Ogasawara, M. Aoyama, M. Zwerg, S. Glowinski, Y. Kameyama, T. Yanagita, M. Fukaishi, S. Shimoyama, T. Ishibashi and T. Noma, "1.5 Gbps, 5150 ppm Spread Spectrum SerDes PHY with a 0.3 mW, 1.5 Gbps Level Detector for Serial ATA", Symposium on VLSI Circuits Digest of Technical Paper 5-3, FIG. 1, June/2002). This PLL implements frequency modulation by affording two integers A and A-1 as divider ratios and switching between A and A-1. By changing the proportions of A and A-1 at predetermined fixed intervals, average frequency f is varied to thereby generate a spread spectrum clock.
With a PLL having a pulse-swallow frequency divider provided in a feedback counter, a single pulse of a step phase error enters the PLL as an input when the frequency divider is changed over. Since the PLL is in the negative feedback loop, a transient response is caused by the entered step phase error. It is expected that if the damping factor of the negative feedback loop is large, the clock frequency will vary out of specs owing to the transient response. If the damping factor is small, on the other hand, there is a possibility that the stability of the loop will be lost. Furthermore, since the characteristic of a spread spectrum clock generator is decided by control of the pulse-swallow frequency divider and the overall characteristic of transient response due to step phase error, a large number of design parameters exists and labor expended in optimizing design increases.
It should be noted that the PLL described in the above-cited reference is equipped with the pulse-swallow frequency divider and is so adapted that a smooth characteristic is obtained by using post-filtering. However, the reference is silent on information (measures) regarding a fluctuation in the PLL characteristic.
A spread spectrum clock generating circuit having a PLL, which is equipped with a plurality of program counters, and a frequency modulating circuit also is known [e.g., see the specification of Japanese Patent Kokai Publication No. JP-A-7-235862 (pages 9, 10 and FIGS. 6, 7, 8 and 9)].
Also known is a clock generating apparatus comprising a clock generator for generating m-phase clock signals having a phase difference between them; a selection processor for successively selecting one of the m-phase clock signals generated by the clock generator to thereby generate a second clock signal; and a dithering controller for supplying the selection processor with a control signal so that the phase of the second clock signal obtained from the selection processor will fluctuate within a prescribed range and the peak of a spectrum will be dispersed (e.g., see the specification of Japanese Patent Kokai Publication No. JP-P2001-148690A (pages 3 and 10 and FIGS. 3 and 11)]. The clock generating apparatus of this patent reference is equipped with a delay circuit or ring oscillator as the m-phase clock generator. FIG. 8 is a diagram illustrating the structure of the clock generator described in this patent reference, the generator using a ring oscillator 110 to generate a 5-phase clock. As shown in FIG. 8, five inverting delay circuits 111 to 115 are connected in ring form and clocks c0 to c4 of five phases are extracted from the outputs of the respective delay circuits via buffers 116 to 120, respectively. Reference numerals 121 to 125 denote frequency divider circuits.
In the prior art in which plural (m) clock generators such as a plurality of delay circuits are used in generating multiple-phase (m-phase) clock signals, as described in this patent reference, the amount of delay in the delay circuits fluctuates owing to changes in power-supply voltage and operating temperature, etc., if the delay circuits are constructed in an integrated circuit. Accordingly, a clock generator of m different phases requires the provision of delay circuits of m or more phases for the purpose of accommodating for the amount of fluctuation. As a consequence, control is complicated and it is necessary to finely adjust the amount of delay of the delay circuits.
Further, with the arrangement described in this patent reference, m (five in FIG. 8) clock generators are provided to deal with phase lead or lag of the clock. When the phase of a clock makes one full cycle, a smooth, seamless transition is desired with the same amount of delay. However, it is difficult to achieve a smooth, seamless transition owing to the fine adjustment of amount of delay and the use of m or more clock generators.
In a case where clocks of m different phases are generated by the ring oscillator 110, as shown in FIG. 8, this is technically feasible when the number of m-phase ring oscillators is small. In order to stabilize frequency, however, PLL (phase-locked loop) techniques are required. Further, if it is attempted to finely adjust phase resolution by increasing the number of clock generators for m different phases, the oscillating frequency of the ring oscillator will decline and the required frequency will no longer be obtained.
[Non-patent Document 1]
M. Sugawara, T. Ishibashi, K. Ogasawra, M. Aoyama, M. Zwerg, S. Glowinski, Y. Kameyama, T. Yanagita, M. Fukaishi, S. Shimoyama, T. Ishibashi and T. Noma, "1.5 Gbps, 5150 ppm Spread Spectrum SerDes PHY with a 0.3 mW, 1.5 Gbps Level Detector for Serial ATA", Symposium on VLSI Circuits Digest of Technical Paper 5-3, FIG. 1, June/2002
[Non-patent Document 2]
S. Sidiropoulos and Mark Horowitz et. al., "A Semi-Digital DLL with Unlimited Phase Shift Capability and 0.08-400 MHz Operating Range," ISSCC 1997 pp. 332-333
[Patent Document 1]
Japanese Patent Kokai Publication No. JP-P2001-148690A (pages 3 and 10 and FIGS. 3 and 11)
[Patent Document 2]
Japanese Patent Kokai Publication No. JP-A-7-235862 (pages 9, 10 and FIGS. 6, 7, 8 and 9)
[Patent Document 3]
Japanese Patent Kokai Publication No. JP-P2002-190724A (pages 8 and 9, FIG. 6)

Spread spectrum clock generating apparatus


Disclosed herein is an OLED (Organic Light Emitting Display) device. A switching thin-film transistor configured to be an oxide semiconductor thin-film transistor is disposed in a first pixel. A second pixel is adjacent to the first pixel in the direction in which data lines are extended. A switching thin-film transistor configured to be an LTPS (Low Temperature Poly-Silicon) thin-film transistor is disposed in the second pixel. The switching thin-film transistor of the first pixel and the switching thin-film transistor of the second pixel are connected to the same gate line. A pixel and another pixel adjacent to the pixel connected to a gate line in common, so that it is possible to provide an OLED device with high aperture ratio and high resolution.

1. Field of the Invention
The present invention relates to an OLED (Organic Light Emitting Display) device. More particularly, the present invention relates to an OLED device achieving high aperture ratio and being advantageously applied to high resolution devices, in which an oxide semiconductor thin-film transistor having an active layer made of an oxide semiconductor and an LTPS (Low Temperature Poly-Silicon) thin-film transistor having an active layer made of an low temperature poly-silicon are supplied with the same gate voltage from the same gate line. Further, the present invention relates to an OLED device in which an oxide semiconductor thin-film transistor and an LTPS thin-film transistor are used as a switching thin-film transistor and a driving thin-film transistor for driving a single organic light-emitting element.
2. Description of the Related Art
As the era of information technology has begun, the field of display that visualizes the electrical information signals has been rapidly developing rapidly. In accordance with this, various flat display devices which are thinner, lighter and more efficient in power consumption have been developed fast to replace existing CRTs (Cathode Ray Tubes)
Examples of such flat display devices include an LCD (Liquid Crystal Display) device, an OLED (Organic Light Emitting Display) device, an EPD (Electrophoretic Display) device, a PDP (Plasma Display Panel) device, a FED (Field Emission Display) device, an EWD (Electro-Wetting Display) device, etc.
Among these, an OLED device emerges as the next generation display device having a self-emitting characteristic since it exhibits a good performance on LCD devices in terms of viewing angle, contrast, response time, power consumption, etc.
Commonly, flat display devices require a flat display panel as an essential element to produce images. Such a flat display panel includes a pair of substrates laminated on one another, with a layer of a luminescent material or a polarizing material between the substrates. The substrates of such a flat display panel are divided into emission regions in which arrays of pixels emit light, and element regions in which circuit elements to drive the pixels are disposed. In particular, in the element regions, a plurality of thin-film transistors (TFT) is disposed to drive the pixels and to operate the circuit elements.
An OLED device includes organic electroluminescent diodes with each consisting of an anode electrode, a film of organic compound, and a cathode electrode. Such an OLED device may be driven in a passive matrix manner in which an organic electroluminescent diode is connected between a gate line and a data line in a matrix to form a pixel, or in an active matrix manner in which the operation of a pixel is controlled by its thin-film transistor working as a switch.
In a pixel driving unit of an OLED device driven in an active matrix manner, a switching thin-film transistor of a pixel is operated by the voltage output from a circuit element via a gate line. When a data value of pixel goes through a data line to be stored in a storage capacitor, a pixel-driving current corresponding to the data value flows from a driving thin-film transistor to an organic electroluminescent diode causing the pixel to emit light as a result.
As customer's expectation for OLED devices is ever increasing, research is going on into OLED devices with high aperture ratio and high resolution. However, there are limits to reduce the sizes of thin-film transistors, capacitors and various types of supply lines required for driving OLED devices. Accordingly, efforts to implement OLED devices with high aperture ratio and high resolution are on going.
Previously in OLED devices, LTPS thin-film transistors solely or oxide semiconductor thin-film transistors solely have been used as switching thin-film transistors and driving thin-film transistors. When only one type of thin-film transistors is used, large area has been required for providing enough space for storage capacitors. To that end, space for storage capacitors needs to be large enough, so that the size of a pixel itself can be increased or the area occupied by a pixel driving unit in the pixel can become larger. This makes it difficult to manufacture a high-resolution or high-transparent panel.


A torsion device comprising: a first part comprising a first resilient torsion member including: a first support end; a first free end spaced from the first support end; and a first engagement region; a second part comprising a second resilient torsion member including: a second support end; a second free end spaced from the second support end; and a second engagement region; wherein the second part is rotatable relative to the first part about an axis of rotation (A) between a first angular position and a second angular position, and the first and second torsion members are configured to urge the first and second engagement regions together to cause flexure of at least one of the first and second resilient torsion members as the second part rotates relative to the first part from the first angular position to the second angular position.

Torsion springs are typically constructed to provide a specified torsion force over a specified angle of rotation. Typically designs are based on coiled flat springs where the force is limited but the angle can be large or on large cross-section coil springs where the angle is limited but the force is large.
Difficulty arises where a large force and substantial angle of movement is required. Conventional solutions typically require a very heavy and large form of spring that allows the material of which the spring is constructed to stay within its limits of stress while achieving the necessary displacement. For example, to achieve a required force a spring may require a certain diameter of element and at a given diameter the element is coiled until there are sufficient turns to enable the required angle of movement to be possible without exceeding the material stress or strain limits. This results in a heavy and bulky solution.
When considering vehicle suspension systems, which are typically (though not exclusively) linear spring arrangements spring mass and volume become important due to the fact that often the suspension mass adds to the wheel unsprung mass and so has direct negative impact on the effectiveness and response of the dynamic behaviour of the suspension.
Torsion bar systems have been used to help alleviate this problem, but this solution carries the negative attribute of needing long lengths (often heavy though not part of the unsprung mass) of material in order to provide for the necessary stress and strain constraints of any chosen material.
In all the above examples the cost of the suspension system is relatively high and adds cost, complexity and mass to the vehicle.
One of the main problems with suitable spring materials is that they are either constrained with displacement if large force is required, for example various types of steel, or constrained with limited force if large displacement is required, for example plastics or composites. Additionally present vehicle suspension systems require additional devices to damp out oscillatory motion. These "dampers" (or shock absorbers) are typically fitted directly between a moving wheel axle and chassis of a vehicle. They take up further valuable space and add further cost and complexity to the suspension system.
The present applicant has identified the need for an improved torsion device that overcomes or at least alleviates problems associated with the prior art.


An optical-axis deflection type laser interferometer includes a reference ball serving as a measurement reference, a retroreflecting means disposed at an object to be measured, a laser interferometer length measuring apparatus outputting a measurement value between the apparatus and the retroreflecting means, and a rotational mechanism that rotates a beam projected from the laser interferometer length measuring apparatus around the reference ball. The laser interferometer additionally includes a displacement gauge that measures an error caused by a relative motion between the reference ball and the laser interferometer length measuring apparatus, and a rectilinear movement mechanism that displaces these in a direction of an optical axis of a measurement beam with respect to the reference ball while maintaining a relative positional relationship between the laser interferometer length measuring apparatus and the displacement gauge. With this structure, calibrating the displacement gauge without preparing a special calibrating device becomes possible, thereby securing traceability thereby securing traceability.

1. Field of the Invention
The present invention relates to an optical-axis deflection type laser interferometer that includes a reference ball serving as a measurement reference, a retroreflecting means disposed at an object to be measured, a laser interferometer length measuring apparatus that outputs a measurement value according to an increase or a decrease in distance between the apparatus and the retroreflecting means, and a rotational mechanism that rotates a beam projected from the laser interferometer length measuring apparatus around the reference ball, the laser interferometer measuring a distance between the laser interferometer and the retroreflecting means that makes an optical axis of an outgoing beam projected from the laser interferometer length measuring apparatus mounted on the rotational mechanism and an optical axis of a return beam returned to the laser interferometer length measuring apparatus parallel to each other, based on center coordinates of the reference ball. The present invention relates to a calibration method of the laser interferometer, relates to a correcting method of the laser interferometer, and relates to a measuring method of the laser interferometer. More specifically, the present invention relates to an optical-axis deflection type laser interferometer that can secure traceability by the length standard without using a special device, relates to a calibration method thereof, relates to a correcting method thereof, and relates to a measuring method thereof.
2. Description of the Related Art
An optical-axis deflection type laser interferometer (also called a "tracking laser interferometer") is known. This laser interferometer operates in the following way. As shown in FIG. 1, a laser beam (hereinafter, referred to as a "measurement beam") 22 is projected from a laser interferometer length measuring apparatus 20 toward a retroreflecting means (also called a "retroreflector") 12 disposed at a to-be-measured object 10, and is reflected in the backward direction by the retroreflecting means 12. The displacement of the retroreflecting means 12 is detected by use of the interference of the laser beam reflected therefrom, and a tracking operation is performed by use of a change in position of the optical axis of the measurement beam 22 by a two-axis rotational mechanism 30. In FIG. 1, reference numeral 24 designates a light source, and reference numeral 32 designates a deflective plane mirror of the two-axis rotational mechanism 30.
According to this optical-axis deflection type laser interferometer, based on information about the return beam returning from the retroreflecting means 12 that serves as a target, the distance from the apparatus to the target can be measured by the laser interferometer length measuring apparatus 20 with high accuracy.
However, the optical-axis deflection type laser interferometer has technical difficulties in making the precision of the two-axis rotational mechanism 30 as high as the precision in measurement of the laser interferometer. Especially, as in the optical system shown in FIG. 1 in which the direction of the measurement beam 22 is deflected by, for example, the plane mirror 32 attached to the two-axis rotational mechanism 30, the two-axis rotational mechanism 30 has a precision limit, and, in addition, it is difficult to allow a beam to accurately strike the rotational center of the plane mirror 32. These make it difficult to achieve high precision.
Therefore, as shown in FIG. 2, European Patent EP0919830A2 (hereinafter, referred to as Patent Document 1) discloses that a relative displacement between the surface of a reference ball 34 disposed at the center of the two-axis rotational mechanism 30 and the laser interferometer length measuring apparatus 20 is measured with a laser beam 26 projected in the exactly opposite direction with respect to the target (12), in addition to the measurement of the retroreflecting means 12 serving as a target. In FIG. 2, reference numeral 36 designates a carriage used to mount the laser interferometer length measuring apparatus 20 on the two-axis rotational mechanism 30, and reference numeral 40 designates a support used to fasten the reference ball 34.
However, the optical system disclosed by Patent Document 1 has a disorder of an interference wavefront or a reduction in light quantity with respect to a rotational error (i.e., runout) in a direction perpendicular to the optical axis. Additionally, it has become apparent that the optical system is not necessarily robust in respect of a change in the optical path length. Therefore, high-cost specifications are required for the rotational accuracy of the two-axis rotational mechanism 30. Additionally, the problem of the light quantity ratio of the laser interferometer length measuring apparatus 20 is included therein. In more detail, the laser interferometer length measuring apparatus 20 measures a phase difference between a reference beam whose optical path is unchangeably fixed there inside and a measurement beam 22 that travels toward the target (12) and that returns backwardly therefrom. Therefore, if there is a great difference in light quantity between the reference beam of light and the measurement beam of light, the contrast of interference fringes cannot be sufficiently secured, and, as a result, interference measurement cannot be performed with high accuracy. However, in the optical system disclosed by Patent Document 1, the measurement beam is first projected and reflected to and from the reference ball 34, and is then projected and reflected to and from the target (12). The light quantity of the measurement beam that has returned in this way is remarkably attenuated, and hence a difference in light quantity with respect to the reference beam that is generally regarded as not being easily attenuated causes a large problem.
On the other hand, the present applicant proposes an optical system shown in FIG. 3 in Japanese Published Unexamined Patent Application No. 2007-57522 (not yet published at the priority date thereof: hereinafter referred to as Patent Document 2). In this prior invention, a motion error of the two-axis rotational mechanism 30 with respect to the reference ball 34 is measured with a displacement gauge 50 separately mounted on a carriage 38 formed integrally with the carriage 36, not with a measurement beam of the laser interferometer length measuring apparatus 20. According to this prior invention, a highly accurate optical-axis deflection type laser interferometer can be, of course, realized with reference to the reference ball 34, and the precision requirement against the two-axis rotational mechanism 30 can be greatly eased without sacrificing robustness with respect to an error component in the direction perpendicular to the optical axis. Additionally, according to this prior invention, the measurement beam of the laser interferometer length measuring apparatus 20 is projected only onto the target (12), and hence the disadvantage of the attenuation of the measurement beam that becomes a problem in the technique of Patent Document 1 is greatly reduced.
However, in this prior invention, a motion error in the direction of the optical axis of the two-axis rotational mechanism 30 with respect to the reference ball 34 is detected, and hence there is a need to additionally provide the displacement gauge 50. Since the optical-axis deflection type laser interferometer has been expected to perform highly accurate measurement that is traceable to the length standard, the technique to secure the traceability of the displacement gauge 50 has been expected to be achieved.

Optical-axis deflection type laser interferometer, calibration method thereof, correcting method thereof, and measuring method thereof