In a steering apparatus, a differential lock mechanism has a lock holder in which a plurality of groove portions are formed on an outer periphery thereof, and selectively allows and prohibits to generate a difference of steering amount in the rotational direction between an input shaft and an output shaft by selectively engaging and disengaging an engaging portion with respect to the groove portions. A rotation sensor detects the position in the rotational direction of the lock holder during one rotation of the lock holder and repeatedly detects the same sensor pattern being output a plurality of times. A variable transfer ratio unit ECU detects which groove portion, from among the plurality of groove portions, the engaging portion is engaged with using the sensor pattern output by the rotation sensor when a side portion of one of the groove portions is pressing against a side portion of the engaging portion.

1. Field of the Invention
The invention relates to a steering apparatus, and more particularly, a steering apparatus in which the steering angle of a wheel can be changed with respect to the steering angle of a steering wheel.
2. Description of the Related Art
In recent years technology has been developed in which a variable transfer ratio unit, which allows the transfer ratio indicative of the steering angle of a wheel to be changed with respect to the steering angle of a steering wheel, is interposed in a steering shaft. This variable transfer ratio unit changes the transfer ratio by generating a difference of the steering amount between an input shaft and an output shaft in rotation direction. When a vehicle is provided with this kind of a variable transfer ratio unit, a differential lock mechanism is provided which selectively allows and prohibits to generate a difference of the steering amount between the output shaft and the input shaft to enable safer steering operation. One known differential lock mechanism includes a lock holder having a plurality of groove portions in the outer periphery thereof, and an engaging member that selectively engages and disengages with respect to the groove portions. It should be noted that the term "engage" in this specification refers to the engaging member entering or being anywhere in one of the groove portions. Likewise, the term "disengage" in this specification refers to the engaging member withdrawing from or no longer being anywhere in one of the groove portions.
In order to achieve suitable steering control in a steering apparatus having this kind of a variable transfer unit, Japanese Patent Application Publication No. JP-A-2004-58894, for example, proposes a vehicle steering apparatus in which the play angle when a lock arm is inserted into a concave portion is set to be less than the rotation angle of a motor when a different detection signal is output. Also, Japanese Patent Application Publication No. JP-A-2004-123083, for example, proposes a vehicle steering apparatus provided with a lock holder which rotates together with a motor and in which a plurality of first concave portions are formed in the circumferential direction on the outer periphery, and a deeper second concave portion is formed at one end portion of each of the first concave portions.
In order to appropriately change the steering angle of the wheels with respect to the steering angle of the steering wheel, it is imperative to know the positional relationship in the rotational direction between the input shaft and the output shaft when the differential lock was released. In Japanese Patent Application Publication No. JP-A-2004-58894 described above, however, there is no mention of technology for detecting which groove portion of the lock holder the lock arm is engaged with when the ignition switch is turned on, for example. In Japanese Patent Application Publication No. JP-A-2004-58894, a detection signal that is the same as the detection signal indicating that the lock arm is engaged with another groove portion, not the groove portion that the lock arm is actually engaged with, can be output from a rotation sensor. Unless it is known which groove portion of the lock holder the lock arm is engaged with, it is difficult to know the positional relationship in the rotational direction between the input shaft and the output shaft. Also, Japanese Patent Application Publication No. JP-A-2004-123083 does describe technology for detecting the groove portion that the lock arm is engaged with by detecting the width of the groove portion. However, this requires that the widths of the groove portions formed in the lock holder all be different, and the operation for that detection is also complicated.


A system may include a processor, a printing device, a communication interface operably connected to the processor, and a computer-readable storage medium in communication with the processor. The computer-readable storage medium may include one or more programming instructions for identifying a carbon credit account associated with at least a user, receiving a print job request from the user, receiving a carbon emission value for the print job request, determining whether to accept the print job request based on the carbon emission value and the carbon credit amount, and performing, via the printing device, the print job request in response to accepting the print job request. The carbon credit account may include a carbon credit amount.

Global awareness has led to increased concern regarding the amount of carbon or equivalent emissions being released into the atmosphere. A measurement of these emissions is generally referred to as a carbon footprint. Many entities are interested in calculating their carbon footprint. Such calculations can assist with determining methods of reducing associated emissions. For example, factors can be monitored such as gas usage, electricity usage and mileage associated with travel to calculate a carbon footprint. Carbon footprints can be calculated for a personal household, an international corporation, or any other entity.
Within a business environment, office products tend to consume large amounts of energy and greatly contribute to an entity's carbon footprint. For example, office products can include fleets of equipment such as copiers, printers and multi-function devices. Energy costs associated with print jobs performed by these office products is another contributing factor to the entity's carbon footprint.

Systems and methods for carbon footprint job based accounting


An improved igniter and cable connector assembly for turbine engines. An igniter mounting adapter is secured to the engine. The igniter slides into a hole through the adapter and is retained by an enlarged head on the igniter. An annular seal is positioned around a high voltage terminal on the igniter head and a terminal on the cable connector is positioned against the igniter terminal. The cable connector is secured to the adapter, for example, by either a clamp assembly or a coupling nut or a quick release connector. As the cable connector is secured to the adapter, the seal is compressed between the igniter and connector insulators and, optionally, the connector terminal is rotated and pressed against the igniter terminal to establish a reliable electrical contact. The connector and igniter terminals preferably have mating conical or spherical surfaces, one of which may be an annular segment to provide an increased electrical contact area.

Igniters for use in aircraft turbine engines are typically formed with a metal shell surrounding an insulator. The shell is threaded to engage a threaded igniter opening in the engine. A high voltage terminal is recessed well within a free end of the insulator. A mating high voltage cable connector has a projecting insulator which supports a terminal. The connector insulator extends well into the igniter insulator to establish a long flashover path between the high voltage terminals and the grounded igniter shell. This construction results in a large profile for prior art ignitor and cable connector assemblies. When one common prior art cable connector is secured to an igniter, the cable insulator projects into the igniter insulator and a spring in the cable connector presses the cable terminal against the igniter terminal to establish a high voltage connection. Typically, contact between the terminals takes place only at a point or over a small surface area. An appropriate annular seal is located between the igniter and the cable connector to keep contaminants from entering the space between the igniter and connector insulators. A separate spring may be provided in the connector to compress the seal against the igniter. Any contaminants entering the terminal region may result in igniter and/or cable failure due to flashover. Ideally, the seal will also prevent air from escaping from the space surrounding the terminals when the iqniter is operated at high altitude. As the air pressure across a gap decreases, the flashover voltage required to jump the gap also decreases.
There are many problems with the design of present state of the art igniters and igniter cable connectors. The large number of component parts in aviation engine igniters and igniter cable connectors results in a high manufacturing cost, a large profile and an excessive weight. There is difficulty in establishing and maintaining a good seal between the igniter and the connector and in maintaining a good electrical contact between the igniter and the connector terminals. Operating failures can occur at the seal and also at the contact point between the high voltage connector terminal and the igniter terminal. Any arcing between the terminals caused by poor surface contact will eventually lead to igniter or cable failure.


The invention provides an adenoviral vector comprising (a) at least a portion of an adenoviral genome comprising a major late transcription unit containing a terminal exon, wherein the terminal exon comprises a 5′ splice acceptor DNA sequence element and a 3′ polyadenylation signal sequence, and (b) a non-native nucleic acid sequence encoding a protein that does not contribute to the adenoviral vector entry into a host cell, wherein the non-native nucleic acid sequence is positioned within the terminal exon, such that the non-native nucleic acid sequence is selectively expressed in cells within which the adenoviral vector can replicate. The invention further provides an adenoviral vector composition and a method for treating or preventing a pathologic state in a mammal, comprising administering to the mammal the adenoviral vector composition of the invention in an amount sufficient to treat or prevent the pathologic state in the mammal.

By convention, the adenovirus life cycle is divided into two phases, the early and the late phase, which are separated by the onset of viral DNA replication and characterized by the expression of specific subsets of the viral genome. In the early phase, the early genes E1, E2, E3, and E4 are maximally expressed (E1b, E2, E3, and E4 expression being activated by the immediate early gene E1a (see, e.g., Berk et al., Annu. Rev. Genet., 20:45-79 (1986)), and the major late transcription unit (MLTU) is expressed at very low levels and is attenuated. At the onset of viral DNA replication, a marked switch in gene expression occurs, resulting in the reduction of expression of the early genes and an increase in activation of the late genes, most of which are translated from mRNAs originating from the MLTU.
The MLTU is 25 kB in length and contains six polyadenylation (polyA) sites, five that are unique to the MLTU (L1 through L5) and one used by both the E3 transcription unit and the MLTU (see, e.g., Prescott et al., Mol. and Cell. Biol., 17(4):2207-2216 (1997)). Each polyA site is associated with several potential splice acceptors, and all 5′ terminal exons are spliced to a common tripartite leader (see, e.g., Nevins et al., Adv. Virus Res., 26:1-35 (1981)). Due to complex alternative RNA splicing, each late region produces multiple mRNAs. Indeed, during the late stage of adenovirus infection, all six polyA sites are used in conjunction with a variety of splice acceptors to produce a minimum of 45 different mature mRNAs. The extremely high level of mRNA production and the novel splicing/polyadenylation capacity of the MLTU are essential to the production of adenoviral virions.
Recombinant adenoviral vectors characterized as having a whole or partial deletion of one or more early region genes have been extensively studied. Many of these recombinant adenoviral vectors are engineered to contain a nucleic acid sequence encoding a therapeutic factor prior to being delivered to a population of cells for gene therapy. Limitations remain, however, for the production of an adenoviral vector able to carry out its effects (e.g., to deliver a therapeutic factor) only in certain cell types (e.g., cancer cells). Progress has been made with these limitations in mind by employing a number of different approaches. Some of these approaches have investigated inserting non-native ligands, or nucleic acid sequences encoding such ligands, into the MLTU, which theoretically allows for these adenoviral vectors to bind specific cell surface receptors to which it may not normally bind. For example, International (PCT) Patent Application WO 99/55365 describes an adenoviral vector comprising a first non-native nucleic acid sequence and a second non-native nucleic acid sequence which is different from the first non-native nucleic acid sequence. The first non-native nucleic acid sequences encodes, for example, a chimeric fiber protein that does not bind to the native adenoviral fiber receptor known as the Coxsackievirus-Adenovirus Receptor (CAR) but will bind to a receptor present on the surface of a target cell of interest. The fiber protein which binds to a receptor present on the surface of a target cell can be placed at any suitable location within the adenoviral genome, including 3′ of the L5 polyA site. This fiber protein also comprises splice acceptor elements and 3′ polyA signals.
Similarly, U.S. Pat. No. 5,543,328 describes an adenovirus comprising a fiber protein comprising a ligand, which is specific for a receptor located on a desired cell type. The ligand either replaces a portion of the fiber protein, or the adenovirus includes a fusion protein composed of the adenovirus fiber protein and the ligand. In certain embodiments, the ligand can be a tumor necrosis factor (TNF), transferrin, ApoB, α-2-macroglobulin, α-1 acid glycoprotein, mannose-containing peptide, sialyl-Lewis-X antigen-containing peptide, CD34 ligand, CD40 ligand, ICAM-1, M-CSF, circumsporozoite protein, VLA-4, LFA-1, NGF, HIV gp120, Class II MHC antigen, colony stimulating factor (CSF), insulin-like growth factor, or Interleukins 1 through 14. The adenovirus also can include a gene(s) encoding a therapeutic factor(s), which is typically inserted into the E1 or E3 region of the adenovirus.
In other approaches, a nucleic acid sequence encoding a therapeutic factor or ligand is not included in the adenoviral genome at all. For example, U.S. Pat. No. 5,677,178 (McCormick-Onyx Pharmaceuticals) describes the use of a certain type of replication-deficient adenovirus that replicates in certain abnormal (i.e., cancer) cells but does not replicate in normal (i.e., non-cancerous) cells. The conditionally replication-deficient adenovirus kills the abnormal cells through the expression of a replicative phenotype wherein the abnormal cells are lysed as part of the viral replication process. Thus, the adenovirus is replication-deficient in normal cells but is replication competent in abnormal cells.
To achieve this selective replication, the adenoviral vector described in the '178 patent substantially lacks an expressed viral oncoprotein capable of binding a functional p53 tumor suppressor gene product and/or a functional Rb tumor suppressor gene product. Abnormal cells lacking a functional p53 tumor suppressor gene product and/or a functional Rb tumor suppressor gene product can support the replication of the otherwise replication-deficient adenovirus substantially lacking an expressed viral oncoprotein capable of binding a functional p53 tumor suppressor gene product and/or functional Rb tumor suppressor gene product, respectively.
While previously-described vectors have been somewhat effective at delivering nucleic acids to target cells or treating certain disease states, a need remains to provide an adenoviral vector which more selectively carries out its activities in target cells, i.e., cells responsible for certain disease states, such that these adenoviral vectors can be formulated into therapeutic compositions and used in methods of treating these disease states. The invention provides such a vector, composition, and method. These and other advantages of the invention, as well as additional inventive features, will be apparent from the description of the invention provided herein.

Adenoviral vector with replication-dependent transgene expression


The invention is a control system for automatically tuning a stringed musical instrument with a capo installed, using an original calibration function or closed-loop tuning system for the instrument without the capo. The control system uses a capo scale factor which scales frequencies measured with the capo installed to what they would have been without a capo. The control system enables a musician to quickly tune an instrument after installing a capo, in a manner unlikely to be noticed by an audience.

Manually tuning a musical instrument can be a difficult and tedious process, usually requiring a considerable amount of time and skill. Although having an automatic tuning system is desirable for ease and convenience, as well as for accuracy, there is another important reason. Frequently, a musician will need to change the tuning of an instrument during a performance or an instrument will go out of tune during a performance. And, during this process, it may be necessary to compensate for a change in an instrument's characteristics. For example, during a performance with a guitar, a musician may install a capo between selections. A capo is a device for clamping all strings to a particular fret, thereby increasing the frequencies of all strings by a constant factor. Because of the time required, manually retuning an instrument during a performance is usually unacceptable. One common, although expensive and inconvenient, solution to this problem is to have properly tuned spare instruments available for such occasions. A much better solution is to have a system for automatically tuning an instrument within a length of time short enough to be unnoticed by an audience.
Many different types of automatic tuning systems have been devised. There are open-loop systems which drive a tuning actuator to a predetermined position for each desired frequency. These have the advantage of being able to change tuning, silently and therefore unnoticed, during a performance. However, they have the disadvantage of being only as accurate as the predicted relationship between the frequency of the tone produced by the instrument and the actuator position.
There are closed-loop systems which measure the frequency of the tone produced by the instrument, compare it to a desired value, and use the result of the comparison to control an actuator which tunes the instrument. This technique is accurate in that it directly controls the frequency of the instrument and is independent of other factors which affect frequency. However, it has the disadvantage that an audible tone must be produced while the instrument is being tuned; and that audible tone generally precludes tuning during a performance.
Some stringed instrument systems, because of interactions between strings, sequentially tune each string and then iterate to compensate for the interactions. Others tune selected strings, or all strings, simultaneously and then iterate. These techniques require producing a tone, taking a frequency measurement, estimating and executing an actuator movement, then taking a new frequency measurement and repeating the process until the frequency produced is sufficiently close to the desired frequency.
Other systems measure the tension of (actually, the force applied to) a string and compare the measured value with a desired value to produce an actuator control signal. Although the string tension method does not require a tone to be produced while tuning, it does require a known and stable relationship between string tension and frequency. Satisfying this relationship requirement is difficult because frequency also depends on string length and mass per unit length as well as other factors.
A typical stringed musical instrument has a semi-rigid structure which changes form slightly when string tensions in the instrument are adjusted during tuning. A change in form due to the adjustment of one string therefore affects the frequencies of the remaining strings. Temperature and humidity also affect the form, and the frequencies, of the instrument in more subtle ways.
A system which compensates for the effect of adjusting one string on the frequencies of the remaining strings, described in U.S. Pat. Nos. 4,803,908 and 4,909,126 to Skinn et al., which are incorporated by reference herein in their entirety, involves the use of a calibration function which relates the position of each actuator to the frequencies produced by all the instrument's strings. Creating the calibration function involves the measurement of frequencies at multiple positions of each actuator and, through regression techniques, relating the position of each actuator to not only the frequency of its own string but to the frequencies of the other strings as well. The use of regression techniques provides the advantage that a priori knowledge of the detailed characteristics of the instrument being tuned is not required. Also, the calibration function can be updated by recalibration as the instrument ages, or as environmental or other changes occur. Using a calibration function generated from the particular instrument being tuned permits open-loop, and therefore silent, tuning with accuracy comparable to that of closed-loop systems.
In all of the previously described open-loop systems, a calibration function relates a desired frequency to an actuator position. However, if such a system is calibrated without a capo and then a capo is installed, this relationship is destroyed and the system must be recalibrated for each position of the capo. It is therefore an object of this invention to provide for automatically tuning a stringed musical instrument after installing a capo without having to recalibrate the system.
In closed-loop systems wherein the measured frequency is compared to a desired frequency, installation of a capo shifts the measured frequency relative to the desired open string frequency and thereby skews the comparison. It is therefore a further object of this invention to provide for automatic closed-loop tuning of a string instrument after installing a capo.

Musical instrument self-tuning system with capo mode


A power controller in a communication system adjusts the transmitted power level using adaptive prediction of channel fading for maintaining the power level for improved communications by using an adaptive nonlinear predictor that explicitly takes into account the propagation delay and channel fading where the transmitted power is determined on the basis of the measurement of the received power levels over the individual diversity branches for providing communication through a fading channel with effective performance equivalent to that of a channel without any signal fading.

Existing closed loop power control algorithms in the Code Division Multiple Access (CDMA) and Universal Mobile Telephone System (UMTS) ignore the roundtrip delay incurred in the measurement of the received signal power. Such an assumption of zero round trip delay may be valid when the round trip delay is negligible in comparison to the inverse of the channel fading bandwidth. However, in the case of satellite channels such a condition is not satisfied. The round trip delay for geostationary satellites, for example, may be in the range of 250 msec to 500 msec, including any terrestrial delay, for a single hop or two-hop system. When compared to the inverse of the channel fading delay in the range of 1.0 to 10.0 sec, corresponding to the bandwidth in the range of 0.1 to 1.0 Hz, such a delay is not negligible. Hence, any power control algorithm based on such a zero delay assumption will not have satisfactory performance. Power control is necessary for frequency division multiple access (FDMA) and time division multiple access (TDMA) systems to control adjacent channel interference and mitigate unexpected interference caused by a near-far problem. In these systems, power control is needed to improve the quality of voice delivered to a user. However, in CDMA systems that are self-interfering, the capacity of the system depends directly on the power control and an accurate power control mechanism is needed for maximizing the number of users that can operate simultaneously in the system. Improved power control can also save the amount of transmitted power of the mobile station (MS), which increases the life of the battery.
In case of fading channels, diversity-combining techniques are generally employed to improve system performance. For example, in case of the CDMA systems, implicit diversity gain is exploited with the help of a rake receiver. In such a diversity system employing either an explicit or an implicit diversity, the power control in the terrestrial systems is based on the estimated power level at the diversity combiner output. In CDMA systems the power control on the reverse link, for example, is based on a combination of open loop control along with a closed loop correction implemented in the base station and the MS. For open loop probing on the access channel with closed loop correction inactive, the mobile station transmits the first probe signal at an output power level, defined by a mean output power in dBm is equal to k minus the mean receive input power in dBm plus 0.5, times, the nominal power in dB plus 0.5, times, the initial power in dB. The mean power is referred to a nominal CDMA channel bandwidth of 1.23 MHz and k, nominal power, and initial power are system parameters. The initial power parameter is any margin, positive or negative, above the required level. When the initial power is zero, then the nominal power is the correction to provide the correct received power at the base station. Essentially the power control, in both open loop and closed loop, is based on the assumption of identical channel gain on both the reverse and forward link, thus ignoring both the roundtrip propagation delay and the difference in the transmission frequency on the two links. Subsequent probes in an access probe sequence are sent at an increasing power level until a response is obtained from the base station. The initial transmitted power in the reverse traffic channel is at the power level given by the mean TX output power equation plus all the access probe corrections.
Uncontrolled differences in the forward and reverse channels, such as opposite fading that may result due to the frequency difference plus mismatches in the mobile station's transmit and receive chains result in the transmit power, which is different than the desired level. To reduce these residual errors, a close loop control is used wherein the mobile station measures the received Eb/N0 which is the bit energy to total noise power spectral density ratio, and transmits this information to the base station on the reverse link. The base station compares the performance measure against a threshold and based on the difference between the two sends a correction signal to the mobile station inserted in the forward data steam. The MS then corrects his transmit power on the basis of this correction information.
The closed loop correction in the CDMA systems ignores the round trip delay in comparison to the inverse of the channel fading bandwidth. For example, typically the fading bandwidth for the terrestrial cellular communication networks may be of the order of 50.0 Hz having a time constant of 20.0 msec compared to a round trip delay smaller than 0.1 msec for a cell radius of 10 Km and thus such assumption is satisfied. However, in the case of satellite channels with a roundtrip delay of 500 to 600 msec such an assumption is not valid even when the fading bandwidth is less than 1 Hz.
In the UMTS system, two loops for power control are involved. The inner loop is based on a bandwidth of about 1500 Hz with a period of 0.66 msec, measures the received signal to interference ratio and compares to the desired signal to interference ratio. The loop period is much higher compared to the roundtrip delay and thus the roundtrip delay is not too important in the loop design. This loop is similar to the closed loop in the CDMA system. An outer loop measures a service metric such as the frame error rate and adjusts the desire signal to interference ratio to account for any unmodeled uncertainties. The outer loop bandwidth is in the range of 10.0 to 100.0 Hz. Similar to the CDMA power control, a satisfactory operation of the UMTS system power control requires that the roundtrip delay be negligible compared to the channel fading bandwidth and the loop bandwidth. However, in the case of satellite channels such a condition is not satisfied. In case of the satellite channels, the round trip delay may vary between 250 to 550 msec, depending upon whether a single hop or two hop system is used, compared to 1.0 μsec to 100 μsec variation in UMTS system. When compared to a fading channel bandwidth of 0.1 to 1.0 Hz with a time constant of 1.0 to 10.0 seconds, the roundtrip delay is not negligible and hence the power control approach will not work satisfactorily. It is therefore necessary to take into account the roundtrip propagation delay explicitly in the design of the power control algorithm. A satisfactory operation of both the CDMA and the UMTS power control algorithm requires that the roundtrip delay be negligible compared to the channel fading bandwidth and the loop bandwidth. When compared to a fading channel bandwidth and time constant, the roundtrip delay is not negligible and hence the prior power control algorithms may not work satisfactorily. These and other disadvantages are solved or reduced using the invention.

Power controlled fading communication channel system


A steering system for an articulated vehicle having both steerable axle or wagon-wheel and articulation steering. A steering system is provided which is responsive to the position and rate of change of position of the articulated body portions with respect to each other, the position and rate of change of position of the steerable axle with respect to the body portion on which it is mounted, and operator steering direction input and the rate of change of that input, so as to provide transitions between the two types of steering which enhances operation of the vehicle. The steering system is also responsive to operator inputs as to the function for which the vehicle is being employed. The system also has the ability to dynamically adapt to the vehicle conditions, such as for adjusting transition between steering modes based upon past perfomance.

I. Field of the Invention
This invention relates to steering systems for articulated vehicles, and more particularly to a steering system which combines vehicle articulation with steerable movement of one axle of the vehicle.
II. Description of Related Art Including Information Disclosed Under Sections 1.97 and 1.98
It is highly desirable to provide a steering system for off-road type vehicles such as tractors, graders, or scrapers, to name a few which provides a small turning radius and which also provides readily responsive steering control on rough terrain. An articulated vehicle having four wheel drive has been found to provide a small turning radius, while an even smaller turning radius can be obtained if one of the axles of the articulated vehicle is steerable, typically called wagon-wheel type steering. Articulation of the vehicle is typically provided by mounting a pair of hydraulic cylinders between the two portions of the vehicle which are pivotally secured to each other. The cylinders are mounted on opposite sides of the pivot point, such that causing the extension of a first cylinder and the retraction of the second cylinder will cause the vehicle to turn in a first direction, while retraction of the first cylinder and extension of the second cylinder will cause the vehicle to turn in the opposite direction. The steerable axle, usually the front axle is provided by mounting a hydraulic cylinder between a pivotally mounted axle and the portion of the vehicle on which it is pivoted. To effectively control the steering of a vehicle having both articulation and steerable axle steering, it is desirable that a system be provided which effectively monitors the position and rate of change of position of the articulated body portions with respect to each other, the position and rate of change of position of the steerable axle with respect to the body portion on which it is mounted, and the position and rate of change of position of the steering control or controls manipulated by the vehicle operator, and utilizes inputs from the monitored conditions to control actuation of the hydraulic cylinders in response to an operator's input to provide a combination and timing of steering most responsive to the operator's input.
U.S. Pat. No. 4,771,851 entitled: Steering Control System for Articulated Vehicle, granted on Sep. 20, 1988 to Nystueun et al, assigned to the assignee of the subject application, sets forth the three position and rate of change of position inputs mentioned above, and discloses a steering control system which utilizes the three position and two of the rate of change of position inputs set forth above. The teaching of U.S. Pat. No. 4,771,851 are incorporated herein by reference.

Steering control system for articulated vehicle


An applicator including a liquid discharge head for discharging a treatment liquid in droplet form, and a discharge control device for controlling the discharge of droplets from the liquid discharge head. The discharge control device divides a surface of a member into a plurality of regions according to the shape of the surface, and controls the application quantity for each region.

Surfaces of plastic eyeglass lenses and other optical lenses are generally subjected to treatments for enhancing their performance and functions. Examples of such treatments include a primer coating, a hard coating, a dyeing treatment, and an antireflection treatment.
Primer coatings give an optical lens the function of enhancing the adhesion between the optical lens substrate and a hard coating film, and improve impact resistance. For plastic eyeglass lenses, techniques have widely been used in which a primer liquid is applied onto a surface of the plastic eyeglass lens and is then heated to cure the primer. An immersion method has mainly been used, conventionally, for this technique. In this immersion method, a plastic eyeglass lens is immersed in a primer liquid and allowed to stand while being held by a jig. The lens is then pulled out from the liquid to form a primer film.
Hard coatings give an optical lens many functions, such as enhancing the durability of an optical lens surface, the adhesion between the lens surface and a deposition film, and the stability of dyeing properties. For plastic eyeglass lenses, techniques have widely been used in which a hard coat liquid is applied onto a surface of a plastic eyeglass lens and is then heated to cure the hard coat liquid. An immersion method and an spin coating method have mainly been used for this technique, conventionally. In the immersion method, a plastic eyeglass lens is immersed in a hard coat liquid and allowed to stand while being held by a jig, and is then pulled out from the liquid to form a hard coat film. In the spin coating method, a hard coat liquid is discharged onto a surface of a plastic eyeglass lens and followed by rotating at a high speed. Thus, a hard coat film is formed.
A dyeing treatment is used particularly in manufacturing process of plastic eyeglass lenses for giving lenses fashionability. In this treatment, various colors are dyed, and an immersion method has conventionally been used. In the immersion method, a plastic eyeglass lens is immersed in hot water in which dye particles are dispersed with a surfactant and is then pulled up.
An antireflection treatment is used to prevent reflection at optical lens surfaces. Surface reflection reduces the transmittance of optical systems and increases light not involved in image formation, thus degrading image contrast. An antireflection treatment therefore, provides wearers with good visibility. Antireflection films have conventionally been formed in a single layer or a multilayer by vacuum deposition. A curable liquid having antireflection characteristics has recently been devised.
Application methods such as ink jetting or spraying have been devised for coating techniques in which a treatment liquid is applied onto only a desired region of optical lenses. In ink jetting and spraying methods, droplets of a treatment liquid are discharged from a small nozzle. An apparatus using ink jetting or spraying is reduced in size and can apply a treatment liquid at a low electric power. In addition, the liquid can be used with a high efficiency and production costs can be reduced. Furthermore, these methods are expected to reduce the amounts of used solvents and wastes, which promotes environmental protection.
Application, however, of the curable liquid having antireflection characteristics requires precise and uniform control of film thickness in order to ensure high performance. In an immersion method, the thickness of the coating film decreases at the upper side of the optical member and increases at the lower side due to gravity. Also, in the spin coating method, the thickness of a coating film decreases at the rotation center of the optical member and increases at the outer region due to centrifugal force.

Application method, applicator, optical member, and optical device


A turbine component such as a turbine blade has a cooling chamber that is tapered. The taper induces and maintains a helical swirl that improves the cooling efficiency of the cooling process and enables the turbine component to operate at higher temperatures.

Generally, it is necessary to provide internal cooling of turbine components. To achieve high performance it is desirable to utilise high turbine entry temperatures and so greater thermal efficiencies. Unfortunately, such high turbine entry temperatures are limited by inherent characteristics of the materials from which turbine blades and vanes are made. In such circumstances, internal cooling allows components made from available materials to operate at temperatures which are close to, or exceed natural melting temperatures.
Cooling systems for turbine vanes and blades generally comprise providing a feed of cool air, taken from the compressor system in a jet engine, and feeding that cool air to the turbine blades through internal passages and chambers in order to effect cooling by a combination of internal convection and external film cooling.


A high-speed bipolar transistor is provided which is improved in the effect of heat radiation without increasing the substrate capacitance. The heat radiation connection between a base region and a silicon substrate includes a p+ extrinsic base polysilicon electrode and a polysilicon layer buried in an isolation groove with a very thin silicon dioxide side wall. Accordingly, the heat generated at the base is radiated through this path to the silicon substrate. Further, the film thickness of the silicon dioxide on the inner wall of the isolation groove is sufficiently increased compared with previous structures to prevent an increase in the substrate capacitance. Consequently, there can be obtained a bipolar transistor which operates at high speed, and is improved in the effect of heat radiation without increasing the substrate capacitance.

1. Field of the Invention
The present invention relates to a semiconductor device using an SOI (Silicon On Insulator) substrate. More particularly, it relates to a high speed bipolar semiconductor device, and a drive circuit made up of the semiconductor devices.
2. Description of the Related Art
A bipolar transistor will be described as a prior-art example of a semiconductor device of an SOI structure. An example of this kind of bipolar transistor is disclosed in xe2x80x9cA 6-xcexcm2 bipolar transistor using 0.25-xcexcm process technology for high-speed applicationsxe2x80x9d (Bipolar/BiCMOS Circuits and Technology Meeting 1998 proceedings).
FIG. 2 shows a cross sectional view of the bipolar transistor described in the prior-art example.
In FIG. 2, a reference numeral 1 denotes a silicon substrate, 2 a buried silicon dioxide, 3 a silicon layer, 4 an n+ buried layer, 5 an nxe2x88x92 silicon epitaxial layer, 6 a field oxide, 7 an n+ collector contact layer, 11 an isolation oxide, 14 a p+ extrinsic base polysilicon electrode, 15, 18, and 22 silicon dioxides, 16 an intrinsic base layer, 17 a graft base, 19 an n+ polysilicon sidewall, 20 an n+ polysilicon emitter, 21 a single crystal silicon emitter, and 23, 24, 25 metal electrodes.
Further, as a second prior-art example, a part of the configuration disclosed in JP-A No. 86298/1995 is shown in FIG. 3. Some reference numerals are used in common with FIG. 2, and as other reference numerals, 12 denotes a polysilicon, and 30 a silicon dioxide.
In general, a semiconductor device generates heat during operation. Particularly, a bipolar transistor generates a large amount of heat, and radiates the heat to a silicon substrate. In recent years, an SOI (Silicon On Insulator) substrate with an insulating film buried therein has been used in place of a silicon bulk substrate aiming at reducing the substrate capacitance and merging complementary MOS therewith. The prior-art example as shown in FIG. 2 is a preferable example thereof. The thermal conductivity of the buried silicon dioxide 2 is about {fraction (1/100)} as compared with silicon. Therefore, the generated heat is less likely to be radiated to the substrate as compared with the silicon bulk substrate, resulting in an increase in temperature in the transistor. Consequently, the change in the electrical characteristics of the transistor becomes remarkable.
Particularly, a hetero bipolar transistor using silicon-germanium as a base is reduced in current gain with an increase in temperature. This indicates the phenomenon that the electrical characteristics of the transistor differ according to the difference in density of the transistor arrangement, and the conditions of use. For this reason, a problem occurs that it is impossible to attain the performances as designed in a designed circuit. Further, the transistor is required to be used at high current for high-speed operation. Accordingly, the high-speed operation of the transistor is restricted in order to prevent the heat generation due to a current. Such a phenomenon holds true for not only the hetero bipolar transistor, but also semiconductor devices of an SOI structure such as a bipolar transistor using an SOI, a high-power MOS field effect transistor of an SOI structure, and a resistor used at a high current density.
As a means for solving the problem of heat radiation, for the bipolar transistor disclosed in the second prior-art example shown in FIG. 3, an isolation oxide 11 and a polysilicon 12 are buried in an isolation groove penetrating from a silicon substrate 1 to a buried silicon dioxide 2 and a silicon layer 3. As a result, the generated heat flows through the isolation oxide 11 to the polysilicon 12, and is radiated to the silicon substrate 1. In this case, the isolation oxide 11 is required to be reduced in film thickness in order to enhance the effect of heat radiation. However, if the isolation oxide 11 is reduced in thickness, the capacitance arising at the isolation groove portion of the substrate capacitance increases. Incidentally, the structure of the second prior-art example is a part of the one described in the JP-A No. 86298/1995. With this structure, heat radiation is carried out not through the silicon substrate, but at a heat radiation electrode through the groove in which a polysilicon is buried.
It is generally an object of the present invention to enhance the effect of heat radiation in a semiconductor device. In particular, it is an object to provide a bipolar semiconductor device which has been improved in effect of heat radiation without increasing the substrate capacitance, and operates at high speed. Further, it is another object of the present invention to provide an optical transmission system using the semiconductor devices.
The general outline of the present invention disclosed by this application will be described briefly below. Namely, a semiconductor device in accordance with the present invention is characterized in that the heat generated within the semiconductor device is led by a single crystal silicon or polysilicon layer, and radiated from the single crystal silicon or polysilicon to the silicon substrate through another single crystal silicon or polysilicon connected to the silicon substrate.
Below, a typical example of the present invention will be described briefly.
A bipolar transistor is characterized by having such a structure that an extrinsic single crystal silicon, or polysilicon base electrode is in contact with a single crystal silicon or polysilicon buried in an isolation groove, or an insulating film sufficiently thinner than the thickness of a field oxide is inserted in the interface therebetween. As a result, the heat generated in an intrinsic area passes through the extrinsic single crystal silicon or polysilicon base electrode having a thermal conductivity which is about 100 times that of a silicon dioxide, and radiated through the single crystal silicon or polysilicon in the isolation groove to the silicon substrate.
If this effect is combined with the effect of heat radiation through an insulating film on the inner sidewall of the isolation groove in the prior art, when the area of the emitter is about 0.2xc3x971 xcexcm2, and the thickness of the silicon dioxide on the inner sidewall of the isolation groove is 0.2 xcexcm, heat radiation is two times or more effective than the prior-art example. The effect becomes noticeable for a transistor formed with a more advanced submicron patterning. In other words, the effect becomes noticeable due to the following fact: the distance between the intrinsic area and the isolation groove is reduced, resulting in a decreased thermal resistance at the extrinsic base electrode. Further, since the surface area of the sidewall of the isolation groove is reduced, the thermal conductivity of heat passing through the sidewall is reduced. As a result, the thermal resistance at this portion is increased. Accordingly, the effect of heat radiation due to the structure of this application is further improved.
By reducing the thickness of the silicon dioxide buried in the isolation groove, it is also possible to improve the effect of heat radiation with the prior-art structure. However, when the thickness is reduced, the substrate capacitance arising through the silicon dioxide between the collector area and the silicon substrate is increased. On the other hand, with the structure of this application, silicon in the isolation groove is used as the path for heat radiation. Therefore, even if the thickness of the silicon dioxide buried in the isolation groove is increased, the reduction in the effect of heat radiation is xc2xd or less as compared with the prior-art structure. Accordingly, it is possible to sufficiently ensure the effect of heat radiation while inhibiting the increase in the substrate capacitance.
When the extrinsic base electrode and the silicon in the isolation groove are in direct contact with each other, the impurities in the extrinsic base electrode diffuse into the silicon in the isolation groove. However, the diffusion depth of the impurities due to the thermal budget in a normal high-performance bipolar transistor formation process is about 0.2 xcexcm even when a polysilicon is used, and thus it will not be deeper than the field oxide thickness. When a single crystal silicon is used, the diffusion depth is shallower as compared with the polysilicon. The amount of increase in base-collector parasitic capacitance arising due to the diffusion of impurities is about 3% of the total base-collector parasitic capacitance, which is a negligible value.
If a consideration is given to the insulating property between the extrinsic base electrode and the silicon substrate, the resistance value of the silicon in the isolation groove is required to be 1 Mxcexa9 or more. In general, the resistivity is 104 xcexa9xc2x7cm or more for an undoped polysilicon. Whereas, it may be 103 xcexa9xc2x7cm or more even for a single crystal silicon. In this case, the resistance value between the extrinsic base electrode and the silicon substrate exhibits 1 Mxcexa9 or more even when a single crystal silicon is used. Therefore, the resistivity is required to be 103 xcexa9xc2x7cm or more from the viewpoint of the insulating property of this portion in either case where the silicon in the isolation groove is single crystalline or polycrystalline.
When the thermal processing in the transistor formation step is more often performed than normal, the impurities in the extrinsic base electrode diffusing into the silicon in the isolation groove increase in amount. In such a case, a thin insulating film becomes required to be inserted between the extrinsic base electrode and the silicon in the isolation groove. In this case, the effect of heat radiation varies according to the thickness of the insulating film. If the insulating film thickness is 10 nm, the effect of heat radiation is reduced by as much as twice that of a prior-art structure.
The current density passing through a transistor is expected to increase up to twice thereof in the future, and hence the effect of heat radiation is required to be twice the current effect of heat radiation. Therefore, it is considered desirable that the insulating film thickness is 10 nm or less.
For an MOS field effect transistor, heat is radiated from a single crystal silicon or polysilicon layer formed on a source or drain to the single crystal silicon or polysilicon in the isolation groove.
For a resistance element formed with a polysilicon, it is also possible to radiate heat directly from the resistor to the silicon in the isolation groove.
The same effects as illustrated in the description on the bipolar transistor are also exerted in the cases of the MOS field effect transistor and the resistor.
Other and further objects, features and advantages of the invention will appear more fully from the following description.

Semiconductor device and drive circuit using the semiconductor devices


A fixation device includes a member defining at least two openings, and a suture tied to the member by passing the suture through the at least two openings in the member to form two suture loops through which ends of the suture pass. The two suture loops are interconnected. A method of securing a tissue graft includes providing the fixation member, attaching the suture to a tissue graft, and adjusting the length of the suture between the fixation member and the tissue graft by pulling the suture.

An anterior cruciate ligament (ACL) that has ruptured and is non-repairable is generally replaced arthroscopically by a tissue graft. The tissue graft can be harvested from a portion of a patellar tendon having so called "bone blocks" at each end, and from the semitendonosis and gracilis. Alternatively, the tissue graft can be formed from synthetic materials or from a combination of synthetic and natural materials.

This patent is subject to a terminal disclaimer.


A method and device for enabling oscillating drive of at least one tooth cleaning element in a tooth cleaning device which includes a drive unit and motion transmitters acting between the drive unit and the at least one tooth cleaning element. A rotary motion, derived from the rotary motion of the drive unit, is converted and one of the motion transmitters in a vicinity of at least one tooth cleaning element into a cyclic linear motion directed at an angle to an axis of the rotary motion of the drive unit and transmitted to the cleaning element.

In, for example, DE-27 15 414 and U.S. Pat. No. 3,978,852, electric toothbrush arrangements are provided wherein a toothbrush includes a drive shaft driven in a drive unit, for example, a handle housing. The rotary motion of the drive shaft is converted to a cyclic linear motion in the housing itself in order to move a toothbrush head mounted in the handle housing back and forth as a unit.
In German Utility Model DE-G 89 11 427.2 an electric toothbrush is proposed in which a drive shaft projects through the head of the brush and moves a toothbrush mounted endwise back and forth with a cyclic linear motion derived from the shaft. The rotary axis of the cyclic linear motion runs parallel to the rotational axis of the drive shaft.
An electric toothbrush according to European Patent Application No. 0 173 114, with the present patent application being a continuation and improvement on said European patent application.
As in the above-mentioned European patent application, it is important that the various tooth surfaces be cleaned equally well by a cleaning device. Therefore it is important that, in particular the inner, that is, facing the oral cavity, as well as the gums, and the outer tooth surfaces, that is the tooth surfaces facing the cheeks of the user, and the gums themselves, all be cleaned equally, as well as possible. It is also important that the best possible local cleaning pressure be provided at all points to be cleaned. Finally, it is important that the cleaning elements perform optimum movements, that is, movement directed from the gum outward and toward the crown of the tooth as coaxially as possible with respect to the tooth, and not in the opposite direction.
In the above-mentioned European Patent Application No. 0 173 114, which is an integral component of the present application, the method for cleaning the teeth by an electric toothbrush is especially important for the present application, which states that it is important that cleaning be performed simultaneously on at least two sides of the tooth. The method defined according to European Patent Application No. 0 173 114 and important to the invention as well as the device features of the electric toothbrush thus defined, in combination with the features of the invention defined below for the present invention, constitute features of the present patent application that are essential to the invention.
In EP-A-0 173 114, the various motions in a electric toothbrush defined according to the invention are executed primarily with pneumatically or hydraulically operable drive elements. Although the hydraulically or pneumatically operable drive elements have proven themselves, one goal of the present invention is to refine the drive mechanism further and to simplify it in order firstly to increase further the operational safety of electric toothbrushes, to reduce manufacturing costs, and finally to permit a smaller design for the cleaning heads.

Method for driving a tooth-cleaning element


This specification discloses a VCSEL (Vertical-Cavity Surface-Emitting Laser) device with single-mode output and optionally single polarization output. This device is given by lateral mode confinement by the PBG (Photonic Band-Gap) effect by shallow etching in a partial VCSEL top mirror. The PBG area encircles a MS-region (Mode-Shaping region), which is characterized by large longitudinal mode losses. The MS-region encircles the LA-region (Light Aperture region), which is characterised by low longitudinal mode losses. The MS-region does not contribute to the lateral mode-confinement to the LA-aperture, and the lateral modes confined by the PBG area. The VCSEL is thus optimized for single fundamental mode operation.

Vertical-cavity surface-emitting lasers (VCSELs) have several advantages such as low-threshold, small size, on-wafer testability and high fiber coupling-efficiency. Single-mode VCSELs would be especially useful for applications such as data—(emission wavelength of λ=850 nm) and telecommunication (λ=1.3-1.7 μm), if sufficient high single-mode output powers (5-20 mW) could be extracted from a VCSEL.
VCSELs emit radiation perpendicular to the semiconductor substrate plane, either from the top or the bottom of the device structure. A VCSEL is a surface-emitting laser having mirrors disposed parallel to the substrate surfaces that form and enclose an optical cavity between them. VCSELs usually have a substrate upon which a first mirror stack and second mirror stack are disposed, with an active region between them comprising either quantum wells or quantum dots. Since the gain per pass in a VCSEL is much lower than in an edge-emitting laser a higher reflectivity of the mirrors is required. For this reason, the mirror stacks in a VCSEL typically comprise a plurality of Distributed Bragg Reflector (DBR) mirrors, which may have a reflectivity of 99% or higher. An electrical contact is usually positioned on the second mirror stack, and another contact is provided at the opposite end in contact with the substrate. When an electrical current is injected to flow between the two contacts, lasing is induced from the active region and emits through either the top or bottom surface of the VCSEL. A schematic drawing of a VCSEL structure is shown in FIG. 1.
FIG. 1 illustrates an example of a VCSEL 100 according to the prior art. The core of the VCSEL 100 is an active region 110 that includes quantum wells 112. In FIG. 1, the active region 110 is bound by the upper DBR layers 108 and lower DBR layers 114. One of the DBR layers includes n-type semiconductor material and the other p-type semiconductor materials. DBR layers are formed by alternating layers of material whose refractive index varies. Each individual DBR layer typically has a thickness of approximately λ/4. These alternating layers are often formed from semiconductor materials or dielectric materials.
Light is reflected at the junction of the DBR layers, but in order to achieve the high reflectivity required by VCSELs, many layers must be formed or grown. Thus, the DBR layers 108 and 114 form mirror layers that reflect light through the active region 110. The light aperture of the VCSEL 100 through which light is emitted is typically formed by selective oxidation of one or some of the DBR layers (region 106) or ion implantation to form an aperture 107 through which light can escape and through which electrical current can flow. Finally, the VCSEL 100 also includes a substrate 116 and metal contacts 104 and 118.
The composition of the active region 110 is often related to the wavelengths that are generated by the VCSEL 100 and are typically formed from some combination of GaAs or AlGaAs. The present invention is not limited to these materials. For example GaNAs, InGaNAs, InGaAs, GaInNAs, InGaAsP, and InGaP are often used in quantum wells that emit wavelengths of 650, 780, 850, 980, 1300 and 1550 nm. The composition of the quantum well or the bulk active region has an impact on the band gap, which is related to the wavelengths or modes generated by the VCSEL 100.
The mode confinement in conventional optical waveguides is achieved by having a core with a high refractive index surrounded by a cladding with a lower refractive index. This results in a waveguide based on the principle of total internal reflection. In an optical resonator, such as a VCSEL, a cavity resonance-wavelength shift corresponds to an effective index step in a conventional optical waveguide structure, Δλ/λ=Δn/n, as pointed out by Hadley [G. R. Hadley, "Effective index model for vertical-cavity surface-emitting lasers," Optics Letters Vol. 20, No. 13, p 1483 (1995)]. As a result, lateral mode confinement in a VCSEL can be accomplished by having a core with a long cavity resonance-wavelength surrounded by a cladding region with a short cavity resonance-wavelength. The lateral mode confinement in such a VCSEL is analogous to the lateral mode-confinement in a conventional index-guided fiber.
In contrast, micro-structured fibers having a rich topology in the refractive index of the cladding, typically air-holes in a silica cladding, enable lateral mode-confinement to a central, low-index core of the fiber (for example a large air-hole). These fibers are denoted Photonic Band-Gap (PBG) fibers. The PBG fibers guide light by an effect that may be seen as an optical analogue to the electronic bandgaps of semiconductors. The light aperture of a PBG fiber, also denoted the PBG-defect, has an effective index which is lower than the surrounding cladding region. A fiber where the index of the core is lower than the cladding is denoted an anti-guide, and would not confine any lateral modes in the absence of the photonic bandgap effect.
Lateral mode-confinement by the PBG effect in a VCSEL can be implemented by a core (light aperture) surrounded by a cladding region with a rich topology with variations of the cavity resonance-wavelength. Etching in the top of a VCSEL DBR top-mirror results in a shift of the cavity resonance-wavelength. Local etching of a VCSEL top mirror is thus an efficient method to locally modify the cavity resonance wavelength and to implement lateral mode confinement by the PBG effect as described in the previous patent application WO 02/073753.
Let us for clarity give a more in-depth explanation of the relation of the index step in an optical fiber with the cavity resonance condition in an optical resonator like a VCSEL.
An optical resonator can be realized using two plane-parallel mirrors separated with a spacer of a thickness L and refractive index n. Without loss of generality we can assume that the plane mirrors extend in the xy-plane. An optical resonator is characterized with a set of resonance wavelengths λm=2 Ln/m, m=1, 2, 3, . . . Light with these wavelengths will at normal incidence experience increased transmission through the resonator.
The laser cavity may support a plurality of lateral modes for the generated light. In the present application, a lateral electromagnetic mode can be regarded as a distribution of plane waves, with wave-vectors {right arrow over (k)} describing the propagation of the electromagnetic field. Any of the wave-vectors {right arrow over (k)} may be projected onto a plane which is normal to the extension of the cavity, such as a plane parallel to a mirror. The projection of {right arrow over (k)} onto such a plane will be designated the lateral component {right arrow over (k)}∥ of the wave-vector {right arrow over (k)}, the term lateral refer to the extent of the cavity rather than to {right arrow over (k)}. The length of {right arrow over (k)} is
      k    =                  2                π                                                            n          _                    λ        ,where n is the effective longitudinal index of refraction. The lateral component of {right arrow over (k)} is thus useful for defining a lateral-wavelength:
            λ              =                  2                π                                                            n          _                                              k                                        ,the propagation constant in the z-direction is accordingly
            k      z        =                  2                π                                                            n          _                            λ        z              ,where k=√{square root over (|kz|2+|k∥|2)}.
Let us in a first example assume a VCSEL resonator where the core of the VCSEL has a short cavity resonance-wavelength λcore, while the cladding region has a longer cavity resonance-wavelength λclad. The lengths of the resonant wave-vectors of the two regions are:
      k          z      ,      core        =                              2                    π                                                                          n            _                                    λ          core                    >              k                  z          ,          clad                      =                            2                    π                                                                          n            _                                    λ          clad                    .      We first consider an electromagnetic field resonant with the core resonator: λ=λcore and
      k    =                  2                π                                                            n          _                            λ        core              ,hence the field has a wave-vector {right arrow over (k)}={right arrow over (k)}z,core, and propagates solely in the direction of the z-axis in the core resonator. However, in the cladding resonator we find that since {right arrow over (k)} is conserved, {right arrow over (k)}={right arrow over (k)}z,clad+{right arrow over (k)}∥,clad, where k∥,clad2=k2−kz,clad2 or
      k                        ,        clad              2    =                    (                              2                        π                                                                                n              _                                            λ            core                          )            2        -                            (                                    2                            π                                                                                n                _                                                    λ              clad                                )                2            .      Since λcore<λclad the value of k∥,clad is real and the field can freely propagate in the cladding region. In this case the core region is an anti-guide. Now in the opposite case λcore>λclad the value of k∥,clad would be complex corresponding to an evanescent field in the cladding region. In this case the core would be a guide for the optical field.
The discussed example shows how the cavity resonance wavelength determines the guide- or anti-guide properties of a VCSEL. Furthermore, the discussed example gives a good physical picture of what is meant by lateral-wavelength (λ∥), which will be extensively used when discussing the implementation of lateral mode-confinement by the photonic band-gap effect in a VCSEL.
For PBG waveguides, the physical dimensions of the PBG micro/nano-structuring is related to the lateral wavelength (λ∥) and is expected to be quite large since λ∥ is expected to be much larger than longitudinal wavelength λz as well as the free-space wavelength. The realization of the PBG effect is thus not expected to be limited by the present limits of semiconductor processing techniques.
The cavity resonance wavelength of a vertical-cavity surface-emitting laser can be changed by a variation of the thickness of one or several layers within the Bragg mirror of the VCSEL. A change in the cavity resonance wavelength can be observed as a periodic function of etch depth, when etching through a VCSEL mirror.
As described previously, the lateral mode confinement of a waveguide (VCSEL) depends on the index (cavity resonance wavelength) difference. Local etching of a VCSEL top mirror can be used to form a weak index guide or a weak anti-guide, if the cavity resonance wavelength is longer or shorter for the core part of the VCSEL compared to the cladding region, respectively. The reflectivity of the VCSEL top or bottom mirror is changed when the mirror is thinned down by etching. However, the reflectivity is not decreasing monotonically as a function of etch depth, but is, similarly to the cavity resonance wavelength, a periodic function of the etch depth. The periodicity is given by the longitudinal quarter wavelength within the Bragg mirror material. The maximum and minimum reflectivity of this periodic mirror reflectivity is of course decreasing for increasing etch depth as a result of the decreasing number of DBR mirror layer pairs.
FIG. 2 illustrates an example of a vertical cavity surface emitting laser 200 where a photonic micro/nano-structure 210 is added in the top of the DBR mirror layers 202, see e.g. WO 02/073753. The active region 204 is bound by the upper DBR layers 202 and lower DBR mirror layers 206. The photonic micro/nano-structure 210 is formed by shallow or deep etched holes 212 from the top of the upper DBR mirror for lateral mode control. The photonic micro/nano-structure defines a light aperture region 214 through which light is emitted. The lateral current confinement is typically formed by selective oxidation of one or more layers within the DBR structure or ion implantation. The current aperture is typically larger than the light aperture 214 of the photonic micro/nano-structure. The lateral light and current aperture are thus decoupled for this kind of VCSEL 200. The lateral optical modes are thus optimised independently of the electrical lateral current aperture.
The cavity resonance wavelength shift is relatively small when etching in a complete semiconductor top-mirror in case of shallow etches (just a few DBR mirror pairs). The cavity resonance wavelength is changed by several nanometers, when deep holes (penetrating several periods) are etched into one of the DBR mirrors of the VCSEL as in region 210 of FIG. 2. In this case the longitudinal reflectivity of the etched areas 212 is significantly reduced as a result of the reduced number of DBR mirror layer pairs. The reduced DBR reflectivity will, together with the achieved cavity resonance wavelength shifts, determine the lateral modes confined to the light aperture 214. In some cases, the laterally changing loss will dominate the mode confinement in a process similar to the gain-guiding mechanism well known from broad area edge emitting lasers. Furthermore, the implementation of the PBG effect requires a relatively high cavity resonance wavelength shift between etched and un-etched areas.
The actual value of the cavity resonance wavelength as function of etch depth is dependent on the position of etches within the DBR. A large shift of the cavity resonance wavelength is possible by shallow etching, when the PBG structures are close to the active region of the VCSEL and embedded in the DBR top mirror. The maximum cavity resonance wavelength-shift decreases (for the same etch depth), as the position of the PBG structures are closer to the top of the DBR mirror. Hence, to introduce the necessary high cavity resonance wavelength shift between etched and un-etched areas, shallow holes 312 are etched within one of the VCSEL DBRs as shown in FIG. 3 instead of on top of the DBR. The cavity resonance wavelength shifts are very large (several tens of nano-meters) for etch depths of less than 200 nm, and the mirror reflectivity (photon-lifetime of the VCSEL cavity) is much less affected by this approach.
FIG. 3 illustrates an example of a vertical cavity surface emitting laser 300 where a photonic micro/nano-structure 318 is embedded in the top DBR mirror layers 302, see e.g. WO 02/073753. The shallow etching of holes 312 is done in a partial top mirror, which reflectivity is insufficient for lasing of the VCSEL. The top DBR mirror reflectivity necessary for reaching lasing is for example obtained by a re-growth processing step or deposition of a dielectric top-mirror. The full DBR top mirror 302 consists of three different layers, the first un-etched partial top-mirror region 316. The lateral micro/nano-structuring 310 in the partial top-mirror layer 318 is made by shallow etching of holes. The top-mirror 320 is deposited or re-grown after definition of the lateral micro/nano-structuring 310.
The partial DBR top-mirror layer 316 may be omitted or replaced with a spacer layer. Furthermore, the micro/nano-structured layer 318 may be formed by shallow etching in either a partial semiconductor DBR top-mirror layer or a dielectric DBR top-mirror layer or a combination of both semiconductor and dielectric partial DBR top-mirror layers. The light-aperture region 314 defines the PBG-defect to which region the light is confined. The cavity resonance wavelength of the LA-region 314 is typically at least shorter or equal to the surrounding region 312 and 313. The cavity resonance wavelength depends on the etch depth and the difference in cavity resonance wavelengths of region 312, 313 and 314 has been visualized by different etch depths. Finally, the VCSEL 300 also includes an active region 304, a lower DBR bottom-mirror 306 and substrate 308.
The patent U.S. Pat. No. 6,396,865 by L. J. Mawst and D. Zhou discloses a vertical-cavity surface-emitting laser, where the lateral mode confinement is implemented with a single or two anti-resonant reflecting optical waveguide (ARROW) rings. The ring width is an odd number of lateral quarter wavelengths.
The ARROW method using only a single ring was also published in: D. Zhou and L. J. Mawst, "Simplified-antiresonant reflecting optical waveguide-type vertical surface-emitting lasers", Applied Physics Letters Vol. 76, No. 13, p. 1659 (2000). The ARROW method uses one or two anti-resonant reflecting rings to reduce the lateral wave-guiding losses resulting from the poor mode confinement of a central anti-guide. The anti-guide promotes single-mode operation, while the anti-resonant reflecting ring(s) reduce the lateral radiation losses for the fundamental mode and higher order modes. The threshold current of a VCSEL using only an anti-guide is thus reduced when implementing the ARROW mode confining ring(s). The lateral radiation losses for the higher order modes are also reduced in the ARROW design, but are still significantly higher than for the fundamental mode.
In "Suppression of Polarization Switching on Birefringent Antiresonant Reflecting Optical Waveguide Vertical-Cavity Surface-Emitting Lasers," IEEE Photonics Technology Letters, Vol. 16, No. 3, p. 711 (2004) by N. S. Chen, S. F. Yu, and C. W. Tee, the one and two anti-resonant ring VCSEL designs are shown to have improved single polarization mode stability, when the ring next to the anti-guide (light aperture) is slightly broader than an odd number of lateral quarter wavelengths. The ring width increases up to approximately λ/3 for optimum polarization stability, the ring is circular and does not introduce any asymmetry in the lateral reflection coefficients for the two orthogonal polarization states.
These prior single-mode designs are based on a method, where the anti-guide (light aperture) is enclosed by an area (ARROW ring(s)) giving an increased confinement to the anti-guide, which reduces the lateral radiation losses of both the fundamental and higher order modes. The addition of these rings result in a decreased threshold current compared to an anti-guide VCSEL structure due to the reduced radiation losses. However, lateral mode confinement by one or two reflector-rings decreases the single mode operating regime for larger light aperture (anti-guide) size, since both the fundamental and higher order lateral modes are more strongly confined for these ARROW type VCSEL designs.
The physical implementations of these prior single-mode designs have been using epitaxial re-growth to implement the arrow rings. This is a costly production method and it reduces the yield significantly in the processing of devices. The designs furthermore use ion-implantation to confine current in the lateral direction. This has the advantage of restricting flow of current without introducing optical confinement. However, the method has to a large degree been abandoned by the industry due to large process variations and instabilities. Instead, oxide confinement is dominating present implementations of VCSELs resulting in high yield and excellent reliability. The introduction of oxide confinement in the arrow type single mode VCSELs is difficult and not yet demonstrated. The presence of the oxide layer will disturb the function of the arrow rings due to the lateral confinement of the oxide aperture itself.
U.S. Pat. No. 6,185,241 discloses a microcavity laser in which an annular metal layer suppresses higher-order modes by introducing an absorbing aperture. A typical value for the diameter of the annular metal layer is 5 um, and besides introducing a mode-dependent loss, the annular metal layer also defines the aperture of the laser.
U.S. Pat. No. 5,838,715 discloses a VCSEL comprising a loss-determining element that progressively increases an optical loss of the VCSEL's optical cavity with increasing lateral distance from the optical axis (the axis parallel to the substrate normal). An annular metal layer provides a mode-dependent loss and also defines the light aperture of the laser. The loss-determining element is typically a curved section that provides a lens effect.
U.S. Pat. No. 5,432,812 discloses use of a micro-cavity semiconductor laser having a three-dimensional optical reflector that covers a double-heterostructure section for controlling the spontaneous emission along various directions and for increasing the coupling ratio of spontaneous emission with a specific laser mode to thereby decrease the threshold current of the laser. Embodiments of lasers according to the invention disclosed in U.S. Pat. No. 5,432,812 may have a PBG-structure similar to those illustrated by 210 in FIG. 2 or region 310 in FIG. 3. A laser according to U.S. Pat. No. 5,432,812 has an optical reflector covering its double heterostructure section, which is a section that surrounds the active portion of the laser.


A fluid-filled cylindrical vibration damping device comprising: an elastic body connecting an inner shaft member and an outer sleeve member; a non-compressible fluid-sealing region formed between the inner shaft member and the outer sleeve member; a stop rubber member disposed within the fluid-sealing region and projecting form one of the inner shaft member and the outer sleeve member toward an other of the inner shaft member and the outer sleeve member; and a rigid restricting member bonded to a projecting end portion of the stop rubber member. The stop rubber member extends to a front surface of the rigid restricting member so as to form an abutment rubber projecting from an outer peripheral portion of the front surface so that the projecting end portion of the stop rubber member is brought into abutting contact with the other of the inner shaft member and the outer sleeve member with the abutment rubber.

1. Field of the Invention
The present invention relates generally to a cylindrical vibration damping device usable as suspension bushings, engine mounts, body mounts, differential mounts, sub-frame mounts and the like, and more particularly to a cylindrical vibration damping device of fluid-filled type, which is capable of exhibiting vibration damping effects on the basis of flow action of non-compressible fluid sealed in a fluid sealing region enclosed therein, and which includes a stop rubber member installed within the fluid sealing region.
2. Description of the Related Art
A fluid filled cylindrical vibration damping device is known as one type of vibration damping couplings or mounts interposed between two components connected together in a vibration-isolating fashion. Disclosed in Citation 1 or 2 (see a document list in paragraph 0008) is an example of such a fluid-filled cylindrical vibration-damping device including an elastic rubber member elastically connecting a metallic inner shaft member, and a metallic outer sleeve member disposed about the inner shaft member, and a fluid sealing region defined between the inner shaft member and the outer sleeve member. When subjected to vibration applied thereto, the known fluid-filled cylindrical vibration-damping device is able to provide a vibration damping effect on the basis of flow action of non-compressible fluid sealed in the sealing region.
In the above-described known cylindrical vibration damping device, a stopper mechanism utilizing a stop rubber member, protruding from one of the inner shaft member and the outer sleeve member toward the other, is suitably installed in order to limit an amount of elastic deformation of the rubber elastic body in a cushion like manner during input of an excess vibrational load in its axial direction. Typically, the stop rubber member is disposed within the fluid-sealing region, as shown in the above-mentioned Citations 1 and 2, in order to avoid enlargement of the device itself.
However, the conventional stopper mechanism suffers from the inherent problem. Namely, in the event where the stopper rubber member comes into abutting contact at its projecting end portion with the inner shaft member or the outer sleeve member as a result of exertion of an excess external force thereon, a so-called "stick-slip" motion in boundary lubrication may occur in association with the elastic deformation of the stop rubber member. Accordingly, the conventional stop mechanism is prone to induce noises due to friction of the stop rubber member associated with its elastic deformation. Where the stop rubber member is installed in the fluid-sealing region, especially, the induced noises may be transmitted to the rubber elastic body via the sealed non-compressible fluid, and then amplified, so that the generation of noises becomes a significant problem. If a grease or other lubricant is applied to an abutting surface of the stop rubber member to minimize or reduce the noises, the grease is readily dispersed into the non-compressible fluid, making it difficult for the conventional stopper mechanism to provide effective noise damping performance.
To cope with this problem, there has been proposed another stopper mechanism wherein a rigid stop block is employed instead of the stop rubber member, and only a thin stop rubber layer is only formed secured on the a top abutting surface of the stop block, as disclosed in Citations 3 and 4, for example. Since the rigid stop block of the aforesaid structure permits a small amount of elastic deformation thereof upon abutting contact with the inner shaft or outer sleeve member, stick-slip motion at the abutting surface of the rigid stop block is prevented, making it possible to eliminate or minimize generation of the noises.
In the proposed stopper mechanism employing the rigid stop block, however, abutting noises and impact created as a result of abutting contact of the rigid stop block against the inner shaft or outer sleeve member cannot be absorbed only by means of the thin stop rubber layer. Therefore, the proposed stopper mechanism is very likely to suffer from the problem of abutting noises and impact induced upon abutting contact of the rigid stop block against the member. Moreover, the abutting contact of the rigid stop block may cause considerable change of spring characteristics of the vibration-damping device, making it impossible for the device to exhibit moderate load-spring characteristics.
[Citation 1]                JP-A-3-9138
[Citation 2]                JP-B-3-30736
[Citation 3]                JP-A-4-160244
[Citation 4]                JP-U-1-149044

Fluid filled cylindrical vibration damping device


Systems and methods for performing large-radix numeric operations. A first number may be segmented into large-radix segments, wherein numbers of the segments are generated such that radix of the segment is greater than radix of the first number. As a result, a plurality of disparate processor-based computing systems may be configured to perform various numeric operations on the large-radix segments of the number and output results of a numeric operation as a number whose radix is equal to the radix of the first number.

Since most modern digital computers are transistor based, binary numbers have been traditionally used for internal computer processing. The binary number system, also known as radix-2, consists of just two unique numbers, 0 and 1, which conveniently represent the "off" and "on" states of a transistor element. In contrast, humans generally use decimal number system, also know as radix-10, which consists of numbers 0 through 9 coinciding with 10 fingers of two hands. To interact with a computer, decimal-based input data is converted to binary for computer processing. Thus, for example, when a calculation involves integers, a decimal number is represented as powers of 2 (i.e., 2n, . . . 24, 23, 22, 21, 20), whereby decimal 23 corresponds to binary 10111. When these calculations involve fractional numbers, the results are represented as sums of inverse powers of 2 (i.e., ½, ¼, ⅛, 1/16 . . . ½n), whereby one tenth ( 1/10) corresponds to a repeating binary fraction 0.00011 0011.
Due to design limitations, most modern computers cannot effectively represent repeating binary fractions. In particular, a typical computer system recognizes several native data types, including integer, single-precision floating point, double-precision floating point and character. One of the differences between these data types is the amount of memory allocated by the system to each data type. On a typical 32-bit system, characters are often stored in 8 bits, a short data type is 16 bits, integer and single-precision floating point numbers are 32 bits, and double-precision floating point numbers are 64 bits. As a result, due to the limited memory provided by a typical computer system for representation of data, a repeating binary fraction may be truncated and rounded off to fit into the available memory. This can lead to rounding errors that cause results calculated in radix-10 and those calculated in radix-2 to be different. The differences can easily escalate when many of such rounded-off numbers are multiplied or added resulting in significant discrepancies between the decimal and binary representations. This can be problematic in many applications, especially those dealing with monetary and monetary exchange calculations.
Some of these problems can be avoided if calculations are done by the computer in a radix-10 based number system. The two most popular approaches to the radix-10 computer arithmetic are large binary integers and small decimal digits techniques. The large binary integer solution requires writing software functions that allow calculation of large integers (e.g., 256 bit integers). Calculations can be done rapidly, but it can be very difficult to determine decimal point placement for addition and subtraction, because the number is in binary, but the decimal point needs to be placed between decimal digits. Therefore this approach is generally used for fixed point calculations (e.g., calculations where the decimal point is in a fixed location in the numbers to be processed). This approach ignores the decimal point in the calculation and simply implies it in the result. The only place where the decimal point is acknowledged is when a number needs to be displayed. This also requires that all calculations be done at the same precision in order to avoid the problem of aligning two binary numbers for a decimal operation, like addition.
Another approach is the small decimal digit approach which generally uses one-half to one byte (8 bits) to store a decimal digit. Thus, each decimal digit (0-9) is encoded by a corresponding four-bit binary number, so that a sequence of decimal digits can then be represented by concatenating the four-bit binary numbers. This makes placing the decimal point easier, but the calculation is much slower because each decimal digit is handled separately. In addition, there is a significant loss of storage efficiency because four bits can store decimal numbers 0-15 but are used in this approach to store only numbers 0-9. Furthermore, similar to the large binary integer approach, implementation details for the small decimal digit method differ significantly from processor-to-processor. This makes creating a platform-independent solution difficult.

System and methods for large-radix computer processing


A flat harness winding device includes: a case; a rotor rotatably disposed in the case; a shaft of the case inserted into a hole in the center of the rotor; a plurality of harness split rollers rotatably disposed in the rotor; and a plurality of flat harnesses each of which one end is fixed to the shaft, said flat harnesses independently bent along respective harness split rollers and guided out from an opening of the case allowed to be wound. Harness support rollers are rotatably disposed on the rotor in spaces between the harness split rollers. Curve-shaped harness guide ribs are disposed on the rotor close to an out side in a radial direction of each harness split roller.

FIG. 4 shows an embodiment of a conventional flat harness winding device.
This flat harness winding device 51 has a disc-shaped rotor 53 in a circular ring-shaped case 52. The rotor 53 is provided with a reverse roll 54 having a large diameter and a plurality of guide rolls 55 each having a small diameter both rotatably and pivotally supported. A flat harness (flat cable) 58 fixed to a circular wall 56 in the center of the case 52 with a clamp 57 is folded back along the reverse roll 54 via a circumference of the circular wall 56, curved along the guide rolls 55, and guided out freely from a guiding path 59 of the case 52. The rotor 53 is biased in a harness winding direction with a center coil spring 60.
One end of the coil spring 60 is fixed to a hollow shaft 61 in the center of the rotor 53, and the other end of the coil spring 60 is fixed to a slit 62 in the center of the case 52. The case 52 is composed of a lower case and an upper case. A fixed side 58a of the flat harness 58 is guided out from the other guiding path via the clamp 57. The fixed side 58a of the flat harness 58 is routed to a fixed body (not shown), and a movable side 58b of the flat harness 58 is routed to a movable body (not shown). Two flat harnesses 58 are laminated in a thickness direction. The number of the flat harnesses 58 is optional.
From a winding condition of the flat harness 58 shown in FIG. 4, when the movable side 58b of the flat harness 58 is extracted against the bias of the coil spring 60, the rotor 53 is rotated in the clockwise direction together with the rolls 55 and the reverse roll 54 rotates in the clockwise direction. Thereby, a flat harness portion around an outer periphery of the circular wall 56 is released, and the reverse roll 54 is moved close to the clamp 57 in the clockwise direction.


A universal modular glottiscope system includes a set of differently dimensioned elongate tubular elements for insertion into a patient's larynx for laryngoscopic procedures or intubation. Each tubular element has a substantially triangular cross-section distally defined by a substantially planar base and two curved sides which intersect at an apex line and may have varying curvature between the apex line and the base. A distal end opening is defined by an intersection of the cross-section with an imaginary plane at a selected angle to the longitudinal direction of the tubular element. At the proximal end of each tubular element, which is D-shaped in configuration and wider than the distal end, is provided a pair of opposed end slots intermediate the apex line and the base. The planar base is detachable. Above the slots, adjacent the proximal end of each tubular element, is a standardized handle-attachment fitting. A surgeon using the system may inspect the patient and, based on measurements and/or experience, select the most suitable elongate tubular element from the set and manually attach a standardized handle element thereto at the standardized handle-attachment thereof.

Instruments generally known as laryngoscopes are routinely used to facilitate endotracheal intubation of patients, e.g., to provide a temporary air passage for administration of anesthetic substance or to overcome an obstruction of the air passage to a patient's lungs. Laryngoscopes, in various forms, are also commonly used in surgery to displace oral cavity and pharyngeal tissues to enable a surgeon to perform direct inspection and surgical manipulation of a patient's larynx, a procedure known as direct laryngoscopy. The typical laryngoscope has an elongate portion, which may be of adjustable geometry, that is introduced through the patient's mouth into the larynx. An attached handle enables the surgeon to manipulate not only the portion introduced into the patient's larynx but, as appropriate, to position the distal end of the inserted element to perform inspection and/or surgical operations. One or more surgical tools may be inserted simultaneously via the inserted element. Otolaryngologists typically use a laryngoscope having a tubular portion insertable into the patient's larynx to the glottis, i.e., the true vocal cords or folds, both for viewing and for endoscopic surgical operations thereon.
The surgeon must have a clear view of the affected tissue and must be able to perform precise surgery, sometimes with more than one tool utilized simultaneously. Because of the limited dimensions of the human oral cavity, pharynx and larynx, and the inevitable discomfort suffered by the patient in such a procedure, it is extremely important to enable the surgeon to have the widest access and maximum freedom for manipulating necessary instrumentation, and to reduce the time during which physical invasion of the patient's larynx must occur.
Particularly for patients who need to improve or maintain their voices, specialized surgery known as phonomicrosurgery is performed with the use of a surgical microscope. Such phonomicrosurgery is optimized by obtaining the widest glottal surgical field to expose vocal-fold anomalies such as polyps, nodules, cysts, granulomas, papilloma, epithelial dysplasia, and cancerous growths.
The human vocal folds (glottis) comprise an approximately isosceles-triangle-shaped valve that is fixed anteriorly and opens and closes posteriorly to allow for respiration and phonation, respectively. Lesions of the vocal folds may occur in patients of all ages and of both genders. A clear human voice is predicated on aerodynamically-driven, symmetrically-entrained oscillation of the vocal folds. When the vocal folds are closed during phonation, the expired air stream from the trachea is opposed by the closed glottal valve. Under sustained aerodynamic pressure, the vocal folds will vibrate to generate phonation. This vibration becomes disordered, and hoarseness develops, if there is a lesion on the vocal folds. Most benign lesions of the vocal folds, except lesions caused by viral infection, tend to develop in vocal over-users.
Successful phonomicrosurgery depends on maximal preservation of the layered microstructure of the healthy vocal fold tissue and is facilitated by the largest appropriately-shaped laryngoscope that can be placed between the patient's lips and glottis. Accordingly, the optimal laryngoscope will be one which facilitates ideal exposure of the pathology and, in turn, hand-instrument examination and retraction of the lesion for examination and resection.
In the known prior art, the problem of effectively angulating hand-held and operated instruments within the lumen of the laryngoscope element inserted into the patient's mouth and larynx was solved in two ways: by forming the lumen structure to have a widened proximal aperture of a tubular laryngoscope or, in the alternative, by using a bivalved spatula laryngoscope comprised of two pivotably separable distending spatula blades. The latter tends to be unstable distally away from the distending mechanism. A single slot was sometimes provided in the lumen to facilitate manipulation of proximal end portions of surgical instruments therein, but this provided room for instrument manipulation on only one side of the laryngoscope. The prior art furthermore suffers from an inability to provide the dimensional versatility required when treating patients of differing anatomy.
A need exists for a modular glottiscope system which enables a surgeon to treat patients of different sizes, permits access to specific portions of the larynx with greater precision and comfort for the patient, and permits flexibility in manipulation of one or more viewing and/or surgical tools and, because of its modular variations, easily adapts for intubation applications. The present invention is intended to meet all of these needs.

Universal modular laryngoscope/glottiscope system