A process for producing continuously an aromatic polycarbonate oligomer by reacting an aromatic dihydroxy compound and an alkali metal base or an alkaline earth metal base with a carbonyl halide compound comprises:. (1) feeding continuously to a tank reactor an aromatic dihydroxy compound, water, a molecular weight controlling agent, a polymerization catalyst, a carbonyl halide compound, and an organic solvent, and an alkali metal base or an alkaline earth metal base in an amount of 1.15-1.6 equivalents based on the aromatic dihydroxy compound, PA0 (2) carrying out the reaction with a residence time as defined by the following formula, EQU log Y<-2.19X+1.84 (0.0005.ltoreq.X<0.84,1.ltoreq.Y<69) PA0 where X is an amount of the polymerization catalyst in terms of mole % based on the amount of mole of the aromatic dihydroxy compound fed per unit time, and Y is a residence time (min.), and PA0 (3) continuously withdrawing the reaction mixture from the tank reactor to obtain an aromatic polycarbonate oligomer having a number average molecular weight of 1,000-10,000. An aromatic polycarbonate is produced by polycondensation of the aromatic polycarbonate oligomer.

1. Field of the Invention
The present invention relates to processes for producing an aromatic polycarbonate oligomer and an aromatic polycarbonate.
2. Description of the Related Art
Heretofore, there have been known methods for producing continuously an aromatic polycarbonate oligomer or an aromatic polycarbonate by reacting an aqueous alkali metal base or alkaline earth metal base solution of an aromatic dihydroxy compound with a carbonyl halide compound.
For example, as a continuous method for producing an aromatic polycarbonate oligomer, there are known methods disclosed in Japanese Patent Publication Nos. Sho 46-21460 (U.S. Pat. No. 3,646,102) and Sho 56-44091 (U.S. Pat. No. 4,089,888). These methods do not use any polymerization catalyst and molecular weight controlling agent.
These methods use a tubular reactor, and are useful when such type of reactor is available. However, it is often preferable to use a more conventional apparatus for various purposes such as a tank reactor with a stirrer and the like.
In addition, when a tubular reactor is used, an organic solvent is vaporized in the tube at a high reaction temperature and cavitation, clogging and the like occur, and therefore, stricter cooling is often required than in the case of a tank reactor.
Further, in the above-mentioned methods for producing an aromatic polycarbonate oligomer, the haloformation reaction (production of an aromatic polycarbonate oligomer) is carried out in the absence of a molecular weight controlling. Therefore, a molecular weight controlling agent is added to the aromatic polycarbonate oligomer thus produced and then a polycondensation reaction is effected to produce an aromatic polycarbonate. However, this method has the disadvantage in that the rate of end capping of the resulting aromatic polycarbonate is very low.
Aromatic polycarbonates are thermoplastic polymers, and with respect to recycling of plastics to which people have recently paid attention, aromatic polycarbonates are advantageous since the recycling can be easily effected.
However, it is known that in the case of an aromatic polycarbonate having a low rate of end capping, rearrangement of the high polymer chain occurs when melted and the molecular weight and the molecular weight distribution change [Kobunshi Kagaku, 21, 505 (1964); J. Polymer Sci., 55, 251 (1961)].
It is well known to those skilled in the art that molecular weight and molecular weight distribution most closely relate to physical proporties of polymers, and when such phenomena as described above occur, physical properties of the aromatic polycarbonates disadvantageously change or deteriorate when performing melt-shaping during recycling of the aromatic polycarbonates.
Therefore, a method for producing aromatic polycarbonates having a very high rate of end capping and a high polymer chain which is hardly rearranged is strongly desired.
It is known that aromatic polycarbonates can be continuously produced by a haloformation reaction in the presence of a molecular weight controlling agent.
For example, according to the process of British Patent No. 923,192, an aromatic dihydroxy compound, a molecular weight controlling agent, an aqueous solution of sodium hydroxide and phosgene are fed to the first reaction vessel in a series of four or five consecutively linked vessels and reacted. A polymerization catalyst is added to the second or the third reaction vessels where the reaction further proceeds, so as to carry out the polycondensation. As a result, an aromatic polycarbonate is produced.
However, when an aromatic polycarbonate is produced by the haloformation reaction in the presence of a molecular weight controlling agent, the rate of end capping of the resulting aromatic polycarbonate is as low as about 70-80%. In addition, according to the process of British Patent No. 923,192, the amount of hydrolysis of the carbonyl halide compound is not a negligible amount upon producing an aromatic polycarbonate.
On the other hand, it is also known to produce an aromatic polycarbonate in the presence of a polymerization catalyst.
For example, a liquid aqueous phase, a liquid organic phase and a gas phase containing phosgene are fed to a reactor containing packing in the presence of an amine or its salt. The reaction mixture passing through the final reactor is separated into a liquid phase and a gas phase, followed by isolating the reaction product from the liquid phase to obtain a high molecular weight linear polycarbonate [Japanese Patent Application Laid-open No. Sho 47-14297 (U.S. Pat. No. 3,787,359)].
As another example, a polycarbonate is prepared by a phase boundary condensation method comprising phosgenation of an aqueous alkali metal salt solution of one or more aromatic dihydroxy compounds in which process an aromatic chlorinated hydrocarbon is used as the solvent. The synthesis of the polycarbonate is carried out in two stages. In the first stage, the reaction of the alkali metal salt solution of the aromatic dihydroxy compound(s) with phosgene is carried out at an OH concentration of between 0.01 and 0.1% by weight of OH, relative to the aqueous phase, in the presence of 0.1 to 2.5 mole % of trialkylamine, relative to aromatic dihydroxy compound(s), and at a temperature higher than 70.degree. C. with a dwell time of less than 5 minutes. In the second stage, the polycondensation is effected by adjusting the OH concentration to 0.20 to 0.50% by weight of OH, relative to the aqueous phase, optionally with further addition of trialkylamine, at a temperature higher than 80.degree. C. and with a dwell time of more than 1 minute [Japanese Patent Application Laid-open No. Sho 50-122,595 (U.S. Pat. No. 4,038,252)].
According to the method of Japanese Patent Application Laid-open No. Sho 47-14297 (U.S. Pat. No. 3,787,359), there is used a reactor such as a packed column containing packing. Therefore, the stirring and mixing can not be efficiently effected as compared with the production of an aromatic polycarbonate using a tank reactor and the amount of hydrolyzed carbonyl halide compound increases disadvantageously.
According to the method of Japanese Patent Application Laid-open No. Sho 50-122,595 (U.S. Pat No. 4,038,252), the polymerization catalyst and the molecular weight controlling agent are added upon the haloformation reaction. Therefore, the rate of end capping is fairly improved and hydrolysis of the carbonyl halide compound is considerably suppressed.
The present inventors studied the above-mentioned method and found that when the aromatic dihydroxy compound was reacted with the carbonyl halide compound under conditions of low OH concentration in the aqueous phase in the presence of a trialkylamine, a decomposition reaction of the trialkylamine occurred, and the nitrogen content in the resulting aromatic polycarbonate increased. In general, such increased nitrogen content causes coloration of the aromatic polycarbonate upon high temperature shaping so that the aromatic polycarbonate thus shaped does not have a desirable color.
Therefore, there is desired a method for producing an aromatic polycarbonate having a low nitrogen content and a high rate of end capping while suppressing hydrolysis of a carbonyl halide compound.
The above-mentioned British Patent No. 923,192 discloses that polymerization catalyst is desirably added to the first tank reactor or the following tank reactor(s), preferably, to a later tank reactor where the reaction has fairly proceeded, but nothing is mentioned about the amount of the polymerization catalyst and the residence time in the tank reactor.
In the working example for producing an aromatic polycarbonate using a continuous tank reactor apparatus, the residence time in the first tank reactor is 4-5 min and a polymerization catalyst in an amount of 0.89 mole % based on the aromatic dihydroxy compound is added in the second or third tank reactor.
However, when the present inventors studied the example by adding the same amount of the polymerization catalyst to the first tank reactor, it was difficult to control the molecular weight and therefore, the resulting aromatic polycarbonate had a wide distribution of molecular weight.

Processes for producing aromatic polycarbonate oligomer and aromatic polycarbonate


A surfing rope (20) for towing a surfer behind a boat or upon moving water is disclosed. The surfing rope is constructed from a length of braided rope (22) having a plurality of nodules (24) intermittently spaced along the rope's length for gripping by the surfer. The nodules are formed by a plurality of inserts (26) strung on to an inner cord (34) that is threaded through the braided rope.

Proficiency in surfing can only be obtained by practice. However, in regions of the country where the waves necessary for surfing are unavailable, wave conditions are poor, or access is inconvenient, it is necessary to turn to any alternative source for waves. One alternative source of waves derives from the use of watercraft, typically motorboats. Waves are formed by the stem wake of a boat as the boat moves through the water. Different magnitudes of waves can be generated depending upon the speed of the boat and the hull design.
In certain instances, the waves produced are of sufficient magnitude to support surfing practice. The waves simulate natural wave motion, but are generally insufficient to propel a surfer along. Thus, the wake surfer grips a tow rope secured to the stern of the boat, and rides a surfboard on the waves generated by the boat while being towed behind the boat. The wake surfer is able to grip the rope with one or both hands while still maintaining the traditional surfing body position.
In order to wake surf different sections of the wave and thus practice different surfing technique, the wake surfer should preferably be able to vary his or her distance from the stem of the boat while maintaining a secure grip on the tow rope. Additionally, the wake surfer needs to be able to easily vary his or her posture (which generally is facing perpendicular (sideways) to the path of travel) as the surfer moves up and down various positions on the stem wake.
Typically wake surfing has been practiced with the aid of conventional water-skiing tow ropes. Such conventional tow ropes typically consist of a long length of rope, often a polypropylene braided rope, having a handle, such as a stirrup or bar, integrated into one end. The other end of the rope is securable to the boat. Although the tow rope length may be varied by securing the rope to the boat at differing points along the rope's length, once the tow rope is secured, the length of the rope is fixed. If a wake surfer were to grasp the rope at a point other than the handle, so as to change the distance between the surfer and the boat, the rigid handle is left to knock about the surfer. The transverse bar or stirrup handle of conventional water-skiing tow ropes also does not facilitate grasping the rope when standing up in a traditional surfing posture.
Further, no gripping device other than the handle is provided at other points on conventional water-skiing tow ropes. Thus a wake surfer is unable to obtain a firm grasp at points along the length of the rope to prevent the rope from sliding through the surfer's hands. Some conventional water-skiing tow ropes have a thickened section adjacent the handle that would provide for a somewhat firmer grip, but still do not provide a way to assuredly prevent slippage of the rope. Thus, conventional water-skiing tow ropes are inappropriate for a wake surfer who wishes to vary his or her distance from the end of the motorboat, and posture, while surfing.
In a further type of surfing, individuals stand on wooden platforms or surfboards in the swift currents and rapids of fast moving streams and rivers. A "river surfer" holds on to a rope tied to a rock, tree or other stationary object. The river surfer maneuvers himself/herself about the currents and rapids by "working" the board in a manner similar to the surfer being towed behind a boat, i.e., the river surfer shifts his/her weight and moves his/her position relative to the board and also moves back and forth along the length of the restraining rope.
To date the restraining rope used by river surfers is typically composed of a basic climbing rope. Thus the rope must be secured to the board or very tightly grasped to prevent the rope from sliding through the river surfer's hands.


An image forming apparatus capable of readily changing the pixel density of an image to be formed on an image carrier and, therefore, stabilizing image reproduction. To change the pixel density, the apparatus turns on, among light emitting elements arranged in a higher density than input image data, a plurality of light emitting elements per pixel or by changing the number of light emitting elements per pixel and the turn-on time thereof.

The present invention relates to a digital image forming apparatus for forming an image on an image carrier in response to input image data.
One of conventional digital copiers, printers or similar image forming apparatuses generates image data to be written in response to image data sent from an input device, exposes the precharged surface of a photoconductive element, or image carrier, on the basis of the image data to electrostatically form a latent image, and develops the latent image by a toner. This type of apparatus often uses a light emitting diode (LED) array as means for exposing the photoconductive element. An LED array implements high-speed printing and broad-width printing, compared to laser optics which scans a photoconductive element by a single laser beam. Further, since the LED array extends in the main scanning direction, it insures high positional accuracy in the main scanning direction on the photoconductive element.
In parallel with the spread of digital image forming apparatuses, there is an increasing demand for high image quality in the total sense. There is also a keen demand for outputting methods each matching a particular kind of image due to the diversifying input system and diversifying document image. One conventional approach for meeting such demands is to change the pixel density of an image to be written in the photoconductive element by the exposing means. Laser optics, for example, changes the pixel density of an image by reducing the spot size of the laser beam and subjecting the laser beam to various kinds of modulation. However, since laser optics forms an image by manipulating a single beam, it cannot change the pixel density unless the construction thereof is drastically changed. Moreover, it is difficult with such laser optics to control the writing position on the photoconductive element. Laser optics with a special configuration would increase the size and cost of the entire apparatus.

Image forming apparatus capable of readily changing the pixel density of an image


A single aperture confocal scanning biomicroscope is disclosed with an illumination system having a pair of lenses surrounding an aperture for collimating a field of light, a pivotally mounted flap for blocking a central portion of the light in order to create peripheral illumination, and an aperture assembly comprised of a cylindrical lens, aperture, and beam splitter which is oscillated within the light field in order to create an aperture size optical beam for scanning a patient's eye and ocular adnexae. With the illumination system of the present invention, techniques involving both direct illumination and indirect illumination may be utilized in examining the eye to produce a true confocal image thereof. Single aperture confocal scanning techniques may be brought to existing slit lamp biomicroscopes with a kit comprised simply of a pair of lenses and an aperture in one embodiment which utilizes the existing illumination system. In a second embodiment, a completely new illumination system is also utilized which provides for examination techniques utilizing both direct and indirect illumination.

The slit lamp biomicroscope, or slit lamp as it is commonly referred to, is a versatile instrument used for examining the eye and ocular adnexae. It consists of a biomicroscope, an illumination source, and a mechanical supporting system which facilitates the positioning of the illumination source at various angles to the eye in order to achieve different kinds of examinations. The biomicroscope is an optical device which presents an enlarged image of the patient's eye to the observer and may be either a simple or compound biomicroscope with the latter having the advantages of additional magnification and less aberration than in a single lens system. Most typical prior art compound biomicroscopes present a real and inverted image, which can be corrected using a prism correction system. All slit lamp biomicroscopes achieve stereopsis by having a conversion angle between the separated oculars. However, there are many optical systems used to change magnification. These include rotating objectives, those that operate based on a Galilean telescope principle and those that function with zoom optics.
In examining the structures of the anterior segment of the eye, there are four different techniques that are presently employed with the prior art slit lamp biomicroscope. The first and most common of these is that of direct illumination. This technique involves focusing a beam of light through relatively transparent media and observing the scatter of light against a dark background. There are several forms of scatter illumination which are helpful in selected aspects of the ophthalmic examination. Thus, it is useful for this type of examination to observe scatter illumination in various parts of the eye.
A second technique of slit lamp examination is retro-illumination. With this method, light is reflected off of a diffusing surface to illuminate a more anterior structure in the eye. Thus, light may be bounced off the iris to illuminate the cornea or be reflected off of the fundus to examine the iris or lens. The image from this technique, as well as the technique of direct illumination, is degraded by reflections and by scatter from objects anterior from or posterior to the plane of interest.
A third technique in eye examination is sclerotic scatter. In this method, the incident slit light beam is oriented in an oblique fashion to the eye so that light falls on the limbal area of the cornea. As the angle of incidence is greater than the critical angle, light is reflected internally along the cornea similar to light traveling in fiber optic tubing. Additionally, some retro-illumination also occurs due to light scattered onto the iris or other posterior structures. While this technique is intended to visualize scars or opacities within the corneal stroma, the intense amount of scatter experienced reduces the resolution of the image and, hence, the value of this technique.
A fourth technique for anterior segment examination is that of specular reflection. This method utilizes the difference in index of refraction between the cornea and aqueous humor or the corneatear film and air, allowing visualization of either the corneal endothelium, or epithelium respectively. Occasionally, the anterior and posterior surface of the lens and the zones of discontinuity within the lens can be appreciated. Specular reflection is observed only monocularly, because the illumination beam blocks one of the observation paths. The image created with this technique of examination is degraded due to reflections from other portions of the corneal endothelium or epithelium or other ocular structures. In all four of these techniques of examination, the ocular images are also limited by the available contrast between the subject of interest and surrounding tissue. In addition, the closer the index of refraction is between the two interfaces the less the specular reflection will be, thereby reducing the amount of returning light forming the image to be observed.
While there are accessory devices available in the prior art designed to improve the aforementioned techniques of eye examination with the slit lamp biomicroscope, light reflection and scatter degrade those techniques utilizing direct illumination while limited tissue contrast and low levels of returning light limit the resolution of those techniques utilizing indirect illumination. Also, there is at least one tandem scanning confocal biomicroscope in the prior art which utilizes separate apertures and light paths to achieve some improvement over the typical slit lamp. However, difficulties of complexity and alignment are expected to limit its usefulness, as with tandem scanning confocal microscopes.
To solve these and other problems with the prior art slit lamp biomicroscope, the inventors herein have succeeded in designing and developing a single aperture confocal scanning biomicroscope, as well as two variations of a kit for converting existing slit lamp biomicroscopes into single aperture confocal scanning biomicroscopes. The many advantages of single aperture confocal scanning microscopy over dual aperture confocal microscopy are explained in the parent patents. Confocal microscopy includes the technique of illuminating only a small portion of the specimen at a time, and masking the returning (reflected or fluorescence) light to view only that same small portion to minimize the effects of scattered and out of focus light from surrounding portions of the specimen. The entire specimen is viewed by scanning it in small increments and coalescing these increments either in real time or with a video camera and image processor or the like. Other advantages of single aperture confocal scanning microscopy are to be found in the parent patents referred to, supra. With this invention, the many advantages of single aperture confocal scanning microscopy are brought to the instrument used to examine the eye and thereby minimize the major problems with the prior art slit lamp.
In one of the preferred embodiments, a significant part of the invention includes an improved illumination system. In the improved illumination system, a set of three cylindrical lenses is used to converge the light along the width of the masking aperture and an additional cylindrical lens positioned orthogonally to the first set is used to independently converge the light along the length of the masking aperture. Incorporated in the illumination system is a single assembly comprised of a cylindrical lens, masking aperture, and beam splitter which is oscillated as an integral unit which provides major advantages over other single aperture confocal scanning optical devices. Essentially, the illumination system includes a light filament and a curved reflector for concentrating a large portion of the light emanating from the filament into a pair of lenses with an aperture positioned therebetween in order to collimate the light into an incident light field. The collimating aperture is preferably a rectangular slit with cylindrical lenses, although a pin hole aperture and spherical lenses can be used. With a rectangular slit, the generally rectangular filament should be aligned with its long axis parallel to the slit's long axis. This lens pair and aperture thus aid in producing an incident light field of highly collimated light along the width of the masking aperture utilizing a large portion of the incident light produced by the filament. A cylindrical lens between the lens pair and aperture assembly focuses the incident light field along the length of the masking aperture into a field plane thereat.
The assembly mentioned above (aperture assembly), including a lens, a masking aperture, and a beam splitter, is positioned within the light field beyond the last mentioned cylindrical lens and further focuses the incident light field along the width of the masking aperture into an aperture size beam at the masking aperture. Additionally, a pivotally mounted variable V-shaped flap may be used to block a variable central portion of the light field so as to create an aperture size incident light beam comprised essentially of the edge portions of the light field. By doing so, only that light entering the lens at a relatively oblique angle is utilized which can optimally minimize the volume of intersection between the incident light and the return light path. Not only does this achieve dark field illumination of the specimen but it also minimizes scattering within all planes in the return light path with the exception of the specimen plane. This latter feature which is achieved with this "peripheral illumination" helps to maximize optical sectioning.
The particular lens used in the aperture assembly is a cylindrical lens which focuses the light along its width through the masking slit aperture. By matching the lens with the masking aperture, the aperture size beam may actually be focused within the contour of the masking aperture such that there is no backscatter from the aperture and virtually all of the incident beam passes therethrough. This further concentrates the incident light beam and provides a marked improvement to contrast as backscatter from the aperture is eliminated as a component of the light returning to the viewer. The pivotally mounted flap or peripheral illuminator may be included as part of the assembly which is oscillated within the conjugate field plane, if desired. All of the foregoing including the incident light source, lens pair and collimating aperture, cylindrical lens focusing along the length of the masking aperture, pivotally mounted flap, and aperture assembly of lens, masking aperture, and beam splitter, all comprise the illumination system which may be used to replace the slit lamp illumination system in the prior art.
Another pair of lenses then focuses the incident light beam at the specimen plane. Light reflected from the specimen is similarly focused by the same lens pair at the masking aperture and is masked thereby. Thus, light returning from the specimen is masked by the masking aperture in the preferred embodiment, but not the light illuminating the specimen. The returning light passes through the beam splitter to a biomicroscope objective as is well known in the art and the observer is thus presented with a confocal image of the eye which is illuminated either with direct illumination or with peripheral illumination. As is well known in the art, a pair of erector prisms may be used anywhere in the return light to re-orient the image in the upright direction, and hence are not shown.
The single aperture confocal scanning biomicroscope of this invention may be provided as a complete device, or the illumination system and lens pair may be provided as a retrofit kit to adapt existing slit lamp biomicroscopes for use as a single aperture confocal scanning biomicroscope.
In still another alternative, the lens used as part of the aperture assembly may be a double compound cylindrical lens; or may be a pair of cylindrical lenses bonded together, or may be a spherical lens in the event the cylindrical lens focusing along the length of the masking aperture is eliminated; or the lens may focus the light only along its width for some applications.
A somewhat simpler embodiment is also disclosed herein comprised of an aperture, an aperture oscillator, and a pair of lenses, with an alternative of a third lens or prism assembly for reinverting the image. In this embodiment, the original illumination system of a prior art slit lamp biomicroscope is utilized except that the masking aperture is placed at the original specimen plane, and the pair of lenses are used to refocus the incident light at a new specimen plane. Means are provided for moving the masking aperture within the conjugate field plane in which it is placed. In this embodiment, the masking aperture may have a multitude of openings through which the incident light may pass to illuminate the specimen. For example, a rotating Nipkow disc or an oscillating multi-slit aperture could be used. The third lens or erector prisms may be disposed in the returning light path to reinvert the image for viewing by the observer. As this embodiment utilizes the existing illumination system of the slit lamp and thus does not provide peripheral illumination, its performance is not nearly as dramatically improved as with the first embodiment described above. Additionally, in this embodiment, the mirror of the illumination system blocks a portion of the return light from the image causing resolution to suffer. Replacing the mirror with a beam splitter would prevent this blockage, but this is generally inconvenient in most biomicroscopes of prior art design.
While the principal advantages and features of the present invention have been explained above, a greater understanding of the invention may be attained by referring to the drawings and description of the preferred embodiment which follow.

Single aperture confocal scanning biomicroscope and kit for converting single lamp biomicroscope thereto


A hot-wire type air flow meter for an internal combustion engine has an exothermic resistor film provided on a thin portion formed on a silicon substrate and a control circuit for controlling a voltage to be applied to the resistor film or a current to be supplied. The resistor film is arranged in a suction pipe of the internal combustion engine and heat is emitted to an air through the resistor film. In the case where a liquid droplet is deposited onto the resistor film, the control circuit controls the applied voltage to a value smaller than a voltage which is applied to the resistor film at the time of measuring a maximum specified measuring range or controls the supply current to a value smaller than a current flowing in the resistor film at the time of measuring the maximum specified measuring range.

1. Field of the Invention
The invention relates to a measuring apparatus of an air flow rate and, more particularly, to a hot-wire type air flow meter (heat flow meter) suitable for detection of a suction air flow rate of an internal combustion engine.
2. Description of Related Art
Hitherto, as an air flow rate measuring apparatus which is provided for an electronic control type fuel injection apparatus of an internal combustion engine such as an automobile or the like and measures a suction air flow rate, a number of hot-wire type apparatuses have been used because a mass air flow rate can be directly detected. In this instance, to assure a reliability of an exothermic resistor, a sensor having a certain extent of heat capacity which is constructed by winding a platinum wire around a bobbin and coating it with glass, forming a thin film resistor onto a ceramic substrate, or the like is often used. In a sensor having a large heat capacity, although a system such that a current is limited when a waterdrop is deposited onto a portion other than an internal combustion engine has been shown in JP-A-5-264312, a power voltage is large to be 24V and a measuring region of a rated value or more is limited. Such a system is used, particularly, for measurement of a flow rate of the compressed air and there is a problem that although a waterdrop is instantaneously evaporated usually at 100xc2x0 C. at an atmospheric pressure, in the compressed air, an evaporation temperature of the water is high, it takes time to evaporate the waterdrop, and an excessive current flows in an exothermic portion. In this instance, since the power voltage is high to be 24V, when a waterdrop is deposited, a current which is one or more digits larger than a rated current flows, and accordingly, it is limited by a current limiter. In an internal combustion engine, to prevent a fusion of a hot wire, a system for reducing an applied voltage to a bridge by detecting a voltage across a hot wire resistor has been disclosed in JP-A-61-102522 or the like. According to such a system, to prevent the fusion due to the supply of the abnormal voltage because of noises or the like, a voltage limit value larger than the maximum value at the time of the stationary operation is set.
As a flow meter having a high response speed, a number of flow meters in which an exothermic resistor of a small heat capacity is attached on a silicon substrate have been proposed. For example, as shown in JP-B-5-7659, a thin film is formed on a silicon semiconductor substrate and a flow rate is detected by a thermal sensor.
In the conventional techniques mentioned above, in case of using an exothermic resistor of a large heat capacity, a response speed at the time of a power-on of an air flow rate measuring apparatus is determined only from the relation between a power source voltage and the heat capacity of the exothermic resistor. In an internal combustion engine such as an ordinary gasoline engine or the like, therefore, since a power source voltage is usually small to be about 12V, an operating current to the exothermic resistor is limited and it takes time to heat, so that it is difficult to accurately measure an air flow rate for a predetermined time at the start of an engine of an automobile or the like.
To improve the response speed, it is necessary to use an exothermic resistor of a small heat capacity. In a hot-wire air flow meter, however, the maximum flow rate which can be measured is limited unconditionally to a certain degree by the heat capacity and a heating temperature of the exothermic resistor which is used for measurement and by a power source voltage which can be applied. It is because when the heat capacity is small, if it is intended to raise a measuring sensitivity (maximum flow rate) of the flow rate by increasing the heating temperature, a limitation such that the exothermic resistor deteriorates when the heating temperature is equal to or higher than a predetermined value occurs. For example, a system such that an exothermic resistor is constructed by forming a thin film with a diaphragm structure onto a silicon substrate and a temperature of the exothermic resistor is controlled so as to become a constant temperature by a feedback circuit by using a bridge circuit or the like has the highest response speed. If a waterdrop, an oil droplet, or the like is deposited onto the exothermic resistor portion, however, a heating balance is broken and a voltage is applied so that the heating temperature of the exothermic resistor locally rises. Even in case of the applied voltage which does not cause a problem in the ordinary operation, therefore, if the temperature elevation continues, there is a possibility that the resistor of a small heat capacity constructed by the thin film is deteriorated by the heat and, in the worst case, the diaphragm is broken by a thermal stress.
Although the excessive temperature elevation can be prevented by limiting the voltage applied to the hot-wire type resistor so as not to locally raise the heating temperature of the exothermic resistor, there is a problem that a measuring range of the inherent flow rate is also narrowed.
It is, therefore, an object of the invention to provide a hot-wire type air flow meter for an internal combustion engine which can solve the problems of the conventional techniques mentioned above.
According to an aspect of the invention, there are provided: means for detecting a heating state of an exothermic resistor by distinguishing a case where a waterdrop, an oil droplet, or the like is deposited onto the exothermic resistor portion from a normal case where there is no deposition; and circuit means for limiting a heating time by the detected heating state. Thus, only in the case where the waterdrop, oil droplet, or the like is deposited onto the exothermic resistor portion, the heating state is limited without narrowing a measuring range of an inherent flow rate and a deterioration of the resistor can be prevented.

Hot-wire type air flow meter for internal combustion engine


A manually manipulatable tray is provided for supporting electrical connectors. The tray includes a thin sheet of formed plastic material having side walls, an open end, a closed end and a floor. The floor has a plurality of generally parallel, spaced-apart, upwardly extending rails generally parallel to the side walls and defining generally parallel channels therebetween. A pair of finger-gripping portions are formed on a respective pair of the rails spaced inwardly of the side walls a sufficient distance such that an individual can finger-grip the finger-gripping portions with the individual's hands substantially being within the side walls of the tray. The pair of finger-gripping portions are located on opposite sides of a mid-point located generally equidistant between the open and closed ends of the tray.

The automation of feeding and terminating electrical connectors has been ever-increasing in the connector industry to reduce labor costs and to increase speed and reliability of manufacture. However, with a corresponding ever-increasing trend toward miniaturization, difficulties continue to be encountered in handling large numbers of individual electrical connector components. Automatization, itself, has increased the problems of shipping, storing and automatic handling of such components. Specifically, many electrical connectors are manufactured/assembled in stages. Components may be produced, shipped and stored in intermediate assembly stages, and then the components are oriented and fed to automatic or partly automatic terminating machines.
One arrangement for handling such connector components is to use an elongated, generally tubular, hollow cassette having a uniform cross-sectional shape throughout its length and from which connector components are fed, such as feeding to automated terminating equipment. The cross-sectional shape of the cassette corresponds to the connector profile, and the cassette holds a serial array of the components. Feeding apparatus are provided at the automated terminating equipment or other assembly machine for unloading the cassettes and advancing full cassettes for replacing empty cassettes.
Another arrangement for handling such connector components is described in U.S. Pat. No. 4,770,591 to Wright et al, dated Sep. 13, 1988 and assigned to the assignee of this invention. In that patent, a packaging tray includes a matrix array of open-ended component receiving channels formed therein, each channel containing a serial array of electrical connectors. A box-like container holds a stacked array of the open-ended trays containing the connectors. The box has an open end in a common plane with the open ends of the channels of the trays. The connectors are fed, one at a time, from individual channels in a tray, and a shuttle is indexed along a row of channels, one channel at a time, until the tray is emptied. Thereafter, an adjacent tray containing another row of channels is brought into alignment for unloading.
A problem with the arrangement described in the U.S. Pat. No. 4,770,591 patent, above, is the difficulty of manually manipulating the trays filled with connector components. The trays are flat and difficult to balance, and the trays conventionally are formed from thin plastic sheet material and, consequently, are somewhat flimsy. In addition, loading the trays in a stacked array, one on top of another, in the box-like container is difficult because the edges of the trays cannot be grasped within the confines of the box-like container. As a result, connector components often are disturbed or moved out of their proper stored positions, entire trays can be spilled and the connector components, in fact, can be damaged. The present invention is directed to further improvements in packaging trays of the character described above, particularly in providing means for facilitating easy manual manipulation of the trays.

Packaging tray for electrical connectors


An effective desiccant for use in a package which has a material including at least in part solid particles of one or more materials, at least one of such materials having an average particle size range 0.001 to 0.1 micrometers to provide a high rate of water absorption and to provide an equilibrium minimum humidity level lower than a humidity level to which a highly moisture sensitive electronic device is sensitive within a sealed enclosure.

The present invention relates to control of moisture inside a packaged electronic device and relates particularly to an improved desiccant and desiccant package which desiccates highly moisture-sensitive electronic devices to prevent premature device failure or premature degradation of device performance.
Various microelectronic devices require humidity levels in a range of about 2500 to below 5000 parts per million (ppm) to prevent premature degradation of device performance within a specified operating and/or storage life of the device. Control of the environment to this range of humidity levels within a packaged device is typically achieved by encapsulating the device or by sealing the device and a desiccant package within a cover. Desiccant packages include a container for receiving solid water absorbing particles (a desiccant) or providing such particles into a binder. Examples of solid water absorbing particles include molecular sieve materials, silica gel materials, and materials commonly referred to as Drierite materials which are used to maintain the humidity level within the above range.
Particular microelectronic devices, for example, organic light-emitting devices (OLED) or panels, polymer light-emitting devices, charge-coupled device (CCD) sensors, and micro-electro-mechanical sensors (MEMS) require humidity control to levels below about 1000 ppm and some require humidity control below even 100 ppm. Such low levels are not achievable with desiccants of silica gel materials and of Drierite materials. Molecular sieve materials can achieve humidity levels below 1000 ppm within an enclosure if dried at a relatively high temperature. However, molecular sieve materials have a relatively low moisture capacity at humidity levels at or below 1000 ppm, and the minimum achievable humidity level of molecular sieve materials is a function of temperature within an enclosure: moisture absorbed, for example, at room temperature, can be released into the enclosure or package during temperature cycling to higher temperature, such, as, for example, to a temperature of 100xc2x0 C. Solid water absorbing particles used within such packaged devices include 0.2 to 200 xcexcm particle size powders of metal oxides, alkaline earth metal oxides, sulfates, metal halides, or perchlorates, i.e. materials having desirably relatively low values of equilibrium minimum humidity and high moisture capacity. However, such materials even when finely divided into powders of 0.2 to 200 xcexcm particle size often chemically absorb moisture relatively slowly compared to the above-mentioned molecular sieve, silica gel, or Drierite materials. Such relatively slow reaction with water vapor leads to a measurable degree of device degradation of performance following the sealing of the desiccant inside a device cover due to, for example, moisture absorbed on the inside of a device, moisture vapor present within the sealed device, and moisture permeating through the seal between the device and the cover from the outside ambient.
Some solid water absorbing particles, particularly molecular sieve materials which entrain moisture by physical absorption within microscopic pores, require a dehydrating step at substantially elevated temperature prior to use within a device enclosure, thus increasing the number of process steps and calling for additional apparatus, such as, for example, a controllable furnace to achieve substantial dehydration.
Selection of solid water absorbing particles and the method of applying selected particles to an inner portion of a device enclosure prior to sealing the device within or by the enclosure is governed by the type of device to be protected from moisture. For example, highly moisture-sensitive organic light-emitting devices or polymer light-emitting devices require the selection of particular solid water absorbing particles and methods of application, since organic materials or organic layers are integral constituents of such devices. The presence of organic materials or layers may, for example, preclude the use of certain solvents or fluids in the application of a solid water absorbing particles dispersed in a fluid to organic-based devices. Furthermore, a thermal treatment, if required, of a desiccant contained within a sealed device enclosure, needs to be tailored to the constraints imposed by thermal properties of the organic constituents or layers of the device. At any rate, release of solvent vapors during a thermal treatment of a desiccant disposed within a sealed device enclosure must be avoided or minimized if solvent vapors can adversely affect organic constituents of organic-based electronic devices. The aforementioned considerations pertaining to organic-based electronic devices may not be as important if the electronic device to be desiccated is strictly an inorganic or metallic device such as, for example, a MEMS device or a CCD sensor without an organic color filter overlay.
For highly moisture sensitive electronic devices, such as organic light-emitting devices or polymer light-emitting devices, VanSlyke, U.S. Pat. No. 5,047,687 teaches the use of a protective layer comprised of a mixture of at least one organic component of the organic electroluminiescent medium and at least one metal having a work function in the range of from 4.0 to 4.5 eV capable of being oxidized in the presence of ambient moisture. The metal in the protective layer is described by VanSlyke as being sufficiently reactive to be oxidized by ambient atmospheric moisture over an extended period of time when incorporated into the organic EL device. In this use the metal is used as solid water absorbing particles for moisture in the protective layer. That neither a coated layer of metal film alone nor successively coated layers of the metal and organic films were effective in preventing the dark spot growth due to ambient moisture was attributed to the slow oxidation of the bulk metal. VanSlyke, therefore, teaches that the oxidation susceptibility of reactive metals that can be oxidized by ambient moisture is enhanced by the higher surface to volume ratios achieved by co-deposition of the metal into a mixed layer of metal and an organic medium. However, VanSlyke does not teach the required metal desiccant particle size for optimal moisture absorption protection nor does he teach the effect of metal particle size on performance in protecting organic EL devices.
Numerous publications describe methods and/or materials for controlling humidity levels within enclosed or encapsulated electronic devices. For example, Kawami et al., European Patent Application EP 0 776 147 A1 disclose an organic EL element enclosed in an airtight container which contains a drying substance comprised of a solid compound for chemically absorbing moisture. The drying substance is spaced from the organic EL element, and the drying substance is consolidated in a predetermined shape by vacuum vapor deposition, sputtering, or spin-coating. Kawami et al. teach the use of the following solid water absorbing particles: alkali metal oxides, alkali earth metal oxides, sulfates, metal halides, and perchlorates. Kawami et al., however, do not teach the effect of particle size of these solid water absorbing particles on their performance.
Shores, U.S. Pat. No. 5,304,419 discloses a moisture and particle getter for enclosures which enclose an electronic device. A portion of an inner surface of the enclosure is coated with a pressure sensitive adhesive containing a solid desiccant with average particle size usually 0.2 to 100 xcexcm and preferably 0.5 to 10 xcexcm.
Shores, U.S. Pat. No. 5,401,536 describes a method of providing a moisture-free enclosure for an electronic device, the enclosure containing a coating or adhesive with desiccant properties. The coating or adhesive comprises a protonated alumina silicate powder with average particle size 0.2 to 100 xcexcm, preferably 1 to 10 xcexcm, dispersed in a polymer.
Shores, U.S. Pat. No. 5,591,379 discloses a moisture gettering composition for hermetic electronic devices. The composition is applied as a coating or adhesive to the interior surface of a device packaging, and the composition comprises a water vapor permeable binder which has dispersed therein a desiccant with average particle size of 0.2-100 xcexcm, preferably 0.3-50 xcexcm, which is preferably a molecular sieve material.
Many of the desiccants disclosed by Shores will not function effectively with highly moisture-sensitive devices at a humidity level lower than 1000 ppm. In addition, Shores does not teach why the particle sizes disclosed are chosen or the effect of particle size on the performance of the desiccants.
Similarly, binders, such as polyethylene disclosed by Shores, that have low moisture absorption rates compared to the absorption rate of the pure selected desiccants would not function effectively to achieve and to maintain a humidity level below 1000 ppm during a projected operational lifetime of a highly moisture-sensitive device.
Deffeyes, U.S. Pat. No. 4,036,360 describes a desiccating material that is useful as a package insert or on the interior walls of packaging boxes for applications requiring only moderate moisture protection, such as film or cameras. The material comprises a desiccant and a resin having a high moisture vapor transmission rate.
The desiccants disclosed by Deffeyes are alumina, bauxite, calcium sulfate, clay, silica gel, and zeolite, but Deffeyes does not describe the particle size of any of the desiccants. None of these desiccants will function effectively with highly moisture-sensitive devices at a humidity level lower than 1000 ppm. In addition the moisture vapor transmission rate requirement for the resin is not adequately defined since there is no reference to the thickness of the measured resins. A material that transmits 40 grams per 24 hrs per 100 in2 at a thickness of 1 mil would be very different than one that transmits 40 grams per 24 hrs per 100 in2 at a thickness of 100 mils. It is therefore not possible to determine if the moisture vapor transmission rates disclosed by Deffeyes are sufficient for highly moisture-sensitive devices.
Taylor, U.S. Pat. No. 4,013,566 describes solid desiccant bodies that are useful as drier materials in refrigerant fluid systems. The solid desiccant body comprises finely divided particles of desiccant material bound in a moisture transmissive aliphatic epoxy polymer matrix.
The desiccants disclosed by Taylor are molecular sieves, activated alumina, and silica gel. Taylor teaches the use of particle sizes 1 to 10 xcexcm, but does not teach the impact of particle size on desiccant performance. None of these desiccants will function effectively with highly moisture-sensitive devices at a humidity level lower than 1000 ppm. In addition the moisture vapor transmission rate requirement for the resin is not adequately defined; stating only that the solid desiccant bodies have rates of adsorption of absorption comparable to the desiccant materials alone. It is therefore not possible to determine if the resins disclosed by Taylor are sufficient for highly moisture-sensitive devices.
Booe, U.S. Pat. No. 4,081,397 describes a composition used for stabilizing the electrical and electronic properties of electrical and electronic devices. The composition comprises alkaline earth oxides in an elastomeric matrix.
The desiccants disclosed by Booe are barium oxide, strontium oxide, and calcium oxide. Booe teaches the use of particle sizes less than 80 mesh (177 xcexcm) to minimize the settling of oxides within the suspension. Booe does not teach the impact of particle size on desiccant performance. These desiccants will function effectively with highly moisture-sensitive devices at humidity levels lower than 1000 ppm; however, Booe claims the elastomeric matrix has the property of retarding the rate of fluid absorption of the alkaline earth particles. In the examples the water absorption rate of the compositions are 5 to 10 times slower than the alkaline earth particles alone. This decrease in absorption rate is disclosed as a desirable feature that improves the handling of the highly reactive alkaline earth oxides. In highly moisture-sensitive devices, however, any decrease in the absorption rate of moisture will increase the likelihood of device degradation, and identification of resins that will increase the absorption rate of moisture would be highly desirable. For highly moisture-sensitive devices, therefore, it is important to determine the minimum allowable water vapor transmission rate of the binders used in combination with effective desiccant materials.
Boroson et al., U.S. Pat. No. 6,226,890 describes a method of desiccating an environment surrounding a moisture-sensitive electronic device sealed within an enclosure, including selecting a desiccant comprised of solid particles having a particle size range 0.1 to 200 micrometers. The desiccant is selected to provide an equilibrium minimum humidity level lower than a humidity level to which the device is sensitive within the sealed enclosure. A binder is chosen that maintains or enhances the moisture absorption rate of the desiccant for blending the selected desiccant therein. The binder may be in liquid phase or dissolved in a liquid. A castable blend is formed including at least the desiccant particles and the binder, the blend having the solid water absorbing particles comprise 10 wt % to 90 wt % of the solid water absorbing particles and the binder.
The blend is cast in a measured amount onto a portion of an interior surface of an enclosure to form a desiccant layer thereover, the enclosure having a sealing flange. The blend is solidified to form a solid desiccant layer, and the electronic device is sealed with the enclosure along the sealing flange. Boroson et al., however, do not teach the effect of particle size of these solid particle desiccants on their performance, nor do they teach any benefit of particles smaller than 0.1 micrometers.
It is an object of the present invention to provide a desiccant package which includes a desiccant for protecting highly moisture-sensitive electronic devices sealed within an enclosure.
It is another object of the present invention to provide a desiccant for protecting highly moisture-sensitive electronic devices sealed within an enclosure. This object is achieved by a desiccant comprising solid water absorbing particles of one or more materials, at least one of such materials having an average particle size range 0.001 to 0.1 micrometers to provide a high rate of water absorption and to provide an equilibrium minimum humidity level lower than a humidity level to which the device is sensitive within the sealed enclosure.
These objects are achieved by a desiccant package useable for protecting highly moisture-sensitive electronic devices sealed within an enclosure, comprising:
a) a moisture-permeable container which can be positioned in the sealed enclosure;
b) solid water absorbing particles of one or more materials disposed in the moisture-permeable container;
c) said solid water absorbing particles including solid particles of one or more materials, at least one of such materials having an average particle size range 0.001 to 0.1 micrometers to provide a high rate of water absorption and to provide an equilibrium minimum humidity level lower than a humidity level to which the device is sensitive within the sealed enclosure; and
d) said moisture-permeable container essentially maintains the moisture absorption rate of the solid water absorbing particles contained therein, the moisture-permeable container acting to separate the solid water absorbing particles from the highly moisture-sensitive device.
The present invention provides the following advantages: a moisture absorption rate that enhances the moisture absorption rate of a solid material capable of providing a low equilibrium minimum humidity within the enclosure, by the reduction of said solid material particle size to an average less than 0.1 micrometers; a moisture absorption rate that essentially maintains or enhances the moisture absorption rate of said less than 0.1 micrometer solid water absorbing particles capable of providing a low equilibrium minimum humidity within the enclosure, by a container or binder in which the solid water absorbing particles are contained; simple, fast, and reliable placement of a desiccant layer on an interior surface of a device enclosure; containment of solid desiccant particles by a container or binder within the device enclosure; thermally curable binders provide for removal of moisture trapped in an uncured desiccant layer by thermal curing of the layer; radiation-curable binders provide for fast curing of a desiccant layer by exposure to radiation; forming a desiccant layer on a separate adhesively bondable support or between a water permeable membrane and a separate adhesively bondable support provides for high speed, roll-to-roll manufacturing of a desiccant layer supply; and providing a desiccant layer having relatively low sensitivity of its desiccation efficacy to temperature cycling at elevated temperature up to 150xc2x0 C.

Desiccants and desiccant packages for highly moisture-sensitive electronic devices


A reproducing apparatus with simultaneous parallel processing of different image signals includes a storage device for storing a plurality of image signals supplied sequentially, each of the stored image signals representing a different image. A first structure is provided for reading out image signals stored in the storage device and supplying the read out image signals sequentially to an output terminal. A second structure is provided for separately storing outputting one image signal from among the plurality of stored image signals while image signals are being supplied sequentially from the first structure to the output terminal.

1. Field of the Invention
This invention relates to a reproducing apparatus and, more particularly, to an apparatus for duplicatingly reproducing still images, for instance.
2. Related Background Art
It has been a practice to let a video signal supplied to an apparatus be tentatively stored in a memory and to let a signal read out from the memory be output to a monitor or to a printer.
Heretofore, however, where a memory used for a monitor or printer is also used for other purposes or where separate memories are provided, the contents of such two memories are altered continuously. Therefore, there is a problem in case of printing out data using a printer that an image signal supplied to the apparatus during printing is wasted.
In a different aspect, recently proposed broadcast television systems intended for practical use, aside from the conventional NTSC system with an aspect ratio of 3:4 and a scanning line number of 525, include those of finer resolution, for instance a HDTV system with an aspect ratio of 9:16 and a scanning line number of 1,125. The HDTV system can deal with about five times the image data quantity compared to the NTSC system and also uses a wide screen. Thus, it permits enjoyment of images which are dense and rich in the on-the-spot senser.
However, data quantity has been increased to such an extent that it can not be directly transmitted to each home due to limitations imposed on the broadcast waves and communication capacity. Therefore, bandwidth compression is adopted for transmission on the basis of commonly termed distribution quality, which is slightly inferior to the intrinsic image quality obtained in the studio. Table 1 shows specifications concerning the in studio quality and distribution quality in the HDTV system.
TABLE 1 ______________________________________ In-studio Distribution quality quality ______________________________________ Scanning line 1,125 1,125 number Brightness 30 MHz 20 MHz bandwidth (Y) Brightness 74.25 MHz 48.6 MHz sampling frequency Chromatic 15 MHz 7 MHz difference bandwidth (Pr, Pb) Chromatic 37.125 MHz 16.2 MHz difference sampling frequency ______________________________________
It is thus inevitable to provide distribution quality for home enjoyment of HDTV system images as moving images.
In the meantime, with the HDTV system the scanning line number is large, and the image is dense and less subject to flickering. For this reason, the HDTV system image is enjoyable as a still image rather than as moving images, and utilization of the HDTV system in the fields of art, culture, education and animation has been expected. In the case of a still image, the observer looks at one frame of an image thoroughly in several to several tens of seconds. For this reason, in-studio quality is required as image quality.
Accordingly, a HDTV still image reproduction apparatus permitting enjoyment of in-studio quality is proposed separately from the HDTV distribution quality image reproduction apparatus. FIG. 4 shows a block diagram of an example of such a structure. Reference numeral 10 designates an antenna for receiving signals transmitted from a broadcast satellite, 12 is a HDTV still image reproduction apparatus, 14 is a HDTV color image monitor for displaying images with 1,125 scanning lines. In this still image reproduction apparatus, reference numeral 16 designates a tuner for converting signals received by antenna 10 into still image digital compression data, 18 is a decoder for decoding still image digital compression data obtained by, for instance, bandwidth compression in a DPCM process, into original image data, 20 and 22 are image frame memories each for storing one frame of decoded image data from decoder 18, 24 is a switch for selecting image frame memory 20 or 22 for writing decoded data from decoder 18, 26 is a switch for selecting image frame memory 20 or 22 for reading out stored data, and 28 is a D/A converter for converting image data read out from image frames 20 and 22 into an analog signal.
In this still image system, signals intercepted by antenna 10 are converted by tuner 16 into digitally compressed data, which is then decoded by decoder 18. Decoded data from decoder 18 is written in alternate image frame memories 20 and 22 under control of switch 24, and data read out from image frame memories 20 and 22 are supplied to D/A converter 28 and printer 13 alternately under control of switch 26. In other words, switches 24 and 26 function such that decoded data is written in one image frame memory (for instance 20) while stored data is read out from the other image frame memory (for instance 22).
As to the transmission rate, since one still image frame is observed in several to several tens of seconds, it is usually about 2 Mbps for saving the transmission bandwidth (here the bit rate of the transmission).
In the still image system, if it is desired to obtain a hard copy of the received image on a recording sheet or the like using printer 13, during transfer of data to printer 13 one of the image frame memories 20 and an 22 is occupied, and image from the other image frame memory can not be observed on monitor 14.

Reproducing apparatus with simultaneous parallel processing of different image signals


A system and accompanying method for Digital Rights Management (DRM) are disclosed that permit arbitrary forms of digital media to be vended in a networked environment. Special purpose renderers are distributed with each particular instance of digital media. Each renderer may include a tailored set of controls allowing the owner of the digital media to restrict the use thereof.

Digital media includes software, music, movies, literature, and other forms of digital content. The digital media industry and other digital media owners that distribute digital media have implemented business models that rely on their ability to collect a fee from consumers for each copy or use of a digital work. Presently, once initial distribution of the media has occurred, the unauthorized reproduction or piracy by consumers of the digital media, which is often protected by copyright, constitutes a threat to the viability and profitability of the digital media industry.
Therefore, the digital media industry has begun implementing Digital Rights Management (DRM) or digital restriction management, as it is less frequently referred, to manage and enforce particular controls and restrictions associated with the use of digital media. Existing DRM solutions including content scrambling systems, hardware dongles, product activation, and digital watermarking have proven ineffective. Therefore, a need exists for providing DRM of digital media that allows the controlled or restricted rendering of arbitrary forms of digital content, where the controls and restrictions are flexible and definable by the media owner.

This patent is subject to a terminal disclaimer.

System and method for digital rights management of digital media


A driving simulation system is configured to train a driver. The system includes a simulated driver cockpit which includes a steering wheel and at least one video display providing a simulated driving environment to the driver. The system further includes a computerized simulation control module including programming configured to operate a driving simulation through the simulated driver cockpit. The driving simulation includes driving rules. The programming is further configured to monitor performance of the driver during the driving simulation, compare the performance of the driver to the driving rules, and while the driving simulation is still in operation, provide untextualized feedback to the driver regarding performance of the driver.

The statements in this section merely provide background information related to the present disclosure. Accordingly, such statements are not intended to constitute an admission of prior art.
Driving simulators are known in the art. Such simulators include limited programming to discern whether the driver passes certain minimum skill criteria. Driving simulators can include standard driving rules such as speed limits and collision indications. Scoring indications can be provided, for example, rating the driver as having a percentage grade.


A material for dewatering elements at the wet end of a paper-making machine is disclosed. The material comprises an elastomeric polymer matrix, and a filler added to the matrix at a level of 10 to 50 percent by weight, and the material has a hardness according to Shore A between 60 and 85. The invention also relates to a dewatering element comprising such material, and to the use of such material for the preparation of a dewatering element.

In the wet end of a paper-making machine a forming screen or wire, supporting a slurry of cellulose fibers in water together with chemicals and pigments, slides over a number of dewatering elements which promote drainage of water from the slurry. Such dewatering elements include a forming board, foil blades, vacuum blades, suction box covers etc. The effluent water removed from the slurry through the forming screen typically contains about 0.5 to 1 percent of solid material. This solid material typically includes about 95 percent pigments (e.g. calcium carbonate) and about 5 percent cellulose fibers.
Hence, the forming screen sliding over these dewatering elements is subjected to extensive wear resulting from the sliding itself and from the presence of these pigments and cellulose fibers in the effluents. The forming screen, generally a polyester fabric, therefore has to be replaced for example every 30-35 days at a very high cost. Wear on the forming screen is particularly pronounced when the screen slides over the flat suction box covers, at which point the amount of effluent water has already been significantly reduced. Flat suction box covers are usually made of very hard ceramic materials, such as aluminum oxides, chromium oxides, zirconium oxides, silicon carbide or silicon nitride. The nature of such materials, including their surface roughness, porosity and pore size plays an important role in the wear of the forming screen, to a similar extent as the type and characteristics of the pigment in the water effluents (see for example M. Laufmann and H. U. Rapp, Wochenblatt für Papierfabrikation, 114/16, 615-622 (1986)).
The hard ceramic covers are vulnerable as they are subjected to accidental impact damage, stress cracking, thermal shock damage and sharpening under screen contact. Typically, their manufacturing costs are also very high as they consist of an assembly of small, 30 to 60 mm long individual elements which are glued together on the flat suction box, leaving small voids where pigment particles from the water effluent can accumulate. The retention of these pigment particles further accelerates the wear of the forming screen or wire.
Hence, there is a problem in the prior art relating to the wear on the forming screen at the wet end of paper-making machines due to the sliding of the screen over dewatering elements, and the associated high cost of the screen replacement. Moreover, there is a problem related to the vulnerability of the prior art ceramic materials.
GB 1 526 377 discloses dewatering elements having inserts made from polyurethane cast in situ and which are subsequently machined to the desired final shape. The preferred polyurethanes for use according to said patent are referred to-as having excellent hardness and abrasion properties, where the polyurethane has hardness values preferably in the range 93 Shore A to 96 Shore A. Minor amounts of fillers may be added to the polyurethane. As an example, the polyurethane "Adiprene L 167" is mentioned, which is a composition having a hardness of 95 Shore A. A small amount of green pigment is added to the composition.


A control module includes a plurality of switching elements, a control chip, and an identification unit. The switching elements are connected to a power terminal through a corresponding resistor each, wherein the resistances of corresponding resistors or equivalent resistance of combination thereof are different. The switching elements generate an input current according to operating conditions thereof. The input current is sent to the control chip through an input/output terminal and is transformed to a digital value. The identification unit identifies the operating conditions of the switching elements according to a lookup table and the digital value, such that the control chip executes a corresponding logic operation.

1. Field of the Invention
The invention relates to identification of operating conditions of switching elements by a single terminal, and in particular to methods and devices for identification of operating conditions of switching elements by a single terminal utilized in control panels of consumer electronic devices.
2. Description of the Related Art
Due to advances in semiconductor technology, chip design has become more complex, with density of logic gates increases accordingly. Integration of function of multiple conventional chips into one chip, system on chip (SOC), cost is increased accordingly due to an increase in chip area. Moreover, inputs and outputs between modules become more complex. As input/output pins increase, costs of chip fabrication and package and complexity of further chip testing are increased.
FIG. 1 shows a conventional control panel 100. As shown, each switching element 12 is coupled to an input/output terminal (pin) 14 of the control chip 10. Accordingly, operating conditions of each switching elements is input to the control chip 10 through the corresponding input/output terminal 14. As chip area increases with addition of input/output terminals 14, cost is increased accordingly. Thus, a decrease in input/output terminals of chips is needed to lower cost.

Control module, related control chip and identifying method thereof


A tool is set forth defined by elongate main body with a forwardly positioned leg defined by a central bore directed through the main body and forward leg, with an enlarged cylindrical knurled handle mounted rearwardly of the main body for securement thereof for positioning interiorly of an individual's mouth cavity. The tool is geometrically configured to enchance comfort and use in its application within the cavity. A modified configuration of the invention includes a fiber optic cable superimposed within an overlying chamber mounted coextensively with the main body and forward leg, wherein the main body and forward leg extend to the forward terminal end of the forward leg to enhance viewing interiorly of the mouth cavity. A further modified configuration of the instant invention includes a valve positioned to the main body and formed with a reciprocating blade to enable manual modification of vacuum directed through the tool. The invention further contemplates the use of spaced grommets mounted on the forward leg to enhance positioning of the forward leg interiorly of the mouth cavity.

1. Field of the Invention
The field of invention relates to surgical suction tools, and more particularly pertains to a new and improved surgical suction tool wherein the same is configured for enhanced use and positioning within an individual's mouth cavity to include means to enhance positioning within the mouth cavity, as well as optional illumination means to provide illumination within the mouth cavity.
2. Description of the Prior Art
The use of suction tools for positioning within a mouth cavity is known in the prior art for the removal of saliva, liquid, and various debris from the mouth cavity, such as in use during a dental procedure. Examples of the prior art include U.S. pat. no. 3,557,456 to Hutchinson providing a suction tool formed with a tapered lower end to provide clearance for access of dental tools within the mouth cavity.
U.S. pat. no. 2,504,557 to Lumian sets forth a suction tool formed with a "U" shaped forward leg and formed with a series of passages formed through a forward tip of the leg for direction of fluid therethrough.
U.S. pat. no. 3,885,312 to Nordin sets forth a saliva extractor wherein a plurality of tubes are configured for a partial telescoping relative to one another for enhanced positioning within a mouth cavity.
U.S. pat. no. 2,574,135 to Ward sets forth a saliva vacuum tool formed with a forward slotted tip to provide enhanced access of the saliva interiorly of the vacuum bore of the tool.
U.S. pat. no. 2,859,518 to Cohn sets forth a vacuum tool for use in a dental procedure wherein the tool includes a lower clamp to impose pressure upon an exterior surface of the jaw of an individual for enhanced securement of the tool interiorly of an individual's mouth.
As such, it may be appreciated that there is a continuing need for a new and improved surgical suction tool wherein the same addresses both the problems of unique configuration for positioning in a combination of a myriad of individuals in a dental procedure, as well as convenience in its application and in this respect, the present invention substantially fulfills this need.


An image processing apparatus obtains segment definition information that defines a plurality of segments obtained by dividing a human body along a body axis, and obtains a three-dimensional image including a plurality of slice images indicating cross sections of a subject. The image processing apparatus identifies, based on the segment definition information, a segment to which a cross section corresponding to at least one slice image among the slice images included in the image belongs, and calculates a coordinate value of the at least one slice image, based on the identified segment and a reference coordinate system in which a coordinate value is defined for each of the segments.

In the medical field, diagnoses are performed using three-dimensional images obtained by various image capturing devices (modalities) such as computed tomography devices (hereinafter referred to as CT devices). In particular, to capture changes in the state of a subject over time, images captured at different points in time are compared. The images can be easily compared by displaying a slice in one of the images and a slice (hereinafter referred to as a corresponding slice) in another image, both slices including substantially the same anatomical structure, side by side. The term "slice" refers to an image for a cross section extracted from a three-dimensional image. To facilitate comparison of images, each slice in one of the images to be compared is associated with the corresponding slice in the other image in advance, the images being captured at different points in time. The term "aligning", as used herein, refers to the act of associating each of slices constituting a three-dimensional image with a slice or slices (a corresponding slice or slices) in another or other three-dimensional images including substantially the same anatomical structure as the anatomical structure of the slice.
A plurality of images are used for a diagnosis, and each of the images often has a large number of slices (several hundred or more). If individual slices are aligned manually, a heavy load may be imposed on the operator.
In light of the issue described above, PTL 1 discloses a method for aligning images captured at a plurality of points in time by using a reference coordinate system having coordinate values, each of which is related to an anatomical position, such that even when three or more images are to be compared, the images can be easily aligned. However, if images to be aligned have different balances of sizes of an anatomical structure between anatomical positions, slices having the same coordinate value in the reference coordinate system may not be located at corresponding positions in the images. One method to address this issue is also disclosed in PTL 1. In the disclosed method, a plurality of coordinate systems are created in accordance with the sizes of anatomical structures (by bone structure, age, height, sex, and so on), and a suitable coordinate system is selected for each image being processed to achieve more accurate alignment.

Image processing apparatus, image processing mehod, and storage medium


A memory device includes a cell array including a memory cell that includes a variable resistance element, a reference resistor configured to provide a resistance varying according to an adjustment code, and a read circuit configured to read data that is stored in the memory cell, based on a resistance of the variable resistance element and the resistance of the reference resistor. The memory device further includes a reference adjustment circuit configured to obtain a first calibration code corresponding to a temperature variation, and a second calibration code corresponding to a process variation, and perform an arithmetic operation on the obtained first calibration code and the obtained second calibration code, to obtain the adjustment code.

The inventive concept relates to a memory device, and more particularly, to a memory device including a variable reference resistor and a method of calibrating the variable reference resistor.
A resistive memory device may store data in a memory cell including a variable resistance element. To read the data stored in the memory cell, a resistance of the variable resistance element may be determined by providing a read current and/or a read voltage to the memory cell and detecting the read current and/or the read voltage. The data stored in the memory cell may be determined based on the resistance of the variable reference resistor and a resistance of a reference resistor. Resistive memory devices may be affected by variations in process, voltage, temperature, or the like, and compensating for such variations affect the operational reliability of the resistive memory devices.

Memory device including variable reference resistor and method of calibrating the variable reference resistor


Dual display control device and method using an RGB interface are provided. A dual display control device controlling a first display device and a second display device using an RGB interface includes: a synchronization signal output unit that outputs vertical and horizontal synchronization signals to the first display device and the second display device; and a data output unit that outputs first data to the first display device in a first section of a first pixel clock and outputs second data to the second display device in a second section of a second pixel clock, in accordance with the vertical and horizontal synchronization signal via a data line shared by and connected to the first display device and the second display device. Accordingly, it is possible to reduce the number of signal lines, thereby embodying an efficient hardware configuration.

1. Field of the Invention
The present invention relates to a display control device, and more particularly, to dual display control device and method using an RGB interface.
2. Description of the Related Art
With the development of electronic apparatuses, a display device outputting data and images has been used in various electronic apparatuses. For example, a display device mounted on a personal computer or a mobile device outputs an image by an internal signal process and in response to a signal operated by a user interface.
According to the related art, various interface systems which can be replaced for an existing CPU interface system have been developed with the recent enlargement of a displace screen. In the CPU interface system, CS (Chip Select) pins are divided and the other control signals (RS, WE, RE, and the like) and data signals are shared, whereby the CS pin corresponding to a desired display device and image data is transmitted via the shared other signal lines. However, in the display system using an RGB interface, only one display device is controlled to display an image. Here, control signals and data signals should be separated and independent interfaces therefor should be provided to support dual display. Therefore, in the RGB interface system, there are various problems with the complexity of circuitry and the increase in cost for supporting the dual display.
FIG. 1 is a block diagram illustrating the configuration of a dual display system using an RGB interface according to the related art. Referring to FIG. 1, the dual display system includes a controller 110, a first display controller 111, a second display controller 112, a first display device 121, and a second display device 122. As shown in FIG. 1, the first display controller 111 outputs a pixel clock PCLK1, vertical and horizontal synchronization signals Vsync1 and Hsyn1, and a data signal Data1[0:24] to the first display device 121 to control the first display device 121, and the second display controller 112 outputs a pixel clock PCLK2, vertical and horizontal synchronization signals Vsync2 and Hsync2, and a data signal Data2[0:24] to the second display device 122. In this system, since the hardware circuit design is complex and plural display controller 111 and 112 should be provided, there is a problem with an increase in cost.

Apparatus and method for controlling dual display device using RGB interface


The electron beam device includes a source of electrons and an objective deflector. The electron beam device obtains an image on the basis of signals of secondary electrons, etc. which are emitted from a material by an electron beam being projected. The electron beam device further includes a bias chromatic aberration correction element, further including an electromagnetic deflector which is positioned closer to the source of the electrons than the objective deflector, and an electrostatic deflector which has a narrower interior diameter than the electromagnetic deflector, is positioned within the electromagnetic deflector such that the height-wise position from the material overlaps with the electromagnetic deflector, and is capable of applying an offset voltage. It is thus possible to provide an electron beam device with which it is possible to alleviate geometric aberration (parasitic aberration) caused by deflection and implement deflection over a wide field of view with high resolution.

A scanning electron microscope (SEM) using an electron beam which is used to observe, inspect and measure a sample accelerates electrons emitted from an electron source and irradiates the electron so as to be converged on a surface of the sample using an electrostatic or electromagnetic lens. The electrons may be called as primary electrons. When the primary electron is incident, secondary electrons or reflection electrons may be generated from the sample. The secondary electrons or the reflection electrons are detected while scanning the electron beam so as to be deflected to obtain a minute pattern on the sample or a scanning image of composition distribution. Further, electrons which are absorbed onto the sample are detected to form an absorbed current image.
As a desirable function of the scanning electron microscope, there is a function of performing scanning with a wide viewing field without causing the significant lowering of a resolution of the electron beam. As the miniaturization of a semiconductor is progressed, a two-dimensional high speed inspection of a resist pattern is required and scanning with a wide viewing field is required in order to expand an inspection area and lower a shrinkage.
In order to achieve the above object, it is required to reduce a deflected chromatic aberration which is generated by the deflection of the electron beam. As an implementing method thereof, Patent Literature 1 and Patent Literature 2 suggest to use an electron optical element represented as E×B in which an electromagnetic deflector and an electrostatic deflector are combined. The E×B element is also used as a part of an energy filter of the electron beam or a deflecting element of the secondary electrons, which is disclosed in Patent Literature 3, Patent Literature 4, and Patent Literature 5 and Non-Patent Literature 1.


There is disclosed a global positioning system receiver method and system which converts the analog signals to digital signals prior to performing signal acquisition and GPS unique processing functions. The A/D converter uses full null zone processing to increase anti-jamming capability and 4-level output to reduce signal processing. A single analog and digital channel is used for both the L1 and L2 channels as well as for all P(Y)-code and C/A-code thus allowing full multi channel tracking with several channels each tracking a separate signal while the remainder of the channels rove over all of the signals on the alternate L-band with programmable duty cycles. The system allows for Y-code substitution for P-code by multiplexing a portion of the Y-code generated between multiple channels.

The Navstar Global Positioning System (GPS) is used to determine exact geographic position (i.e., latitude, longitude and height above the earth) absolute velocity, as well as the exact time. The navigation device, receiver, must calculate the position velocity and the time by determining distance and relative velocity to a series of satellites. The velocity of the receiver is calculated from the doppler frequency shift of signals transmitted from space while the exact position of the receiver is calculated from the time shift of data due to the distance the signals must travel from the satellite. This distance is called range and the doppler shift yields range rate.
A GPS receiver must receive signals generated from a satellite about 11,000 miles away. A GPS satellite transmits about 6 watts spread spectrum signal. The satellite and receiver, employ spread spectrum techniques to differentiate the signal from the noise. "Spread spectrum" means that as time passes, the frequency at which a signal is being transmitted will change or the instantaneous phase at which the signal is being transmitted will change. Using correlation techniques, the satellite receiver can match the spread spectrum signal coming from the satellite with an image of the signal that the receiver attempts to estimate. A precise match of the satellite's spread spectrum signal produces a potential signal processing gain of up to 53 decibels. The use of spread spectrum techniques is essential to receive 6 watts of energy transmitted 11,000 miles away. At the antenna, the GPS signal is about 20 dB below ambient cosmic noise.
Using the GPS system, four transmitting satellites are required, to solve for the three spatial dimensions and time. The basic method of determining position is knowing the time difference from each of the satellites. The time difference for each satellite is the time required for a signal initiated at the satellite to be received by the user. Therefore, at least four satellites must be tracked. This is accomplished ideally by the use of at least four hardware receiver channels.
Classically and historically, receiver channels have been large, power hungry and expensive. While this gives the best performance, it costs a lot of money. The lowest cost approach uses sequential tracking. Under sequential tracking, there is one receiver channel that sequences across multiple satellites--tracking each satellite for a predetermined period of time, and then tracking another satellite, etc. Sequential tracking requires the minimum hardware, but also has the lowest performance characteristics.
There has been developed a multiplex technique which was essentially a compromise between using four receiver channels and using purely sequential tracking. This technique sequences very quickly across four satellites. This provides the dynamic capability of a continuous track receiver, but has a serious signal strength penalty under jamming conditions. The present state of the art requires a choice between either large and expensive receivers for high performance, or small and more affordable sequential tracking, with a severe compromise in performance.
Therefore, a need exists for a receiver that is small and affordable, yet with no compromise in performance.
A further need exists in the art for a GPS receiver that achieves enhanced performance under diabolical conditions, such as jamming and fast acquisition.
A still further need exists in the art for a receiver having simultaneous C/A and P or Y-code (P(Y)-code) capability while reducing the parts count and enhancing signal acquisition time.

System and method for a digital navigation satellite receiver


A latch arm for engaging with a corner portion of an IC is pivotably supported on a corner portion of a base member of an IC carrier or IC socket. A spring element extends from a rear end of the latch arm, and is bent to accumulate resilient force when the latch arm is pivoted upwardly to remove engagement. Thus, the latch arm is pivoted in the engaging direction by the accumulated resilient force, in order to maintain engagement with the IC.

1. Field of the Invention
This invention relates to an IC carrier for carrying thereon an IC for transportation or to be received in an IC socket. From another aspect, the present invention relates to an IC socket to be used for connection to an IC, and particularly to an IC holding construction which is common both to the IC carrier and the IC socket.
2. Brief Description of the Prior Art
U.S. Pat. No. 4,881,639 owned by the present applicant discloses a one-piece type IC carrier comprising a base member and torsion bars each integrally formed on each corner of the base member, and latch arms integral with the torsion bars, respectively and adapted to engage with an edge portion of an IC placed on the base member.
In this one-piece type IC carrier, each latch arm is pivoted upwardly about its corresponding torsion bar to remove its engagement with the IC. At this time, a twisting energy is accumulated in the torsion bar, and the latch arm is pivoted downwardly by this twisting energy so as to be brought into engagement with a corresponding corner portion of the IC.
The above carrier is operated to open and close the latch arms while exerting a twisting force to the torsion bars, so that the latch arms are engaged with and disengaged from the IC. Since the twisting force is repeatedly exerted to the torsion bars every time the IC is inserted and removed, the twisting stress is concentrated on connecting portions at both ends of the torsion bars which are integrally connected to the base member. As a result, the connecting portions gradually become fragile and unable to fully carry out their functions. Moreover, since the torsion bars are required to extend across the corner portions of the base member which has only a limited space, it is difficult to obtain a sufficient length for each of the torsion bars. Therefore, the connecting portions of the torsion bars tend to be more fragile and have a tendency to break. In addition, when the torsion bars and the latch arms are integrally formed in the base member, complicated narrow spaces or gaps for defining both of them must be formed therearound, and therefore, molding is not easy.
As described above, in the IC carrier or IC socket of the type in which the above latch arms are elastically engaged with and disengaged from the IC, the latch arms are integrally formed on the base member such that the latch arms themselves are elastically shifted at the connecting portions, for example, at the above torsion bars, with respect to the base member.
On the other hand, if the latch arms are formed separately from the base member to form a two-piece construction, the latch arms are pivotably supported relative to the base member through shafts or pins respectively, and the latch arms, when pivoted to positions for engagement with the IC, are brought into engagement with the base member through male and female engagement means in order to hold the IC. Such an IC engagement means as just mentioned can obviate problems such as deterioration in elasticity and breakage of the latch arms, the problems being inherent in the one-piece construction. However, the engagement between the male portion and the female portion is not reliable, and they are easily disengaged due to wear of the male and female portions.

IC accommodation apparatus having retaining latches


The invention may be embodied in a resynchronizing, push-pull drive circuit for driving the gate electrodes of a digital Class-S Radio Frequency Power Amplifier (RF-PA). A binary bitstream received from a bitstream generator, such as a sigma-delta modulator, Viterbi-based optimal-bit-pattern modulator sigma-delta, or other suitable modulator, is resynchronized to a low-jitter master clock, then converted to fast-rise, high-swing complementary digital signals to drive the gates of the Class-S RF-PA. The drive circuit provides a high slew-rate, large-swing, quasi-digital gate drive circuit to drive the significant gate capacitance of the RF-PA with sufficient rise times. A combination of bipolar transistor current switches and cascoded CMOS devices is employed to attain requisite performance. For example, the driving circuit is well suited for use with Class-S RF-PAs used in wireless communication systems.

Digital Class-S Radio Frequency Power Amplifier (RF-PAs) employ a spectrally shaped bitstream to switch the output stages in binary fashion. In operation, a bitstream generator, such as a sigma-delta modulator or Viterbi-based optimal-bit-pattern modulator, encodes an input baseband signal into a digital pulse stream in which the information-bearing baseband signal is frequency-translated to a desired carrier frequency. Simultaneously, the encoding process shapes quantization noise, assuring that it is greatly attenuated in the vicinity of the carrier frequency and pushed out-of-band, where quantization noise can be removed by bandpass filtering.
The bitstream drives the gates of a push-pull switch-mode final stage, through a level shift gate driver. The output of the final stage passes through a bandpass filter (BPF) to recover the modulated RF signal and to eliminate the out-band quantization noise.
Gate driving of the Class-S RF-PA is not amenable to conventional medium/narrow bandwidth RF matching techniques, as efficient final stage switching requires fast gate voltage rise times on the order of less than 50% of the bitstream generator's clock period and hence essentially a pulse drive capable of driving the input (gate) capacitance of the Class S amplifier's output stage.
One approach to gate-driving employs a current-steering long-tailed pair having low-valued collector/drain loads coupled directly to the gates of the driven transistors, but suffers problem of high power dissipation. Yet another approach to gate driving employs complementary class-AB type emitter followers in a totem-pole arrangement. This architecture is subject to the well-known instabilities exhibited by emitter followers when driving capacitive loads. Alternatively, high-speed CMOS output buffers may be employed, but are subject to breakdown limitations characteristic of thin-oxide narrow-gate length transistors.
There is, therefore, a continuing need for improved electronic circuits for driving the electrodes of Class-S RF-PAs. More particularly, there is a need for gate driving circuits with sufficiently fast rise times for driving the significantly capacitive load of the gates of the input transistors of the RF-PA with improved power consumption and stability characteristics.

BiCMOS gate driver for class-S radio frequency power amplifier