A port cannula for puncturing implantable or implanted port catheters includes a cannula tube with a ground surface, which is formed from a ground cut inclined with respect to a center axis of the cannula tube by a ground-cut angle and from two facet cuts lying at an angle to each other, and of a cannula tip which is provided by the ground surface and which is oriented via a first bend in the direction of the center axis of the cannula tube. The ground cut and the facet cut are adapted to each other in such a way that, on the one hand, during puncturing, a bending of the cannula is least reduced and, on the other hand, the pain caused to the patient is kept within an acceptable range.

Known cannulas (or puncture cannulas) for puncturing or piercing have a more or less strongly inclined wedge-shaped ground surface at an end portion of the cannula. The rear edge of the wedge-shaped ground surface forms a sharp blade. During the puncturing, a blade of this kind has the effect that constituent parts are punched out from the material that is to be pierced. When puncturing tissue for example, this is undesirable on account of the trauma caused. Moreover, the punching-out effect proves extremely undesirable if cannulas of this kind are used to puncture implantable port catheters. Such port catheters generally consist at least of an implantable capsule which has a hollow space for the removal and/or administration of a liquid such as blood, blood components or a medicament. The capsule is connected to a catheter that opens into a vessel or other treatment site. The wall of the implanted capsule directed toward the skin of the patient is provided in the form of a pierceable elastomer membrane, which is pierced by the cannula through the skin. The penetration of a cannula into the membrane of a port catheter causes leaks, since the rear edge of the ground surface punches elastomer material out of the membrane. This results in the formation of holes, which can no longer automatically close under the restoring force of the membrane material. This has the effect that the implanted capsule begins to leak after just a few piercing procedures. Moreover, punched-out elastomer particles can be carried off into the patient or can block the catheter.
The European patent EP 0 495 214 B1 describes a port cannula which can effectively reduce punching-out. The content of said document is incorporated in full, by reference, into the present application. The cannula described in said document is such that the blade formed by the rear edge is substantially concealed by the cannula tip and in this way can no longer cut. This is achieved principally by the fact that the cannula tube is bent laterally toward the piercing part and, in its further course, is hook-shaped and has a lumen opening ground tangentially into the concave recess of the hook-shaped tube, which lumen opening forms, at its rear edge, a blade that is strongly oriented inward on account of the design of the tube. The demands placed on a port cannula are substantially met by the port cannula described in EP 0 495 214 B1.

Port cannula for the puncturing of port catheters


A fixing device thermally fixes an image developed on a recording sheet. The fixing device includes: a heating roller heated by a heat source and having a first end side and a second end side with respect to an axial direction; a power supply member for supplying the heat source with power for use in heating the heating roller; a first bearing formed of a conductive material, attached to the first end side of the heating roller and connected to a ground; and an second bearing formed of an insulating material and attached to the second end side of the heating roller. The power supply member is disposed at the second end side of the heating roller.

An image forming apparatus, such as a laser printer, is generally includes a fixing device for thermally fixing an image transferred to the sheet from a photosensitive element. JP-A-8-48432 discloses a fixing device including a heating roller heated by a heat source, a pressing roller pressed toward the heating roller, and a bearing that rotatably supports the heating roller and that is formed of a conductive resin. According to this device, an earth plate is connected to the bearing formed of conductive resin, thereby allowing electric charges accumulated in the heating roller to be discharged. Depending on the structure of the fixing device, there is a case where a conductive member for supplying power to the heat source and a power supply member having a thermal fuse as a safety device are disposed in the vicinity of the bearing of the heating roller.
However, in a case where the bearing is formed of a conductive resin and the power supply member is disposed in the vicinity of the bearing, when the bearing has become fused as a result of occurrence of a failure in temperature control of the heating roller, the fused bearing may contact the power supply member. When the bearing contacts the power supply member as mentioned above, a short circuit arises between the power supply member and the heating roller by way of the conductive bearing. This may eventually result in infliction of damage on the fixing device.

Fixing device for thermally fixing an image developed on a recording sheet and use with an image-forming apparatus


A shielded semiconductor chip carrier having a high-density external interface includes conventional printed circuit boards having plated through holes for achieving shielding of the contacts of the matrix. Two fork type connectors have molded about the distal ends thereof an annular ring of dielectric plastic material, and fork type connectors are press fit into each plated through hole, thereby locking the electrical contact within the shield formed by the plated through hole. The resulting connector provides a high-density contact matrix with each connector being electrically shielded along substantially its entire length.

1. Field of the Invention
The present invention relates to a semiconductor chip or die carrier having a reduced size and, more particularly, a semiconductor die carrier affording an external interface having a high-density of electrically conductive contacts concentrated within a very small area and designed to shield the interconnection between the electrical contacts.
2. Description of the Related Art
Semiconductor packages typically contain a semiconductor die having bonding pads formed thereon, a plurality of leads connected to the bonding pads of the semiconductor die, and insulative packaging material formed around the semiconductor die and inner portions of the leads. Such a semiconductor package allows the transmission of electrical signals between the semiconductor die and an interface surface, such as a printed circuit board (PCB), via the bonding pads of the semiconductor die, and electrically conductive pads between the bonding pads and the leads, the leads themselves, and traces on the interface surface.
In the prior art, various methods are known for providing the electrically conductive path between the semiconductor die and the leads of the semiconductor package. Such methods, commonly referred to as bonding techniques, include C4 (controlled collapse die connection) bonding, wire bonding, and TAB (Tape Automated Bonding).
Conventional semiconductor packages suffer from many deficiencies. Conventional PGA (Pin Grid Array) packages, for example, tend to take up large amounts of circuit board area. Indeed, PGA packages generally increase significantly in size as more input/output interconnections are needed, suggesting that future PGA packages for microprocessors will take up even more board area than existing PGA packages.
The manner in which conventional C4 and other bonding technologies are currently being used contributes to the aforementioned area usage problem. For example, in C4 technology, the interconnections provide useful electrical connections, but do not provide an adequate amount of mechanical strength for the types of leads now in use. Moreover, C4 connections are not typically applicable for use within pluggable semiconductor packages. Consequently, in the assembly of PGAs, manufacturers who use conventional C4 bonding technology require that the portions of the leads extending externally from the PGA must be spaced apart to a significant extent. Of course, such spacing increases the area of the PCB that will be occupied by the PGA. Moreover, the use of a multi-layer conductor for supporting the semiconductor die within the PGA package also adds to the size and cost of the PGA package. Furthermore, conventional C4 bonding technology can result in problems with individual lead parasites, inspectability and testing problems, and problems relating to touch-up and repair of the connections.
In addition to increasing the size of conventional PGA-type semiconductor packages, the use of leads that are intentionally spread apart to compensate for mechanical insufficiencies and to allow for pluggable and/or non-pluggable mounting, and the use of multi-layer conductors for supporting the semiconductor die within such packages, all contribute to deficiencies associated with conventional PGA-type semiconductor packages. These deficiencies include a lengthening in the amount of distance that electrical signals must travel within the semiconductor package, which lengthening affects signal propagation times; an increase in the amount of noise imparted to such electrical signals; an elevation in the power requirements for the semiconductor package; and an increase in the complexity of processes required to manufacture the semiconductor package.
Another problem associated with conventional PGA-type semiconductor packages is that such packages, when not used with a socket, are commonly mounted on PCBs using conventional plated-through hole technology. This necessitates the performance of a soldering step, and such mounting technique increases the complexity and expense of the manufacturing operation. Of course, the use of solder strictly limits upgradability of the assembly, thereby making it difficult to replace components.
The cost of the ceramic packaging material and brazed pin assembly is another disadvantage of PGA-type packages. In addition, such packages have low-performance heat sink characteristics, and such packages are costly to manufacture because they include an excessive number of manufacturing processes.
Another problem associated with conventional semiconductor chip carriers relates to electrical interference. As the speed of microprocessors and other electrical components increases, and as the airwaves are filled with all different types of spurious electrical signals coming in from different sources, the requirement for shielded connectors becomes acute. A shielded connector is similar to a coaxial connector wherein a central pin is surrounded by an insulated material, such as Teflon®, and the Teflon® is surrounded by a gold-plated cylindrical member which, in turn, is surrounded by plastic and with interconnecting means being provided for connecting the coaxial connector components. In a semiconductor chip carrier, it is desirable to have both high-density, as well as individual shielding of each contact.
From the foregoing, it can be understood that conventional semiconductor packages, such as PGA-type packages, take up large amounts of board space. In addition, they are frequently not removably pluggable, and are not easily tested in the field or during manufacture. It is common that such conventional semiconductor packages experience greater amounts of noise and have increased power requirements due to the long distances signals must travel within such packages. Usually, in conventional semiconductor packages, the space occupied by the entire package is many times greater than the space actually required for the semiconductor die.
U.S. Pat. No. 6,577,003 which issued to Crane, Jr. et al. on Jun. 10, 2003 discloses a semiconductor chip carrier affording a high-density external interface. The disclosure of U.S. Pat. No. 6,577,003 is incorporated herein by reference. Although high density is achieved in the chip carrier of U.S. Pat. No. 6,577,003, the electrical contacts of said chip carrier are not shielded.
As a result of the foregoing deficiencies incurred in semiconductor packaging technology, the latter is not sufficient to meet the needs of existing and/or future semiconductor and computer technology. Semiconductor packaging technology has already failed to keep pace with semiconductor die technology and, as computer and microprocessor speeds continue to climb, with greater interference surrounding such packages, and with space efficiency becoming increasingly important, semiconductor packages having even smaller area requirements will be required, and such semiconductor packages must be suitably shielded.

Shielded semiconductor chip carrier having a high-density external interface


A residual gas sensor, suitable for mounting within an low pressure chamber, includes an array of quadrupoles formed from a plurality of parallel rods mounted in a cantilevered fashion in a glass seal. Sixteen parallel rods form an array of nine quadrupoles with adjacent quadrupoles sharing adjacent rods. A filament emitting electrons ionize gas molecules present in the low pressure chamber. These ions enter channels in the center of each quadrupole and are accelerated towards a collector having a surface mounted within each channel of each quadrupole. Voltages are applied to the rods thereby creating an identical electric field within the channels of each quadrupoles of the array. By varying the voltages applied to the rods, the electric field within the channels can be tuned to permit only ions having a specific mass-to-charge ratio to make contact with the collector. By analyzing the current generated by the ions making contact with the collector at different voltages, the presence and quantity of gases present in the low pressure chamber can be determined.

1. Field of the Invention
The present invention generally relates to quadrupole array based residual gas sensor and, in particular, is concerned with a residual gas sensor which utilizes a miniaturized quadrupole array to sense the presence of certain gases within low pressure chambers and a process for manufacturing the same.
2. Description of the Prior Art
Quadrupole residual gas sensors are well known in the art and are used for detecting the presence of specific gases within a chamber in near vacuum conditions, e.g., at pressures of 1.times.10.sup.-5 Torr or below. The typical prior art quadrupole residual gas sensor includes four parallel rods, with equal lengths, precisely arranged and mounted on a ceramic base in a square configuration, thus forming a quadrupole, with an open area, or channel, at the center and extending the full length, of the rods. An electron source generates electrons at one end of the quadrupole which collide with, and ionize, some of the remaining gas molecules in the chamber. Some of these ions are then accelerated through the channel toward a collector positioned at the other end of the quadrupole. The ions that impact upon the collector generate a voltage potential upon the collector proportional to the number of ions and thus proportional to the population of gas molecules within the chamber. When the collector is connected to external circuitry, a current, proportional to the amount of ions impacting upon the collector is thereby generated.
Voltages are induced on the four parallel rods comprising the quadrupole. These voltages are tuned to generate an electric field in the channel between the four rods which permits only ions with a specific mass-to-charge ratio to travel the full length of the channel to the collector. Ions with other mass-to-charge ratios are pulled by the electric field from the channel to one of the four parallel rods and neutralized. Hence, by tuning the voltages on the rods for different mass-to-charge ratios, and by analyzing the current generated by ions impacting on the collector at these voltages, the quadrupole can be used to detect the presence of different gases within a chamber under low pressure or near vacuum conditions. The ability to sense these gases is important for such applications as thin-film deposition in semiconductor device processing as the presence of a specific gas in a near vacuum chamber during thin-film deposition may result in ruined devices.
For a quadrupole residual gas sensor to be able to operate in the above manner, the rods comprising the quadrupole must be precisely mounted with each of the rods parallel to each other and exactly located in the square quadrupole configuration. Heretofore, these rods have been mounted in holes precision drilled in a ceramic base. To achieve sufficiently precise positioning of the rods, as well as to maintain the low pressure integrity of the sensor, the holes typically have to be machine drilled to extremely low tolerances, e.g., 0.2 mil. The rods must then be precisely positioned within these holes in the ceramic base in the parallel, quadrupole configuration. The rods are typically secured to the ceramic base by either nuts or screws which must be precisely tightened to exact torque measurements to avoid any shifting of the rods from the parallel quadrupole configuration. Further, the electrical connections to the rods, as well as the mounting of other components on the sensor must also be made in an extremely precise and delicate fashion to ensure that the rods remain in the exact quadrupole configuration.
Unfortunately, the precision drilling of the ceramic base and the precision mounting of the rods during assembly make prior art quadrupole residual gas sensors extremely expensive to manufacture. Consequently, prior art quadrupole residual gas sensors are typically very expensive to buy, so expensive in fact, that when the sensors become dirty after continued operation, they are usually disassembled and cleaned rather than replaced with a clean sensor. However, after cleaning, re-assembling the sensor still involves precise and careful mounting and handling of the components of the quadrupole. Hence, while cleaning the sensor is less expensive the replacing the sensor, cleaning the sensor is still very expensive.
Further, the extremely precise tolerances needed to construct the sensor with the ceramic base requires larger sensor components. Specifically, since screws and/or nuts are used to secure and seat the rods within the holes drilled in the ceramic base, the rods must have a sufficient diameter to permit the attachment and tightening of these nuts and screws. For these reasons, the cylindrical rods used to construct prior art quadrupole assemblies typically are at least a 1/4" in diameter.
One consequence of using large diameter rods mounted in a ceramic base to construct a quadrupole residual gas sensor is that the rods must be spaced farther apart in order to obtain a channel between the rods where the electric field can be tuned for ions having a specific mass-to-charge ratio. However, if the rods are farther apart, the electric field produced by each rod must still be the same in order to cause ions with the wrong mass-to-charge ratio to leave the channel. Unfortunately, however, expensive equipment is required to produce such high voltages.
Due to the difficulties and costs associated with manufacturing the above-described prior art quadrupole sensor, existing sensors are generally limited to a single four-rod quadrupole. An array of quadrupoles can be used to obtain a highly sensitive residual gas sensor. While an array of quadrupoles has been previously been suggested in a paper entitled Das elektrische Massenfilter als Massenspektrometer und Isotopentrenner, Paul, et al., Zeitschrift fur Physik, Bd., Apr. 21, 1958, the practical difficulties and high cost described above with constructing a sensor with just one quadrupole effectively prevents construction of a cost effective sensor incorporating an array of quadrupoles. Specifically, the cost of precisely drilling holes in a ceramic base to accommodate an array of rods, and the cost of precisely positioning the rods, effectively prevent the manufacture of an affordable quadrupole array based sensor. Further, as described above, the rods comprising the array would still have to be large diameter rods, spaced relatively far apart. Consequently, the size of an array of quadrupoles manufactured using the known techniques would be sufficiently large to limit its use in most low pressure or vacuum chambers.
Currently, the selectivity of the single prior art quadrupole sensor described above can only be improved by both increasing the length of the rods to lengthen the distance the ions must travel to the collector, and by increasing the frequency of the AC component of the voltages applied to the rods to create a more rapidly fluctuating electric field.
Typically, prior art quadrupole residual gas sensors have rods about 4 to 6 inches long. To maximize the sensitivity of the sensor, however, the length the ions must travel in the channel to the collector must be less than the mean free path of the ions. The mean free path of an ion is the mean distance the ion will travel in a straight line through its environment prior to colliding with another molecular particle. The channel length must, preferably, be less than the mean free path of the particle to thereby minimize the likelihood of an ion, with the tuned mass-to-charge ratio, colliding with another particle and being deflected out of the channel or neutralized. Tuned ions which are deflected in this manner will not impact upon the collector, resulting in a lower current being detected at the collector. The mean free path of a particle, such as an ion, can be calculated by a well known formula in which the mean free path is inversely proportional to the pressure of the environment that the particle is in. Hence, prior art quadrupole residual gas sensors must operate at extremely low pressures, e.g., 5.times.10.sup.-5 Torr, to be able to obtain a mean free path greater than the length of the channel between the ion source and the collector.
In many applications where there is a need to determine what gases exist in a chamber, the pressure in the chamber is substantially higher than the pressures necessary to operate the prior art sensor. For example, in the film deposition techniques used in the manufacture of semiconductor devices, the films are often deposited in chambers where the pressure may even be two orders of magnitude greater than the pressure needed to operate the above-described prior art sensors.
Consequently, the user is then reduced to sampling the contents of the low pressure chamber into a separate chamber, and then lowering the pressure in the separate chamber to obtain the pressure needed for the sensor to operate. As can be appreciated, the additional hardware necessary to implement such sampling is very expensive, and sampling is inherently inaccurate. Further, in these applications, the quadrupole residual gas sensor is not embedded in the low pressure chamber where the gas is being sensed, it is mounted in an extraneous chamber.
Consequently, there is a need in the prior art for an inexpensive residual gas sensor which uses an array of quadrupoles to increase sensitivity. Further, there is an additional need in the prior art for a sensor capable of operating at higher pressures to eliminate the costs and inaccuracies associated with sampling the contents of a low pressure chamber and to permit the sensor to be directly embedded in the chamber. Finally, there is a need in the prior art for both an inexpensive method of manufacturing these improved sensors, and an apparatus to facilitate such manufacturing.

Residual gas sensor utilizing a miniature quadrupole array


A porous coating for a medical implant, wherein the porous coating comprises a porous, shape memory material.

Today hip implant stems are typically a composite structure consisting of either a cobalt-chrome alloy or titanium alloy substrate that carries the patient's weight, with a textured surface coating composed largely of peaks and valleys to aid in immediate fixation and ultimately promote and facilitate long term osseointegration. See FIG. 1.
Today, the majority of implant coatings are textured, which are applied by hot plasma spray, vapor deposition (chemical and/or physical), or by sintering fiber mesh or beads. See FIG. 2.
These coatings processes leave a largely two-dimensional structure for the bone to grow around. There is no means for the bone to tunnel further into the coating so as to establish significant three-dimensional osseointegration. This may stifle or compromise long-term osseointegration. Additionally, the structures created using these technologies do not mimic the structure of trabecular bone which is three-dimensional, with interconnecting networks of pores with capillarity properties. See FIG. 3.
Recently, there have been advances in the creation of porous coatings that more accurately resemble trabecular bone. These porous surface coatings have interconnecting networks of pores which are similar to those of trabecular bone, and may serve to promote bone ingrowth deeper into the porous coating and provide better long-term implant fixation. There are several techniques known in the art for creating these porous coatings. One method is to coat a structure similar to trabecular bone, i.e., a polyurethane foam, with powdered titanium through low temperature arc vapor deposition (LTAVD) or chemical vapor deposition or sputtering, and then to sinter the resulting structure onto the substrate (hip implant). See FIG. 4.
Other methods include chemical vapor deposition of commercially pure tantalum onto porous carbon scaffold and then sintering the resulting structure onto the substrate (hip implant). See FIGS. 5 and 6.

Porous coating for orthopedic implant utilizing porous, shape memory materials


A secondary battery is disclosed. In one embodiment, the secondary battery includes i) a first electrode plate having two opposing surfaces, wherein the first electrode plate comprises a first electrode collector and a first electrode coating portion disposed on at least one of the two surfaces of the first electrode collector and ii) a second electrode plate having two opposing surfaces, wherein the second electrode plate comprises a second electrode collector and a second electrode coating portion disposed on at least one of the two surfaces of the second electrode collector. The secondary battery may further include a separator disposed between the first and second electrode plates and electrically insulating the first and second electrode plates from each other. The first electrode plate may further include a first electrode tab that extends from a first side surface of the first electrode collector, wherein the first side surface connects the two opposing surfaces of the first electrode collector, and wherein the first electrode coating portion extends to an extension region of the first electrode tab. The second electrode plate may further include a second electrode tab that extends from a second side surface of the second electrode collector, where in the second side surface connects the two opposing surfaces of the second electrode collector, and wherein the second electrode coating portion extends to an extension region of the second electrode tab.

1. Field
Embodiments of the invention relate to a secondary battery.
2. Description of the Related Technology
As electronic communication and computer technologies have advanced, portable electronic appliances have emerged for many practical applications as a source for power.
In general, a secondary battery includes an electrode assembly that is configured by a positive electrode plate, a negative electrode plate, and a separator disposed between the electrode plates.


A crime prevention monitor system which, when detecting an intruder entering into a monitor region, automatically judges quickly and reliably whether or not the intruder is an illegally intruding person on the side of its concentrator center and if so, then issues a highly reliable report to such a restraint organization as a police station. In the system, an image database having image data of authorized persons for the respective monitor regions previously registered therein is provided in the concentrator center so that, when the intruder is present in the monitor region, the image data of the intruder is sampled through a monitor camera and collated with the image data of the authorized persons of the monitor region in question, whereby, when the intruder does not correspond to any of the authorized persons of the associated monitor region, the system determines that the intruder is illegal and reports the presence of the intruder to the restraint organization.

1. Field of the Invention
The present invention relates to a crime prevention monitor system which monitors, on a remote control basis, the presence or absence of an illegal intruder entering into a monitor region to be monitored, such as an office, a shop, a school, a bank or a factory, on the basis of a picture signal received from a monitor camera installed in the monitor region for photographing the intruder.
2. Description of the Related Art
There has been so far well known such a sort of crime prevention system that a thermal radiation sensor or an infrared ray sensor is previously set in a monitor region to be watched so that when an intruder entering into the monitor region is detected by the sensor, the presence of the intruder is automatically reported to a concentrator installed in a security company and the like through a public line or a private line. With such a system, a guard of the security company rushes to the monitor region in question on the basis of the automatic report to the concentrator and when recognizing the abnormality on the spot, he or she quickly informs such a predetermined organization as a police station or a fire station of the abnormality.
The aforementioned crime prevention sensor and concentrator are usually interconnected by means of a transmitter which has a function of automatically calling the public or private line and by means of a receiver which enables communication of the transmission line in response to the calling of the transmitter through the line and sends a report signal received thereafter to the concentrator. When the crime prevention sensor detects the intruder entering into the monitor region, the following procedure is carried out and an automatic report to the concentrator is realized.
(1) The transmitter is started on the basis of an intruder detection signal received from the crime prevention sensor.
(2) The started transmitter automatically calls the receiver installed in the security company or the like.
(3) This results in the transmission line connected between the transmitter and the receiver being placed in its communication enable state.
(4) A predetermined report signal having identification data, etc. of the monitor region included therein is transmitted from the transmitter to the receiver.
(5) The transmitted report signal is demodulated at the receiver in a predetermined manner and then applied to the concentrator.
In this way, the prior art system can detect the presence or absence of the intruder entering into the monitor region accurately to a certain extent so long as the crime prevention sensor is high in detection accuracy. However, since the presence or absence of the intruder is judged only by the crime prevention sensor, when the intruder is one of authorized persons for the monitor region or when a mouse, a dog, a cat or a bird is detected as an intruder or when the aforementioned transmitter, receiver, etc. including the sensor are erroneously operated, for example, the system issues an erroneous report signal with a very low reliability. As a result, even when the above report is issued through a so-called terminal apparatus including the crime prevention sensor and transmitter disposed in the monitor region, the guard cannot determine that the report is actually correct until he rushes to the on-site monitor region and actually confirms the situation.
Further, with such a system, even when the above report is correct, the guard must confirm the on-spot situation, which inevitably requires a time loss until confirmation of the situation.
There has been recently proposed a crime prevention monitor system which can cope with such a situation as to require emergent confirmation with an improved reliability, and in which a monitor camera such as an industrial television (ITV) camera, is also installed in a monitor region to be guarded so that a picture signal from the monitor camera and the aforementioned report signal are transmitted from a terminal apparatus to a concentrator, whereby a watchman on at the concentrator can monitor the received picture image on a suitable display unit and can confirm the on-spot situation substantially on a real time basis. This crime prevention monitor system, however, has been disadvantageous in that it is hard for the watchman to judge whether or not the intruder into the monitor region is one of authorized persons therefor in actual situations because he usually cannot know substantially all information of the monitor region, which means that such a picture image is not effectively utilized.
As the number of terminal apparatuses increases not only the intruder detection and report accuracy of the crime prevention monitor system; but also its reliability; becomes very vital.


A method and apparatus for providing an early warning of thermal decay in magnetic storage media are provided. In accordance with an embodiment of the present invention, a test pattern that is particularly susceptible to thermal decay is written to a disk. The test pattern is then read, and the amplitude of the signal produced by the test pattern is stored. When testing for thermal decay is desired, the test pattern is again read, and the amplitude of the signal produced in the channel is compared to the stored amplitude. If the later amplitude is less than the stored amplitude by at least a predetermined amount, a thermal decay warning signal is generated. In accordance with another embodiment of the present invention, a test pattern is written to a portion of a disk that has been identified as being particularly susceptible to thermal decay. The amplitude produced by the test pattern is then stored so that it can later be compared to an observed amplitude when testing for thermal decay. The present invention allows remedial measures to ensure the integrity of data to be taken before data loss due to thermal decay can occur.

Computer disk drives store digital information on magnetic disks. The magnetic disks are generally coated with a magnetic material capable of changing the direction of its magnetic orientation in response to an applied magnetic field. Information is stored on the magnetic disks as a series of magnetic transitions. Typically, the information is stored on each disk in concentric tracks that are divided into servo sectors and data sectors. Information is written to or read from a disk by a transducer head mounted on an actuator arm that is capable of moving the transducer head radially over the disk. The movement of the actuator arm allows the transducer head to access different tracks. The disks are rotated by a spindle motor at a high speed, allowing the transducer head to access different sectors within each track on the disk. The transducer head may include integrated read and write heads.
In response to the increasing need to store large amounts of digital data in connection with computer systems, magnetic storage devices have utilized increased data storage densities. In order to support high data densities, the magnetic material of the magnetic disks must be provided in a very thin layer. In addition, high data densities require magnetic material with a small grain size. A thin layer and a small grain size reduce noise, and allow magnetic transitions to be more closely spaced together. However, the energy required to switch the magnetization of the material is decreased when the magnetic material has a small grain size and is provided in a thin layer. Accordingly, as the grain size and the layer thickness of the magnetic material has decreased, the material has become more susceptible to data loss due to thermal decay.
Thermal decay is related to the ratio of the energy barrier that must be crossed in order to switch the magnetization of the magnetic material of a magnetic disk to the thermal energy of the surrounding environment. In general, as the energy in the environment becomes more nearly equal to this energy barrier, thermal decay is more likely to occur. A magnetic disk having only a thin layer of magnetic material is particularly susceptible to thermal decay because the energy required to switch the magnetization of a portion of that disk is low. In addition, when data is stored at high densities, the area of the disk used to store a bit of information as a particular magnetic polarity (i.e. a bit cell) is small. Therefore, the energy required to switch the magnetization of a bit cell is reduced with increased areal densities. Furthermore, as grain sizes have been reduced, the anisotropic energy associated with each grain has also been reduced. As the anisotropic energy of each grain becomes nearer to the ambient thermal energy in a disk drive, information stored on the magnetic disk is more likely to be lost due to thermal decay.
As will be understood by those skilled in the art, the anisotropic energy of a grain is the fixed amount of energy required to maintain a stored direction of magnetization in the magnetic material, and is equal to the anisotropic energy density, Ku, times the volume of the grain, V. A thermal instability ratio is defined as the anisotropic energy divided by the thermal energy, kT, and is given by the formula KuV/kT, which should be greater than 50 in a conventional disk drive for adequate thermal stability. Ultimately, if a certain number of grains change their direction of magnetization due to thermal effects, the amplitude of a signal produced in the transducer head when the affected area is read will be decreased. Once the stored information decays beyond a threshold level, it will be impossible to properly read data written to the disk with the read head. In particular, the loss in the amplitude of a signal produced in the transducer head will cause data to be lost.
In order to address the effects of thermal decay, various measures have been taken. For example, error correction code may be used to restore data lost through processes such as thermal decay. However, the ability of error correction code to restore lost data is limited. In addition, the use of error correction code results in decreased user data density.
Attempts have also been made to produce magnetic disks having grains with large anisotropic energies. However, increasing the anisotropic energy of the grains generally requires larger grain sizes. As mentioned above, a larger grain size increases the noise of a signal produced by data stored on the magnetic disk. In particular, the transition noise is increased. Increased noise reduces the signal to noise ratio, and may adversely affect the bit error rate of the disk drive. In addition, if the anisotropic energy is increased by increasing the anisotropic constant (Ku), the coercivity (Hc) is also increased, and it becomes more difficult to write transitions to the magnetic disk.
Disk drive manufacturers have also limited the effects of thermal decay by requiring the magnetic material on a magnetic disk to be at least a certain minimum thickness, thereby increasing the volume of grains within a bit cell. However, as with increased grain sizes, increasing the thickness of the magnetic material increases noise when data is read from the magnetic disk.
For the above-stated reasons, it would be desirable to provide a method and an apparatus that allowed for increased data storage densities, without losing data due to thermal decay. In particular, it would be desirable to provide a method and an apparatus capable of providing an early warning of thermal decay. In addition, it would be advantageous to provide such a method and apparatus that are reliable in operation and that are inexpensive to implement.

Method and apparatus for providing an early warning of thermal decay in magnetic storage devices


The present invention relates to a diterpene compound derived from Aleurites fordii, and a pharmaceutical composition for treating or preventing viral infectious diseases, a health functional food for preventing or ameliorating viral infectious diseases and a composition for enhancing the production of interferon-gamma, which comprise the diterpene compound. Furthermore, the present invention relates to a method for preventing or treating viral infectious diseases including administering the composition to a subject having a viral infectious disease occurrence or a risk thereof with a therapeutically effective dose.

The production of interferon-γ(IFN-γ) in immunocytes is an important step in early-stage self-defense and tumor control against virus and bacterial infection (Biron, C. A. et al., Annu. Rev. Immunol. 1999, 17, 189-220). IFN-γ is produced in natural killer (NK) and natural killer T (NKT) cells that are generally used as effector cells in regulating immune reactions (Schoenborn, J. R. et al., Adv. Immunol. 2007, 96, 41-101). IFN-γ expression is particularly related to a pro-inflammatory state. The biological role of cytokain IFN-γ in a defense system is well known, and the role is related to both virus replication and direct suppression of immunostimulation (Gessani, S. et al., Cytokine & Growth F. R. 1998, 9, 117-123; Goodbourn, S. et al., J. Gen. Virol. 2000, 81, 2341-2364).
Pharmaceutical markets have grown globally due to an increase in incomes, aging population, increased demand for chronic disease-related medicines, life expectancy increase and the like, and as a result, research and development on biopharmaceuticals have increased in pharmaceutical industries at home and abroad. Among other things, there has been increased demand for antiviral therapeutic agent-related research that is the base of the development of AIDS therapeutic agents, and liver disease and influenza disease therapeutic agents, which are problems needed be solved for all mankind, for the development of therapeutic agents utilizing the results of the research, and for the development of medical technologies and technologies for improving quality of life.
A virus is a small infectious agent (average of 0.1 um or less) that is smaller than bacteria and thereby cannot be filtered even with a bacterial filter (0.22 um), and is an organism that has only nucleic acid (DNA or RNA) and a small number of proteins as substances needed for survival, and thereby are dependent upon hosts. As therapeutic agents for diseases caused by viruses, drugs that weaken or kill the action of viruses infested into the body are referred to as antiviral therapeutic agents.
Immunotherapy a vaccines is currently a mainstream viral infectious disease treatment. Specifically, examples of therapeutic agent for the infectious disease caused by chlamydia (giant virus) such as trachoma and fourth venereal disease (venereal disease) comprise tetracycline and chloramphenicol, examples of a preventive agent for influenza A-type virus include amantadine, an idoxuridine (IDU) eye bath drop was developed as a preventive agent for herpes keratitis, and vidarabine/acyclovir have received attention as a simple herpes encephalitis (encephalitis) or an immunosuppressant. Particularly, interferon is a most promising drug for viral infectious diseases, and usefulness thereof is currently being examined.
Lately, the preference for natural substances in treating or preventing health issues has grown globally. This trend is affecting pharmaceutical companies, in that they are producing new antimicrobial agents extracted from plants. Accordingly, research on exploring new anti-viral materials from thousands of plant types has been constantly carried out globally, and various phytochemicals having antiviral activities, such as flavonoid, terpenoid, lignan, sulfide, polyphenols, coumarin, saponin, alkaloid, polyyne, thiophene, proteins and peptides have been identified. Several volatile essential oils of generally used edible herbs, spices and herb teas also have antiviral activities. However, with the exception of a few compound groups described above, most research on the active substances of medicinal plants having antiviral activities is in its beginning stages.
Aleurites fordii is a deciduous tree of Dicotyledone Geraniales Euphorbiaceae, its scientific name is Aleurites fordii, and it is often referred to as a Tung oil tree. China is the country of origin, and its fruits, leaves and roots have been used in traditional oriental medicines to treat sore throat, respiratory disease and constipation (Pencreach G. et al., Anal. Biochem., 2002, 303, 17-24; Ito Y. et al., Cancer Lett., 1983, 18, 87-95).
Numerous compounds such as diterpenoid ester, sterol, tannin, oil and coumarin have been obtained through the chemical component analysis of Aleurites fordii (Fozdar B. I. et al., Phytochemistry, 1989, 9, 2459-2461; Lee Y. C. et al., J. Am. Pharmaceut. Assoc., 1959, 3, 162-165; Xie Y. F. et al., Zhongguo Tianran Yaowu, 2010, 8, 264-266). Among these, several biological activities such as piscicidal effects and Epstein-Barr virus activation have been reported for 12-O-hexadecanoyl-16-hydroxyphorbol-13-acetate (HHPA), a phorbol ester-based compound isolated from the leaf of Aleurites fordii (Hirota M. et al., Agri. Bio. Chem., 1979, 43, 2523-2529). However, the application for the treatment of viral infectious diseases has not been reported.

Phorbol type diterpene compound, pharmaceutical composition for treatment or prevention of viral infectious diseases including same

KOREA RESEARCH INSTITUTE OF BIOSCIENCE AND BIOTECHNOLOGY


A system and a method of manufacture of an integrated circuit system includes: a supply grid connected to an active component of an integrated circuit die; a high voltage capacitor connected to the supply grid; a low voltage decoupling capacitor connected to the supply grid; a pass gate gating the low voltage decoupling capacitor; and a pass gate control for controlling the pass gate to cause the high voltage capacitor and the low voltage decoupling capacitor to stabilize voltage of the supply grid during activity of the active component.

An integrated circuit (IC) system, which includes structured application specific integrated circuits (ASICs) and field programmable gate arrays (FPGAs), are used to implement large systems that may include millions of gates and megabits of embedded memory. Switching activities of components in the integrated circuit system put stress on power distribution networks (PDNs) supporting it. The changing states of logic and memory elements require the integrated circuit power distribution networks to supply more power than if the logic and memory elements were operating in a constant state. When a large number of logic and memory elements change states simultaneously, a large demand is placed on the power distribution networks (PDNs). Excessive voltage swings by the integrated circuit system can lead to faulty operation thereof.
To avoid unacceptable voltage deviations, the power distribution networks (PDNs) should be properly decoupled over switching frequencies of the integrated circuit system. Decoupling capacitors typically operate to decouple the PDNs over a range of switching frequencies. These decoupling capacitors store electric charges. When extra current is required from the PDNs, the decoupling capacitors can be discharged to meet the demands to stabilize the PDNs.
When the integrated circuit system supports multiple-voltage power distribution networks (PDNs), the decoupling capacitors need to meet requirements of different voltages of the PDNs.
Thus, a need still remains for an integrated circuit system having dynamic decoupling. In view of growing demands for supporting multiple signaling schemes, it is increasingly critical that answers be found to these problems. In view of the ever-increasing commercial competitive pressures, along with growing consumer expectations and the diminishing opportunities for meaningful product differentiation in the marketplace, it is critical that answers be found for these problems. Additionally, the need to reduce costs, improve efficiencies and performance, and meet competitive pressures adds an even greater urgency to the critical necessity for finding answers to these problems.
Solutions to these problems have been long sought but prior developments have not taught or suggested any solutions and, thus, solutions to these problems have long eluded those skilled in the art.

Integrated circuit system with dynamic decoupling and method of manufacture thereof


An apparatus including a first circuit and a second circuit. The first circuit may be configured to generate one or more first control signals in response to a reference impedance. The second circuit may be configured to operate in (i) a first mode in response to a first state of a second control signal and (ii) a second mode in response to a second state of the second control signal. When the second circuit is in the first mode, an output impedance of the second circuit may be adjusted in response to the one or more first control signals and the one or more first control signals may be presented at a first input/output of the second circuit. When the second circuit is in the second mode, the output impedance of the second circuit may be adjusted in response to one or more third control signals received at a second input/output of the second circuit.

The present invention relates to a method and/or architecture for implementing a programmable impedance generally and, more particularly, to a method and/or architecture for implementing a common programmable impedance pin for monolithic devices that may be used by at least two dies that each have separate programmable impedance circuitry.
Conventional ZQ-technology provides programmable impedance for single dies. Conventional single-die ZQ-circuitry does not allow for easy expansion by multiple die techniques, such as die stacking. Connecting the ZQ pad of all the dies in a package to a single pin drives current into all the pins. The current causes deviation from the resistance value on a single die, which would typically be in the range of 5 times the required impedance. Moreover, the circuitry on each of the dies responds at different times causing the effective output impedance to change erroneously.
Referring to FIG. 1, a typical single-die ZQ-technology programmable impedance circuit 10 is shown. The circuit 10 illustrates a programmable impedance architecture for QDR(trademark) SRAMs (QDR(trademark) is a trademark of Cypress Semiconductor, Inc., San Jose, Calif.). The circuit 10 includes a circuit 12 and a circuit 14. The circuit 12 has an input 16 that receives the signal ZQPAD. The circuit 12 also has an output 18 that presents the signal ZQCLK, an output 20 that presents the signal ZQLOAD and an output 22 that presents the signal ZQDATA. The circuit 14 has an input 24 that receives the signal ZQCLK, an input 26 that receives the signal ZQLOAD and an input 28 that receives the signal ZQDATA. The circuit 14 also has an output 30 that presents the signal O/P_PAD. The circuit 10 provides programmable impedance for a single die.
A designer typically chooses a,resistive value to program the impedance of a die by selecting a resistor that is five times the desired impedance value. The resistor is connected between ground and the pad ZQPAD. The ZQ circuitry 12 sends out a current and measures the resulting voltage on the pad ZQPAD. Based on the result, the ZQ-circuit 12 sends three signals (ZQCLK, ZQLOAD, and ZQDATA) to, the programmable output drivers 14. Such a configuration may allow the designer to match the output impedance of the device to the transmission line impedance on a printed circuit board, resulting in improved signal integrity. The drivers 14 use the data in the ZQ-signals to set the impedance of the signal O/P PAD.
It is generally desirable to implement ZQ-technology to implement a common programmable impedance pin for multiple-die implementations within the same package.
The present invention concerns an apparatus comprising a first circuit and a second circuit. The first circuit may be configured to generate one or more first control signals in response to a reference impedance. The second circuit may be configured to operate in (i) a first mode in response to a first state of a second control signal and (ii) a second mode in response to a second state of the second control signal. When the second circuit is in the first mode, an output impedance of the second circuit may be adjusted in response to the one or more first control signals and the one or more first control signals may be presented at a first input/output of the second circuit. When the second circuit is in the second mode, the output impedance of the second circuit may be adjusted in response to one or more third control signals received at a second input/output of the second circuit.
The objects, features and advantages of the present invention include providing a method and/or architecture for implementing a common programmable impedance pin for monolithic devices that may be used by at least two dies that each have separate programmable impedance circuitry that may (i) allow many device dies to be stacked together in the same package, (ii) keep existing pin configurations constant, (iii) allow programmable output impedance for stacked dies, and/or (iv) allow ease of expansion.

Master/slave method for a ZQ-circuitry in multiple die devices


A method for EFM demodulation is provided which includes a fuzzy logic-based ROM look-up conversion table capable of correcting data errors caused by invalid EFM bit patterns. The ROM look-up table contains the conversion data of valid EFM 14-channel bit patterns to 8-bit digital values. In addition to the valid pattern conversion, the ROM look-up table also includes fuzzy logic-based conversion of all invalid EFM 14-channel bit patterns to 8-bit digital values. The conversion of invalid EFM 14-channel bit patterns to 8-bit digital values allows error correction to begin during EFM demodulation using the inventive method. The invention improves the depth of the overall error correction system by correcting many of the data errors caused by invalid 14-channel bit patterns and most of the simple xe2x80x9coff by one clock periodxe2x80x9d invalid patterns.

1. Field of the Invention
The present invention relates generally to a circuit and method for EFM demodulation, and more specifically, to a circuit and method capable of correcting data errors caused by invalid EFM bit patterns during demodulation by using alconversion table, based on fuzzy logic.
2. Prior Art
Data is stored on a compact disc as a single spiral of pits and lands. The data is encoded as eight-to-fourteen modulation or EFM. EFM is an encoding technique where 8-bit digital values are converted into 14-channel bit symbols. The basic block diagram of all compact disc players includes an EFM demodulation stage. The EFM demodulation stage can be implemented using a ROM look-up table or a logic array.
The standard EFM conversion table defines the conversion of 8 bit digital to 14-channel bit symbols. The assignment of 8-bit digital to 14-channel bit symbols called out by the standard EFM conversion table was done arbitrarily and the 14-channel bit symbols do not follow a specific sequential binary progression. Bit patterns in the standard EFM conversion table were chosen carefully to minimize the number of transitions required to represent the original 8-bit digital data making the compact disc easier to manufacture and to establish a minimum and maximum length of pits and lands. The number of possible patterns for a 14-bit binary number is 16,384 and the number of patterns used to represent EFM is 258 (256 for data and 2 patterns for sub-code synchronization purposes) which leave 16,126 invalid patterns unused and undefined by the standard EFM conversion table.
The compact disc player uses a laser head assembly to read the reflective contrast of pit versus land and convert that contrast into a high frequency wave that is sliced at the zero crossing point into a digital series of ones and zeros. The format of the compact disc defines the data to be grouped into 588-channel bit frames. Each 588-channel bit frame includes a 24-channel bit synchronization pattern; one 14-channel bit sub-code symbol, twenty-four 14-channel bit symbols of data and eight 14-channel bit symbols of error correction code. Three merging bits separate the synchronization pattern and each 14-channel bit symbol. The merging bits are used to maintain the minimum and the maximum pit and land lengths and to minimize the DC content of the signal over time.
The pits on a compact disc are among the smallest structures ever manufactured. A compact disc may have as many as 3 billion pits. Pits of nine separate lengths are used on the compact disc. The pits range in size from the shortest that is 0.833 micrometers to the longest that is 3.05 micrometers in length. All of the pits are approximately 0.5 micrometers wide and approximately 0.11 micrometers deep. It may be easier to visualize just how small the pits on the compact disc are if you consider that a human hair is approximately 75 micrometers in diameter. Precise manufacturing control of the shape, length, width and depth of the pits is required to make a disc playable. Variations in the manufacturing process of compact discs can cause problems such as jitter or variation of pit and land lengths, which may cause data errors during playback. Data errors are common place and error correction circuits are required and can be found in all compact disc players. Traditional error correction on the compact disc player occurs after EFM demodulation (fourteen bit symbols back to 8-bit digital values). Existing compact disc systems do not prevent invalid EFM 14-channel bit patterns from entering the system and creating data errors during translation into 8-bit digital values and rely solely on an elaborate multiple stage error correction scheme for providing error-free data.
Error correction in a compact disc system:carries a format burden of 8 symbols of error correction code for every 24 symbols of user data. This format burden affects both data transfer rate and overall storage capacity of the compact disc. The error correction system is precise and effective, but at the same time is limited in the number of corrections it can make per frame of data before it fails and an entire frame of data is lost. An improvement to the system, which reduces errors, will also reduce the chance that the error correction circuitry will reach its limit and fail. The ideal improvement of the compact disc error correction system would be one that increases the error correction capability without increasing the burden or creating incompatibility.
Fuzzy logic is a form of logic where absolute or one-to-one correspondence is not required to determine the correct or most likely choice. The demodulation of EFM offers an ideal opportunity for the application of fuzzy logic. The patterns selected for EFM tend to be as different as possible from each other. The fact that EFM uses only 258 out of 16,384 patterns leaves many invalid patterns, which are very similar to valid EFM patterns.
The integrity of data in digital systems is of crucial importance. A single uncorrected data error in a software program can cause an entire system to fail. The manufacturers of compact discs and compact disc players go to great lengths to create a system which can deliver error-free data under less than ideal conditions. The consumer""s demands for less expensive and faster methods to transfer data from the compact disc continues to drive the industry. Industry""s response to this demand has tested the compact disc specification based on a 1xc3x97 data rate. The original compact disc specification detailed how to build a disc and player for 1xc3x97 data rate, where present day compact disc drives commonly used in computer systems are now approaching data rates of 50xc3x97 and beyond.
Briefly, in accordance with the invention, a method for EFM demodulation is provided which includes a fuzzy logic-based ROM look-up conversion table capable of correcting data errors caused by invalid EFM bit patterns. The ROM look-up table contains the conversion data of valid EFM 14-channel bit patterns to 8-bit digital values. In addition to the valid pattern conversion, the ROM look-up table also includes fuzzy logic-based conversion of all invalid EFM 14-channel bit patterns to 8-bit digital values. The conversion of invalid EFM 14-channel bit patterns to 8-bit digital values allows error correction to begin during EFM demodulation using the inventive method.
Considering that there are 16,384 possible 14-channel bit patterns and EFM uses only 258 of those patterns, it is not surprising that a high percentage of data errors that occur in EFM tend to fall outside of the 258 valid 14-channel bit patterns. All data errors caused by invalid EFM 14-channel bit patterns have a chance of being corrected during conversion back to 8-bit digital values by the invention. The invention is not limited to how many symbols it can correct per frame as the traditional error correction circuitry. The invention improves the depth of the overall error correction system by correcting many of the data errors caused by invalid 14-channel bit patterns and most of the simple xe2x80x9coff by one clock periodxe2x80x9d invalid patterns. The inventive method relies on traditional error correction circuits for the errors that do not show up as invalid patterns or those that it is unable to resolve. If the inventive method is unable to correct an error caused by an invalid EFM 14-channel bit pattern, the attempt to correct the error is transparent to the preceding error detection and correction circuits. The error detecting and correcting circuits detect and correct the error just as if the invalid EFM 14-channel bit pattern has been demodulated by a traditional EFM demodulation circuit.
The inventive method is not limited to compact disc applications, but can be used in other systems such as digital versatile disc (DVD), digital audio tape (DAT) and other systems which use EFM or similar block encoding.
An alternate method and circuit to correct errors caused by invalid EFM 14-channel bit patterns is implemented by adding digital logic gates to the shift register stage of an EFM demodulator. A percentage of errors caused by invalid 14-channel bit patterns can be corrected by converting invalid channel bit patterns detected as 1T and 2T channel bit lengths to valid 3T channel bit lengths using digital logic gates in conjunction with the shift register stage of the EFM demodulator.
The alternate method and circuit will convert some of the invalid 14-channel bit patterns to valid 14-channel bit patterns before the parallel output of the shift register is used as the address to a standard EFM conversion table. Therefore, some errors caused by invalid 14-channel bit patterns will be corrected.
The digital logic circuits convert invalid 1T and 2T channel bit lengths to valid 3T channel bit lengths while the channel bits are shifted through the shift register in the EFM demodulator circuit.
The alternate method and circuit is simpler to implement than the method and circuit of the preferred embodiment. However, the alternate method and circuit does not attempt to correct all possible invalid 14-channel bit patterns and does not base it""s conversion of invalid patterns on a fuzzy logic comparison to valid 14-channel bit patterns. Therefore, the error correction performance of the alternate approach is inferior to the fuzzy logic-based look-up table described in the preferred embodiment.
The logic gates detect the occurrence of 1T pattern xe2x80x9c0110xe2x80x9d within the 14-channel bit symbol and convert the 1T pattern to a 3T xe2x80x9c1001xe2x80x9d pattern. The 2T pattern of xe2x80x9c1010xe2x80x9d is also converted to a 3T xe2x80x9c1001xe2x80x9d pattern by the digital logic gates.
It is therefore a principal object of the present invention to provide a circuit and method for EFM demodulation and which is capable of correcting data errors caused by invalid EFM bit patterns using a fuzzy logic-based ROM look-up table.
It is also an object of the present invention to improve the overall error correction capability by working in conjunction with the existing compact disc player error correction circuits without adding burden or incompatibility to the compact disc format. By improving the error correction capability of the error correction system, the resulting compact disc player will be more robust and fault tolerant.
It is another object of the present invention to allow the correction of errors caused by invalid EFM bit patterns to begin prior to the existing error correction circuits of the compact disc player and not add further delay (in comparison to traditional EFM demodulation).
It is still another object of the present invention to provide a method of EFM demodulation, which method can begin correcting errors caused by invalid EFM bit patterns before traditional error correction circuits that can be easily added to integrated circuit designs which currently include a traditional EFM demodulation stage.


A liquid-crystal display apparatus includes a layer of liquid crystal. A matrix array is composed of scanning electrodes and signal electrodes. The scanning electrodes extend along a matrix row direction. The signal electrodes extend along a matrix column direction. Switching circuit elements are located at respective places where the scanning electrodes intersect with the signal electrodes. Pixel electrodes connected to the switching circuit elements are operative for controlling portions of the liquid-crystal layer respectively. A first device is operative for driving the scanning electrodes. A second device is operative for delaying a first video signal into a second video signal. A third device is operative for alternately selecting one out of the first video signal and the second video signal to generate a third video signal in response to the first video signal and the second video signal. A fourth device is operative for periodically inverting a polarity of the third video signal at a timing synchronous with alternately selecting by the third device to convert the third video signal into a fourth video signal. A fifth device is operative for feeding the fourth video signal to the signal electrodes.

Field of the Invention
This invention relates to a liquid-crystal display apparatus including a liquid-crystal display panel of the active matrix type.
Description of the Prior Art
Some liquid-crystal display apparatuses have a matrix array of 1-pixel-corresponding cells. These cells include different 1-pixel-corresponding areas of a liquid-crystal layer, respectively. Each of the cells further include a storage segment, and a switching transistor connected to the storage segment. The storage segment of each cell can be accessed via the related switching transistor. Scanning circuits control the switching transistors in the cells, and thereby sequentially write 1-pixel-corresponding segments of a video signal into the storage segments of the cells, respectively. In each cell, the storage segment continuously subjects the 1-pixel-corresponding area of the liquid-crystal layer to a signal voltage (an electric field) depending on the 1-pixel-corresponding segment of the video signal. Accordingly, light in the 1-pixel-corresponding area of the liquid-crystal layer is modulated with the 1-pixel-corresponding segment of the video signal.
Japanese published examined patent application 4-67192 discloses such a liquid-crystal display apparatus. In the display apparatus of Japanese application 4-67192, the polarity of an applied video signal is inverted in every field. Thus, the polarity of the video signal during each odd-numbered field is opposite to that during each even-numbered field. Accordingly, in the case where a field frequency is 60 Hz, a liquid-crystal layer is driven at a frequency of 30 Hz. In this case, the brightness of an indicated picture changes every field so that the indicated picture tends to flicker.


A first toroidal ray guide defines an axis of revolution and has a toroidal entrance pupil adapted to image light incident on the entrance pupil at an angle to the axis of revolution between 40 and 140 degrees, and it also has a first imaging surface opposite the entrance pupil. A second toroidal ray guide also defines the same axis of revolution and has a second imaging surface adjacent to the first imaging surface. Various additions and further qualities of the ray guides, which form optical channels, are disclosed. In a method light emanating from a source at between 40-140 degrees from an optical axis is received at an entrance pupil of a ray guide arrangement that is circularly symmetric about the optical axis. Then the received light is redirected through the ray guide arrangement to an exit pupil in an average direction substantially parallel to the optical axis.

How to collect all the light emitted from a certain source and further to shape the beam into a desirable form is a well known problem. An ideal solution for many applications would be to image the source by using the rays emitted to one hemisphere about the source. Here the term 'imaging' does not mean image forming with minimized aberrations but merely imaging with a sufficient quality for illumination.
One well-known approach is to use high-NA (numerical aperture) objectives, like aspherical pick-up lens systems or microscope objectives. These solutions are either large in respect to the collected etendue, or incapable to form good enough image from the object. These systems may also be complex and expensive. These teachings take a different approach. Instead, embodiments of this invention make it possible to form an illumination quality image of an object by using the rays emitted at large angles to the optical axis of the imaging system (e.g., side-emitted rays).
The light collection problem becomes more difficult if one needs to collect all the light emitted from a source which is inside a material whose refractive index n is larger than that of the surrounding material, typically air (n=1). Typically, large angle collection is possible only if the source is in air. If the source is encapsulated in higher refractive-index material, typical collection optics tends to be too large to be useful. Additionally, many typical optical collection solutions (such as collection lenses, TIR-collimators, tapered lightpipes, parabolic concentrators) only collect light and other components are needed to shape the beam to a desired form such as a uniform rectangle for example. That results in a larger optical system size and additional losses due to the increased number of discrete components or due to increased etendue of the beam. Embodiments of this invention address this problem in that the components described make it possible to form image of an object at large angles even when the object is inside a material with an index of refraction greater than the surrounding material.
In many applications it would be advantageous to have a very low-F-number objective, technically an ultra-high numerical aperture, which need not have perfect imagery but rather a high throughput. Embodiments of the invention address this issue in that the numerical aperture of the components described herein can be equal to the refractive index of the material by which the object to be imaged is surrounded.
There are other design considerations where an object or data needs to be imaged from angles far from the optical axis. For example, in some applications the optical axis is blocked or unavailable for direct imaging due to other uses, and there is also a need to illuminate the object with high throughput. As will be seen below, embodiments of the invention address that problem also.
In miniature LED projection engines, one difficult problem is how to couple the light from the LED chip through a rectangular microdisplay and the projection lens onto the screen. This needs to be done efficiently and in a small space and still provide uniform image quality. Those considerations are fully described and designed for in co-owned U.S. Pat. No. 7,059,728 by enclosing an LED source within an optical medium on one side and a reflecting substrate on the other. Light from the non-point LED source is distributed throughout the optical medium. Due to reflective and transmissive surfaces having micro-scale diffractive and/or refractive surface patterns, the distributed light is collected into a rectilinear output with relatively uniform intensity. But in addition to those technical considerations, the illumination component(s) need to be mass-manufacturable at a reasonable cost. These teachings further address that challenge in that embodiments detailed herein provide an illumination system and method for LED (or other light source) based projectors which is small, has high efficiency and good uniformity, and is further efficiently mass-producible and robust.
The closest known prior art is seen to be a total internal reflection TIR-collimator, such as that used in the Mitsubishi® PK-10 LED projector. A schematic drawing of that TIR collimator and an image of the same are shown respectively at FIGS. 1A-B. The outer diameter of this component is about 20 mm. One problem seen with such a TIR collimator is that it collects the light but it does not form an image of the source so a separate fly's eye lens is apparently necessary in order to render the output illumination uniform and rectangular instead of a circularly symmetric. That causes either (or both) loss of light or increase of system size by increasing the etendue of the beam.
Separately, the concentration of light from a diffuse light source is required for many applications. One good example is the concentration of solar radiation. In solar concentration some problems with prior art systems known to the inventor is that they are incapable of concentrating light with near the maximum concentration ratio, and they are physically large with respect to the power they deliver. Some renditions also require some optical surfaces to be in near proximity to the location where light is concentrated, which can cause severe problems when a maximum concentration ratio is used because that optical surface will be affected where the light has a very high intensity. Also, for prior art concentrators that are based on parabolic reflectors, the heating element is disposed above the parabolic mirrors, which is a difficult physical arrangement. Embodiments of this invention address these concerns in that the components described can be used to concentrate light with a concentration ratio close to the theoretical maximum, but without the above problems. Specifically, a solar concentrator according to the teachings below may exhibit an almost maximum possible concentration ratio, with no optical surfaces near the heating element, and with the heating element below the concentrator which enables the heating element to be in a fixed position so that only the concentrator needs to track the movement of the sun.
In other fields such as microscopy or the optical measurements field, certain applications require a bright spot of light. This also is an advantageous deployment of the embodiments detailed below.


A distance from the bottom of a mesa groove to an underlying pn junction exceeds the elongation of a depletion layer from the underlying pn junction that occurs when a voltage nearly equal to a target withstand voltage is applied, and a groove width of a section other than a corner of the mesa groove, that is, the groove width of a straight section, is nearly equal to the distance from the bottom of the mesa groove to the underlying pn junction.

To supply triacs and other high-withstand-voltage semiconductor elements with low prices, a method is adopted in which grooves are formed by so-called mesa etching to terminate pn junctions at the semiconductor surface, and glass is packed as a surface-stabilizing material into these mesa grooves.
For example, in a mesa-type triac having mesa grooves on both sides of the element, as shown in FIG. 11, base layers 2a and 2b made of p-type diffusion layers are formed on the front and back surfaces of an n-type substrate 1, emitter layers 3a and 3b made of n-type diffusion layers are formed in the base layers 2a and 2b, respectively, a mesa groove 4 is formed in such a way that it encircles the outside of this, and glass 5 is filled in the mesa groove.
In addition, there are also semiplanar-type triacs having a mesa groove 4 on only one surface of the element, as shown in FIG. 12.
When a voltage is applied in an OFF state to such triacs, the pn junction between the substrate and the upper or lower base becomes a reverse junction depending on the polarity of the applied voltage, a depletion layer forms its vicinity and the electric current is blocked. To attain a high withstand voltage, therefore, it is necessary to prepare a high-resistance substrate in which the breakdown voltage of the pn junction is equal to or greater than a target withstand voltage. As used herein, the term "high withstand voltage" refers to a withstand voltage of 1200 V or higher.
For example, when the object is to obtain a withstand voltage of 1500 V, then, theoretically, it is sufficient to use a substrate having a resistivity of 30 .omega.cm, as is evident in FIG. 13, but in practice a substrate having a resistivity of higher than 30 .omega. must be used because in addition to the substrate resistance, there are crystal defects or impurity contaminants in the substrate, unevenness or roughness in the junction surfaces or mesa groove surfaces, curvature of the mesa groove surfaces, and other factors that lower the withstand voltage.
Thus, the substrate resistance must be made fairly high and the withstand voltage of the reverse junction between the base and the substrate must be raised in order to obtain a semiconductor element having high withstand voltage.
However, an increase in the substrate resistance is accompanied by an increase in the elongation of the depletion layer near the pn junction that occurs when a voltage is applied, as shown in FIG. 14. This is the reason that when a high withstand voltage exceeding a certain limit is applied, the depletion layer projects upward or downward and reaches yet another base layer, or projects outward in the transverse direction, passes under the mesa groove, and reaches the isolation layer (diffusion layer for element separation), and a breakdown occurs due to a punch-through, as shown in FIG. 15. For this reason, there has been a disadvantage that a high withstand voltage above the aforementioned limit cannot be attained merely by raising the substrate resistance.