In a method for preparing a starch solution, particles containing starch are mixed with cold water and subjected to shear forces, such that any agglomerates formed are broken up, and each individual particle is wetted, whereupon the mixture is heated to at least about 60.degree. C. and maintained in the heated state until the viscosity maximum of the solution has passed. The wetting and the heating take place before a viscosity that is unacceptable from the point of view of handling has been reached.. A device for implementing the method, a starch solution prepared in accordance with the method, and the use of such a starch solution for making paper are also disclosed.

The present invention relates to a method and a device for preparing a starch solution; a solution prepared in accordance with this method; and the use of such a solution for making paper.
In papermaking, cationic starch is widely used as a retention agent and strengthening agent. In recent years, cationic starch has to a large extent been employed together with anionic, inorganic materials, such as bentonite and various silica-based sols, to improve the retention and/or drainage in papermaking, see, for instance, EP Patent 41,056 and PCT Applications WO 86/00100 and WO 89/12661.
It has recently become possible to prepare high-cationized starch, i.e. starch with a degree of substitution exceeding 0.07. For instance EP Patent Specifications 233,336 and 303,039 disclose how this can be done by dry cationization, the latter disclosing the use of sodium aluminate as catalyst.
Generally, when starch is dissolved in water, the viscosity increases at first, and then decreases to a lower level. Thus, a viscosity maximum has to be passed, and this can, when dissolving low-cationized starch, only be achieved by thermal treatment at a temperature exceeding about 80.degree. C. For conventional dissolution of low-cationized starch, the starch is mixed with cold water in a slurry tank and subsequently boiled.
In the above-mentioned patent specifications, the high-cationized starch is said to be soluble in cold water. In cold-water dissolution, however, it is difficult to pass the viscosity maximum in a reasonable time and obtain a solution substantially free of unswelled starch grains, which is desirable if the solution is to give satisfactory results when used for making paper. Thus, cold-water dissolution necessitates long residence times while requiring a not too high dry content, for which reason the equipment used has to be dimensioned for large volumes.
To use heat during the dissolution process, in accordance with the method commonly employed for low-cationized starch, results in a high increase of viscosity in the slurry tank, which makes further handling of the solution more difficult. This increase is especially pronounced if sodium aluminate has been used as activator in the preparation of the starch, which thus contains aluminum.
It has therefore been necessary to maintain an extremely low dry content so that considerable amounts of energy are needed for the subsequent heating. Also in this case, the dissolution device including the heater has to be dimensioned for relatively large volumes, which leads to high costs.
Thus, it is desirable to reduce energy and investment costs by dissolving high-cationized starch during thermal treatment at high dry contents, preferably exceeding about 2% by weight.


In TV receiving apparatus, a first IF amplifier chain comprises a first gain-controlled amplifier followed in cascade connection by a second gain-controlled amplifier, and a second IF amplifier chain comprises a third gain-controlled amplifier followed in cascade connection by a fourth gain-controlled amplifier. The second and fourth gain-controlled amplifiers are controlled similarly by an AGC signal, and the first and third gain-controlled amplifiers are controlled similarly by that AGC signal delayed in similar amounts. An RF amplifier is gain-controlled responsive to that AGC signal delayed even more, and a downconverter supplies first detector response to amplified RF, which first detector response is applied to the first and second IF amplifier chains by respective frequency-selective filters. The first IF amplifier response is downconverted to generate sound IF. The second IF amplifier response is detected to recover video signal. An AGC detector detects the peaks of the synchronizing pulses included in the video signal to develop the AGC signal.

The recent practice in regard to implementing the IF filtering and gain functions in television signal receiving apparatus is to use a lumped or "block" filter preceding a gain-block amplifier comprising plural stages arranged in direct-coupled cascade within the confines of a monolithic integrated circuit (IC). No interstage tuning is used. The amplified IF signal from the gain-block IC amplifier is further detected substantially within the confines of the monolithic integrated circuit, to emerge from the IC as baseband composite video signal and as sound IF at 4.5 MHz. The amplified IF signal is filtered from these signals to reduce the likelihood of regeneration causing the gain-block amplifier to oscillate.
The "block" filter is commonly a surface-acoustic-wave (SAW) filter used to provide the entire passband shape and adjacent channel attenuation required by a television receiver. Additional information on SAW filters and on block filtering and amplification may be found, for example, in Chapter 13 of the book TELEVISION ENGINEERING HANDBOOK; K. Blair Benson, Editor in Chief; McGraw-Hill Book Company, New York; 1986.
There are conflicting requirements on video IF amplification inasfar as best picture reception and best sound reception are concerned, which conflicting requirements are more difficult to resolve when a block filter preceding a gain-block amplifier is used to provide IF amplification. Good picture reception, with full resolution capability in the direction of horizontal sweep, requires that the IF signal as supplied to the video detector does not include response to in-channel sound carrier. Accordingly, in television signal receiving apparatus using discrete amplifying devices with interstage tuning, an in-channel sound trap commonly precedes the video detector. Good picture reception further requires that the IF signal as supplied to the video detector does not include response to adjacent-channel sound carrier, which response intrudes "sound beats" into the picture. In television signal receiving apparatus using discrete amplifying devices with interstage tuning, an adjacent-channel sound trap precedes the video detector and provided high (40 dB or so) rejection over the band in which the adjacent-channel sound signal as translated to IF appeared. To obtain such rejection and still maintain acceptably linear phase response for composite video, the video carrier as translated to an IF has to be located on the edge of the adjacent-channel sound trap rejection response, and is normally attenuated 6 dB or so. When a block filter preceding a gain-block amplifier is used to provide IF amplification, the traps for adjacent-channel and in-channel sound have to be provided within the block filter preceding the gain-block amplifier providing amplified IF for direct coupling to the video detector, which can be used for the generation of intercarrier sound.
Sound reception in a TV receiver using intercarrier sound exhibits better signal-to-noise ratio, however, when the sound and video carriers as translated to IF are not attenuated respective to mid-band prior to their being mixed together to generated 4.5 MHz sound IF signal. To achieve better sound reception while adhering to the design concept of block filtering, a further block filter and gain-block amplifier cascade is used for intercarrier sound in the invention, in addition to the block filter and gain-block amplifier cascade used to drive the video detector. The two gain-block amplifiers are preferably constructed in substantially the same way within the confines of the same monolithic IC, the inventor points out, such that their operating characteristics track each other. Preferably each of the gain block amplifiers has a balanced conversion stage cascaded thereafter within the IC, so the frequency of its output signal as supplied from the IC differs from the frequency of its input signal as supplied to the IC. This reduces the risk of the gain block amplifier regeneratively oscillating. To further reduce the risk of regenerative interaction between the two gain-block amplifiers, one gain-block amplifier can provide balanced output signals responsive to single-ended input signal, and the other gain-block amplifier can provide single-ended output signal responsive to single-ended input signals. The tracking of the gain-control characteristics of the two gain-block amplifiers is particularly important, since it allows an automatic gain control signal developed by detecting the tips of synchronizing pulses from the video detector cascaded after one of the two gain-block amplifiers to be applied in parallel to both the gain-block amplifiers for controlling their gains similarly.
In television signal receiving apparatus of the type having only a single conversion before video detection, the IF amplifier is typically required to handle input signals ranging from about 50 microvolts to about 100 millivolts RMS, which represents a dynamic range of about 66 dB. U.S. patent application Ser. No. 07/940,220 filed Sep. 8, 1992 by Jack Rudolph Harford and Heung Bae Lee, entitled VARIABLE GAIN AMPLIFIER, describes gain-block stages suitable for use in the invention herein described and claimed. As is the case in the present application, U.S. patent application Ser. No. 07/940,220 has been assigned to Samsung Electronics co., Ltd., pursuant to obligations of the inventor(s) to assign his (their) invention(s) at the time the inventions were made. In these gain-block stages a 66 dB range of gain control can be achieved using only two gain-controlled voltage amplifier stages, which facilitates the tracking of the gain-control characteristics of the two gain-block amplifiers.

Parallel untuned video if amplifiers supplied signals from TV 1st detector via respective input filters


A first antenna configuration contemplates a body housing and an antenna cap positioned at a top portion of the body housing. A helical winding is disposed within the antenna cap for radiating electromagnetic waves. A reflecting plate is installed within the antenna cap at a spaced-apart distance from the helical winding for reflecting the electromagnetic waves in a direction away from a user. Polyacetal material is disposed within the antenna cap for supporting the reflecting plate.

The present invention relates to an antenna for portable radio sets, and more particularly, to an antenna for portable radio sets in which a reflecting plate is provided for reflecting radiated waves.
In the prior art, a helical antenna and a rod antenna have been combined to form a unitary antenna structure for a portable radio set. With this construction, it is possible to separately operate the helical antenna when the rod antenna is retracted, or to separately operate the rod antenna when the rod antenna is extended.
One prior art reference having both a helical and rod antenna is disclosed in U.S. Pat. No. 4,868,576 entitled Extendable Antenna for Portable Cellular Telephones with Ground Radiator issued to Johnson. In Johnson '576, the rod antenna is positioned on a top portion of a housing and includes two detents which engage tangs of an antenna housing when retracted and extended. The tangs snap into the detents, thereby providing the operator with tactile feedback indicating whether the antenna is fully retracted or extended. The rod antenna slides into and out of the antenna housing, through a helical coil. The rod antenna also includes a protective top end cap, a top portion with the detent, a middle portion with a coil, a bottom portion with the detent and a bottom end cap. The rod antenna is comprised of a flexible plastic material, such as "Delryn" with the mid-portion coil comprised of silver-plated beryllium-copper wire having a diameter of 13 mils (13/1000th of an inch). Therefore, when the rod antenna is retracted, the unit operates as a helical antenna. When extended, the rod antenna is capacitively coupled to the helical antenna. As a result, the configuration is operated in accordance with the length of the rod antenna.
Consequently, the conventional antenna configuration described above distributes centralized radiating power (maximally, 0.6 W) to the helical antenna or the rod antenna. Therefore, a problem results in that harmful electromagnetic waves may be applied to a user's head.

Antenna for portable radio sets having reflecting plate


A mask frame assembly for depositing a deposition material on a deposition substrate comprises a mask frame including an opening and frames surrounding the opening, and a mask coupled on the mask frame. A deformation prevention unit is formed on at least one region of the mask. Since the deformation prevention unit is formed on a peripheral portion of a deposition pattern in the mask, deformation of the mask in a vertical direction may be reduced. Accordingly, defective attaching of the mask to the substrate may be reduced.

1. Field of the Invention
The present invention relates to a mask frame assembly for thin film deposition, and more particularly, to a mask frame assembly for thin film deposition which prevents a mask from deforming.
2. Description of the Related Art
In general, organic light emitting display devices (OLEDs) including a thin film transistor (TFT) may be used in display devices in mobile appliances such as digital cameras, video cameras, portable information terminals, smart phones, tablet computers, or ultra-thin laptop computers, and electronic devices such as ultra-thin televisions.
An OLED emits lights of different colors when holes and electrons injected into an anode and a cathode recombine in an organic emission layer. The OLED is a stack type display device in which the organic emission layer is inserted between the anode and the cathode.
However, according to the above-described structure, highly efficient light emission may not be performed, and thus, intermediate layers such as an electron injection layer, an electron transport layer, a hole transport layer, and a hole injection layer are selectively inserted between the electrodes and the organic emission layer.
The electrodes and the intermediate layers, including the organic emission layer of the OLED, may be formed via a photolithography method or a deposition method.

Mask frame assembly for thin film deposition

Samsung-ro, Giheung-Gu, Yongin-si, Gyeonggi-Do


In an internal combustion engine that includes a first secondary air supply unit having a first air pump and a first air switching valve and a second secondary air supply unit having a second air pump and a second air switching valve, a time difference is provided between the operation start timing of the first air pump and the operation start timing of the second air pump, and the open timing of the first air switching valve and the open timing of the second air switching valve are set so as to be simultaneous with each other.

1. Field of the Invention
The invention relates to a secondary air supply system and secondary air supply method for an internal combustion engine, which supply air into exhaust gas from the internal combustion engine.
2. Description of Related Art
A catalyst is arranged in an exhaust passage of an internal combustion engine, and toxic substances of exhaust gas are purified by the catalyst through oxidation-reduction reaction. In order to activate the catalyst so as to purify exhaust gas, the temperature of the catalyst needs to be higher than or equal to its activating temperature. Therefore, in order to quickly ensure exhaust gas purification performance after a start-up of an engine, the temperature of the catalyst needs to be early increased.
Then, in an art, there is suggested an internal combustion engine that includes a secondary air supply system as described in Japanese Patent Application Publication No. 2007-024034 (JP 2007-024034 A) to thereby early increase the temperature of the catalyst. The secondary air supply system is formed such that a secondary air supply passage in which an air pump that pressurizes air and discharges the pressurized air and an air switching valve that opens to permit or closes to prohibit introduction of air, discharged from the air pump, into exhaust gas are arranged is connected to the upstream side of a catalyst in an exhaust passage. In an internal combustion engine that includes such a secondary air supply system, secondary air is supplied into exhaust gas and the air-fuel ratio of burned air-fuel mixture is enriched to cause unburned fuel to be burned on the catalyst to thereby make it possible to early increase the temperature of the catalyst.
Note that the secondary air supply system described in JP 2007-024034 A is formed such that a secondary air supply passage in which an air pump and an air switching valve are provided is connected one by one to each of two exhaust pipes in which catalysts are respectively arranged. In such a secondary air supply system that includes two secondary air supply units, as the two air pumps simultaneously start operation, a voltage drop of a battery may become excessively large because of large inrush currents of the air pumps. Therefore, in this secondary air supply system, a time difference is provided between the timings at which the two air pumps start operation to thereby suppress a voltage drop of the battery.
Incidentally, in the thus configured secondary air supply system, at the time at which the pressure of supplying secondary air sufficiently increases after a lapse of a predetermined period of time from the start of operation of the air pumps, the air switching valves are opened. Therefore, when a time difference is provided between the operation start timings of the two air pumps, a time difference also occurs between the timings at which the two air switching valves are opened. When the air switching valve is opened, operation sound occurs because of a variation in pressure in the valve. Therefore, as a deviation occurs between the timings at which the two air switching valves open, the above described sound successively occurs twice, so the operation sound of each air switching valve becomes a tone that causes a passenger to experience a feeling of strangeness.

Secondary air supply system and secondary air supply method for internal combustion engine


A storage server maintains multiple file systems in a storage subsystem. A read-only, persistent, point-in-time image of all of the file systems is generated in one atomic operation.

Various forms of network-based storage systems are known today. These forms include network attached storage (NAS), storage area networks (SANs), and others. Network storage systems are commonly used for a variety of purposes, such as providing multiple users with access to shared data, backing up critical data (e.g., by data mirroring), etc.
A network-based storage system typically includes at least one storage server, which is a processing system configured to store and retrieve data on behalf of one or more client processing systems ("clients"). In the context of NAS, a storage server may be a file server, which is sometimes called a "filer". A filer operates on behalf of one or more clients to store and manage shared files. The files may be stored in a storage subsystem that includes one or more arrays of mass storage devices, such as magnetic or optical disks or tapes, by using RAID (Redundant Array of Inexpensive Disks). Hence, the mass storage devices in each array may be organized into one or more separate RAID groups.
In a SAN context, a storage server provides clients with block-level access to stored data, rather than file-level access. Some storage servers are capable of providing clients with both file-level access and block-level access, such as certain Filers made by Network Appliance, Inc. (NetApp®) of Sunnyvale, Calif.
In conventional file servers, data is stored in logical containers called volumes and aggregates. An "aggregate" is a logical container for a pool of storage, combining one or more physical mass storage devices (e.g., disks) or parts thereof into a single logical storage object, which contains or provides storage for one or more other logical data sets at a higher level of abstraction (e.g., volumes). A "volume" is a set of stored data associated with a collection of mass storage devices, such as disks, which obtains its storage from (i.e., is contained within) an aggregate, and which is managed as an independent administrative unit, such as a complete file system. A "file system" is an independently managed, self-contained, hierarchal set of data units (e.g., files, blocks or LUNs). Although a volume or file system (as those terms are used herein) may store data in the form of files, that is not necessarily the case. That is, a volume or file system may store data in the form of other units, such as blocks or LUNs.
In older file servers, there was a fixed, one-to-one relationship between a volume and its containing aggregate, i.e., each volume was exactly coextensive with one aggregate. Consequently, there was a fixed relationship between each volume and the disks that are associated with it. This fixed relationship meant that each volume had exclusive control over the disks that are associated with the volume. Only the volume associated with the disk could read and/or write to the disk. Unused space within the disks associated with the volume could not be used by another volume. Thus, even if a volume was only using a fraction of the space on its associated disks, the unused space was reserved for the exclusive use of the volume.
To overcome these limitations and other limitations of traditional volumes, a technology called flexible volumes was developed by NetApp® and is available in NetApp® Filers as a feature of the Data ONTAP® storage operating system. A flexible volume is analogous to a traditional volume, in that it is managed as a file system; but unlike a traditional volume, a flexible volume is treated separately from the underlying physical storage that contains the associated data. A "flexible volume" is, therefore, a set of stored data associated with one or more mass storage devices, such as disks, which obtains its storage from an aggregate, and which is managed as an independent administrative unit, such as a single file system, but which is flexibly associated with the underlying physical storage.
Flexible volumes allow the boundaries between aggregates and volumes to be flexible, such that there does not have to be a one-to-one relationship between a flexible volume and an aggregate. An aggregate can contain multiple flexible volumes. Hence, flexible volumes can be very flexibly associated with the underlying physical storage block characteristics. Further, to help reduce the amount of wasted storage space, any free data block in an aggregate can be used by any flexible volume in the aggregate. A flexible volume can be grown or shrunk in size. Furthermore, blocks can be committed to flexible volumes on-the-fly from available storage.
One feature which is useful to have in a storage server is the ability to create a read-only, persistent, point-in-time image (RPPI) of a data set, such as a volume or a LUN, including its metadata. This capability allows the exact state of the data set to be restored from the RPPI in the event of, for example, a catastrophic failure of the storage system or data corruption. The ability to restore data from an RPPI provides administrators with a simple mechanism to revert the state of their data to a known previous point in time as captured by the RPPI. Typically, creation of an RPPI or restoration from an RPPI can be controlled from a client-side software tool. An example of an implementation of an RPPI is a Snapshot™ generated by SnapDrive™ or SnapManager® for Microsoft® Exchange software, both made by NetApp®. Unlike other RPPI implementations, NetApp Snapshots do not require duplication of data blocks in the active file system, because the active file system can include pointers to data blocks in a Snapshot, for any blocks that have not been modified since the Snapshot was created.
One problem with the known prior art is that there is no way to create an RPPI of multiple volumes in a single atomic operation. Consequently, if an administrator wanted to acquire an RPPI of all volumes stored by a storage server (or at east more than one volume) at a given point in time, he would have to initiate or program a separate RPPI operation for each volume. That is because each of the volumes is designed as an independent, separately managed set of data. Having to initiate or program a separate RPPI operation for each volume can be time-consuming and burdensome, since there can be many volumes maintained by a given storage server.

Concurrent creation of persistent point-in-time images of multiple independent file systems


A circuit for limiting a power current from a power-controlling pass device, the power-controlling pass device being coupled to a supply voltage, comprises the following. A sense device is coupled to the supply voltage with the sense device being configured to draw a sense current that is proportional to the power current. A current mirror is coupled to the sense device and the supply voltage through a low impedance node, the current mirror being configured to draw a mirror current through the low impedance node that is relative to the sense current. A limiting device is coupled to the supply voltage, the power-controlling pass device, and the low impedance node, the limiting device being configured to limit the power current according to a voltage difference between the low impedance node and the supply voltage.

1. Field of the Invention
The invention relates generally to voltage regulators and specifically to limiting the short circuit current in a voltage regulation circuit.
2. The Prior Art
FIG. 1 is a schematic illustrating a prior art voltage regulator circuit. Circuit 10 includes a power-controlling pass device, for example PMOS transistor 15, coupled between supply voltage 20 and output node 25. A stable output voltage Vout over a defined current IL range is produced between output node 25 and ground. The output of amplifier 30 is coupled to the gate of transistor 15, therefore regulating the behavior of transistor 15. Reference resistors 35 and 40 produce a voltage divider input for amplifier 30 and complete a regulation loop created by transistor 15, amplifier 30, and resistors 35 and 40. Capacitor 45 compensates the regulation loop.
Amplifier 30 compares the voltage across resistor 40 with reference voltage Vbg. Output voltage Vout is determined by the combination of reference voltage Vbg and resistors 35 and 40. As current IL increases above its maximum level, amplifier 30 starts to work in a non-liner mode (i.e. saturation) and as a consequence there is a decline the output voltage Vout. The voltage versus current behavior depends on the characteristics of transistor 15. One problem with circuit 10 is that if transistor 10 is large (for example, in order to have good power supply rejection ratio), then amplifier 30 saturates for high values of current IL in a regulator that features low current load range. This means that the regulator presents a very high short circuit current compared to the typical regulator load current. Such short circuit current primarily depends on characteristics of transistor 15 and is not directly controllable.
One solution for the above referenced problem features a switch connected between the gate of transistor 15 and the supply voltage 20, and controlled by the load current value IL. When the current IL is lower than a predetermined threshold the switch is open and the regulator works in normal operation. When IL is higher than the threshold, the switch is closed thus fixing the voltage at the controlling node of transistor 15, and so limiting the short circuit current of the regulator at the selected current threshold. The problem with this approach is that the rapid on-off state sequencing of the switch causes oscillation in circuit behavior.
What is needed is a current limitation circuit based on a simple architecture that provides a predictable output response and does not alter the behavior of the regulator in normal operation.

This patent is subject to a terminal disclaimer.

Method and apparatus for current limitation in voltage regulators


A hydraulic block for a hydraulic assembly of a slip control system of a hydraulic vehicle brake system includes a metal-plastic composite part with a metal part and a further part. The metal part includes sleeve-like brake line ports, sleeve-like valve receptacles, sleeve-like pump receptacles, and pipes as connecting lines. The further part is a plastic part that is injection-molded around the metal part to form the hydraulic block in a cuboid shape.

The disclosure concerns a hydraulic block for a hydraulic assembly of a brake pressure control system of a hydraulic vehicle brake system.
The term "brake pressure control system" means for example a system for controlling a hydraulic brake pressure on external power braking and/or slip control. Slip control systems are for example anti-lock brake systems, traction control systems and driving dynamic control systems, wherein the latter is also known as an electronic stability program and colloquially as an anti-skid system. These slip control systems are conventionally known under the abbreviations ABS, ASR, FDR and ESP. Such brake pressure control systems are well known and are not explained in detail here.
Hydraulic blocks serve for mechanical fixing and hydraulic connection of components of the brake pressure control system. "Connection" here means a hydraulic connection of the components according to a hydraulic circuit diagram of the brake pressure control system. Such components include solenoid valves, hydraulic pumps, check valves, damper chambers, hydraulic accumulators, pressure sensors, an electric motor for driving the hydraulic pumps, and an electronic control unit for controlling the components or for controlling the brake pressure. The electric motor and the electronic control unit are normally arranged on the outside of the hydraulic block. Typically, hydraulic blocks for brake pressure control systems comprise brake line ports, valve receptacles, pump receptacles and receptacles for further components of the brake pressure control system, and connecting lines which connect the brake line ports and receptacles according to the hydraulic circuit diagram of the brake pressure control system. The receptacles are typically blind holes of stepped diameter in which the components are arranged. The brake line ports are typically also blind holes for connection of brake lines, which lead from a brake master cylinder and/or to hydraulic wheel brakes, by means for example of screw or press-in nipples. The components may be fully recessed into their receptacles in the hydraulic block, for example in the case of hydraulic pumps, or partially recessed into the hydraulic block and otherwise protruding from the hydraulic block, such as for example solenoid valves, the hydraulic parts of which are typically arranged in the valve receptacles and the electromechanical parts of which protrude from the hydraulic block. The hydraulic parts of the solenoid valves form the valve itself and are actuated by the electromechanical parts, in particular an armature and a magnetic coil.
Equipped with the components of the brake pressure control system, such a hydraulic block can be described as a hydraulic assembly.
Publication DE 10 2006 059 924 A1 discloses a cuboid hydraulic block for a hydraulic assembly of a brake pressure control system of a hydraulic vehicle brake system with brake line ports, valve receptacles, pump receptacles and receptacles for hydraulic accumulators, damper chambers and pressure sensors.
Normally, such hydraulic blocks are cut from bars with rectangular cross-section made by extrusion of a metal, namely an aluminum alloy, and then machined to remove material. The surfaces of the hydraulic block are milled and the brake line ports, receptacles for the components of the brake pressure control system and the connecting lines are bored. On the outside of the hydraulic block, the connecting lines must be closed pressure-tightly, which is often achieved by press-fitting a sphere.

Hydraulic block for a hydraulic assembly of a brake pressure control system of a hydraulic vehicle brake system


Both enantiomers of optically active 2-alkanol are produced by transesterification reaction of racemic 2-alkanol and aliphatic acid 2,2,2-trichloroethylester in the presence of enzyme derived from Candida antarctica.. Both enantiomers of optically active 2-alkanol, which are useful as starting materials of liquid crystal materials and have optical purity of 99% or more, can be efficiently produced.

As a method for producing an optically active 2-alkanol, several methods, such as an optical resolution method of an ester exchange reaction using enzyme or an optical resolution method using hydrolysis, are known. Specifically, many methods reported in recent years are those for producing compounds having optical purity of more than 90% ee. However, in almost methods, only one of both enantiomers has good purity, but the other has optical purity of less than 80% ee (for example, Tetrahedron Lett., 1995, 36, 6663; Biotechnol. Lett., 1992, 15, 2159).
Further, there are some methods for producing both enantiomers having optical purity of more than 90% ee (for example, Tetahedron Asymm., 1995, 6, 1217; Tetrahedron Lett., 1993, 34, 1367; Japanese Patent Laid-open Publication No. 6-169794). However, in the stereoselectivity, both enantiomers having optical purity of more than 99% ee are unknown.
In optical active 2-alkanol as liquid crystal materials, both enantiomers are necessary, and each optical purity of 99 % ee or more is required. For this reason, hitherto, it has been conducted to use insufficient methods such as recrystallization after leading the compound obtained by optical resolution to its derivative, or repeated enzyme reaction, to provide compounds having optical purity of more than 99% ee.
There are transesterification reactions using the enzyme derived from Candida antarctica (microbiotics) (Tetrahedron Lett., 36(37), 6663-4), or using aliphatic acid trichloroethyl ester (Japanese Patent Publication No. 06-104661). In general, stereoselectivity of the transesterification reaction using an enzyme is influenced by the combination of alcohol, which is a substrate, ester, which is an acylating agent, and the enzyme, so that the suitability is unknown until the reaction is conducted. In all of the said methods, the optical purity is no more than 90% ee.
Accordingly, a simple method for producing optical active 2-alkanol having both enantiomers showing optical purity of more than 99% ee has been desired.

Method for producing an optically active 2-alkanol


There is provided an improved telemetry system for use with implantable devices such as cardiac pacemakers and the like, for two-way telemetry between the implanted device and an external programmer. The system employs highly energy efficient oscillators with encoding circuits for synchronous transmission of data symbols, which symbols form the telemetry carrier. The system provides improved circuits for higher density data encoding of sinusoidal symbols, including improved combinations of BPSK, FSK, and ASK encoding. Embodiments of transmitters for both the implanted device and the external programmer, as well as modulator and demodulator circuits, are also disclosed, and specifically include oscillators which switch capacitors between a tank circuit and a recharge path, the switching being controlled to occur at moments of substantially zero coil current, thereby providing high efficiency operation.

For several decades, electronic devices have been implanted in humans and animals. Such devices are generally used to monitor or regulate the functions of body organs and the like. For example, a pacemaker monitors and regulates heart rate, delivering electrical impulses as required to maintain a satisfactory heart beat. Such implantable devices are powered by batteries which have a finite capacity, and which also present a limitation in terms of available peak power. As a result, there is a significant need to minimize the energy expended during operation of the implantable device, and to reduce the peak power required for special situations such as communications with external devices.
In recent years, implantable electronic device technology has rapidly advanced. Sizes and weights have been dramatically decreasing, while functionality has been increasing. These advances have created a corresponding demand for two-way communication between the implanted electronic device and an external device, generally known as a programmer. For example, in a pacemaker system, the programmer downloads data to the implanted pacemaker, such as operating parameters. Thus, an advantage of modern pacemaker systems is that the physician can re-program various operating parameters, such as rate, pulse level, mode, etc. Likewise, the implantable device up-links data to the programmer for analysis, such as patient data (e.g., average heart rate) or device operational data (e.g., battery voltage). Indeed, the pacemaker is capable of storing significant amounts of data for diagnostic purposes, which data frequently must be transmitted to the programmer for evaluation by the physician. Unfortunately, the increasing need for telemetry has resulted in a corresponding increase in demand on implantable device battery power. The telemetry system uses a significant amount of battery power when operational, which affects lifetime. And potentially more important, the telemetry system may greatly increase the current load on the battery during periods of transmission, to the point where battery peak power availability substantially curtails the possible rate of transfer. Many implantable systems, such as pacing systems, can accumulate and store large amounts of event and operational data, and this creates a need to transfer such data reasonably quickly and efficiently. The more the data transfer rate is limited, the longer the physician is tied up. For these and other reasons, efficient transmitter operation is vitally important to the useful life and communications capability of an implantable device.
Well-known transmitter designs presently in use with implantable devices employ the reflected impedance from a resonating LC circuit to transmit data. In such a design, an external coil is inductively coupled with the coil in the LC circuit within the implanted device. LC circuit transmitters are generally very efficient because of the small amounts of current required to transmit the signal relative to other transmission means, such as RF. However, the bandwidth of such systems has been limited. A basic problem of many such transmitters is that the LC tank resonance frequency and the drive frequency are not inherently matched, and are subject to the accuracy of the components. The coils used are often subject to detuning by metal objects, programmer heads, etc.
In addition to the need for improved efficiency transmitters, there is a need to incorporate improved encoding of a form adaptable to the transmitters, and by which higher data rates can be communicated. One form of data encoding that has come into use is BPSK, biphasic shift keying. By this technique, a portion of the carrier referred to as a "symbol," e.g., a fill cycle of a sine wave, is shifted in phase to one of two states, so as to carry a bit of information. Likewise, for FSK, frequency shift keying, a symbol is shifted in frequency; and for ASK, the amplitude of the symbol is shifted from one level to another. However, present circuits for BPSK, FSK or ASK lack the efficiency desired for implantable-type systems, and are generally lacking in terms of providing high data transfer rates.
In view of the importance of telemetric communications with implanted devices such as pacemakers, a telemetry system that extends the battery life of such devices and/or provides increased bandwidth and greater data transfer rates is very desirable. Such a system would enable longer effective lifetimes for implanted devices, as well as a greater communication capability between the implanted devices and the external programmer. Thus, there is a long-felt need for a more efficient telemetry system for use with implantable devices, and specifically for improved transmitters, data encoding techniques, and decoding techniques.

Implantable device telemetry system and method


The invention relates to a hydrolysis-stable polyester whose thickness is preferably in the range from 0.4 to 500 μm. The film comprises polyester and at least one hydrolysis stabilizer and is distinguished by its low hydrolysis rate. The invention furthermore relates to a process for the production of the film and its use.

Films comprising polyesters in the stated thickness range are sufficiently well known. The disadvantage of unstabilized polyester films, however, is their tendency to hydrolyze, in particular at temperatures above the glass transition temperature of the respective polyester. Here, tendency to hydrolyze is understood as meaning the property of the polyester to undergo hydrolytic degradation under humid conditions, which is evident, for example, from a reduction of the IV or SV value. This is a limiting factor for the use of polyester films, particularly in applications with a relatively high thermal load, such as in film capacitors, cable sheathing, ribbon cables or engine-protection films, but also in long-term applications, such as in glazing and outdoor applications.
The tendency to hydrolyze is particularly pronounced in the case of aliphatic polyesters, but also in the case of aromatic polyesters, such as PBT and PET. If the tendency of PET to hydrolyze becomes too great for the application, it is necessary to rely on the somewhat more hydrolysis-stable PEN or even on other polymers, such as, for example, polyetherimides or polyimides. However, these are substantially more expensive than PET and, for economic reasons, are therefore often not a solution.
It has therefore already been proposed to improve the hydrolysis stability of polyester films by incorporating hydrolysis stabilizers.
The more hydrolysis-stable polyester raw materials which are obtained by using carbodiimides, and fibers and films produced therefrom, are known (U.S. Pat. No. 5,885,709, EP-A-0 838 500, CH-A-621 135). However, films which are produced from such raw materials tend to emit, in gaseous form, both in the production and in subsequent use, isocyanates and other byproducts and degradation products which irritate the mucous membrane or are harmful to health. This is a much greater problem in the case of sheet-like structures, such as a film having a large surface than in the case of injection-molded parts or the like.
Hydrolysis stabilizers based on epoxy groups also lead to hydrolysis stabilization and are described, for example, in EP-A-0 292 251 or U.S. Pat. No. 3,657,191. However, these compounds are based on the production of oxirane rings by means of epichlorohydrin and, inter alia owing to their terminal epoxy groups, tend to eliminate low molecular weight toxic compounds on heating, so that problems similar to those with the use of carbodiimides are associated with the use of these substances. Moreover, their incorporation into the polyester matrix is insufficient, which leads to long reaction times and, in the case of oriented polyester films, to a considerable undesired haze.
Moreover, known hydrolysis stabilizers, such as carbodiimides and other substances, such as those described in EP-A-0 292 251, have the disadvantage that in some cases they lead to considerable increases in molecular weight (increase in viscosity) in the polymer during extrusion and thus make the extrusion process unstable and difficult to control.

Hydrolysis-stable film comprising a polyester with a hydrolysis stabilizer and process for its production and its use


In an optical recording medium comprising a substrate including parallel extending lands and grooves on one surface thereof, the grooves serving as recording tracks, and the lands being formed with prepits, the height HP of the land disposed between the prepit and the groove divided by the height HL of the land in a prepit-free region, both as measured from the groove bottom, i.e., HP/HL ranges from 0.25 to less than 1. This enables to significantly increase the recording density of the medium without a substantial cost increase.

1. Field of the Invention
This invention relates to an optical recording medium.
2. Prior Art
Optical recording media include write-once disks using organic dyes as the recording material such as CD-R and DVD-R and rewritable disks using phase change recording materials such as CD-RW and DVD-RW. These optical recording media have recording layers formed on disk substrates which are provided on the surface with (guide) grooves for tracking and other purposes. Among these media, DVD-R and DVD-RW capable of higher density recording have address information-bearing prepits formed in raised regions (commonly referred to as lands) between adjacent grooves. Optical disks having prepits formed in lands are disclosed, for example, in JP-A 2000-11460 and 11-126372.
In optical recording media having grooves and prepits formed therein wherein the grooves serve as recording tracks, write/read operation is carried out along the grooves. It is believed that write/read characteristics are largely affected by the shape of the grooves and prepits.
The invention pertains to an optical recording disk of the structure comprising a substrate provided with grooves and lands and a recording layer containing an organic dye thereon, the grooves serving as recording tracks and the lands being formed with prepits. The disk substrate with grooves and lands is often prepared by the injection molding of resin using a stamper. The inventors attempted to prepare such disk substrates by changing many parameters including those associated with the stamper manufacturing step.
Now a common process for the preparation of a disk substrate is described. The disk substrate is prepared by the injection molding of resin using a stamper bearing a negative prepit and groove pattern. The stamper is often formed of nickel. In order to manufacture the stamper, an optical disk master is first prepared. The following process is generally employed for preparing the optical disk master. First, a photoresist layer is applied on the surface of a glass substrate. The photoresist layer is exposed to a laser beam to form a latent image of the desired pattern, followed by development.
Using the optical disk master, a stamper is manufactured usually by the following process. First, to impart electric conductivity to the surface of the photoresist layer on the optical disk master, a metal thin film of nickel or the like is formed as by sputtering or electroless plating. Electroforming is then effected to deposit a film of nickel or the like on the metal thin film. Then the laminate of the metal thin film and the electroformed film is stripped from the photoresist layer. The laminate is ready for use as the stamper master. This stamper master may be used as the stamper directly, although a stamper mother may be prepared from the stamper master and used as the stamper. The stamper mother is prepared by electroforming a film on the surface of the stamper master and stripping the electroformed film. It is recommended to previously oxidize the surface of the stamper master so that the electroformed film may be readily stripped therefrom. Alternatively, a stamper child may be similarly prepared using the stamper mother and used as the stamper.
In the process of preparing an optical disk master, the minimum width of the latent image pattern formed in the photoresist layer is limited by the diameter of a laser beam spot. The beam spot diameter w is represented by w=xcex/NA wherein xcex is the wavelength of the laser beam, NA is the numerical aperture of an objective lens in an optical system. In forming a latent image pattern corresponding to the groove, the photoresist layer is helically scanned with the laser beam.
When prepits are to be formed between grooves, two laser beams were used in the step of forming the latent image pattern. One laser beam is continuously irradiated to form a groove pattern and the other laser beam is intermittently irradiated to form a prepit pattern. The laser beam defines a beam spot having a Gaussian intensity distribution. In the event that the track pitch is narrowed in order to achieve a higher recording density, the perimeters of two laser beams overlap (that is, the skirts of two Gaussian distributions overlap) near the region which is simultaneously exposed to two laser beams, that is, the prepit-forming region. The dose of exposure can exceed the threshold in the overlapped area. The area where the dose of exposure has exceeded the threshold is removed upon development so that the land is lowered in height. A lowering of the land leads to increased errors.
To prevent the land from lowering its height, the size of the beam spot may be reduced in accordance with the distance between the groove and the prepit. This is achieved by either reducing the wavelength of a laser beam or increasing the numerical aperture of an objective lens in a laser beam recorder. As to the laser wavelength, a blue laser of short wavelength has been used in practice. Then, a laser beam of a shorter wavelength, for example, in the ultraviolet region must be used. On use of a laser beam in the ultraviolet region, however, optical components including the objective lens should be changed to those capable of complying with the ultraviolet region. This gives rise to a serious problem that a substantial modification of the system is needed.
An object of the invention is to provide an optical recording medium having grooves serving as recording tracks and prepits formed between adjacent grooves wherein the potential occurrence of errors due to an increase of recording density is minimized without a substantial cost increase.
The invention provides an optical recording medium comprising a substrate including lands and grooves extending substantially parallel on one surface thereof, the grooves serving as recording tracks, and the lands being formed with prepits. The height HP of the land disposed between the prepit and the groove and the height HL of the land in a prepit-free region, both as measured from the bottom of the groove in a cross section perpendicular to the substrate surface, satisfy the relationship: 0.25xe2x89xa6HP/HL less than 1.
In a preferred embodiment, the grooves are arranged at a pitch P, and the distance from the center of the prepit to the centerline of one adjacent groove is r, the pitch P and the distance r satisfying the relationship: 0.4xe2x89xa6r/Pxe2x89xa60.6.
The optical recording medium may further include a recording layer containing an organic dye on the substrate surface.

Optical recording medium having a land height ratio


A preparation method for a novel composite anode based on nitrogen-doped charcoal of sludge and porous volcanic, and a microbial fuel cell, relating to the technical field of resource utilization of new materials, new energy and wastewater. Active sludge is prepared into porous nitrogen-doped charcoal by using a nitrogen high-temperature pyrolysis baking method; and then, surface minerals are removed by using an acidification method to improve the electrical conductivity of the charcoal; finally, surface charcoal loading is performed by taking volcanic granules as a carrier to prepare and form nitrogen-doped charcoal granules on a volcanic surface. The novel granules have high porosity, high electrical conductivity and large specific surface area, and fully meet the performance requirement of the anode material of the microbial fuel cell. The anode of the novel nitrogen-doped porous charcoal can increase the loading capacity of electricity-producing bacteria and microorganisms of the anode of the microbial fuel cell, and improve the conversion rate of biomass energy in wastewater; by virtue of low-resistance characteristics, the electron transfer efficiency is also improved, and finally, the power of the microbial fuel cell is enhanced, so that both wastewater treatment and recycling and efficient biological power generation are achieved.

In recent years, MFC technology has attracted wide attention because of the rapid development of new energy technology. Much organic matter are concluded in domestic sewage and industrial wastewater, these water can be used as the source of MFCs. When the wastewater is treated with high quality, the biomass energy in the wastewater is converted into electrical energy, and the clean energy is producted in the process, which is an efficient way to develop new energy. MFC anode directly involved in microbial catalysis, the load directly determines the efficiency of biomass conversion, and the electrode material is the electricigens electron transfer medium, so the particle filled anodic chamber properties obviously plays a decisive role in the fuel cell power generation.
The basic performance requirements of the anode material for MFC are low resistivity, high total porosity and large specific surface area. The commonly used anode materials include carbon cloth, graphite particles, activated carbon particles, graphite rod, graphite felt, carbon brush, graphite disc and so on. These materials have good conductivity, higher surface roughness, suitable electricigens attached and electron transfer. However, with the microbial metabolism and the increase of anodic biofilm thickness, the specific surface area is reduced, and the electron transfer efficiency is significantly reduced, resulting in the rapid reduction of microbial fuel cell potential. At present, the effective way to solve this technical problem is to improve the specific surface area of the anode material and improve the conductive properties of the material. The interface between microorganism and electrode deter mines the speed and amount of electron transfer. Therefore, the interface between microorganism and electrode is more important than the inner space of the electric carrier which is not utilized. The internal carrier of microorganism has little effect on electricity production. The cost of MFC electrode restricts the practical application of the technology. Therefore, the preparation of low-cost anode materials and cathode electrodes is an important content to promote the application of MFCs in water treatment industry. Compared with all kinds of high cost carbon anode materials, the preparetion of the novel cheap biochar based biosludge and surface modification of volcanic material with large pore and solid material is significant for the prepare composite electrodes of cheap carbon and inorganic mineral.
Under the condition of the isolation of oxygen and the filling of nitrogen, the activated biological sludge was made into the novel porous biological carbon doped nitrogen by using high temperature pyrolysis and baking technology, and then the conductivity is improved by acidification. Using self deposition, The prepared carbon materials was loaded on the surface of the carrier volcano rock particles, realizing the preparetion of biochar.
The new MFC anode filling materials with the high specific surface area and good conductivity of the patent can significantly enhance the load of electricigens, the surface of biochar formed by high temperature baking is smooth, easy to fall off biofilms, and promotes the transfer of electrons. It can significantly enhance the cell potential and coulombic efficiency.

Preparation of a new type of composite anode and microbial fuel cell based on nitrogen doped biological carbon and porous volcanic rocks


A method of arranging an optical pickup system on a deck of an optical recording and/or reproducing apparatus, which enables detection of a tracking error signal using one photodetector based on a three-beam method and by a differential phase detection method. The optical pickup system includes a light source, a diffractive optical element which diffracts a light beam incident from the light source and splits the same into at least three beams, a plate-type beam splitter which changes a propagation path of the light beam, and a photodetector including at least one main photodetector having at least four sections and a plurality of sub-photodetectors. The optical pickup system is constructed so as to have a reflecting mirror redirect the propagation path of the light beam emitted from the light source toward a recording medium. The method of arranging the optical pickup includes, where the propagation path of the light beam transmitted through the plate-type beam splitter to the photodetector is an optical path axis, arranging the optical pickup system so as to have the optical path axis tilted with respect to an axis in a tangential direction of the recording medium and have the photodetector placed away from a rotation center of a motor that rotates the recording medium, and selectively optimizing the arrangement of the photodetector to detect a tracking error signal by the differential phase detection method.

1. Field of the Invention
The present invention relates to a method of arranging an optical pickup system and an optical recording and/or reproducing apparatus having the arranged optical pickup system.
2. Description of the Related Art
FIG. 1 shows an example of the optical configuration of an optical pickup. Referring to FIG. 1, the optical pickup includes a light source 3 which emits light of a predetermined wavelength, a plate-type beam splitter 5 which changes a propagation path of a light beam emitted by the light source 3, an objective lens 7 which focuses an incident light beam to a spot on a recording surface of an optical disc 1, and a photodetector 9 which detects an information signal and an error signal by receiving the light beam that is reflected from the recording surface of the optical disc 1 and has sequentially passed through the objective lens 7 and the plate-type beam splitter 5. The optical pick-up, as shown in FIG. 4, is arranged such that all components of the optical pickup system, except for the objective lens 7, are approximately parallel to the optical disc 1 by redirecting the optical path by 90 degrees with a reflecting mirror 2. In FIG. 1, reference numerals 4, 6, and 8 refer to a grating, a collimating lens, and a concave lens.
The grating 4 is disposed between the light source 3 and the plate-type beam splitter 5 to diffract the light beam emitted from the light source 3 into 0th-order and ±1st-order beams, so as to detect a tracking error signal by a three-beam method.
FIG. 2 illustrates that in a normal state, a main light beam corresponding to the 0th-order diffracted light beam passing through the grating 4 is focused on a main track 1a as a main light beam spot S0, while sub-beams corresponding to the ±1st-order beams diffracted by the grating 4 are centered as sub-beam spots S1 and S2 approximately symmetrical to radial and tangential directions relative to the main light beam spot S0, on positions slanted with respect to the main track 1a. The main light beam is reflected/diffracted from the optical disc 1 to produce a reflected/diffracted light beam which will be described later. In FIG. 2, a dotted line is used to distinguish one track from another.
Where the grating 4 is provided to detect a tracking error signal by the three-beam method, the photodetector 9 may comprise a main photodetector and a pair of sub-photodetectors to detect a main light beam and sub-beams reflected from the optical disc 1, respectively. The collimating lens 6 is disposed between the plate-type beam splitter 5 and the objective lens 7 so as to convert a divergent light beam emitted from the light source 3 into a parallel light beam. The concave lens 8 is positioned between the plate-type beam splitter 5 and the photodetector 9 to spread out a light beam focused on the photodetector 9. The concave lens 8 is inclined in a direction opposite to the direction in which the plate-beam splitter 5 is tilted so as to remove coma aberrations on a light beam passing through the plate-type beam splitter 5.
In the optical pickup described above, the light beam emitted from the light source 3 is reflected by the plate-type beam splitter 5 and proceeds toward the optical disc 1, and the light beam reflected from the optical disc 1 transmits through the plate-type beam splitter 5 and travels to the photodetector 9. Hereinafter, an axis of propagation path of the light beam transmitted through the plate-type beam splitter 5 to the photodetector 9 is called an optical path axis c.
FIG. 3 illustrates that since the plate-type beam splitter 5 is tilted with respect to the optical path axis c, an optical length in a horizontal direction h of the light beam transmitted through the plate-type beam splitter 5 remains constant regardless of an incident location of the light beam on the beam splitter 5, while an optical length in a vertical direction v varies depending on the location. This causes astigmatism due to difference in focal points in the horizontal and vertical directions h and v. Here, an axis in the vertical direction v is one axis, i.e., a major axis of an oval light beam suffering from astigmatism, and an axis parallel to the vertical axis is an astigmatism axis.
Thus, the optical pickup of FIG. 1 arranged so that the light beam reflected from the optical disc 1, which is transmitted through the plate-type beam splitter 5 to the photodetector 9, can detect a focus error signal using an astigmatism induced in the light beam transmitted through the plate-type beam splitter 5.
A motor (not shown) to rotate the optical disc 1 and an optical pickup system are mounted on a deck of an optical recording and/or reproducing apparatus, such as a disc driver or a disc player, to record and/or reproduce information on and/or from the optical disc 1, using light. Since the size of the deck affects the overall size of the optical recording and/or reproducing apparatus, a particular arrangement of the optical pickup system with respect to the deck is very important, for example, in making the optical recording and/or reproducing apparatus compact.
In the case of detecting a focus error signal by an astigmatism method using the plate-type beam splitter 5 as an optical path changer instead of a separate astigmatism lens, as shown in FIG. 1, the photodetector 9 is necessarily oriented at 45 degrees to detect the focus error signal by the astigmatism method, where the optical pick system is arranged so as to have the optical path axis c parallel to a tangential direction. Here, the tangential direction refers to a direction of a series of pits or marks formed along a track on the optical disc 1.
To detect a focus error signal by an astigmatism method, as well as a tracking error signal by a three-beam method, the photodetector 9 includes a main photodetector having four or more sections, and a pair of sub-photodetectors on either side thereof. Where the photodetector 9 rotates at 45 degrees to detect a focus error signal by an astigmatism method, using astigmatism occurring at the plate-type beam splitter 5, sub-beams used to detect the tracking error signal by the three-beam method may not be received by the sub-photodetectors. Rather, the sub-beams deviate from the sub-photodetectors.
Thus, where the photodetector 9 rotates at 45 degrees, it is not possible to detect a tracking error signal by the three-beam method since the sub-beams are not received onto the sub-photodetectors. Furthermore, this eventually increases the space required to mount the photodetector 9 on the deck of an optical recording and/or reproducing apparatus since a height needed to install the photodetector 9 corresponds to a length of a diagonal line of the photodetector 9.
To solve these problems, where the optical pick-up system includes the plate-type beam splitter 5 on the deck of the optical recording and/or reproducing apparatus and is arranged to two-dimensionally arrange all components of the optical pickup system, except the objective lens 7, approximately parallel to the optical disc 1 by redirecting an optical path by 90 degrees with the reflecting mirror 2, the optical pickup system is necessarily arranged so as to have the optical path axis c inclined at 45 degrees with respect to a tangential direction. Here, the tangential direction perpendicular to the radial direction refers to a direction of a series of pits or marks formed on the optical disc 1.
However, it is difficult to arrange the optical pickup system so as to have the optical path axis c be tilted relative to the tangential direction by 45 degrees due to the size of a motor mounted on the deck to rotate the optical disc 1. In general, the optical path axis c is inclined at an angle of less than 35 degrees relative to the tangential direction to avoid contact with the motor.
For at least the reasons provided above, as shown in FIG. 4, in a conventional method, an optical pickup system is arranged so as to have an optical path axis c1 inclined with respect to a tangential direction at a predetermined angle E, for example, 35 degrees, and a photodetector 9 is placed at a location close to a rotation center Mc of a motor (not shown) mounted on a deck that rotates an optical disc 1.
Reference numeral 2 in FIG. 4 refers to a reflecting mirror that redirects a proceeding path of a light beam emitted from a light source 3 toward the optical disc 1.
Since the optical pickup system is arranged so as to have an angle of the optical path axis c1 relative to the tangential direction less than 45 degrees, for example, 35 degrees, the photodetector 9 comprises, as shown in FIG. 5, a main photodetector 9a that is split into four sections by lines d1 and d2 having oblique 5–10 degrees with respect to axes of tangential direction and radial direction, respectively, and a pair of sub-photodetectors 9b and 9c.
In FIGS. 5, 7, and 8A–8C, an axis of the tangential direction can correspond one-to-one to a tangential direction on the optical disc 1, while an axis of the radial direction can correspond one-to-one to a radial direction on the optical disc 1.
The use of an optical pickup system arranged as shown in FIG. 4 and a photodetector constructed as shown in FIG. 5 achieves the same effect as when using a typically split photodetector for the photodetector 9 and rotating the photodetector at 45 degrees. Here, the typically split photodetector refers to a photodetector in which a main photodetector is split to be rectangular or square.
In FIG. 4, θ refers to an angle between the optical path axis c1 and the axis in the tangential direction. The optical path axis c1 forms an angle 90°-θ with the axis in the radial direction that transverses through the rotation center Mc of the motor mounted on the deck that rotates the optical disc 1.
As shown in FIG. 4, where the photodetector 9 is placed toward the rotation center Mc of the motor, the light source 3 is placed at a location farther away from the rotation center Mc than the photodetector 9 since it is not possible to position the light source 3 near the rotation center Mc due to space restrictions. The use of an optical pickup system arranged as shown in FIG. 4 and a photodetector constructed as shown in FIG. 5 allows detection of a focus error signal by an astigmatism method employing astigmatism that occurs at the plate-type beam splitter 5 used as an optical path changer, as well as detection of a tracking error signal by a three-beam method.
Thus, the conventional method of arranging the optical pickup facilitates detection of a tracking error signal by a three-beam method while making an optical recording and/or reproducing apparatus compact by reducing the space required to install the optical pickup system, as compared to a case of arranging the optical pickup system so that the optical path axis c1 is parallel to an axis of a tangential direction.
The problem with the conventional method of arranging the optical pickup system (so that the optical path axis c1 is tilted relative to the axis of the tangential direction and the photodetector 9 is placed near the rotation center Mc of the motor) arises where a single photodetector is used to detect a tracking error signal by a differential phase detection (DPD) method and a tracking error signal by a three-beam method.
CD and DVD compatible optical pickups having a single light source and a single photodetector, or having two light sources and a single photodetector, require detection of tracking error signals using both DPD and three-beam methods.
Typically, in the case of CDs, a tracking error signal detected by the three-beam method is used to perform a tracking control, whereas in DVDs, a tracking error signal detected by the DPD method is used to do the same.
However, the conventional method of arranging the optical pickup system makes it difficult to detect tracking error signals by both DPD and three-beam methods using a single photodetector based on the following aspects.
FIG. 6 illustrates that where a light beam spot is formed in a pit P (or a mark) on the optical disc 1, diffraction occurs in an edge of the pit P. Thus, as shown in FIG. 7, a light beam reflected/diffracted from the pit P on the optical disc 1 has a structure in which a 0th-order diffracted beam Lm and ±1st-order diffracted beams Ls generated by diffraction on the edge of the pit P partially overlap each other. In FIG. 7, a main light beam corresponding to the 0th-order beam and sub-beams corresponding to the 1st-order beams diffracted by the grating 4 have a partially overlapped structure since those light beams are reflected from the optical disc 1 and diffracted by the pit P. However, a reflected/diffracted light beam used to detect a tracking error signal by a DPD relates to the main light beam. Accordingly, only the reflected/diffracted light beam for the main light beam will be described hereinafter.
FIG. 7 shows a reflected/diffracted light beam (the reflected/diffracted light beam before entering the plate-type beam splitter 5) that passes through the objective lens 7 and travels toward the collimating lens 6. FIGS. 8A and 8B show the reflected/diffracted beam transmitted through the plate-type beam splitter 5. That is, FIG. 8A shows the optical path axis c1 and reflected/diffracted light beam when viewed facing the plate-type beam splitter 5, while FIG. 8B shows the optical path axis c1 and reflected/diffracted light beam when viewed facing the photodetector 9. The difference in locations of the optical path axis c1 and overlapped portions of the reflected/diffracted light beam is due to the fact that the reflected/diffracted light beam is observed in opposite directions.
When compared among the reflected/diffracted light beams in FIGS. 7, 8A, and 8B, the reflected/diffracted light beam before being transmitted through the plate-type beam splitter 5 is symmetrically transformed into that of after being transmitted through the plate-type beam splitter 5 with respect to the optical path axis c1 (or astigmatism axis). This is because the reflected/diffracted light beam transmitted through the plate-type beam splitter 5 undergoes the symmetric transformation with respect to the optical path axis c1 due to astigmatism that causes focal point variations in vertical and horizontal directions.
The reflected/diffracted light beam is symmetrically transformed with respect to the optical path axis c1 or astigmatism axis. However, for ease of understanding and illustration, the optical path axis c1 is used herein as the axis of symmetric transformation of the reflected/diffracted light beam. The astigmatism axis refers to the vertical axis in the plate-type beam splitter 5 and is inclined 45 degrees relative to the optical path axis c1 since the plate-type beam splitter 5 is tilted 45 degrees with respect to the same.
To detect a tracking error signal by the DPD method, the 0th-order beam Lm and the ±1st-order beams Ls reflected and diffracted by the optical disc 1 are evenly received by four section plates A–D of the main photodetector 9a (FIG. 5) in a normal state, i.e., where a light beam spot is formed at a center of a track on the optical disc 1.
As is evident in FIG. 8C illustrating a case in which the reflected/diffracted light beam of FIG. 8B is received by the main photodetector 9a shown in FIG. 5, a dividing line d1 of the main photodetector 9a shown in FIG. 5 is not identical to a bisector axis Ic for the reflected/diffracted light beam, and they are located in the opposite direction with respect to an axis in the tangential direction. This makes it impossible to detect a tracking error signal by the DPD method without rotation of the photodetector 9. That is, to enable detection of a tracking error signal using the DPD method, the photodetector 9 is required to be rotated at a significantly large angle.
Here, the bisector axis Ic for the reflected/diffracted light beam is defined as an axis that passes through the center of the reflected/diffracted light beam received by the main photodetector 9a and divides the ±1st-order diffracted beams Ls into two equal parts in a normal state, in which the sizes of regions where the ±1st-order diffracted beams Ls overlap the 0th-order diffracted beam Lm are identical and the overlapping regions are symmetrical with respect to the axis in the tangential direction.
In FIG. 8C, the main photodetector 9a indicated by a solid line does not rotate, while that indicated by a dotted line rotates so that the dividing line d1 is identical to the bisector axis Ic for the reflected/diffracted light beam in order to detect a tracking error signal by the DPD method.
As illustrated in FIG. 8C, in the case of applying the conventional arrangement method, the photodetector 9 needs to rotate at an angle derived by adding the absolute value of an angle θ1 at which the dividing line d1 of the main photodetector 9a is inclined relative to the axis in the tangential direction to the absolute value of an angle θ2 at which the bisector axis Ic for the reflected/diffracted light beam is inclined relative to the axis in the tangential direction.
Where the optical pickup system is arranged so that the optical path axis c1 forms an angle of 35 degrees or less with respect to the axis in the tangential direction, and the optical pickup is arranged toward the central axis Mc of the motor from the right as shown in FIG. 4 according to the conventional method, the bisector axis Ic for the reflected/diffracted light beam forms an angle of approximately 10 degrees or more with respect to the axis in the tangential direction. Since the dividing line d1 of the main photodetector 9a in the photodetector 9 is tilted at approximately 5–10 degrees with respect to the axis in the tangential direction in the opposite direction to the bisector axis Ic, the photodetector 9 has to rotate at an angle of 15 degrees or more for detection of a tracking error signal using the DPD method.
For example, where the bisector axis Ic forms an angle of approximately 10 degrees with respect to the axis in the tangential direction, since the optical path axis c1 of the optical pickup system is tilted 35 degrees with respect to the axis in the tangential direction, where the dividing line d1 of the photodetector 9 is inclined 6 degrees relative to the axis in the tangential direction, the photodetector 9 needs to rotate at approximately 16 degrees. In another example, where the dividing line d1 is inclined 10 degrees relative to the axis in the tangential direction, the photodetector 9 has to rotate by 20 degrees.
Although FIG. 8C only shows the main photodetector 9a for simplification, as the main photodetector 9a rotates, the entire photodetector 9 shown in FIG. 4 rotates.
Where the optical pickup system is arranged so that the optical path axis c1 is tilted with respect to the tangential direction and the photodetector 9 is placed toward the rotation center Mc of the motor according to the conventional method as illustrated in FIG. 4, there are many difficulties in detecting tracking error signals by DPD and three-beam methods using one photodetector 9.
That is, to detect a tracking error signal by the DPD method, the phtodetector 9 has to rotate to an extent to prevent deviation of sub-beams that detect a tracking error signal by a three-beam method from the sub-photodetectors 9b and 9c. Angles of rotation available are normally less than 15 degrees.
In the case of arranging the optical pickup system as shown in FIG. 4, since the reflected/diffracted light beam rotates in the direction in which the bisector axis Ic moves away from the dividing line d1 of the main photodetector 9a with respect to the optical path axis c1, it may be necessary to rotate the photodetector 9 at an angle of 15 degrees or more as shown in FIG. 8C so as to enable detection of a tracing error signal by the DPD method, by making the dividing line d1 of the main photodetector d1 identical to the bisector axis Ic for the reflected/diffracted light beam. Where the photodetector 9 rotates at 15 degrees or more in this manner, the sub-beams tend to deviate from the sub-photodetectors 9b and 9c, thereby making it difficult to detect a tracking error signal by the three-beam method.
That is, with the conventional arrangement of the optical pickup system, as shown in FIG. 4, it is difficult to detect tracking error signals using both DPD and three-beam methods with a single photodetector.

Method of arranging optical pickup system and optical recording and/or reproducing apparatus having the arranged optical pickup system


Systems, methods, and devices of the various embodiments may provide a portable power system for powering small devices that may be small, may be compact, may provide continuous power, and may be lightweight enough for an astronaut to carry. Various embodiments may provide a compact, thermionic-based cell that provides increased energy density and that more efficiently uses a heat source, such as a Pu-238 heat source. Nanometer scale emitters, spaced tightly together, in various embodiments convert a larger amount of heat into usable electricity than in current thermoelectric technology. The emitters of the various embodiments may be formed from various materials, such as copper (Cu), silicon (Si), silicon-germanium (SiGe), and lanthanides. Various embodiments may be added to regenerative thermionic cells with multiple layers to enhance the energy conversion efficiency of the regenerative thermionic cells.

Astronauts with portable tools, rovers, and other deployable devices and systems require either imbedded batteries or cable connection to power source to function. Both methods require contact with a central power source for recharge of batteries or power feed through cable. Ideally, a power source for portable equipment and deployable systems must be small, compact, provide continuous power, and be lightweight enough for an astronaut and rovers to carry. Batteries can meet some of those requirements, but do not meet the continuous power requirement. Batteries have short or limited lifetimes and required constant replacement and recharging. All deep space probes require simple, small, light, long-term operational, and inexpensive power sources. However, no other choices are available but use of large, bulky, heavy, and costly radioisotope thermoelectric generators (RTGs) appears only an option regardless of enhancing capability and functionality of the probes. Moreover, the conversion mechanism, thermoelectric (TE) generator, is very inefficient, only operating at approximately 7% efficiency, and RTGs require a large quantity (e.g., kilogram level) of plutonium-238 (Pu-238), a difficult and expensive materials to produce in large amounts. Solar cells are unusable for deep space operations where light density is too low and the efficiency of solar cells is rather low, requiring impractically large flat panel arrays to harvest usable amounts of power. Thus, solar cells are not suitable for powering astronaut systems and tools.
No continuous long-term operational, portable power system currently exists for powering small devices. Ideally, a portable power system for powering small devices must be small, compact, provide continuous power, and be lightweight enough for an astronaut to carry. Batteries can meet some of those requirements, but do not meet the continuous power requirement. RTGs can meet the continuous power requirement, but none of the other requirements. Solar cells do not meet the continuous power requirement or the small, compact, and lightweight requirements. The lack of the current existence of a continuous, portable power system for powering small devices limits both manned and unmanned space missions.

Portable miniaturized thermionic power cell with multiple regenerative layers

UNITED STATES OF AMERICA AS REPRESENTED BY THE ADMINISTRATOR OF NASA


A ventilator has an inspiratory unit and an expiratory valve for regulating a flow of breathing gas and a control unit for controlling the inspiratory unit and the expiratory valve. In order to facilitate the opening of collapsed alveoli in the lungs, the control unit controls the inspiratory unit and the expiratory valve to generate a recruitment phase with an elevated basic pressure for the flow of breathing gas upon which a number of breaths is superimposed at a faster breathing rate.

1. Field of the Invention
The present invention relates to a ventilator of the type having an inspiratory unit and an expiratory valve for regulating a flow of breathing gas, and a control unit for controlling the inspiratory unit and the expiratory valve.
2. Description of the Prior Art
Mechanical ventilation is employed to control or support a patient's breathing. Breathing gas at a positive pressure is supplied to the patient. In many instances, ventilation is a vital necessity for the patient, however, the treatment in itself is not without risks. Numerous studies of animals suggest that ventilation can initiate or aggravate lung damage. A major contributory reason for this is the mechanical stress to which the pulmonary system may be subjected during ventilation. In particular, damage can develop or be aggravated when alveoli in the lungs cyclically open and collapse during inspiration and expiration.
Moreover, some patients suffer from such severe conditions that using a treatment that can cause some damage to the lungs is the only way to save the patient's life.
One way to prevent alveolar collapse is to impose a positive pressure on the lungs, even during expiration, with a positive end-expiratory pressure (PEEP). However, PEEP cannot be set too high, since a high PEEP can subject the lungs to harmfully high pressure during inspiration. An excessive inspiratory pressure can impede blood perfusion in the lungs (causing poorer oxygenation of the blood) and even inflicting damage to pulmonary tissue.
Recruitment phases can be employed instead of a constantly high PEEP. During a recruitment phase, the pulmonary alveoli are opened with a pressure (usually higher than the normal inspiratory pressure for the patient), enabling them to remain open when exposed to a lower pressure during a subsequent period of treatment. The recruitment phase is repeated as needed.
A number of procedures are known for instituting the recruitment phase. One is often referred to as the 40/40 method. This means that the lung is subjected to a pressure of about 40 cmH2O for up to 40 seconds.
This is a static procedure and rather hard on the lung and the patient, but it is a simple maneuver producing clear results in the form of improved oxygenation of the blood.
Another procedure involves the use of a number of brief pressure pulses, e.g. three, each lasting 15 seconds.
In principle, the effect is the same as in the aforementioned instance. However, static methods have a major shortcoming in the buildup of carbon dioxide in the lungs during the recruitment phase.
A third known procedure involves a successive increase in pressure in the lungs during, in principle, normal breaths until a satisfactory degree of opening is achieved.
This is without doubt the easiest method on the lung and patient, but it is highly demanding and difficult for staff to implement.


A semiconductor device having good production stability and excellent in a contact property between an antireflection film on an Al contained metal film and a conductive plug. The device includes a substrate, an insulating interlayer, and a multi-layer structure. The insulating interlayer is formed in the upper portion of the substrate. The structure is provided on the insulating interlayer. A Ti film, a first TiN film, an AlCu film, a Ti film, a second TiN film, and an etching adjustment film are sequentially formed in the structure. The device includes an insulating interlayer and a conductive plug. The insulating interlayer is provided on the insulating interlayer and the structure. The conductive plug penetrates the insulating interlayer and the etching adjustment film, and an end surface of the conductive plug is located in the second TiN film. The conductive plug includes a Ti film, a TiN film, and a W film.

1. Field of the Invention
The present invention relates to a semiconductor device and a manufacturing method thereof.
2. Description of the Related Art
For example, the conventional methods of manufacturing a semiconductor device are disclosed in Japanese Laid-Open patent publication Nos. 2002-190520 and 2000-235973.
In the above conventional methods of manufacturing a semiconductor device manufacturing methods, an antireflection film is provided on an aluminum interconnection which is a lower layer, a plasma nitride film which works as a stopper during etching is formed on the antireflection film, and an interlayer film which is an insulating film is formed on the plasma nitride film. When a via is formed in the insulating film, first etching is performed on condition that etching selectivity can be ensured between the insulating film and the plasma nitride film. Then, the plasma nitride film is overetched in second etching to make a via hole from which the antireflection film is exposed.
An example of the conventional semiconductor device is disclosed in Japanese Laid-Open patent publication No. 2002-319620. FIG. 8 is a view for explaining a method of making a contact hole shown in Japanese Laid-Open patent publication No. 2002-319620. In the method of making the contact hole, dry etching is performed by using a resist 34 as a mask, and thereby a contact hole 38 is made in a thick insulating interlayer 32 on a lower diffusion layer 24 formed on a surface of a silicon substrate 22 while a contact hole 36 is made in a thin insulating interlayer 32 on a lower interconnection layer 26 formed on an oxide layer 30. Although only the insulating interlayer 32 is etched in making the contact hole 38, the insulating interlayer 32 and an etching delay layer 28 are etched in making the contact hole 36. Then, the resist 34 is removed and post-dry-etching treatments (cleaning and the like) are performed (not shown).
Reactive ion etching in which anisotropic etching can be performed is used as the dry etching in making the contact holes 36 and 38. This is because the anisotropic etching is desirable in making the contact holes 36 and 38 such that the etching does not progress in a lateral direction. However, due to the anisotropic etching, it is difficult that only the insulating interlayer 32 (SiO2 or the like) is etched without etching a lower electrode layer (TiN, AlCu, Ti or the like) 26. In this case, Japanese Laid-Open patent publication No. 2002-319620 states that the formation of the etching delay layer 28 is particularly useful.
However, conventionally, there is room for improvement in the following points.
First, the etching for making the via is performed in twice in the semiconductor device manufacturing methods disclosed in Japanese Laid-Open patent publication Nos. 2002-190520 and 2000-235973. Therefore, the number of production processes and a process time are increased in making the via, and there is still room for improvement from the view points of productivity and the production stability.
Second, in the method of making the contact hole disclosed in Japanese Laid-Open patent publication No. 2002-319620, the resist 34, the insulating interlayer 32, and the etching delay layer 28 are sequentially etched to form the contact hole 36 which reaches an upper surface of the lower interconnection layer 26. However, because the lower interconnection layer 26 is exposed to a bottom portion of the contact hole 36, sometimes Al is eluted in a chemical solution in performing post-etching organic cleaning to the inside of the contact hole with the chemical solution when the lower interconnection layer 26 is made of AlSi. Thus, sometimes the metal elution of the lower interconnection layer 26 into the chemical solution causes a decrease in contact property between the lower interconnection and the via plug provided in the contact hole.

Semiconductor device and manufacturing method thereof