A laser warning receiver (LWR) having an ability to not only detect a low power level laser source, such as a pulse train emitted by a laser beam rider, but to also provide a high angular resolution in determining the angle of arrival of that pulse train. The receiver includes a lens/filter arrangement for a large area photodetector to detect an incoming signal from an emitting source and a high gain amplifier to amplify the signal which is then applied to a synchronization generator that generates a digital pulse train with pulses corresponding to peaks in the incoming signal. The digital pulse train is applied to a code breaker where the code is analyzed and a further code is generated anticipating the arrival of further pulses in order to verify the code. That further code is applied to a time gate generator which generate a code, synchronized with the incoming signal, that controls the high voltage of a gated image intensifier which is coupled to a video camera. Gating of the image intensifier is synchronized, as a result, with coded emissions from the source so that a video image from the camera can be displayed on a monitor and more easily differentiated from the background. The width of pulses generated by the time gate generator, the video camera, gain of the gated image intensifier, gain of the gated image intensifier and an auto-iris zoom lens coupled to the image intensifier are all under the control of a video processor.

Many research laboratories and manufacturers around the world are presently involved in the development of laser warning receivers (LWR) for the purpose of protecting military platforms against laser guided weapons by detecting, identifying and locating the laser sources associated with those weapons. A high angular resolution in the determination of the angle of arrival of the laser radiation from laser guided weapons is essential in order to effectively optimize counter measures deployment against those weapons. This type of resolution is only possible with the receivers available at present for powerful laser sources like laser range finders (LRF) and laser target designators (LTD) which generate relatively high levels of power density. The detection of low level power sources is still characterized by a very low resolution with none of the existing LWR's being capable of detecting radiation from a LBR with an angular resolution better than a quadrant. LBR detection up to now has been usually carried out by dedicated wide field-of-view (FOV) high-gain modules, one per quadrant, which simply detect a LBR source without any resolution.

Very high angular resolution laser beam rider detector having a gated image intensifier and a video camera

Her Majesty the Queen as represented by the Minister of National Defence of Her Majesty's Canadian Government


A polishing apparatus has a polishing tape (21), a supply reel (22) for supplying the polishing tape (21) to a contact portion (30) at which the polishing tape (21) is brought into contact with a notch portion (11) of a substrate (10), and a take-up reel (23) for winding up the polishing tape (21) from the contact portion (30). The polishing apparatus also has a first guide portion (24) having as guide surface (241) for supplying the polishing tape (21) directly to the contact portion (30), and a second guide portion (25) having a guide surface for supplying the polishing tape (21) tot the take-up reel (23). The guide surface (241) of the first guide portion (24) and/or the guide surface of the second guide portion (25) has a shape corresponding to a shape of the notch portion (11) of the substrate (10).

Heretofore, a polishing tape having abrasive particles has been employed to polish a notch portion formed in a semiconductor wafer. Specifically, a polishing tape is brought into contact with a notch portion of a semiconductor wafer and moved in a direction perpendicular to a surface of the wafer to polish the notch portion of the wafer.
In this conventional method, a polishing tape is deformed along a notch portion of a wafer under a polishing load. Edge portions of the polishing tape may scratch the notch portion of the wafer according to polishing conditions. Accordingly, a wafer may be flawed or unevenly polished at the notch portion according to polishing conditions. Further, if the polishing tape is insufficiently deformed, an area of the polishing tape contacting the wafer is reduced so that it is difficult to conduct stable polishing. In this case, it is difficult to achieve uniform polishing. Additionally, it is uneconomic in that the entire surface of the polishing tape is not used for polishing. Further, if an area of the polishing tape contacting the wafer is small when a curved surface is polished, the wafer needs to be divided into several small areas, which are sequentially polished. Accordingly, it takes much time to complete the polishing process.
Thus, if polishing conditions are improperly set when the notch portion of the wafer is polished, there arise problems such as scratches on the wafer by the edge portions of the polishing tape or unevenly polishing. In order to overcome such problems, a polishing tape may be thinned so as to accord with a shape of the notch portion. However, when a polishing tape is thinned, resistance to tension is reduced. Thus, the polishing tape has a limitation of the thinness.

Polishing apparatus and polishing method


A tag of an apparatus for simultaneously identifying massive tags according to the present invention may include an analog circuit unit to communicate with a reader through an analog signal and to receive energy via magnetic coupling with the reader. Further, the tag may include a digital circuit unit to be supplied with power from the analog circuit unit. The digital circuit unit may support a sleep mode for the tag to stand by in a low power state after transmitting an identifier (ID) to the reader and a wait mode for controlling random access to the reader.

1. Field of the Invention
The present invention relates to a passive radio-frequency identification (RFID) system using a high-frequency (HF) band, particularly 13.56 megahertz (MHz), and more particularly, to a system and an apparatus for simultaneously identifying stacked RFID tags and massive RFID tags using an HF band.
2. Description of the Related Art
A passive radio-frequency identification (RFID) system using a high frequency band, particularly 13.56 MHz, includes a tag having object information and a reader.
The tag of the passive RFID system using the HF band receives a carrier wave from the reader via magnetic coupling in a radio environment.
The tag is powered through the received carrier wave and communicates with the reader via load modulation.
Applications of RFID continue to expand from pellet or box level identification to individual item level identification. Recently, ISO/IEC 18000-3 Mode 3 (hereinafter, defined as an HF Gen2 international standard), in which an ultrahigh frequency (UHF) high-performance Gen2 protocol standard is applied to an HF band suitable for metal and liquids, has established.
A conventional amplitude-shift keying (ASK) HF international standard mainly performs one-to-one reader-tag communications. Thus, application of a conventional RFID system is limited to, for example, identification of a small number of tags.
In addition, the conventional technology involves a slow identification speed and limitations in tag identification performance due to an envelope detection method. Thus, in order to overcome theses technical problems, the present invention discloses an HF RFID apparatus and method for simultaneously identifying a plurality of stacked tags at a high speed in accordance with the recent HF Gen2 international standard.

System for simultaneously identifying massive RFID tags using HF band

ELECTRONICS AND TELECOMMUNICATIONS RESEARCH INSTITUTE


A target object has an upper surface including a first surface and a second surface located below the first surface. A method of focusing an optical system includes: measuring a surface position of the first surface; measuring a surface position of the second surface; obtaining, based on a measurement results of the surface position of the first surface, an in-focus condition in which the optical system is focused on the first surface; obtaining information about a step amount between the first surface and the second surface based on the measurement results of the surface positions of the first surface and the second surface; and focusing the optical system on the second surface based on the in-focus condition and the information about the step amount.

Field of the Invention
The present invention relates to a focusing method, focusing apparatus, exposure apparatus, and device manufacturing method.
Description of the Related Art
A microdevice such as a semiconductor device or liquid crystal display device is manufactured by a photolithography method of transferring, onto a photosensitive substrate, a pattern formed on a mask. An exposure apparatus used in the photolithography process includes a mask stage which supports a mask, and a substrate stage which supports a substrate. While sequentially moving the mask stage and substrate stage, the exposure apparatus projects and transfers, onto a substrate via a projection optical system, a pattern formed on a mask. In the exposure apparatus, every time each exposure target region (shot region) on a substrate is moved to an exposure position below the projection optical system by the substrate stage, a surface position measurement device detects a shift between the focus of the projection optical system and the surface position of the substrate to correct the surface position of the substrate and focus on it.
Japanese Patent Laid-Open No. 4-354320 discloses an oblique incidence surface position measurement device which detects a surface position by irradiating a surface to be detected with a beam from an oblique direction at an angle almost parallel to the surface. The oblique incidence surface position measurement device includes a light projecting unit which is arranged on one side with respect to a projection optical system and emits a beam, and a light receiving unit which is arranged on the other side and receives reflected light of the beam reflected by the surface to be detected. The purpose of irradiation with a beam at an angle almost parallel to the surface to be detected is to accurately focus the projection optical system on the substrate surface by using only light reflected by the surface of a photoresist (photosensitive agent) applied on the substrate. If the angle with respect to the surface to be detected is large, the irradiation light is refracted, enters the photoresist, reaches an underlying oxide film layer or a layer below it, and is reflected by the layer. As a result, a surface of the substrate that is being measured becomes unclear.
When the oblique incidence surface position measurement device is used, a high-accuracy detection result can be obtained without the influence of the projection optical system, compared to, for example, a TTL (Through The Lens) surface position measurement device via the projection optical system. In the projection optical system, aberration is satisfactorily corrected for only the wavelength of exposure light. Thus, when detection light is different in wavelength from exposure light in the TTL surface position measurement device, aberrations occur. In contrast, when surface position detection light is equal in wavelength to exposure light, the photoresist applied on the substrate is undesirably exposed to light. To avoid this, an exposure apparatus for manufacturing a microdevice often employs the oblique incidence surface position measurement device.
When manufacturing a microdevice such as a MEMS, a structure is sometimes formed on a substrate having an uneven shape. When exposing the bottom of the recessed portion of the substrate in order to form a structure in the recessed portion of the substrate, if the projection optical system is focused on the bottom of the recessed portion serving as the exposure target region, detection light may be reflected by the projecting portion in the oblique incidence surface position measurement device. In this case, detection light passing through the exposure target region cannot be obtained, and the oblique incidence surface position measurement device may not be able to focus on the exposure target region. Also, when the projecting portion exists at the periphery of the exposure target region, the oblique incidence surface position measurement device may not be able to focus on the exposure target region owing to the presence of the projecting portion.

Focusing method, focusing apparatus, exposure method, and device manufacturing method


A structured abrasive article comprises a backing with a topographically structured abrasive layer secured thereto. The topographically structured abrasive layer comprises precisely-shaped abrasive composites. A solid overlayer comprising eroding particles with a Mohs scale hardness of at least 4 and a water-soluble polymer is disposed on at least a portion of the topographically structured abrasive layer. Methods of making and using the structured abrasive articles are also disclosed.

For years, a class of abrasive articles known generically as "structured abrasive articles" has been sold commercially for use in surface finishing. Structured abrasive articles have a topographically structured abrasive layer affixed to a backing, and are often used in conjunction with a liquid such as, for example, water, optionally containing surfactant. The topographically structured abrasive layer has a plurality of shaped abrasive composites (typically having minute size), each having abrasive particles dispersed a binder. In many cases, the shaped abrasive composites are precisely-shaped, for example, according to various geometric shapes (e.g., pyramids). Examples of such structured abrasive articles include those marketed under the trade designation "TRIZACT" by 3M Company, St. Paul, Minn., and which are used in the automotive industry to remove defects in automotive clear coats (e.g., as available under the trade designation "466LA-3M TRIZACT FINESSE-IT FILM") based on urethane, acrylate, or silicate based chemistries.
Structured abrasive articles are often used in combination with a backup pad mounted to a tool (e.g., a disk sander or a random orbit sander). In such applications, structured abrasive articles typically have an attachment interface layer (e.g., a hooked film, looped fabric, or adhesive) that affixes them to the back up pad during use.
Many structured abrasive articles are known to lack aggressive cut upon initial use, with improvements in cut seen with continued use. This can occur because the abrasive particles are buried in the binder within the body of the abrasive composite and are not available for abrading. One technique used in the art for addressing the problem of lower initial cut has been to abrade the abrasive surface of the structured abrasive article, prior to its initial use, using another coated abrasive article such as sandpaper.
The cut performance of current products is very sensitive to the type of workpiece coating materials, which may be based on various kinds of technologies such as polyurethane, acrylate, powder coatings, or even silicate based hard coatings reinforced with nanoparticles.

Structured abrasive with overlayer, and method of making and using the same


A surround speaker system implements the speaker of a dipolar acoustic radiation characteristic by being installed in an upper part of a speaker stand, or it implements a surround speaker of a monopolar acoustic radiation characteristic by being installed at a lower central part of the speaker stand. The speaker stand is capable of controlling the speaker's height.

1. Field of the Invention
This invention relates to a speaker system for a theatrical home sound system, THX and Dolby AC-3, and, more specifically, to a surround speaker satisfying two different kinds of sound systems; one is the THX which is a surround speaker having a dipolar acoustic radiation characteristic, and the other is Dolby AC-3 which is a surround speaker of a monopolar acoustic radiation characteristic.
2. Description of the Related Art
FIG. 1 illustrates the construction of a THX system having a feature of a dipolar acoustic radiation characteristic. FIG. 2 illustrates the construction of a Dolby AC-3 system of a monopolar acoustic radiation characteristic. Conventionally, as the surround speaker systems which are typical home theater sound systems, the THX and Dolby AC-3 systems commonly have three front speakers; that is, a left front speaker 1, a right front speaker 2, a center speaker 3, and a sub-woofer 4. However, they have different surround speaker forms as follows.
While the THX system basically has the surround speakers 5 and 6 having a left and right dipolar acoustic radiation characteristic, the Dolby AC-3 system has the general left and right surround speakers 8 and 9 thereby providing a monopolar acoustic radiation characteristic. The THX surround speaker is preferably set up at a height of 1.5 to 3 m, but the Dolby AC-3 surround speaker is preferably set up at a height of 60 to 80 cm like a general speaker. In FIGS. 1 and 2, the reference numeral 7 indicates a screen.
Since the surround speaker 5,6 of the THX system is placed at the side of an audience and radiates sound bilaterally, the audience hears indirect sound rather than direct sound. Alternately, the surround speaker 8,9 of the Dolby AC-3 system allows the audience to possibly hear the direct sound.
However, the conventional surround speakers of a THX surround system and Dolby AC-3 system have a problem in their interchangeability. While the front speakers have nothing to do with this problem, the surround speakers involve such a problem because they are different from each other. For example, the surround effect becomes unnatural in the case where a sound medium in which recording is performed by the Dolby AC-3 method is reproduced through the speaker of a THX sound system. To solve the above problem, both THX and Dolby AC-3 surround speakers should be used, or alternatively only the medium for one method should be used.


The present invention can save space. A rubber extrusion device (1) containing a rubber extruder (2) for kneading rubber and extruding same from a discharge port (7), and a gear pump (3) connected to the discharge port (7) of the rubber extruder (2). The rubber extruder (2) has a cylinder part (4), which houses a rubber extrusion screw (5), above the floor surface on which the rubber extruder (2) is placed. The gear pump (3) contains an electric motor (8), a decelerator (9) linked to the electric motor (8), and a gear pump main body (10) linked to the decelerator (9). A pair of gears (11) which meshes with one another is installed in the gear pump main body (10). The electric motor (8) and the decelerator (9) are disposed in a space below the gear pump main body (10) or the cylinder part (4). Moreover, the output shaft (9b) of the decelerator and one of the gears (11) are linked by means of a wrapping transmission means.

Recently, as shown in FIG. 6(a), a method for producing a pneumatic tire where an unvulcanized ribbon-like rubber strip (a) is wound on an outer surface of a rigid core to form a green tire has been proposed. The rigid core has a shape similar an inner cavity of the pneumatic tire to be manufactured. In order to extrude the rubber strip (a), a rubber extrusion device (b) as shown in FIG. 6(b) has been proposed.
The rubber extrusion device (b) includes a rubber extruder (c) and a gear pump (d), for instance. The rubber extruder (c) is configured to have a screw shaft for kneading unvulcanized rubber and ext riling the same. The gear pump (d) is configured to include a gear pump main body (h) that comprises an electric motor (f), a reduce (g) linked to the electric motor (f), and a pair of gears. The gear pump (d) receives extruded rubber from the rubber extruder and then may quantitatively discharge it. The gear pump (d) includes an outlet port (e) for discharging a preliminary rubber strip. To form rubber strip (b), the preliminary rubber strip may further be pressed between a pair of calendar rolls.
Unfortunately, since the conventional rubber extrusion device (b) includes three parallel axes, i.e. a rotating shaft of the electric motor (f), an output shaft of the reducer (g), and rotating axes of gears, the electric motor (f) and the reducer (g) have to be arranged laterally outside the gear pump rain body (h). Thus, to install the rubber extrusion device on the floor, a large plane space is necessary. In particular, as shown in FIG. 7, when two rubber extrusion devices (b) are arranged in parallel one another, there is a problem that further larger space is necessary. The relevant a prior arts are as follows.


An optical connector includes a base member having a first hollow bore extending from a first end toward a second end, and a recess coaxially aligned with the first hollow bore. The recess has a first internal perimeter and a second internal perimeter. The first perimeter is smaller than said second perimeter. The base member can have a post extending up from a bottom of the recess. The first hollow bore passes through the past and terminates at an end of the post. The post can have an end that terminates substantially in alignment with at least a portion of a termination region disposed between the first internal perimeter and the second internal perimeter.

1. The Field of the Invention
The present invention relates to optical connectors, and more particularly to ferrule-type plug/receptacle optical connectors.
2. The Relevant Technology
Ferrule-type plug/receptacle optical connectors are well known in the art. These connectors are typically used to position two optical waveguides, such as optical fibers, so that light can propagate between the two waveguides or between the optical waveguide and an optical component or subassembly. The optical connectors can be repeatedly removed and reconnected to each other while providing an optical alignment therebetween to minimize connection losses.
A common ferrule-type optical connector, designated generally as reference numeral 100, is illustrated in FIGS. 1A and 1B. As shown in FIG. 1B, connector 100 includes a base 102 that receives a ferrule 104. The base 102 includes a central bore 106 that extends from a first end 108 toward a second end 124 having an annular alignment recess 109 formed therein. The recess 109 is centered about bore 106. The recess 109 includes a bottom wall 112 and a sidewall 114. A post member 110 extends from bottom wall 112 and towards a center of recess 109, with bore 106 running through post member 110. The sidewall 114 of recess 109 has a height above bottom wall 112 that is greater than that of post member 110. A retention channel 116 is formed in a lateral outer surface of base 102 that acts as the mating structure to receive a portion of the housing/shell (not shown) of the transceiver module that contains the receiver optical sub-assembly (ROSA) and transmitter optical sub-assembly (TOSA) (not shown).
The ferrule 104 received by base 102 has a generally cylindrical shape, with an annular outer sidewall 118 and a mating surface 120 on an end 126. A central bore 122 runs through ferrule 104. The ferrule 104 inserts into recess 109 of base 102 until ferrule mating surface 120 engages with recess bottom surface 112, as is shown in FIG. 1A. The outer diameter of ferrule sidewall 118 is slightly larger than an inner diameter of recess sidewall 114, so that there is an interference fit therebetween. This interference fit ensures that ferrule 104 is correctly positioned both laterally and axially when mating surface 120 engages bottom surface 112. The combination of the mating surfaces and the interference fit between base 102 and ferrule 104 ensures that the bores 106/122 (and therefore optical elements and waveguides disposed therein) are precisely aligned with each other.
One problem that has been discovered is that many times the lateral forces of the interference fit between base 102 and ferrule 104 causes deformation of ferrule 104. This deformation results in bore 122 actually curving inwardly opposite the contact area between sidewall surfaces 114/118. This curvature can interfere with the waveguide and/or other optical components mounted in bore 122. It can also prevent these components from being properly positioned relative to bore 106 of base 102 and any optical elements therein.
One solution can be to reduce the lateral forces of, or completely eliminate, the interference fit between ferrule 104 and base 102. However, any free space between sidewall surfaces 114/118 allows lateral movement between base 102 and ferrule 104 that misaligns bores 106/122. This can cause misalignment of the optical components with associated degradation of alignment and optical coupling.

Counterbore base member for ferrule-type optical connector


A motor system and method providing improved power factor and harmonic control of power supplied to a motor. The system and method employs a power conversion circuit connected to an AC voltage source for supplying power to a power supply link of the motor. The power conversion circuit includes a rectifier circuit and a power factor correction circuit. The rectifier circuit rectifies the AC voltage and has first and second outputs corresponding to upper and lower rails of the power supply link, respectively. The power factor correction circuit is connected directly between the first output of the rectifier circuit and a node of the corresponding upper rail of the power supply link for improving the power factor of the power supplied to the motor.

This invention relates generally to motor systems and, particularly, to a power conversion circuit for an electronically controlled motor providing passive power factor correction and harmonic control.
Presently available power supply circuits provide a DC voltage, rectified from an AC source, for powering loads such as a voltage source inverter drive for a brushless DC motor. Typically, a diode bridge rectifier rectifies the AC source voltage and a DC link capacitor provides energy storage for reducing ripple in the rectified voltage. The load, connected across the DC link, is a single or multi-phase electronically commutated motor powered by an inverter bridge, for example.
The power supply circuits known in the art are deficient for several reasons. A soft or hard switching converter may be used, rather than a passive circuit, for improving power factor but such a converter has switching losses associated with it. Other conventional power supply circuits provide power factor correction but do not reduce the level of harmonics in the input current to an acceptable level. In addition, presently available power factor correction circuits for use with a power supply are not easily retrofitted or installed in the DC link of an existing motor.
In general, brushless DC motors are disclosed in, for example, U.S. Pat. Nos. 5,592,058, 5,506,487, 5,491,978, 5,465,019, 5,423,192, 4,933,584 and 4,757,241, all of which are commonly assigned with the present invention described herein and the entire disclosures of which are incorporated herein by reference.


A cathode material capable of improving capacity and superior low temperature characteristics, and a battery using the cathode material are provided. A cathode and an anode are layered with an electrolyte layer and a separator in between. The cathode contains a complex oxide containing lithium, manganese, nickel, and cobalt; a complex oxide containing lithium and at least one of nickel and cobalt; and a complex oxide containing lithium and manganese and having a spinel structure or a phosphorus oxide containing lithium and iron at a given ratio.

1. Field of the Invention
The present invention relates to a cathode material in which a plurality of cathode active materials are mixed and a battery using the cathode material.
2. Description of the Related Art
In recent years, portable electronic devices such as a notebook personal computer, a combination camera (videotape recorder), and a mobile phone have been introduced one after another, and their size and weight have been reduced. Accordingly, secondary batteries as a portable power source have been highlighted, and active researches for obtaining a higher energy density have been implemented. Under such circumstances, as a secondary battery having a high energy density, lithium ion secondary batteries have been in practical use.
In such lithium ion secondary batteries, for example, it is proposed that in order to improve the battery characteristics such as a capacity and cycle characteristics, as a cathode active material, two kinds of complex oxides containing lithium (Li), manganese (Mn), nickel (Ni) or cobalt (Co) and the like are mixed (for example, refer to Japanese Unexamined Patent Application Publication No. 2003-173776).


An electrochromic device includes a stack successively including: a first current collector, an electrochromic electrode made of a material capable of reversibly inserting metal ions, an electrolyte, a second current collector, a reflective substrate contacting the first current collector or with the second current collector. It includes a single electrochromic electrode and has at least the two following functional states: a first absorbing functional state, induced by the application of a first electric voltage between the two current collectors, wherein the device includes metal ions reversibly inserted into the material of the electrochromic electrode; and a second reflective functional state subsequent to the application of a second electric voltage between the two current collectors, wherein a metal layer is formed between the electrolyte and the second current collector, this metal layer including at least part of the metal ions initially reversibly inserted into the material of the electrochromic electrode.

A conventional electrochromic device enables to modify the optical transmittance, reflectance, or absorbance properties of an electromagnetic radiation. Such a modulation is obtained by means of an active electrochromic electrode, which allows a reversible change of optical state when an electric voltage is applied across the electrochromic device.
This type of device comprises a stack formed of the following elements:
a first current collector;
a first electrochromic electrode;
an electrolyte;
a second electrochromic electrode;
a second current collector; and
a support.
The current collectors are used as terminals enabling to connect the device to an external electric voltage source.
Further, at least one of the electrodes is optically active. It enables to modulate the optical properties of an electromagnetic radiation by passing from a colored state to a transparent state. Such a change of optical state results from the insertion or from the deinsertion of ions into or from the material forming the electrochromic electrode when an electric voltage is applied across the device.
The second electrode may also be optically active, but with a reverse ion flow, or passive, that is, transparent whatever the ion flow. It is necessary in known structures to provide the storage of metal ions which migrate from the first electrochromic electrode.
The electrolyte is an electronic insulator but an ion conductor. It enables to ensure the ion migration between the two electrodes.
The performance of an electrochromic device especially depends on the contrast, that is, on the difference between the maximum and the minimum optical response of the device. A high-performance device generally has a high contrast.
Even though prior art devices generally enable to obtain a satisfactory contrast, they undergo optical losses due to the absorption of the materials used and to the reflection phenomenon at the level of the substrate/current collector/electrochromic electrode/electrolyte/electrochromic electrode/current collector interfaces.
A solution enabling to limit optical losses, and thus to obtain a better contrast, comprises placing the active electrochromic electrode at the front surface of the device, that is, in direct contact with the electromagnetic radiation.
However, since the number of optical interfaces remains unchanged, such devices do not do away with optical losses induced by the interfaces. Further, such devices may also raise problems of cyclability in time as the cation insertion/deinsertion cycles are repeated. Document U.S. Pat. No. 7,042,615 describes a device of this type.
The present disclosure relates to an electrochromic device enabling to solve these technical problems, and especially to improve the contrast by decreasing optical losses.

COMMISSARIAT A L'ENERGIE ATOMIQUE ET AUX ENERGIES ALTERNATIVES


An offset transistor and a non-offset transistor each including an oxide semiconductor are formed over one substrate. An oxide semiconductor layer, a gate insulator, and first layer wirings which serve as gate wirings are formed. After that, the offset transistor is covered with a resist and impurities are mixed into the oxide semiconductor layer, so that an n-type oxide semiconductor region is formed. Then, second layer wirings are formed. Through the above steps, the offset transistor and the non-offset transistor (e.g., aligned transistor) can be formed.

1. Field of the Invention
The present invention relates to a semiconductor including an oxide semiconductor. Note that here, semiconductor devices refer to general elements and devices which function utilizing semiconductor characteristics. For example, a memory, an arithmetic circuit, a rectifier, a display device, and the like which include a semiconductor can be given as semiconductor devices; however, the present invention is not limited thereto. For example, Patent Document 1 can be referred to for a memory including a semiconductor.
2. Description of the Related Art
In recent years, a transistor, a display device, a memory, and the like manufactured using a composite oxide of indium, gallium, and zinc have been reported (for example, see Patent Documents 2 to 5).

Semiconductor device and manufacturing method thereof

Semiconductor Energy Laboratory Co., Ltd.


This invention provides a series of recombinant Thermoanaerobacterium saccharolyticum glucose isomerases with improved catalytic activity and thermostability obtained by using recombinant techniques. These recombinant glucose isomerases comprise amino acid variation including phenylalanine (Phe) at position 139, alanine (Ala) at position 182, serine (Ser) at position 187, and glutamine (Gin) at position 299, and carry at least one additional mutated amino acid at position 87, position 217, position 260 or position 276, and possess a higher catalytic activity than that of the wild-type when using D-glucose as substrate. These recombinant glucose isomerases can be used for direct production of high fructose corn syrup containing 55% [wt] or higher concentration of fructose.

Glucose isomerase (E.C.188.8.131.52, or xylose isomerase) is a key enzyme in the pentose phosphate pathway. It is one of the most important industrial enzymes (Kaneko et al., Bioscience, Biotechnology, and Biochemistry 2000, 64:940-947). In the food industry, it is used for the manufacture of high fructose corn syrup.
The equilibrium of the isomerization of D-glucose to fructose is primarily dictated by the temperature of the reaction. The higher the temperature, the more the fructose in the final reaction mixture. At present, the commercial glucose isomerases come mainly from Actinoplanes missouriensis, Bacillus coagulans or Streptomyces species, and are not stable at high temperature (e.g. temperature above 65° C.). Consequently, the current commercial isomerization is restricted to operate at around 60° C. and the products normally contain no more than 44% of fructose. The high fructose corn syrup containing higher fructose is therefore generated using expensive chromatographic enrichment, leading to higher production cost.
Scientists around the world have been working on the identification of thermostable and highly active glucose isomerases from thermophilic bacteria, and production of the same via protein engineering. J. G. Zeikus and his collaborators isolated and studied thermostable glucose isomerases from thermophilic bacteria, such as Thermoanaerobacterium saccharolyticum (hereinafter referred to as T. saccharolyticum) and Thermotoga neapolitana (Lee et al., Journal of General Microbiology, 139:1227-1234, 1993; Vieille et al., Methods in Enzymology, 330:215-24, 2001; Lee et al., Journal of General Microbiology, 139:1241-1243, 1993; Scriprapundh et al., Protein Engineering, 13:259-265, 2000; Scriprapundh et al., Protein Engineering, 16:683-690, 2003; Zeikus et al., U.S. Pat. No. 5,656,497). Nevertheless, the thermostabilities of the thermostable glucose isomerases from these or other bio-resources are still much to be desired, as the activities of thereof are low, and thus are not applicable to industrial applications. Therefore, glucose isomerase with high activity, or high activity and thermostability remains desirable.

Isolated DNA encoding recombinant glucose isomerase


A motor-pump unit, for providing pressure for a brake actuating device having a pneumatic brake booster including a pump and an electric motor driving the pump, the pump being a dual diaphragm pump having two opposed working diaphragms, each of which is clamped between a pump casing and a working chamber cover and delimits a working chamber, and moveable by a crank drive having connecting rods and bearings, the working diaphragm connected firmly to a tappet and, together with the connecting rod, in each case forming a diaphragm unit. In order to provide a low-noise motor-pump unit which is more cost-effective and requires reduced expenditure on assembly, the connecting rods are made of plastic, wherein in each case one tappet and one bearing are encapsulated with the material of the connecting rod. Alternatively, the connecting rods can be formed in one piece with the tappet and provided as sintered components.

In order to provide vacuum for a pneumatic brake booster, the interior of which is subdivided into at least one vacuum chamber and a working chamber, use is made of vacuum pumps which suck residual air out of the vacuum chamber and expel it into the atmosphere. In the automobile industry, vane-cell pumps or swing-vane pumps are normally used for this purpose. As a result of their principle, these exhibit a great deal of friction and have to be lubricated in order to achieve an acceptable service life. Vacuum pumps with vanes driven by the internal combustion engine of the motor vehicle are therefore connected to the oil circuit of the internal combustion engine. Nevertheless, a noticeable proportion of the power output by the internal combustion engine has to be expended to drive such a pump. This is the case even when the vacuum in the chamber to be evacuated has already been built up completely. It is therefore expedient to operate the vacuum pump with electrical energy and to switch it on only when the absolute pressure in the vacuum chamber rises above a predetermined value.
Furthermore, in vehicles with electric or hybrid drive, the vacuum pump cannot be driven by the internal combustion engine or cannot be driven from time to time. Therefore, electrically driven vacuum pumps are used in these vehicles.
Equipping such an electrically driven pump with a lubricant circuit or connecting one to such a circuit would mean a disproportionately high expenditure. Thus, for use in motor vehicles having brake systems with electrically driven vacuum pump, only dry-running vacuum pumps are suitable. In vane-cell pumps, the self-lubricating material graphite is used for this purpose, from which the vanes are produced with the necessary precision with a great deal of effort. Therefore, efforts are directed at using a diaphragm pump for the electrical provision of braking vacuum.
A generic mode-pump unit is known, for example, from DE 10 2007 005 223 A1, which is incorporated by reference. The known motor-pump unit has a diaphragm unit with a working diaphragm which is firmly connected to a tappet. The tappet is in turn fixed to a connecting rod by welding or screwing.


An attribute of image data can accurately be discriminated. An image attribute discrimination apparatus includes a heterogeneous region extracting unit that specifies a heterogeneous region from image data. The heterogeneous region includes a heterogeneous matter whose attribute is different from that of a content originally produced by the image data. An image attribute discrimination apparatus further includes a scene discrimination unit that discriminates the attribute of the image data based on a feature quantity extracted from a pixel group except each pixel in the heterogeneous region in each pixel of the image data.

1. Technical Field
One or more embodiments of the present invention relate to image attribute discrimination processing of discriminating an attribute of digital-format image data such as a still image and a moving image, particularly to an image attribute discrimination apparatus, an attribute discrimination support apparatus, an image attribute discrimination method, an attribute discrimination support apparatus controlling method, and a control program for improving accuracy of the image attribute discrimination processing.
2. Related Art
Recently, there is conducted research and development of a technique of analyzing a feature of image data to automatically discriminate an attribute of the image data. Specifically, a feature quantity is extracted from a pixel value possessed by any piece of image data such as the still image or moving image which is imaged with a digital camera, a digital video camera, or a camera-equipped mobile phone, the still image captured by a scanner, and the moving image or capture image which is recorded by a DVD recorder, and a scene (attribute) expressed by the image data is discriminated. For example, what kind of scene (such as person, landscape, night view, sunset, firework, room interior, snow, beach, flower, cooking, and business card and document) taken by the real-time image data processed by the digital camera is discriminated, which allows a photograph to be taken while a photographing mode of the digital camera is set to an optimum state according to the scene.
For example, Japanese Unexamined Patent Publication Nos. 11-298736 (published on Oct. 29, 1999), 2002-218480 (published on Aug. 2, 2002), 2005-310123 (published on Nov. 4, 2005), and 2005-122720 (published on May 12, 2005) disclose known image attribute discrimination processing techniques. In the techniques disclosed in Japanese Unexamined Patent Publication Nos. 11-298736, 2002-218480, 2005-310123, and 2005-122720, the feature quantity is extracted from target digital image data to perform processing of checking the feature quantity against a previously-prepared model feature quantity with respect to a specific scene, and a scene is discriminated based on a degree of coincidence with the feature quantity of the specific scene.
More specifically, in an image processing apparatus disclosed in Japanese Unexamined Patent Publication No. 11-298736, a determination whether the image data is the sunset scene is made using a histogram of hue data, and a determination whether the image data needs to be corrected is made based on the determination whether the image data is the sunset scene. The image processing apparatus makes the histograms of a value a product of the hue and chroma and a value of a product of the hue and lightness with respect to the pixels belonging to a range of red to yellow in the pixels constituting the target image data, and the image processing apparatus determines that a variance of the histogram that is larger than a specific reference is the image of the scene "sunset".
Japanese Unexamined Patent Publication No. 2002-218480 discloses an image photographing apparatus that discriminates a plurality of scenes such as "portrait", "sunset", and "night view" with respect to the target image data with information on the presence or absence of a person and information on a color histogram as a common feature index.
Japanese Unexamined Patent Publication No. 2005-310123 discloses an apparatus that accurately selects various images of specific scenes with respect to a feature portion corresponding to the specific scene in consideration of tendency of disposition in the image and in consideration of a position of photographing frame and a variation of area ratio by a photographing frame taking difference.
In an apparatus disclosed in Japanese Unexamined Patent Publication No. 2005-122720, reference data in which a kind of the feature quantity and an identifying condition are defined is prepared in each of the plurality of scenes designated as the specific scene in order to identify the scene, and scene discrimination is accurately performed by referring to the identifying condition.
However, in the conventional configurations, unfortunately the attribute cannot correctly be discriminated when a substance, a shadow, and a shape which are different from those of the original attribute of the image data (hereinafter referred to as a heterogeneous matter) are included in the image data that becomes the attribute discrimination target. That is, the feature obtained from a pixel group (hereinafter referred to as a heterogeneous region) taking the heterogeneous matter is different from the feature of the original attribute. Therefore, when the feature quantity of the whole image data is extracted while the feature quantity of the heterogeneous region is mixed in the feature quantity of the image data, the checking against the model feature quantity is not successfully performed, which results in false scene discrimination is performed to the image data or scene discrimination is performed with low likelihood.
For example, the generation of the heterogeneous region in the image data is attributed to objects, (also includes telop in the case of the moving image) such as a character, an illustration, a graphic, a stamp, and a graffiti, which are added to the image data that becomes the attribute discrimination target using an image edit tool in an image edit process. Additionally, sometimes an unintended phenomenon (such as a white spot phenomenon such as smear) emerges in the image data photographing process depending on a photographing environment or a subject state or an intended body such as a finger shadow is taken in the photograph. Additionally, sometimes an original plate or a backside color of an original is taken in a lack portion of the original in the process of scanning the origin such as the photograph (due to the broken original or folded original). The heterogeneous region is not limited to the above-described examples. The above problems are commonly generated irrespective of the condition, environment, and situation relating to the image data, when the attribute discrimination is performed to any piece of image data including the heterogeneous matter whose attribute is different from that of the original scene.

Image attribute discrimination apparatus, attribute discrimination support apparatus, image attribute discrimination method, attribute discrimination support apparatus controlling method, and control program


Slurry compositions for selectively polishing silicon nitride relative to silicon oxide, methods of polishing a silicon nitride layer and methods of manufacturing a semiconductor device using the same are provided. The slurry compositions include a first agent for reducing an oxide polishing rate, an abrasive particle and water, and the first agent includes poly(acrylic acid). The slurry composition may have a high polishing selectivity of silicon nitride relative to silicon oxide to be employed in selectively polishing a silicon nitride layer in a semiconductor manufacturing process.

1. Technical Field
Exemplary embodiments of the present invention relate to slurry compositions for selectively polishing silicon nitride relative to silicon oxide, methods of polishing a silicon nitride layer and methods of manufacturing a semiconductor device using the same. Particularly, exemplary embodiments of the present invention relate to slurry compositions for selectively polishing silicon nitride relative to silicon oxide that may be employed in a semiconductor manufacturing process, methods of polishing a silicon nitride layer and methods of manufacturing a semiconductor device using the same
2. Description of the Related Art
A semiconductor manufacturing process generally includes forming a layer such as an insulation layer or a conductive layer on a substrate, planarizing a surface of the layer, etching the layer to form a pattern having a predetermined shape, or the like.
A process for planarizing a layer may be, for example, an etch-back process, a reflow process, a chemical mechanical polishing (CMP) process or the like. The CMP process is widely used for global planarization or for forming a highly integrated circuit device, as the global planarization may only be achieved by the CMP process and the CMP process has excellent planarization quality.
In the CMP process, a semiconductor wafer to be polished is mounted on a chuck, a slurry composition including an abrasive is provided between the semiconductor wafer and a polishing pad, and then the semiconductor wafer is rotated and pressed against the polishing pad so that the semiconductor wafer is planarized. The semiconductor wafer is mechanically polished by rubbing a surface of the semiconductor wafer with the abrasive and the polishing pad, and also chemically removed by a chemical reaction between chemical components of the slurry composition and the surface of the semiconductor wafer.
The polishing efficiency of the CMP process may be determined by the type of a CMP apparatus, components of the slurry composition, the type of the polishing pad and the like. Among several factors, the components of the slurry composition may have an influence on the polishing efficiency. With regard to the polishing efficiency, the slurry composition should be able to rapidly polish an object, and also should not be able to cause damage to several structures adjacent to the object to be polished.
Commercial slurry compositions have been mainly employed in polishing a silicon oxide layer using a silicon nitride layer as a polishing stop layer, because the slurry compositions exhibit a polishing rate of a silicon oxide layer substantially faster than the polishing rate of a silicon nitride layer. When such slurry compositions are used in polishing a silicon nitride layer, the polishing efficiency may decrease due to a low polishing rate of silicon nitride, and a silicon oxide layer which may be exposed during the polishing process can be unintentionally damaged. Additionally, the slurry compositions may not be expected to have a high quality of planarization and uniformity for a silicon nitride layer, and there also may be difficulty in determining a polishing stop point.


A one-way damper includes a cylindrical housing, a viscous fluid contained within the housing, a rotor rotatably disposed in the housing, and a valve body. The rotor has a center part for forming a rotational center, and a control wall extending radially outwardly from the center part for dividing an inside of the housing. The control wall has a distribution path. The valve body has a holding part for holding the center part, and a free edge part extending from one side of the holding part for opening-and closing the distribution path. A seal member prevents the viscous fluid from leaking between the housing and the rotor.

The present invention relates to a one-way damper, and in particular to a one-way damper that controls the rotation of a body in one direction, and electronic devices using this one-way damper.
A conventional one-way damper includes a cylinder shaped housing, viscous fluid within this housing, a center part which is a center of the rotation, a rotor which divides the inside of the housing by standing to the diameter direction from this center part and which has a control wall which forms a connecting path with respect to the housing, and in which the center part and the control wall are rotatably housed in the housing. The conventional one-way damper also includes a control valve, in which one side near the control wall is the rotation center, and the other side contacts the inner surface of the housing, and rotates with the rotor, and a seal member which prevents viscous fluid from leaking between the housing and the rotor is suggested (see Patent Document 1).
Patent Document 1: Japanese Patent No. 2882109
In the conventional one-way damper, the space between the housing, the rotor and the control valve forms an orifice. Because a rotation point of the control valve is free, the orifice at the time of operation is large. Accordingly, large damping torque cannot be obtained in a conventional one-way damper.
In view of the problems described above, an object of the present invention is to provide a one-way damper that can achieve a large damping torque and maintain a certain accuracy of the damping torque, and an electronic device that uses this one-way damper.
Further objects and advantages of the invention will be apparent from the following description of the invention.

One-way damper and electronic devices using the one-way damper


A method and system for re-fueling natural gas vehicles, at home, utilizing a hydraulic pressurization-chamber instead of a conventional mechanical compressor, to boost low-pressure gas (usually about 1 psi) up to the 3500-4000 psi required to re-fuel automotive equipment. This Residential Refueling Facility (RFF) will acquire natural gas from a residential public utility gas line into a flexible bladder located inside a steel high-pressure vessel where it will be pressurized by pumping a hydraulic fluid into the annulus between the outside of the bladder and the inside walls of the steel vessel. When the increased pressure reaches a level above the pressure existing in the on-board storage tanks on the vehicle being re-fueled, the gas in the bladder will be squeezed out to the on-board storage tank. The process is then repeated until the on-board storage tanks are filled.

The present invention is classified as a Residential Fueling Facility (RFF) by the National Fire Prevention Association (NFPA), and relates to a method and system of compressing natural gas at a residence to re-fuel natural gas vehicles. More particularly, it relates to such a method and system especially adapted to the economics of the equipment used to increase the pressure (to pressurize or compress) the gas from a residential gas supply line up to the 3500-4000 pounds per square inch (psi) required to re-fuel on-board storage tanks on natural gas vehicles. The present invention relates, specifically, to the use of a flexible bladder, inside a steel vessel, to receive, and temporarily-store, natural gas from a residential gas supply line. In order to increase the pressure of the temporarily-stored gas inside the bladder, a hydraulic fluid is pumped into the annulus between the outer walls of the bladder and the inner walls of the steel vessel. With continued pumping, the pressure of the hydraulic fluid will exceed the gas pressure inside the bladder and the bladder collapses in size which results in the gas inside the reduced-size container (the bladder) being elevated to a higher pressure. The higher-pressured gas can then be transferred to a compressed natural gas (CNG) storage tank on-board the vehicle being refueled. In the absence of an internal flexible bladder to pressurize the gas, a more-expensive mechanical compressor would have to be used, which would increase the cost to the residence-owner and make it more difficult to re-fuel automotive equipment at home.
The conventional manner of pressurizing (compressing) natural gas, at home, is to utilize commercially-available RRF units which utilize conventional mechanical compressors to boost the pressure of the gas up to the 3500-4000 psi level required to re-fuel on-board storage tanks in natural gas vehicles, which are so expensive as to make the use of CNG to re-fuel vehicles non-competitive with fuels such as gasoline and diesel to re-fuel automotive equipment.
The present invention is intended to solve the need for a more-economical method of pressurizing (compressing) natural gas from the low-pressure available at the standard household gas utility line of approximately 1 psi, which must be boosted up to the 3500-4000 psi level utilizing a multi-stage mechanical compressor. The desired economics are possible due to the elimination of the multi-stage compressor and to replace the compressor with a self-contained pressurization chamber composed of a steel cylinder, a flexible bladder inside the steel cylinder, and a hydraulic system (pump, prime-mover, surge tank) to pump a hydraulic fluid in the annulus between the bladder and the steel walls of the cylinder.
The flexible bladder is a one-piece cylinder-liner which, when filled with gas from the gas supply line, will inflate substantially to the interior walls of the steel cylinder, which will be sized to accommodate the volume of gas required to re-fill the on-board storage tanks of two natural gas vehicles in a slow-fill period (usually approximately 5 hours). The bladder is made of rubberized nylon, or if, by choice, some other member of the elastomer family of synthetic rubbers, compatible with natural gas, fresh water/anti-freeze mix, or mineral hydraulic oil, with one domed-end, the other end open and attached (bonded) to the face of a flange attached to the steel cylinder.
The hydraulic fluid is a matter of choice and can be either a water/anti-freeze mix, or a hydraulic mineral oil.
The present invention is particularly designed for more-economical at-home pressurization of natural gas for natural gas vehicles, utilizing a hydraulic pump instead of a mechanical compressor. While primarily designed for home use, the invention can also serve as a more-economical method of re-fueling natural gas vehicles while at work in business and commercial buildings; in commercial buildings to fuel fork-lift trucks; at airports to re-fuel airline baggage and passenger transports; and generally any other method of transportation involving gasoline/diesel fuels.

Method and system of hydraulically-pressurizing natural gas at a residence to re-fuel natural gas vehicles


An image pick-up apparatus comprises a filter whose transmitting wavelength band is changed depending on an input drive signal, a spectral control unit for inputting the drive signal to the filter, thereby changing the transmitting wavelength band of the filter in plural steps, a single image pick-up unit disposed at rear side of the filter, for obtaining image data every time the transmitting wavelength band of the filter is changed, and a record control unit for recording plural pieces of image data obtained by the image pick-up unit.

Conventional cameras are separated into two types, cameras of a single plate type and cameras of separate plate type. The camera of a single plate type uses a single image pick-up element disposed in two dimensions, such as CCD and CMOS image sensor. The image pick-up element with RGB filter and/or CMY filter provided thereon is used to shoot a color picture. These RGB filter and CMY filter are Bayer arranged color filters.
The camera of separate plate type uses plural image pick-up elements. In this type of camera, a spectral device disposed behind an image pick-up lens, such as a beam splitter, is used to disperse light from an object, and the dispersed RGB lights fall on these image pick-up elements through color filters, whereby R, G, D data are generated and combined into a color image.
However, either in the camera of a single plate type or in the camera of a separate plate type, since transmitting wavelengths are determined by the color filter characteristics in shooting operation, it is hard in principle to obtain spectral images for respective wavelength bands.
Further, the camera of a separate plate type has disadvantages that plural image pick-up elements are used and alignment of these pick-up elements requires fine adjustment.
The present invention has been made to solve the disadvantages involved in the conventional apparatuses, and has an object to provide an image pick-up apparatus, which is compact in size and can obtain a spectral image of each spectral band.

Image pick-up apparatus and method of controlling the image pick-up apparatus


MISFET's are formed in the depletion mode in advance. MISFET's which are selected from these depletion-mode MISFET's are then formed into enhancement-mode or weak depletion-mode MISFET's to thereby write desired data into the memory cells of a read-only memory. The change of the MISFET's from the depletion mode into the enhancement mode (or weak depletion mode) is effected by introducing an impurity into the channel regions of the selected MISFET's in a manufacturing step that is carried out after the formation of the gate electrodes of the MISFET's.

The present invention relates to a process for producing a semiconductor integrated circuit device. More particularly, the present invention pertains to a technique which may effectively be applied to writing of data into memory cells in a mask-programmed ROM (Read Only Memory).
In mask-programmed ROM's, each memory cell is generally formed using a MISFET, and writing of data into this memory cell is effected by controlling the threshold voltage of the MISFET.
As one type of such mask-programmed ROM, vertical ROM's are known (see, for example, the specification of Japanese Patent Laid-Open No. 30388/1977). In such a vertical ROM, memory cells which are constituted by MISFET's are provided at the intersections, respectively, between data and word lines. A plurality of such memory cells are connected in series to form a row of memory cells, and a plurality of such memory cell rows are arranged to form a memory cell array.


A digital memory circuit for electronic applications. The circuit has at least one memory element connected in series with a load resistor. The digital memory circuit also includes a voltage supply and a data output terminal. The memory element in the digital memory circuit is in the form of a silicon dioxide film derived from a hydrogen silsesquioxane resin. The silicon dioxide film is characterized by a jV curve which includes both resistive and conductive regions for the memory element.

This invention is directed to threshold switching devices which exhibit negative differential resistance (NDR), and to certain ceramic threshold switching devices which are useful as thin film memory devices.
Devices which exhibit threshold switching, and metal oxide devices which exhibit threshold switching with negative differential resistance (NDR) are known in the art. The switching and negative differential resistance (NDR) characteristics of silicon oxide films has also been described in the literature.
The use of thin film silica coatings derived from hydrogen silsesquioxane resin to provide protection and electrical insulation is not new, but the use of those coatings to form switching devices which are useful as thin film memory devices is believed to be novel.
Coatings and switching devices formed by depositing a thin hydrogen silsesquioxane derived silicon dioxide film between at least two electrodes and applying a voltage above a threshold voltage across the electrodes, are described in detail in a prior copending patent application U.S. Ser. No. 07/694721 filed May 2, 1991, and entitled "Threshold Switching Devices". The present invention involves these and similar devices and their utility in thin film memory applications.
Memory arrays containing thin film memory devices according to the present invention offer the advantage that information can be retained without a holding voltage, i.e. true non-volatile memory. Further, it is possible to employ simplified metallization patterns because there is only one active element plus one passive element which is the load resistor. In addition, simplified address and read/write line patterns can be used.
State of the art static random access memory (RAM) cell arrangements typically require a supply voltage connection for memory retention; two cross-coupled transistors for the storage of 0 and 1, and 1 and 0; two load resistors; two access transistors controlled by the same wordline; and two bit lines, one for 0 and the other for 1. In contrast, the static RAM cell of the present invention containing the hydrogen silsesquioxane resin-derived silica switching cell offers the benefits that no permanent power supply is required, and that there is no power dissipated in the memory cell. Further, only one storage cell and one load resistor are necessary. In addition, only one access transistor is needed for WORD SELECT; and only one bit line is necessary for BIT SELECT for writing with voltage pulse and for reading data.


A shaft seal includes a lip at the low pressure end with a tapered cylindrical body extending from the lip. The tapered cylindrical body has a first diameter where the tapered cylindrical body meets the lip and a second diameter at a distal end that is exposed to a high pressure fluid. An aperture is formed through the lip and through the tapered cylindrical body following an axis of the tapered cylindrical body. The aperture has a first end at the lip and a distal second end. At the first end, the aperture has a first inner diameter that is slightly greater than the outer diameter of the shaft at the distal end, the aperture tapers to a second inner diameter which is approximately the diameter of the shaft. An o-ring, is positioned around the tapered cylindrical body applying pressure on the tapered cylindrical body against the shaft.

Devices that mix and spray pressurized fluids such as paints and resins have progressed in the art. Certain materials need to be mixed just before application, for example, a resin and a catalyst. If mixed before application, depending upon the time lag between the mixing and the application steps, the mixed resin and catalyst may settle, providing an uneven application, or even worse, may begin to harden.
Resins have numerous uses including forming and coating boat hulls, spas/hot tubs, bath tubs, sinks, etc. A resin such as polyester is typically mixed with a catalyst such as methyl-ethyl-ketone peroxide and applied to a surface. Catalysts allow the resin to cure, otherwise, the resin would remain fluid and sticky.
Early spraying systems emitted resin from one nozzle and catalyst from a second nozzle, in theory, mixing the resin and catalyst in air and after contact with the target surface. Such devices effectively spray the resin and catalyst, but uniform mixing of the resin and catalyst is important for proper application to various surfaces.
U.S. Pat. No. 2,878,063 to Stephen P. Kish is an example showing a spray gun in which the catalyst and resin are mixed in a stream of air emanating from a trigger gun. This is an example of an external mix gun. In an external mix gun, the resin and catalyst are atomized separately and directed toward each other. The resin and catalyst combine in the air before contacting the target. As discussed previously, this often results in an incomplete mixing of resin and catalyst. When the catalyst is atomized separately from the resin, much of the atomized catalyst disperses into the atmosphere and in the work environment where the application is taking place. This causes safety concerns for people breathing catalyst contaminated air leading to restricted use of external mix guns.
A gun in which the resin and catalyst are mixed internally is often used when solvent emissions are a problem, because internal mixing reduces the amount of atomized catalyst escaping into the atmosphere. Internal mix guns typically have three inputs: resin, catalyst, and air, all three under pressure. In the past, the resin and catalyst are typically mixed in the manifold. The mixture of resin and catalyst are then expelled from a gun through a nozzle along with pressurized air. The resin and catalyst are atomized by the pressurized air.
I some prior spraying devices, the resin and catalyst are introduced into a mixing area where they combine as they flow toward a spray tip or nozzle. A pressurized air stream helps mix the catalyst and resin and also helps expel the catalyst/resin mixture from the nozzle. In such designs, if there is an imbalance in the pressure of the resin and catalyst, the combined resin and catalyst will back up into the supply that has lower pressure, especially if a clog occurs. Furthermore, it is undesirable to introduce catalyst at the same high pressures of the resin since the catalyst is often less viscous and, at times, a serious health risk. It is also difficult to mix the catalyst and resin in the mixing area because, often, the relatively high viscosity catalyst often creates a tunnel through the resin within the mixing area instead of completely mixing with the resin.
What is needed is a system, method and apparatus that will seal a pressure side of a shaft from a non-pressure side of that shaft.


A stripper for stripping a urea/carbamate mixture. The stripper comprises a shell and a plurality of tubes disposed within the shell. A shell-side space is provided between the tubes and the shell. A first heating fluid inlet, a second heating fluid inlet, and a heating fluid outlet are in fluid connection with the shell-side space. The second heating fluid inlet is disposed between the first heating fluid inlet and the heating fluid outlet. Related uses, systems, and methods are provided as well.

High Pressure Strippers are used in urea plants to concentrate urea, by removing the carbamate from a liquid urea/carbamate mixture. The urea/carbamate mixture is a solution of urea, ammonium carbamate, free ammonia and water, coming from a reactor in which urea is formed by the reaction of ammonia and CO2 into ammonium carbamate (also referred to as carbamate) and subsequent dehydration of carbamate to produce urea. The conversion of carbamate into urea is, in practical terms, never complete and the solution leaving the urea reactor always comprises some carbamate and free ammonia.
A common way of removing carbamate and of concentrating the solution involves the use of a tube heat exchanger, called High Pressure Stripper, operating at a similar pressure to that of the Urea Reactor. Under the influence of the heat provided by a heating medium such as steam, the ammonium carbamate in the urea and carbamate mixture decomposes to form gaseous NH3 and CO2. These NH3 and CO2 gases are removed from the stripper. Accordingly, liquid urea is produced which is collected at the bottom of the stripper.
Two categories of high-pressure strippers exist: CO2 strippers and self-strippers.
In CO2 strippers, CO2 is used as a stripping gas. It is fed to the bottom of the High Pressure Stripper and NH3 and CO2 produced during the decomposition of ammonium carbamate are entrained by the CO2 stripping gas.
In self-strippers, no stripping gas is added to the stripper, but NH3 and CO2 formed during the decomposition of ammonium carbamate serve as the stripping gas.
The strippers comprise tubes and a shell, a top end, and a bottom end. During normal use, the top end is situated at the top of the stripper and the bottom end is situated at the bottom of the stripper. At the top end, a urea/carbamate mixture is distributed in the tubes and a gas mixture comprising stripping gas and entrained NH3 and CO formed during carbamate decomposition leave the stripper. At the bottom end, the urea solution is collected. In the case of CO2 strippers, CO2 stripping gas is provided to the bottom end of the carbamate decomposer.
During normal operation, the tubes are installed substantially vertically. They enclose a tube-side space. A shell-side space is disposed between the tubes and the shell. The stripping gas and the urea/carbamate mixture run counter-current through the tube-side space while the urea/carbamate mixture is heated by means of a heating medium in the shell-side space, commonly steam. The urea/carbamate mixture flows into the tubes in a falling film pattern, while the gases rise in the inner part of the tubes.
It would be desirable to scale up such strippers in order to manufacture large volumes of urea in a cost-efficient way. Unfortunately, scaling up these strippers is not always easy and many unforeseen problems tend to occur during upscaling.

High pressure strippers for use in urea plants


A method for frequency transposition in a communication device Or a hearing device, respectively, is disclosed by transforming an acoustical signal into an electrical signal (s) and by transforming the electrical signal from time domain into frequency domain to obtain a spectrum (S). A frequency transposition is being applied to the spectrum (S) in order to obtain a transposed spectrum (S′), whereby the frequency transposition is being defined by a nonlinear frequency transposition function. Thereby, it is possible to transpose lower frequencies almost linearly, while higher frequencies are transposed more strongly. As a result thereof, harmonic relationships are not distorted in the lower frequency range, and at the same time, higher frequencies can be moved to a lower frequency range, namely to an audible frequency range of the hearing impaired person. The transposition scheme can be applied to the complete signal spectrum without the need for switching between non-transposition and transposition processing for different parts of the signal. Therefore, no artifacts due to switching are encountered. A higher transmission quality is obtained because more information is taken into account for the transmission.

Numerous frequency-transposition schemes for the presentation of audio signals via hearing devices for people with a hearing impairment have been developed and evaluated over many years. In each case, the principal aim of the transposition is to improve the audibility and discriminability of signals in a particular frequency range by modifying those signals and presenting them at other frequencies. Usually, high frequencies are transposed to lower frequencies where hearing device users typically have better hearing ability. However, various problems have limited the successful application of such techniques in the past. These problems include technological limitations, distortions introduced into the sound signals by the processing schemes employed, and the absence of methods for identifying suitable candidates and for fitting frequency-transposing hearing aids to them using appropriate objective rules.
The many techniques for frequency transposition reported previously can be subdivided into three broad types: frequency shifting, frequency compression, and reducing the playback speed of recorded audio signals while discarding portions of the signal in order to preserve the original duration.
Among frequency compression schemes, many linear and non-linear techniques including FFT/IFFT processing, vocoding, and high-frequency envelope transposition followed by mixing with unmodified low-frequency components have been investigated. Since harmonic patterns and formant relations are known to be important in the accurate perception of speech, it is also helpful to distinguish spectrum-preserving techniques from spectrum-destroying techniques. Each of these techniques is summarized briefly below.
At present, the only frequency-transposing hearing instruments available commercially are those manufactured by AVR Ltd., a company based in Israel and Minnesota, USA (see http://www.avrsono.com). An instrument produced previously by AVR, known as the TranSonic, has been superseded recently by the ImpaCt and Logicom-20 devices. All of these frequency-transposition instruments are based on the selective reduction of the playback speed of recorded audio signals. This is achieved by first sampling the input sound signal at a particular rate, and then storing it in a memory. When the recorded signal is subsequently read out of the memory, the sampling rate is reduced when frequency-lowering is required. Because the sampling rate can be changed, it is possible to apply frequency lowering selectively. For example, different amounts of frequency-lowering can be applied to voiced and unvoiced speech components. The presence of each type of component in the input signal is determined by estimating the spectral shape; the signal is assumed to be unvoiced when a spectral peak is detected at frequencies above 2.5 kHz, voiced otherwise. In order to maintain the original duration of the signals, parts of the sampled data in the memory are discarded when necessary. U.S. Pat. No. 5,014,319 assigned to AVR describes not only the compression of input frequencies (i.e. frequencies are transposed into lower ranges) but also frequency expansion (i.e. transposition into higher frequency ranges). Other similar methods of frequency transposition by means of reducing the playback speed of recorded audio signals have also been reported previously (e.g. FR-2 364 520, DE-17 62 185). As mentioned, a major problem with any of these schemes is that portions of the input signal must be discarded when the playback speed is reduced (to compress frequencies) in order to maintain the original signal duration, which is essential in a real-time assistive listening system such as a hearing device. This could result in audible distortions in the output signal and in some important sound information being inaudible to the hearing device user.
Linear frequency compression by means of Fourier Transform processing has been investigated by Turner and Hurtig at the University of Iowa, USA (Turner, C. W. and R. R. Hurtig: "Proportional Frequency Compression of Speech for Listeners with Sensorineural Hearing Loss", Journal of the Acoustical Society of America, vol. 106(2), pp. 877–886, 1999), and has led to an international patent application having the publication number WO 99/14 986. This real-time algorithm is based on the Fast Fourier Transform (FFT). Input signals are converted into the frequency domain by an FFT having a relatively large number of frequency bins resulting in a high frequency resolution which is absolutely necessary to achieve a good sound quality with a system based on linear frequency compression. To achieve frequency lowering, the reported algorithm multiplies each frequency bin by a constant factor (less than 1) to produce the desired output signal in the frequency domain. Data loss resulting from this compression of the spectrum is minimized by linear interpolation across frequencies. The output signal is then converted back into the time domain by means of an inverse FFT (IFFT). One disadvantage of this technique is that it is very inefficient computationally due to the large size of the FFT, and would consume too much electrical energy if implemented in a hearing device. Furthermore, propagation delay of signals processed by this algorithm would be unacceptably long for hearing device users, potentially resulting in some interference with their lip-reading ability. In addition, the compression capabilities (i.e. the range of the compression ratio) are limited due to the applied proportional, i.e. linear, compression scheme.
A feature extraction and signal resynthesis procedure and system based on a vocoder have been described by Thomson CSF, Paris in EP-1 006 511. Information about pitch, voicing, energy, and spectral shape is extracted from the input signal. These features are modified (e.g. by compressing the formant. frequencies in the frequency domain) and then used for synthesis of the output signal by means of-a vocoder (i.e. a relatively efficient electronic or computational device or technique for synthesizing speech signals). A very similar approach has also been described by Strong and Palmer in U.S. Pat. No. 4,051,331. Their signal synthesis is also based on modified speech features. However, it synthesizes voiced components using tones, and unvoiced components using narrow-band noises. Thus, these techniques are spectrum-destroying rather than spectrum-preserving.
A phase vocoder system for frequency transposition is described in a paper by H. J. McDermott and M. R. Dean ("Speech perception with steeply sloping hearing loss", British Journal of Audiology, vol. 34, pp. 353–361, December 2000). A non-real-time implementation is disclosed using a computer program. Digitally recorded speech signals were low pass filtered, down sampled and windowed, and then processed by a FFT. The phase values from successive FFTs were used to estimate a more precise frequency for each FFT bin, which was used to tune an oscillator corresponding to each FFT bin. Frequency lowering was achieved by multiplying the frequency estimates for each FFT-bin by a constant factor.
Another system that can separately compress the frequency range of voiced and unvoiced speech components as well as the fundamental frequency has been described by S. Sakamoto, K. Goto, et. al. ("Frequency Compression Hearing Aid for Severe-To-Profound Hearing Impairments", Auris Nasus Larynx, vol. 27, pp. 327–334, 2000). This system allows independent adjustment of the frequency compression ratio for unvoiced and voiced speech, fundamental frequency, the spectral envelope, and the instrument's frequency response by the selection of different filters. The compression ratio for either voiced or unvoiced speech is adjustable from 10% to 90% in steps of 10%. The fundamental frequency can either be left unmodified, or compressed with a compression ratio either the same as, or lower than, that employed for voiced speech. A problem with each of the above feature-extraction and resynthesis processing schemes is that it is technically extremely difficult to obtain reliable estimates of speech features (such as fundamental frequency and voicing) in a wearable, real-time hearing instrument, especially in unfavorable listening conditions such as when noise or reverberation is present.
EP-0 054 450 describes the transposition and amplification of two or three different bands of the frequency spectrum into lower-frequency bands within the audible range. In this scheme, the number of "image" bands equals the number of original bands. The frequency compression ratio can be different across bands, but is constant within each band. The image bands are arranged contiguously, and transposed to frequencies above 500 Hz. In order to free this part of the spectrum for the image bands, the amplification for frequencies between 500 and 1000 Hz decreases gradually with increasing frequency. Frequencies below 500 Hz in the original signal are amplified with a constant gain.
In U.S. Pat. No. 4,419,544 to Adelman, the input signal is subjected to adaptive noise canceling before filtering into at least two pass-bands takes place. Frequency compression is then carried out in at least one frequency band.
Other techniques described previously include the modulation of tones or noise bands in the low-frequency range based on the energy present in higher frequencies (e.g. FR-1 309 425, U.S. Pat. No. 3,385,937), and various types of linear and non-linear transposition of high-frequency components which are then superimposed onto the low-frequency part of the spectrum (e.g. U.S. Pat. No. 5,077,800 and U.S. Pat. No. 3,819,875). Another approach (WO 00/75 920) describes the superposition of the original input signal with several frequency-compressed and frequency-expanded versions of the same signal to generate an output signal containing several different pitches, which is claimed to improve the perception of sounds by hearing-impaired listeners.
Problems with each of the above described methods for frequency transposition include technical complexity, distortion or loss of information about sounds in some circumstances, and unreliability of the processing in difficult listening conditions, e.g. in the presence of background noise.

Method for frequency transposition and use of the method in a hearing device and a communication device


An oxygen sensor having a main body member with an interior chamber, made from material which is an oxygen ion conducting solid electrolyte when at specified temperatures. Electrodes made from material which is porous to oxygen molecules are positioned opposite each other on the main body member, within the interior chamber an d on the outside of the main body. Via a port which extends through the main body, changes in the absolute pressure of gas to be tested in the environs of the outer electrode are transmitted to the gas in the environs of the inner electrode. As a result of reference gas being introduced into the interior chamber of the main body through an orifice at a pressure sufficient to maintain the rate of flow at its critical (and therefore constant) rate of flow, the environs of the inner electrode are occupied by reference gas and a flow of gas results, through the main body member from the region of the inner electrode and out through the port.. In optional embodiments, only a portion of the test gas directly impinges upon the outer surface of the outer electrode to minimize it being cooled, the main body member is heated to specified temperatures, means are provided to ensure a flow of test gas past the sensor, and/or the outside electrode periodically is exposed to reference gas to calibrate the sensor for cell constant.

In certain applications, it is desired to monitor the oxygen content of gases more or less continuously. A system which does this effectively may be used, for example, to monitor the gaseous effluent from industrial boilers, kilns, ovens, internal combustion engines, driers, heat treating furnaces, incinerators, refinery process units, gas turbines scrubbers and the like. Based on the information so gleaned, the amount of oxygen present may be adjusted to desired levels. For example, the air being introduced into the combustion phase of a boiler may be regulated to achieve optimum efficiency, and to reduce nitrous oxide and/or sulphur dioxide emissions. Insufficient oxygen, which can cause too high smoke opacity, slag buildup, boiler tube fouling, decreased heat transfer, excessive maintenance, and wasted fuel, may be avoided, as also can an excess of oxygen which can cause waste of energy by heat loss. Such monitoring systems can also be adapted to act as sources to enable feedback systems to effectuate such adjustments automatically and continuously.
One means for so monitoring the oxygen content of such gases works on the principle of a zirconium oxide fuel cell oxygen sensor. Typically, such sensors consist of a ceramic tube made from zirconium oxide that has been stabilized with yytrium and has porous platinum electrodes coated opposite each other on both its inner and its outer surfaces at its sensing end. When the cell is heated to a temperature above 600.degree. C. (1100.degree. F.) the ceramic material becomes permeable to oxygen ions. Vacancies in its lattice structure permit such ions to pass through it, thus rendering the cell into an oxygen ion conducting solid electrolyte. When the number of oxygen molecules per unit volume is greater at one plate of the cell than at the other, oxygen ions will migrate from the former to the latter. The platinum electrodes on each side of the cell wall provide catalytic surfaces for the change of oxygen molecules into oxygen ions and vice versa. Thus, oxygen molecules entering the cell through an electrode gain electrons to become ions which enter the electrolyte. Simultaneously, at the other electrode, the oxygen ions lose electrons and are released from the surface of the electrode as oxygen molecules. This flow creates an electron imbalance which produces a voltage potential between the electrodes. The magnitude of that potential is a function of the temperature of the cell and the relative partial pressure on each side of the cell. Partial pressure is defined as the pressure exerted by each component in the mixture that goes to make up the gas. It may be calculated as follows: EQU Pi=Ni.times.R.times.T/V
where
pi=the partial pressure, PA1 Ni=the number of molecules of the specie, PA1 R=the Universal Gas constant, PA1 T=temperature (absolute scale), PA1 and V=volume. PA1 T=Absolute temperature of cell PA1 R=Universal Gas Constant PA1 F=Faraday's Constant PA1 P1=Partial Pressure of oxygen in the reference gas PA1 P2=Partial Pressure of oxygen in the monitored gas PA1 C=a Cell Constant for each individual cell, PA1 and Ln(P1/P2) is the natural logarithm of ratio P1/P2.
The partial pressure of the component gas "i" is then the same as if it occupies the same volume at the same temperature in the absence of other gases.
The relationship between the oxygen partial pressure at the monitored side and that at the reference gas side (typically air, which is 20.95% oxygen by volume), the temperature, voltage output, and cell constant of the individual cell are defined by the "Nernst" equation as follows: EQU E=RT/4F.times.Ln(P1/P2)+C
where E=Voltage out
The electrical voltage output of such a cell may be utilized, for example, in a closed loop combustion control system which uses the oxygen sensor output signal to "trim" the fuel/air mixture ratio. In such systems, the readings for actual stack gas oxygen content are compared with a desired set point. An appropriate control system output is generated to adjust automatically the fuel/air ratio, by such means as changing the amount of combustion air to the burner and/or the amount of fuel admitted to the burner, adding diluents and/or oxygen, etc., thereby assuring that the desired oxygen set point is maintained. The desired effect of this is to achieve optimum combustion efficiency by regulating exactly the amount of oxygen to achieve complete combustion of the fuel. The Nernst equation "C" factor is to adjust output readings for peculiarities of the individual cell, such as those which may be induced by physical characteristics, damage, and/or conditions which are unique to that particular cell. Its value may be determined and utilized to correct the output readings by such means as a solenoid actuated bypass conduit through which reference gas may be periodically introduced to the environs of the outer electrode surface. The "reading" while that is being done will then be that of the "C" factor alone; all other factors affecting the cell output at that instant thereby having then been eliminated or at least so minimized as to have no material effect on the resulting readings.
It is also desired to effectuate such monitoring by comparable means and mechanisms to those previously described in situations where ambient phenomena may induce false output readings which render the cell ineffectual as a practical matter. One example of this is where there is a differential between the absolute pressure of the gas at one of the electrodes from that at the other. An even more difficult example is where such a differential in absolute pressure is pulsating. Thus, in an internal combustion diesel engine, the effluent gas not only is at an absolute pressure differential with respect to the reference, but also, because of the valving in the engine, that pressure pulsates through the exhaust system. Conditions of this type can cause a sensor of the type described to exhibit erroneous readings.
An explanation of this begins by noting that the principle involved in the operation of cells of the type described above is the migration of oxygen ions through the walls of the cell that is motivated by a disparity in the oxygen pressure as between the two masses of gas. To be an accurate indicator of the proportion of oxygen content in the test gas, this migration, and the resulting imbalance in electrical potential, should be solely the result of the differential between the partial pressure of the oxygen in the gas that is on the test side and that of the oxygen in the gas that is on the reference side of the cell. However, the magnitude of such migration may be influenced as well by a differential in the absolute pressure of the reference environment and that of the environment being sampled. The reason for this result is that the effect of an increase in absolute pressure is to compress the gas and thus "densify" it; i.e., to concentrate a greater number of oxygen molecules into an equivalent volume. But the sensor is capable only of reacting to oxygen pressure differentials. Its outer electrode now being exposed to more oxygen molecules over the same area for that electrode due to the "densification" which has occurred, the sensor "reads" this as if the composition of the test gas had changed through an increase in the proportion of its oxygen constituent, which it has not. To interpret the resulting output as indicative of an oxygen partial pressure differential reading therefore, is erroneous since it has not been factored to take this absolute pressure differential element into account. While theoretically it might be possible to factor the cell output to take such absolute pressure differentials into account, this would be an unrealistically complex approach as a practical matter. In a pulsating pressurized environment particularly, such as that present in an internal combustion engine exhaust system, not only is such an aberration produced by the addition in absolute pressure, but the aberration produced is unstable since the added pressure so applied is constantly changing due to the exhaust valve operation of the engine. It will be apparent then why, although the use of devices of the type described is desired, that has not been practical in some situations because of the inaccuracy of the results produced.
Accordingly, it is an object of this invention to provide means to detect the oxygen content of a gaseous environment.
Another object of this invention is to provide such means for use in monitoring such oxygen content on a more or less continuous basis.
Yet another object of this invention is to provide means for achieving one or more of the foregoing objectives that is adapted for use in contexts wherein such gaseous environments are at differing absolute pressures.
Still another object of this invention is to provide means for achieving one or more of the foregoing objectives that is adapted for use in contexts wherein such gaseous environments are pulsating.
Yet another object of this invention is to provide means for achieving one or more of the foregoing objectives that is adapted for producing repetitive output signals to be utilized as corrective feedback sources.
Another object of this invention is to provide means for achieving one or more of the foregoing objectives that is adapted for use in internal combustion engines.


An apparatus and method are disclosed for decoding servo data recorded on a magnetic disk drive and detecting pinned layer reversals and signal errors, for example, errors due to noise. The servo data is encoded using wide-bi-phase encoding. This encoding is detected by a magneto-resistive sensor that senses the magnetization in domains passing by the sensor. The decoder includes an A/D converter for sampling the signals emitted by the sensor, to provide a sequence of the encoded data. A trellis, such as a Viterbi trellis, is employed to decode the samples generated by the converter. The trellis includes nodes representing states, connected by paths representing transitions, among the nodes. A quality value is generated for the transitions, the quality value representing the distance between each sample in the sequence output by the A/D converter and a corresponding expected sample. By applying servo data to two trellises, each corresponding to a different pinned layer magnetic orientation, and comparing the quality values produced, the correct pinned layer orientation may be selected.

1. Field of the Invention
The invention relates generally to the detection of pin layer reversal (PLR) in a disk drive using a magneto-resistive head and also to signal degradation, for example, damage to the disk drive, and/or domain wall movement of information recorded in the servo portion on the disk.
2. Background Information
A magneto-resistive head used in a disk drive includes a pinned layer of magnetic material which ideally has a fixed direction. As the magnetic domains on the disk pass under the head, the direction of the magnetization of each domain either adds to, or subtracts from, the magnetization of the pinned layer. The head senses the direction of each domain by means of a change in resistance of the head in response to the sum of the magnetization of the domain and that of the pinned layer. The direction of the pinned layer magnetization is set at the factory and the decoding of data on the disk drive is determined by that direction. That is, the direction is assumed in the circuitry that detects and decodes the data.
However, from time to time, the magnetization of the pinned layer may reverse, due to various causes. This results in a reversal of the perceived bits on the disk, i.e. zeros are interpreted as one's and one's interpreted as zero's. There is a need to detect pinned layer reversal. Also there is a need to detect noise, for example noise introduced by damage to the head or disk, or by domain wall movement that may occur in the soft under layer used in perpendicular recording systems.

Wide-biphase-detector quality monitor for sensing of pin layer reversal