Patents Examined by Tiep H. Nguyen
  • Patent number: 5576856
    Abstract: The liquid crystal display device of this invention includes: a pair of substrates facing each other and a display medium sandwiched between the pair of substrates. In this liquid crystal display device, at least one of the pair of substrates is a flexible film having polarizer properties and the display medium includes a liquid crystal phase and a polymer phase.
    Type: Grant
    Filed: March 10, 1995
    Date of Patent: November 19, 1996
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Naoko Kawazu, Shinji Shimada
  • Patent number: 5576859
    Abstract: A device for improving a contrast of a liquid crystal screen by using an opaque mask. The display screen includes a first plate, on one face of which are deposited elements with controlled transparence or reflectance and thin film components controlling these elements, and a back plate covering a face of the first plate including the elements with controlled transparence or reflectance and the thin film components. The elements are separated by opaque bands into lines and columns forming a grid. The opaque bands are deposited at least partially on the plate including the elements and the thin film components.
    Type: Grant
    Filed: August 29, 1994
    Date of Patent: November 19, 1996
    Assignee: Thomson-LCD
    Inventor: Donald Castleberry
  • Patent number: 5569929
    Abstract: A position detecting apparatus comprises a double-beam producing device for producing two beams different in frequency from each other, which are guided to irradiate a diffraction grating on an object to be inspected in two predetermined directions, and a detector photoelectrically detecting through an objective optical system diffracted light produced by the diffraction grating, in which the double-beam producing device comprises a light source for supplying a beam of a single wavelength or multiple wavelengths, a beam splitting device for splitting the beam from the light source into two predetermined beams, a relay optical system for converging the two split beams at a predetermined position, and a frequency difference producing device disposed at or near a converging position by the relay optical system, for producing a predetermined frequency difference between the two split beams.
    Type: Grant
    Filed: June 6, 1995
    Date of Patent: October 29, 1996
    Assignee: Nikon Corporation
    Inventors: Hideo Mizutani, Kazuya Ota
  • Patent number: 5570210
    Abstract: A liquid crystal device including a liquid crystal layer comprising a liquid crystal of a dispersed type in which liquid crystal molecules are randomly distributed so that an incident light impinging against the liquid crystal molecules scatters to produce a white display spot. A polarizer and an analyzer are arranged on either side of the first and second transparent plates. A directional backlight is arranged on the outside of the polarizer for supplying light having a directivity in the direction perpendicular to the first and second transparent plates toward the polarizer.
    Type: Grant
    Filed: January 31, 1994
    Date of Patent: October 29, 1996
    Assignee: Fujitsu Limited
    Inventors: Hidefumi Yoshida, Kazutaka Hanaoka, Kimiaki Nakamura, Hideaki Tsuda, Fumiaki Yamada
  • Patent number: 5568086
    Abstract: A Doherty-type power amplifier suitable for satellite telecommunication systems provides linear amplification of noise-like RF signals that have multiple carriers spread over a large instantaneous bandwidth. Efficiencies of 40% to 50% are achieved using PHEMT devices. The power amplifier includes a carrier amplifier that operates a low power levels and a peak amplifier that operates at high power levels. For low power levels, the carrier amplifier delivers its output into twice the optimum load resulting in high efficiency, while the peak amplifier is turned off. At high power levels, both the carrier and the peak amplifier is working into an optimum load and maximum power is delivered. Output matching sections are used to transform the very low optimum load impedance of the PHEMT devices prior to phase shifting and combining.
    Type: Grant
    Filed: May 25, 1995
    Date of Patent: October 22, 1996
    Assignee: Motorola, Inc.
    Inventors: Jack J. Schuss, Peter R. Maloney, David M. Upton, Robert J. McMorrow
  • Patent number: 5559470
    Abstract: A fast parasitic-insensitive continuous-time filter and equalizer integrated circuit that uses an active integrator is described. Circuit techniques for excess-phase cancellation, and for setting the corner-frequency of the filter and equalizer are also described. These techniques result in a filter and equalizer chip with performance independent of process, supply, and temperature without employing phase-lock loops. This 20MHz 6th order Bessel filter and 2nd order equalizer operate from 5V, and generate only 0.24% (-52dB) of total harmonic distortion when processing 2Vp-p differential output signals. The device is optimized to limit high-frequency noise and to amplitude equalize the data pulses in hard disk read-channel systems. The device supports data rates of up to 36Mbps, and is built in a 1.5 .mu./4GHz BiCMOS technology.
    Type: Grant
    Filed: February 17, 1995
    Date of Patent: September 24, 1996
    Assignee: Micro Linear Corporation
    Inventors: Carlos A. Laber, Paul R. Gray
  • Patent number: 5559468
    Abstract: A linear amplifier (103) has a negative feedback loop that has a closed loop gain and a forward path gain. The negative feedback loop is closed, such that quick changes in the closed loop gain are prevented, thereby reducing splatter. When the negative feedback loop is opened, quick changes in the closed loop gain are also prevented, thereby reducing splatter.
    Type: Grant
    Filed: June 28, 1993
    Date of Patent: September 24, 1996
    Assignee: Motorola, Inc.
    Inventors: Paul H. Gailus, Ronald H. Chapman, Jeffrey B. Wilhite
  • Patent number: 5557433
    Abstract: In a TN LCD, a prism lens film and a wave lens film are disposed on the incoming and outgoing sides of a liquid crystal panel, respectively, to obtain an image wide in visual angle and good in its quality. Thus, outgoing light having a sharp directivity, can be obtained from light emitted from a surface illuminant and having a gradually varying directional property by the prism lens film. Further, with a louver film provided in front of the prism lens film, all the light traveling in the diagonal direction can be cut off so that substantially parallel light enter the liquid crystal panel. Since the light in which a variation in retardation is next to nothing, is diffused by the wave lens film, a wide visual-angle representation free of a dependence on the visual angle can be obtained.
    Type: Grant
    Filed: February 13, 1995
    Date of Patent: September 17, 1996
    Assignee: NEC Corporation
    Inventors: Muneo Maruyama, Toshihiko Ueno, Hiroshi Hada, Masatake Baba
  • Patent number: 5557101
    Abstract: The detector comprises a disc-like reel table adapted to support a tape reel thereon, the reel table having a reflective underneath surface and an array of concentric spaced-apart cutouts uniformly disposed on the reflective surface along a common imaginary circle whose center coincides with a rotational axis of the tape reel, each of the cutouts having a light scattering surface capable of reducing the intensity of a light beam incident thereupon to an appreciable level. A light emitter is located in an opposing relationship with respect to the reel table for projecting the light beam toward the reflective underneath surface and the light scattering surface of the reel table. Positioned adjacent to the light emitter is a light receiver for receiving the light beam reflected back from the reel table to produce a pulse signal when the intensity of the received light beam varies over time in a pulse pattern.
    Type: Grant
    Filed: September 9, 1993
    Date of Patent: September 17, 1996
    Assignee: Daewoo Electronics Co., Ltd.
    Inventor: Jae-Kyu Choi
  • Patent number: 5555476
    Abstract: Disclosed is a microlens array sheet for a liquid crystal display including a first substance layer and a second substance layer having a refractive index less than that of the first substance layer. A plurality of minute unit lenses are formed by providing concaves and/or convexes to an interface between the first and second substance layers. When a ray having entered into the sheet from the normal-line direction of the second substance layer exits from the surface of the first substance layer, an refractive angle relative to the normal line of the surface of first substance layer is not less than 30 degrees. When this microlens array sheet is attached to the surface of a liquid crystal cell of a liquid crystal display, an improved large angle of visibility can be obtained.
    Type: Grant
    Filed: August 24, 1994
    Date of Patent: September 10, 1996
    Assignee: Toray Industries, Inc.
    Inventors: Motoyuki Suzuki, Tetsuo Uchida, Kazuo Matsuura
  • Patent number: 5552747
    Abstract: A driver circuit, for an electronic switch which is to be operated from a clock signal, comprises an inverter driven by the clock signal, and a voltage doubler which is connected to supply the inverter and connected to be driven by the complementary clock signal.
    Type: Grant
    Filed: June 1, 1995
    Date of Patent: September 3, 1996
    Assignee: SGS-Thomson Microelectronics S.r.l.
    Inventors: Luciano Tomasini, Rinaldo Castello, Pierangelo Confalonieri
  • Patent number: 5548423
    Abstract: A method of driving positive-type super-twisted nematic liquid crystal shutters by using a low-voltage CMOS-LSI maintaining a contrast ratio of greater than 100 without being colored. When an inter-electrode voltage at which the color of the liquid crystal pixels constituting the liquid crystal shutters starts to extinguish is denoted by VL and an inter-electrode voltage that minimizes the transmission factor of the liquid crystal pixels is denoted by VM, a peak value of the AC voltage applied to the opposing electrode is set to be (VL+VM)/2, and a peak value of the AC voltage applied to the signal electrodes is set to be (VL-VM)/2. The AC voltage applied to the opposing electrode and the AC voltage applied to the signal electrodes are set to be in phase with each other to select a bright level and are inverted relative to each other in phase to select a dark level.
    Type: Grant
    Filed: December 13, 1993
    Date of Patent: August 20, 1996
    Assignee: Citizen Watch Co., Ltd.
    Inventor: Masaaki Natsunaga
  • Patent number: 5546048
    Abstract: A push-pull circuit formed of transistors drives a peaking capacitor of an amplifier circuit to enhance charge and discharge of the peaking capacitor. This reduces a bias current, resulting in reduction of a power consumption. A feedback impedance is connected to an emitter of a transistor to feed an output signal back to an input of the amplifier circuit as a current signal in a wide frequency range. Thus, a high-power, wideband amplifier is accomplished.
    Type: Grant
    Filed: August 31, 1993
    Date of Patent: August 13, 1996
    Assignee: Hitachi, Ltd.
    Inventors: Yuji Sano, Sadao Tsuruga, Kouji Kitou, Michitaka Ohsawa
  • Patent number: 5543746
    Abstract: A temperature compensation circuit is disclosed that includes a first field-effect transistor (FET), a second FET, a resistor, and current generating circuitry. The second FET has a larger current conducting channel than the current conducting channel of the first FET, and the gate of the second FET is coupled to the gate of the first FET. The resistor is coupled between a first node that is common with the source of the first FET and a second node that is common with the source of the second FET. The current generating circuitry generates and maintains substantially equal drain currents in the first and second FETs.
    Type: Grant
    Filed: August 22, 1995
    Date of Patent: August 6, 1996
    Assignee: National Semiconductor Corp.
    Inventor: James R. Kuo
  • Patent number: 5541418
    Abstract: Apparatus for the inspection of the end surface of a cylindrical object including means for irradiating the end surface of the object, detector means for detecting radiation reflected by the end surface substantially parallel to the axis of the object and calculator means for calculating the proportion of the end surface which has reflected radiation directly to the detector means, wherein the means for irradiating comprises a ring source the center of the ring being substantially co-incident with the axis of the object and being substantially transparent to reflected radiation so that light reflected to the detector means passes unhindered through the ring, the ring source having associated therewith means permitting substantially uniform irradiation across the said end surface.
    Type: Grant
    Filed: September 15, 1993
    Date of Patent: July 30, 1996
    Assignee: British Nuclear Fuels plc
    Inventors: Adam K. Ainsworth, Reginald P. Glenville, Iain A. McLean
  • Patent number: 5541751
    Abstract: The light scan type display device includes a display medium laid between two opposed substrates, which is driven in response to a light signal. One of the substrates has plural light waveguides provided in parallel and for transmitting a light signal, plural signal electrodes ranged in parallel and orthogonally with the light waveguides and for transmitting a light signal, pixel electrodes formed in a matrix manner, and light switching elements formed of a photoconductive material at crosspoints between the signal electrodes and the light waveguides in a manner to abut on the signal electrodes and the pixel electrodes. Further, the one substrate includes micro lenses for condensing ambient light to pixel openings. The micro lenses serve to condense the light from the backlight onto the pixels for prevent intrusion of any other light except the light scan signal into the switching element.
    Type: Grant
    Filed: December 8, 1993
    Date of Patent: July 30, 1996
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Yukihiro Sumida, Yoshihiro Izumi, Sayuri Fujiwara
  • Patent number: 5537233
    Abstract: In a display housing, first and Second liquid-crystal panels are disposed in parallel with each other, and a fluorescent lamp is positioned beside both ends of a gap between these panels. Thus, when used for a transmission type display, e.g. an OHP, the first liquid-crystal panel for light shutter is set in a transmission condition to transmit light from a light source for the OHP or the like and to irradiate the second liquid-crystal panel for displaying an image, thereby projecting the image in a magnified size onto a screen or the like. When used for a direct-vision type display, e.g. a monitor for a personal computer or the like, the first liquid-crystal panel is set in a shading condition to effect diffuse reflection of light from the fluorescent lamp by the first liquid-crystal panel and to irradiate the second liquid-crystal panel, thereby providing a direct-vision image.
    Type: Grant
    Filed: November 16, 1994
    Date of Patent: July 16, 1996
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Norio Miura, Hisao Uehara, Atsuyoshi Tanioka, Kazuhiko Moriwaki, Makoto Shimizu, Masahiro Okuyama
  • Patent number: 5537236
    Abstract: A liquid crystal display system comprising a first display member overlying a second display member. Each member comprises two transparent layers (such as glass), coated with polariser and separated by a layer of liquid crystal. Each member has a set of individually actuable display elements. The display elements in the second member, and are visible through the first member.
    Type: Grant
    Filed: May 18, 1994
    Date of Patent: July 16, 1996
    Assignee: Meggitt (UK) Limited
    Inventor: Robert W. Young
  • Patent number: 5534692
    Abstract: A method for detecting the point of origin of a position sensor such as an optical linear scale by first displacing an object member whose position is to be determined until it butts against a mechanical stopper, then determining the position of the object member at the mechanical stopper and using that position as a reference position for the point of origin, and thereafter detecting the position of the object member by means of the position sensor, thereby detecting the position of the object member relative to the point of origin. In another embodiment, a first point of origin signal is obtained from an optical linear scale used as a position sensor and stored in response to latching signal generated at an end point of travel of the object member. Subsequently, when a second point of origin signal from the optical linear scale is compared with the first point of origin signal, any deviation from the first point of origin signal may be corrected based on the result of the comparison.
    Type: Grant
    Filed: September 8, 1993
    Date of Patent: July 9, 1996
    Assignee: Sony Corporation
    Inventor: Akihito Nakayama
  • Patent number: 5530574
    Abstract: A liquid crystal cell (60) for an optical display system has a first transparent electrode structure (62) including plural separate display electrodes (72A-72E) spaced apart from and generally parallel to a second electrode structure (64) including a common electrode (106) opposing the display electrodes across a thin layer (76) of liquid crystal material captured between the two electrode structures. Each display electrode has left (92A-92E) and right (94A-94E) ends having respective electrical contact areas (96A-96E, 98A-98E). The left and right ends of each display electrode are electrically driven with a drive signal (V.sub.DRIVE (A-E)). The common electrode has top (116) and bottom (118) ends located adjacent respective top (108) and bottom (110) side margins of the second electrode structure and having top center (120) and bottom center (122) locations with respective top and bottom electrical contact areas (124, 126).
    Type: Grant
    Filed: March 15, 1994
    Date of Patent: June 25, 1996
    Assignee: Tektronix, Inc.
    Inventors: Lyle R. Leavitt, Marshall J. Pinder