Patents Examined by Stanley D. Miller
  • Patent number: 5157525
    Abstract: The contrast or absolute brightness of a multiplexed LCD is maintained at its preselected value using a feedback arrangement which includes an LCD element functioning as a reference element. The reference element is not used to display information but is continually driven ON and OFF. The average transmissivity of the ON and OFF states is determined and compared with a reference value, the result of the comparison being used to control the voltage levels of the drive waveforms applied to the LCD. By selecting appropriate ratios between the ON and OFF times of the reference element, the LCD can be operated to give optimum contrast, or may have its absolute brightness varied. Control may be effected remotely by reprogramming the microprocessor which determines the timing of the drive waveforms.
    Type: Grant
    Filed: October 23, 1990
    Date of Patent: October 20, 1992
    Assignee: EEV Limited
    Inventors: Timothy J. Eaton, Roger J. Pittock
  • Patent number: 5155380
    Abstract: A clock switching circuit comprises a multiplexer, a gate, a first detector, a second detector and a state machine. The multiplexer receives two clock signals and outputs one of them through the gate. The first detector is coupled to the output of the multiplexer and the second detector is coupled to the output of the gate. The state machine controls the output of the gate and the multiplexer in response to signals from the first and second detector, and prevent glitches from being output by the gate.
    Type: Grant
    Filed: April 12, 1991
    Date of Patent: October 13, 1992
    Assignee: Acer Incorporated
    Inventors: Ching-Tung Hwang, Hsiang-Hsing Sung
  • Patent number: 5155381
    Abstract: The power switch driver is a controlled 4-terminal device for substantially capacitive load, e.g power MOSFET. The switching speed, efficiency and reliability are very high. The switching frequency is inherently limited. The bias supply of the driver may be floating or grounded. The output voltage is approximately two times higher than supply voltage. The energy delivered to the capacitive load is recovered. The driver comprises an inductor for attaining a current and providing binary output voltage. One switch selectively applies the current having any polarity to the supply voltage source. Another switch selectively applies the current having one polarity to ground. A diode applies the binary output voltage having a reverse polarity to ground.
    Type: Grant
    Filed: February 2, 1990
    Date of Patent: October 13, 1992
    Inventor: Zdzislaw Gulczynski
  • Patent number: 5155607
    Abstract: An optical modulation display device is disclosed, comprising a polymer matrix having dispersed therein a liquid crystal composition containing a photochromic compound as a constituting component, or comprising a photochromic polymer matrix having dispersed therein a liquid crystal composition. The display device provides a wide area and flexible display which can be driven without using a matrix addressing system.
    Type: Grant
    Filed: March 15, 1991
    Date of Patent: October 13, 1992
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Akinori Inoue, Ryojiro Akashi, Yutaka Akasaki
  • Patent number: 5155611
    Abstract: A liquid crystal display comprises a pair of substrates provided with an electrode arrangement in matrix form. A chiral smectic C phase liquid crystal material is interposed between the substrates. In the liquid crystal layer, each pixel consists of a number of micro-domains which can be compared to polycrystal line structures. Interaction between adjacent pixels through well ordered liquid crystal structure is suppressed by virtue of the micro-domains.
    Type: Grant
    Filed: January 21, 1992
    Date of Patent: October 13, 1992
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Shunpei Yamazaki, Masahiko Sato, Toshiji Hamatani
  • Patent number: 5155387
    Abstract: A circuit employable as a differential multiplexer (10, 310, or 610) or as a differential logic gate (110, 210, 250, 410, or 510) of either the OR/NOR or EXCLUSIVE OR/EXCLUSIVE NOR type contains four pass gates that operate on four circuit input signals and are controlled by two additional circuit input signals. Two of the pass gates drive a bipolar transistor serially coupled to a first FET driven from the other two pass gates. Likewise, the second pair of pass gates drive another bipolar transistor serially coupled to another FET driven from the first pair of pass gates. The bipolar transistors supply respective circuit output signals. The two FETs are of a first polarity. The circuit preferably includes a pair of FETs of a second polarity opposite to the first polarity. The second pair of FETs are arranged so as to provide output pull-up/pull-down assistance for the bipolar transistors.
    Type: Grant
    Filed: July 8, 1991
    Date of Patent: October 13, 1992
    Assignee: North American Philips Corp.
    Inventors: Thomas D. Fletcher, Edward A. Burton
  • Patent number: 5155613
    Abstract: A driving circuit for liquid crystal display is disclosed and includes a circuit for outputting driving signals to a ferroelectric liquid crystal display in order to construct visual information in the display and a voltage source for supplying a predetermined voltage such that when the display system is switched off the circuit means outputs an erasing signal to the liquid crystal display for erasing all of the visual information displayed in the display and eliminates phantom figures from appearing when the display is reused.
    Type: Grant
    Filed: August 23, 1991
    Date of Patent: October 13, 1992
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventor: Hiroyuki Sakayori
  • Patent number: 5155610
    Abstract: The invention relates to a method of providing a surface layer on a substrate, which surface layer can bring about an inclined orientation of the molecules of the liquid crystalline layer applied to the surface layer at the interface between the surface layer and the liquid crystalline layer. The surface layer is manufactured from a liquid crystalline auxiliary layer in which the orientation of at least a part of the molecules is permanently fixed.
    Type: Grant
    Filed: June 20, 1991
    Date of Patent: October 13, 1992
    Assignee: U.S. Philips Corporation
    Inventors: Rifat A. M. Hikmet, Dirk J. Broer
  • Patent number: 5155382
    Abstract: A master/slave latch circuit employs a single-wire clock, with the clock being applied to only N-channel transistors in the master latch and to only P-channel transistors in the slave latch so that a race-through condition is alleviated in the event of clock skew. The circuits are of ratioless operation, since P-channel transistors are used in each circuit to pull the high side to the supply voltage, and N-channel transistors are used on the low side to assure a zero voltage level. Input to each latch is to the gates of a P-channel pull-up and an N-channel pull-down, while the storage node is between the two clocked transistors. The level of the storage node is inverted and fed back to at transistor across one of the clocked transistors, the one on the high side for the master latch and the low side for the slave latch, and these feedback transistors are of a channel type to support the ratioless scheme.
    Type: Grant
    Filed: February 7, 1992
    Date of Patent: October 13, 1992
    Assignee: Digital Equipment Corporation
    Inventors: William C. Madden, Vidya Rajagopalan
  • Patent number: 5153760
    Abstract: An optical shutter operated device includes a reflector to reflect incident light and a liquid crystal light shutter interposed in front of the reflector. A photovoltaic cell is disposed behind the shutter and is illuminated by the incident light thereby supplying a control voltage to the liquid crystal light shutter for causing it to alternate cyclically between a relatively transparent state and a relatively opaque state.
    Type: Grant
    Filed: June 13, 1990
    Date of Patent: October 6, 1992
    Inventor: Adel A. A. Ahmed
  • Patent number: 5153753
    Abstract: The invention is directed to an active matrix-type liquid crystal display using a horizontal MIM device as a non-linear resistance device. The layers of the metal-insulator-metal elements are formed in a horizontal direction and use a hard carbon film as the insulator layer of the horizontal MIM device. The hard carbon film comprises carbon and hydrogen and a constituent element such as a group III element, group IV element, group V element, alkali metal element, alkaline earth metal element, nitrogen atoms, oxygen atoms, chalcogen atoms or halogen atoms, and has typical specific resistivities of from 10.sup.4 to 10.sup.13 ohm.cm. The claimed devices are economical to produce and substantially free from short circuits caused by pinholes or voids in the insulator layer. In a preferred embodiment, the electrodes of the MIM device are inter-digital in shape.
    Type: Grant
    Filed: April 10, 1990
    Date of Patent: October 6, 1992
    Assignee: Ricoh Company, Ltd.
    Inventors: Eiichi Ohta, Yuji Kimura, Hitoshi Kondo
  • Patent number: 5153469
    Abstract: A biasing network for use in conjunction with a mixer employing field effect transistors which provides for minimum conversion loss over a range of process and temperature conditions. The biasing circuit includes a first field effect transistor having a small gate periphery which is configured as a current source, a second or reference field effect transistor having a gate periphery substantially equal to the gate peripheries of the transistors in the mixer to which the biasing circuit is providing DC biasing voltages and a voltage divider which is functional in defining operating conditions for the reference transistor.
    Type: Grant
    Filed: April 25, 1991
    Date of Patent: October 6, 1992
    Assignee: Rockwell International Corporation
    Inventors: Brian E. Petted, Jeffrey P. Ortiz, Leo J. Wilz, Robert J. Baeten
  • Patent number: 5153755
    Abstract: A liquid crystal optical device of this invention includes one substrate having a substrate surface on which one electrode is formed, the other substrate having a substrate surface on which the other electrode is formed, a first aligning film covering one electrode of one substrate and at least a portion of the substrate surface, a second aligning film covering the other electrode of the other substrate and at least a portion of the substrate surface, a dielectric layer disposed between at least one of the first and second aligning films and the electrode corresponding thereto, a sealing member for bonding the one substrate and the other substrate to each other with a predetermined gap therebetween to oppose the substrate surfaces of the one and the other substrates on which the electrodes are formed, and sealing the gap, and a ferroelectric liquid crystal material sealed in the gap surrounded by one and the other substrates disposed oppositely and the sealing member.
    Type: Grant
    Filed: December 3, 1990
    Date of Patent: October 6, 1992
    Assignee: Casio Computer Co., Ltd.
    Inventor: Masakatsu Higa
  • Patent number: 5153761
    Abstract: A high performance light valve for optimizing the switching of a liquid crystal on an area basis. The light valve uses a transparent charge separation layer to allow for the accumulation of photo-generated charges. The light valve concentrates the light absorption in a narrow charge generation region where high electric fields are present from the junction of dissimilar semiconductor materials. The light valve has a switching characteristic dominated by the light and dark carrier densities in a narrow reversed biased region.
    Type: Grant
    Filed: November 22, 1991
    Date of Patent: October 6, 1992
    Assignee: Everex Systems, Inc.
    Inventor: Guy A. Marlor
  • Patent number: 5153526
    Abstract: A numerical control type oscillator whose output oscillation frequency is controlled depending on input numerical data, comprises: first accumulation means for accumulating a first set value which is set depending on the input numerical data with a first frequency and sequentially outputting the accumulated value; second accumulation means for accumulating a second set value which is set depending on the input numerical data with a second frequency and varying the first set value by a predetermined value temporarily when the accumulated value reaches a predetermined maximum value; and frequency generation means for outputting a frequency depending on an output of the first accumulation means as an oscillation frequency.
    Type: Grant
    Filed: May 23, 1991
    Date of Patent: October 6, 1992
    Assignee: Sony Corporation
    Inventors: Katsuya Hori, Eiichiro Morinaga
  • Patent number: 5153756
    Abstract: A liquid crystal display apparatus detects and regulates its display contrast. A liquid crystal display unit is provided therein with a pair of liquid crystal cells for use in detection of the display contrast. Incident light is detected through the cells, and the detected results are fed back to control a drive voltage applied to the liquid crystal display unit so as to automatically regulate the display contrast at optimum level.
    Type: Grant
    Filed: May 3, 1991
    Date of Patent: October 6, 1992
    Assignee: Seiko Instruments Inc.
    Inventor: Toshimasa Ike
  • Patent number: 5151805
    Abstract: A driving method of a display apparatus for AC driving display materials such as liquid display and so on to the picture display by the use of an active matrix with switching elements of thin film transistors so that the output signal voltage of the signal driving circuit of the active matrix display apparatus is considerably reduced and the consumption power of the same driving circuit handling the analog signal may be reduced.
    Type: Grant
    Filed: November 26, 1990
    Date of Patent: September 29, 1992
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Etsuya Takeda, Yutaka Nanno, Seiichi Nagata
  • Patent number: 5151806
    Abstract: An active matrix-type liquid crystal display apparatus, in which a pixel electrode and a common electrode line are not overlapped but coupled capacitively by a floating electrode, so that the pixel electrode and common electrode do not short-circuit, and a storage capacitance is formed by the series connection of a plurality of capacitors. An active matrix-type liquid crystal display apparatus, in which a pixel electrode and a gate electrode line at the succeeding or preceeding row are not overlapped but coupled capacitively by a floating electrode, so that the pixel electrode and gate electrode do not short-circuit, and a storage capacitance is formed by the series connection of a plurality of capacitors.
    Type: Grant
    Filed: March 6, 1991
    Date of Patent: September 29, 1992
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Satoru Kawamoto, Noaki Nakagawa, Masahiro Hayama
  • Patent number: 5151614
    Abstract: A residual charge removing circuit connected to a node in a power-on reset pulse generating circuit for removing positive charges which remain in this node when a power supply is turned off is disclosed. This residual charge removing circuit is formed of two N-channel MOS transistors connected in series between the node and the ground, and one capacitor. Out of the two N-channel MOS transistors, the transistor near the node has a grounded gate. The capacitor is connected between a gate of the transistor, out of the two N-channel MOS transistors, which is distant from the node, and a power supply. The gate of the transistor distant from the node is connected to a connection point between the two N-channel MOS transistors. Therefore, when a supply potential lowers below a threshold voltage Vth of the MOS transistors due to the power-off, the transistor distant from the node is turned off, so that a potential of the connection point becomes -Vth owing to a discharge of negative charges from the capacitor.
    Type: Grant
    Filed: July 3, 1991
    Date of Patent: September 29, 1992
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Akira Yamazaki, Masaki Kumanoya, Yasuhiro Konishi, Katsumi Dosaka
  • Patent number: 5151808
    Abstract: A liquid crystal display comprises a pair of substrates provided with an electrode arrangement in matrix form. A chiral smectic C phase liquid crystal material is interposed between the substrates. In the liquid crystal layer, each pixel consists of a number of micro-domains which can be compared to polycrystalline structures. Interaction between adjacent pixels through well ordered liquid crystal structure is suppressed by virtue of the micro-domains.
    Type: Grant
    Filed: October 31, 1990
    Date of Patent: September 29, 1992
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Shunpei Yamazaki, Masahiko Sato