Having Three Or More Voltage Levels Patents (Class 345/210)
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Patent number: 7342561Abstract: A drive control circuit supplies a gate voltage so that display quality is not degraded even in a case where a vertical scanning frequency or a horizontal scanning frequency is changed. The circuit includes a timing controller for detecting a change of a horizontal scanning frequency, a gate voltage generating circuit for generating two kinds of gate-on voltages Va and Vb (Va<Vb), and a switch for outputting one of the gate-on voltages Va and Vb from the gate voltage generating circuit in accordance with an output of the timing controller. The timing controller includes a counter for counting the number of clocks for one horizontal period, and a comparator for comparing a count result with a threshold value. When the horizontal scanning frequency is in a normal state, the low gate-on voltage Va is outputted, and when the horizontal scanning frequency exceeds a predetermined threshold value, that is, the count value falls below a threshold value, the high gate-on voltage Vb is outputted.Type: GrantFiled: June 24, 2003Date of Patent: March 11, 2008Assignee: Sharp Kabushiki KaishaInventors: Katsuyoshi Hiraki, Yasutake Furukoshi, Koichi Katagawa, Masanori Nishido, Tetsuya Kobayashi
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Patent number: 7336268Abstract: An exemplary point-to-point display system comprises a host system, a timing controller, and a display. The host system is configured to provide data for display. The timing controller is configurable to provide data swapping, bus swapping, bit swapping, and combinations thereof to provide arranged data in response to the provided data. The display is configured to display the arranged data.Type: GrantFiled: October 30, 2002Date of Patent: February 26, 2008Assignee: National Semiconductor CorporationInventors: Donald E. Camp, Mark D. Kuhns, Randy J. Dahl, Osama F. Alborno
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Patent number: 7333102Abstract: A digital input power rail receives an input voltage for a display. A voltage regulator regulates the input voltage to a start-up voltage during a start-up period. After the start-up period, the voltage regulator regulates the input voltage to a steady-state voltage. The steady-state voltage is lower than the start-up voltage.Type: GrantFiled: December 31, 2003Date of Patent: February 19, 2008Assignee: Intel CorporationInventor: Don J. Nguyen
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Publication number: 20080024478Abstract: Disclosed herein is a digital-to-analog converter. The digital-to-analog converter includes: a higher resistor string; a lower resistor string; an operational amplifier; a higher selector; a lower selector; a first switch; a higher capacitor; a second switch; a third switch; and a control circuit.Type: ApplicationFiled: July 24, 2007Publication date: January 31, 2008Applicant: Sony CorporationInventors: Masaki Yoshioka, Genichiro Oga, Ken Kitamura, Takaaki Sugiyama, Motoyasu Yano
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Patent number: 7324079Abstract: A gradation potential generating circuit in a color liquid crystal display device includes 65 resistance elements connected in series and dividing a voltage applied between first and second nodes to generate 64 gradation potentials; a first current amplifier circuit provided corresponding to each gradation potential higher than a precharge potential of a data line and having charging capability higher than discharging capability; and a second current amplifier circuit provided corresponding to each gradation potential lower than the precharge potential and having discharging capability higher than charging capability.Type: GrantFiled: November 20, 2002Date of Patent: January 29, 2008Assignee: Mitsubishi Denki Kabushiki KaishaInventor: Youichi Tobita
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Publication number: 20080018634Abstract: A liquid crystal display device and driving method thereof that are capable of generating positive and negative bias voltages the absolute values of which are symmetrical. The liquid crystal display device of the present invention includes a pulse generator for generating a pulse signal, a positive bias voltage generator for generating a positive bias voltage using (by rectifying) the pulse signal and a negative bias voltage generator for generating a negative bias voltage the absolute value of which is substantially symmetrical with the absolute value of the positive bias voltage. The pulse generator generates the pulse signal based on feedback of at least one of the positive and negative bias voltages.Type: ApplicationFiled: June 15, 2007Publication date: January 24, 2008Inventors: Sang Jae Yeo, Hyung Guel Kim, Se Chun Oh, Jong Won Moon
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Patent number: 7317455Abstract: A bias offset voltage circuit for controlling one or more devices is disclosed. The bias offset voltage circuit includes a three voltage sources connected in series and a switching element. Each voltage source includes a positive terminal and a negative terminal. The switching element includes a positive input terminal, a negative input terminal, and an output terminal. The negative terminal of the first voltage source is connected to the negative input terminal. The positive terminal of the third voltage source is connected to the positive input terminal. The terminals of the second voltage source are used to drive a first device. The output terminal of the switching element drives a second device. The bias offset voltage circuit may be used to provide proper voltages to each of the devices where the higher-supplied voltage could damage the device supplied with the lower supplied voltage, or vice versa.Type: GrantFiled: September 10, 2004Date of Patent: January 8, 2008Assignee: Xerox CorporationInventor: Charles A. Wright
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Patent number: 7280089Abstract: An apparatus and method for driving a field emission display (FED) device are disclosed. By applying a voltage to a specific electrode (data electrode or mesh electrode) of the FED device during a blanking time of a display frame of an FED, electric charges unnecessarily charged in the FED device can be removed.Type: GrantFiled: March 3, 2005Date of Patent: October 9, 2007Assignee: LG Electronics Inc.Inventor: Seong-Hak Moon
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Patent number: 7271800Abstract: A scan electrode drive of an apparatus for driving a plasma display panel includes a switching output circuit, a reset/sustain circuit, an upper scan circuit, a lower scan circuit, a first switching circuit, and a second switching circuit. The switching output circuit includes upper transistors, lower transistors each paired with corresponding upper transistor, and common output lines of the respective upper and lower transistor pairs, and the common output lines are connected to the scan electrode lines, respectively. The reset/sustain circuit outputs the driving signals during the reset period and the display-sustain period. The first switching circuit connects or disconnects the upper common power line of all of the upper transistors of the switching output circuit to or from an output terminal of the reset/sustain circuit.Type: GrantFiled: May 17, 2004Date of Patent: September 18, 2007Assignee: Samsung SDI Co., Ltd.Inventors: Hak-Ki Choi, Kyoung-Ho Kang, Seung-Hun Chae, Min-Sun Yoo, Woo-Joon Jeong
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Patent number: 7259755Abstract: A method and apparatus for driving a liquid crystal panel in a line-inversion system is disclosed. In the method, at least one pixel block each of which includes at least two data lines within the liquid crystal panel is set. The adjacent pixels in a gate line direction within the pixel block respond to data signals having the same polarity. The pixels within the other pixel areas except for the pixel block respond to data signals having a polarity contrary to the adjacent pixels at the left and right sides thereof. Accordingly, a current amount charged in the adjacent pixels having a large brightness difference is supplied always equally, so that the brightness difference between the adjacent pixels can be reduced to eliminate a noise pattern in the vertical direction.Type: GrantFiled: September 1, 2000Date of Patent: August 21, 2007Assignee: LG.Philips LCD Co., Ltd.Inventor: Seung Kuk Ahn
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Patent number: 7256777Abstract: This invention provides a method and an apparatus for saving power dissipation during the testing and evaluation of liquid crystal display LCD panels. In addition, this invention provides a method and apparatus of the changing of the order of backplane and segment addressing to reduce the power consumed by LCD panels. The method includes the step of interlacing the access of common or backplane addresses to an LCD. The LCD power saving method also includes the interlacing the access of the RAM data driving the LCD segment drivers. The segment address signals are developed from data read out of a random access memory, RAM. The segment address signals are activated such that alternating LCD panel locations are written with ones and zeros in a checkerboard pattern so as to stress the LCD panel in the worst case. This method provides for the saving of power dissipation during testing and evaluation by reducing the amount of segment switching from once every backplane cycle to once every frame.Type: GrantFiled: November 7, 2002Date of Patent: August 14, 2007Assignee: Dialog Semiconductor GmbHInventors: Kevin Jones, Julian Tyrrell
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Patent number: 7245295Abstract: A dynamic driving device is disclosed. The device enhances the display effect of a dynamic image on a liquid crystal display by dynamically adjusting the driving voltage applied to a liquid crystal display's Graphic Processing Unit (GPU) or Central Processing Unit (CPU). The device utilizes a driving path selection unit to allow a user to specify a driving path through an operation interface, which in turn affects the variation of driving voltage applied on the Graphic Processing Unit by dynamically adjusting the drive to the liquid crystal display.Type: GrantFiled: February 4, 2004Date of Patent: July 17, 2007Assignee: Vastview Technology Inc.Inventors: Cheng-Jung Chen, Jhih-Hong Jiang
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Patent number: 7239308Abstract: An image display apparatus includes scanning line control circuits for supplying a scanning voltage Vscan for selecting a plurality of electron sources in a unit of line to scan them in the vertical direction to the selected electron sources, a signal line control circuit for supplying a drive voltage Vdata based on an image signal to the electron sources of one line, and a signal processing circuit having a correction circuit, and the correction circuit corrects the image signal to add to the drive voltage Vdata an offset for compensating a voltage drop caused by an internal resistance R of a switch circuit in the scanning line control circuit, so that the voltage drop caused by the internal resistance of the switch circuit is compensated to lower or suppress reduction of brightness.Type: GrantFiled: August 30, 2004Date of Patent: July 3, 2007Assignee: Hitachi, Ltd.Inventors: Junichi Satoh, Fumio Haruna, Toshimitsu Watanabe, Yoshihisa Ooishi
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Patent number: 7221344Abstract: In a liquid crystal display device of an active matrix type, at first, an initialization signal voltage having a voltage value equal to or higher than the maximum voltage value of a display signal is applied to display pixels in a signal application period in a field period. The display signal is thereafter applied. As a result, the change amount of the voltage applied to liquid crystal due to the field-through voltage in relation to a gate pulse can be arranged to be substantially constant, and can always be cancelled by a common electrode voltage. Occurrence of flicker and seizure phenomena can be thereby restricted so that the display quality can be improved.Type: GrantFiled: November 7, 2001Date of Patent: May 22, 2007Assignee: Casio Computer Co., Ltd.Inventor: Shinichi Shimomaki
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Patent number: 7209129Abstract: A method and an apparatus for driving passive matrix liquid crystal, comprising the steps of: simultaneously selecting Y row electrodes, where Y is an odd number of 7 and above; calculating an exclusive OR between a Y-bit row selection vector representing a selection pattern of the Y row electrodes and Y-bit ON/OFF display data representing a display pattern of column electrodes, for each corresponding bit; adding the exclusive ORs for each bit; when X=(Y+1)/2, and a 1/(X?1) voltage of the maximum voltage of the column electrodes is Vc, selecting a voltage level of the column electrodes from X voltage levels satisfying:[2×i?(X?1)]×Vc (i=an integer of 0 to (X?1)) in accordance with the result of the addition for driving. These method and apparatus prevent the frame response phenomenon of high-speed liquid crystal while realizing high-contrast display, low-voltage driving, low power consumption, and reduction in chip size.Type: GrantFiled: June 13, 2002Date of Patent: April 24, 2007Assignee: Kawasaki Microelectronics, Inc.Inventors: Norimitsu Sako, Hideyuki Kitayama
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Patent number: 7199777Abstract: A liquid crystal display is provided, which includes: a liquid crystal panel including a gate line, a data line, and a pixel including a switching element connected to the gate line and the data line; a gate driver applying a gate signal for controlling the switching element to the gate line; and a data driver selecting gray voltages corresponding to gray signals and applying the selected gray voltages to the data line. The gate signal includes a gate-on voltage for turning on the switching element and a gate-off voltage for turning off the switching element. The gray voltages include pairs of positive and negative voltages (V+, V?) and V + + V - 2 = Vconst for each gray, where Vconst indicates a predetermined level.Type: GrantFiled: September 17, 2003Date of Patent: April 3, 2007Assignee: Samsung Electronics Co., LtdInventor: Seung-Hwan Moon
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Patent number: 7196680Abstract: The present invention provides a drive apparatus and method for a plasma display panel, in which the drive apparatus and method improve contrast and prevent mis-discharge. According to the drive method, in a reset interval of a first sub-field, a voltage having an increasing ramp waveform is applied to scan electrodes during a first interval, and common electrodes are floated during a portion of the first interval such that a voltage of the common electrodes is increased to an initial voltage, which corresponds to a voltage applied to the scan electrodes and to a voltage applied to both sides of panel capacitors.Type: GrantFiled: May 14, 2003Date of Patent: March 27, 2007Assignee: Samsung SDI Co., Ltd.Inventor: Jung-Pil Park
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Method and device for controlling a multiplexed display screen operating in reduced consumption mode
Patent number: 7180494Abstract: The present invention concerns a method and a device (30) for controlling a multiplexed display comprising a plurality of pixels arranged in lines and in columns and coupled to line electrodes and column electrodes, each of the pixels being selectively activated or deactivated by a determined combination of a line signal (BP1 to BP24) and of a column signal (FP1 to FP5) applied respectively across the corresponding line and column electrodes. According to the present invention, the display is switched between a first so-called normal operating mode, wherein all the display lines are activated, and at least a second so-called standby operating mode, wherein so-called non-active lines of the display are deactivated by applying, across the corresponding line electrodes, so-called non-activation line signals.Type: GrantFiled: March 15, 2001Date of Patent: February 20, 2007Assignee: EM Microelectronic-Marin SAInventors: Antonio Martino Ponzetta, Francisco Ramos, Sylvain Grosjean -
Patent number: 7176876Abstract: The present invention provides a bright and high-resolution display apparatus having a dynamic range exceeding the number of gray-scale voltage (or current) outputs, which a signal driver is capable of generating. In accordance with the present invention, a select period, in which a group of pixels on each row is driven, is divided into a plurality of sub-periods. The signal driver supplies a voltage output varying from sub-period to sub-period to selected pixels through a signal electrode. The pixel is capable of expressing various values of a gray scale, the size of which is at least approximately equal to (the number of gray-scale voltage outputs, which the signal driver is capable of generating)×(the number of sub-periods). By changing the ratio of the length of a sub-period to the length of another sub-period or the range of the driving voltage (or current), the dynamic range of the display can be further increased.Type: GrantFiled: July 31, 2003Date of Patent: February 13, 2007Assignee: Hitachi, Ltd.Inventors: Nobuaki Kabuto, Toshimitsu Watanabe, Yoshie Kodera, Mutsumi Suzuki, Tetsu Ohishi
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Patent number: 7173614Abstract: In the case of supplying voltage to a common electrode which faces a pixel electrode through electro-optical substance while changing the voltage from a first low-potential-side voltage to a first high-potential-side voltage, a second high-potential-side voltage, which is higher than the first high-potential-side voltage, is supplied to the common electrode instead of the first low-potential-side voltage, and the first high-potential-side voltage is then supplied to the common electrode. One of the first high-potential-side voltage and a first intermediate voltage, which is lower than the first high-potential-side voltage but higher than the first low-potential-side voltage, may be supplied to the common electrode before supplying the second high-potential-side voltage to the common electrode.Type: GrantFiled: July 15, 2004Date of Patent: February 6, 2007Assignee: Seiko Epson CorporationInventor: Akira Morita
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Patent number: 7167168Abstract: A display device comprising an electrode 12, an electrode 16 and a liquid crystal layer 18 which is formed between the electrode 12 and the electrode 16 and change a display state corresponding to a voltage applied between the electrode 12 and the electrode 16, the display device further comprises a piezoelectric element 24 for producing a drive voltage signal which abruptly increases up to a prescribed voltage value and then gradually attenuates, a phase difference generating circuit 26 which, from the drive voltage signal produced by the piezoelectric element 24, generates and outputs a first voltage signal and a second voltage signal having a phase difference from the first voltage signal. The first voltage signal is applied to the electrode 12, and the second voltage signal is applied to the electrode 16. Thus, the orientation state of the chiral nematic liquid crystal can be changed without using an expensive electric power source.Type: GrantFiled: April 20, 2004Date of Patent: January 23, 2007Assignee: Fujitsu LimitedInventors: Masaki Nose, Junji Tomita
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Patent number: 7145560Abstract: An apparatus is provided that includes circuitry (i.e. a central processing unit), a peripheral device (i.e. a liquid crystal display), and a thermal coupler. The peripheral device is substantially thermally insulated from the circuitry. The thermal coupler thermally couples the circuitry and the peripheral device. A method is also provided that includes a sensing step and a causing step. The sensing step includes sensing a temperature of a peripheral device (i.e. a liquid crystal display). The causing step includes causing power to be provided to the peripheral device according to the sensed temperature.Type: GrantFiled: January 13, 2003Date of Patent: December 5, 2006Assignee: LG Electronics Inc.Inventor: Jong Hyun Woo
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Patent number: 7142183Abstract: A dual input mode liquid crystal display having high resolution and employing dynamic capacitance compensation (“DCC”) is provided. The liquid crystal display includes a timing controller including a DCC processing unit for applying dynamic capacitance compensation (“DCC”) to a part of the pixels, a timing redistribution block for converting a format of the DCC-applied data to a predetermined format for a source driver, and a control signal generating block for generating a control signal for displaying an image. Since the DCC processing unit uses only two frame memories, the DCC may be employed by a dual input mode LCD. In addition, since a clock frequency for data processing in the frame memory of the timing controller is preferably the same as the clock frequency in the timing controller of the dual input mode LCD, thereby preventing the increase of EMI.Type: GrantFiled: November 19, 2002Date of Patent: November 28, 2006Assignee: Samsung Electronics Co., Ltd.Inventor: Seung-Woo Lee
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Patent number: 7119772Abstract: A gray scale bistable electro-optic display is driven by storing a look-up table containing data representing the impulses necessary for transitions, storing data representing at least an initial state of each pixel of the display, storing data representing temporal and gray level prior states of each pixel, receiving an input signal representing a desired final state of at least one pixel of the display; and generating an output signal representing the impulse necessary for a transition, as determined from the look-up table, dependent upon the temporal and gray level prior states. Other similar methods for driving such displays are also disclosed.Type: GrantFiled: March 31, 2004Date of Patent: October 10, 2006Assignee: E Ink CorporationInventors: Karl R. Amundson, Robert W. Zehner, Ara N. Knaian, Benjamin Zion
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Patent number: 7116318Abstract: A display pixel unit provides reduced capacitative coupling between a pixel electrode and a source line. The unit includes a transistor, the pixel electrode, and the source line. The source line includes an extension that provides a source for the transistor. A patterned conductive portion is disposed adjacent to the source line.Type: GrantFiled: April 24, 2003Date of Patent: October 3, 2006Assignee: E Ink CorporationInventors: Karl R. Amundson, Yu Chen, Kevin L. Denis, Paul S. Drzaic, Peter T. Kazlas, Andrew P. Ritenour
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Patent number: 7109983Abstract: In a period from temporal storage of a video signal to reading and displaying of the video signal, an average value 121 of the brightness levels obtained from a video signal before the video signal is stored in a storage means 3 and a predetermined target value 122 are used to perform a calculation by using a proportionality term and an integration term so that a quantity of limited electric currents is obtained. Moreover, the quantity of limited electric currents is provided with a non-response region or a hysteresis characteristic.Type: GrantFiled: June 26, 2003Date of Patent: September 19, 2006Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Yoshiki Ono, Jun Someya, Yoshiaki Okuno
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Patent number: 7109984Abstract: A liquid crystal display (“LCD”) having a plurality of gray voltages with varying magnitudes and a driving method thereof. An LCD includes a reference voltage generator changing level of a supply voltage based on a first signal to generate a reference voltage. The first signal varies depending on the surrounding brightness of the LCD, the brightness of the on-screen images of the LCD, and user's manipulation. The LCD also includes a gray voltage generator generating a plurality of gray voltages with magnitudes varying dependent on the magnitude of the reference voltage and a predetermined voltage such as a ground voltage. The LCD further includes a plurality of gate lines transmitting a plurality of gate signals, a plurality of data lines transmitting the gray voltages, and a plurality of pixels. Each pixel has a switching element connected to one of the gate lines and one of the data lines and transmitting the gray voltages to the pixels under the control of the gate signal.Type: GrantFiled: September 25, 2002Date of Patent: September 19, 2006Assignee: Samsung Electronics Co., Ltd.Inventor: Seung-Hwan Moon
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Patent number: 7102597Abstract: A device for driving capacitive light emitting elements includes a plurality of electrical charge recovery switches that send a current corresponding with an electrical charge, which has accumulated in a capacitor, individually to a plurality of drive electrodes connected to the respective capacitive light emitting elements. The electrical charge recovery switches also supply a current corresponding with the electrical charge that has accumulated in each of the capacitive light emitting elements to the capacitor individually via each of the drive electrodes. The driver device also includes a plurality of output buffers that apply a pixel-data-dependent voltage to the drive electrodes. It is determined, for each drive electrode, whether the voltage of the drive electrode has shifted from a high voltage to a low voltage or from a low voltage to a high voltage on the basis of the pixel data.Type: GrantFiled: October 13, 2004Date of Patent: September 5, 2006Assignee: Pioneer CorporationInventor: Takashi Iwami
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Patent number: 7091966Abstract: A plurality of pixel electrodes, TFTs to control the switching of the pixel electrodes, scan lines to supply scan lines to the gates of the TFTs, and data lines to supply image signals to the pixel electrodes via the TFTs when the TFTs are put into an ON state are provided on a substrate. A scan-signal supply circuit to line-sequentially supply the scan signals is further provided. The scan-signal supply circuit holds the scan signals to an intermediate potential for a predetermined period in the middle of changing the potential of the scan signals between a high potential that puts the TFTs into the ON state and a low potential that puts the TFTs into the OFF state.Type: GrantFiled: June 23, 2003Date of Patent: August 15, 2006Assignee: Seiko Epson CorporationInventors: Toru Aoki, Kenya Ishii
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Patent number: 7088349Abstract: A method of sub-field drive can display with a mode of placing emphasis on responsiveness and display with a mode of placing emphasis on gray-scale reproductiveness. A field is divided into plural sub-fields on a time axis, and each of such sub-fields is a control unit of driving a pixel. A code storing ROM stores a code that controls sub-fields to collecting on-voltage intensively in a former part of a field based on display data. Another code storing ROM stores a code that controls sub-fields to increase levels of gray scale based on display data. A data encoder determines whether each pixel of display data is an edge part of a moving image or not, selects a code that enables superior display in responsiveness at the edge part of a moving and selects a code that enables superior display in gray scale reproductiveness in other parts from the ROMs.Type: GrantFiled: November 20, 2002Date of Patent: August 8, 2006Assignee: Seiko Epson Corp.Inventor: Hidehito Iisaka
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Patent number: 7079127Abstract: A reference voltage generation circuit outputs multi-valued reference voltages by a ladder resistance circuit connected between a first power supply line to which a power supply voltage on the high potential side is supplied and a second power supply line to which a power supply voltage on the low potential side is supplied. The ladder resistance circuit is formed by connecting a plurality of resistance circuits in series. A first impedance variable circuit of the reference voltage generation circuit changes a first impedance value (resistance value) between the first power supply line and a jth (j is an integer) divided node. A second impedance variable circuit in the reference voltage generation circuit changes a second impedance value (resistance value) between the kth (1?j<k?i, k is an integer) divided node and the second power supply line.Type: GrantFiled: January 31, 2003Date of Patent: July 18, 2006Assignee: Seiko Epson CorporationInventor: Akira Morita
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Patent number: 7071929Abstract: In a method of driving an active matrix liquid crystal display according to pulse width modulation driving system using a thin-film transistor for a switching device, the variation of the temperature of a liquid crystal display panel is monitored. Particularly, the panel temperature detecting means of the liquid crystal display panel is provided, and gate-on voltage or data signal pulse width and a frequency of a reference clock signal are corrected according to the temperature of the panel. The corrected quantity of gate-on voltage according to the polarity of write data or the corrected quantity of data signal pulse width is determined according to the temperature of the panel. The higher the temperature of the panel is, to the lower value the positive or negative gate-one voltage is set and the lower the temperature of the panel is, to the higher value the positive or negative gate-on voltage is set. Positive gate-on voltage is set so that it is always higher than negative gate-on voltage.Type: GrantFiled: March 4, 2003Date of Patent: July 4, 2006Assignee: NEC CorporationInventor: Gen Fujii
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Patent number: 7064737Abstract: A method of driving a cholesteric liquid crystal display (LCD) panel by applying at least first, second, and third voltages to cholesteric liquid crystal cells of the cholesteric LCD panel is provided. The method includes alternately applying the first and second voltages to apply the third voltage, which is given by the root-mean-square value of the first and second voltages, to the cholesteric liquid crystal cells.Type: GrantFiled: October 18, 2002Date of Patent: June 20, 2006Assignee: Samsung SDI Co., Ltd.Inventors: Nam-Seok Lee, Woon-Seop Choi, Yeon-Gon Mo, Ki-Suk Seong, Seok-Hong Jeong
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Power supply circuit, operational amplifier circuit, liquid crystal device and electronic instrument
Patent number: 7061481Abstract: Disclosed are a power supply circuit which can cope with a multipotential level design and is suitable for generating potentials for driving a liquid crystal, and a liquid crystal device and an electronic instrument which use the power supply circuit. A first step-up circuit in the power supply circuit generates a first stepped-up potential level obtained by stepping up a power-supply level with a ground level taken as a reference. A regulator circuit generates a center potential obtained by regulating the first stepped-up potential level by referring to a reference potential level with the ground level taken as a reference. A second step-up circuit generates a second stepped-up potential level obtained by stepping up the center potential with the ground level taken as a reference.Type: GrantFiled: November 23, 2001Date of Patent: June 13, 2006Assignee: Seiko Epson CorporationInventor: Masahiko Tsuchiya -
Patent number: 7057597Abstract: An object of the invention is to improve the moving-picture quality of an active matrix type liquid crystal display apparatus. The apparatus comprises liquid crystal pixels disposed in a matrix configuration, a line drive circuit sequentially scanning each line of the pixels at every frame repeating with a predetermined frequency, and a column drive circuit writing an image signal into the pixels in sync with the sequential scanning. The frame is divided into a preceding and following sub-frame. The line drive circuit scans sequentially for the preceding and a following sub-frame. The column drive circuit writes an image signal originally assigned to a frame into the pixels for the preceding sub-frame, and then writes an image signal for adjusting the image quality into the pixels for the following sub-frame. The image signal for adjusting the image quality is obtained by operating the image signal assigned to the frame and an image signal assigned to the next frame.Type: GrantFiled: April 2, 2003Date of Patent: June 6, 2006Assignee: Sony CorporationInventor: Hiroyuki Ikeda
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Patent number: 7053891Abstract: An LCD with power conversion capability. The LCD implements a power conversion model inside to convert AC input into DC operating voltage for the LCD. The power conversion model can provide functionalities of output voltage adjustment, voltage overload protection, output short-circuited protection and optimized DC conversion efficiency, thereby achieving the desired reliability.Type: GrantFiled: November 18, 2002Date of Patent: May 30, 2006Assignee: Lite-On Technology Corp.Inventor: Yew-Peng Kee
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Patent number: 7050040Abstract: An electrophoretic display includes a cell having a viewed region and a non-viewed region. The cell contains a suspending fluid and a first particle species and a second particle species dispersed within the suspending fluid. Application of a first electrical field causes the first particle species and the second particle species to vibrate and separate from: one another, the cell walls, the viewed region, and the non-viewed region. Application of a second electric field, in one direction, causes the first particles to migrate toward the viewed region and the second particles to migrate toward the non-viewed region, effecting a color state. The electrophoretic display may be fabricated from multiple display cells arranged on a substrate.Type: GrantFiled: December 18, 2002Date of Patent: May 23, 2006Assignee: Xerox CorporationInventors: Jurgen H. Daniel, Robert A. Street
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Patent number: 7034798Abstract: A method of matrix-driving liquid crystal which exhibits a cholesteric phase and a liquid crystal display apparatus which is driven by the method. The method comprises a reset step Trs, a selection step Ts, an evolution step Trt and a display step Ti, and the selection step comprises a selection pulse application step Tsp, and a pre-selection step Tsz and a post-selection step Tsz? respectively before and after the selection pulse application step Tsp. The ratio of the length of the selection pulse application step Tsp to the length of the selection step Ts is changed with changes in temperature, and thereby, the temperature dependency of the responsibility of liquid crystal is compensated.Type: GrantFiled: January 23, 2002Date of Patent: April 25, 2006Assignee: Minolta Co., Ltd.Inventors: Naoki Masazumi, Shuji Yoneda
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Patent number: 7027020Abstract: A designing method and circuit of gray level and luminance characteristic of liquid crystal display are disclosed. A LCD is used to actually measure data about gray level and luminance of the liquid crystal display for building a gray level and luminance database of the liquid crystal display. The characteristic of gray level and luminance at other voltages is calculated to estimate a relation between gray level and luminance using a different driving circuit chip, thereby adjusting internal resistance of the driving circuit chip of the liquid crystal display to have optimal relation between gray level and luminance, and adjusting black signal high voltage, white signal high voltage, white signal low voltage and black signal low voltage to match the display data and generate outputs of a high voltage and a low voltage of each gray level.Type: GrantFiled: December 6, 2002Date of Patent: April 11, 2006Assignee: Chunghwa Picture Tubes, LtdInventor: Shih-Hsiung Huang
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Patent number: 7019735Abstract: In a flat panel display device in which driving circuits and the like are arranged on an array substrate, a technology to realize a compact size and a low cost of an external control circuit is disclosed. At least one pumping circuit included in the external control circuit is arranged on the array substrate, and an output side capacitor connected between an output portion of the pumping circuit and the ground GND and an input side capacitor of a clock input portion are arranged outside the array substrate.Type: GrantFiled: July 16, 2003Date of Patent: March 28, 2006Assignee: Kabushiki Kaisha ToshibaInventors: Yasushi Sasaki, Masaki Miyatake, Hajime Sato, Takanori Tsunashima, Yasuyuki Hanazawa, Hoko Hirai
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Patent number: 7012600Abstract: A bistable electro-optic display has a plurality of pixels, each of which is capable of displaying at least three gray levels. The display is driven by a method comprising: storing a look-up table containing data representing the impulses necessary to convert an initial gray level to a final gray level; storing data representing at least an initial state of each pixel of the display; receiving an input signal representing a desired final state of at least one pixel of the display; and generating an output signal representing the impulse necessary to convert the initial state of said one pixel to the desired final state thereof, as determined from said look-up table. The invention also provides a method for reducing the remnant voltage of an electro-optic display.Type: GrantFiled: November 20, 2002Date of Patent: March 14, 2006Assignee: E Ink CorporationInventors: Robert W. Zehner, Holly G. Gates, Karl R. Amundson, Joanna F. Au, Ara N. Knalan, Jonathan L. Zalesky, Alexi C. Arango
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Patent number: 7012586Abstract: The present invention provides an image display device that reduces variations in brightness of the light emitting elements included in the device due to a voltage drop on the power source line of the device and TFT threshold voltage variations and displays good quality images. The image display device is equipped with a pixel circuit voltage detecting means to selectively output a voltage internal to a pixel circuit included in each of a plurality of pixels of the device to a signal line to which the pixel circuit connects. Its drive circuit is equipped with a voltage addition means to add the signal line voltage and a signal voltage corresponding to image data to be displayed and output a sum voltage to the signal line again.Type: GrantFiled: February 11, 2004Date of Patent: March 14, 2006Assignees: Hitachi, Ltd., Hitachi Displays, Ltd.Inventors: Hiroshi Kageyama, Hajime Akimoto
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Patent number: 6995754Abstract: A plasma display panel, driving circuits for driving the plasma display panel, and a power circuit into which an external alternating current is inputted are provided to a plasma display module. The power circuit supplies driving voltages to the driving circuits. The power circuit outputs an external source voltage to be used by an external power circuit and a control voltage for controlling operations of an interface board to which source voltages of the interface board are supplied from the external power circuit. Furthermore, operations of the power circuit are controlled with control signals output by the interface board.Type: GrantFiled: November 8, 2001Date of Patent: February 7, 2006Assignee: Pioneer CorporationInventors: Hiroshi Suetsugu, Taku Ohzono
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Patent number: 6987510Abstract: It is an object of the present invention to provide a display panel driver with which power consumption can be reduced. The display panel driver includes a pixel data pulse generation circuit which generates pixel data pulses by connecting the column electrodes and a power source line in accordance with the pixel data to apply the pixel data pulses to the column electrodes, and a resonance pulse power circuit which generates a resonance pulse power source voltage to apply the resonance pulse power source voltage to the power source line, the resonance pulse power circuit changing the resonance amplitude of the resonance pulse power source voltage while keeping a maximum voltage of the resonance pulse power source voltage in accordance with a pattern of a pulse sequence of the pixel data pulses.Type: GrantFiled: June 26, 2003Date of Patent: January 17, 2006Assignees: Pioneer Corporation, Pioneer Display Products CorporationInventors: Takashi Iwami, Toyohisa Yuasa, Takashi Okushima, Tetsuya Shigeta, Tetsuro Nagakubo
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Patent number: 6975313Abstract: The invention prevents or substantially prevents the brightness from changing according to the number of pixels that are turned on in a display. A power supply circuit calculates the total number of pixels that are turned on using ON/OFF data RD that stipulates the ON/OFF state of the pixels 1400 and controls the output impedance of a power supply voltage that is transmitted to a display panel, so that the output impedance becomes lower as the calculated total number of the pixels increases.Type: GrantFiled: December 9, 2002Date of Patent: December 13, 2005Assignee: Seiko Epson CorporationInventor: Takashi Kurumisawa
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Patent number: 6961041Abstract: A liquid crystal display device has a liquid crystal composition sandwiched between a pair of substrates, and a plurality of pixels disposed on one of the first substrates. Each of the pixels is supplied with a video signal via a switching element connected to a first electrode thereof, and is provided with a capacitance. One of two capacitance-forming electrodes forming the capacitance is connected to the first electrode of a corresponding one of the pixels, and another of the two capacitance-forming electrodes is supplied with a pixel-potential control signal. Polarity of the video signal reverses with respect to a first reference voltage with a repetition period, and the pixel-potential control signal alternates between two voltage levels of same polarity with respect to a second reference voltage such that a voltage swing on the first electrodes of the pixels becomes larger than that of the video signal.Type: GrantFiled: March 15, 2002Date of Patent: November 1, 2005Assignees: Hitachi, Ltd., Hitachi Device Engineering Co., Ltd.Inventors: Haruhisa Ilda, Iwao Takemoto, Katsumi Matsumoto, Shigeo Adachi
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Patent number: 6954195Abstract: A display device which has a liquid crystal display which has a plurality liquid crystal pixels arranged in a matrix and which writes an image thereon after resetting the liquid crystal. The method of writing on the liquid crystal display can be selected from driving methods according to interlace scanning in which a frame is divided into a plurality of fields and writing by interlace scanning is performed and driving methods according to sequential scanning in which scanning lines are subjected to writing serially. When high-speed writing is required, for example, when display of a motion picture, display of inputted letters or scroll display is desired, one of the driving methods according to interlace scanning is selected. In interlace scanning, based on the end of a blackout state of a scanning line in a field, selection of a scanning line in the next field for writing is started.Type: GrantFiled: February 28, 2001Date of Patent: October 11, 2005Assignee: Minolta Co., Ltd.Inventors: Shuji Yoneda, Masaaki Nakai, Eiji Yamakawa, Kiyofumi Hashimoto, Naoki Masazumi, Katsuhiko Asai, Koichi Kohriyama, Keizou Ochi, Takashi Kondo, Hideo Hotomi, Kazuaki Okumura, Makiko Mandai
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Patent number: 6950096Abstract: The present invention discloses a driver for amplifying an operating voltage of a low driving-voltage luminary. The driver includes a driving circuit providing a first signal, and a negative multiple voltage circuit electrically connected to the driving circuit and the luminary respectively for transforming the first signal into a second signal to be transmitted to the luminary, thereby the luminary being driven in response to the second signal. The luminary circuit is connected between power source (Vdd) and the negative multiple voltage circuit.Type: GrantFiled: August 19, 2002Date of Patent: September 27, 2005Assignee: Precision Instrument Development Center National Science CouncilInventors: Tai-Shan Liao, Min-Li Chen
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Patent number: 6927765Abstract: A display device which has a liquid crystal display having a liquid crystal material, a driver for driving the liquid crystal display, and a controller for controlling the driver to drive at least a part of the liquid crystal display by selectively using one of a first drive method and a second drive method which are different from each other in operational principle of the liquid crystal material. The pulse voltage to drive at least one pixel of the liquid crystal display can be selectively set to any one of a plurality of kinds. The data pulse voltage applied to a data electrode can be selectively set to any one of a plurality of kinds to drive at least one pixel of the liquid crystal.Type: GrantFiled: November 12, 1999Date of Patent: August 9, 2005Assignee: Minolta Co., Ltd.Inventors: Naoki Masazumi, Eiji Yamakawa, Hideo Hotomi
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Patent number: 6885365Abstract: A glass touch sensing circuit which is capable of accurately detecting a sense signal resulting from a user's touch under no influence of variations in temperature. The glass touch sensing circuit is adapted to compare the level of an output signal from a switching device, which indicates whether the user touches a touch sensor, with that of a reference signal and convert the output signal from the switching device into a wave-shaped signal in accordance with the compared result. The present glass touch sensing circuit is further adapted to determine the level of the reference signal for compensation for a variation in the output signal from the switching device with temperature. Therefore, the glass touch sensing circuit can be employed in a human body touch-based key input sensing system to provide a constant performance irrespective of a variation in temperature so as to sense a key input based on a touching operation.Type: GrantFiled: November 3, 2000Date of Patent: April 26, 2005Assignee: LG Electronics Inc.Inventor: Sang-Seog Kang