Field Period Polarity Reversal Patents (Class 345/79)
  • Patent number: 8384629
    Abstract: An offset voltage generating circuit sets an offset voltage through binary search based on a voltage value of the initial voltage, and a voltage controlling circuit generates an output voltage which is a predetermined gradation voltage added with the offset voltage, and applies a voltage based on the output voltage to a control terminal of a drive transistor. A current comparison circuit applies a supply voltage from a power supply to the other end of current path of the drive transistor. The current comparison circuit compares the current value of a reference current corresponding to the gradation voltage with a current value of the current flowing in the current path of the drive transistor at this time. The offset voltage generating circuit acquires a specific offset voltage corresponding to variation of the characteristic of the drive transistor based on a result of comparison performed by the current comparison circuit.
    Type: Grant
    Filed: June 28, 2010
    Date of Patent: February 26, 2013
    Assignee: Casio Computer Co., Ltd.
    Inventor: Satoru Shimoda
  • Patent number: 8373359
    Abstract: According to one embodiment, a light-emitting device includes an emitting layer, first and second electrodes, a voltage-supply circuit, an ammeter and a controller. The emitting layer includes a solution containing an emitting material and a solvent. The first and second electrodes are in contact with the solution. The voltage-supply circuit applies an operating voltage between the first and second electrodes. The ammeter measures the amount of electric current flowing between the first and second electrodes. The controller controls the operation of the voltage-supply circuit such that the polarity of the operating voltage reverses and determining a timing of reversing the polarity based on the output of the ammeter.
    Type: Grant
    Filed: March 16, 2011
    Date of Patent: February 12, 2013
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yukio Kizaki, Rei Hasegawa, Hajime Yamaguchi, Isao Amemiya
  • Patent number: 8334859
    Abstract: An electroluminescent (EL) display device has pixels spatially arranged in a matrix, each pixel having first, second, third and fourth EL elements, gate lines each coupled to a respective row of pixels, first data lines each coupled to the first EL elements of a respective column of pixels, second data lines each coupled to the second EL elements of a respective column of pixels, first switches each coupled to a respective third EL element, second switches each coupled to a respective fourth EL element, a switch control line coupled to the first and second switches for providing a switching control signal to set the first and second switches to be in an ON state or an OFF state, and third data lines each coupled to the first and second switches corresponding to a respective column of pixels for transmitting a data signal.
    Type: Grant
    Filed: March 28, 2011
    Date of Patent: December 18, 2012
    Assignee: Au Optronics Corporation
    Inventors: Chih-Chi Liu, Tze-Chien Tsai
  • Patent number: 8334822
    Abstract: Disclosed herein is a display apparatus, including: a pixel array section configured to have a plurality of pixels arranged in a matrix thereon, each of the pixels including an electro-optical element, a writing transistor, a driving transistor, and a storage capacitor connected between the gate electrode and the source electrode of the driving transistor for storing an image signal written by the writing transistor, each of the pixels carrying out a mobility correction process for applying negative feedback to a potential difference between the gate and the source of the driving transistor with a correction amount determined from current flowing to the driving transistor; a detection section configured to detect variation of a characteristic of any transistor in the pixels; and a control section configured to control the period of the mobility correction process based on a result of the detection by the detection section.
    Type: Grant
    Filed: May 28, 2009
    Date of Patent: December 18, 2012
    Assignee: Sony Corporation
    Inventors: Katsuhide Uchino, Tetsuo Minami
  • Publication number: 20120287099
    Abstract: A display device includes a plurality of pulse output circuits each of which outputs signals to one of the two kinds of scan lines and a plurality of inverted pulse output circuits each of which outputs, to the other of the two kinds of scan lines, inverted or substantially inverted signals of the signals output from the pulse output circuits. Each of the plurality of inverted pulse output circuits operates with at least two kinds of signals used for the operation of the plurality of pulse output circuits. Thus, through current generated in the inverted pulse output circuits can be reduced.
    Type: Application
    Filed: May 9, 2012
    Publication date: November 15, 2012
    Applicant: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
    Inventor: Kouhei Toyotaka
  • Patent number: 8310419
    Abstract: The present invention relates to a display device and a driving method thereof. The display device includes a light emitting device, a capacitor connected between a first electrical contact and a second electrical contact, a driving transistor, a switching transistor being controlled by a scanning signal to be connected between a data voltage and the first electrical contact, a first compensation transistor being controlled by a first compensation signal to be connected between the first electrical contact and a first voltage, and a second compensation transistor being controlled by a second compensation signal to be connected between the second electrical contact and a second voltage. The driving transistor includes an input terminal that is connected to a driving voltage, an output terminal that is connected to the second electrical contact, and a control terminal that is connected to the first electrical contact.
    Type: Grant
    Filed: December 26, 2008
    Date of Patent: November 13, 2012
    Assignee: Samsung Display Co., Ltd.
    Inventors: Doo-Hyung Woo, Kwang-Sub Shin, Young-Il Kim, Ji-Hye Eom
  • Patent number: 8300008
    Abstract: A method for operating an electrophoretic display apparatus including a first substrate; a second substrate; an electrophoretic device being held between the first substrate and the second substrate and containing electrophoretic particles; a first electrode formed on a surface of the first substrate, the surface facing the electrophoretic device; and a second electrode formed on a surface of the second substrate, the surface facing the electrophoretic device is provided. The method includes image displaying in which a voltage is applied to the electrophoretic device.
    Type: Grant
    Filed: September 17, 2009
    Date of Patent: October 30, 2012
    Assignee: Seiko Epson Corporation
    Inventor: Tsutomu Miyamoto
  • Patent number: 8294652
    Abstract: A driving method for driving an LCD panel having a counter electrode and a source line. In a first period, the counter electrode is driven to a potential VCOMH. In a second period, the counter electrode and the source line are short-circuited to a power supply interconnection having a power supply potential VCI. In a third period, the counter electrode is connected to a ground interconnection while the source line is kept to be short-circuited to the power supply interconnection. In a fourth period, the counter electrode is pulled down to a potential VCOML lower than a ground potential In a fifth period, the source line is driven to a potential corresponding to an image data while the counter electrode is kept to the potential VCOML. The electric power consumed in pulling down the counter electrode from a positive potential to a negative potential can be effectively reduced.
    Type: Grant
    Filed: October 30, 2008
    Date of Patent: October 23, 2012
    Assignee: Renesas Electronics Corporation
    Inventor: Hiroaki Shirai
  • Patent number: 8289244
    Abstract: A pixel circuit has a light emitting element and a driver electrically connected to the light emitting element. A reverse bias voltage is applied to the driver to reduce a shift amount of a threshold voltage of the driver.
    Type: Grant
    Filed: June 26, 2007
    Date of Patent: October 16, 2012
    Assignee: LG Display Co., Ltd.
    Inventors: Taro Hasumi, Yoshinao Kobayashi, Keigo Kanoh
  • Patent number: 8253663
    Abstract: A display apparatus and display driving method. A selective scan operation is performed on pixel circuits in row units, and a threshold-voltage correction operation is also performed to correct variations of the threshold voltage of respective pixel circuit driving transistors. Before performing the threshold-voltage correction operation in a horizontal scan period, a preparatory operation is performed in order to fix each of the electric potentials appearing on the gate and the source of the driving transistor at a predetermined level.
    Type: Grant
    Filed: March 19, 2008
    Date of Patent: August 28, 2012
    Assignee: Sony Corporation
    Inventors: Takayuki Taneda, Tetsuro Yamamoto, Yukihito Iida, Katsuhide Uchino
  • Patent number: 8243057
    Abstract: An organic electroluminescent display and driving method thereof. The organic electroluminescent display includes a demultiplexer for outputting signals provided by a data driver to a plurality of data lines according to on/off operation of analog switches. The driving method divides a frame into two parts, and drives them. Data signals are applied to pixels which are not adjacent among the pixels of each row during the former ½ frame, and the data signals are applied to the pixels to which no data signal has been applied in the former ½ frame during the latter ½ frame.
    Type: Grant
    Filed: April 7, 2004
    Date of Patent: August 14, 2012
    Assignee: Samsung Mobile Display Co., Ltd.
    Inventor: Dong-Yong Shin
  • Patent number: 8232932
    Abstract: The present invention suppresses the generation of a leak current that accompanies the polarity inversion of the voltage waveform of the opposing electrode. The display device that performs display by sequentially scanning a plurality of scan signal lines in a single cycle period comprises: a plurality of data signal lines that intersect the scan signal lines; a pixel electrode that is connected to the data signal lines; and an opposing electrode that is disposed opposite the pixel electrode and for which the polarity of an application voltage is inverted in each of the cycle periods. The cycle period includes a scan period in which one full scan of the scan signal lines is performed and a non-scan period in which the scan signal lines are not scanned.
    Type: Grant
    Filed: September 27, 2007
    Date of Patent: July 31, 2012
    Assignee: Citizen Holdings Co., Ltd.
    Inventors: Rintarou Takahashi, Takashi Akiyama
  • Patent number: 8232935
    Abstract: Disclosed herein is a display apparatus, including: a pixel array section including a plurality of pixels, a writing transistor, a driving transistor, a first switching transistor, a holding capacitor, and a second switching transistor; a first scanning section configured to drive the writing transistor in a unit of a row of the pixels; a second scanning section configured to drive the switching transistors in synchronism with scanning by the first scanning section; and a third scanning section configured to control the second switching transistors to a non-conducting state within a period after the image signal is written by the writing transistor until the signal writing period of the same row of the pixels ends but to a conducting state within any other period.
    Type: Grant
    Filed: May 21, 2008
    Date of Patent: July 31, 2012
    Assignee: Sony Corporation
    Inventors: Yutaka Mitomi, Masatsugu Tomida, Katsuhide Uchino
  • Patent number: 8207915
    Abstract: It is provided a display device that prevents, when applying a reverse bias, an anode line and a power supply line included in a signal line driver circuit from being short-circuited, and a driving method thereof. According to the invention, a reverse bias applying circuit is provided in a scan line driver circuit or a signal line driver circuit, a signal from the reverse bias applying circuit is supplied to a transistor disposed between a signal line and an anode line, and thereby the transistor is turned off. The reverse bias applying circuit comprises an analog switch or a clocked inverter and a biasing transistor, and drives so as to invert potentials of the anode line and a cathode line and apply a reverse bias to a light emitting element, while turn off the analog switch and turn on the biasing transistor. Then, a potential of the anode line becomes equal to that of a scan line, and thereby turning off the transistor between the anode line and the signal line assuredly.
    Type: Grant
    Filed: May 12, 2008
    Date of Patent: June 26, 2012
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Mitsuaki Osame, Aya Anzai, Tomoyuki Iwabuchi, Hideyuki Ebine
  • Patent number: 8199074
    Abstract: A representative system for displaying images comprises a pixel array, a conversion circuit, a memory device, and a compensation circuit. The pixel array has a plurality of pixels, each having at least one organic light emitting element equipped with a sensing unit which retrieves display information when the organic light emitting element retrieves a test signal. The conversion circuit determines a display parameter of each organic light emitting element according to the test signal and the display information of each organic light emitting element. The memory device stores the display parameter of each organic light emitting element. The compensation circuit modifies a video signal in accordance with the display parameters stored in the memory device.
    Type: Grant
    Filed: August 11, 2006
    Date of Patent: June 12, 2012
    Assignee: Chimei Innolux Corporation
    Inventors: Shou-Cheng Wang, Shih-Chang Chang
  • Patent number: 8193731
    Abstract: An LED lamp driven by alternating current includes at least a first constant-current supplying device, at least a second constant-current supplying device and at least an LED load. A terminal of the first constant-current supplying device is connected to the first connecting terminal of the AC power source. A terminal of the second constant-current supplying device is connected to the second connecting terminal of the AC power source. The LED load is connected between the first constant-current supplying device and the second constant-current supplying device in series. Through the current limiting function of the first constant-current supplying device and the second constant-current supplying device, the LED lamp may be protected.
    Type: Grant
    Filed: March 10, 2010
    Date of Patent: June 5, 2012
    Inventors: Ying-Chia Chen, Hui-Hua Lien
  • Patent number: 8164555
    Abstract: To provide a display device which can ensure high reliability of a driver circuit even when a threshold voltage of a TFT shifts. The display device includes a power supply control circuit which can apply a forward bias voltage or a reverse bias voltage to a gate of a transistor included in an output circuit, a monitor transistor which is formed to monitor the amount of change of a threshold voltage of the transistor included in the output circuit, and a threshold control circuit which controls the power supply control circuit so as to apply the reverse bias voltage to the gate of the transistor in order to compensate the threshold voltage of the transistor included in the output circuit.
    Type: Grant
    Filed: March 20, 2008
    Date of Patent: April 24, 2012
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Hiroyuki Miyake, Atsushi Umezaki
  • Patent number: 8120565
    Abstract: Display contrast in electro-optical display devices is improved using a drive circuit including pixel drive circuits and a common drive circuit. The pixel drive circuits are connected to pixel electrodes of the display device, and are operable to generate respective pixel drive signals that alternate between a first high voltage and a first low voltage differing in voltage by less than or equal to a process-limited maximum. The common drive circuit is connected to a common electrode of the display device, and is operable to generate a common drive signal alternating between a second high voltage and a second low voltage differing in voltage by more than the process-limited maximum. The common drive signal is asymmetrically bipolar with respect to the first low voltage of the pixel drive signal.
    Type: Grant
    Filed: February 4, 2004
    Date of Patent: February 21, 2012
    Assignee: Avago Technologies ECBU IP (Singapore) Pte. Ltd.
    Inventors: Ken A. Nishimura, Charles D. Hoke, Thomas A. Knotts
  • Patent number: 8115714
    Abstract: In one embodiment of the present invention, an active-matrix type display unit, and a drive method thereof are disclosed. Gate-bus lines are provided at both top and bottom sides of each row. Two sub-pixels are formed at a region surrounded by two adjacent source-bus lines and two adjacent gate-bus lines. At the odd-numbered rows, for the left-side sub-pixel of those two sub-pixels, a scanning signal is supplied from the top-side gate-bus line, while a video signal is supplied from the left-side source-bus line. For the right-side sub-pixel, on the contrary, a scanning signal is supplied from the bottom-side gate-bus line, while a video signal is supplied from the right-side source-bus line. At the even-numbered rows, the gate-bus line from which a scanning signal is supplied is reversed to the case of the odd-numbered rows. The gate-bus lines are sequentially selected one by one, and all the video signal polarities are made the same during each horizontal scanning period.
    Type: Grant
    Filed: January 28, 2008
    Date of Patent: February 14, 2012
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Atsuhito Murai, Kozo Takahashi
  • Patent number: 8094099
    Abstract: The present invention provides a display apparatus, including: a display section including a plurality of pixels disposed in a matrix and a plurality of signal lines and a plurality of scanning lines; and a horizontal driving circuit and a vertical driving circuit configured to drive the signal lines and the scanning lines of the display section to display an image on the display section; each of the pixels including a light emitting device; a signal level storage capacitor, a writing transistor, and a driving transistor.
    Type: Grant
    Filed: August 18, 2008
    Date of Patent: January 10, 2012
    Assignee: Sony Corporation
    Inventors: Katsuhide Uchino, Tetsuro Yamamoto
  • Patent number: 8044984
    Abstract: A method for driving an organic light emitting display (OLED) panel having a plurality of organic light emitting diodes is provided. The organic light emitting diodes are coupled to a plurality of segment lines and a plurality of common lines in a matrix structure. The organic light emitting diodes coupled to the same common lines are divided into a plurality of groups according to colors of the OLED panel. Driving currents are provided to the organic light emitting diodes of the groups according to a plurality of pulse width modulation (PWM) manners. The PWM manners generate waveforms having pulse width corresponding to grayscale in a period, wherein each PWM manner corresponds to different colors of the OLED panel.
    Type: Grant
    Filed: March 27, 2008
    Date of Patent: October 25, 2011
    Assignee: Himax Technologies Limited
    Inventors: Kuo-Tung Hsu, Wei-Jen Chang
  • Patent number: 8035584
    Abstract: An organic light emitting display and an image compensation method improves the Long Range Uniformity (LRU) of the output image by displaying the identical image when the identical image is input to each pixel, by measuring the luminance, chromaticity coordinates and color temperature after an organic light emitting display panel is fabricated, by storing the compensation values thereof in a memory in the form of a look-up table in advance, and by compensating one of a power supply voltage, a data voltage and a light emission time.
    Type: Grant
    Filed: April 23, 2007
    Date of Patent: October 11, 2011
    Assignee: Samsung Mobile Display Co., Ltd.
    Inventor: Jin-Woung Jung
  • Patent number: 8009125
    Abstract: In an organic electroluminescent (EL) display device, a main display panel and a sub display panel share a data line and a power supply voltage line. The organic EL display device has a top emission type main display panel and a bottom emission type sub display panel in a single display panel. The main display panel is composed of main pixels, each having a compensation circuit for compensating a threshold voltage, and the sub pixel display is composed of basic sub pixels without any compensation circuit. Each of the sub pixels has a boost capacitor which increases a data voltage, and which is disposed between a scan line and a storage capacitor so as to use the same voltage and power supply voltage as the main pixels. The sub pixels having the boost capacitor are disposed in the sub display panel, so that the main and sub display panels share the data line and the power supply voltage line.
    Type: Grant
    Filed: September 29, 2006
    Date of Patent: August 30, 2011
    Assignee: Samsung Mobile Display Co., Ltd.
    Inventor: Yang-Wan Kim
  • Patent number: 7973747
    Abstract: There is provided a display device: a display unit including a plurality of scan electrodes arranged to extend in parallel to each other along a first direction, a plurality of data electrodes arranged to extend in parallel to each other along a second direction crossing the scan electrodes, and a plurality of pixels, each pixel at which a pair of the scan electrode and the data electrode cross each other, each pixel having a light emitting layer and a dielectric layer interposed between the scan electrode and the data electrode from a direction vertical to a face; and an erasing pulse supplying unit operable to supply attenuation voltage pulse, to the light emitting layer of each pixel, which starts at a voltage not more than an emission starting voltage at which the light emitting layer starts emission and in which polarity is alternately reversed between positive and negative.
    Type: Grant
    Filed: October 25, 2005
    Date of Patent: July 5, 2011
    Assignee: Panasonic Corporation
    Inventors: Masayuki Ono, Shogo Nasu, Toshiyuki Aoyama, Masaru Odagiri
  • Patent number: 7956828
    Abstract: In an organic electroluminescence display device (30) comprising an organic EL element (26) having a structure wherein an organic luminescent medium (24) is sandwiched between a top electrode (20) and a bottom electrode (22), and a driving circuit (14) for driving the organic EL element (26), the organic luminescent medium (24) comprises a host compound and a triplet-related luminous compound and the driving circuit (14) applies a electric pulse voltage or pulse current having a frequency of 30 Hz or more and a duty ratio of 1/5 or less. In this way, it is possible to provide an organic EL display device which consumes a low electric power and has a long luminous life span, and a method for driving the same.
    Type: Grant
    Filed: January 6, 2006
    Date of Patent: June 7, 2011
    Assignee: Idemitsu Kosan Co., Ltd.
    Inventors: Masahide Matsuura, Chishio Hosokawa
  • Patent number: 7956824
    Abstract: A driver device for driving light emitting elements comprises a data latch having an input coupled to an input signal, a current control circuit having an input coupled to the data latch, and an output coupled to the input of an output stage, the latter being configured to drive the light emitting elements. The driver device has a power control circuit having an input coupled to the output of the data latch and an output coupled to the input of the current control circuit. The power control circuit is configured to control the current control circuit and the latter is configured to deliver a first current when the data inputted to the power control circuit is in a first state and a second current when at least part of the data inputted to the power control circuit is in a second state.
    Type: Grant
    Filed: July 26, 2007
    Date of Patent: June 7, 2011
    Assignee: STMicroelectronics S.r.l.
    Inventor: Nicola Li Volsi
  • Patent number: 7932876
    Abstract: An electro-optical device includes a plurality of pixel circuits each including a light-emitting element and a driving transistor for driving the light-emitting element; data lines that are connected to the plurality of pixel circuits and that supply data signals representing light-emitting gray-scale levels to the pixel circuits; and a data line driving circuit that supplies the data signals to the pixel circuits through the data lines. In addition, the data line driving circuit applies to each pixel circuit in a predetermined sequence a forward frame period supplying a data signal having a forward bias voltage for making the light-emitting element emit light and a backward frame period supplying a data signal having a backward bias voltage for making the light-emitting element not emit light, and drives each of the pixel circuits.
    Type: Grant
    Filed: July 6, 2005
    Date of Patent: April 26, 2011
    Assignee: Seiko Epson Corporation
    Inventors: Hiroaki Jo, Toshiyuki Kasai, Hiroshi Horiuchi, Takeshi Nozawa
  • Patent number: 7928948
    Abstract: The invention aims at preventing an occurrence of artefacts while reducing power consumption. A matrix addressing method for alternately driving pixels. The frame period of the images is formed by successively sequencing on a time series a plurality of block periods, the block periods each being composed of a first half block being a period for successively sequencing on a time series application timings of the pixel voltages for one or more row electrodes to be provided with one polarity, the second half block being a period for successively sequencing on a time series application timings of the pixel voltages for one or more row electrodes to be provided with the other polarity. Ones of even-numbered row electrodes and odd-numbered row electrodes in arrangement order on the display screen are selected in the first half block. The others spatially adjoining the ones are selected in the second half block.
    Type: Grant
    Filed: August 11, 2005
    Date of Patent: April 19, 2011
    Assignee: TPO Hong Kong Holdings Limited Corp.
    Inventors: Shuji Hagino, Hidetoshi Watanabe, Akihiro Iwatsu, Keitaro Yamashita
  • Patent number: 7847796
    Abstract: A display device includes a plurality of scanning lines, a plurality of data lines intersecting the scanning lines, a plurality of pixels each of which includes a switching transistor connected to a scanning line and a data line, a driving transistor connected to the switching transistor, and an emitting element connected to the driving transistor, wherein a data driver applies data voltages to the data line, and a scanning driver applies scanning signals each of which has at least three different voltage levels to the scanning line.
    Type: Grant
    Filed: November 16, 2006
    Date of Patent: December 7, 2010
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Kyoung-Ju Shin, Cheol-Woo Park, Sung-Jin Hong, Chong-Chul Chai
  • Patent number: 7800572
    Abstract: A liquid crystal display apparatus is composed of an LCD panel including data lines, and an LCD driver. The LCD driver includes: a positive drive circuit providing a positive data signal having positive polarity with respect to a ground level of the LCD driver for one of the data lines; and a negative drive circuit providing a negative data signal having negative polarity with respect to the ground level of the LCD driver for another one of the data lines.
    Type: Grant
    Filed: October 24, 2005
    Date of Patent: September 21, 2010
    Assignee: NEC Electronics Corporation
    Inventors: Masayuki Kumeta, Kouji Matsuura
  • Patent number: 7796108
    Abstract: A liquid crystal display device with no flicker and with bright excellent display is provided. A polarity pattern of a conventional frame inversion driving is one kind of display. A polarity pattern of a conventional source line inversion driving is two kinds of display, and a disclination pattern is one kind of display. On the contrary, in a circuit structure of the present invention, polarity patterns are made to have not less than four kinds, and disclination patterns are made to have not less than two kinds. By this, bright display in which flicker is not included and poor display due to disclination is improved, can be obtained.
    Type: Grant
    Filed: January 10, 2007
    Date of Patent: September 14, 2010
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventor: Yoshiharu Hirakata
  • Patent number: 7773056
    Abstract: A pixel circuit for a light emitting display. Adjacent pixels of the light emitting display coupled to one scan line share one first power supply line. A driving circuit in each pixel circuit drives first and second organic light emitting diodes (OLEDs). A switching circuit is coupled between the first and second OLEDs and the driving circuit to sequentially control the driving of the first and second OLEDs. Because two adjacent pixel circuits share one pixel power supply line and a plurality of OLEDs are coupled to one pixel circuit, it is possible to reduce the number of pixel circuits and the number of wiring lines of the light emitting display. Other circuit elements may also be shared between adjacent pixel circuits. Reducing the wiring and other elements of the pixel circuits makes it possible to increase the aperture ratio of the light emitting display.
    Type: Grant
    Filed: November 14, 2005
    Date of Patent: August 10, 2010
    Assignee: Samsung Mobile Display Co., Ltd.
    Inventors: Won Kyu Kwak, Sung Cheon Park
  • Patent number: 7688300
    Abstract: A driving method of a pixel array is provided. The driving method is suitable for a pixel array comprising at least one pixel set in each pixel array, wherein at least one pixel set comprises a plurality of pixels. In the driving method, a voltage having substantially same phase is used to drive the pixel electrodes of the pixels in the same pixel set. In addition, voltages with phases substantially opposite to each other are used to drive the pixel electrodes of the pixels in two adjacent pixel sets. Furthermore, a single gate line is used to drive two adjacent pixels in two different pixel sets respectively. In addition, a single gate line is used to drive a first pixel in one of the pixel set and another pixel in an adjacent column of the first pixel, wherein a phase of the voltage of a pixel electrode of the first pixel and a phase of a voltage of a pixel electrode of the other pixel are substantially different.
    Type: Grant
    Filed: May 24, 2004
    Date of Patent: March 30, 2010
    Assignee: Au Optronics Corporation
    Inventor: Kuo-Hsing Cheng
  • Patent number: 7671825
    Abstract: According to one aspect of the present invention, it is possible to sufficiently perform the discharging of charge without lowering the light emitting efficiency of an organic EL device and hence, the device can exhibit the light emitting efficiency higher than a conventional organic EL device and, at the same time, can prevent the degradation of the device. As an organic EL device to which the present invention is applied, on a glass transparent substrate, a transparent electrode, a hole injection layer and a hole transport layer which function as a hole transport function layer, a light emitting layer, an electron transport function layer, and a metal electrode are formed sequentially, and a drive power sources are connected to the transparent electrode and the metal electrode.
    Type: Grant
    Filed: February 24, 2006
    Date of Patent: March 2, 2010
    Assignee: Hitachi Displays, Ltd.
    Inventors: Norikazu Uchiyama, Masaaki Okunaka, Masahiro Nishizawa, Hidetsugu Matsukiyo, Yuko Matsumoto
  • Patent number: 7663581
    Abstract: A light emitting display increases the lifetime of a light emitting element by reverse biasing the light emitting element without using an additional power source and a power source line. The light emitting element is reverse biased without using the power source and the power source line for the reverse bias because a low level light emitting scan signal is used. The aperture ratio, contrast ratio, and lifetime of the light emitting display are increased.
    Type: Grant
    Filed: November 3, 2005
    Date of Patent: February 16, 2010
    Assignee: Samsung Mobile Display Co., Ltd.
    Inventor: Won-Kyu Kwak
  • Patent number: 7652432
    Abstract: An organic electro-luminescence (EL) device including at least an emission layer between an anode and a cathode that are opposed to each other, including an anode buffer layer that is composed of an electrically conductive material and is provided between the anode and the emission layer, a cathode buffer layer that is composed of an electrically conductive material and is provided between the cathode and the emission layer, and a drive unit that applies a forward bias voltage and a reverse bias voltage that have opposite polarities to the anode and the cathode with setting application time periods of the forward bias voltage and the reverse bias voltage according to a luminance ratio of an image to be displayed.
    Type: Grant
    Filed: February 15, 2006
    Date of Patent: January 26, 2010
    Assignee: Seiko Epson Corporation
    Inventors: Hiroyuki Hara, Rie Makiura
  • Patent number: 7652646
    Abstract: Systems for displaying images are provided.
    Type: Grant
    Filed: April 14, 2006
    Date of Patent: January 26, 2010
    Assignee: TPO Displays Corp.
    Inventor: Ching-Wei Lin
  • Patent number: 7649513
    Abstract: An Organic light emitting diode display device includes: a pixel array having a plurality of scan lines and a plurality of data lines that cross each other, a plurality of power voltage supply lines to which a high level power supply voltage is supplied and that are substantially parallel to the data lines, a plurality of reset lines substantially parallel to the scan lines, a plurality of organic light emitting diodes that emit light due to the high level power supply voltage from the power voltage supply line, and a plurality of organic light emitting diode drive circuits that drive the organic light emitting diode with data from the data line in response to a scan signal from the scan line and that is initialized in response to a reset signal from the reset line; a scan drive circuit that supplies the scan signal to the scan lines; a reset drive circuit that supplies the reset signal to the reset lines that initializes the organic light emitting diode drive circuit; and a data drive circuit that supplies t
    Type: Grant
    Filed: June 23, 2006
    Date of Patent: January 19, 2010
    Assignee: LG Display Co., Ltd
    Inventors: Kwon Shik Park, Soo Young Yoon, Min Doo Chun
  • Patent number: 7639217
    Abstract: Scan driving circuit having a number of stages coupled together in series and coupled with first and second lock signal input lines. Each of the stages receives a start signal or an output signal of a previous stage and includes a transfer unit, an inversion unit, and a buffer unit and produces the output signal. The output signal of each of the stages includes a low level signal, the low level signal of each stage is sequentially shifted by one half of the clock signal period with respect to the low level signal of a previous stage. The series of shifted low level signals form the scan signals output by the scan driving circuit for driving an organic light emitting display device.
    Type: Grant
    Filed: August 29, 2006
    Date of Patent: December 29, 2009
    Assignee: Samsung Mobile Display Co., Ltd.
    Inventor: Dong Yong Shin
  • Patent number: 7636073
    Abstract: An image display apparatus includes a light emitting element that emits light depending on an injected electric current; a driver that includes at least a first terminal and a second terminal, and controls the light emitting element based on a potential difference, applied between the first terminal and the second terminal, of a level higher than a predetermined threshold; a storage capacitor that serves to retain a potential on the first terminal of the driver; and a controller that changes the potential on the first terminal via the storage capacitor at writing of electric data current corresponding to a display in a black level.
    Type: Grant
    Filed: June 23, 2005
    Date of Patent: December 22, 2009
    Assignees: Kyocera Corporation, Chi Mei Optoelectronics Corp.
    Inventors: Shinya Ono, Yoshinao Kobayashi
  • Patent number: 7629955
    Abstract: An active matrix display apparatus includes an active matrix display panel comprising a plurality of pixels arranged in a matrix in a row direction and a column direction, each pixel being constituted by a plurality of subpixels; and a drive circuit for applying a voltage to each of the subpixels so that a polarity of the voltage is inverted at a predetermined period in each of a row direction and a column direction. The plurality of subpixels are arranged in the row direction at a period different from half of the predetermined period of polarity inversion of the voltage in the row direction, thus providing flicker-less color display device even when general driver ICs for dot inversion drive are used.
    Type: Grant
    Filed: December 13, 2005
    Date of Patent: December 8, 2009
    Assignee: Canon Kabushiki Kaisha
    Inventors: Yasufumi Asao, Hideo Mori, Yutaka Inaba
  • Patent number: 7619594
    Abstract: A display unit is provided. The display unit includes a light-emitting diode, a driving transistor, and a power supply system. The light-emitting diode comprises a cathode and an anode. The driving transistor comprises a source, a drain, and a gate, wherein the gate receives a first voltage, the drain is coupled to a second voltage via the light-emitting diode and the gate receives a third voltage. The power supply system is coupled to the drain of the driving transistor, providing the second voltage in response to the voltage of the drain of the driving transistor.
    Type: Grant
    Filed: October 11, 2005
    Date of Patent: November 17, 2009
    Assignee: AU Optronics Corp.
    Inventor: Shuo-Hsiu Hu
  • Patent number: 7616177
    Abstract: A pixel driving circuit with threshold voltage and EL power compensation. The pixel circuit includes a storage capacitor, a transferring circuit, a driving element, and a switching circuit. The transferring circuit transfers a data signal or a variable reference signal to a first node of the storage capacitor. The driving element has a first terminal coupled to a first fixed potential and a second terminal coupled to a second node of the storage capacitor. The switching circuit is coupled to a third terminal of the driving element and the second node of the storage capacitor. The switching circuit can be controlled to make the driving element diode-connected in one time period and allowing a driving current to be output to a display element in another time period.
    Type: Grant
    Filed: July 1, 2005
    Date of Patent: November 10, 2009
    Assignee: TPO Displays Corp.
    Inventors: Du-Zen Peng, Shih-Feng Huang
  • Patent number: 7616178
    Abstract: A driving device and driving method for a light emitting device, and a display panel and display having the driving device are provided. In a display device having a light emitting diode, first and second driving parts are connected to the light emitting diode. A first switching part applies a first data voltage having a first direction and a second data voltage having a second direction opposite the first direction to the first and second driving parts, respectively, during a first frame. A second switching part applies the second data voltage and the first data voltage to the first and second driving parts, respectively, during a second frame.
    Type: Grant
    Filed: May 14, 2005
    Date of Patent: November 10, 2009
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Bong-Hyun You, Min-Koo Han
  • Publication number: 20090213045
    Abstract: It is provided a display device that prevents, when applying a reverse bias, an anode line and a power supply line included in a signal line driver circuit from being short-circuited, and a driving method thereof. According to the invention, a reverse bias applying circuit is provided in a scan line driver circuit or a signal line driver circuit, a signal from the reverse bias applying circuit is supplied to a transistor disposed between a signal line and an anode line, and thereby the transistor is turned off. The reverse bias applying circuit comprises an analog switch or a clocked inverter and a biasing transistor, and drives so as to invert potentials of the anode line and a cathode line and apply a reverse bias to a light emitting element, while turn off the analog switch and turn on the biasing transistor. Then, a potential of the anode line becomes equal to that of a scan line, and thereby turning off the transistor between the anode line and the signal line assuredly.
    Type: Application
    Filed: May 12, 2008
    Publication date: August 27, 2009
    Applicant: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Mitsuaki Osame, Aya Anzai, Tomoyuki Iwabuchi, Hideyuki Ebine
  • Patent number: 7535440
    Abstract: A light emitting element, in which voltages having different polarities are applied alternately in order to prevent the accumulation of electric charge in an organic compound layer of the light emitting element, and in which light is always emitted, no matter whether a positive polarity voltage or a negative polarity voltage is applied, is provided. An opposing electrode is formed between a first electrode and a second electrode, and a first light emitting element having a compound layer that contains a first organic substance between the first electrode and the opposing electrode, and a second light emitting element having a compound layer that contains a second organic substance between the opposing electrode and the second electrode, are formed in the present invention.
    Type: Grant
    Filed: April 4, 2003
    Date of Patent: May 19, 2009
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Takeshi Nishi, Noriko Shibata
  • Patent number: 7515121
    Abstract: A display apparatus includes signal lines to each of which a current is supplied to obtain an arbitrary current value, optical elements each optical behaving in accordance with the current value of the current flowing via the signal line, and a stationary voltage supply circuit for supplying a stationary voltage for setting the current value of the current flowing through the signal line to be stationary through the signal line.
    Type: Grant
    Filed: June 11, 2003
    Date of Patent: April 7, 2009
    Assignee: Casio Computer Co., Ltd.
    Inventors: Kazuhito Sato, Hiroyasu Yamada
  • Publication number: 20090046043
    Abstract: There is provided a display device: a display unit including a plurality of scan electrodes arranged to extend in parallel to each other along a first direction, a plurality of data electrodes arranged to extend in parallel to each other along a second direction crossing the scan electrodes, and a plurality of pixels, each pixel at which a pair of the scan electrode and the data electrode cross each other, each pixel having a light emitting layer and a dielectric layer interposed between the scan electrode and the data electrode from a direction vertical to a face; and an erasing pulse supplying unit operable to supply attenuation voltage pulse, to the light emitting layer of each pixel, which starts at a voltage not more than an emission starting voltage at which the light emitting layer starts emission and in which polarity is alternately reversed between positive and negative.
    Type: Application
    Filed: October 25, 2005
    Publication date: February 19, 2009
    Inventors: Masayuki Ono, Shogo Nasu, Toshiyuki Aoyama, Masaru Odagiri
  • Patent number: 7489293
    Abstract: To effectively reduce or prevent the deterioration of display quality caused by the errors included in the current supplied to an electro-optical element a pixel circuit includes a capacitor C1, transistors T1 and T2 that constitute a current mirror, and an organic EL element OLED. When a first driving mode is set, the transistor T1 functions as a programming element that writes data in the capacitor C1 in accordance with data current Idata and the second transistor T2 functions as a driving element that generates driving current Ioled in accordance with data stored in the capacitor C1. When the second driving mode that is alternately switched to the first driving mode in a predetermined period is set, the transistor T2 functions as the programming element and the transistor T1 functions as the driving element.
    Type: Grant
    Filed: November 15, 2004
    Date of Patent: February 10, 2009
    Assignee: Seiko Epson Corporation
    Inventors: Katsunori Yamazaki, Shoichi Iino
  • Patent number: 7432886
    Abstract: An organic EL display device for compensating for a reduction of the voltage between the gate and source of a driving transistor occurring due to a voltage drop of the source voltage caused by the resistance component of a power source line, and a method for driving the organic EL display device. The organic EL display device has a data driver for receiving digital image data and applying the digital image data and a data voltage corresponding to the position of a pixel circuit. The data driver outputs different data voltages depending on the position of the pixel circuit even when the same digital image data are received. When the driving transistor is a P-type transistor, the data driver applies a higher data voltage to a pixel circuit that is closer to an external voltage source than that applied to a farther one even when the same digital data are received.
    Type: Grant
    Filed: March 18, 2003
    Date of Patent: October 7, 2008
    Assignee: Samsung SDI Co., Ltd.
    Inventors: June-Young Song, Kyoung-Soo Lee