Patents by Inventor Junichi Yamashita

Junichi Yamashita has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 8902134
    Abstract: The invention provides a pixel circuit that can cancel the influence of the mobility of a drive transistor. A drive transistor supplies a light-emitting element with an output current dependent upon an input voltage. The light-emitting element emits light with a luminance dependent upon a video signal in response to the output current supplied from the drive transistor. The pixel circuit includes a correction unit that corrects the input voltage held by a capacitive part in order to cancel the dependence of the output current on the carrier mobility.
    Type: Grant
    Filed: April 8, 2011
    Date of Patent: December 2, 2014
    Assignee: Sony Corporation
    Inventors: Junichi Yamashita, Katsuhide Uchino
  • Publication number: 20140347338
    Abstract: The invention provides a pixel circuit that can cancel the influence of the mobility of a drive transistor. A drive transistor supplies a light-emitting element with an output current dependent upon an input voltage. The light-emitting element emits light with a luminance dependent upon a video signal in response to the output current supplied from the drive transistor. The pixel circuit includes a correction unit that corrects the input voltage held by a capacitive part in order to cancel the dependence of the output current on the carrier mobility.
    Type: Application
    Filed: August 14, 2014
    Publication date: November 27, 2014
    Inventors: Junichi Yamashita, Katsuhide Uchino
  • Publication number: 20140347337
    Abstract: A transistor connected to a power source for driving a light-emitting element driving transistor and a transistor setting to a predetermined voltage a source voltage of the light-emitting element driving transistor are commonly controlled by a control signal that takes one of three levels.
    Type: Application
    Filed: August 14, 2014
    Publication date: November 27, 2014
    Inventors: Katsuhide Uchino, Tetsuro Yamamoto, Junichi Yamashita
  • Patent number: 8896503
    Abstract: The present invention sets power supply drive signals DS[1] and DS[2] at a power supply voltage Vcc in a timesharing for odd lines and their subsequent even lines and sets a write signal WS to correspond to the time division setting, thereby sharing a scan line of the write signal WS between the odd lines and the subsequent even lines.
    Type: Grant
    Filed: July 27, 2009
    Date of Patent: November 25, 2014
    Assignee: Sony Corporation
    Inventors: Tomoaki Handa, Junichi Yamashita, Katsuhide Uchino
  • Publication number: 20140340289
    Abstract: A display device including: a plurality of sub-pixels arranged in a matrix, each including an electro-optical element having a structure in which a display functional layer is sandwiched between an upper electrode and a lower electrode; and an auxiliary interconnect contact in a pixel area in which the plurality of sub-pixels are arranged in a matrix and electrically connecting the upper electrode to an auxiliary interconnect, wherein m (m is an integer equal to or larger than two) sub-pixels adjacent to each other along an arrangement direction of the sub-pixels are regarded as one group, and n (n is a natural number smaller than m) auxiliary interconnect contacts are formed for each group.
    Type: Application
    Filed: August 4, 2014
    Publication date: November 20, 2014
    Inventors: Junichi Yamashita, Katsuhide Uchino
  • Publication number: 20140340288
    Abstract: A display device includes: a pixel array unit with pixel circuits disposed in matrix form, the pixel circuit including a driving transistor, an electro-optic element, a storage-capacitor, and a sampling transistor, with the electro-optic element emitting light by generating a driving current based on information stored in the storage-capacitor at the driving transistor to be applied to the electro-optic element; and a control unit, of which the output stage includes a buffer transistor, to output a pulse signal for driving the pixel array unit from the buffer transistor; wherein the pixel array unit and the control unit are formed with long laser beam irradiation to be scanned in the vertical direction; and with the control unit, buffer transistors for outputting a pulse signal for sampling to an input video signal to each signal line are arrayed in a column in the longitudinal direction of the laser beam irradiation.
    Type: Application
    Filed: July 30, 2014
    Publication date: November 20, 2014
    Inventors: Junichi Yamashita, Katsuhide Uchino
  • Patent number: 8890782
    Abstract: A drive section sequentially supplies respective scanning lines with a control signal and supplies respective signal lines with a video signal to carry out a correction operation for holding a voltage equivalent to a threshold voltage of a drive transistor in a holding capacitance, and subsequently performs a write operation for writing the video signal in the holding capacitance, and before the correction operation, the drive section switches potentials at the bias line and adds a coupling voltage to one current terminal of the drive transistor via an auxiliary capacitance to carry out a preparation operation for an initialization to set a potential difference between a control terminal and the one current terminal of the drive transistor larger than the threshold voltage.
    Type: Grant
    Filed: August 14, 2013
    Date of Patent: November 18, 2014
    Assignee: Sony Corporation
    Inventors: Junichi Yamashita, Katsuhide Uchino
  • Publication number: 20140333212
    Abstract: A pixel circuit able to prevent a spread of the terminal voltages of drive transistors inside a panel and in turn able to reliably prevent deterioration of uniformity, wherein a source of a TFT serving as a drive transistor is connected to an anode of a light emitting element, a drain is connected to a power source potential, a capacitor is connected between a gate and source of the TFT, and a source potential of the TFT is connected to a fixed potential through a TFT serving as a switch transistor and wherein pixel circuit lines are connected by an upper line and bottom line and are arranged in parallel with pixel circuit power source voltage lines so as not to have intersecting parts.
    Type: Application
    Filed: July 29, 2014
    Publication date: November 13, 2014
    Applicant: SONY CORPORATION
    Inventors: Katsuhide UCHINO, Junichi Yamashita, Tetsuro Yamamoto
  • Publication number: 20140333604
    Abstract: A display unit (1) includes a light-emitting device (13) and a pixel circuit (12) in each pixel (11), and a drive section (20) configured to drive the pixel circuit (12). The pixel circuit (12) includes a drive transistor (Tr1) configured to drive the light-emitting device (13), and a write transistor (Tr2) configured to control application of a signal voltage corresponding to an image signal to a gate of the drive transistor (Tr1). The drive section (20) performs Vth correction that allows a gate-source voltage of the drive transistor (Tr1) to be brought close to a threshold voltage of the drive transistor (Tr1) on all pixel rows, and then performs writing of the signal voltage corresponding to the image signal to gates of the drive transistors (Tr1) in all pixel rows.
    Type: Application
    Filed: November 19, 2012
    Publication date: November 13, 2014
    Applicant: Sony Corporation
    Inventors: Keisuke Omoto, Junichi Yamashita, Naobumi Toyomura
  • Patent number: 8884851
    Abstract: In a display apparatus including a switching transistor, a correction voltage for eliminating an effect of a variation in a characteristic of a driving transistor is stored in a storage capacitor. The switching transistor is disposed between one current terminal of the driving transistor and a light emitting element. The switching transistor turns off during the non-light emission period thereby to electrically disconnect the light emitting element from the one current terminal of the driving transistor thereby preventing a leakage current from flowing through the light emitting element during the period in which the correction unit operates, and thus preventing the correction voltage from having an error due to the leakage current.
    Type: Grant
    Filed: February 27, 2014
    Date of Patent: November 11, 2014
    Assignee: Sony Corporation
    Inventors: Junichi Yamashita, Masatsugu Tomida, Katsuhide Uchino
  • Patent number: 8884993
    Abstract: Disclosed herein is a signal processing apparatus, including: a luminance degradation information production section adapted to produce luminance degradation information regarding degradation of a luminance in accordance with a temperature condition upon emission; a luminance degradation value calculation section adapted to calculate a luminance degradation value regarding degradation of the luminance for each pixel circuit; and a correction section adapted to correct the gradation value of an image signal to be inputted to the pixel circuit based on the luminance degradation value.
    Type: Grant
    Filed: March 21, 2011
    Date of Patent: November 11, 2014
    Assignee: Sony Corporation
    Inventors: Junichi Yamashita, Hiroshi Hasegawa, Kazuo Nakamura, Tetsuro Yamamoto, Katsuhide Uchino
  • Patent number: 8884850
    Abstract: Disclosed herein is a display apparatus including a pixel array and a driver, the pixel array including rows of scanning lines, rows of feeding lines, columns of signal lines, and a matrix of pixels disposed at the crossings of the scanning lines and the signal lines, the driver including a write scanner for supplying a control signal successively to the scanning lines, a power supply scanner for switching each of the feeding lines between a high potential, a low potential, and an intermediate potential between the high potential and the low potential, and a signal selector for supplying a video signal, which alternately switches between a signal potential and a reference potential, to each of the signal lines.
    Type: Grant
    Filed: January 16, 2014
    Date of Patent: November 11, 2014
    Assignee: Sony Corporation
    Inventors: Junichi Yamashita, Katsuhide Uchino
  • Publication number: 20140327009
    Abstract: A display includes a pixel array part with pixels that each have at least one transistor whose conduction state is controlled by a drive signal input to a control terminal, and a scanner including a plurality of buffers that are formed of transistors. The buffers correspond to a pixel arrangement and output a drive signal to the control terminals of the transistors of the pixels. The transistors of the pixels and the transistors of the buffers are formed through irradiation with laser light that is moved for scanning in a predetermined direction and has a predetermined wavelength. The transistors in the buffers are formed in such a way that the channel length direction of the transistors is set parallel to the scan direction of the laser light.
    Type: Application
    Filed: July 21, 2014
    Publication date: November 6, 2014
    Inventors: Tetsuo Minami, Junichi Yamashita, Katsuhide Uchino
  • Publication number: 20140327665
    Abstract: A pixel circuit, display device, and method of driving a pixel circuit enabling source-follower output with no deterioration of luminance even with a change of the current-voltage characteristic of the light emitting element along with elapse, enabling a source-follower circuit of n-channel transistors, and able to use an n-channel transistor as an EL drive transistor while using current anode-cathode electrodes, wherein a source of a TFT 111 as a drive transistor is connected to an anode of a light emitting element 114, a drain is connected to a power source potential VCC, a capacitor C111 is connected between a gate and source of the TFT 111, and a source potential of the TFT 111 is connected to a fixed potential through a TFT 113 as a switching transistor.
    Type: Application
    Filed: July 15, 2014
    Publication date: November 6, 2014
    Applicant: Sony Corporation
    Inventors: Katsuhide UCHINO, Junichi YAMASHITA, Tetsuro YAMAMOTO
  • Patent number: 8878753
    Abstract: A display apparatus includes: a display panel that includes display elements having a current-driven light-emitting portion and that displays an image on the basis of a video signal; and a luminance correcting unit that corrects the luminance of the display elements when the display panel displays an image by correcting a gradation value of an input signal and outputting the corrected input signal as the video signal. The luminance correcting unit includes an operating time conversion factor holder, a reference operating time calculator, an accumulated reference operating time storage, a reference curve storage, a gradation correction value holder, and a video signal generator.
    Type: Grant
    Filed: November 22, 2011
    Date of Patent: November 4, 2014
    Assignee: Sony Corporation
    Inventors: Junichi Yamashita, Katsuhide Uchino
  • Publication number: 20140320472
    Abstract: A display apparatus includes a pixel array section and a driving section configured to drive the pixel array section. The pixel array section includes a plurality of first scanning lines and a plurality of second scanning lines extending along rows, a plurality of signal lines extending along columns, a plurality of pixels arranged in a matrix at positions at which the first and second scanning lines and the signal lines intersect with each other, and a plurality of power supply lines and a plurality of ground lines configured to perform feeding to the pixels. The driving section includes a first scanner, a second scanner, and a signal selector. Each of the pixels includes a light emitting element, a sampling transistor, a drive transistor, a switching transistor, and a pixel capacitance.
    Type: Application
    Filed: July 11, 2014
    Publication date: October 30, 2014
    Inventors: Katsuhide Uchino, Junichi Yamashita, Naobumi Toyomura
  • Patent number: 8872740
    Abstract: A display apparatus includes: a display panel that includes display elements having a current-driven light-emitting portion, in which the display elements are arranged in a two-dimensional matrix in a first direction and a second direction, and that displays an image on the basis of a video signal; and a luminance correcting unit that corrects the luminance of the display elements when displaying an image on the display panel by correcting a gradation value of an input signal and outputting the corrected input signal as the video signal. The luminance correcting unit includes a reference operating time calculator, an accumulated reference operating time storage, a reference curve storage, a gradation correction value holder, and a video signal generator.
    Type: Grant
    Filed: November 22, 2011
    Date of Patent: October 28, 2014
    Assignee: Sony Corporation
    Inventors: Junichi Yamashita, Katsuhide Uchino
  • Patent number: 8872867
    Abstract: A signal processing device measures an actual luminance of a light-emitting device by setting levels of gradation values indicating the degree of light emission to a pixel circuit having the light-emitting device to generate measurement information. The device also calculates gradation deterioration characteristics based on the measurement information and the relationship between a gradation value and a luminance value when the pixel circuit is in a correction reference state. A deterioration value calculation calculates a conversion efficiency deterioration value of conversion efficiency for the light-emitting device to convert a driving current supplied for a gradation value into a luminance to generate conversion efficiency deterioration characteristic information.
    Type: Grant
    Filed: December 12, 2011
    Date of Patent: October 28, 2014
    Assignee: Sony Corporation
    Inventors: Junichi Yamashita, Katsuhide Uchino
  • Patent number: 8847935
    Abstract: A display device includes: a screen unit; a drive unit; a signal processing unit; and a selector, wherein the screen unit includes rows of scanning lines, columns of signal lines, matrix-state pixel circuits and a light sensor, the drive unit includes a scanner supplying a control signal to the scanning lines and a driver supplying a video signal to the signal lines, the screen unit is sectioned into plural regions each having plural pixel circuits, the pixel circuit emits light in accordance with the video signal, the light sensor is arranged with respect to each region and outputs a luminance signal in accordance with the light emission, the selector supplies plural luminance signals to the signal processing unit by switching the signals, and the signal processing unit corrects the video signal in accordance with the luminance signals and supplies the video signal to the driver.
    Type: Grant
    Filed: October 19, 2009
    Date of Patent: September 30, 2014
    Assignee: Sony Corporation
    Inventors: Junichi Yamashita, Katsuhide Uchino
  • Publication number: 20140285406
    Abstract: A gray-scale voltage generating circuit includes: a ladder resistor circuit including a plurality of resistors connected in series to one another, and configured to output a plurality of gray-scale voltages with different voltage values from ends of the respective resistors; and a constant current source configured to be connected in series to the ladder resistor circuit, in which the constant current source includes a current source transistor configured to be connected in series to the ladder resistor circuit, and a voltage setting section configured to select one voltage from the plurality of voltages and set the selected voltage as a voltage determining a current that is to flow through the current source transistor.
    Type: Application
    Filed: February 26, 2014
    Publication date: September 25, 2014
    Applicant: SONY CORPORATION
    Inventors: Kei Kimura, Yusuke Onoyama, Junichi Yamashita