Patents by Inventor Shigetsugu Yamanaka

Shigetsugu Yamanaka 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: 10170045
    Abstract: A display device includes a display unit including multiple pixels, and a driving circuit that drives the display unit following a color assignation rule. The multiple pixels are classified into first through fourth groups such that groups to which the pixels belong are different from all groups to which pixels belong that are adjacent in eight directions, and pixels adjacent in 8 directions to pixels belonging to the same group, are of the same groups. The first through fourth colors are respectively assigned to the pixels of the first through fourth groups in the first subframe, the second through fourth and first colors are respectively assigned in the second subframe, the third, fourth, first, and second colors are respectively assigned in the third subframe, and the fourth and first through third colors are respectively assigned in the fourth subframe.
    Type: Grant
    Filed: June 24, 2014
    Date of Patent: January 1, 2019
    Assignee: Sharp Kabushiki Kaisha
    Inventor: Shigetsugu Yamanaka
  • Publication number: 20180366061
    Abstract: An organic EL display device includes: a pixel circuit drive unit configured to drive pixel circuits while performing a property measuring process in which a property of circuit elements is measured; a parameter table configured to store parameter values derived from monitoring data obtained in the property measuring process; a compensation computation unit configured to correct externally provided image data based on the parameter values stored in the parameter table, so as to generate a digital video signal to be fed to the pixel circuits; a temperature sensor configured to sense temperature; and a monitoring control section configured to control an execution frequency of the property measuring process in accordance with the sensed temperature. The monitoring control section increases the execution frequency of the property measuring process with an increase in the sensed temperature.
    Type: Application
    Filed: December 13, 2016
    Publication date: December 20, 2018
    Inventors: HIROYUKI FURUKAWA, NORITAKA KISHI, KAZUYOSHI YOSHIYAMA, SHIGETSUGU YAMANAKA, NAOKO GOTO, TAMOTSU SAKAI, KATSUYA OTOI
  • Publication number: 20180342208
    Abstract: In a current measurement period set in a pause period, a display device of the present invention applies measurement voltages to data lines (S1 to Sm) and measures currents outputted to monitoring lines (M1 to Mm) from m pixel circuits (18), and then applies data voltages generated corresponding to video signals to the data lines (S1 to Sm).
    Type: Application
    Filed: August 2, 2018
    Publication date: November 29, 2018
    Inventors: Daichi NISHIKAWA, Yasuyuki OGAWA, Kaoru YAMAMOTO, Noritaka KISHI, Shigetsugu YAMANAKA, Masanori OHARA, Noboru NOGUCHI
  • Patent number: 10141020
    Abstract: An initial current ratio calculation unit obtains an initial current ratio for each pixel based on a current measurement result by a data line drive/current measurement circuit. A light emission current efficiency calculation unit obtains a light emission current efficiency for each pixel referring to an LUT, based on a measured operating temperature and the initial current ratio. A first correction unit corrects a video signal for each pixel in view of characteristics of each pixel, based on the current measurement result and the light emission current efficiency. A second correction unit obtains a correction term for each pixel in view of a difference in the light emission current efficiency compared to neighboring pixels, based on a two-dimensional distribution of the light emission current efficiency. The correction term obtained by the second correction unit is added to the video signal corrected to obtain a corrected video signal.
    Type: Grant
    Filed: July 16, 2015
    Date of Patent: November 27, 2018
    Assignee: SHARP KABUSHIKI KAISHA
    Inventor: Shigetsugu Yamanaka
  • Patent number: 10074313
    Abstract: In a current measurement period set in a pause period, a display device of the present invention applies measurement voltages to data lines (S1 to Sm) and measures currents outputted to monitoring lines (M1 to Mm) from m pixel circuits (18), and then applies data voltages generated corresponding to video signals to the data lines (S1 to Sm).
    Type: Grant
    Filed: June 5, 2015
    Date of Patent: September 11, 2018
    Assignee: SHARP KABUSHIKI KAISHA
    Inventors: Daichi Nishikawa, Yasuyuki Ogawa, Kaoru Yamamoto, Noritaka Kishi, Shigetsugu Yamanaka, Masanori Ohara, Noboru Noguchi
  • Patent number: 9953563
    Abstract: A data line drive circuit provides a voltage according to a detection voltage and to a reference voltage, between the gate and source of a drive transistor in a pixel circuit, and detects a drive current having passed through the drive transistor and outputted external to the pixel circuit. A threshold voltage correction memory stores, for each pixel circuit, data representing a threshold voltage of the drive transistor. A display control circuit controls the reference voltage based on the data stored in the threshold voltage correction memory. By this, even if the threshold voltage of the drive transistor is changed, the drive current can be detected with a high accuracy. The threshold voltage correction memory may store, for each pixel circuit, data representing a difference between the threshold voltage of the drive transistor and the reference voltage.
    Type: Grant
    Filed: March 4, 2014
    Date of Patent: April 24, 2018
    Assignee: SHARP KABUSHIKI KAISHA
    Inventors: Noritaka Kishi, Hiromitsu Katsui, Noboru Noguchi, Masanori Ohara, Shigetsugu Yamanaka, Yoshifumi Ohta
  • Publication number: 20180082642
    Abstract: A display device that is configured to include two independent shift registers and is capable of performing a monitoring process without causing the degradation of display quality or the occurrence of abnormal operation is implemented. In a display device including: a writing control shift register composed of a plurality of first unit circuits (30) each including a first boost circuit (320) and a first output node reset circuit (330); and a monitoring control shift register composed of a plurality of second unit circuits (40) each including a second boost circuit (420) and a second output node reset circuit (430), current drive capability of the first boost circuit (320) is higher than current drive capability of the second boost circuit (420), and current drive capability of the second output node reset circuit (430) is higher than current drive capability of the first output node reset circuit (330).
    Type: Application
    Filed: March 25, 2016
    Publication date: March 22, 2018
    Inventors: Shigetsugu YAMANAKA, Noboru NOGUCHI, Masanori OHARA, Noritaka KISHI
  • Patent number: 9837023
    Abstract: In a pixel circuit, TFTs are connected and driven such that a threshold voltage Vth of a TFT, which is a drive transistor, can be held in a threshold holding capacitor having a capacitance value c1, voltages, including a data potential Vdata representing an image to be displayed, can be held in a data holding capacitor having a capacitance value c2, and charges in the data holding capacitor and the threshold holding capacitor are redistributed at the time of light emission. As a result, a potential obtained by multiplying the data potential Vdata by c1/(c1+c2) is provided to a gate potential of the TFT.
    Type: Grant
    Filed: June 30, 2017
    Date of Patent: December 5, 2017
    Assignee: SHARP KABUSHIKI KAISHA
    Inventors: Noritaka Kishi, Noboru Noguchi, Masanori Ohara, Shigetsugu Yamanaka
  • Publication number: 20170316741
    Abstract: In a pixel circuit, TFTs are connected and driven such that a threshold voltage Vth of a TFT, which is a drive transistor, can be held in a threshold holding capacitor having a capacitance value c1, voltages, including a data potential Vdata representing an image to be displayed, can be held in a data holding capacitor having a capacitance value c2, and charges in the data holding capacitor and the threshold holding capacitor are redistributed at the time of light emission. As a result, a potential obtained by multiplying the data potential Vdata by c1/(c1+c2) is provided to a gate potential of the TFT.
    Type: Application
    Filed: June 30, 2017
    Publication date: November 2, 2017
    Inventors: Noritaka KISHI, Noboru NOGUCHI, Masanori OHARA, Shigetsugu YAMANAKA
  • Patent number: 9734762
    Abstract: In a pixel circuit (10), TFTs (12) to (16) are connected and driven such that a threshold voltage Vth of a TFT (11), which is a drive transistor, can be held in a threshold holding capacitor (19) having a capacitance value c1, voltages, including a data potential Vdata representing an image to be displayed, can be held in a data holding capacitor (18) having a capacitance value c2, and charges in the data holding capacitor (18) and the threshold holding capacitor (19) are redistributed at the time of light emission. As a result, a potential obtained by multiplying the data potential Vdata by c1/(c1+c2) is provided to a gate potential of the TFT (11).
    Type: Grant
    Filed: October 26, 2012
    Date of Patent: August 15, 2017
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Noritaka Kishi, Noboru Noguchi, Masanori Ohara, Shigetsugu Yamanaka
  • Patent number: 9697769
    Abstract: In a display device having a pixel circuit including an electro-optical element in which brightness is controlled by a current, and including a drive transistor for controlling a current to be supplied to the electro-optical element, a drive method therefor includes: a noise measurement step of measuring noise; characteristic detection steps of detecting characteristics of the drive transistor and the electro-optical element; a correction data update step of updating correction data, which serves for correcting a video signal, based on detection results in the characteristic detection step; and a video signal correction step of correcting the video signal based on the correction data. When noise with a standard value or more is detected in the noise measurement step, processing of the correction data update step is not performed.
    Type: Grant
    Filed: July 29, 2014
    Date of Patent: July 4, 2017
    Assignee: SHARP KABUSHIKI KAISHA
    Inventors: Noritaka Kishi, Noboru Noguchi, Shigetsugu Yamanaka, Masanori Ohara
  • Publication number: 20170186373
    Abstract: In a current measurement period set in a pause period, a display device of the present invention applies measurement voltages to data lines (S1 to Sm) and measures currents outputted to monitoring lines (M1 to Mm) from m pixel circuits (18), and then applies data voltages generated corresponding to video signals to the data lines (S1 to Sm).
    Type: Application
    Filed: June 5, 2015
    Publication date: June 29, 2017
    Inventors: Daichi NISHIKAWA, Yasuyuki OGAWA, Kaoru YAMAMOTO, Noritaka KISHI, Shigetsugu YAMANAKA, Masanori OHARA, Noboru NOGUCHI
  • Publication number: 20170162226
    Abstract: An initial current ratio calculation unit obtains an initial current ratio for each pixel based on a current measurement result by a data line drive/current measurement circuit. A light emission current efficiency calculation unit obtains a light emission current efficiency for each pixel referring to an LUT, based on a measured operating temperature and the initial current ratio. A first correction unit corrects a video signal for each pixel in view of characteristics of each pixel, based on the current measurement result and the light emission current efficiency. A second correction unit obtains a correction term for each pixel in view of a difference in the light emission current efficiency compared to neighboring pixels, based on a two-dimensional distribution of the light emission current efficiency. The correction term obtained by the second correction unit is added to the video signal corrected to obtain a corrected video signal.
    Type: Application
    Filed: July 16, 2015
    Publication date: June 8, 2017
    Applicant: SHARP KABUSHIKI KAISHA
    Inventor: Shigetsugu YAMANAKA
  • Publication number: 20160372043
    Abstract: A display device includes a display unit including multiple pixels, and a driving circuit that drives the display unit following a color assignation rule. The multiple pixels are classified into first through fourth groups such that groups to which the pixels belong are different from all groups to which pixels belong that are adjacent in eight directions, and pixels adjacent in 8 directions to pixels belonging to the same group, are of the same groups. The first through fourth colors are respectively assigned to the pixels of the first through fourth groups in the first subframe, the second through fourth and first colors are respectively assigned in the second subframe, the third, fourth, first, and second colors are respectively assigned in the third subframe, and the fourth and first through third colors are respectively assigned in the fourth subframe.
    Type: Application
    Filed: June 24, 2014
    Publication date: December 22, 2016
    Inventor: Shigetsugu YAMANAKA
  • Patent number: 9495894
    Abstract: An embodiment of the present invention is directed to reducing a memory capacity required for saving compensating data (data used for compensating variations and the like in characteristic of a drive transistor) compared to conventional examples, in a display device. An organic EL display device using an oxide TFT for a drive transistor is provided with: a low pass filter for extracting low frequency component data from pixel current data as data of a drive current of the drive transistor; a first computing portion for obtaining high frequency component data by obtaining a difference between the pixel current data and the low frequency component data; a down-sampling portion for extracting data from the low frequency component data at predetermined sampling intervals; and a high frequency signal compression processing portion for extracting only high amplitude data out of the high frequency component data.
    Type: Grant
    Filed: December 25, 2013
    Date of Patent: November 15, 2016
    Assignee: SHARP KABUSHIKI KAISHA
    Inventors: Shigetsugu Yamanaka, Shinji Nakagawa, Hiroyuki Furukawa, Yoshifumi Ohta
  • Patent number: 9361823
    Abstract: In a display device (110) provided with pixel circuits including organic EL elements, a display control circuit (1) calculates a voltage drop amount VRI of a power line due to display for each frame on the basis of an integrated value for display data, and a tone voltage generation circuit (9) adjusts reference voltages for a tone voltage on the basis of the integrated value in order to compensate for the voltage drop amount VRI. As a result, it is possible to compensate for the voltage drop of the power line with accuracy without increasing power consumption and the wiring in the pixel circuits.
    Type: Grant
    Filed: February 28, 2013
    Date of Patent: June 7, 2016
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Kengo Takahama, Shigetsugu Yamanaka
  • Publication number: 20160104422
    Abstract: In a display device having a pixel circuit including an electro-optical element in which brightness is controlled by a current, and including a drive transistor for controlling a current to be supplied to the electro-optical element, a drive method therefor includes: a noise measurement step of measuring noise; characteristic detection steps of detecting characteristics of the drive transistor and the electro-optical element; a correction data update step of updating correction data, which serves for correcting a video signal, based on detection results in the characteristic detection step; and a video signal correction step of correcting the video signal based on the correction data. When noise with a standard value or more is detected in the noise measurement step, processing of the correction data update step is not performed.
    Type: Application
    Filed: July 29, 2014
    Publication date: April 14, 2016
    Inventors: Noritaka KISHI, Noboru NOGUCHI, Shigetsugu YAMANAKA, Masanori OHARA
  • Publication number: 20160055791
    Abstract: A data line drive circuit provides a voltage according to a detection voltage and to a reference voltage, between the gate and source of a drive transistor in a pixel circuit, and detects a drive current having passed through the drive transistor and outputted external to the pixel circuit. A threshold voltage correction memory stores, for each pixel circuit, data representing a threshold voltage of the drive transistor. A display control circuit controls the reference voltage based on the data stored in the threshold voltage correction memory. By this, even if the threshold voltage of the drive transistor is changed, the drive current can be detected with a high accuracy. The threshold voltage correction memory may store, for each pixel circuit, data representing a difference between the threshold voltage of the drive transistor and the reference voltage.
    Type: Application
    Filed: March 4, 2014
    Publication date: February 25, 2016
    Inventors: Noritaka KISHI, Hiromitsu KATSUI, Noboru NOGUCHI, Masanori OHARA, Shigetsugu YAMANAKA, Yoshifumi OHTA
  • Patent number: 9243779
    Abstract: A multi display system (10) includes a plurality of display panels (100) disposed adjacently to each other via a boundary portion (20), and a translucent cover (113) disposed on the plurality of display panels (100). The translucent cover (113) is disposed so as to cover the boundary portion (20) and overlapping with both of the plurality of display panels (100) which are disposed adjacently. The translucent cover (113) is constituted by a supporting portion (113P) which covers at least part of the display panel excluding the boundary portion (20), and a portion which is continuous to the supporting portion (113P) and includes a concave portion (113C) formed on the observer side in a position facing the boundary portion (20).
    Type: Grant
    Filed: January 26, 2012
    Date of Patent: January 26, 2016
    Assignee: SHARP KABUSHIKI KAISHA
    Inventor: Shigetsugu Yamanaka
  • Patent number: 9231042
    Abstract: Occurrence of a crosstalk phenomenon in a light-emitting device is inhibited. A light-emitting device including an insulating layer 416; a first lower electrode 421a formed over the insulating layer; a second lower electrode 421b formed over the insulating layer; a partition 418 formed over the insulating layer and positioned between the first lower electrode and the second lower electrode; a stacked-layer film 423 which is formed over the first lower electrode, the partition, and the second lower electrode and includes a light-emitting layer containing a light-emitting substance and a layer having higher conductivity than that of the light-emitting layer; an upper electrode 422 formed over the stacked-layer film; and a shield electrode 419 which is formed under the partition and does not overlap with the first lower electrode and the second lower electrode.
    Type: Grant
    Filed: February 4, 2014
    Date of Patent: January 5, 2016
    Assignees: Semiconductor Energy Laboratory Co., Ltd., Sharp Kabushiki Kaisha
    Inventors: Yusuke Nishido, Yoshiharu Hirakata, Shigetsugu Yamanaka