Patents by Inventor Norio Ohmura

Norio Ohmura 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: 9959821
    Abstract: In a liquid crystal display device, a drive unit is controlled in a direction of eliminating a polarity bias of a data voltage corresponding to image data at a point of time when a refresh signal for updating an image displayed on a display unit by periodical refreshment or forced refreshment is generated, and the polarity bias is obtained for each of subsequent frame periods. In this manner, not only the polarity bias after the point of time when the refresh signal is generated is obtained so that the polarity bias at the point of time when the refresh signal is generated is eliminated, but also the polarity bias is repeatedly obtained in the same way every time the refresh signal is generated, and accordingly, the polarity bias can be prevented from being increased.
    Type: Grant
    Filed: September 1, 2014
    Date of Patent: May 1, 2018
    Assignee: SHARP KABUSHIKI KAISHA
    Inventors: Kentaroh Uemura, Norio Ohmura, Tatsuhiko Suyama, Noriyuki Tanaka
  • Patent number: 9953594
    Abstract: When a SLEEPIN Command is inputted to the liquid crystal display device, the liquid crystal display device controls a source driver and a gate driver to generate an alternating current voltage and apply the generated alternating current voltage to a liquid crystal layer, in order to eliminate charge storage due to impurity ions distributed unevenly due to a polarity bias caused by a voltage applied to the liquid crystal layer until a point of time when the Command is inputted. In this manner, the liquid crystal display device shifts to a sleep period in a state where the charge storage due to the unevenly distributed impurity ions is eliminated. Therefore, when the liquid crystal display device resumes from the sleep period, generation of an afterimage due to burn-in of liquid crystal and generation of a flicker due to deviation of an optimum common voltage do not occur.
    Type: Grant
    Filed: November 7, 2014
    Date of Patent: April 24, 2018
    Assignee: SHARP KABUSHIKI KAISHA
    Inventors: Kentaroh Uemura, Norio Ohmura, Tatsuhiko Suyama
  • Patent number: 9922613
    Abstract: In a liquid crystal display device, it is determined whether or not image data inputted from the outside has changed from image data of the previous frame by comparing those image data with respect to each line. As a result, when it is determined that the image data has changed, an entire screen is not rewritten, but image data from a top of a screen as a fixed position to a last line with the image data having changed are read from a frame memory and written into a pixel formation portion. Accordingly, of the screen for one frame, a screen from a top thereof to the last line where the image change has been detected is updated, and on subsequent lines, an image of the previous frame is continuously displayed.
    Type: Grant
    Filed: July 3, 2015
    Date of Patent: March 20, 2018
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Tatsuhiko Suyama, Norio Ohmura, Noriyuki Tanaka, Makoto Yokoyama
  • Patent number: 9865206
    Abstract: Provided are a liquid crystal display device and a driving method therefor that do not cause problems such as occurrence of flicker even when performing pause driving. When an off signal Soff instructing to turn off power is inputted, a polarity bias value W at the power-off is stored in a balance storage circuit. When the power is turned on again, the polarity bias value W is read from the balance storage circuit and provided to a balance control circuit. The balance control circuit starts insertion of a pause frame period to cancel out the polarity bias value W. By this, decrementing the polarity bias value W by “1” every insertion of a pause frame period is repeated. Then, at a point of time when the polarity bias value W becomes “0”, insertion of a pause frame period is ceased and normal pause driving is performed.
    Type: Grant
    Filed: February 12, 2014
    Date of Patent: January 9, 2018
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Jin Miyazawa, Kouji Kumada, Norio Ohmura, Noriyuki Tanaka, Tatsuhiko Suyama, Kentaroh Uemura
  • Publication number: 20170358268
    Abstract: Provided is a display device and the like, in which power consumption is reduced in consideration of increased definition of a display image or an increased size of a display panel. In a liquid crystal display device having a power-saving mode in addition to a normal mode, buffers for outputting data signals from a source driver (300) to source lines are made up of positive-polarity buffers (333p) and negative-polarity buffers (333n), and a connection switching circuit 334 is provided between output ends of these buffers and the source driver (300). In the power-saving mode, the buffers (333p, 333n) are connected to source lines by the connection switching circuit (334), while the polarities of the buffers are taken into account, such that the same data signals are applied to two mutually adjacent source lines. Accordingly, although horizontal resolution is halved, half of the buffers in the source driver (300) are halted, thereby enabling great reduction in power consumption.
    Type: Application
    Filed: November 20, 2015
    Publication date: December 14, 2017
    Inventors: Masaaki NISHIO, Hongbing WENG, Norio OHMURA
  • Publication number: 20170162158
    Abstract: In a liquid crystal display device, it is determined whether or not image data inputted from the outside has changed from image data of the previous frame by comparing those image data with respect to each line. As a result, when it is determined that the image data has changed, an entire screen is not rewritten, but image data from a top of a screen as a fixed position to a last line with the image data having changed are read from a frame memory and written into a pixel formation portion. Accordingly, of the screen for one frame, a screen from a top thereof to the last line where the image change has been detected is updated, and on subsequent lines, an image of the previous frame is continuously displayed.
    Type: Application
    Filed: July 3, 2015
    Publication date: June 8, 2017
    Inventors: Tatsuhiko SUYAMA, Norio OHMURA, Noriyuki TANAKA, Makoto YOKOYAMA
  • Patent number: 9626920
    Abstract: In a liquid crystal display device for performing pause driving, occurrence of flicker is effectively suppressed while an increase in power consumption is suppressed. When a frame in which an image signal (DAT) is inputted from an external portion without output of a request signal (RO) for requesting the external portion to input the image signal (DAT) is defined as a first input frame, a reversal driving control portion (10) sets the reversal driving technique in the first input frame to the column-reversal driving while setting the first input frame to a refresh frame defined as a first refresh frame, sets three frames subsequent to the first refresh frame to pause frames, sets a frame subsequent to the final pause frame to a refresh frame defined as a second refresh frame, and sets the reversal driving technique in the second refresh frame to the dot-reversal driving.
    Type: Grant
    Filed: November 13, 2013
    Date of Patent: April 18, 2017
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Tatsuhiko Suyama, Kouji Kumada, Norio Ohmura, Noriyuki Tanaka, Takuya Sone
  • Patent number: 9607541
    Abstract: Provided is a liquid crystal display device capable of reliably reducing power consumption during pause drive by controlling the timing of performing refresh. When there is an image change in externally inputted RGB data, or when the number of consecutive pause frames reaches a predetermined value, if the number of immediately preceding pause frames is less than a threshold BCTH, image signal refresh is performed once, or if the number of pause frames is greater than or equal to the threshold BCTH, boost charge refresh is performed first, and then, the image signal refresh is performed. As a result, it is rendered possible to reduce flicker due to luminance reduction, and it is also rendered possible to eliminate the need to perform refresh consecutively even if the frequency of RGB data is high (e.g., 30 Hz) during pause drive.
    Type: Grant
    Filed: December 20, 2013
    Date of Patent: March 28, 2017
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Noriyuki Tanaka, Tatsuhiko Suyama, Takuya Sone, Norio Ohmura, Kentaroh Uemura, Kouji Kumada
  • Patent number: 9589517
    Abstract: In a liquid crystal display device for performing pause driving, occurrence of flicker is effectively suppressed while an increase in power consumption is suppressed. When an image change determination portion (11) detects an image change in a period from the previous refresh frame until generation of a predetermined number of times of pause frames, a reversal driving control portion (13) sets the next frame after a frame where an image change has been detected to a refresh frame where a reversal driving technique is a column-reversal driving. When the image change determination portion (11) does not detect an image change in the period from the previous refresh frame until generation of the predetermined number of times of pause frames, the reversal driving control portion (13) sets the next frame after the final pause frame to a refresh frame where a reversal driving technique is a dot-reversal driving.
    Type: Grant
    Filed: November 13, 2013
    Date of Patent: March 7, 2017
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Tatsuhiko Suyama, Kouji Kumada, Norio Ohmura, Noriyuki Tanaka, Takuya Sone
  • Publication number: 20160365049
    Abstract: In a liquid crystal display device, a drive unit is controlled in a direction of eliminating a polarity bias of a data voltage corresponding to image data at a point of time when a refresh signal for updating an image displayed on a display unit by periodical refreshment or forced refreshment is generated, and the polarity bias is obtained for each of subsequent frame periods. In this manner, not only the polarity bias after the point of time when the refresh signal is generated is obtained so that the polarity bias at the point of time when the refresh signal is generated is eliminated, but also the polarity bias is repeatedly obtained in the same way every time the refresh signal is generated, and accordingly, the polarity bias can be prevented from being increased.
    Type: Application
    Filed: September 1, 2014
    Publication date: December 15, 2016
    Inventors: Kentaroh UEMURA, Norio OHMURA, Tatsuhiko SUYAMA, Noriyuki TANAKA
  • Publication number: 20160293126
    Abstract: When a SLEEPIN Command is inputted to the liquid crystal display device, the liquid crystal display device controls a source driver and a gate driver to generate an alternating current voltage and apply the generated alternating current voltage to a liquid crystal layer, in order to eliminate charge storage due to impurity ions distributed unevenly due to a polarity bias caused by a voltage applied to the liquid crystal layer until a point of time when the Command is inputted. In this manner, the liquid crystal display device shifts to a sleep period in a state where the charge storage due to the unevenly distributed impurity ions is eliminated. Therefore, when the liquid crystal display device resumes from the sleep period, generation of an afterimage due to burn-in of liquid crystal and generation of a flicker due to deviation of an optimum common voltage do not occur.
    Type: Application
    Filed: November 7, 2014
    Publication date: October 6, 2016
    Applicant: SHARP KABUSHIKI KAISHA
    Inventors: Kentaroh UEMURA, Norio OHMURA, Tatsuhiko SUYAMA
  • Publication number: 20160284281
    Abstract: It is an object of the invention to inhibit deterioration in display quality and reduce electric power consumption in a display apparatus. A display apparatus (1) includes a display panel (2) having a display provided with a plurality of pixels, a backlight unit (3) configured to emit light to the display, a panel controller (4) configured to control writing operation of supplying each of the pixels with a signal to display an image in the display and a suspension period provided between the writing operation and different writing operation, and a backlight unit controller (5) configured to control light quantity of the backlight unit (3) in synchronization with writing operation performed before or after the suspension period.
    Type: Application
    Filed: October 31, 2014
    Publication date: September 29, 2016
    Inventors: Tatsuhiko SUYAMA, Kentaroh UEMURA, Norio OHMURA
  • Patent number: 9443484
    Abstract: In a liquid crystal display device for performing pause driving, occurrence of flicker is effectively suppressed while an increase in power consumption is suppressed. A frame in which an image signal is inputted without requesting an external portion to input the image signal is set as a refresh frame by a reversal driving technique deciding portion. A pause frame counting portion counts the number of times of pause frames since the previous refresh frame as a count value. The comparison portion compares the count value with a previously set threshold. As a result, when the count value is not smaller than the threshold, the reversal driving technique deciding portion sets a reversal driving technique in the first input frame to dot-reversal driving. When the count value is smaller than the threshold, the reversal driving technique deciding portion sets a reversal driving technique in the first input frame to column-reversal driving.
    Type: Grant
    Filed: November 13, 2013
    Date of Patent: September 13, 2016
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Tatsuhiko Suyama, Kouji Kumada, Norio Ohmura, Noriyuki Tanaka, Takuya Sone
  • Publication number: 20160196789
    Abstract: There is provided a liquid crystal display device which is capable of reducing power consumption while preventing liquid crystal deterioration. The liquid crystal display device performs an intermission driving. The liquid crystal display device includes a polarity indication section, which controls a driving section included in the liquid crystal display device so that the data voltages to be written to the pixel formation portions in a first refreshing frame included in the drive period have a same polarity as of the data voltages written to the pixel formation portions in the refreshing frame immediately preceding the first refreshing frame and that the data voltage polarity is inverted for each refreshing frame during the drive period, if the drive period includes an even number of the refreshing frames.
    Type: Application
    Filed: December 20, 2013
    Publication date: July 7, 2016
    Applicant: Sharp Kabushiki Kaisha
    Inventors: Tatsuhiko SUYAMA, Noriyuki TANAKA, Takuya SONE, Norio OHMURA, Kentaroh UEMURA, Kouji KUMADA
  • Publication number: 20160196781
    Abstract: Provided is a liquid crystal display device capable of reliably reducing power consumption during pause drive by controlling the timing of performing refresh. When there is an image change in externally inputted RGB data, or when the number of consecutive pause frames reaches a predetermined value, if the number of immediately preceding pause frames is less than a threshold BCTH, image signal refresh is performed once, or if the number of pause frames is greater than or equal to the threshold BCTH, boost charge refresh is performed first, and then, the image signal refresh is performed. As a result, it is rendered possible to reduce flicker due to luminance reduction, and it is also rendered possible to eliminate the need to perform refresh consecutively even if the frequency of RGB data is high (e.g., 30 Hz) during pause drive.
    Type: Application
    Filed: December 20, 2013
    Publication date: July 7, 2016
    Applicant: Sharp Kabushiki Kaisha
    Inventors: Noriyuki TANAKA, Tatsuhiko SUYAMA, Takuya SONE, Norio OHMURA, Kentaroh UEMURA, Kouji KUMADA
  • Publication number: 20160012789
    Abstract: Provided are a liquid crystal display device and a driving method therefor that do not cause problems such as occurrence of flicker even when performing pause driving. When an off signal Soff instructing to turn off power is inputted, a polarity bias value W at the power-off is stored in a balance storage circuit. When the power is turned on again, the polarity bias value W is read from the balance storage circuit and provided to a balance control circuit. The balance control circuit starts insertion of a pause frame period to cancel out the polarity bias value W. By this, decrementing the polarity bias value W by “1” every insertion of a pause frame period is repeated. Then, at a point of time when the polarity bias value W becomes “0”, insertion of a pause frame period is ceased and normal pause driving is performed.
    Type: Application
    Filed: February 12, 2014
    Publication date: January 14, 2016
    Applicant: Sharp Kabushiki Kaisha
    Inventors: Jin MIYAZAWA, Kouji KUMADA, Norio OHMURA, Noriyuki TANAKA, Tatsuhiko SUYAMA, Kentaroh UEMURA
  • Publication number: 20150302809
    Abstract: In a liquid crystal display device for performing pause driving, occurrence of flicker is effectively suppressed while an increase in power consumption is suppressed. When a frame in which an image signal (DAT) is inputted from an external portion without output of a request signal (RO) for requesting the external portion to input the image signal (DAT) is defined as a first input frame, a reversal driving control portion (10) sets the reversal driving technique in the first input frame to the column-reversal driving while setting the first input frame to a refresh frame defined as a first refresh frame, sets three frames subsequent to the first refresh frame to pause frames, sets a frame subsequent to the final pause frame to a refresh frame defined as a second refresh frame, and sets the reversal driving technique in the second refresh frame to the dot-reversal driving.
    Type: Application
    Filed: November 13, 2013
    Publication date: October 22, 2015
    Inventors: Tatsuhiko SUYAMA, Kouji KUMADA, Norio OHMURA, Noriyuki TANAKA, Takuya SONE
  • Publication number: 20150287372
    Abstract: In a liquid crystal display device for performing pause driving, occurrence of flicker is effectively suppressed while an increase in power consumption is suppressed. When an image change determination portion (11) detects an image change in a period from the previous refresh frame until generation of a predetermined number of times of pause frames, a reversal driving control portion (13) sets the next frame after a frame where an image change has been detected to a refresh frame where a reversal driving technique is a column-reversal driving. When the image change determination portion (11) does not detect an image change in the period from the previous refresh frame until generation of the predetermined number of times of pause frames, the reversal driving control portion (13) sets the next frame after the final pause frame to a refresh frame where a reversal driving technique is a dot-reversal driving.
    Type: Application
    Filed: November 13, 2013
    Publication date: October 8, 2015
    Applicant: Sharp Kabushiki Kaisha
    Inventors: Tatsuhiko Suyama, Kouji Kumada, Norio Ohmura, Noriyuki Tanaka, Takuya Sone
  • Publication number: 20150255028
    Abstract: In a liquid crystal display device for performing pause driving, occurrence of flicker is effectively suppressed while an increase in power consumption is suppressed. A frame in which an image signal is inputted without requesting an external portion to input the image signal is set as a refresh frame by a reversal driving technique deciding portion. A pause frame counting portion counts the number of times of pause frames since the previous refresh frame as a count value. The comparison portion compares the count value with a previously set threshold. As a result, when the count value is not smaller than the threshold, the reversal driving technique deciding portion sets a reversal driving technique in the first input frame to dot-reversal driving. When the count value is smaller than the threshold, the reversal driving technique deciding portion sets a reversal driving technique in the first input frame to column-reversal driving.
    Type: Application
    Filed: November 13, 2013
    Publication date: September 10, 2015
    Applicant: Sharp Kabushiki Kaisha
    Inventors: Tatsuhiko Suyama, Kouji Kumada, Norio Ohmura, Noriyuki Tanaka, Takuya Sone
  • Patent number: 8872809
    Abstract: A liquid crystal display apparatus is disclosed, which is capable of suppressing sound emission caused by the AC drive of liquid crystal while suppressing an increase in power consumption. A non-active period during which polarity reversal of a common electrode signal (VCOM) is repeated at predetermined intervals is provided in each horizontal scanning period. During an active period, a common electrode drive circuit provides a common electrode signal (VCOM) indicating either one of potentials LV1 and LV2 to a common electrode, based on a polarity instruction signal (POL). During the non-active period, the common electrode drive circuit provides a common electrode signal (VCOM) whose potential changes between LV3 and LV4 to the common electrode, based on a reversal timing control signal (CTRL). Here, the amplitude of the common electrode signal (VCOM) for the non-active period is made smaller than the amplitude of the common electrode signal (VCOM) for the active period.
    Type: Grant
    Filed: December 10, 2009
    Date of Patent: October 28, 2014
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Tatsuhiko Suyama, Norio Ohmura