Patents by Inventor Toshiyuki Nagatsuma

Toshiyuki Nagatsuma 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: 11749214
    Abstract: A display device is provided and includes display panel comprising plurality of pixels; and light source device configured to emit light that illuminates display panel, wherein display panel is configured to control operation of light source device, display panel does not lower luminance of light for second predetermined time or longer after display panel has raised luminance of light by predetermined amount of luminance change or more within first predetermined time, and when image changes from first image other than raster image and ramp image to second image that is either of raster image and ramp image, display panel lowers luminance of light within time shorter than second predetermined time even after luminance of light has been raised by predetermined amount of luminance change or more within first predetermined time.
    Type: Grant
    Filed: March 22, 2021
    Date of Patent: September 5, 2023
    Assignee: Japan Display Inc.
    Inventors: Kazuhiko Sako, Tsutomu Harada, Naoyuki Takasaki, Toshiyuki Nagatsuma
  • Publication number: 20210210028
    Abstract: A display device is provided and includes display panel comprising plurality of pixels; and light source device configured to emit light that illuminates display panel, wherein display panel is configured to control operation of light source device, display panel does not lower luminance of light for second predetermined time or longer after display panel has raised luminance of light by predetermined amount of luminance change or more within first predetermined time, and when image changes from first image other than raster image and ramp image to second image that is either of raster image and ramp image, display panel lowers luminance of light within time shorter than second predetermined time even after luminance of light has been raised by predetermined amount of luminance change or more within first predetermined time.
    Type: Application
    Filed: March 22, 2021
    Publication date: July 8, 2021
    Inventors: Kazuhiko SAKO, Tsutomu HARADA, Naoyuki TAKASAKI, Toshiyuki NAGATSUMA
  • Patent number: 10957261
    Abstract: According to an aspect, a display device includes a display unit including a plurality of pixels, a light source device that emits light that illuminates the display unit, and a controller that controls operation of the light source device. The controller does not lower luminance of the light for a second predetermined time or longer after the controller has raised the luminance of the light by a predetermined amount of luminance change or more within a first predetermined time.
    Type: Grant
    Filed: January 15, 2019
    Date of Patent: March 23, 2021
    Assignee: Japan Display Inc.
    Inventors: Kazuhiko Sako, Tsutomu Harada, Naoyuki Takasaki, Toshiyuki Nagatsuma
  • Publication number: 20190221168
    Abstract: According to an aspect, a display device includes a display unit including a plurality of pixels, a light source device that emits light that illuminates the display unit, and a controller that controls operation of the light source device. The controller does not lower luminance of the light for a second predetermined time or longer after the controller has raised the luminance of the light by a predetermined amount of luminance change or more within a first predetermined time.
    Type: Application
    Filed: January 15, 2019
    Publication date: July 18, 2019
    Inventors: Kazuhiko SAKO, Tsutomu HARADA, Naoyuki TAKASAKI, Toshiyuki NAGATSUMA
  • Patent number: 9978339
    Abstract: A display device includes a signal processing unit that receives input signals, and calculates output signals to a first sub-pixel, a second sub-pixel, a third sub-pixel, and a fourth sub-pixel. The signal processing unit calculates a frequency of pixels belonging to each of a plurality of partitions using a light quantity of a surface light source. The signal processing unit calculates an index value for each of the partitions by at least multiplying the cumulative frequency being obtained by sequentially adding the frequency of pixels from a partition having the maximum light quantity among the partitions, and the number of partitions representing a position of a partition to which the cumulative frequency belongs counted from the partition having the maximum light quantity. The signal processing unit controls luminance of the surface light source based on a partition in which the index value exceeds a threshold.
    Type: Grant
    Filed: July 12, 2017
    Date of Patent: May 22, 2018
    Assignee: Japan Display Inc.
    Inventors: Kojiro Ikeda, Toshiyuki Nagatsuma, Masaaki Kabe, Amane Higashi, Tae Kurokawa, Fumitaka Gotoh, Akira Sakaigawa
  • Patent number: 9972255
    Abstract: According to an aspect, a display device includes: an image display panel in which pixels are arranged in a two-dimensional matrix, each of the pixels including a first sub-pixel displaying a first color, a second sub-pixel displaying a second color, a third sub-pixel displaying a third color, and a fourth sub-pixel displaying a fourth color; and a signal processing unit that converts input values of input signals into extended values in an extended color space to generate output signals, and outputs the generated output signals to the image display panel. The signal processing unit changes the output signals for the first to fourth sub-pixels based on at least saturation of the input signals.
    Type: Grant
    Filed: May 28, 2015
    Date of Patent: May 15, 2018
    Assignee: Japan Display Inc.
    Inventors: Masaaki Kabe, Toshiyuki Nagatsuma, Amane Higashi, Yoko Fukunaga
  • Patent number: 9972253
    Abstract: Provided are a display apparatus and an illumination apparatus including: a light source; a time division control unit that performs a time division operation on a value represented by a first luminance control signal of a first bit number for controlling luminance of the light source to generate second luminance control signals each having a second bit number that is smaller than the first bit number and generates third luminance control signals each having a pulse width that corresponds to one of the values represented by the second luminance control signals; and a drive unit that generates drive signals for causing the light source to emit light on the basis of the third luminance control signals and supplies the drive signals to the light source.
    Type: Grant
    Filed: April 9, 2015
    Date of Patent: May 15, 2018
    Assignee: Japan Display Inc.
    Inventors: Fumitaka Gotoh, Tsutomu Harada, Toshiyuki Nagatsuma, Akira Sakaigawa, Masaaki Kabe, Tae Kurokawa, Kojiro Ikeda
  • Patent number: 9830886
    Abstract: According to an aspect, a display device includes an image display panel in which pixels each including first to fourth sub-pixels are arranged in a two-dimensional matrix; and a signal processing unit that converts an input signal into an output signal and outputs the generated output signal to the image display panel. The signal processing unit determines an expansion coefficient, obtains a generated signal of the fourth sub-pixel in each pixel based on input signals of the first to the third sub-pixels in the pixel itself and the expansion coefficient, obtains an output signal for the fourth sub-pixel in each pixel based on a generated signal of the fourth sub-pixel in the pixel itself and a generated signal of the fourth sub-pixel in an adjacent pixel to be output to the fourth sub-pixel.
    Type: Grant
    Filed: May 12, 2015
    Date of Patent: November 28, 2017
    Assignee: Japan Display Inc.
    Inventors: Amane Higashi, Toshiyuki Nagatsuma, Akira Sakaigawa, Masaaki Kabe
  • Publication number: 20170330530
    Abstract: A display device includes a signal processing unit that receives input signals, and calculates output signals to a first sub-pixel, a second sub-pixel, a third sub-pixel, and a fourth sub-pixel. The signal processing unit calculates a frequency of pixels belonging to each of a plurality of partitions using a light quantity of a surface light source. The signal processing unit calculates an index value for each of the partitions by at least multiplying the cumulative frequency being obtained by sequentially adding the frequency of pixels from a partition having the maximum light quantity among the partitions, and the number of partitions representing a position of a partition to which the cumulative frequency belongs counted from the partition having the maximum light quantity. The signal processing unit controls luminance of the surface light source based on a partition in which the index value exceeds a threshold.
    Type: Application
    Filed: July 12, 2017
    Publication date: November 16, 2017
    Inventors: Kojiro Ikeda, Toshiyuki Nagatsuma, Masaaki Kabe, Amane Higashi, Tae Kurokawa, Fumitaka Gotoh, Akira Sakaigawa
  • Patent number: 9773470
    Abstract: A display device includes: an image display panel including a plurality of pixels each including first to fourth sub-pixels; and a signal processing unit. The signal processing unit determines an expansion coefficient related to the image display panel, obtains output signals of the first to the third sub-pixels based on at least input signals of the first to the third sub-pixels and the expansion coefficient to be output to the first to the third sub-pixels respectively, obtains a fourth sub-pixel correction value as a correction value of an output signal of the fourth sub-pixel based on the input signals of the first to the third sub-pixels and the expansion coefficient, and obtains the output signal of the fourth sub-pixel based on the input signals of the first to third sub-pixels, the expansion coefficient, and the fourth sub-pixel correction value to be output to the fourth sub-pixel.
    Type: Grant
    Filed: April 14, 2015
    Date of Patent: September 26, 2017
    Assignee: Japan Display Inc.
    Inventors: Tae Kurokawa, Akira Sakaigawa, Masaaki Kabe, Kojiro Ikeda, Fumitaka Gotoh, Amane Higashi, Toshiyuki Nagatsuma
  • Patent number: 9734766
    Abstract: A lighting device includes a light source and a control section. The control section has a first mode and a second mode as luminance setting modes of the light source and sets, in order to exercise variable control of a reach time taken to change luminance of the light source to a determined value, the reach time on the basis of the first mode for a determined period at the time of switching from the first mode to the second mode.
    Type: Grant
    Filed: July 21, 2015
    Date of Patent: August 15, 2017
    Assignee: Japan Display Inc.
    Inventors: Akira Sakaigawa, Toshiyuki Nagatsuma
  • Patent number: 9734772
    Abstract: A display device includes: a display unit including pixels arranged in a matrix therein, each of the pixels including a first sub-pixel that displays a first color component, a second sub-pixel that displays a second color component, a third sub-pixel that displays a third color component, and a fourth sub-pixel that displays a fourth color component; and a signal processing unit that receives input signals that are capable of being displayed with the first sub-pixel, the second sub-pixel, and the third sub-pixel, and calculates output signals to the first, second, third, and fourth sub-pixels. The signal processing unit generates converted input signals with changed saturation among the input signals. The signal processing unit calculates output signals to the first sub-pixel, the second sub-pixel, and the third sub-pixel based on the converted input signals and an amount of increase in brightness caused by the fourth sub-pixel.
    Type: Grant
    Filed: April 24, 2015
    Date of Patent: August 15, 2017
    Assignee: Japan Display Inc.
    Inventors: Masashi Mitsui, Toshiyuki Nagatsuma
  • Patent number: 9728161
    Abstract: A display device includes a signal processing unit that receives input signals, and calculates output signals to a first sub-pixel, a second sub-pixel, a third sub-pixel, and a fourth sub-pixel. The signal processing unit calculates a frequency of pixels belonging to each of a plurality of partitions using a light quantity of a surface light source. The signal processing unit calculates an index value for each of the partitions by at least multiplying the cumulative frequency being obtained by sequentially adding the frequency of pixels from a partition having the maximum light quantity among the partitions, and the number of partitions representing a position of a partition to which the cumulative frequency belongs counted from the partition having the maximum light quantity. The signal processing unit controls luminance of the surface light source based on a partition in which the index value exceeds a threshold.
    Type: Grant
    Filed: April 22, 2015
    Date of Patent: August 8, 2017
    Assignee: Japan Display Inc.
    Inventors: Kojiro Ikeda, Toshiyuki Nagatsuma, Masaaki Kabe, Amane Higashi, Tae Kurokawa, Fumitaka Gotoh, Akira Sakaigawa
  • Patent number: 9704426
    Abstract: A display device includes a first processing circuit mounted on a substrate separate from a translucent substrate constituting a display panel, and a second processing circuit mounted on the translucent substrate. The first and the second processing circuits receive the same image data. The first processing circuit includes a determination unit that uses color values of a plurality of pixels constituting an image based on the image data to determine an expansion coefficient value serving as a value for improving luminance of the image, and outputs the expansion coefficient value to the second processing circuit. The second processing circuit includes an expansion processing unit that uses the expansion coefficient value to provide expansion processing for improving the luminance of the image for the image based on the image data.
    Type: Grant
    Filed: May 6, 2015
    Date of Patent: July 11, 2017
    Assignee: Japan Display Inc.
    Inventors: Tsutomu Harada, Naoyuki Takasaki, Toshiyuki Nagatsuma, Hirokazu Tatsuno
  • Patent number: 9679535
    Abstract: A display device includes a conversion section which generate a data conversion signal including a first number of bits from an input signal, an error dispersion section which generates a display control signal including a second number of bits that is smaller than the first number of bits from the data conversion signal and which spatially disperses errors that occur at the time of generating the display control signal, and a display panel section which displays an image on the basis of the display control signal.
    Type: Grant
    Filed: April 13, 2015
    Date of Patent: June 13, 2017
    Assignee: Japan Display Inc.
    Inventors: Akira Sakaigawa, Toshiyuki Nagatsuma, Amane Higashi, Masaaki Kabe
  • Patent number: 9633614
    Abstract: According to an aspect, a display device includes an image display panel and a signal processing unit. The signal processing unit derives a generation signal for a fourth sub-pixel in each of pixels based on an input signal for a first sub-pixel, an input signal for a second sub-pixel, an input signal for a third sub-pixel, and an extension coefficient. The signal processing unit derives a correction value based on a hue of an input color corresponding to a color to be displayed based on the input signal for the first sub-pixel, the input signal for the second sub-pixel, and the input signal for the third sub-pixel. The signal processing unit derives the output signal for the fourth sub-pixel in each of the pixels based on the generation signal for the fourth sub-pixel and the correction value and outputs the output signal to the fourth sub-pixel.
    Type: Grant
    Filed: December 17, 2015
    Date of Patent: April 25, 2017
    Assignee: Japan Display Inc.
    Inventors: Masaaki Kabe, Fumitaka Gotoh, Kazuhiko Sako, Toshiyuki Nagatsuma, Kojiro Ikeda, Tsutomu Harada
  • Patent number: 9552758
    Abstract: A display device includes an image processing unit that performs image processing on image data input from the outside, and performs display output corresponding to the image data on which image processing is performed by the image processing unit. The image processing unit includes a first processing circuit that simply replaces colors of an image to limit the number of colors used for the image to a predetermined number equal to or smaller than 16, a second processing circuit that performs image processing including arithmetic processing for improving luminance of a plurality of pixels constituting the image displayed on the display device corresponding to the image data; and a switching unit that causes the second processing circuit to perform image processing, and causes the first processing circuit to perform image processing when performing the image processing while saving more power than the second processing circuit.
    Type: Grant
    Filed: May 11, 2015
    Date of Patent: January 24, 2017
    Assignee: Japan Display Inc.
    Inventors: Tsutomu Harada, Hiroki Uchiyama, Toshiyuki Nagatsuma
  • Patent number: 9501983
    Abstract: According to an aspect, a color conversion device includes a signal processing unit and a signal output unit. When a color specified in a predetermined color space by color data based on input signals is a color outside a defined color gamut defined in the color space, the signal processing unit generates in-defined-gamut data, and when the color specified in the color space by the color data based on the input signals is a color on a border of or inside the defined color gamut, the signal processing unit does not convert the color data based on the input signals into color data of a color different from that specified by the color data based on the input signals, and generates in-defined-gamut data identical to the color data based on the input signals, and. The signal processing unit generates output signals based on the in-defined-gamut data.
    Type: Grant
    Filed: February 4, 2014
    Date of Patent: November 22, 2016
    Assignee: Japan Display Inc.
    Inventors: Hirokazu Tatsuno, Toshiyuki Nagatsuma, Akira Sakaigawa, Masaaki Kabe
  • Patent number: 9390679
    Abstract: According to an aspect, a display device includes: an image display panel; a signal processing unit; and a signal processing circuit. The signal processing unit calculates an extension coefficient ? for an input signal, calculates an output signal of a first sub-pixel, calculates an output signal of a second sub-pixel, calculates an output signal of a third sub-pixel, calculates an output signal of a fourth sub-pixel, and calculates a control signal. The signal processing circuit performs filtering processing on the control signal by a set first time constant to calculate and output a light-source device control signal, when the control signal is smaller than a set threshold value, and performs filtering processing on the control signal by a set second time constant to calculate and output the light-source device control signal, when the control signal is equal to or larger than the threshold value.
    Type: Grant
    Filed: February 20, 2014
    Date of Patent: July 12, 2016
    Assignee: Japan Display Inc.
    Inventors: Tsutomu Harada, Masaaki Kabe, Fumitaka Goto, Toshiyuki Nagatsuma
  • Publication number: 20160196787
    Abstract: According to an aspect, a display device includes an image display panel and a signal processing unit. The signal processing unit derives a generation signal for a fourth sub-pixel in each of pixels based on an input signal for a first sub-pixel, an input signal for a second sub-pixel, an input signal for a third sub-pixel, and an extension coefficient. The signal processing unit derives a correction value based on a hue of an input color corresponding to a color to be displayed based on the input signal for the first sub-pixel, the input signal for the second sub-pixel, and the input signal for the third sub-pixel. The signal processing unit derives the output signal for the fourth sub-pixel in each of the pixels based on the generation signal for the fourth sub-pixel and the correction value and outputs the output signal to the fourth sub-pixel.
    Type: Application
    Filed: December 17, 2015
    Publication date: July 7, 2016
    Inventors: Masaaki KABE, Fumitaka GOTOH, Kazuhiko SAKO, Toshiyuki NAGATSUMA, Kojiro IKEDA, Tsutomu HARADA