Patents by Inventor Kazunari Tomizawa

Kazunari Tomizawa 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).

  • Publication number: 20130010014
    Abstract: A multi-primary-color liquid crystal panel driver (100) according to the present invention includes: a multi-primary-color converter (110) which performs a multi-primary-color conversion to convert the grayscale levels of an input video signal in each of a plurality of vertical scanning periods into grayscale levels of four or more primary colors; and an overdrive circuit (120) which sets, based on the grayscale levels that have been subjected to the multi-primary-color conversion in one vertical scanning period and on the grayscale levels that have been subjected to the multi-primary-color conversion in another vertical scanning period that is earlier than the one vertical scanning period by at least one period, the grayscale levels of the four or more primary colors in that one vertical scanning period. The present invention provides a multi-primary-color liquid crystal panel that can improve the display quality even when the input video signal has varying grayscale levels.
    Type: Application
    Filed: March 16, 2011
    Publication date: January 10, 2013
    Inventors: Makoto Hasegawa, Kazunari Tomizawa
  • Publication number: 20130010213
    Abstract: A signal conversion circuit is disclosed which is suitably used in a multiprimary liquid crystal display device, and a multiprimary liquid crystal display device having such a signal conversion circuit. A signal conversion circuit according to one embodiment of the present invention is for use in a multiprimary liquid crystal display device, and converts an input video signal to a multiprimary signal corresponding to four or more primary colors. When generating a multiprimary signal for displaying dark skin, the signal conversion circuit according to an embodiment of the present invention applies a conversion to the video signal so that a color difference ?u?v?=((u??u60?)2+(v??v60?)2) is 0.03 or less, the color difference ?u?v? being defined by CIE1976 chromaticity coordinates (u?, v?) representing a chromaticity when the pixel is viewed from the frontal direction and CIE1976 chromaticity coordinates (u60?, v60?) representing a chromaticity when the pixel is viewed from a 60° oblique direction.
    Type: Application
    Filed: September 12, 2012
    Publication date: January 10, 2013
    Applicant: Sharp Kabushiki Kaisha
    Inventors: Kazunari Tomizawa, Tomohiko Mori, Shun Ueki, Takao Muroi
  • Patent number: 8350796
    Abstract: A display device for displaying an image may include display and control sections. The display section, provided by a liquid crystal display (LCD), may be configured to display the image with a luminance in accordance with a display signal voltage, the display section including pixels, each pixel in the LCD including first and second subpixels connected to same source and gate lines. The control section may be configured to divide each frame into first to m-th subframe periods, m being an integer greater than or equal to two, the control section configured to generate first to m-th display signals for the subframe periods for output to the display section such that dividing each frame into the subframe periods does not change a sum luminance output of the display section within each frame. The control section may create a difference between luminances of the first and second subpixels.
    Type: Grant
    Filed: February 28, 2006
    Date of Patent: January 8, 2013
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Kazunari Tomizawa, Tomohiko Mori
  • Patent number: 8344983
    Abstract: A liquid crystal display apparatus includes a plurality of areas in which response speeds greatly different from each other coexist in a pixel. A first replacement process section replaces the image data of the desired target frame with a first gradation, when a gradation transition from a current frame to a desired target frame corresponds to the above gradation transition. A second replacement process section replaces the image data of the current frame with a second value. The first value is set to a value causing the pixel to respond at a relatively higher speed without the occurrence of the excessive brightness. Without avoiding the deterioration of the image, it is possible to drive a liquid crystal display apparatus including areas whose response speeds are different from each other coexist in the pixel, such as a liquid crystal display apparatus of vertically aligned mode and normally black mode.
    Type: Grant
    Filed: February 1, 2012
    Date of Patent: January 1, 2013
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Makoto Shiomi, Kazunari Tomizawa, Koichi Miyachi, Tomoo Furukawa
  • Patent number: 8339344
    Abstract: A display device which exhibits functional effects in which color separation between sub-pixels constituting a pixel is hardly recognized and white line display is easily recognized as one line, in enlargement of the color reproduction range in image display using multi-primary colors, and thereby improves display quality, and provides a liquid crystal display device including such a display device. The display device displays an image constituted by pixels each including sub-pixels of four or more colors, wherein the pixels constituting the display device mainly include a pixel arranging a sub-pixel of a color having the highest brightness value in a central region of the pixel.
    Type: Grant
    Filed: April 12, 2011
    Date of Patent: December 25, 2012
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Yoshihiro Okada, Kazunari Tomizawa, Kenji Nakamura, Shoji Okazaki
  • Patent number: 8339423
    Abstract: An image display period of a first sub frame of an N-th frame is arranged to partly overlap the image display period of the second sub frame of the N-th frame and the image display period of a second sub frame of the (N?1)-th frame. Grayscale display voltages with which pixels that are horizontally or vertically neighbored are charged are arranged to have inverse polarities, and the polarity of the grayscale display voltage charging each pixel is reversed in each frame. Furthermore, neighboring data signal lines are short-circuited each time the polarity of the grayscale display voltage output to each data signal line is reversed.
    Type: Grant
    Filed: August 18, 2006
    Date of Patent: December 25, 2012
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Kazunari Tomizawa, Yoshihiro Okada
  • Publication number: 20120313981
    Abstract: A display device (100) according to the present invention includes a pixel defined by a plurality of sub pixels. The plurality of sub pixels are a red sub pixel (R) to display red, a green sub pixel (G) to display green, a blue sub pixel (B) to display blue, and a yellow sub pixel (Ye) to display yellow. When an input signal corresponding to green of the sRGB color space is externally input, the display device (100) according to the present invention provides display by use of the green sub pixel (G) and also the yellow sub pixel (Ye). According to the present invention, a multiple primary color display device which suppresses decline of the display quality when an input signal corresponding to green of the sRGB color space is externally input is provided.
    Type: Application
    Filed: February 8, 2011
    Publication date: December 13, 2012
    Applicant: SHARP KABUSHIKI KAISHA
    Inventors: Shun Ueki, Kohzoh Nakamura, Kazunari Tomizawa, Tomohiko Mori, Yuichi Yoshida
  • Publication number: 20120281033
    Abstract: A liquid crystal display device (100) according to the present invention includes a liquid crystal display panel (10) and a driving circuit (20) that supplies display signals to a plurality of subpixels of the liquid crystal display panel (10). The plurality of subpixels are a red subpixel (R), a green subpixel (G), a blue subpixel (B), and a yellow subpixel (Ye). When achromatic colors of at least some gray levels among all gray levels are to be displayed by the pixel, display signals which are supplied to a first subpixel group composed of certain two subpixels are display signals of the same grayscale level, whereas display signals which are supplied to a second subpixel group composed of the other two subpixels are display signals of a different grayscale level from the grayscale level of the display signals supplied to the first subpixel group. The first subpixel group includes the yellow subpixel (Ye), and the second subpixel group includes the blue subpixel (B).
    Type: Application
    Filed: January 6, 2011
    Publication date: November 8, 2012
    Applicant: SHARP KABUSHIKI KAISHA
    Inventors: Yuichi Yoshida, Kazunari Tomizawa, Tomohiko Mori
  • Patent number: 8294739
    Abstract: In one embodiment of the present invention, a signal conversion circuit is disclosed which is suitably used in a multiprimary liquid crystal display device, and a multiprimary liquid crystal display device having such a signal conversion circuit. A signal conversion circuit according to one embodiment of the present invention is for use in a multiprimary liquid crystal display device, and converts an input video signal to a multiprimary signal corresponding to four or more primary colors. When generating a multiprimary signal for displaying dark skin, the signal conversion circuit according to an embodiment of the present invention applies a conversion to the video signal so that a color difference ?u?v?=((u??u60?)2+(v??v60?)2) is 0.
    Type: Grant
    Filed: November 20, 2007
    Date of Patent: October 23, 2012
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Kazunari Tomizawa, Tomohiko Mori, Shun Ueki, Takao Muroi
  • Publication number: 20120229529
    Abstract: A multiple primary color display device according to the present invention includes a pixel defined by a plurality of sub pixels. The plurality of sub pixels include a first sub pixel to display a first color having a first hue, a second sub pixel to display a second color having a second hue, a third sub pixel to display a third color having a third hue, and a fourth sub pixel to display a fourth color having a fourth hue. When a color represented by the input signal is changed from black to white via a color of a prescribed hue, luminance levels of the plurality of sub pixels are set such that the luminance level of each of the first sub pixel, the second sub pixel and the third sub pixel is started to be increased without increasing the luminance level of the fourth sub pixel and such that the luminance level of the third sub pixel is increased at a lower rate than that of the luminance level of each of the first sub pixel and the second sub pixel.
    Type: Application
    Filed: November 22, 2010
    Publication date: September 13, 2012
    Applicant: SHARP KABUSHIKI KAISHA
    Inventors: Kazunari Tomizawa, Yuichi Yoshida, Akiko Sato
  • Publication number: 20120206326
    Abstract: A liquid crystal display device according to the present invention comprises a pixel including a plurality of sub pixels. The plurality of sub pixels include a red sub pixel (R), a green sub pixel (G), a blue sub pixel (B), a yellow sub pixel (Ye) and a cyan sub pixel (C). The aperture area size of one of the cyan sub pixel (C) and the blue sub pixel (B) is larger than the aperture area size of any of the other of the cyan (C) and blue (B) sub pixels, the green sub pixel (G) and the yellow sub pixel (Ye); and the aperture area size of the red sub pixel (R) is larger than the aperture area size of any of the other of the cyan (C) and blue (B) sub pixels, the green sub pixel (G), and the yellow sub pixel (Ye).
    Type: Application
    Filed: October 26, 2010
    Publication date: August 16, 2012
    Applicant: SHARP KABUSHIKI KAISHA
    Inventors: Kohzoh Nakamura, Shun Ueki, Kazunari Tomizawa, Tomohiko Mori, Yuichi Yoshida
  • Publication number: 20120206507
    Abstract: A color conversion circuit converts a three-primary-color signal PS0 to a 5-color signal PS5, and includes (i) a color component extraction module that generates, by performing isochromatic conversion, a 7-color signal PS2 made up of 7 color components equivalent in terms of color to color components d1 through d5 of the 5-color signal PS5, and (ii) a matrix operation module that generates color components of the 5-color signal by performing linear combination of the color components of the 7-color signal. With this, it is possible to realize a color conversion circuit by which colors represented by a signal after conversion can be adjusted using intuitively-understandable parameters.
    Type: Application
    Filed: April 24, 2012
    Publication date: August 16, 2012
    Applicant: Sharp Kabushiki Kaisha
    Inventors: Kazunari TOMIZAWA, Kozo NAKAMURA
  • Patent number: 8243212
    Abstract: When dividing one frame into a plurality of sub-frames to carry out image display, in a gradation range which is able to be displayed using only sub-frames other than the last sub-frame (for example, luminance ½ or less in the case of two-part division, and luminance ¾ or less in the case of four-part division), the luminance of the last sub-frame is set as the minimum luminance, and luminance display is carried out using the other sub-frames.
    Type: Grant
    Filed: February 15, 2006
    Date of Patent: August 14, 2012
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Kazunari Tomizawa, Takeshi Kumakura
  • Patent number: 8243105
    Abstract: The display device of an embodiment of the present invention includes a display section which includes a pixel having a plurality of sub pixels and displays an image whose luminance is based on a luminance gradation of an inputted display signal, wherein the display section is arranged so that an integral value obtained by carrying out the following steps (a) to (d) is not more than 0.0202, the step (a) of measuring surface luminance of the display section and oblique luminance of the display section viewed at 60° from a front direction of the display section, the step (b) of standardizing the front luminance and the oblique luminance so as to calculate front standardized brightness x and oblique standardized brightness, the step (c) of determining n of x^(n/2.2) so that an integral value of a difference between x^(n/2.
    Type: Grant
    Filed: March 10, 2006
    Date of Patent: August 14, 2012
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Kazunari Tomizawa, Tomohiko Mori, Shinji Horino, Makoto Shiomi
  • Patent number: 8233007
    Abstract: A display device using a number n of primary colors (where n is a natural number that is equal to or greater than four) includes a video signal converting section that receives an m-primary-color signal representing a number m of primary colors (where is m is also a natural number that is smaller than n) and that converts the m-primary-color signal into an n-primary -color signal representing the n primary colors. The n primary colors include a color that is complementary to a particular one of the m primary colors. The video signal converting section generates the n-primary-color signal such that if a color component representing the particular primary color of the m-primary-color signal has a negative level, the complementary primary color has an increased luminance and the other non-complementary primary colors have decreased luminances compared to a situation where the color component representing the particular primary color is zero.
    Type: Grant
    Filed: July 30, 2007
    Date of Patent: July 31, 2012
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Kazunari Tomizawa, Shun Ueki
  • Patent number: 8212753
    Abstract: A liquid crystal display device includes a pixel defined by at least four sub-pixels. The sub-pixels include at least one sub-pixel belonging to a first group and at least one sub-pixel belonging to a second group, the sub-pixel of the second group being different from that of the first group. The luminances of the sub-pixels are set such that if the colors represented by the pixel change from black into white while being kept achromatic, the first group of sub-pixel starts to increase in luminance first, and the second group of sub-pixel starts to increase in luminance when the luminance of the first group of sub-pixel reaches a predetermined value.
    Type: Grant
    Filed: November 24, 2006
    Date of Patent: July 3, 2012
    Assignee: Sharp Kabushiki Kaisha
    Inventor: Kazunari Tomizawa
  • Publication number: 20120162545
    Abstract: A liquid crystal display apparatus includes a plurality of areas in which response speeds greatly different from each other coexist in a pixel. A first replacement process section replaces the image data of the desired target frame with a first gradation, when a gradation transition from a current frame to a desired target frame corresponds to the above gradation transition. A second replacement process section replaces the image data of the current frame with a second value. The first value is set to a value causing the pixel to respond at a relatively higher speed without the occurrence of the excessive brightness. Without avoiding the deterioration of the image, it is possible to drive a liquid crystal display apparatus including areas whose response speeds are different from each other coexist in the pixel, such as a liquid crystal display apparatus of vertically aligned mode and normally black mode.
    Type: Application
    Filed: February 1, 2012
    Publication date: June 28, 2012
    Inventors: Makoto Shiomi, Kazunari Tomizawa, Koichi Miyachi, Tomoo Furukawa
  • Patent number: 8194019
    Abstract: A color conversion circuit converts a three-primary-color signal PS0 to a 5-color signal PS5, and includes (i) a color component extraction module that generates, by performing isochromatic conversion, a 7-color signal PS2 made up of 7 color components equivalent in terms of color to color components d1 through d5 of the 5-color signal PS5, and (ii) a matrix operation module that generates color components of the 5-color signal by performing linear combination of the color components of the 7-color signal. With this, it is possible to realize a color conversion circuit by which colors represented by a signal after conversion can be adjusted using intuitively-understandable parameters.
    Type: Grant
    Filed: March 17, 2005
    Date of Patent: June 5, 2012
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Kazunari Tomizawa, Kozo Nakamura
  • Publication number: 20120113379
    Abstract: A liquid crystal display device (100) according to the present invention comprises the steps of: providing a liquid crystal display panel (200), which includes an active-matrix substrate, a counter substrate, and a vertical alignment liquid crystal layer interposed between the active-matrix substrate and the counter substrate; if an achromatic color should be represented, obtaining the chromaticity of the liquid crystal display panel (200) when viewed straight on with respect to each grayscale level and determining a range in which the chromaticity of the liquid crystal display panel (200) when viewed obliquely is adjustable by changing the luminances of respective blue subpixels belonging to the two pixels within their adjustable range; and setting the luminances of the blue subpixels so that the chromaticity of the liquid crystal display panel when viewed obliquely becomes as close to the chromaticity of the liquid crystal display panel when viewed straight on as possible within the adjustable range with re
    Type: Application
    Filed: July 20, 2010
    Publication date: May 10, 2012
    Applicant: SHARP KABUSHIKI KAISHA
    Inventors: Kazunari Tomizawa, Yuichi Yoshida, Tomohiko Mori
  • Patent number: 8134528
    Abstract: A liquid crystal display apparatus includes a plurality of areas in which response speeds greatly different from each other coexist in a pixel. A first replacement process section replaces the image data of the desired target frame with a first gradation, when a gradation transition from a current frame to a desired target frame corresponds to the above gradation transition. A second replacement process section replaces the image data of the current frame with a second value. The first value is set to a value causing the pixel to respond at a relatively higher speed without the occurrence of the excessive brightness. Without avoiding the deterioration of the image, it is possible to drive a liquid crystal display apparatus including areas whose response speeds are different from each other coexist in the pixel, such as a liquid crystal display apparatus of vertically aligned mode and normally black mode.
    Type: Grant
    Filed: February 22, 2008
    Date of Patent: March 13, 2012
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Makoto Shiomi, Kazunari Tomizawa, Koichi Miyachi, Tomoo Furukawa