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).
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Patent number: 9323103Abstract: The liquid crystal display device (100) of the present invention includes a liquid crystal panel (10) having a plurality of pixels (P), and a backlight (20) having at least one light source (22) that emits light to the liquid crystal panel (10). Each of the plurality of pixels (P) includes four or more sub-pixels (R, G, B, Ye), and the light source unit (22) includes a red light source (22R), a green light source (22G), and a blue light source (22B). According to the present invention, a liquid crystal display device which can perform display of wide color reproduction range with low power consumption is provided.Type: GrantFiled: March 3, 2011Date of Patent: April 26, 2016Assignee: Sharp Kabushiki KaishaInventors: Tomohiko Mori, Kazunari Tomizawa, Makoto Hasegawa, Yuichi Yoshida
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Patent number: 9245471Abstract: A multi-primary-color liquid crystal display device (100) according to the present invention includes a liquid crystal display panel (10) with a pixel made up of red, green, blue and yellow subpixels (R, G, B, Ye) and a signal conversion circuit (20) which converts an input three-primary-color video signal into a four-color video signal. If the three-primary-color video signal supplied to the signal conversion circuit is indicated as (r, g, b) using the grayscale levels r, g and b (each of which is an integer of 0 through 255) of the three primary colors of red, green and blue and if the luminance of the color white displayed by the pixel in response to a three-primary-color video signal indicated as (255, 255, 255) is supposed to be 100%, the signal conversion circuit adjusts the level of the four-color video signal so that when a three-primary-color video signal indicated as (186, 0, 0) is input, the luminance of the color red displayed by the red subpixel becomes equal to or greater than 6.5%.Type: GrantFiled: June 30, 2011Date of Patent: January 26, 2016Assignee: Sharp Kabushiki KaishaInventors: Kazunari Tomizawa, Kohzoh Nakamura
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Patent number: 9230494Abstract: 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: GrantFiled: March 16, 2011Date of Patent: January 5, 2016Assignee: Sharp Kabushiki KaishaInventors: Makoto Hasegawa, Kazunari Tomizawa
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Publication number: 20150325165Abstract: A display device is disclosed, along with a display method capable of displaying an input image having a resolution higher than the resolution of a display panel without degradation in display quality. The display device is a display device for displaying an image with each frame divided into two sub-frames. In the display device, a bright sub-pixel and a dark sub-pixel in each pixel are interchanged every sub-frame, and an input signal has a vertical resolution twice that of a display panel. The display device displays an image corresponding to the input signal by making the sub-frames different from each other in a voltage supplied to each pixel.Type: ApplicationFiled: June 7, 2013Publication date: November 12, 2015Inventors: Tomohiko MORI, Kazunari TOMIZAWA, Makoto HASEGAWA, Yuichi YOSHIDA
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Patent number: 9177512Abstract: 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: GrantFiled: February 8, 2011Date of Patent: November 3, 2015Assignee: Sharp Kabushiki KaishaInventors: Shun Ueki, Kohzoh Nakamura, Kazunari Tomizawa, Tomohiko Mori, Yuichi Yoshida
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Patent number: 9165494Abstract: A signal conversion circuit (20) is used for a multiple-primary color liquid crystal display device (100) which performs color display using four primary colors of red displayed by a red-sub pixel (R), green displayed by green-sub pixel (G), blue displayed by blue-sub pixel (B), and yellow displayed by yellow-sub pixel (Ye), and converts an input three-primary color video signal into a multiple-primary color video signal corresponding to four primary colors. The signal conversion circuit (20) performs signal conversion such that a gray scale level of the yellow-sub pixel (Ye) is higher than a gray scale level of the green-sub pixel (G) in at least some cases from among cases in which a red gray-scale level r, a green gray-scale level g, and a blue gray-scale level b which are displayed by the three-primary color video signal satisfy a relationship of r>g>b.Type: GrantFiled: December 22, 2011Date of Patent: October 20, 2015Assignee: Sharp Kabushiki KaishaInventors: Yuichi Yoshida, Tomohiko Mori, Kazunari Tomizawa, Kohzoh Nakamura, Shun Ueki
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Publication number: 20150263240Abstract: An electronic color-chart device includes plural LEDs with different peak wavelengths and displays images to serve as color references as color charts by making the plural LEDs emit light. In a case where a light emission intensity distribution of each of the plural LEDs is normalized with a maximum intensity being a value of 1, the plural LEDs include plural first LEDs of which at least one is an LED whose full wavelength width at half maximum intensity is 40 nm or narrower and between which a peak interval is 50 nm or narrower and a second LED whose light emission intensity at a wavelength of 555 nm is 0.4 or higher, and whose full wavelength width at half maximum intensity is wider than 40 nm.Type: ApplicationFiled: September 10, 2013Publication date: September 17, 2015Applicant: National University Corporation Shizuoka UniversityInventors: Kazunari Tomizawa, Yoshifumi Shimodaira
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Publication number: 20150235615Abstract: A multi-primary color display device (100) includes: a multi-primary color display panel (10) including a pixel that is defined by a plurality of sub pixels including a red sub pixel (R), a green sub pixel (G), a blue sub pixel (B), and a yellow sub pixel (Ye); and a signal converting circuit (20) converting a three-primary color image signal corresponding to three primary colors into a multi-primary color image signal corresponding to four or more primary colors. The signal converting circuit (20), in a case where a three-primary color image signal representing at least an achromatic color of a half tone is input, performs a signal conversion such that variations in luminance levels of the plurality of sub pixels are equalized.Type: ApplicationFiled: September 2, 2013Publication date: August 20, 2015Inventors: Yuichi Yoshida, Kazunari Tomizawa, Tomohiko Mori, Makoto Hasegawa
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Patent number: 9058783Abstract: This liquid crystal display device (100) includes a pixel defined by a plurality of subpixels that includes red, green, blue and yellow subpixels (R, G, B, Ye). As long as the sum of respective luminances of all of the subpixels but the blue subpixel (B) falls within the range of 0% to 50% while the color displayed by the pixel is changing from the color blue in which the blue subpixel (B) is at the highest grayscale level and the other subpixels are at the lowest grayscale level into the color white in which all of those subpixels are at the highest grayscale level substantially without changing its hue, the yellow subpixel (Ye) starts to increase its grayscale level at a different timing, and/or has its grayscale level increased at a different ratio with respect to an increase in the pixel's luminance, from the red and green subpixels (R, G) do.Type: GrantFiled: August 28, 2012Date of Patent: June 16, 2015Assignee: Sharp Kabushiki KaishaInventors: Kazunari Tomizawa, Yuichi Yoshida, Tomohiko Mori, Makoto Hasegawa
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Publication number: 20150035869Abstract: In a display apparatus having a liquid crystal panel, a change in luminance of the entire display frame when overshoot driving is performed is suppressed, while improving a viewing angle of the liquid crystal panel. A processing unit performs a high gradation display displaying a gradation higher than a gradation of an input image at one of two adjacent pixels, performs a low gradation display displaying a gradation lower than a gradation of an input image at the other of the two adjacent pixels, and switches between the high gradation display and the low gradation display for each pixel every display frame. A correction unit corrects a gradation of a pixel located adjacent to a pixel displayed with a gradation for which predetermined overshoot driving is difficult in the next display frame to a gradation for which overshoot driving stronger than the predetermined overshoot driving is possible.Type: ApplicationFiled: February 13, 2013Publication date: February 5, 2015Inventors: Tomohiko Mori, Kazunari Tomizawa, Makoto Hasegawa, Yuichi Yoshida
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Patent number: 8947476Abstract: A liquid crystal display device includes a liquid crystal display panel and a driving circuit that supplies display signals to a plurality of subpixels of the liquid crystal display panel. The plurality of subpixels are a red subpixel, a green subpixel, a blue subpixel, and a yellow subpixel. 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, and the second subpixel group includes the blue subpixel.Type: GrantFiled: January 6, 2011Date of Patent: February 3, 2015Assignee: Sharp Kabushiki KaishaInventors: Yuichi Yoshida, Kazunari Tomizawa, Tomohiko Mori
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Publication number: 20140253422Abstract: This liquid crystal display device (100) includes a pixel defined by a plurality of subpixels that includes red, green, blue and yellow subpixels (R, G, B, Ye). As long as the sum of respective luminances of all of the subpixels but the blue subpixel (B) falls within the range of 0% to 50% while the color displayed by the pixel is changing from the color blue in which the blue subpixel (B) is at the highest grayscale level and the other subpixels are at the lowest grayscale level into the color white in which all of those subpixels are at the highest grayscale level substantially without changing its hue, the yellow subpixel (Ye) starts to increase its grayscale level at a different timing, and/or has its grayscale level increased at a different ratio with respect to an increase in the pixel's luminance, from the red and green subpixels (R, G) do.Type: ApplicationFiled: August 28, 2012Publication date: September 11, 2014Applicant: SHARP KABUSHIKI KAISHAInventors: Kazunari Tomizawa, Yuichi Yoshida, Tomohiko Mori, Makoto Hasegawa
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Patent number: 8780029Abstract: A multiprimary liquid crystal display device in which deteriorations in display quality caused by the coloration of a gray representation when viewed from an oblique direction are suppressed, and a signal conversion circuit for use in such a multiprimary liquid crystal display device are provided. A signal conversion circuit according to the present invention is for use in a multiprimary liquid crystal display device, the multiprimary liquid crystal display device having a pixel defined by a plurality of subpixels including a red subpixel, a green subpixel, a blue subpixel, and a yellow subpixel, and performing multicolor display by using four or more primary colors to be displayed by the plurality of subpixels, the signal conversion circuit converting an input video signal to a multiprimary signal corresponding to four or more primary colors. When a video signal for the pixel to display a gray color having a normalized luminance of no less than 0.2 and no more than 0.Type: GrantFiled: September 18, 2009Date of Patent: July 15, 2014Assignee: Sharp Kabushiki KaishaInventors: Kozo Nakamura, Shun Ueki, Kazunari Tomizawa, Tomohiko Mori, Yuichi Yoshida
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Patent number: 8773340Abstract: 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: GrantFiled: March 12, 2013Date of Patent: July 8, 2014Assignee: Sharp Kabushiki KaishaInventors: Kazunari Tomizawa, Kozo Nakamura
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Publication number: 20140118423Abstract: Viewing angle characteristics on the entire display surface are improved while suppressing harmful effects such as flicker and banding caused by viewing angle improvement control. A liquid crystal display apparatus (1) includes: a liquid crystal panel (11) which includes a plurality of pixels arranged in a matrix; a drive control unit (24) which performs viewing angle improvement processing by converting a gradation of a video signal input to the pixel; and a processing object determination unit (22) which determines whether or not an image displayed on each of the pixels of the liquid crystal panel (11) is an image having an intermediate color. The drive control unit (24) is configured to perform the viewing angle improvement processing on the pixel determined by the processing object determination unit (22) such that the pixel displays the image having the intermediate color.Type: ApplicationFiled: June 22, 2012Publication date: May 1, 2014Applicant: SHARP KABUSHIKI KAISHAInventors: Makoto Hasegawa, Kazunari Tomizawa, Tomohiko Mori, Yuichi Yoshida
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Patent number: 8675031Abstract: 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: GrantFiled: October 26, 2010Date of Patent: March 18, 2014Assignee: Sharp Kabushiki KaishaInventors: Kohzoh Nakamura, Shun Ueki, Kazunari Tomizawa, Tomohiko Mori, Yuichi Yoshida
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Patent number: 8654116Abstract: 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: GrantFiled: September 12, 2012Date of Patent: February 18, 2014Assignee: Sharp Kabushiki KaishaInventors: Kazunari Tomizawa, Tomohiko Mori, Shun Ueki, Takao Muroi
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Patent number: 8576261Abstract: A liquid crystal display device (100A) of the present invention includes an active matrix substrate (220); a counter substrate (240); and a vertical alignment type liquid crystal layer (260). The liquid crystal display device (100) has a plurality of pixels, each of the pixels including a plurality of subpixels. The plurality of subpixels include a red subpixel (R), a green subpixel (G), and a blue subpixel (B). When each of adjacent two of the plurality of pixels represents an achromatic color at a certain grayscale level, a luminance of a blue subpixel (B) included in one of the two adjacent pixels is different from a luminance of a blue subpixel (B) included in the other of the two adjacent pixels.Type: GrantFiled: December 8, 2009Date of Patent: November 5, 2013Assignee: Sharp Kabushiki KaishaInventors: Yuichi Yoshida, Kazunari Tomizawa, Tomohiko Mori, Kozo Nakamura, Shun Ueki
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Patent number: 8576262Abstract: A liquid crystal device (100A) according to the present invention has first and second pixels (P1 and P2). Each of the first and second pixels (P1 and P2) includes first, second and third subpixels (R, G, and B). When the input signal indicates that each pixel should represent the first color, the luminances of the respective third subpixels (B1 and B2) of the first and second pixels (P1 and P2) are different from each other. But when the input signal indicates that each pixel should represent the second color, the average luminance of the respective third subpixels (B1 and B2) is substantially the same as when the first color is specified, and the luminances of the respective third subpixels (B1 and B2) are substantially equal to each other.Type: GrantFiled: December 25, 2009Date of Patent: November 5, 2013Assignee: Sharp Kabushiki KaishaInventors: Tomohiko Mori, Kazunari Tomizawa, Yuichi Yoshida
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Patent number: 8570351Abstract: A liquid crystal display device (100) according to the present invention includes pixels (P1) and (P2), each of which includes three subpixels (R1, G1, B1) and (R2, G2, B2). When the input signal indicates that a chromatic color should be represented, one of the subpixels (B1 and B2) is turned ON and at least one of the subpixels (R1, R2, G1 and G2) is turned ON, too. If the average luminance of the subpixels (B1 and B2) in a situation where the input signal indicates that the chromatic color should be represented is substantially equal to that of the subpixels (B1 and B2) in another situation where the input signal indicates that an achromatic color should be represented, the luminances of those subpixels (B1 and B2) in the former situation are different from those of the subpixels (B1 and B2) in the latter situation.Type: GrantFiled: December 25, 2009Date of Patent: October 29, 2013Assignee: Sharp Kabushiki KaishaInventors: Tomohiko Mori, Kazunari Tomizawa, Yuichi Yoshida