Patents by Inventor Mitsutaka Okita
Mitsutaka Okita 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: 7864156Abstract: A liquid crystal display device includes a liquid crystal display panel which periodically performs graduation display and non-graduation display, a backlight which illuminates the liquid crystal display panel, and a light source control circuit which sets an illumination period that allows illumination of the backlight for the gradation display and drives the backlight unit during the illumination period. The light source control circuit is configured to drive the backlight intermittently during the illumination period in limiting the luminance of the backlight.Type: GrantFiled: May 29, 2007Date of Patent: January 4, 2011Assignee: Toshiba Matsushita Display Technology Co., Ltd.Inventors: Mitsutaka Okita, Kazuhiro Nishiyama, Shigesumi Araki
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Patent number: 7817233Abstract: In an embodiment of the invention for an OCB (Optically Compensated Bend)-mode liquid-crystal display (LCD) device, retardation and/or a predetermined voltage range, from which a voltage applied to pixels in a viewing area is selected, is set for the each pixel or for the pixels in each region of the viewing area such that: the luminance on each pixel monotonously increases or decreases with increase of voltage in the predetermined voltage range; the luminance in central portion of the viewing area becomes minimum at black displaying.Type: GrantFiled: December 27, 2006Date of Patent: October 19, 2010Assignee: Toshiba Matsushita Display Technology Co., Ltd.Inventors: Mitsutaka Okita, Kazuhiro Nishiyama, Daiichi Suzuki, Shigesumi Araki
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Patent number: 7786969Abstract: In an OCB liquid crystal display device, a gradation voltage of a video signal is set to be lower than a black display optimum voltage, and a reverse transition prevention voltage is set to be higher than the black display optimum voltage and to be lower than a maximum applied voltage, and as the gradation voltage of the video signal becomes low, the reverse transition prevention voltage is set to be high.Type: GrantFiled: November 28, 2006Date of Patent: August 31, 2010Assignee: Toshiba Matsushita Display Technology Co., Ltd.Inventors: Shigesumi Araki, Kazuhiro Nishiyama, Mitsutaka Okita, Daiichi Suzuki
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Patent number: 7733322Abstract: A liquid crystal display device includes a liquid crystal display panel having pixels, a light source which illuminates the display panel, and a control unit which controls the display panel and the light source. The control unit includes an insertion unit which causes the pixel to store a first voltage corresponding to a video signal in a first period within one frame period and to store a second voltage corresponding to a non-video signal in a second period that follows the first period, and a driving unit which enables the light source at least in a period corresponding to the first period in which the first voltage is held in the pixel, and disables the light source in a period corresponding to the second period in which the second voltage is held in the pixel, and is configured to set the first and second voltages at different independent values.Type: GrantFiled: November 29, 2006Date of Patent: June 8, 2010Assignee: Toshiba Matsushita Display Technology Co., Ltd.Inventors: Shigesumi Araki, Kazuhiro Nishiyama, Mitsutaka Okita, Daiichi Suzuki
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Patent number: 7623202Abstract: It is possible to eliminate the blue tone in the black color display in the OCB liquid crystal display device. A liquid crystal display cell (110) includes an opposing substrate (130) having an opposing electrode (Ecom), an array substrate (120) having pixel electrodes of the respective colors (dpixR, dpixG, dpixB), a liquid crystal layer (140) arranged in a bend-arrangement and sandwiched between the opposing substrate (130) and the array substrate (120), and red, green, and blue filter layers (CF(R), CF(G), CF(B)) arranged on one of the substrates. The maximum voltage is applied when performing black color display on the display screen. At least the maximum voltage of the pixel electrode for blue color dpixB applied to the opposing electrode (Ecom) is made different from the maximum voltage of the pixel electrodes of the other colors applied to the opposing electrode (Ecom).Type: GrantFiled: December 8, 2004Date of Patent: November 24, 2009Assignee: Toshiba Matsushita Display Technology Co., LtdInventors: Shigesumi Araki, Kazuhiro Nishiyama, Mitsutaka Okita, Daiichi Suzuki
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Patent number: 7609340Abstract: To reduce the blue tone in the black display of the OCB liquid crystal display device. A liquid crystal display cell (11) includes: an opposing substrate (130) having an opposing electrode (Ecom); an array substrate (120) having a pixel electrode Dpix for each color; a liquid crystal layer (140) arranged in a bend arrangement located between the opposing substrate (120) and the array substrate (120); and red, green, and blue filter layers arranged on one of the substrates. The opposing electrode has a film thickness tB of the portion Ecom (B) corresponding to the blue filter layer, which thickness is set so as to have the minimum value in the range 380 nm to 480 nm in the spectrum of the front reflectance and satisfy the following: 100 nm<tB?140 nm.Type: GrantFiled: October 21, 2004Date of Patent: October 27, 2009Assignee: Toshiba Matsushita Display Technology Co., Ltd.Inventors: Daiichi Suzuki, Kazuhiro Nishiyama, Mitsutaka Okita, Shigesumi Araki
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Publication number: 20090066899Abstract: A liquid crystal display device includes a liquid crystal display panel to which an OCB mode is applied, and an optical compensation element which optically compensates a retardation of the liquid crystal layer in a predetermined display state in which a voltage is applied to the liquid crystal layer. The optical compensation element includes a polarizer, a first retardation plate which is disposed between the polarizer and the liquid crystal display panel and in which discotic liquid crystal molecules are fixed in a state in which the discotic liquid crystal molecules are hybrid-aligned along a normal direction, and a second retardation plate which is disposed between the polarizer and the first retardation plate and has wavelength dispersion characteristics which are opposite to wavelength dispersion characteristics of an in-plane retardation in the liquid crystal layer.Type: ApplicationFiled: November 13, 2008Publication date: March 12, 2009Inventors: Mitsutaka OKITA, Kazuhiro NISHIYAMA, Shigesumi ARAKI
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Publication number: 20090027576Abstract: A device includes a first substrate including a pixel electrode and an underlayer electrode a part of which is opposed to the pixel electrode, a second substrate including a counter-electrode which is opposed to the pixel electrode, and a layer which is held between the first and the second substrate, and which is in a first state prior to power-on and transitions to a second state, at a time of a display operation, wherein the pixel electrode includes a first part that passes light and a second part that reflects light, the second part includes a projection which is opposed to the counter-electrode, and a transverse electric field generating section, which is provided near the projection so as to generate a transverse electric field between the underlayer electrode and the second part, is disposed at an end portion of the second part, which is opposed to the underlying electrode.Type: ApplicationFiled: July 21, 2008Publication date: January 29, 2009Inventors: Tetsuo FUKAMI, Mitsutaka OKITA, Kenji NAKAO
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Publication number: 20090002609Abstract: A liquid crystal display device having a reflective part and a transmissive part in each of a plurality of pixels which are arrayed in a matrix, includes a liquid crystal display panel which is configured such that a liquid crystal layer is held between a pair of substrates, and to which an OCB mode is applied, and a pair of optical elements which are disposed on outer surfaces of the liquid crystal display panel, respectively, and optically compensate a retardation of the liquid crystal layer in a predetermined display state in which a voltage is applied to the liquid crystal layer, wherein the optical element is configured to include a circular polarization element including a polarizer and a first retardation plate which is disposed between the polarizer and the liquid crystal display panel and imparts a retardation of 1/4 wavelength, and a second retardation plate which is disposed between the circular polarization element and the liquid crystal layer, and has refractive index anisotropy with a major axisType: ApplicationFiled: May 15, 2008Publication date: January 1, 2009Inventors: Mitsutaka Okita, Kazuhiro Nishiyama, Shigesumi Araki, Emi Higano
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Publication number: 20080291372Abstract: A transflective liquid crystal display device includes a liquid crystal display panel which is configured such that a liquid crystal layer is held between a pair of substrates, and to which an OCB mode is applied, and a pair of optical elements which are disposed on outsides of the liquid crystal layer, and optically compensate a retardation of the liquid crystal layer in a predetermined display state in which a voltage is applied to the liquid crystal layer, wherein the optical element is configured to include a circular polarization element including a polarizer and a first retardation plate which imparts a retardation of ΒΌ wavelength, and the first retardation plate has such wavelength dispersion characteristics as to establish a relationship, ?1<1, where ?1 is a ratio of an in-plane retardation Re430 at a wavelength of 430 nm to an in-plane retardation Re550 at a wavelength of 550 nm.Type: ApplicationFiled: May 15, 2008Publication date: November 27, 2008Inventors: Emi HIGANO, Kazuhiro Nishiyama, Mitsutaka Okita, Shigesumi Araki
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Patent number: 7443468Abstract: A liquid crystal display cell (110) includes: an opposing substrate (130) having an opposing electrode (Ecom); an array substrate (120) having a pixel electrode Dpix for each color; a liquid crystal layer (140) arranged in a bend arrangement located between the opposing substrate (120) and the array substrate (120); and red, green, and blue filter layers (CF(R), CF(G), CF(B)) arranged on one of the substrates. Distances (dB, dG, dR) between the pixel electrodes of the respective colors (dpixR, dpixG, dpixB) and the opposing electrode (Ecom) are set as follows: dB<dR, dB.Type: GrantFiled: October 21, 2004Date of Patent: October 28, 2008Assignee: Toshiba Matsushita Display Technology Co., Ltd.Inventors: Mitsutaka Okita, Kazuhiro Nishiyama, Daiichi Suzuki, Shigesumi Araki
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Publication number: 20080211787Abstract: A liquid crystal display apparatus includes a display panel configured to have a plurality of scanning lines for which liquid crystal display elements each containing an optical input device and a display pixel are arranged, respectively, a backlight configured to be arranged facing the display panel to illuminate the display panel, and a control part configured to control writing into the display pixel and reading of a detection signal of the optical input device, wherein the control part displays an external light detection image substantially shielding light from the backlight on the display pixels throughout a first period of a frame period, and displays a display image on the display pixels throughout a second period of the frame period.Type: ApplicationFiled: February 15, 2008Publication date: September 4, 2008Inventors: Kenji Nakao, Yasuyuki Tsuji, Mitsutaka Okita, Shigesumi Araki
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Publication number: 20080074592Abstract: A liquid crystal display apparatus includes a display panel configured to be formed by arranging pixels like a matrix, a light source configured to light the display panel, and a driving control means for controlling the display panel, wherein the pixels are transreflective type liquid crystal pixels having a reflective part and a transmissive part driven independently, and the driving control means is configured to separately control non-image periods of the reflective part and transmissive part.Type: ApplicationFiled: July 25, 2007Publication date: March 27, 2008Inventors: Shigesumi Araki, Kazuhiro Nishiyama, Mitsutaka Okita
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Publication number: 20080068317Abstract: A display apparatus includes a video signal converter unit which converts input video signals of n colors (n is an integer equal to or larger than 2) into converted video signals of at least (n+1) colors, a video signal generator unit which, on the basis of the input video signal of at least one color, generates converted video signals of new (n+1) colors with the luminance of two or more converted video signals being improved, a display panel which displays (n+1) images sequentially on the basis of the converted video signals of the new (n+1) colors, and a backlight which switches between light sources of (n+1) colors for illumination sequentially in accordance with the images displayed on the display panel.Type: ApplicationFiled: June 18, 2007Publication date: March 20, 2008Inventors: Shigesumi Araki, Kazuhiro Nishiyama, Mitsutaka Okita
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Publication number: 20080049005Abstract: A liquid crystal display device includes a reflective display part and a transmissive display part in each of a plurality of matrix-arrayed pixels. The liquid crystal display device includes a liquid crystal display panel which is configured such that a liquid crystal layer is held between a pair of substrates and gradation display is performed in accordance with a pixel voltage which is applied to the liquid crystal layer of each pixel, a backlight which illuminates the liquid crystal display panel, a sensor unit which detects brightness of ambient light, and a voltage setting unit which sets the pixel voltage relative to each of input gradation levels, on the basis of the brightness that is detected by the sensor unit.Type: ApplicationFiled: July 11, 2007Publication date: February 28, 2008Inventors: Mitsutaka Okita, Kazuhiro Nishiyama, Shigesumi Araki, Emi Kisara
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Publication number: 20080049178Abstract: A liquid crystal display device includes an OCB mode liquid crystal display panel, and an optical compensation element which is disposed outside of the liquid crystal display layer. The optical compensation element includes a polarizer plate, a first retardation plate which is disposed between the polarizer plate and the liquid crystal layer, and a second retardation plate which is disposed between the polarizer plate and the first retardation plate and has a biaxial refractive index anisotropy. The optical compensation element compensates a difference of a polarization state that differs between azimuth directions of light passing through the liquid crystal layer and compensates a shift of the polarization state of light, which passes through the retardation plate, from an azimuth direction of an absorption axis of the polarizer plate.Type: ApplicationFiled: July 26, 2007Publication date: February 28, 2008Inventors: Emi Kisara, Kazuhiro Nishiyama, Mitsutaka Okita, Shigesumi Araki
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Publication number: 20070285403Abstract: A display apparatus includes a display panel in which pixels are arranged in a matrix, a light source which is provided to face the display panel and illuminates one face of the display panel, selecting means which is provided between the display panel and the light source and is configured to transmit or reflect light, and control means for generating a frame which is time-shared by a transmissive display state produced by light from the light source, transmissive control of the selecting means, and display control of the display panel, and a reflective display state produced by reflective control of the selecting means and display control of the display panel.Type: ApplicationFiled: June 11, 2007Publication date: December 13, 2007Inventors: Shinichi Aota, Kazuhiro Nishiyama, Mitsutaka Okita, Shigesumi Araki
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Publication number: 20070273678Abstract: A liquid crystal display device includes a liquid crystal display panel which periodically performs graduation display and non-graduation display, a backlight which illuminates the liquid crystal display panel, and a light source control circuit which sets an illumination period that allows illumination of the backlight for the gradation display and drives the backlight unit during the illumination period. The light source control circuit is configured to drive the backlight intermittently during the illumination period in limiting the luminance of the backlight.Type: ApplicationFiled: May 29, 2007Publication date: November 29, 2007Inventors: Mitsutaka Okita, Kazuhiro Nishiyama, Shigesumi Araki
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Publication number: 20070229447Abstract: Common signals VCOM during a black voltage writing period are set to be larger than common signals VCOM during a video writing period. The common voltage signals VCOM is VmH or VmL during the black voltage writing periods. The common voltage signals VCOM is VcH or VcL during video writing periods and video holding periods. The polarity of the common voltage signals VCOM is inverted alternately from frame to frame. A backlight is extinguished in the black voltage writing period.Type: ApplicationFiled: March 21, 2007Publication date: October 4, 2007Applicant: Toshiba Matsushita Display Technology Co., Ltd.Inventors: Hiroshi Takahara, Kenji Nakao, Kazuhiro Nishiyama, Yukio Tanaka, Shigesumi Araki, Mitsutaka Okita, Tetsuo Fukami
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Publication number: 20070222729Abstract: A liquid crystal display device includes liquid crystal pixels which perform display of different color components, a driver which drives the liquid crystal pixels according to a video signal which expresses gradations of the color components, and a video signal processor which corrects the video signal to keep a color gamut substantially constant in a range from a maximum gradation to a specified intermediate gradation.Type: ApplicationFiled: March 21, 2007Publication date: September 27, 2007Inventors: Kazuhiro Nishiyama, Mitsutaka Okita, Daiichi Suzuki, Shigesumi Araki