Patents by Inventor Ikuo Hiyama
Ikuo Hiyama 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: 7898638Abstract: Disclosed herein is a liquid-crystal display device capable of reducing leakage of light under a black state due to scattering from a liquid-crystal layer, and having high-contrast ratio, excellent image quality performance. The liquid-crystal display device comprises: a liquid-crystal panel including one pair of polarizers disposed on one pair of substrates, a liquid-crystal layer held in sandwiched form between the pair of substrates, and a group of electrodes formed on at least one of the pair of substrates for applying an electric field to the liquid-crystal layer; and a light source unit disposed outside the pair of substrates. The liquid-crystal layer includes a liquid-crystal material having an ordinary-light refractive index of at least 1.46, but up to 1.49, an extraordinary-light refractive index of at least 1.54, but up to 1.59, and a mean photoelastic constant of at least 8, but up to 25, and exhibiting a nematic phase.Type: GrantFiled: August 15, 2008Date of Patent: March 1, 2011Assignee: Hitachi Displays, Ltd.Inventors: Yuka Utsumi, Shintaro Takeda, Hiroyuki Kagawa, Daisuke Kajita, Ikuo Hiyama, Kikuo Ono
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Publication number: 20100321607Abstract: A liquid crystal display device includes: a liquid crystal layer which contains a liquid crystal composition; a pair of substrates opposed to each other across the liquid crystal layer; alignment layers placed on liquid crystal layer sides of the pair of substrates, respectively; and polarization plates placed on opposite sides from the liquid crystal layer sides, respectively. The pair of substrates includes a thin-film transistor substrate including a thin-film transistor for controlling molecule alignment of the liquid crystal composition, and a color filter substrate including a color layer containing pixels of different colors. A blue pixel, which is one of the pixels of different colors, is larger in area than any of the pixels of other colors. A loss of light in a short-wavelength range is thus reduced.Type: ApplicationFiled: June 21, 2010Publication date: December 23, 2010Inventors: Yuka UTSUMI, Yasushi Tomioka, Ikuo Hiyama
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Patent number: 7855760Abstract: In a liquid crystal apparatus in which a white light of a fluorescent tube corresponding to a linear light source repeats plural times of diffusions and reflections between a reflection sheet and a diffusion plate, and is thereafter input as a back light to a liquid crystal panel corresponding to a display screen, an object of the invention is to make it possible to secure a brightness uniformity even if the liquid crystal apparatus is thinned. It is possible to prevent a brightness unevenness caused by a short distance from the reflection sheet to the diffusion plate, by preventing a deformation (a deformation which is convex toward the fluorescent tube) of the diffusion plate due to a thermal expansion of the diffusion plate caused by a heat generation of the fluorescent tube, by arranging at least one pin mold hold so as to support a portion near an approximately center of the diffusion plate.Type: GrantFiled: August 14, 2008Date of Patent: December 21, 2010Assignee: Hitachi, Ltd.Inventors: Makoto Tsumura, Akitoyo Konno, Yoshifumi Sekiguchi, Ikuo Hiyama, Daisuke Kajita
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Publication number: 20100309110Abstract: A light unit which includes a plurality of light-emitting diode (LED) light sources arranged in parallel, a light-guiding member arranged on said LED light sources, a light reflecting part for reflecting light from said LED light sources forward, a light diffusion part for outgoing light from the surface of said light-guiding member to outside, and an optical path changing part arranged above said light-diffusion part, wherein a side of said light-guiding member that faces said light diffusion part is flat.Type: ApplicationFiled: August 17, 2010Publication date: December 9, 2010Inventors: Masaya ADACHI, Ikuo HIYAMA, Makoto TSUMURA, Shusuke ENDO
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Patent number: 7828473Abstract: A liquid crystal display (LCD) panel with a backlight module including a light-emitting diode (LED)-based illumination device is disclosed. The illumination device includes more than one LED of the waveguide type for use as a light source of the backlight. The LCD panel includes a pair of substrates, a liquid crystal (LC) layer interposed between these substrates, and a polarization plate. Output light of the LED is linearly polarized in advance. A waveguide is arranged for giving off polarized light components from the LED only in a chosen direction to thereby permit incidence in parallel with a polarized light transmission direction of the LCD polarizer plate. The LED is amounted and arranged so that the polarized light transmission direction of the polarizer plate is the same as the polarization direction through an optical system associated therewith.Type: GrantFiled: November 3, 2005Date of Patent: November 9, 2010Assignee: Hitachi Displays, Ltd.Inventors: Toshiaki Tanaka, Hiroki Kaneko, Ikuo Hiyama
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Patent number: 7824049Abstract: An illumination device has a plurality of sealing structures each including a light-emitting diode, sealed by a high refractive index transparent material member which is further sealed by a low refractive index transparent material member. To increase a divergence angle of light radiation, the portion of the high refractive index transparent material member which covers an upper surface of the light-emitting diode is structured so as to satisfy a relation H>(L/2)/tan {sin?1(n1/n2)}, where H represents a thickness of the high refractive index transparent material member measured at the central portion of the upper surface of the light-emitting diode, L represents the length of one side of the upper surface of the light-emitting diode, n1 represents the refractive index of the high refractive index transparent material member and n2 represents the refractive index of the low refractive index transparent material member.Type: GrantFiled: December 10, 2007Date of Patent: November 2, 2010Assignee: Hitachi Displays, Ltd.Inventors: Hiroki Kaneko, Toshiaki Tanaka, Ikuo Hiyama, Hiroshi Sasaki, Yoshifumi Sekiguchi
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Publication number: 20100271575Abstract: Provided is a liquid crystal display device including: a substrate (13) including a polarizing layer (11) on a light-input side; a substrate (14) including a polarizing layer (12) on another side, the polarizing layers having absorption axes substantially perpendicular; a liquid crystal layer (15) in which a liquid-crystal-molecule is aligned to be substantially horizontal to the substrates. In a case where an absorption axis of the polarizing layer (11) and an optical axis of the liquid crystal layer are substantially perpendicular, the optical compensating members (17 and 18) may be provided between the polarizing layer (11) and the liquid crystal layer; the absorption axis of the polarizing layer (11) and a slow axis of the optical compensating members are substantially perpendicular; each pixel satisfies nx?ny?nz; thickness-direction retardation for pixels of one color is different from other colors; and the thickness-direction retardation for red pixels is larger than 0 nm.Type: ApplicationFiled: April 28, 2010Publication date: October 28, 2010Inventors: Kentaro Ojima, Daisuke Kajita, Ikuo Hiyama, Masahiro Ishii, Yasushi Tomioka
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Patent number: 7817226Abstract: A liquid crystal display device comprises: a first substrate having a first polarization layer on a light incident side; a second substrate having a second polarization layer on a light outgoing side; a liquid crystal layer disposed between the first and the second substrates; a first birefringent film disposed between the first and the second polarization layers; a second birefringent film disposed between the first birefringent film and the second polarization layer; and wherein the liquid crystal layer has a property that a refractive index anisotropy is induced in it by an electric field applied between the pixel electrodes and the common electrode; wherein in-plane retarded phase axes of the first and the second birefringent films form an angle of from 88 degrees to 92 degrees with the first polarization layer; wherein the first birefringent films have Nz coefficients greater than 0.5 and smaller than 0.5, respectively.Type: GrantFiled: January 24, 2008Date of Patent: October 19, 2010Assignee: Hitachi Displays, Ltd.Inventors: Daisuke Kajita, Ikuo Hiyama, Shintaro Takeda
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Publication number: 20100245726Abstract: A liquid crystal display device comprising a liquid crystal panel having a cell 15 and polarizing plates 11, 12; wherein a liquid crystal molecule is rotated in parallel to the cell 15, the polarizing plate 12 has a multiple polarizer layer formed thereon, the multiple player having a first polarizer layer having a higher polarization degree with respect to a light from a forward direction than a polarization degree with respect to a light from a oblique direction and a second polarizer layer having a higher polarization degree with respect to a light from a oblique direction than a polarization degree with respect to a light from a forward direction, and an average elastic constant of a splay elastic constant K1, a twist elastic constant K2, and a bend elastic constant K3 of liquid crystal material is equal to 10×10?12 N or larger and satisfies a relationship of K1/K2<=1.5.Type: ApplicationFiled: February 19, 2010Publication date: September 30, 2010Inventors: Yuka UTSUMI, Shintaro Takeda, Ikuo Hiyama, Kikuo Ono
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Patent number: 7784986Abstract: A light unit which includes a plurality of light-emitting diode (LED) light sources arranged in parallel, a light-guiding member arranged on said LED light sources, a light reflecting part for reflecting light from said LED light sources forward, a light diffusion part for outgoing light from the surface of said light-guiding member to outside, and an optical path changing part arranged above said light-diffusion part, wherein a side of said light-guiding member that faces said light diffusion part is flat.Type: GrantFiled: April 19, 2005Date of Patent: August 31, 2010Assignee: Hitachi, Ltd.Inventors: Masaya Adachi, Ikuo Hiyama, Makoto Tsumura, Shusuke Endo
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Publication number: 20100165250Abstract: A liquid crystal display device having a direct backlight which uses a high-bright light source achieves both of a high efficiency and thin uniformity. In a liquid crystal display device which includes a liquid crystal panel, and a backlight unit which is arranged on a side of the liquid crystal panel opposite to a display screen of the liquid crystal panel, the backlight unit includes a housing, a plurality of light sources arranged in the inside of the housing, and a diffusion plate which is arranged between the plurality of light sources and the liquid crystal panel, the diffusion plate includes a plurality of light blocking regions at positions corresponding to the plurality of respective light sources, and the light blocking region at a center portion of the housing and the light blocking region at an edge portion of the housing exhibits transmissivities different from each other.Type: ApplicationFiled: March 9, 2010Publication date: July 1, 2010Inventors: Yoshihiro Imajo, Yoshifumi Sekiguchi, Hitoshi Taniguchi, Ikuo Hiyama
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Publication number: 20100165246Abstract: An illuminating device capable of being produced at low costs and irradiating rays of light uniformly to a liquid crystal panel. The illuminating device has a plurality of LED packages each having LED's and a lens, the LED packages being congregated on a plane in a large area. Each of the LED packages includes at least four LED's corresponding to LED's for emitting at least red, green and blue, and at least two of the LED's in each LED package are positioned symmetrically to the center of the lens and emit the same color.Type: ApplicationFiled: January 27, 2010Publication date: July 1, 2010Inventors: Yoshifumi Sekiguchi, Ikuo Hiyama, Tsunenori Yamamoto, Hiroki Kaneko, Toshiaki Tanaka
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Publication number: 20100165249Abstract: A liquid crystal display device having a direct backlight which uses a high-bright light source achieves both of a high efficiency and thin uniformity. In a liquid crystal display device which includes a liquid crystal panel, and a backlight unit which is arranged on a side of the liquid crystal panel opposite to a display screen of the liquid crystal panel, the backlight unit includes a housing, a plurality of light sources arranged in the inside of the housing, and a diffusion plate which is arranged between the plurality of light sources and the liquid crystal panel, the diffusion plate includes a plurality of light blocking regions at positions corresponding to the plurality of respective light sources, and the light blocking region at a center portion of the housing and the light blocking region at an edge portion of the housing exhibits transmissivities different from each other.Type: ApplicationFiled: March 8, 2010Publication date: July 1, 2010Inventors: Yoshihiro Imajo, Yoshifumi Sekiguchi, Hitoshi Taniguchi, Ikuo Hiyama
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Patent number: 7737930Abstract: A liquid crystal display apparatus that includes a liquid crystal display panel having a liquid crystal layer held between a pair of substrates, a light source whose brightness is controllable, and a normalization processing circuit that converts an image signal to a normalized signal and to a normalization coefficient. In addition, the display apparatus includes an LCD driving circuit that converts the normalized signal to an LCD driving signal for driving the liquid crystal display panel, and a light source driving circuit that converts the normalization coefficient to a light source driving signal for driving the light source. The normalization coefficient is used to set pixel values in a blanking interval of a display screen, and the normalized signal is used to set pixel values in a display area of the display screen.Type: GrantFiled: November 18, 2005Date of Patent: June 15, 2010Assignee: Hitachi, Ltd.Inventors: Tatsuki Inuzuka, Tsunenori Yamamoto, Akitoyo Konno, Ikuo Hiyama
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Patent number: 7733449Abstract: A liquid crystal display of a vertical alignment (VA) mode using a circular polarization plate is provided which can reduce light leak as observed along an oblique direction and achieve a high contrast ratio. The VA mode uses a liquid crystal layer of vertical alignment in an initial alignment state. A film having generally isotropic optical characteristics in an omnidirection is used as a protective film, on a liquid crystal cell side, of first and second polarization plates disposed outside the liquid crystal cell, and first and fourth retardation films have an Nz coefficient smaller than 1.Type: GrantFiled: February 17, 2006Date of Patent: June 8, 2010Assignee: Hitachi Displays, Ltd.Inventors: Shinichiro Oka, Masaya Adachi, Shinichi Komura, Ikuo Hiyama
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Patent number: 7719647Abstract: An IPS-mode liquid-crystal display apparatus for controlling transmission and cutoff of light by applying a cross-directional electric field to liquid-crystal molecules horizontally oriented reduces diagonal luminance rise and coloring at the time of black display by a simple configuration. A configuration is used in which an optical phase compensation member for canceling the double refraction property of a polarization-plate support base material is provided between the liquid-crystal-layer-side support base material of a lower polarizer and a liquid-crystal layer. Or, a configuration is used in which the optical phase compensation for canceling double refraction property of the polarization-plate support base material is provided between the liquid-crystal-layer-side support base material and the liquid-crystal layer.Type: GrantFiled: February 6, 2006Date of Patent: May 18, 2010Assignee: Hitachi Displays, Ltd.Inventors: Daisuke Kajita, Ikuo Hiyama, Masahiro Ishii
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Patent number: 7705930Abstract: A liquid crystal display device having a direct backlight which uses a high-bright light source achieves both of a high efficiency and thin uniformity. In a liquid crystal display device which includes a liquid crystal panel, and a backlight unit which is arranged on a side of the liquid crystal panel opposite to a display screen of the liquid crystal panel, the backlight unit includes a housing, a plurality of light sources arranged in the inside of the housing, and a diffusion plate which is arranged between the plurality of light sources and the liquid crystal panel, the diffusion plate includes a plurality of light blocking regions at positions corresponding to the plurality of respective light sources, and the light blocking region at a center portion of the housing and the light blocking region at an edge portion of the housing exhibits transmissivities different from each other.Type: GrantFiled: June 29, 2007Date of Patent: April 27, 2010Assignees: Hitachi Displays, Ltd., IPS Alpha Technology, Ltd.Inventors: Yoshihiro Imajo, Yoshifumi Sekiguchi, Hitoshi Taniguchi, Ikuo Hiyama
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Patent number: 7684005Abstract: A liquid crystal display apparatus includes a liquid crystal panel having polarizers, and a back light having a light source for illumination of the liquid crystal panel which has a characteristic of spectral transmittance required to satisfy the following equation, x>y>z, when a medium tone display voltage varies in a range between a minimum and maximum voltage for a Blue pixel, where “x” is a value of the transmittance in the panel at a wavelength corresponding to a longest wavelength in a range of wavelengths designated for blue light, “y” is a value of the transmittance in the panel at a wavelength corresponding to a maximum value of the intensity in a range of wavelengths designated for green light, and “z” is a value of the transmittance in the panel at a wavelength corresponding to a maximum value of the intensity in a range of wavelengths designated for red light.Type: GrantFiled: October 2, 2008Date of Patent: March 23, 2010Assignee: Hitachi, Ltd.Inventors: Yuka Utsumi, Katsumi Kondo, Ikuo Hiyama, Osamu Itoh, Masahito Ohe, Kazuhiko Yanagawa, Keiichiro Ashizawa
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Publication number: 20100066943Abstract: The liquid crystal display apparatus includes a liquid crystal panel and the back light device for emitting the light from a light source to the liquid crystal panel through a lens. The light source includes a first LED for emitting the light of a first color, a second LED for emitting the light of a second color, a third LED for emitting the light of a third color, a fourth LED for emitting the light of the third color, a fifth LED for emitting the light of the second color, and a sixth LED for emitting the light of the first color. The first, second, third, fourth, fifth and sixth LEDs are arranged on the wiring board in such a manner as to offset the deviation of the light distribution.Type: ApplicationFiled: August 17, 2009Publication date: March 18, 2010Inventors: Yutaka AKIBA, Ikuo Hiyama, Kiyomi Nakamura, Yoshinori Aono, Makoto Tsumura, Akitoyo Konno, Norihiro Uemura
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Publication number: 20100066949Abstract: Provided is a liquid crystal display apparatus including: a liquid crystal panel including a pair of substrates; a liquid crystal layer sandwiched by the pair of substrates; plural electrodes formed on at least one of the pair of substrates; and a pair of polarizers provided in respective outsides of the pair of substrates; and a back light unit provided in a rear of the liquid crystal panel, in which one of the pair of polarizers, which is provided at a side of the back light unit, includes at least two types of layers which cause polarization, and in which the two types of layers include a first layer provided on a side of the liquid crystal layer and a second layer provided on a side of the back light unit, the first layer being a negative uniaxial polarizer layer, the second layer being a positive uniaxial polarizer layer.Type: ApplicationFiled: August 12, 2009Publication date: March 18, 2010Inventors: Yuka UTSUMI, Ikuo Hiyama, Katsumi Kondo, Shigeru Matsuyama