Patents by Inventor Yuichi Kawahira
Yuichi Kawahira 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: 11988918Abstract: Provided is an optical element including a phase difference layer. The phase difference layer is a laminate of n first phase difference layers and m second phase difference layers. The n first phase difference layers each contain first anisotropic molecules with tilt angles different between a viewing surface side and a back surface side. The m second phase difference layers each contain second anisotropic molecules with tilt angles different between a viewing surface side and a back surface side. Slow axes of the n first phase difference layers are in a same orientation. Slow axes of the m second phase difference layers are in a same orientation. The slow axes of the n first phase difference layers and the slow axes of the m second phase difference layers are anti-parallel to each other and are parallel to or perpendicular to the transmission axis of the first polarizer.Type: GrantFiled: October 20, 2023Date of Patent: May 21, 2024Assignee: Sharp Display Technology CorporationInventors: Yuichi Kawahira, Masahiro Hasegawa, Ryosuke Saigusa, Jianeng Xu, Akira Sakai
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Patent number: 11982896Abstract: Provided is a liquid crystal display device and a polarizing plate capable of improving the contrast ratio in the front direction. The polarizing plate includes a pair of polarizers including a first polarizer and a second polarizer whose transmission axes are parallel to each other; a retarder between the paired polarizers; and a diffusion layer in at least one of a region between the paired polarizers or a region on a side without the retarder of the first polarizer.Type: GrantFiled: February 7, 2023Date of Patent: May 14, 2024Assignee: SHARP KABUSHIKI KAISHAInventors: Akira Sakai, Yuichi Kawahira, Masahiro Hasegawa, Kiyoshi Minoura
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Publication number: 20240103314Abstract: Provided is a display device in which warping of a display panel is sufficiently reduced or prevented. The display device includes: a display panel; and a polarizer, the polarizer being provided with at least one notch that extends inward from an outer edge of the polarizer.Type: ApplicationFiled: August 29, 2023Publication date: March 28, 2024Inventors: Ryosuke SAIGUSA, Akira SAKAI, Yuichi KAWAHIRA, Masahiro HASEGAWA
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Patent number: 11934069Abstract: An optical element includes, sequentially from a viewing surface side toward a back surface side: a viewing-surface-side polarizer; a retarder; and a back-surface-side polarizer, a transmission axis of the viewing-surface-side polarizer and a transmission axis of the back-surface-side polarizer being parallel to each other, the optical element having an average angle ? between an angle ?1 and an angle ?2 of greater than 0° and smaller than 90°, wherein the angle ?1 represents an angle formed by an optical axis of the retarder on a surface close to the back surface with the surface close to the back surface; and the angle ?2 represents an angle formed by an optical axis of the retarder on a surface close to the viewing surface with the surface close to the viewing surface.Type: GrantFiled: August 23, 2022Date of Patent: March 19, 2024Assignee: SHARP DISPLAY TECHNOLOGY CORPORATIONInventors: Akira Sakai, Yuichi Kawahira, Masahiro Hasegawa, Ryosuke Saigusa
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Patent number: 11927850Abstract: Provided is a liquid crystal display device having high luminance and high CR in a front direction and especially useful as a head-mounted liquid crystal display device, for example. The liquid crystal display device includes: a liquid crystal panel; an optical element; and a backlight, arranged in this order from a viewing surface side. The optical element includes a first polarizer, a retardation layer, and a second polarizer. The first polarizer, the retardation layer, and the second polarizer are arranged in this order from the viewing surface side. The first polarizer and the second polarizer are reflection polarizers. A reflection axis of the first polarizer and a reflection axis of the second polarizer are parallel to each other. In oblique directions at azimuths of 0°, 45°, and 90° at a polar angle of 60°, a polarization state of light incident on the first polarizer is elliptical polarization.Type: GrantFiled: May 10, 2023Date of Patent: March 12, 2024Assignee: Sharp Display Technology CorporationInventors: Yuichi Kawahira, Masahiro Hasegawa, Ryosuke Saigusa, Akira Sakai
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Patent number: 11874549Abstract: Provided are an optical element that can achieve both color difference control and luminance reduction at an oblique viewing angle, and a liquid crystal display device including the optical element and having excellent display quality. The optical element includes: a first polarizer; a first phase difference layer; a second phase difference layer; and a second polarizer, the first polarizer, the first phase difference layer, the second phase difference layer, and the second polarizer being arranged in the stated order, the first phase difference layer satisfying the formula nx>ny?nz, the second phase difference layer satisfying the formula nz>nx?ny, the first polarizer and the second polarizer being linear polarizers, transmission axes of the first polarizer and the second polarizer being parallel to each other, a slow axis of the first phase difference layer being orthogonal to a polarization axis of the first polarizer.Type: GrantFiled: May 19, 2023Date of Patent: January 16, 2024Assignee: Sharp Display Technology CorporationInventors: Ryosuke Saigusa, Akira Sakai, Yuichi Kawahira, Masahiro Hasegawa
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Patent number: 11841575Abstract: A liquid crystal display device includes a first polarizing plate, a first substrate including a thin-film transistor, a liquid crystal layer containing liquid crystal molecules, a second substate, a second polarizing plate, and a backlight. The first polarizing plate, the first substate, the liquid crystal layer, the second substrate, the second polarizing plate, and the backlight are arranged in this order. The first substrate has a display area and a frame area placed on an outer edge of the display region. The liquid crystal display device has an ink layer between the frame area of the first substrate and the first polarizing plate. The liquid crystal display device has an internal reflectance ratio y of 0.2 to 0.3. The internal reflectance ratio y is expressed by Formula (1-1).Type: GrantFiled: April 13, 2023Date of Patent: December 12, 2023Assignee: Sharp Display Technology CorporationInventors: Akira Hirai, Yuichi Kawahira, Akira Sakai
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Publication number: 20230384634Abstract: Provided are an optical element that can achieve both color difference control and luminance reduction at an oblique viewing angle, and a liquid crystal display device including the optical element and having excellent display quality. The optical element includes: a first polarizer; a first phase difference layer; a second phase difference layer; and a second polarizer, the first polarizer, the first phase difference layer, the second phase difference layer, and the second polarizer being arranged in the stated order, the first phase difference layer satisfying the formula nx>ny?nz, the second phase difference layer satisfying the formula nz>nx?ny, the first polarizer and the second polarizer being linear polarizers, transmission axes of the first polarizer and the second polarizer being parallel to each other, a slow axis of the first phase difference layer being orthogonal to a polarization axis of the first polarizer.Type: ApplicationFiled: May 19, 2023Publication date: November 30, 2023Inventors: Ryosuke SAIGUSA, Akira SAKAI, Yuichi KAWAHIRA, Masahiro HASEGAWA
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Publication number: 20230375873Abstract: Provided is a liquid crystal display device sequentially including: a first polarizer; a liquid crystal panel; a second polarizer; a biaxial retarder; a third polarizer; and a backlight including a light source and a prism sheet disposed closer to the viewing surface side than the light source is. The prism sheet includes prisms arranged in multiple columns on a surface close to the viewing surface side. The liquid crystal display has a light diffusion property curve having no side lobe or having a side lobe satisfying a ratio of a local maximum luminance to a local minimum luminance of 1.35 or less, the light diffusion property curve being obtained by plotting a luminance in a white display state in a direction perpendicular to ridge lines of the prisms against a polar angle.Type: ApplicationFiled: May 10, 2023Publication date: November 23, 2023Inventors: Yuichi KAWAHIRA, Masahiro HASEGAWA, Ryosuke SAIGUSA, Akira SAKAI
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Patent number: 11822181Abstract: Provided is a liquid crystal display device sequentially including: a first polarizer; a liquid crystal panel; a second polarizer; a biaxial retarder; a third polarizer; and a backlight including a light source and a prism sheet disposed closer to the viewing surface side than the light source is. The prism sheet includes prisms arranged in multiple columns on a surface close to the viewing surface side. The liquid crystal display has a light diffusion property curve having no side lobe or having a side lobe satisfying a ratio of a local maximum luminance to a local minimum luminance of 1.35 or less, the light diffusion property curve being obtained by plotting a luminance in a white display state in a direction perpendicular to ridge lines of the prisms against a polar angle.Type: GrantFiled: May 10, 2023Date of Patent: November 21, 2023Assignee: Sharp Display Technology CorporationInventors: Yuichi Kawahira, Masahiro Hasegawa, Ryosuke Saigusa, Akira Sakai
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Publication number: 20230367156Abstract: Provided is a liquid crystal display device having high luminance and high CR in a front direction and especially useful as a head-mounted liquid crystal display device, for example. The liquid crystal display device includes: a liquid crystal panel; an optical element; and a backlight, arranged in this order from a viewing surface side. The optical element includes a first polarizer, a retardation layer, and a second polarizer. The first polarizer, the retardation layer, and the second polarizer are arranged in this order from the viewing surface side. The first polarizer and the second polarizer are reflection polarizers. A reflection axis of the first polarizer and a reflection axis of the second polarizer are parallel to each other. In oblique directions at azimuths of 0°, 45°, and 90° at a polar angle of 60°, a polarization state of light incident on the first polarizer is elliptical polarization.Type: ApplicationFiled: May 10, 2023Publication date: November 16, 2023Inventors: Yuichi KAWAHIRA, Masahiro HASEGAWA, Ryosuke SAIGUSA, Akira SAKAI
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Publication number: 20230333427Abstract: A liquid crystal display device includes a first polarizing plate, a first substrate including a thin-film transistor, a liquid crystal layer containing liquid crystal molecules, a second substrate, a second polarizing plate, and a backlight. The first polarizing plate, the first substrate, the liquid crystal layer, the second substrate, the second polarizing plate, and the backlight are arranged in this order. The first substrate has a display area and a frame area placed on an outer edge of the display region. The liquid crystal display device has an ink layer between the frame area of the first substrate and the first polarizing plate. The liquid crystal display device has an internal reflectance ratio y of 0.2 to 0.3. The internal reflectance ratio y is expressed by Formula (1-1).Type: ApplicationFiled: April 13, 2023Publication date: October 19, 2023Inventors: Akira HIRAI, Yuichi KAWAHIRA, Akira SAKAI
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Publication number: 20230314868Abstract: Provided is a liquid crystal display device in which reflection and light leakage from oblique directions are reduced or prevented. The liquid crystal display device includes, sequentially in the following order from a back surface side: a first polarizer; a liquid crystal panel; a second polarizer; a first retardation layer; and a third polarizer, wherein light transmitted in an oblique direction between the second polarizer and the third polarizer is elliptically polarized light.Type: ApplicationFiled: March 28, 2023Publication date: October 5, 2023Inventors: Akira SAKAI, Ryosuke SAIGUSA, Yuichi KAWAHIRA, Masahiro HASEGAWA, Kiyoshi MINOURA
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Patent number: 11774813Abstract: Provided are a liquid crystal display device that can increase light use efficiency and reduce external light reflection, and a method of producing the liquid crystal display device. The liquid crystal display device sequentially includes, from a back surface side toward a viewing surface side: a first substrate; a liquid crystal layer; and a second substrate, the liquid crystal display device including sub-pixels each including an optical opening allowing light to pass through, the first substrate sequentially including, from the back surface side toward the viewing surface side: a supporting substrate; a metal layer surrounding the optical openings; and a resist layer being superimposed with the metal layer and being in contact with the metal layer, an end of the resist layer being superimposed with an end of the metal layer and having a taper angle ? of 40° or more.Type: GrantFiled: December 9, 2022Date of Patent: October 3, 2023Assignee: Sharp Display Technology CorporationInventors: Yuichi Kawahira, Akira Hirai, Akira Sakai
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Publication number: 20230185139Abstract: Provided are a liquid crystal display device that can increase light use efficiency and reduce external light reflection, and a method of producing the liquid crystal display device. The liquid crystal display device sequentially includes, from a back surface side toward a viewing surface side: a first substrate; a liquid crystal layer; and a second substrate, the liquid crystal display device including sub-pixels each including an optical opening allowing light to pass through, the first substrate sequentially including, from the back surface side toward the viewing surface side: a supporting substrate; a metal layer surrounding the optical openings; and a resist layer being superimposed with the metal layer and being in contact with the metal layer, an end of the resist layer being superimposed with an end of the metal layer and having a taper angle ? of 40° or more.Type: ApplicationFiled: December 9, 2022Publication date: June 15, 2023Inventors: Yuichi KAWAHIRA, Akira HIRAI, Akira SAKAI
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Publication number: 20230185123Abstract: Provided is a liquid crystal display device and a polarizing plate capable of improving the contrast ratio in the front direction. The polarizing plate includes a pair of polarizers including a first polarizer and a second polarizer whose transmission axes are parallel to each other; a retarder between the paired polarizers; and a diffusion layer in at least one of a region between the paired polarizers or a region on a side without the retarder of the first polarizer.Type: ApplicationFiled: February 7, 2023Publication date: June 15, 2023Inventors: AKIRA SAKAI, YUICHI KAWAHIRA, MASAHIRO HASEGAWA, KIYOSHI MINOURA
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Patent number: 11675233Abstract: The present, invention provides a liquid crystal display device that can exhibit excellent retardation stability against heat and that can prevent reduction in contrast ratio due to scattering even when the liquid crystal display device includes a retardation layer formed by polymerization of a reactive monomer, and a method for producing a liquid crystal display device suitable for production of the liquid crystal display device. The liquid crystal display device of the present invention includes paired substrates and a liquid crystal layer provided between the paired substrates. At least one of the paired substrates includes a retardation layer formed from a polymer of at least one type of monomer. The at least one type of monomer includes a photo-aligning monomer that is to be aligned by polarized light.Type: GrantFiled: March 22, 2018Date of Patent: June 13, 2023Assignee: SHARP KABUSHIKI KAISHAInventors: Masanobu Mizusaki, Yuichi Kawahira
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Patent number: 11668966Abstract: The liquid crystal display device includes: a display region for displaying an image; and a frame region surrounding the display region, the liquid crystal display device sequentially including from a viewing surface side toward a back surface side: a first polarizing plate; a first substrate provided with a switching element connected to a gate line and a source line; a liquid crystal layer; a second substrate; and a second polarizing plate, in the frame region, the first substrate sequentially including from a viewing surface side toward a back surface side a support substrate, a reflectance-reducing layer, and a metal line layer that overlaps the reflectance-reducing layer and includes at least one of a gate line layer provided with the gate line or a source line layer provided with the source line, the reflectance-reducing layer having a lower viewing surface side reflectance than the metal line layer.Type: GrantFiled: May 18, 2022Date of Patent: June 6, 2023Assignee: SHARP KABUSHIKI KAISHAInventors: Akira Hirai, Yuichi Kawahira, Akira Sakai
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Publication number: 20230095922Abstract: Provided are a polarizing plate including a polarizing layer containing a lyotropic liquid crystal compound and capable of achieving uniform polarization properties over a large area, and a display device equipped with the polarizing plate. The polarizing plate includes: an alignment film; and a polarizing layer on the alignment film. The alignment film contains an alignment film polymer, has a static contact angle with water of 60° or smaller, and has a slow axis. The polarizing layer contains a lyotropic liquid crystal compound and has an absorption axis parallel to the above slow axis. The lyotropic liquid crystal compound is preferably dichroic.Type: ApplicationFiled: September 8, 2022Publication date: March 30, 2023Inventors: Miho YAMADA, Akira SAKAI, Masahiro HASEGAWA, Yuichi KAWAHIRA, Hiroaki ASAGI
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Patent number: 11604379Abstract: Provided is a liquid crystal display device and a polarizing plate capable of improving the contrast ratio in the front direction. The polarizing plate includes a pair of polarizers including a first polarizer and a second polarizer whose transmission axes are parallel to each other; a retarder between the paired polarizers; and a diffusion layer in at least one of a region between the paired polarizers or a region on a side without the retarder of the first polarizer.Type: GrantFiled: May 27, 2021Date of Patent: March 14, 2023Assignee: SHARP KABUSHIKI KAISHAInventors: Akira Sakai, Yuichi Kawahira, Masahiro Hasegawa, Kiyoshi Minoura