Patents by Inventor Yoshitaka Itoh

Yoshitaka Itoh 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).

  • Patent number: 7026901
    Abstract: A cold head is disposed in an insulating container and cooled by a refrigerator. A superconductor is disposed in the insulating container, contacting the cold head, and is cooled to its superconduction transition temperature or lower by heat conduction. A magnetizing coil is disposed outside the insulating container for applying a magnetic field to the superconductor. Control is performed so that a magnetic field determined considering the magnetic field to be captured by the superconductor is applied. A pulsed magnetic field is applied to the superconductor a plurality of times. Each pulsed magnetic field is applied when the temperature of the superconductor is a predetermined temperature or lower. A maximum pulsed magnetic field is applied at least once in an initial or intermediate stage of the repeated application of pulsed magnetic fields. After that, a pulsed magnetic field equal to or less than the maximum pulsed magnetic field is applied.
    Type: Grant
    Filed: February 6, 2002
    Date of Patent: April 11, 2006
    Assignee: Aisin Seiki Kabushiki Kaisha
    Inventors: Yousuke Yanagi, Tetsuo Oka, Yoshitaka Itoh, Masaaki Yoshikawa
  • Publication number: 20050271312
    Abstract: A projection-type display device 100 including a light source 10, a luminance modulation light valve having a plurality of pixels capable of independently controlling a transmission factor T1, dichroic mirrors 44a and 44b that divided the light from the luminance modulation light valve into the three primary colors of red, green and blue, a plurality of color modulation light valves into which light divided with dichroic mirrors 44a and 44b respectively enters and have a plurality of pixels capable of independently controlling a transmission factor T2, and a dichroic prism 48 that synthesizes light from each of the color modulation light valves, and is provided with a relay optical system 16 on the light path of a luminance modulation section 14 and a color modulation section 18 that forms an optical image of the luminance modulation light valve on the pixel surfaces of each of the color modulation light valves.
    Type: Application
    Filed: December 20, 2004
    Publication date: December 8, 2005
    Applicant: Seiko Epson Corporation
    Inventors: Shoichi Uchiyama, Yoshitaka Itoh, Junichi Nakamura, Takashi Nitta, Tsunemori Asahi
  • Publication number: 20050259308
    Abstract: A projector capable of displaying a moving picture image in good quality with a clear outline and few blurs includes a light source, a pseudo rectangular light bundle generating device to generate a band-shaped illumination light bundle from a light bundle emitted from the light source, and an optically scanning device to scan with the illumination light bundle emitted from the pseudo rectangular light bundle generating device on an optically modulating apparatus. The projector further includes an illumination light bundle shaping device to shape the illumination light bundle into a desired shape of illumination light bundle, the illumination light bundle shaping device being in an optical path of the illumination light bundle emitted from the pseudo rectangular light bundle generating device.
    Type: Application
    Filed: May 18, 2005
    Publication date: November 24, 2005
    Applicant: SEIKO EPSON CORPORATION
    Inventors: Yoshitaka Itoh, Hideki Kojima
  • Publication number: 20050248736
    Abstract: A projector which is small in size and excellent in light utilization efficiency while keeping the advantage of a spatially-pixel-arrangement type is provided. The luminous flux emitted from a light source is separated by a color separation system into a plurality of kinds of colors of light different in exit direction. These separated colors of light are modulated by a light valve, to form first optical images. The light valve has a plurality of sub-pixels provided corresponding to the colors of light and micro-lenses to focus the colors of light corresponding to the sub-pixels. The sub-pixels are structured in a size nearly equal to a size of a color of light to be focused on the relevant sub-pixel by micro-lenses. Accordingly, the first optical image is in a form non-analogous with the actual projection image. The first optical images are converted into second optical images having a desired aspect ratio by an anamophic projection system, and then projected.
    Type: Application
    Filed: May 6, 2005
    Publication date: November 10, 2005
    Applicant: Seiko Epson Corporation
    Inventor: Yoshitaka Itoh
  • Publication number: 20050174495
    Abstract: A projection-type display device 1 including a light source 10, an optical integrator 20, dichroic mirrors 30 and 35, a reflecting mirror 36, a relay optical system 40, parallelizing lenses 50B, 50G and 50R, liquid crystal light valves 60B, 60G and 60R, incident side lenses 70B, 70G and 70R, a light-synthesizing cross dichroic prism 80, a relay lens 90, an emergent side lens 95, a liquid crystal light valve 100 and a projection lens 110, and liquid crystal light valve 100 is provided in the rear stage of liquid crystal light valves 60B, 60G and 60R.
    Type: Application
    Filed: December 17, 2004
    Publication date: August 11, 2005
    Applicant: SEIKO EPSON CORPORATION
    Inventors: Yoshitaka Itoh, Shohei Yoshida, Shoichi Uchiyama, Junichi Nakamura, Takashi Nitta, Tsunemori Asahi
  • Publication number: 20050169572
    Abstract: Aspects of the invention can provide an illumination device capable of preventing or reducing a reduction in efficiency of utilization of lights emitted from the light source, and also suitable to display high-quality moving images, and a display device and a projection type display device using this illumination device.
    Type: Application
    Filed: January 26, 2005
    Publication date: August 4, 2005
    Applicant: SEIKO EPSON CORPORATION
    Inventor: Yoshitaka Itoh
  • Publication number: 20050083573
    Abstract: A polarization luminaire is disclosed having a light source, a system of the optical integrator, a polarized light splitting device for splitting a light emitted from the light source into two kinds of polarized lights whose polarization directions are perpendicular to each other and whose traveling directions are apart from each other by an angle of less than 90 degrees, and a polarization conversion device for causing the two kinds of polarized lights to have the same polarization direction. The polarized light splitting device is placed on one of the entrance side and the outputting side of the first lens plate of the system of the optical integrator or is placed within the second lens plate. A prism beam splitter having a polarized light splitting film constituted by a thermally stable dielectric multi-layer film is suitable for the polarized light splitting device. Most of the polarized lights can be utilized by causing the polarized lights to have the same polarization direction.
    Type: Application
    Filed: September 1, 2004
    Publication date: April 21, 2005
    Applicant: Seiko Epson Corporation
    Inventors: Yoshitaka Itoh, Kunio Yoneno
  • Patent number: 6778228
    Abstract: A projection-type display apparatus of the invention aiming at solving the problem of heat generation caused by absorption of light by a polarizing means of a liquid crystal light valve. To overcome this problem, the projection-type display apparatus of the invention includes a light source, a light valve for modulating the light from the light source, and a projection optical means for projecting the light modulated by the light valve, with the light valve including a liquid crystal panel and a polarizing means, provided on the light source side of the liquid crystal panel, and the polarizing means being formed of a multi-layered film which primarily transmits one of two types of polarization axis component light beams and primarily reflects the other of the two types of polarization axis component light beams.
    Type: Grant
    Filed: August 14, 2002
    Date of Patent: August 17, 2004
    Assignee: Seiko Epson Corporation
    Inventors: Osamu Murakami, Akitaka Yajima, Yoshitaka Itoh
  • Publication number: 20040141153
    Abstract: A projector 1 is mainly composed of a polarized light beam illumination device, a collimating lens 170a, polarized beam splitter, a reflection-type liquid crystal device, and a projection optical system. The polarized light beam illumination device includes a light source, a first optical element, and a second optical element. Light emitted from the light source is divided into a plurality of intermediate light beams by the first optical element, and then converted into polarized light beams having substantially one polarization direction by the second optical element. The polarized light beams enter the collimating lens, are transmitted by the polarized beam splitter, modulated by the reflection-type liquid crystal device, reflected by the polarized beam splitter, and then projected on a projection plane via the projection optical system.
    Type: Application
    Filed: January 2, 2004
    Publication date: July 22, 2004
    Applicant: Seiko Epson Corporation
    Inventor: Yoshitaka Itoh
  • Patent number: 6746123
    Abstract: A projector 1 is mainly composed of a polarized light beam illumination device, a collimating lens 170a, polarized beam splitter, a reflection-type liquid crystal device, and a projection optical system. The polarized light beam illumination device includes a light source, a first optical element, and a second optical element. Light emitted from the light source is divided into a plurality of intermediate light beams by the first optical element, and then converted into polarized light beams having substantially one polarization direction by the second optical element. The polarized light beams enter the collimating lens, are transmitted by the polarized beam splitter, modulated by the reflection-type liquid crystal device, reflected by the polarized beam splitter, and then projected on a projection plane via the projection optical system.
    Type: Grant
    Filed: December 4, 2002
    Date of Patent: June 8, 2004
    Assignee: Seiko Epson Corporation
    Inventor: Yoshitaka Itoh
  • Patent number: 6667834
    Abstract: A polarization luminaire is disclosed having a light source, a system of the optical integrator, a polarized light splitting device for splitting a light emitted from the light source into two kinds of polarized lights whose polarization directions are perpendicular to each other and whose traveling directions are apart from each other by an angle of less than 90 degrees, and a polarization conversion device for causing the two kinds of polarized lights to have the same polarization direction. The polarized light splitting device is placed on one of the entrance side and the outputting side of the first lens plate of the system of the optical integrator or is placed within the second lens plate. A prism beam splitter having a polarized light splitting film constituted by a thermally stable dielectric multi-layer film is suitable for the polarized light splitting device. Most of the polarized lights can be utilized by causing the polarized lights to have the same polarization direction.
    Type: Grant
    Filed: April 19, 2002
    Date of Patent: December 23, 2003
    Assignee: Seiko Epson Corporation
    Inventor: Yoshitaka Itoh
  • Publication number: 20030095236
    Abstract: A projector 1 is mainly composed of a polarized light beam illumination device, a collimating lens 170a, polarized beam splitter, a reflection-type liquid crystal device, and a projection optical system. The polarized light beam illumination device includes a light source, a first optical element, and a second optical element. Light emitted from the light source is divided into a plurality of intermediate light beams by the first optical element, and then converted into polarized light beams having substantially one polarization direction by the second optical element. The polarized light beams enter the collimating lens, are transmitted by the polarized beam splitter, modulated by the reflection-type liquid crystal device, reflected by the polarized beam splitter, and then projected on a projection plane via the projection optical system.
    Type: Application
    Filed: December 4, 2002
    Publication date: May 22, 2003
    Applicant: Seiko Epson Corporation
    Inventor: Yoshitaka Itoh
  • Patent number: 6529250
    Abstract: A projection-type display apparatus of the invention aiming at solving the problem of heat generation caused by absorption of light by a polarizing means of a liquid crystal light valve. To overcome this problem, the projection-type display apparatus of the invention includes a light source, a light valve for modulating the light from the light source, and a projection optical means for projecting the light modulated by the light valve, with the light valve including a liquid crystal panel and a polarizing means, provided on the light source side of the liquid crystal panel, and the polarizing means being formed of a multi-layered film which primarily transmits one of two types of polarization axis component light beams and primarily reflects the other of the two types of polarization axis component light beams.
    Type: Grant
    Filed: May 21, 1998
    Date of Patent: March 4, 2003
    Assignee: Seiko Epson Corporation
    Inventors: Osamu Murakami, Akitaka Yajima, Yoshitaka Itoh
  • Publication number: 20030025845
    Abstract: A projection-type display apparatus of the invention aiming at solving the problem of heat generation caused by absorption of light by a polarizing means of a liquid crystal light valve. To overcome this problem, the projection-type display apparatus of the invention includes a light source, a light valve for modulating the light from the light source, and a projection optical means for projecting the light modulated by the light valve, with the light valve including a liquid crystal panel and a polarizing means, provided on the light source side of the liquid crystal panel, and the polarizing means being formed of a multi-layered film which primarily transmits one of two types of polarization axis component light beams and primarily reflects the other of the two types of polarization axis component light beams.
    Type: Application
    Filed: August 14, 2002
    Publication date: February 6, 2003
    Applicant: Seiko Epson Corporation
    Inventors: Osamu Murakami, Akitaka Yajima, Yoshitaka Itoh
  • Patent number: 6513953
    Abstract: An illumination system includes a light source that emits unpolarized light, a power variation optical relay system that changes the size of a light beam emitted by the light source, a superposition optical system that effects illumination of an illumination region by an incident light beam, a polarization conversion system that is provided at a selected position along a light path from the incident surface of the power variation optical relay system to the exit surface of the superposition optical system to convert an incident beam of unpolarized light to a light beam having linearly polarized components with one type of polarization direction and emits the converted light beam. The size of a light beam entering the polarization conversion system in a prescribed direction is reduced by the power variation optical relay system.
    Type: Grant
    Filed: February 22, 2000
    Date of Patent: February 4, 2003
    Assignee: Seiko Epson Corporation
    Inventor: Yoshitaka Itoh
  • Patent number: 6497485
    Abstract: A projector is mainly composed of a polarized light beam illumination device, a collimating lens, polarized beam splitter, a reflection-type liquid crystal device, and a projection optical system. The polarized light beam illumination device includes a light source, a first optical element, and a second optical element. Light emitted from the light source is divided into a plurality of intermediate light beams by the first optical element, and then converted into polarized light beams having substantially one polarization direction by the second optical element. The polarized light beams enter the collimating lens, are transmitted by the polarized beam splitter, modulated by the reflection-type liquid crystal device, reflected by the polarized beam splitter, and then projected on a projection plane via the projection optical system.
    Type: Grant
    Filed: January 20, 2000
    Date of Patent: December 24, 2002
    Assignee: Seiko Epson Corporation
    Inventor: Yoshitaka Itoh
  • Patent number: 6471358
    Abstract: The present invention provides a lighting device that has two lamp units and is suitable for a light source of a projector-type display apparatus to realize bright illumination, and also a projector-type display apparatus with such a lighting device incorporated therein. The lighting device includes a light source unit and an integrator optical system and enables an illumination area to be illuminated uniformly and evenly with the light emitted from the light source unit and transmitted via the integrator optical system. The light source unit includes a pair of lamp units arranged in parallel, and a reflector of each lamp unit has a contour with both sides cut off. The pair of lamp units are preferably arrayed in a direction perpendicular to a longitudinal direction of the illumination area. This structure realizes a small-sized, compact lighting device with a high quantity of output light.
    Type: Grant
    Filed: April 25, 2000
    Date of Patent: October 29, 2002
    Assignee: Seiko Epson Corporation
    Inventors: Yoshitaka Itoh, Toshiaki Hashizume
  • Publication number: 20020141058
    Abstract: A polarization luminaire is disclosed having a light source, a system of the optical integrator, a polarized light splitting device for splitting a light emitted from the light source into two kinds of polarized lights whose polarization directions are perpendicular to each other and whose traveling directions are apart from each other by an angle of less than 90 degrees, and a polarization conversion device for causing the two kinds of polarized lights to have the same polarization direction. The polarized light splitting device is placed on one of the entrance side and the outputting side of the first lens plate of the system of the optical integrator or is placed within the second lens plate. A prism beam splitter having a polarized light splitting film constituted by a thermally stable dielectric multi-layer film is suitable for the polarized light splitting device. Most of the polarized lights can be utilized by causing the polarized lights to have the same polarization direction.
    Type: Application
    Filed: April 19, 2002
    Publication date: October 3, 2002
    Applicant: Seiko Epson Corporation
    Inventor: Yoshitaka Itoh
  • Patent number: 6445500
    Abstract: A polarization luminaire is disclosed having a light source, a system of the optical integrator, a polarized light splitting device for splitting a light emitted from the light source into two kinds of polarized lights whose polarization directions are perpendicular to each other and whose traveling directions are apart from each other by an angle of less than 90 degrees, and a polarization conversion device for causing the two kinds of polarized lights to have the same polarization direction. The polarized light splitting device is placed on one of the entrance side and the outputting side of the first lens plate of the system of the optical integrator or is placed within the second lens plate. A prism beam splitter having a polarized light splitting film constituted by a thermally stable dielectric multi-layer film is suitable for the polarized light splitting device. Most of the polarized lights can be utilized by causing the polarized lights to have the same polarization direction.
    Type: Grant
    Filed: October 18, 2000
    Date of Patent: September 3, 2002
    Assignee: Seiko Epson Corporation
    Inventor: Yoshitaka Itoh
  • Patent number: RE38225
    Abstract: An apparatus which makes dark lines due to a central axis of a cross dichroic prism sufficiently inconspicuous. In a second lens array, minute lenses arranged on the same column include three different types of minute lenses having optical axes at different positions. Each row of the minute lenses consists of one of the three types of minute lenses. Partial light fluxes respectively passing through the minute lenses have optical axes at different positions relative to a center of a lighting area of a liquid-crystal light bulb, so as to illuminate different illumination areas.
    Type: Grant
    Filed: October 24, 2001
    Date of Patent: August 19, 2003
    Assignee: Seiko Epson Corporation
    Inventors: Yoshitaka Itoh, Toshiaki Hashizume