Patents by Inventor Taro Imahase

Taro Imahase 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: 7929064
    Abstract: A projection-type video display apparatus has a polarizing beam splitter for matching light, which is outputted by a light source unit, to one of S polarizing light and P polarizing light, an optical characteristics switching element for electrically and periodically switching a wavelength band of light outputted by the polarizing beam splitter, a video display element, as a light valve element, for forming an optical image from light outputted by the light source unit, in accordance with a video signal, and a radiating unit for radiating a plurality of color light, which are sequentially outputted by the optical characteristics switching element, to the video display element, wherein light outputted by the video display element is incident on a projecting lens, and a light path from the light source unit to the projecting lens is U-shaped. Consequently, the projection-type video display apparatus becomes compact and has improved contrast.
    Type: Grant
    Filed: July 11, 2008
    Date of Patent: April 19, 2011
    Assignee: Hitachi, Ltd.
    Inventors: Satoshi Ouchi, Taro Imahase, Nobuaki Kabuto
  • Patent number: 7553024
    Abstract: An image display device includes a light source which outputs a first light including a first color light, a second color light and a third color light, a polarity converter which unifies polarities of the first light into a single polarity, a dichroic mirror which separates the first color light from the first light which is output by the polarity converter, and first to third reflective liquid crystal display elements, respectively, installed for the first to third color lights. First to third polarized beam splitters are provided together with first and second wavelength selective polarity rotator elements. A projection lens is provided so as to project a light combined by the third polarized beam splitter, and the first color light, which is reflected by the first reflective liquid crystal display element, permeates the first polarized beam splitter and the third polarized beam splitter.
    Type: Grant
    Filed: April 12, 2006
    Date of Patent: June 30, 2009
    Assignee: Hitachi, Ltd.
    Inventors: Satoshi Ouchi, Taro Imahase, Tomohiro Miyoshi, Fukuyasu Abe
  • Patent number: 7474360
    Abstract: A projection-type video display apparatus has a polarizing beam splitter for matching light, which is outputted by a light source unit, to one of S polarizing light and P polarizing light, an optical characteristics switching element for electrically and periodically switching a wavelength band of light outputted by the polarizing beam splitter, a video display element, as a light valve element, for forming an optical image from light outputted by the light source unit, in accordance with a video signal, and a radiating unit for radiating a plurality of color light, which are sequentially outputted by the optical characteristics switching element, to the video display element, wherein light outputted by the video display element is incident on a projecting lens, and a light path from the light source unit to the projecting lens is U-shaped. Consequently, the projection-type video display apparatus becomes compact and has improved contrast.
    Type: Grant
    Filed: September 12, 2005
    Date of Patent: January 6, 2009
    Assignee: Hitachi, Ltd.
    Inventors: Satoshi Ouchi, Taro Imahase, Nobuaki Kabuto
  • Publication number: 20080278636
    Abstract: A projection-type video display apparatus has a polarizing beam splitter for matching light, which is outputted by a light source unit, to one of S polarizing light and P polarizing light, an optical characteristics switching element for electrically and periodically switching a wavelength band of light outputted by the polarizing beam splitter, a video display element, as a light valve element, for forming an optical image from light outputted by the light source unit, in accordance with a video signal, and a radiating unit for radiating a plurality of color light, which are sequentially outputted by the optical characteristics switching element, to the video display element, wherein light outputted by the video display element is incident on a projecting lens, and a light path from the light source unit to the projecting lens is U-shaped. Consequently, the projection-type video display apparatus becomes compact and has improved contrast.
    Type: Application
    Filed: July 11, 2008
    Publication date: November 13, 2008
    Applicant: HITACHI, LTD.
    Inventors: Satoshi Ouchi, Taro Imahase, Nobuaki Kabuto
  • Patent number: 7352416
    Abstract: A liquid crystal display element comprising two transparent substrates, at least one of which is transparent, and a liquid crystal layer interposed between the two substrates. A plurality of pixels and active elements for driving the liquid crystal at the plurality of pixels are incorporated into at least one of the two substrates, and an optical axis of an incident light beam upon the liquid crystal layer is present in a plane which is substantially perpendicular to a direction of orientation of liquid crystal molecules on at least one of the two substrates, and the incident light impinges upon the liquid crystal layer in a direction which is inclined by a predetermined angle to the direction of the normal line of the substrate. With this arrangement, a desired phase modulation is obtained through slight motion of the liquid crystal molecules, thereby greatly reducing the liquid crystal drive voltage.
    Type: Grant
    Filed: February 26, 2002
    Date of Patent: April 1, 2008
    Assignee: Hitachi, Ltd.
    Inventors: Shoichi Hirota, Makoto Tsumura, Iwao Takemoto, Hideki Nakagawa, Satoshi Ouchi, Taro Imahase
  • Patent number: 7327520
    Abstract: The present invention discloses the structure of the array lens that at least any one of the diagonal size, vertical size and lateral size of lens cell is set to almost 1/(4.5 or more) for each corresponding size of the display elements, the structure that the diagonal size of lens cell is set to almost 0.18 inch or less, the structure that the total number of lens cells is set to almost 240 or more and the structure that the lens focal distance of lens cell is set to almost 30 mm or less.
    Type: Grant
    Filed: July 25, 2006
    Date of Patent: February 5, 2008
    Assignee: Hitachi, Ltd.
    Inventors: Satoshi Ohuchi, Masahiko Yatsu, Taro Imahase, Tomohiro Miyoshi, Yasuo Otsuka, Takesuke Maruyama
  • Patent number: 7246907
    Abstract: A compact, light projection type image display apparatus based on reflection image display devices which provide high brightness without contrast deterioration caused by light leakage associated with black image display. The apparatus uses, as polarizers/analyzers for reflection image display devices, reflection polarizing plates which function as polarizing plates by their grating function only in a specific direction. In each light path, the reflection polarizing plate is located just before/after the reflection image display device.
    Type: Grant
    Filed: July 21, 2006
    Date of Patent: July 24, 2007
    Assignee: Hitachi, Ltd.
    Inventors: Taro Imahase, Satoshi Ouchi, Tsutomu Nakashima
  • Patent number: 7170567
    Abstract: A projection type image display apparatus includes a light source to emit light; a polarizing beam splitter to polarize the light received from the light source; a first lens array including a plurality of first lens cells having rectangular shapes to receive the light from the polarizing beam splitter, each first lens cell having a first side and a second side, the first side being longer than the second side, the first lens array having a rectangular shape, the first lens array having a third side and a fourth side, the third side being longer than the fourth side, the first sides of the first lens cells and the third side of the first lens array extending along a first direction; a second lens array including a plurality of second lens cells and being configured to receive the light from the first lens array, the second lens array having a rectangular shape and having a fifth side and a sixth side, the fifth and sixth sides of the second lens array having substantially the same dimensions as the third and
    Type: Grant
    Filed: March 3, 2003
    Date of Patent: January 30, 2007
    Assignee: Hitachi, Ltd.
    Inventors: Satoshi Ouchi, Tomohiro Miyoshi, Taro Imahase, Masahiko Yatsu, Koji Hirata
  • Publication number: 20060256290
    Abstract: A compact, light projection type image display apparatus based on reflection image display devices which provide high brightness without contrast deterioration caused by light leakage associated with black image display. The apparatus uses, as polarizers/analyzers for reflection image display devices, reflection polarizing plates which function as polarizing plates by their grating function only in a specific direction. In each light path, the reflection polarizing plate is located just before/after the reflection image display device.
    Type: Application
    Filed: July 21, 2006
    Publication date: November 16, 2006
    Applicant: HITACHI, LTD.
    Inventors: Taro Imahase, Satoshi Ouchi, Tsutomu Nakashima
  • Publication number: 20060256443
    Abstract: The present invention discloses the structure of the array lens that at least any one of the diagonal size, vertical size and lateral size of lens cell is set to almost 1/(4.5 or more) for each corresponding size of the display elements, the structure that the diagonal size of lens cell is set to almost 0.18 inch or less, the structure that the total number of lens cells is set to almost 240 or more and the structure that the lens focal distance of lens cell is set to almost 30 mm or less.
    Type: Application
    Filed: July 25, 2006
    Publication date: November 16, 2006
    Inventors: Satoshi Ohuchi, Masahiko Yatsu, Taro Imahase, Tomohiro Miyoshi, Yasuo Otsuka, Takesuke Maruyama
  • Patent number: 7106518
    Abstract: The present invention discloses the structure of the array lens that at least any one of the diagonal size, vertical size and lateral size of lens cell is set to almost 1/(4.5 or more) for each corresponding size of the display elements, the structure that the diagonal size of lens cell is set to almost 0.18 inch or less, the structure that the total number of lens cells is set to almost 240 or more and the structure that the lens focal distance of lens cell is set to almost 30 mm or less.
    Type: Grant
    Filed: September 23, 2005
    Date of Patent: September 12, 2006
    Assignee: Hiatchi, Ltd.
    Inventors: Satoshi Ohuchi, Masahiko Yatsu, Taro Imahase, Tomohiro Miyoshi, Yasuo Otsuka, Takesuke Maruyama
  • Publication number: 20060187416
    Abstract: An image display device includes a light source which outputs a first light including a first color light, a second color light and a third color light, a polarity converter which unifies polarities of the first light into a single polarity, a dichroic mirror which separates the first color light from the first light which is output by the polarity converter, and first to third reflective liquid crystal display elements, respectively, installed for the first to third color lights. First to third polarized beam splitters are provided together with first and second wavelength selective polarity rotator elements. A projection lens is provided so as to project a light combined by the third polarized beam splitter, and the first color light, which is reflected by the first reflective liquid crystal display element, permeates the first polarized beam splitter and the third polarized beam splitter.
    Type: Application
    Filed: April 12, 2006
    Publication date: August 24, 2006
    Inventors: Satoshi Ouchi, Taro Imahase, Tomohiro Miyoshi, Fukuyasu Abe
  • Patent number: 7090351
    Abstract: A compact, light projection type image display apparatus based on reflection image display devices which provide high brightness without contrast deterioration caused by light leakage associated with black image display. The apparatus uses, as polarizers/analyzers for reflection image display devices, reflection polarizing plates which function as polarizing plates by their grating function only in a specific direction. In each light path, the reflection polarizing plate is located just before/after the reflection image display device.
    Type: Grant
    Filed: April 11, 2005
    Date of Patent: August 15, 2006
    Assignee: Hitachi, Ltd.
    Inventors: Taro Imahase, Satoshi Ouchi, Tsutomu Nakashima
  • Publication number: 20060139954
    Abstract: In a drive circuit of light emission device arrays each having at least one light emission device, at least one of the light emission diode arrays is pulse-driven with a pulse of phase different from the other light emission device arrays. While the at least one light emission device array driven with a different phase is OFF, a processing circuit acquires the luminiferous level of each of the other light emission device arrays by using the at least one light emission device array which is OFF as a light reception device. Furthermore, a control circuit controls the drive level of the drive circuit for the light emission device arrays which are ON.
    Type: Application
    Filed: August 24, 2005
    Publication date: June 29, 2006
    Inventors: Tomoki Kobori, Satoshi Ouchi, Taro Imahase, Atsushi Maruyama
  • Patent number: 7066600
    Abstract: Disclosed is a compact, light, inexpensive reflection type liquid crystal projector optical unit or reflection type liquid crystal projector which provides high brightness without contrast deterioration caused by light leakage associated with black image display. The unit or projector uses, as a polarizer/analyzer for a reflection liquid crystal panel, a reflection polarizing plate which functions as a polarizing plate by its grating function only in a specific direction. It also uses an auxiliary polarizer and an absorption auxiliary analyzer. Their reflection axis or absorption axis is adjusted according to the characteristic of the reflection liquid crystal panel so as to minimize light leakage associated with black image display.
    Type: Grant
    Filed: June 13, 2005
    Date of Patent: June 27, 2006
    Assignee: Hitachi, Ltd.
    Inventors: Tsutomu Nakashima, Satoshi Ouchi, Taro Imahase, Tomohiro Miyoshi
  • Patent number: 7044607
    Abstract: An image display device has three reflective image display elements for red, green and blue to form an optical image according to a video signal from light output from a light source, and an optical system to supply light onto the display elements and to combine and output the light reflected from the display elements. The image display device includes a first polarity converting unit to convert luminous flux from the light source to S polarized light, a first polarized beam splitter, and second polarized beam splitter. The reflective image display element for green is provided in a vicinity of the first polarized beam splitter, and the light reflected by the first polarized beam splitter and input to the reflective image display element for green is S polarized light. The light output from the reflective image display element for green permeates the first and second polarized beam splitters.
    Type: Grant
    Filed: July 7, 2005
    Date of Patent: May 16, 2006
    Assignee: Hitachi, Ltd.
    Inventors: Satoshi Ouchi, Taro Imahase, Tomohiro Miyoshi, Fukuyasu Abe
  • Publication number: 20060012722
    Abstract: A projection-type video display apparatus has a polarizing beam splitter for matching light, which is outputted by a light source unit, to one of S polarizing light and P polarizing light, an optical characteristics switching element for electrically and periodically switching a wavelength band of light outputted by the polarizing beam splitter, a video display element, as a light valve element, for forming an optical image from light outputted by the light source unit, in accordance with a video signal, and a radiating unit for radiating a plurality of color light, which are sequentially outputted by the optical characteristics switching element, to the video display element, wherein light outputted by the video display element is incident on a projecting lens, and a light path from the light source unit to the projecting lens is U-shaped. Consequently, the projection-type video display apparatus becomes compact and has improved contrast.
    Type: Application
    Filed: September 12, 2005
    Publication date: January 19, 2006
    Applicant: HITACHI, LTD.
    Inventors: Satoshi Ouchi, Taro Imahase, Nobuaki Kabuto
  • Publication number: 20060012883
    Abstract: The present invention discloses the structure of the array lens that at least any one of the diagonal size, vertical size and lateral size of lens cell is set to almost 1/(4.5 or more) for each corresponding size of the display elements, the structure that the diagonal size of lens cell is set to almost 0.18 inch or less, the structure that the total number of lens cells is set to almost 240 or more and the structure that the lens focal distance of lens cell is set to almost 30 mm or less.
    Type: Application
    Filed: September 23, 2005
    Publication date: January 19, 2006
    Inventors: Satoshi Ohuchi, Masahiko Yatsu, Taro Imahase, Tomohiro Miyoshi, Yasuo Otsuka, Takesuke Maruyama
  • Patent number: 6963453
    Abstract: The present invention discloses the structure of the array lens that at least any one of the diagonal size, vertical size and lateral size of lens cell is set to almost 1/(4.5 or more) for each corresponding size of the display elements, the structure that the diagonal size of lens cell is set to almost 0.18 inch or less, the structure that the total number of lens cells is set to almost 240 or more and the structure that the lens focal distance of lens cell is set to almost 30 mm or less.
    Type: Grant
    Filed: April 13, 2004
    Date of Patent: November 8, 2005
    Assignee: Hitachi, Ltd.
    Inventors: Satoshi Ohuchi, Masahiko Yatsu, Taro Imahase, Tomohiro Miyoshi, Yasuo Otsuka, Takesuke Maruyama
  • Publication number: 20050243280
    Abstract: An image display device has three reflective image display elements for red, green and blue to form an optical image according to a video signal from light output from a light source, and an optical system to supply light onto the display elements and to combine and output the light reflected from the display elements. The image display device includes a first polarity converting unit to convert luminous flux from the light source to S polarized light, a first polarized beam splitter, and second polarized beam splitter. The reflective image display element for green is provided in a vicinity of the first polarized beam splitter, and the light reflected by the first polarized beam splitter and input to the reflective image display element for green is S polarized light. The light output from the reflective image display element for green permeates the first and second polarized beam splitters.
    Type: Application
    Filed: July 7, 2005
    Publication date: November 3, 2005
    Inventors: Satoshi Ouchi, Taro Imahase, Tomohiro Miyoshi, Fukuyasu Abe