Patents by Inventor Fujiko Koyama

Fujiko Koyama 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: 6398365
    Abstract: A projection display apparatus (100) is formed by a light source (4) radiating white light w, a collimator lens (5) that converts condensed light flux from the light source (4) to collimated light flux, a cold mirror (6) for eliminating unwanted infrared light included in the white light w, an integrator that makes the intensity distribution of the illumination light on an object to be illuminated uniform, a reflective mirror (8) that reflects light flux from the integrator (7) at a prescribed angle, a polarizer (9) that polarizes separated light of each wavelength band, a spatial light modulation section (10), a coupling prism (11), and a projection lens (12).
    Type: Grant
    Filed: March 8, 2000
    Date of Patent: June 4, 2002
    Assignee: Victor Company of Japan, Limited
    Inventors: Ryusaku Takahashi, Shintaro Nakagaki, Tsutou Asakura, Fujiko Koyama
  • Patent number: 6174060
    Abstract: A color separating/light guiding optics comprises two independent dichroic mirrors, reflection mirrors and correcting lenses. A horizontal plane region occupied by these optical components is entirely involved in a horizontal plane region occupied by a light modulating/color compositing/image projecting optics. A red beam is guided along a detoured optical path extending across a dead space below a projection lens. Although the optical path length of the red beam becomes longer than those of the blue beam and the green beam, the detoured optical path provides a sufficient space for installing the correcting lenses. The substantial optical path lengths of three primary color beams can be equalized with each other by the provision of these correcting lenses.
    Type: Grant
    Filed: August 25, 1998
    Date of Patent: January 16, 2001
    Assignee: Victor Company of Japan, Ltd.
    Inventors: Hirofumi Imaoka, Satoru Moriya, Tetsuji Suzuki, Fujiko Koyama, Ryusaku Takahashi, Yasuo Ishizaka, Motomu Takada
  • Patent number: 6049410
    Abstract: A spatial light modulator and a lighting system used in, for example, projection displays are provided. The lighting system has a polarizing plate optically disposed in parallel to a light modulating layer of the spatial light modulator, thereby orienting the polarization of readout light beams incident on the spatial light modulator in the same direction to increase the contrast of images projected on a screen. The spatial light modulator is provided with a coupling prism having a side surface opposed to an entrance surface on which the readout light beams are incident. The side surface is so inclined inward as to allow stray light in the coupling prism to go out of the coupling prism without being reflected, thereby eliminating a decrease in contrast of images with a screen caused by the stray light.
    Type: Grant
    Filed: December 8, 1998
    Date of Patent: April 11, 2000
    Assignee: Victor Company of Japan, Ltd.
    Inventors: Shintaro Nakagaki, Tsutou Asakura, Fujiko Koyama, Tatsuru Kobayashi
  • Patent number: 5486878
    Abstract: In a color image display apparatus, light beams intensity modulated by a green color image signal are deflected by an ocillating mirror, and then focused on a photo-conductive layer (PCL) member of a light-written type spacial light modulation element (SLM) through two focusing lenses for light write operation. Light beams intensity modulated by a time-axis compressed time-divisional image signal of two remaining colors (red and blue) are deflected by another mirror oscillated simultaneously with the ocillating mirror, and then focused on a PCL member of a SLM of the same type through two focusing lenses for light write operation. A read light beam is resolved into the light of the green wave length band and the lights of red and blue wave length bands, respectively, and then given to the SLMs, respectively for light read operation. The two read light beams reflected by the SLMs are synthesizing, and then projected on a screen through a common projection lens.
    Type: Grant
    Filed: September 23, 1994
    Date of Patent: January 23, 1996
    Assignee: Victor Company of Japan, Ltd.
    Inventors: Ichiro Negishi, Tetsuji Suzuki, Fujiko Koyama, Yuji Uchiyama, Hiroyuki Bonde, Toshio Konno, Ryusaku Takahashi, Toshiaki Shou