Patents by Inventor Takashi Chuman

Takashi Chuman 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: 6023124
    Abstract: An electron emission device exhibits a high electron emission efficiency. The device includes an electron supply layer of metal or semiconductor, an insulator layer formed on the electron supply layer, and a thin-film metal electrode formed on the insulator layer. The insulator layer is made of an amorphous dielectric substance and has a film thickness of 50 nm or greater and has an amorphous phase with an average grain size of 5 to 100 nm as a major component and a polycrystal phase as a minor component. When an electric field is applied between the electron supply layer and the thin-film metal electrode, the electron emission device emits electrons.
    Type: Grant
    Filed: February 27, 1998
    Date of Patent: February 8, 2000
    Assignee: Pioneer Electric Corporation
    Inventors: Takashi Chuman, Shingo Iwasaki
  • Patent number: 5990605
    Abstract: An electron emission device includes: a semiconductor layer; a porous semiconductor; and a thin-film metal electrode which are layered in turn. The electrode faces a vacuum space. The porous semiconductor layer has at least two or more of porosity-changed layers which have porosities which are different from each other in the thickness direction. The electron emission device emits electrons when an electric field is applied between the semiconductor layer and the thin-film metal electrode. An insulator layer made of a material selected from silicon oxide or silicon nitride may be formed between the porous semiconductor layer and the thin-film metal electrode. Si skeletons of the porous semiconductor layer are oxidized or nitrided.
    Type: Grant
    Filed: March 20, 1998
    Date of Patent: November 23, 1999
    Assignee: Pioneer Electronic Corporation
    Inventors: Takamasa Yoshikawa, Kiyohide Ogasawara, Hiroshi Ito, Masataka Yamaguchi, Shingo Iwasaki, Nobuyasu Negishi, Takashi Chuman
  • Patent number: 5986390
    Abstract: An electron emission device exhibits a high electron emission efficiency. The device includes an electron supply layer of metal or semiconductor, an SiO.sub.2 insulator layer formed on the electron supply layer, and a thin-film metal electrode formed on the insulator layer. The peak intensity ratio of a Raman spectrum for 3-fold rings of SiO.sub.2 of the insulator layer to 4-fold rings or 5 or more-fold rings thereof is equal to or greater than 20%. When an electric field is applied between the electron supply layer and the thin-film metal electrode, the electron emission device emits electrons.
    Type: Grant
    Filed: March 3, 1998
    Date of Patent: November 16, 1999
    Assignee: Pioneer Electronic Corporation
    Inventors: Takashi Chuman, Takamasa Yoshikawa
  • Patent number: 5635268
    Abstract: An optical recording medium is provided with: a first substrate of optically transparent type; a first recording layer formed on one surface of the first substrate, which includes phthalocyanine dye; a second substrate of optically transparent type; a second recording layer formed on one surface of the second substrate which includes phthalocyanine dye; a first elastic body layer formed on a surface of the first recording layer at a side opposite to the first substrate; a second elastic body layer formed on a surface of the second recording layer at a side opposite to the second substrate; and a bonding layer formed between the first elastic body layer and the second elastic body layer.
    Type: Grant
    Filed: June 19, 1995
    Date of Patent: June 3, 1997
    Assignee: Pioneer Electronic Corporation
    Inventors: Takako Miyake, Shingo Iwasaki, Yasushi Araki, Takashi Chuman, Satoru Tanaka, Atsushi Yoshizawa, Fumio Matsui
  • Patent number: 5580631
    Abstract: An optical recording medium comprises a light transmissive substrate, a record film formed on a surface of the base plate, the record film containing phthalocyanine as a coloring matter, a light-reflection film formed on a surface of the record film, and a protection film formed on a surface of the light-reflection film, the protection film having a thickness capable of preventing the light-reflection film from braking by a deformation thereof in directions to the light-reflection film and the protection film due to a formation of a pit in the record film.
    Type: Grant
    Filed: November 5, 1993
    Date of Patent: December 3, 1996
    Assignee: Pioneer Electronic Corporation
    Inventors: Toshiyuki Miyadera, Takashi Chuman, Takashi Yamada, Fumio Matsui
  • Patent number: 5494778
    Abstract: An optical recording medium which has a recording medium and a light reflective film on a substrate. A top coat film made of organic material for adjusting reflectivity is formed on a surface of the substrate opposite to the other surface on which the at least one of the recording film and the light reflective film is formed. A reflectivity is remarkably enhanced without any adverse affect to a tracking error and an error rate. Also, it is easy to form the top coat. The top coat has an excellent weatherproof property.
    Type: Grant
    Filed: September 24, 1993
    Date of Patent: February 27, 1996
    Assignee: Pioneer Electronic Corporation
    Inventors: Takashi Chuman, Takashi Yamada, Shingo Iwasaki, Toshiyuki Miyadera
  • Patent number: 5478623
    Abstract: An optical recording medium is provided with: a light transmissive substrate; a recording film formed of an organic dye with 2,2,3,3-tetrafluoro-1-propanol having pH of not less than 6.0 as a solvent, on a surface of the substrate; a reflective film formed on a surface of the recording film; and a protection film formed on a surface of the reflective film.
    Type: Grant
    Filed: November 7, 1994
    Date of Patent: December 26, 1995
    Assignee: Pioneer Electronic Corporation
    Inventors: Shingo Iwasaki, Taishi Tsuji, Takashi Chuman, Satoru Tanaka, Shuichi Yanagisawa, Fumio Matsui
  • Patent number: 5455094
    Abstract: An optical recording medium has a substrate having a groove, a recording film of phthalocyanine coloring matter and provided on the substrate, a light reflection film on the recording film, and a protection film on the light reflection film. The depth of the groove is between 800 .ANG. and 1100 .ANG..
    Type: Grant
    Filed: November 4, 1993
    Date of Patent: October 3, 1995
    Assignee: Pioneer Electronic Corporation
    Inventors: Toshiyuki Miyadera, Takashi Chuman, Takashi Yamada, Fumio Matsui
  • Patent number: 5431977
    Abstract: An optical recording medium has a substrate and a recording film provided on the substrate. The recording film contains organic coloring matter and polyvinylbutyral. The organic coloring matter and polyvinylbutyral are dissolved by a solvent and coated on the substrate to form the recording film.
    Type: Grant
    Filed: October 19, 1993
    Date of Patent: July 11, 1995
    Assignee: Pioneer Electronic Corporation
    Inventors: Toshiyuki Miyadera, Takashi Chuman, Takashi Yamada, Fumio Matsui
  • Patent number: 5391413
    Abstract: A recordable optical recording medium having sufficiently high reflectance and modulation factor to insure consistent reproduction on CD players. The optical recording medium of the present invention has a light-transparent substrate having pregrooves formed in the face of one surface, a light-absorbing layer formed on the pregrooves, a light-reflecting layer formed on said light-absorbing layer, wherein the pregrooves have a depth of .lambda./6.5 n-.lambda./2.5 n (where .lambda. is the wavelength of recording or reproducing light in nanometers, and n is the refractive index of the substrate) and a width of 0.35-0.47 .mu.m.
    Type: Grant
    Filed: December 17, 1991
    Date of Patent: February 21, 1995
    Assignee: Pioneer Electronic Corporation
    Inventors: Shuichi Yanagisawa, Tatsuro Sakai, Satoru Tanaka, Takashi Chuman, Yasushi Araki, Fumio Matsui
  • Patent number: 5370970
    Abstract: A WORM optical disk that not only has a sufficiently improved reflectance to permit the setting of higher RF signal levels but that also permits the setting of higher levels for the tracking error signals to insure consistent performance in operation. This WORM optical disk of the present invention comprises a substrate 1 that has grooves 2 formed in its surface and that is coated with a dye film 3 which, in turn, is coated with a reflecting film 4, wherein the part of the dye film 3 which is formed on the lands 5 of the substrate 1 and a portion of that part of the dye film 3 which is formed in the grooves 2 are subjected to irradiation to effect color fading in the irradiated dye regions.
    Type: Grant
    Filed: July 19, 1993
    Date of Patent: December 6, 1994
    Assignee: Pioneer Electronic Corporation
    Inventors: Satoru Tanaka, Takashi Chuman, Yasushi Araki
  • Patent number: 5336584
    Abstract: An optical recording medium comprises a light transmissive substrate, a light absorption layer provided on the light transmissive substrate and a light reflecting layer provided on the light absorption layer. The light absorption layer contains a cyanine type dye represented by a following structural formula: ##STR1## and a quencher represented by a following general formula: ##STR2## wherein R.sub.1, R.sub.2, R.sub.3 and R.sub.4 denote hydrogen or substituent group, respectively. A protective layer may be further provided on the light reflecting layer for protecting the same.
    Type: Grant
    Filed: April 24, 1991
    Date of Patent: August 9, 1994
    Assignee: Pioneer Electronic Corporation
    Inventors: Shuichi Yanagisawa, Tatsuro Sakai, Takashi Chuman, Yasushi Araki, Fumio Matsui
  • Patent number: 5328802
    Abstract: An optical recording medium comprises a light transmissive substrate, a light absorption layer provided on the light transmissive substrate and a light reflecting layer provided on the light absorption layer. The light absorption layer contains a cyanine type dye represented by a following structural formula: ##STR1## and a quencher represented by a following general formula: ##STR2## wherein R.sub.1, R.sub.2, R.sub.3 and R.sub.4 denote hydrogen or substituent group, respectively. A protective layer may be further provided on the light reflecting layer for protecting the same.
    Type: Grant
    Filed: April 24, 1991
    Date of Patent: July 12, 1994
    Assignee: Pioneer Electronic Corporation
    Inventors: Shuichi Yanagisawa, Tatsuro Sakai, Takashi Chuman, Yasushi Araki, Fumio Matsui
  • Patent number: 5328741
    Abstract: A recordable optical recording medium having a sufficiently high reflectance and modulation factor to comply with the CD specifications. The light-absorbing layer in the optical recording medium has a first cyanine dye having a light absorption band in the wavelength region of recording or reproducing light, and a second cyanine dye having a light absorption band in the wavelength range shorter than the first cyanine dye and having a smaller light absorption in the wavelength region of recording or reproducing light. The second cyanine dye is contained in the light-absorbing layer in an amount larger than the first cyanine dye.
    Type: Grant
    Filed: December 17, 1991
    Date of Patent: July 12, 1994
    Assignee: Pioneer Electronic Corporation
    Inventors: Shuichi Yanagisawa, Tatsuro Sakai, Satoru Tanaka, Takashi Chuman, Yasushi Araki, Fumio Matsui
  • Patent number: 5326679
    Abstract: A writable recording medium having reduced jitter, improved performance on repeated reproduction, improved light resistance, and sensitivity controllability is disclosed, in which a light-absorbing layer thereof contains (D-1) a cyanine dye having an absorption band in the wavelength region of light for recording or reproduction, (D-2) a cyanine dye having an absorption band in a shorter wavelength region than that of cyanine dye (D-1) and having a smaller absorption than that of cyanine dye (D-1) in the wavelength region of light for recording or reproduction, (Q-1) a quencher for preventing photo-deterioration of cyanine dyes, and (Q-2) a quencher selected from an azo compound and a diphenylamine compound, the weight ratio of cyanine dye (D-2) to cyanine dye (D-1), taken as .alpha., being from 1 to 3, the weight ratio of quencher (Q-1) to quencher (Q-2), taken as .beta., being from 0.
    Type: Grant
    Filed: May 27, 1993
    Date of Patent: July 5, 1994
    Assignee: Pioneer Electronic Corporation
    Inventors: Shuichi Yanagisawa, Atsushi Yoshizawa, Tatsuro Sakai, Satoru Tanaka, Makoto Okano, Takashi Chuman, Yasushi Araki, Taishi Tsuji, Fumio Matsui
  • Patent number: 5238723
    Abstract: An optical recording medium, comprising: a light transparent substrate, a light absorbing layer disposed on the light transparent substrate, a light reflection layer disposed on the light absorbing layer, and a protection layer disposed on the light reflection layer, wherein the protection layer has been formed by curing a photo-setting resin which is capable of providing a glass transition point of not lower than 110.degree. C., a shrinkage factor of not larger than 8%, and a water vapor permeability of not higher than 110 g/m.sup.2 .multidot.24 H after being cured. The optical recording medium having the above structure is capable of showing stable performances, even in an environment of high humidity.
    Type: Grant
    Filed: April 2, 1992
    Date of Patent: August 24, 1993
    Assignee: Pioneer Electronic Corporation
    Inventors: Atsushi Yoshizawa, Takashi Chuman, Yasushi Araki, Shuichi Yanagisawa, Fumio Matsui
  • Patent number: 5204220
    Abstract: An optical recording medium comprises a light transmissive substrate, a light absorption layer provided on the light transmissive substrate and a light reflecting layer provided on the light absorption layer. The light absorption layer contains a cyanine type dye represented by a following structural formula: ##STR1## and a quencher represented by a following general formula: ##STR2## wherein R.sub.1, R.sub.2, R.sub.3 and R.sub.4 denote hydrogen or substituent group, respectively. A protective layer may be further provided on the light reflecting layer for protecting the same.
    Type: Grant
    Filed: April 24, 1991
    Date of Patent: April 20, 1993
    Assignee: Pioneer Electronic Corporation
    Inventors: Shuichi Yanagisawa, Tatsuro Sakai, Takashi Chuman, Yasushi Araki, Fumio Matsui