Patents by Inventor Keishi Saito

Keishi Saito 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: 5093704
    Abstract: An improved semiconductor device such as an improved graded band gap transistor and an improved graded band gap diode, characterized by comprising a non-single-crystal material containing silicon atom, a band gap adjusting atom and a localized level reducing atom and having a region in which a band gap being continuously graded at least one position other than junction position and only one of a conduction band and a valence band being continuously graded. It gives a significant improvement in both the frequency characteristic and the photoresponse.
    Type: Grant
    Filed: September 28, 1989
    Date of Patent: March 3, 1992
    Assignee: Canon Kabushiki Kaisha
    Inventors: Keishi Saito, Yasushi Fujioka
  • Patent number: 4940642
    Abstract: There are provided on improved light receiving member for use in electrophotography and a process for the production thereof.
    Type: Grant
    Filed: January 26, 1989
    Date of Patent: July 10, 1990
    Assignee: Canon Kabushiki Kaisha
    Inventors: Shigeru Shirai, Keishi Saito, Takayoshi Arai, Minoru Kato, Yasushi Fujioka
  • Patent number: 4898798
    Abstract: An improved photosensitive member for use in electrophotography which comprises a substrate and a light receiving layer having a charge carrier generation layer and a charge carrier transportation layer composed of a carbonic film the nucleus of which matrix being carbon atom, which contains 40 atomic % or less of hydrogen atom and which possesses an optical band gap of 1.5 eV or more and an electric conductivity of 10.sup.-11 .OMEGA..sup.-1 cm.sup.-1 or less.It is always and substantially stable regardless of the changes in use environments and it enables to make highly resolved images with a clear half-tone which are highly dense and quality at high speed.
    Type: Grant
    Filed: September 25, 1987
    Date of Patent: February 6, 1990
    Assignee: Canon Kabushiki Kaisha
    Inventors: Masao Sugata, Tohru Den, Susumu Ito, Keiji Hirabayashi, Keiko Ikoma, Noriko Kurihara, Kuniji Osabe, Tatsuo Takeuchi, Hiroshi Satomura, Yoshihiro Oguchi, Akio Maruyama, Keishi Saito
  • Patent number: 4892800
    Abstract: An improved photosensitive member for use in electrophotography which is characterized by having a substrate and a photoconductive layer comprising a carbonic film, the nucleus of which matrix being carbon atom, which contains 30 atomic % or less of hydrogen atom and at least one selected from the elements of Group III and Group V of the Periodic Table, and which has an optical band gap of more than 1.5 eV and an electrical conductivity of 10.sup.-11 .OMEGA..sup.-1 cm.sup.-1 or less.It is always and substantially stable regardless of the changes in use environments and it enables to make highly resolved images with a clear half-tone which are highly dense and quality at high speed.
    Type: Grant
    Filed: September 18, 1987
    Date of Patent: January 9, 1990
    Assignee: Canon Kabushiki Kaisha
    Inventors: Masao Sugata, Tatsuo Takeuchi, Hiroshi Satomura, Yoshihiro Oguchi, Akio Maruyama, Keishi Saito, Tohru Den, Susumu Ito, Keiji Hirabayashi, Keiko Ikoma, Noriko Kurihara, Kuniji Osabe
  • Patent number: 4887134
    Abstract: An improved semiconductor device such as an improved graded band gap transistor and an improved graded band gap diode, characterized by comprising a non-single-crystal material containing silicon atom, a band gap adjusting atom and a localized level reducing atom and having a region in which a band gap continuously graded at least one position other than junction position and only one of a conduction band and a valence band being continuously graded. It gives a significant improvement in both the frequency characteristic and the photoresponse.
    Type: Grant
    Filed: September 21, 1987
    Date of Patent: December 12, 1989
    Assignee: Canon Kabushiki Kaisha
    Inventors: Keishi Saito, Yasushi Fujioka
  • Patent number: 4845001
    Abstract: Improved light receiving members which are characterized by having an special surface layer formed of a non-monocrystalline material containing tetrahedrally bonded boron nitride or a non-monocrystalline material containing said boron nitride and trihedrally bonded boron nitride in mingled state or by having an especial surface layer constituted with a lower layer formed of a non-monocrystalline material containing tetrahedrally bonded boron nitride and an upper layer formed of a non-monocrystalline material containing tetrahedrally bonded boron nitride and trihedrally bonded boron nitride in mingled state. The improved light receiving members excel particularly in moisture resistance, repeating use characteristic, electrical voltage withstanding property environmental use characteristic and durability.
    Type: Grant
    Filed: April 29, 1987
    Date of Patent: July 4, 1989
    Assignee: Canon Kabushiki Kaisha
    Inventors: Tetsuya Takei, Keishi Saito, Tatsuyuki Aoike, Yasushi Fujioka
  • Patent number: 4824749
    Abstract: There are provided an improved light receiving member for use in electrophotography and a process for the production thereof. The light receiving member comprises a substrate usable for electrophotography and a light receiving layer constituted by a charge injection inhibition layer formed of an amorphous or polycrystalline material containing silicon atom as the main constituent and an element for controlling the conductivity, a photoconductive layer formed of an amorphous material containing silicon atom as the main constituent and at least one kind selected from hydrogen atom and halogen atom and a surface layer formed of a polycrystalline material containing silicon atom, carbon atom and hydrogen atom. The polycrystalline material is a polycrystalline material prepared by introducing a precursor capable of contributing to formation of the layer and an active species reactive with the precursor separately into a film deposition space and chemically reacting them.
    Type: Grant
    Filed: March 23, 1987
    Date of Patent: April 25, 1989
    Assignee: Canon Kabushiki Kaisha
    Inventors: Shigeru Shirai, Keishi Saito, Takayoshi Arai, Minoru Kato, Yasushi Fujioka
  • Patent number: 4818655
    Abstract: There is provided an improved light receiving member for use in electrophotography comprising a substrate for electrophotography and a light receiving layer constituted by an absorption layer for light of long wavelength formed of a polycrystal material containing silicon atoms and germanium atoms, a photoconductive layer formed of an amorphous material containing silicon atoms as the main constituent atoms and a surface layer formed of an amorphous material containing silicon atoms, carbon atoms and hydrogen atoms, the amount of the hydrogen atoms contained in the surface layer being in the range of from 1.times.10.sup.-3 to 40 atomic %. The light receiving layer may have a charge injection inhibition layer or/and a contact layer.
    Type: Grant
    Filed: February 26, 1987
    Date of Patent: April 4, 1989
    Assignee: Canon Kabushiki Kaisha
    Inventors: Shigeru Shirai, Keishi Saito, Takayoshi Arai, Minoru Kato, Yasushi Fujioka
  • Patent number: 4804604
    Abstract: An electrophotographic member has an electrophotographic substrate and a light receiving layer having (i) a 0.01 to 10 .mu.m thick charge injection inhibition layer, (ii) a 1 to 100 .mu.m thick photoconductive layer and (iii) a 0.003 to 30 .mu.m thick surface layer. The charge injection inhibition layer includes a polycrystal material containing silicon atoms as the main constituent, 30 to 5.times.10.sup.4 atomic ppm of a conductivity controlling element of Group III and Group V elements uniformly or nonuniformly distributed in the thickness direction and 1-40 atomic % of hydrogen atoms and/or halogen atoms. The photoconductive layer is an amorphous semiconductor material containing silicon atoms as the main constituent and 1-40 atomic % of hydrogen atoms and/or halogen atoms. The surface layer includes an amorphous material: A--(Si.sub.x C.sub.1-x).sub.y :H.sub.1-y wherein x is 0.1 to 0.99999 and y is 0.6 to 0.999.
    Type: Grant
    Filed: February 18, 1987
    Date of Patent: February 14, 1989
    Assignee: Canon Kabushiki Kaisha
    Inventors: Shigeru Shirai, Keishi Saito, Takayoshi Arai, Minoru Kato, Yasushi Fujioka
  • Patent number: 4803093
    Abstract: Process for preparing a functional film deposited on a substrate having practically applicable characteristics which is usable as a photoconductive member in semiconductor device, image input line sensor, image pickup device on the like by generating an active species by subjecting a gaseous substance capable of being activated to generate said active species to the action of activating energy in an active species generating and transporting space leading to a film forming space containing the substrate;simultaneously generating a precursor by subjecting a gaseous substance capable of generating said precursor to the action of activating energy in a precursor generating and transporting space located separately from and within the active species generating and transporting space and open in a downstream region of that space; andintroducing the resulting active species and precursor into the film forming space to chemically react to form the functional deposited film on the substrate in the absence of plasma.
    Type: Grant
    Filed: March 24, 1986
    Date of Patent: February 7, 1989
    Assignee: Canon Kabushiki Kaisha
    Inventors: Shunichi Ishihara, Keishi Saito, Shunri Oda, Isamu Shimizu
  • Patent number: 4798167
    Abstract: An apparatus for the preparation of a photoelectric conversion layer for a photoelectromotive force member includes:(a) a film-forming chamber having an inner space in which a substrate holder for a substrate is provided;(b) an exhaust pipe connected to the film-forming chamber and through a main valve to an exhaust pump;(c) a concentric triplicate conduit connected through a nozzle to the film-forming chamber.
    Type: Grant
    Filed: May 1, 1987
    Date of Patent: January 17, 1989
    Assignee: Canon Kabushiki Kaisha
    Inventors: Shunichi Ishihara, Keishi Saito, Shunri Oda, Isamu Shimizu
  • Patent number: 4795691
    Abstract: This is provided an improved light receiving member having at least a photoconductive layer constituted with A-Si(H,X) series material and a surface layer constituted with A-Si(C,O,N)(H,X) for use in electrophotography, etc. which is characterized in that the atom(C,O,N) is contained in the surface layer in a state that the concentration of the atom(C,O,N) is grown increasingly starting from the position of the interface between the surface layer and the photoconductive layer while leaving a portion corresponding to a refractive index difference (.DELTA.n) [.DELTA.n.ltoreq.0.62] between the refractive index of the surface layer and that of the photoconductive layer which can be disregarded in the image-making process toward the free surface of the surface layer.
    Type: Grant
    Filed: April 15, 1987
    Date of Patent: January 3, 1989
    Assignee: Canon Kabushiki Kaisha
    Inventors: Tetsuya Takei, Tatsuyuki Aoike, Minoru Kato, Keishi Saito
  • Patent number: 4788120
    Abstract: There is provided an improved light receiving member for use in electrophotography comprising a substrate for electrophotography and a light receiving layer constituted by a photoconductive layer and a surface layer, the photoconductive layer being formed of an amorphous material containing silicon atoms as the main constituent atoms and at least one kind selected from hydrogen atoms and halogen atoms and the surface layer being formed of an amorphous material containing silicon atoms, carbon atoms and hydrogen atoms, and the amount of the hydrogen atoms contained in the surface layer being in the range of 41 to 70 atomic %.
    Type: Grant
    Filed: February 16, 1988
    Date of Patent: November 29, 1988
    Assignee: Canon Kabushiki Kaisha
    Inventors: Shigeru Shirai, Keishi Saito, Takayoshi Arai, Minoru Kato, Yasushi Fujioka
  • Patent number: 4738913
    Abstract: There is provided an improved light receiving member for use in electrophotography comprising a substrate for electrophotography and a light receiving layer constituted by a charge injection inhibition layer, a photoconductive layer and a surface layer, the charge injection inhibition layer being formed of an amorphous material containing silicon atoms as the main constituent atoms and an element for controlling the conductivity, the photoconductive layer being formed of an amorphous material containing silicon atoms as the main constituent atoms and at least one kind selected from hydrogen atoms and halogen atoms and the surface layer being formed of an amorphous material containing silicon atoms, carbon atoms and hydrogen atoms, and the amount of the hydrogen atoms contained in the surface layer being in the range from 41 to 70 atomic %.
    Type: Grant
    Filed: January 21, 1987
    Date of Patent: April 19, 1988
    Assignee: Canon Kabushiki Kaisha
    Inventors: Shigeru Shirai, Keishi Saito, Takayoshi Arai, Minoru Kato, Yasushi Fujioka
  • Patent number: 4702934
    Abstract: A process and an apparatus for preparing an electrophotographic photosensitive member with the use of an active species and a precursor in the absence of a plasma.
    Type: Grant
    Filed: March 24, 1986
    Date of Patent: October 27, 1987
    Assignee: Canon kabushiki Kaisha
    Inventors: Shunichi Ishihara, Keishi Saito, Shunri Oda, Isamu Shimizu
  • Patent number: 4689093
    Abstract: Process for preparing a photoelectromotive force member by forming a photoelectric conversion layer on a substrate by: (a) generating an active species by the action of microwave energy on a substance in a space leading to a film forming space containing a substrate; (b) generating a precursor by the action of microwave energy on a substance in a space situated within the space for generating the active species; and (c) introducing the resulting active species and precursor into the film forming space to chemically react them and to form the photoelectric conversion layer.
    Type: Grant
    Filed: March 24, 1986
    Date of Patent: August 25, 1987
    Assignee: Canon Kabushiki Kaisha
    Inventors: Shunichi Ishihara, Keishi Saito, Shunri Oda, Isamu Shimizu
  • Patent number: 4356455
    Abstract: An amplifier circuit in which the non-linear distortion of the amplifier transistors caused by non-linear base-emitter input and output characteristics is eliminated without the use of negative feedback. A first transistor and a second transistor of opposite conductivity type are coupled with the output of the first transistor connected to the base of the second transistor and with an input signal applied to the base of the first transistor. Currents are applied to the first and second transistors, such as with the current mirror circuit, in such a manner that the ratio of the currents is a predetermined constant value. Bias voltages are applied to the circuit such that the ratio of the collector-emitter voltage of the first transistor to the collector-emitter voltage of the second transistor is the reciprocal of the predetermined constant value.
    Type: Grant
    Filed: September 17, 1980
    Date of Patent: October 26, 1982
    Assignee: Pioneer Electronic Corporation
    Inventors: Akio Ozawa, Susumu Sueyoshi, Keishi Saito, Kikuo Ishikawa, Kiyomi Yatsuhashi, Satoshi Ishii, Masamichi Yumino