Patents by Inventor Yuzuru Fukuda

Yuzuru Fukuda 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: 5075187
    Abstract: An electrophotographic photoreceptor is disclosed which comprises a support having provided thereon a charge generating layer containing silicon as a main component and a charge transport layer containing as a main component an oxide of at least one element selected from aluminum, zirconium, and tantalum, said charge generating layer and charge transport layer being adjacent to each other. The photoreceptor has a charging capacity of about 50 V/.mu.m or more and a rate of dark decay of 15%/sec or less.
    Type: Grant
    Filed: August 27, 1990
    Date of Patent: December 24, 1991
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Ken-ichi Karakida, Yuzuru Fukuda, Susumu Honma, Masayuki Nishikawa, Shigeru Yagi
  • Patent number: 5059501
    Abstract: An electrophotographic photoreceptor having a photosensitive layer essentially made of amorphous silicon formed over a support, and a surface layer made of amorphous silicon formed over the photosensitive layer. The amorphous silicon of the photosensitive layer includes boron of 0.1-5 ppm, and the amorphous silicon of the surface layer includes nitrogen. The layers of material formed over the support include a charge blocking layer.
    Type: Grant
    Filed: October 10, 1989
    Date of Patent: October 22, 1991
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Shigeru Yagi, Masato Ono, Noriyoshi Takahashi, Masayuki Nishikawa, Yuzuru Fukuda, Kenichi Karakida
  • Patent number: 5008170
    Abstract: A photoreceptor for electrophotography, comprising: a photoconductive layer substantially composed of amorphous silicon, and first, second and third surface layers substantially composed of amorphous silicon added with nitrogen atom, those layers being formed on a support. The thickness d.sub.1, d.sub.2 and d.sub.3 of the first, second and third surface layers satisfies the following relation: d.sub.2 >d.sub.1 and d.sub.2 >d.sub.3, and the nitrogen concentrations c.sub.1, c.sub.2 and c.sub.3 of said first, second and third surface layers satisfy the following relation: c.sub.3 >c.sub.2 >c.sub.1.
    Type: Grant
    Filed: June 23, 1989
    Date of Patent: April 16, 1991
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Kenichi Karakida, Shigeru Yagi, Yuzuru Fukuda, Masayuki Nishikawa, Te N. Roh, Noriyoshi Takahashi, Masato Ono, Masaki Yokoi, Yumiko Komori
  • Patent number: 4965154
    Abstract: An electrophotographic photoreceptor comprising a photoconductive layer, a first surface layer and a second surface layer formed in sequence on a support, said photoconductive layer being substantially composed of amorphous silicon, and each of said first and second surface layers being substantially composed of nitrogen-doped amorphous silicon, the concentration of nitrogen atoms in the second surface layer being higher than that in the first surface layer. The photoconductive layer is doped with atoms of an element of group III, or in at least a part of the photoconductive layer doped with germanium atoms in place of the element of group III.
    Type: Grant
    Filed: June 19, 1989
    Date of Patent: October 23, 1990
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Kenichi Karakida, Shigeru Yagi, Yuzuru Fukuda, Masayuki Nishikawa, Te Nam Roh, Noriyoshi Takahashi, Masato Ono
  • Patent number: 4965164
    Abstract: A method for producing an electrophotographic photoreceptor is disclosed, which comprises the steps of forming a charge transporting layer comprising aluminum oxide on a substrate and then forming thereon a charge generating layer comprising mainly amorphous silicon, or alternatively forming a charge generating layer comprising mainly amorphous silicon on a substrate and then forming thereon a charge transporting layer comprising aluminum oxide, wherein the charge transporting layer is formed using a compound containing aluminum by the ion plating method while maintaining the substrate at 50.degree. C. or more.
    Type: Grant
    Filed: February 7, 1989
    Date of Patent: October 23, 1990
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Yuzuru Fukuda, Masayuki Nishikawa
  • Patent number: 4960662
    Abstract: A positively and negatively chargeable electrophotographic photoreceptor is disclosed, comprising a substrate having thereon a charge blocking layer, an amorphous silicon photoconductive layer, and an amorphous silicon nitride surface layer provided in that order, wherein the charge blocking layer comprises of amorphous silicon nitride and the amorphous silicon photoconductive layer comprises of an i-type amorphous silicon containing 0.05 to 5.0 ppm of boron.
    Type: Grant
    Filed: January 5, 1989
    Date of Patent: October 2, 1990
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Masayuki Nishikawa, Yumiko Komori, Masaki Yokoi, Masato Ono, Noriyoshi Takahashi, Yuzuru Fukuda, Shigeru Yagi, Ken-ichi Karakida
  • Patent number: 4932859
    Abstract: An electrophotographic photoreceptor having excellent dark resistance is disclosed, which comprises a photoconductive layer and a surface layer formed successively on a conductive substrate, wherein the photoconductive layer mainly comprises hydrogen-containing amorphous silicon, and the surface layer comprises amorphous carbon which contains not more than 50 atomic percent of hydrogen. The surface layer contains phosphorous or boron as a dopant and/or comprises two sublayers where the sublayer has a lower hydrogen content than the lower sublayer.
    Type: Grant
    Filed: July 5, 1988
    Date of Patent: June 12, 1990
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Shigeru Yagi, Masayuki Nishikawa, Te Nam Roh, Ken-ichi Karakida, Masahito Tokuhiro, Noriyoshi Takahashi, Yuzuru Fukuda
  • Patent number: 4923773
    Abstract: An electrophotographic photoreceptor comprising a support, a charge blocking layer, a first photoconductive layer composed of at least amorphous silicon, a second photoconductive layer composed of at least boron-containing amorphous silicon, a surface layer composed of at least nitrogenated amorphous silicon, the surface layer having an interface for contacting the second photoconductive layer, the surface layer including a lower region corresponding to an area not greater than approximately 100 .ANG. away from the interface, the lower region having a ratio of not less than 0.5 parts of nitrogen atoms for one part of silicon atoms, the nitrogen ratio of the lower region and the boron content of the second photoconductive layer corresponding to the relation B.gtoreq.10.sup.(9N-5.5) where B is the boron content in PPM and N is the ratio of nitrogen atoms to silicon atoms.
    Type: Grant
    Filed: October 18, 1988
    Date of Patent: May 8, 1990
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Shigeru Yagi, Masato Ono, Noriyoshi Takahashi, Masayuki Nishikawa, Yuzuru Fukuda, Kenichi Karakida