Patents by Inventor Katsugi Kitatani

Katsugi Kitatani 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: 5106712
    Abstract: A novel electrophotographic photoreceptor is provided comprising on an electrically conductive support a layer containing a charge carrier-transporting compound and a charge carrier-generating compound or a charge carrier-transporting compound-containing layer and a charge-generating compound-containing layer, characterized in that as said charge carrier-generating compound there is contained a novel bisazo compound represented by the general formula (1-A), (1-B) or (1-C):Cp--N.dbd.N--Ar.sup.1 --C.tbd.C--.sub.n Ar.sup.2 --N.dbd.N--Cp (1-A)wherein Ar.sup.1 and Ar.sup.2 each represents an arylene group, divalent condensed polycyclic aromatic group or divalent heterocyclic aromatic group; Cp represents a coupler residue; and n represents an integer 2 or 3;Cp--N.dbd.N--Ar.sup.1 --C.tbd.C--Ar.sup.2 --C.tbd.C--Ar.sup.3 --C.tbd.C--Ar.sup.4 --N.dbd.N--Cp (1-B)wherein Ar.sup.1, Ar.sup.2, Ar.sup.3 and Ar.sup.
    Type: Grant
    Filed: July 6, 1990
    Date of Patent: April 21, 1992
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Katsugi Kitatani, Naonori Makino, Satoshi Hoshi
  • Patent number: 5093219
    Abstract: A novel electrophotographic photoreceptor is provided comprising a light-sensitive layer containing at least one of acetylene compounds represented by general formula (I) provided on an electrically conductive support:Ar.sup.1 C.tbd.C--AR.sup.3 --C.tbd.C--AR.sup.2 (I)wherein Ar.sup.1 and Ar.sup.2 each represents an aromatic carbon ring or aromatic heterocyclic group; and Ar.sup.3 represents an arylene group, divalent condensed polycyclic aromatic group or divalent aromatic heterocyclic group.
    Type: Grant
    Filed: August 17, 1990
    Date of Patent: March 3, 1992
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Naonori Makino, Satoshi Hoshi, Katsugi Kitatani
  • Patent number: 4882249
    Abstract: Disclosed are a photoconductive composition containing a new tetrakisazo compound of the following formula (1) and an electrophotographic photoreceptor having a photosensitive layer which contains the tetrakisazo compound of the formula (1): ##STR1## wherein R.sup.11, R.sup.12, A, Ar.sup.1, Ar.sup.2, Ar.sup.3, Ar.sup.4, Ar.sup.5, and Ar.sup.6 are defined hereinbefore. The electrophotographic photoreceptor has both high sensitivity and high durability, and the sensitivity thereof is barely lowered even after repeated use.
    Type: Grant
    Filed: September 12, 1988
    Date of Patent: November 21, 1989
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Katsugi Kitatani, Satoshi Hoshi
  • Patent number: 4871637
    Abstract: Disclosed are a photoconductive composition containing a new bisazo compound of the following formula (1) and an electrophotographic photoreceptor having a photosensitive layer which contains the bisazo compound of the formula (1): ##STR1## wherein Z, B.sub.1, B.sub.2, A, and L are defined hereinafter. The electrophotographic photoreceptor has both high sensitivity and high durability, and the sensitivity thereof is barely lowered even after repeated use.
    Type: Grant
    Filed: September 19, 1988
    Date of Patent: October 3, 1989
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Katsugi Kitatani, Satoshi Hoshi
  • Patent number: 4756993
    Abstract: An electrophotographic photoreceptor is disclosed, comprising a light-transmitting conductive support having provided thereon a light-transmitting electrophotographic photosensitive layer, said support having further provided on the side opposite to the photosensitive layer a light scattering layer comprising an inorganic fine powder and a binder or a light absorbing layer comprising a near infrared absorbing dye and a binder. The photoreceptor can provide a sharp image free from interference fringe-like non-uniformity of density even when a laser is used as a light source of exposure.
    Type: Grant
    Filed: January 27, 1987
    Date of Patent: July 12, 1988
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Katsugi Kitatani, Kenji Sano, Keishi Kato, Shigeru Ohno
  • Patent number: 4719165
    Abstract: The present invention provides a process for preparation of a charge-regulatory agent characterized by reacting an amino acid with a titanium compound in an organic solvent to form a reaction mixture and further reacting the resultant reaction mixture with water which is equimolar or more to said titanium compound, and a liquid developer for development of an electrostatic image comprising a dispersion of resin-containing toner particles dispersion in a carrier solution having an electric resistance of 10.sup.9 .OMEGA..multidot.cm or more and a dielectric constant of 3.5 or less and containing said charge-regulatory agent prepared as mentioned above.When an electrostatic latent image is developed with the present liquid developer containing the special charge-regulatory agent, an image of excellent resolving power, good half-tone reproduction and excellent gradation may be obtained without the occurence of any image flow.
    Type: Grant
    Filed: September 24, 1986
    Date of Patent: January 12, 1988
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Katsugi Kitatani, Hiroaki Yokoya, Nobuo Suzuki, Masataka Murata
  • Patent number: 4614699
    Abstract: A liquid developer for electrostatic images which comprises at least one charge controlling agent selected from the group consisting of compounds represented by formula (I) or (II) and complex salts containing a molecular structure shown by the formula (I) or (II): ##STR1## wherein R.sup.1 and R.sup.2 each represents a hydrogen atom, an alkyl and substituted alkyl group, an aryl and a substituted aryl group, an aralkyl group, an aliphatic acyl group, an aromatic acyl group, an alkylsulfonyl group, an arylsulfonyl group, R.sup.1 and R.sup.2 represent identical group or different groups, or R.sup.1 and R.sup.2 together form a heterocyclic ring with the nitrogen atom in the formulae, and when one of R.sup.1 and R.sup.
    Type: Grant
    Filed: July 16, 1984
    Date of Patent: September 30, 1986
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Katsugi Kitatani, Masataka Murata, Hiroaki Yokoya, Nobuo Suzuki