Patents by Inventor Takeo Oshiba

Takeo Oshiba 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: 5591558
    Abstract: An electrostatic image forming method is disclosed. The photoreceptor containing an organic photosensitive material has a layer containing fine particles at the photoreceptor surface; toner has at least binder resin, coloring agent, and releasing agent made of polyolefines in which the ratio, Mz/Mn, is is 3-20, and Mz is 20,000-70,000 wherein Mz is Z-average molecular weight in terms of polypropylene and Mn is the number average molecular weight in terms of polypropylene. No offset phenomenon occurs, and a stable image having no fogging and no black-spots can be formed for a long period of time by the invention.
    Type: Grant
    Filed: February 20, 1996
    Date of Patent: January 7, 1997
    Assignee: Konica Corporation
    Inventors: Hiroshi Yamazaki, Takeo Oshiba, Yoshihiko Etoh
  • Patent number: 5589314
    Abstract: Disclosed is an image forming method using an electrophotographic photoreceptor comprising the steps of:(1) charging the electrophotographic photoreceptor, wherein said electrophotographic photoreceptor comprising a conductive support and provided thereon, a carrier generation layer and a carrier transportation layer, said carrier generation layer comprising a carrier generation material represented by formula 1 or 2 and having X-ray diffraction pattern having peaks at 6.3.degree..+-.0.2.degree., 12.4.degree..+-.0.2.degree., 25.3.degree..+-.0.2.degree. and 27.1.degree..+-.0.2.degree. in Bragg angle (2.theta.) when using Cu-K.alpha. ray as a X-ray radiation source in which said peak of 12.4.degree..+-.0.2.degree. has a maximum intensity and has a half width of 0.65.degree. or more; no peak being present at 11.5.degree..+-.0.2.degree.,(2) imagewise exposing the charged photoreceptor for an exposure time of 1.times.10.sup.-4 to 3.times.10.sup.
    Type: Grant
    Filed: June 15, 1995
    Date of Patent: December 31, 1996
    Assignee: Konica Corporation
    Inventors: Yoshihiko Etoh, Takeo Oshiba, Asao Matsushima, Hirofumi Hayata, Tomoo Sakimura, Tomoko Suzuki, Akira Kinoshita
  • Patent number: 5434027
    Abstract: The present invention is directed to a photoreceptor having an electroconductive support, a barrier layer, a charge generation layer and a charge transport layer, all formed on the support in this order, wherein the barrier layer consists of an alcohol-soluble copolymerized polyamide resin, the charge generation layer contains a compound represented by formula I or II, and the charge transport layer contains a polycarbonate resin having a molecular weight of not less than 100,000, ##STR1## wherein Z represents a groups of atoms necessary to form a substituted or unsubstituted divalent aromatic ring.
    Type: Grant
    Filed: December 21, 1993
    Date of Patent: July 18, 1995
    Assignee: Konica Corporation
    Inventors: Takeo Oshiba, Yoshihiko Etoh, Asao Matsushima, Yoshiaki Takei
  • Patent number: 5403691
    Abstract: Disclosed is a method for preparing an electrophotographic photoreceptor comprising the steps of:(a) preparing a dispersion solution comprising a carrier generation material, a binder resin and an organic solvent; and(b) coating said dispersion solution on a conductive support; wherein said carrier generation material is a fluorenone type bisazo pigment represented by Formula F.sub.1, and main component of said organic solvent is selected from the group consisting of a ketone type solvent, an ester type solvent and an alcohol type each having a branched alkyl group: ##STR1## wherein X.sub.1, X.sub.2, p, q, and A, are defined as in the Specification.
    Type: Grant
    Filed: April 20, 1993
    Date of Patent: April 4, 1995
    Assignee: Konica Corporation
    Inventors: Takeo Oshiba, Yoshihiko Etoh, Yoshiaki Takei
  • Patent number: 5320921
    Abstract: An electrophotographic photoreceptor is disclosed. The photoreceptor comprises a conductive layer and provided thereon, a photoreceptor layer comprising a carrier generation layer containing 100 parts by weight of a polycyclic quinone compound and 0.
    Type: Grant
    Filed: September 3, 1992
    Date of Patent: June 14, 1994
    Assignee: Konica Corporation
    Inventors: Takeo Oshiba, Yoshio Takizawa
  • Patent number: 5270140
    Abstract: An electrophotographic photoreceptors containing a bisstyryl compound represented by the following formula I is disclosed. ##STR1## R.sup.0 and/or R.sup.00 represent methyl group, and the rest of Rs represent hydrogen atom or an alkyl group having 1 to 4 carbon atoms; and Ar.sup.1 and Ar.sup.2 represent each an aromatic group.
    Type: Grant
    Filed: March 9, 1992
    Date of Patent: December 14, 1993
    Assignee: Konica Corporation
    Inventors: Naoto Abew, Naohiro Hirose, Hirofumi Hayata, Syozo Mitsui, Shinichi Suzuki, Osamu Sasaki, Yoshio Takizawa, Takeo Oshiba