Patents by Inventor Yuuji Takana

Yuuji Takana 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).

  • Photoreceptor, image forming method and image forming apparatus using the photoreceptor, process cartridge using the photoreceptor and coating liquid for the photoreceptor
    Patent number: 7381511
    Abstract: A photoreceptor including an electroconductive substrate; a photosensitive layer; and optionally a protective layer, wherein an outermost layer thereof includes a filler, an organic compound having an acid value of from 10 to 700 mg KOH/g and at least one compound selected from the group consisting of compounds having the following formulae (1) and (2): wherein R1 (R3) and R2 (R4) independently represent a substituted or an unsubstituted aromatic hydrocarbon group, or a substituted or an unsubstituted alkyl group, and optionally share bond connectivity to form a heterocyclic group including a nitrogen atom; Ar1 (Ar3) and Ar2 (Ar4) independently represent a substituted or a unsubstituted aromatic ring group; k (K) and m (M) independently represent 0 or an integer of from 1 to 3, wherein k (K) and m (M) are not 0 at the same time; and n (n?) represents an integer of from 1 to 3.
    Type: Grant
    Filed: June 1, 2004
    Date of Patent: June 3, 2008
    Assignee: Ricoh Company, Ltd.
    Inventors: Takaaki Ikegami, Tomoyuki Shimada, Yasuo Suzuki, Nozomu Tamoto, Hidetoshi Kami, Yuuji Takana
  • Photoreceptor, image forming method and image forming apparatus using the photoreceptor, process cartridge using the photoreceptor and coating liquid for the photoreceptor
    Publication number: 20050008957
    Abstract: A photoreceptor including an electroconductive substrate; a photosensitive layer; and optionally a protective layer, wherein an outermost layer thereof includes a filler, an organic compound having an acid value of from 10 to 700 mg KOH/g and at least one compound selected from the group consisting of compounds having the following formulae (1) and (2): wherein R1 (R3) and R2 (R4) independently represent a substituted or an unsubstituted aromatic hydrocarbon group, or a substituted or an unsubstituted alkyl group, and optionally share bond connectivity to form a heterocyclic group including a nitrogen atom; Ar1 (Ar3) and Ar2 (Ar4) independently represent a substituted or a unsubstituted aromatic ring group; k (K) and m (M) independently represent 0 or an integer of from 1 to 3, wherein k (K) and m (M) are not 0 at the same time; and n (n?) represents an integer of from 1 to 3.
    Type: Application
    Filed: June 1, 2004
    Publication date: January 13, 2005
    Inventors: Takaaki Ikegami, Tomoyuki Shimada, Yasuo Suzuki, Nozomu Tamoto, Hidetoshi Kami, Yuuji Takana