Patents by Inventor Katsunari Ohta

Katsunari Ohta 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: 4400455
    Abstract: A layered electrophotographic photoconductor whose charge generation layer comprises a bisazo pigment selected from the group consisting of the bisazo pigments represented by the following general formula (1) and whose charge transport layer contains a charge transport material selected from the group consisting of the hydrazone compounds represented by the following general formula (2): ##STR1## wherein A represents --C.sub.6 H.sub.4 --Cl(o), --C.sub.6 H.sub.4 --Cl(m), --C.sub.6 H.sub.4 --Br(o), --C.sub.6 H.sub.4 --Br(m), --C.sub.6 H.sub.4 --F(o), --C.sub.6 H.sub.4 --F(m), --C.sub.6 H.sub.4 --F(p), or --C.sub.6 H.sub.4 --I(m); ##STR2## wherein R.sup.1 represents a methyl group, an ethyl group, a 2-hydroxyethyl group or a 2-chloroethyl group; R.sup.2 represents a methyl group, an ethyl group, a benzyl group or a phenyl group; and R.sup.3 represents hydrogen, chloride, bromide, an alkyl group with one to four carbon atoms, an alkoxy group with one to four carbon atoms, a dialkylamino group, or a nitro group.
    Type: Grant
    Filed: November 30, 1981
    Date of Patent: August 23, 1983
    Assignee: Ricoh Company Ltd.
    Inventors: Mitsuru Hashimoto, Kiyoshi Sakai, Katsunari Ohta, Akio Kojima