Patents by Inventor Keiichi Nagahashi

Keiichi Nagahashi 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: 4226928
    Abstract: In a laminated photosensitive material for electrophotography, an intermediate layer comprising, incorporated in a binder, phthalocyanine or a phthalocyanine derivative and a polycyclic aromatic nitro compound at a specific ratio is formed on an electrically conductive substrate, and a top layer comprising an organic polymeric photoconductor and the above polycyclic aromatic nitro compound at a specific ratio is laminated on the intermediate layer. In this photosensitive material, the dark decay speed is controlled in a range suitable for application to the repeated copying operation and the residual potential left on the exposure area can be reduced to a negligible level. Accordingly, occurrence of fogging is prevented and the toner transfer efficiency is improved. Further, this photosensitive material has improved mechanical, chemical and electric durabilities, and therefore, the life of the photosensitive material is remarkably prolonged.
    Type: Grant
    Filed: January 5, 1978
    Date of Patent: October 7, 1980
    Assignee: Mita Industrial Company, Ltd.
    Inventors: Toru Nakazawa, Keiichi Nagahashi, Tatsuo Aizawa
  • Patent number: 4214907
    Abstract: In a photosensitive material for electrophotography, an intermediate layer comprising an organic polymeric photoconductor and a polycyclic aromatic nitro compound at a specific ratio is formed on an electrically conductive substrate, and a top layer comprising, incorporated in a binder, phthalocyanine or phthalocyanine derivative and the above polycyclic aromatic nitro compound at a specific ratio is laminated on the intermediate layer. In this photosensitive material, the dark decay speed is controlled in a range suitable for application to the repeated copying operation and the residual potential left on the exposure area can be reduced to a negligible level. Accordingly, occurrence of fogging is prevented and the toner transfer efficiency is improved. Further, this photosensitive material has improved mechanical, chemical and electric durabilities, and therefore, the life of the photosensitive material is remarkably prolonged.
    Type: Grant
    Filed: January 5, 1978
    Date of Patent: July 29, 1980
    Assignee: Mita Industrial Company, Ltd.
    Inventors: Toru Nakazawa, Keiichi Nagahashi, Tatsuo Aizawa