Patents by Inventor Mikio Kakui

Mikio Kakui 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: 6265123
    Abstract: An electrophotographic photosensitive element is provided with a photosensitive layer containing a charge generating substance and a charge transport substance on a conductive support. X-type metal-free phthalocyanine and a disazo compound are contained as a charge generating substance. With the photosensitive element, sufficient sensitivity is achieved so as to cause virtually no problem, and it is possible to reduce possibility of causing an instable electrostatic property such as a reduction in a charge potential and an increase in a remained potential, even in the case of frequent reuse.
    Type: Grant
    Filed: March 22, 2000
    Date of Patent: July 24, 2001
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Mikio Kakui, Tatsuhiro Morita, Rikiya Matsuo, Sayaka Fujita, Kazushige Morita, Yoshihide Shimoda
  • Patent number: 6136484
    Abstract: Highly sensitive and highly durable electrophotographic photoreceptors which generate faultless images can be produced by forming the under-coating layer on the conductive support and forming the photoreceptive layer on the layer. The under-coating layer contains dendritic titanium oxide. The under-coating layer contains the dendritic titanium oxide of which the surface is coated with (a) metal oxide(s) and/or (an) organic compound(s). The photoreceptive layer contains a phthalocyanine pigment, and the under-coating layer contains dendritic or needle-like titanium oxide of which the surface is coated with (a) metal oxide(s) and/or (an) organic compound(s). The photoreceptive layer contains a phthalocyanine pigment, and the under-coating layer contains dendritic or needle-like titanium oxide, of which the surface is coated with (a) metal oxide(s) and/or (an) organic compound(s), and an alcohol soluble polyamide resin.
    Type: Grant
    Filed: June 1, 1999
    Date of Patent: October 24, 2000
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Satoshi Katayama, Yoshihide Shimoda, Makoto Kurokawa, Mikio Kakui, Hiroko Ishibashi, Tadashi Nakamura, Tatsuhiro Morita, Masayuki Sakamoto, Kazushige Morita, Tomoko Kanazawa, Akihiko Kawahara
  • Patent number: 6090514
    Abstract: The present invention provides an electrophotosensitive material comprising a conductive substrate and a single photosensitive layer containing a stilbene derivative (hole transferring material) represented by the general formula (1): ##STR1## (wherein R.sup.1, R.sup.2, R.sup.5 and R.sup.6 are the same or different and represent an alkyl group, an alkoxy group, an aryl group, an aralkyl group or a halogen atom; m, n, p and q are the same or different and represent an integer of 0 to 3, with the proviso that m and n represent a different integer when substituents represented by R.sup.1 and R.sup.2 are the same and that p and q represent a different integer when substituents represented by R.sup.5 and R.sup.6 are the same; and R.sup.3 and R.sup.4 are the same or different and represent a hydrogen atom or an alkyl group) and an electron transferring material, which is provided on the conductive substrate.
    Type: Grant
    Filed: August 20, 1999
    Date of Patent: July 18, 2000
    Assignee: Mita Industrial Co., Ltd.
    Inventors: Mikio Kakui, Hirofumi Kawaguchi, Akihiko Kawahara, Kazunari Hamasaki, Yoshio Inagaki, Ayako Yashima
  • Patent number: 5843606
    Abstract: In accordance with the present invention, there is provided a phenanthrylenediamine derivative represented by the general formula (1). The derivative is excellent in the electric charge transferring capability, the compatibility with a binding resin and the stability, thereby providing a photosensitive material which is highly sensitive and excellent in the durability. ##STR1## ?wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4 each represent a halogen atom, an alkyl group, an alkoxy group or an aryl group; and a, b, c and d each represent an integer from 0 to 5!.
    Type: Grant
    Filed: September 18, 1997
    Date of Patent: December 1, 1998
    Assignee: Mita Industrial Co., Ltd.
    Inventors: Eiichi Miyamoto, Mikio Kakui, Hideo Nakamori, Yukikatsu Imanaka, Yasuyuki Hanatani
  • Patent number: 5830615
    Abstract: The present invention provides a novel naphthylenediamine derivative which is superior in electric charge transferring capability, compatibility with binding resin and stability, and an electrophotosensitive material which has a higher sensitivity and an excellent durability. The above naphthylenediamine derivative is represented by the following general formula (1), and the electrophotosensitive material is formed by providing a photosensitive layer having this naphthylenediamine derivative as an electric charge transferring material on a conductive substrate. ##STR1## wherein R.sup.1 to R.sup.4, R.sup.5a to R.sup.5f and a to d are as defined.
    Type: Grant
    Filed: May 29, 1997
    Date of Patent: November 3, 1998
    Assignee: Mita Industrial Co., Ltd.
    Inventors: Eiichi Miyamoto, Mikio Kakui, Hideo Nakamori, Yukikatsu Imanaka, Tadashi Sakuma, Maki Uchida, Hiroaki Iwasaki, Yasuyuki Hanatani, Nariaki Tanaka, Yuka Nakamura
  • Patent number: 5767315
    Abstract: The present invention provides a novel naphthylenediamine derivative which is superior in electric charge transferring capability, compatibility with binding resin and stability. The above naphthylenediamine derivative is represented by the following general formula (1) ##STR1## wherein R.sup.1 to R.sup.4, R.sup.5a to R.sup.5f and a to d are as defined.
    Type: Grant
    Filed: October 5, 1995
    Date of Patent: June 16, 1998
    Assignee: Mita Industrial Co., Ltd.
    Inventors: Eiichi Miyamoto, Mikio Kakui, Hideo Nakamori, Yukikatsu Imanaka, Tadashi Sakuma, Maki Uchida
  • Patent number: 5550290
    Abstract: The present invention relates to a benzidine derivative represented by the general formula (1): ##STR1## wherein R.sup.1 to R.sup.6, m and n are as defined in the present specification. The benzidine derivative improves durability and heat resistance of a membrane containing the same while maintaining high hole transferring capability. Therefore, an electrophotosensitive material, which comprises a photosensitive layer containing the benzidine derivative, has high sensitivity and is superior in durability and heat resistance.
    Type: Grant
    Filed: September 28, 1994
    Date of Patent: August 27, 1996
    Assignee: Mita Industrial Co. Ltd.
    Inventors: Yasufumi Mizuta, Masashi Tanaka, Nariaki Muto, Toshiyuki Fukami, Hideo Nakamori, Mikio Kakui, Sakae Saito, Hiroshi Shiomi, Keisuke Sumida, Maki Uchida
  • Patent number: 5514508
    Abstract: The present invention provides an electrophotosensitive material having an improved sensitivity in comparison with a conventional one, obtained by combining a trinitrofluorenoneimine derivative represented by the formula (1): ##STR1## wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4 and R.sup.5 are the same or different and indicate a hydrogen atom, an alkyl group, an alkoxy group, an aryl group which may contain a substituent, an aralkyl group which may contain a substituent, or a halogen atom! as an electron transferring material with a prescribed electric charge generating material or hole transferring material.
    Type: Grant
    Filed: May 19, 1995
    Date of Patent: May 7, 1996
    Assignee: Mita Industrial Co., Ltd.
    Inventors: Toshiyuki Fukami, Hideo Nakamori, Hiroshi Shiomi, Hirofumi Kawaguchi, Hisakazu Uegaito, Nariaki Muto, Mikio Kakui, Keisuke Sumida, Sakae Saito, Maki Uchida
  • Patent number: 5312713
    Abstract: An information recording medium comprises a recording layer including a mixture of organic polysilane and oxo metallic phthalocyanine pigment. Information is recorded by adding heat or light to the recording layer. In a method for recording information onto the information recording medium, a decoloring reaction of oxo metallic phthalocyanine pigment is used which is caused by heating the recording layer to a temperature equal to or higher than a pyrolyzing point of organic polysilane.
    Type: Grant
    Filed: September 14, 1993
    Date of Patent: May 17, 1994
    Assignee: Mita Industrial Co., Ltd.
    Inventors: Masaaki Yokoyama, Mikio Kakui
  • Patent number: 5264266
    Abstract: An information recording medium comprises a recording layer including a mixture of organic polysilane and oxo metallic phthalocyanine pigment. Information is recorded by adding heat or light to the recording layer. In a method for recording information onto the information recording medium, a decoloring reaction of oxo metallic phthalocyanine pigment is used which is caused by heating the recording layer to a temperature equal to or higher than a pyrolyzing point of organic polysilane.
    Type: Grant
    Filed: September 9, 1991
    Date of Patent: November 23, 1993
    Assignee: Mita Industrial Co., Ltd.
    Inventors: Masaaki Yokoyama, Mikio Kakui
  • Patent number: 5184895
    Abstract: An optical sensor has a photosensitive portion which has a first layer including oxo metallic phthalocyanine pigment and a second layer consisting of organic polysilane and shows a sensing of light with a change of color. The optical sensor can also be used as a thermal sensor.
    Type: Grant
    Filed: September 4, 1991
    Date of Patent: February 9, 1993
    Assignee: MITA Industrial Co., Ltd.
    Inventors: Masaaki Yokoyama, Mikio Kakui
  • Patent number: 5153088
    Abstract: This invention provides an electrophotosensitive material comprising a conductive substrate and a photosensitive layer formed thereon, the photosensitive layer includes a perylene compound (I) and an X-type metal-free phtalocyanine as a charge-generating ingredient and a diamine derivative (II) as a charge-transferring ingredient in the binding resin. This electrophotosensitive material is especially superior in sensitivity and reproductivity. Formulas (I) and (II) are defined as follows: ##STR1## wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6, R.sup.7, R.sup.8, R.sup.9 l, m, n, o and p have the same meanings as defined in the text of the specification.
    Type: Grant
    Filed: February 28, 1990
    Date of Patent: October 6, 1992
    Assignee: Mita Industrial Co., Ltd.
    Inventors: Nariaki Muto, Tatsuo Maeda, Hirotsugu Nishikawa, Mikio Kakui, Keisuke Sumida, Toru Nakazawa
  • Patent number: 5087544
    Abstract: The present invention provides an electrophotosensitive material comprising a conductive substrate, and a photosensitive layer provided on the conductive substrate and containing a m-phenylenediamine compound represented by the general formula [I]: ##STR1## (wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4 and R are the same as defined before). The present electrophotosensitive material has high sensitivity and is easy to be manufactured.
    Type: Grant
    Filed: March 26, 1990
    Date of Patent: February 11, 1992
    Assignee: Mita Industrial Co., Ltd.
    Inventors: Nariaki Muto, Mikio Kakui, Keisuke Sumida, Toru Nakazawa, Kazuo Matsumoto
  • Patent number: 5059503
    Abstract: The present invention provides an electrophotosensitive material containing the diamine derivative represented by the following general formula (I) and at least one selected from the group consisting of the hydrazone compound, fluorene compound and m-phenylenediamine compound. ##STR1## wherein R.sup.5 to R.sup.9, l, m, n, o and p are as defined.
    Type: Grant
    Filed: March 29, 1990
    Date of Patent: October 22, 1991
    Assignee: Mita Industrial Co., Ltd.
    Inventors: Nariaki Muto, Tatsuo Maeda, Toshihiko Nishiguchi, Mikio Kakui, Keisuke Sumida, Toru Nakazawa