Patents by Inventor Akira Imai

Akira Imai 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: 5495049
    Abstract: A triarylamine compound useful as a charge transport material of an electrophotographic photoreceptor, which represented by formula (I) ##STR1## wherein Ar.sub.1 and Ar.sub.2 each represents a phenyl group or a condensed ring group.
    Type: Grant
    Filed: March 22, 1994
    Date of Patent: February 27, 1996
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Katsumi Nukada, Akira Imai, Ryosaku Igarashi
  • Patent number: 5476968
    Abstract: A N,N'-bis(p-hydroxymethylphenyl)benzidine compound having the following formula (I): ##STR1## wherein R.sub.1 represents a hydrogen atom, a methyl group or a methoxy group; R.sub.2 represents an alkyl group having one to four carbon atoms, a methoxy group or an ethoxy group; and R.sub.3 represents a hydrogen atom or a methyl group, is intended to be used as a charge transporting material of an electrophotographic photoreceptor. A method for preparing the compound includes formylating a N,N'-diphenylbenzidine derivative having the following formula (II): ##STR2## by the conventional Viismeier reaction to obtain a N,N'-bis(p-formylphenyl) benzidine derivative of the following formula (III): ##STR3## and reducing the derivative with a boron hydride salt or an aluminum hydride salt.
    Type: Grant
    Filed: August 22, 1994
    Date of Patent: December 19, 1995
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Akira Imai, Katsumi Nukada
  • Patent number: 5463043
    Abstract: A novel dichlorotin phthalocyanine crystal having distinct diffraction peaks at 8.5.degree., 11.2.degree., 14.5.degree., and 27.2.degree. of the Bragg angles (2.theta..+-.0.2) in the X-ray diffraction spectrum; a process for producing the dichlorotin phthalocyanine crystal, comprising mechanically grinding a known dichlorotin phthalocyanine crystal together with an inorganic salt, followed by, if desired, a solvent treatment; an electrophotographic photoreceptor containing, in the photosensitive layer thereof, the dichlorotin phthalocyanine crystal; and a coating composition for producing an electrophotographic photoreceptor, comprising the dichlorotin phthalocyanine crystal, a binder resin, and an acetic ester solvent. The photoreceptor exhibits high sensitivity and excellent durability. The coating composition maintains the dichlorotin phthalocyanine crystal in its desired form either while being prepared or after being coated.
    Type: Grant
    Filed: May 10, 1994
    Date of Patent: October 31, 1995
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Katsumi Nukada, Akira Imai, Katsumi Daimon, Masakazu Iijima, Kiyokazu Mashimo, Yasuo Sakaguchi, Ichiro Takegawa
  • Patent number: 5463044
    Abstract: A process for preparing chlorogallium phthalocyanine comprising the steps of: reacting gallium trichloride and phthalonitrile or diiminoisoindoline in an aromatic hydrocarbon solvent; and treating the resulting chlorogallium phthalocyanine with a second solvent different from the aromatic hydrocarbon solvent.
    Type: Grant
    Filed: August 18, 1993
    Date of Patent: October 31, 1995
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Katsumi Nukada, Akira Imai, Masakazu Iijima
  • Patent number: 5459004
    Abstract: A process for preparing hydroxygallium phthalocyanine crystals showing intense diffraction peaks at Bragg angles (2.theta..+-.0.2) of 7.5.degree., 25.1.degree., and 28.3.degree. with respect to CuK.sub..alpha. characteristic X-rays which comprises mechanically grinding hydroxygallium phthalocyanine and then treating the grains with a solvent is disclosed. The hydroxygallium phthalocyanine crystals obtained by the process of the present invention has a novel crystal form and exhibits high sensitivity and excellent durability on repeated use as well as crystal form stability. The electrophotographic photoreceptor prepared by using the resulting hydroxygallium phthalocyanine exhibits excellent electrophotographic characteristics.
    Type: Grant
    Filed: March 29, 1993
    Date of Patent: October 17, 1995
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Katsumi Daimon, Katsumi Nukada, Akira Imai, Masakazu Iijima, Toru Ishii
  • Patent number: 5416207
    Abstract: A dichlorotin phthalocyanine crystal showing, in the X-ray diffractometry using a CuK.sub..alpha. ray, a peak at a Bragg angle (2.theta..+-.0.2.degree.) of 28.2.degree. with any other peak(s) observed at a Bragg angle(s) between 25.degree. and 30.degree. having an intensity of not more than 30% of that of the peak at 28.2.degree.. The crystal is useful as a photoconductive material having sensitivity in the longer wavelength region. The electrophotographic photoreceptor containing the crystal exhibits high sensitivity and excellent durability.
    Type: Grant
    Filed: November 1, 1993
    Date of Patent: May 16, 1995
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Akira Imai, Katsumi Nukada, Satsumi Daimon, Masakazu Iijima, Toru Ishii, Yasuo Sakaguchi, Kiyokazu Mashimo
  • Patent number: 5393629
    Abstract: Crystals of hydroxygallium phthalocyanine, a method of preparing the crystals, a photoconductive material containing the crystals, and an electrophotographic photoreceptor having the material. The photoreceptor has excellent electrophotographic characteristics. The crystals of hydroxygallium phthalocyanine have distinct diffraction peaks at (i) 7.5.degree., 9.9.degree., 12.5.degree., 16.3.degree., 18.6.degree., 25.1.degree. and 28.3.degree., or (ii) 7.7.degree., 16.5.degree., 25.1.degree. and 26.6.degree., or (iii) 7.9.degree., 16.5.degree., 24.4.degree. and 27.6.degree., or (iv) 7.0.degree., 7.5.degree., 10.5.degree., 11.7.degree., 12.7.degree., 17.3.degree., 18.1.degree., 24.5.degree., 26.2.degree. and 27.1.degree., or (v) 6.8.degree., 12.8.degree., 15.8.degree. and 26.0.degree. or (vi) 7.4.degree., 9.9.degree., 25.0.degree., 26.0.degree., and 28.2.degree. of the Bragg angle (2.theta..+-.0.2) in the X-ray diffraction spectrum.
    Type: Grant
    Filed: March 12, 1993
    Date of Patent: February 28, 1995
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Katsumi Nukada, Katsumi Daimon, Yasuo Sakaguchi, Kazuo Yamasaki, Masakazu Iijima, Michiaki Takahashi, Kazuhiro Koseki, Akira Imai, Kiyokazu Mashimo, Toru Ishii, Fumio Ojima, Masayuki Nishikawa, Ryosaku Igarashi
  • Patent number: 5391441
    Abstract: Disclosed are phase-shifting masks wherein restriction of light transmission at edges of phase-shifting patterns (e.g., at an edge where a 180.degree. phase-shifting pattern ends on a light transmission region) is avoided, and methods of making such masks. The region of the transparent pattern of the mask, under the edge of the phase-shifting pattern, is made wider than that of the transparent pattern in other regions; moreover, an additional phase-shifting layer is provided at the edge of the phase-shifting pattern, the additional phase-shifting layer having a phase-shift preferably of less than 90.degree., to avoid a 180.degree. phase shift at the edge. Also disclosed is a phase-shifting mask having repaired defects, and a method for repairing defects in phase-shifting masks, using an additional phase-shifting layer.
    Type: Grant
    Filed: February 19, 1993
    Date of Patent: February 21, 1995
    Assignee: Hitachi, Ltd.
    Inventors: Akira Imai, Norio Hasegawa
  • Patent number: 5362589
    Abstract: A phthalocyanine mixed crystal comprising a halogenated indium phthalocyanine and a halogenated gallium phthalocyanine and an electrophotographic photoreceptor containing the phthalocyanine mixed crystal. The phthalocyanine mixed crystal is a charge generating material which provides an electrophotographic photoreceptor excellent in sensitivity, stability on repeated use, and environmental stability.
    Type: Grant
    Filed: November 2, 1993
    Date of Patent: November 8, 1994
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Katsumi Nukada, Akira Imai, Katsumi Daimon, Masakazu Iijima
  • Patent number: 5362591
    Abstract: There is disclosed a mask which includes a first phase shifter layer and a second phase shifter layer formed on the first phase shifter layer and has a structure capable of easily effecting highly precise control of the phase of exposure light and correction for a defect in the phase shifter layers. There are also disclosed a method of manufacturing the mask and a method of forming by use of the mask a pattern which has a smaller local error in pattern dimension and is free of a defect.
    Type: Grant
    Filed: October 5, 1990
    Date of Patent: November 8, 1994
    Assignee: Hitachi Ltd. et al.
    Inventors: Akira Imai, Norio Hasegawa, Hiroshi Fukuda, Toshihiko Tanaka
  • Patent number: 5358813
    Abstract: Crystals of chlorogallium phthalocyanine, having distinct diffraction peaks at (i) 7.4.degree., 16.6.degree., 25.5.degree. and 28.3.degree., (ii) 6.8.degree., 17.3.degree., 23.6.degree. and 26.9.degree., or (iii) 8.7.degree. to 9.2.degree., 17.6.degree., 24.0.degree., 27.4.degree. and 28.8.degree. of the Bragg angle (2.theta..+-.0.2) to a CuK.alpha. characteristic X-ray; a photoconductive material for electrophotographic photoreceptor comprising the chlorogallium phthalocyanine; and an electrophotographic photoreceptor comprising an electroconductive support having thereon a light-sensitive layer containing at least one or more of chlorogallium phthalocyanine crystals. The electrophotographic photoreceptor has excellent sensitivity and durability.
    Type: Grant
    Filed: January 12, 1993
    Date of Patent: October 25, 1994
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Masakazu Iijima, Katsumi Nukada, Katsumi Daimon, Akira Imai, Toru Ishii, Yasuo Sakaguchi, Kiyokazu Mashimo, Ichiro Takegawa
  • Patent number: 5338636
    Abstract: A novel dichlorotin phthalocyanine crystal having distinct diffraction peaks at 8.5.degree., 11.2.degree., 14.5.degree., and 27.2.degree. of the Bragg angles (2.theta..+-.0.2) in the X-ray diffraction spectrum; process for producing the dichlorotin phthalocyanine crystal, comprising mechanically grinding a known dichlorotin phthalocyanine crystal together with an inorganic salt, followed by, if desired, a solvent treatment; an electrophotographic photoreceptor containing, in the photosensitive layer thereof, the dichlorotin phthalocyanine crystal; and a coating composition for producing an electrophotographic photoreceptor, comprising the dichlorotin phthalocyanine crystal, a binder resin, and an acetic ester solvent. The photoreceptor exhibits high sensitivity and excellent durability. The coating composition maintains the dichlorotin phthalocyanine crystal in its desired form either while being prepared or after being coated.
    Type: Grant
    Filed: January 6, 1993
    Date of Patent: August 16, 1994
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Katsumi Nukada, Akira Imai, Katsumi Daimon, Masakazu Iijima, Kiyokazu Mashimo, Yasuo Sakaguchi, Ichiro Takegawa
  • Patent number: 5336578
    Abstract: A novel phthalocyanine mixed crystal comprising a dihalogenotin phthalocyanine and a halogenogallium phthalocyanine and an electrophotographic photoreceptor containing the same are disclosed. The phthalocyanine mixed crystal preferably has an intense X-ray diffraction peak at a Bragg angle (2.theta..+-.0.2.degree.) of 26.9. The phthalocyanine mixed crystal is useful as a charge generating material which provides an electrophotographic photoreceptor excellent in sensitivity, stability on repeated use, and environmental stability.
    Type: Grant
    Filed: January 8, 1993
    Date of Patent: August 9, 1994
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Katsumi Nukada, Akira Imai, Katsumi Damion, Masakazu Iijima
  • Patent number: 5328807
    Abstract: A comb-like or dot-like phase shifter pattern is added to a phase shifter used in phase shifting mask technology, which is then exposed onto a wafer. This enables the formation of extremely fine line patterns or space patterns having widths different from each other simultaneously. Further, when two reticles are disposed such that phase shifter patterns disposed therein intersect each other and are exposed consecutively onto a wafer, a fine hole pattern or dot pattern can be formed at a position where the phase shifter patterns intersect each other.
    Type: Grant
    Filed: June 7, 1991
    Date of Patent: July 12, 1994
    Assignee: Hitichi, Ltd.
    Inventors: Toshihiko Tanaka, Norio Hasegawa, Toshiaki Yamanaka, Akira Imai, Hiroshi Shiraishi, Takumi Ueno, Hiroshi Fukuda
  • Patent number: 5316496
    Abstract: An electrical connector having multiple pairs of penetrating first apertures (23) and second apertures (24) which are longitudinally formed from bottom (21) to top (22) of insulated connector housing (20), and a cable insertion aperture (25) connects with first aperture (23) and is formed in top (22). Each contact (40) has a beam-shaped contact unit (44) and a holder (46) projecting upward from base (43), and a solder tine (48) extending downward from the base (43). A contact point (45) elastically projects into cable insertion aperture (25). A probe for continuity checking can access contact (40) holder (46) from second aperture (24).
    Type: Grant
    Filed: February 24, 1993
    Date of Patent: May 31, 1994
    Assignee: The Whitaker Corporation
    Inventor: Akira Imai
  • Patent number: 5308728
    Abstract: A dichlorotin phthalocyanine crystal showing, in the X-ray diffractometry using a CuK.sub..alpha. ray, a peak at a Bragg angle (2.theta..+-.0.2.degree.) of 28.2.degree. with any other peak(s) observed at a Bragg angle(s) between 25.degree. and 30.degree. having an intensity of not more than 30% of that of the peak at 28.2.degree.. The crystal is useful as a photoconductive material having sensitivity in the longer wavelength region. The electrophotographic photoreceptor containing the crystal exhibits high sensitivity and excellent durability.
    Type: Grant
    Filed: August 11, 1992
    Date of Patent: May 3, 1994
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Akira Imai, Katsumi Nukada, Katsumi Daimon, Masakazu Iijima, Toru Ishii, Yasuo Sakaguchi, Kiyokazu Mashimo
  • Patent number: 5304446
    Abstract: Disclosed are novel crystals of hydroxyindium phthalocyanine, having distinct diffraction peaks at the particular angles of the Bragg angle (2.theta..+-.0.2) in the X-ray diffraction pattern. An electrophotographic photoreceptor comprising an electroconductive support having thereon a light-sensitive layer containing at least one of an amorphous hydroxyindium phthalocyanine and the above hydroxyindium phthalocyanine crystals. The electrophotographic photoreceptor has excellent sensitivity and durability.
    Type: Grant
    Filed: April 21, 1992
    Date of Patent: April 19, 1994
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Katsumi Daimon, Katsumi Nukada, Akira Imai, Masakazu Iijima, Toru Ishii
  • Patent number: 5302710
    Abstract: A phthalocyanine mixed crystal comprising a halogenated indium phthalocyanine and a halogenated gallium phthalocyanine and an electrophotographic photoreceptor containing the phthalocyanine mixed crystal. The phthalocyanine mixed crystal is a charge generating material which provides an electrophotographic photoreceptor excellent in sensitivity, stability on repeated use, and environmental stability.
    Type: Grant
    Filed: August 11, 1992
    Date of Patent: April 12, 1994
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Katsumi Nukada, Akira Imai, Katsumi Daimon, Masakazu Iijima
  • Patent number: 5302479
    Abstract: Crystals of hydroxygallium phthalocyanine, a method of preparing the crystals, a photoconductive material containing the crystals, and an electrophotographic photoreceptor having the material. The photoreceptor has excellent electrophotographic characteristics. The crystals of hydroxygallium phthalocyanine have distinct diffraction peaks at (i) 7.5.degree., 9.9.degree., 12.5.degree., 16.3.degree., 18.6.degree., 25.1.degree. and 28.3.degree., or (ii) 7.7.degree., 16.5.degree., 25.1.degree. and 26.6.degree., or (iii) 7.9.degree., 16.5.degree., 24.4.degree. and 27.6.degree., or (iv) 7.0.degree., 7.5.degree., 10.5.degree., 11.7.degree., 12.7.degree., 17.3.degree., 8.1.degree., 24.5.degree., 26.2.degree. and 27.1.degree., or (v) 6.8.degree., 12.8.degree., 15.8.degree. and 26.0.degree. or (vi) 7.4.degree., 9.9.degree., 25.0.degree., 26.0.degree., and 28.2.degree. of the Bragg angle (2.theta..+-.0.2) in the X-ray diffraction spectrum.
    Type: Grant
    Filed: April 24, 1992
    Date of Patent: April 12, 1994
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Katsumi Daimon, Katsumi Nukada, Akira Imai, Masakazu Iijima, Kazuo Yamasaki, Kiyokazu Mashimo, Yasuo Sakaguchi, Toru Ishii
  • Patent number: 5292604
    Abstract: A phthalocyanine crystal of mixed pigments of oxytitanium phthalocyanine and a halogenated gallium phthalocyanine or a halogenated indium phthalocyanine is disclosed. The phthalocyanine crystal of mixed pigments is used as a charge generating material which provides an electrophotographic photoreceptor excellent in sensitivity, stability on repeated use, and environmental stability.
    Type: Grant
    Filed: June 16, 1992
    Date of Patent: March 8, 1994
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Katsumi Nukada, Akira Imai, Katsumi Daimon, Masakazu Iijima