Patents by Inventor Masataka Yamashita

Masataka Yamashita 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: 5183586
    Abstract: A ferroelectric chiral smectic liquid crystal composition, comprising at least one compound represented by the following formula (I): ##STR1## wherein R.sub.1 denotes a linear or branched alkyl group having 1-18 carbon atoms capable of having a substituent, R.sub.2 denotes a linear or branched alkyl group having 1-14 carbon atoms capable of having a substituent; X.sub.1 and X.sub.2 respectively denote a single bond, --O--, ##STR2## m is 0-7; and n is 0 or 1; and at least one compound represented by the following formula (II): ##STR3## wherein R.sub.3 and R.sub.4 respectively denote a linear or branched alkyl group having 1-18 carbon atoms capable of having a substituent; X.sub.3 and X.sub.4 respectively denote a single bond, --O--, ##STR4## Y.sub.1 denotes --CH.sub.2 O-- or --OCH.sub.2 --; and p and q are respectively 1 or 2.
    Type: Grant
    Filed: July 12, 1989
    Date of Patent: February 2, 1993
    Assignee: Canon Kabushiki Kaisha
    Inventors: Masahiro Terada, Takeshi Togano, Masataka Yamashita, Takashi Iwaki, Shosei Mori, Kenji Shinjo
  • Patent number: 5173211
    Abstract: A ferroelectric chiral smectic liquid crystal composition, comprising at least one optically active compound represented by the following formula (I): ##STR1## wherein R.sub.1 denotes a linear or branched alkyl group having 1-18 carbon atoms capable of having a substituent; R.sub.2 denotes a linear or branched alkyl group having 1-14 carbon atoms capable of having a substituent; and X.sub.1 denotes a single bond, ##STR2## and at least one optically active compound represented by the following formula (II): ##STR3## wherein R.sub.3 denotes a linear alkyl group having 1-14 carbon atoms; R.sub.4 denotes a linear or branched alkyl group having 1-14 carbon atoms capable of having a substituent; and X.sub.
    Type: Grant
    Filed: July 12, 1989
    Date of Patent: December 22, 1992
    Assignee: Canon Kabushiki Kaisha
    Inventors: Masataka Yamashita, Takeshi Togano, Masahiro Terada, Akio Yoshida, Yoshiko Kimura, Kenji Shinjo, Hiroyuki Kitayama, Shinichi Nakamura
  • Patent number: 5165076
    Abstract: A ferroelectric liquid crystal device comprises a pair of opposite electrodes and a ferroelectric liquid crystal disposed between the electrodes. At least one of the opposite electrodes is coated with a primer layer and an alignment layer on the primer layer. The alignment layer has a thickness d.sub.2 and is made of a material having a dielectric constant .epsilon..sub.2, and the primer layer has a thickness d.sub.1 and is made of a material having a dielectric constant .epsilon..sub.1 which are greater than d.sub.2 and .epsilon..sub.2, respectively. The ferroelectric liquid crystal is at least one mesomorphic compound represented by the formula R.sub.1 --A.sub.1 --X--A.sub.2 --R.sub.2 wherein A.sub.1 and A.sub.2 respectively denote a 6-membered ring-containing divalent group; X denotes a single bond or a divalent chain group; and R.sub.1 and R.sub.2 respectively denote a branch or linear chain group, R.sub.1 and R.sub.2 being the same or different.
    Type: Grant
    Filed: October 2, 1989
    Date of Patent: November 17, 1992
    Assignee: Canon Kabushiki Kaisha
    Inventors: Akira Tsuboyama, Yutaka Inaba, Akio Yoshida, Yukio Hanyu, Toshiharu Uchimi, Masataka Yamashita
  • Patent number: 5143643
    Abstract: An optically active mesomorphic compound represented by the formula (III) is obtained through an optically active compound represented by the formula (I) and then through a compound represented by the formula (II), respectively, shown below. ##STR1## In the above formulas, R represents a linear, branched or cyclic saturated or unsaturated hydrocarbon group having 1-18 carbon atoms each capable of having a substituent, C* represents an asymmetric carbon atom, k is an integer of from 2 to 5, A is a releasable active group such as hydroxyl, l is 0 or 1, and when l is 1, m is 0, 1 or 2 and n is 0 or 1; R.sup.1 represents an alkyl or alkoxy group having 1-18 carbon atoms; ##STR2## respectively denote ##STR3## p, q and r are respectively 0 or 1 satisfying the relation of p+q+r.gtoreq.1.
    Type: Grant
    Filed: July 3, 1989
    Date of Patent: September 1, 1992
    Assignee: Canon Kabushiki Kaisha
    Inventors: Takashi Iwaki, Kenji Shinjo, Akio Yoshida, Masataka Yamashita, Kazuharu Katagiri, Chieko Hioki, Takeshi Togano, Yoko Yamada, Masahiro Terada
  • Patent number: 5139697
    Abstract: A liquid crystal composition comprises at least one compound represented by the formula [I] below and at least one compound represented by the formula [II] below: ##STR1## wherein R.sub.1 denotes an alkyl group having 1-16 carbon atoms capable of having a substituent; R.sub.2 denotes any one of alkyl group, alkoxy group, alkoxycarbonyl group, acyloxy group and alkoxycarbonyloxy group, each having 1-16 carbon atoms and being capable of having a substituent; and A denotes any one of ##STR2## each capable of having a substituent; and ##STR3## wherein R.sub.3 denotes a linear alkyl group having 1-16 carbon atoms; R.sub.4 denotes a linear alkyl group having 1-12 carbon atoms; X.sub.1 is a single bond, --O--, ##STR4## X.sub.2 is --OCH.sub.2 --, ##STR5## or --CH.sub.
    Type: Grant
    Filed: May 30, 1991
    Date of Patent: August 18, 1992
    Assignee: Canon Kabushiki Kaisha
    Inventors: Takeshi Togano, Masahiro Terada, Masataka Yamashita, Shosei Mori, Takashi Iwaki
  • Patent number: 5119219
    Abstract: A liquid crystal apparatus includes a chiral smectic liquid crystal showing a first and a second orientation state disposed between first and second electrodes of a liquid cell. A drive circuit applies voltages between the first and second electrodes including voltages .vertline.V.sub.S .vertline. and .vertline.V.sub.I .vertline. which provide voltages V.sub.A and V.sub.B (V.sub.B V.sub.A) satisfying the relationship of: .vertline.(V.sub.A -V.sub.B)/(V.sub.A +V.sub.B).vertline.>0.1 at 40.degree. C. V.sub.A is a minimum peak value of a voltage .vertline.V.sub.S .vertline.+.vertline.V.sub.I .vertline. (at a constant pulse width) capable of inverting the first orientation state of the chiral smectic liquid crystal into the second orientation state when a voltage pulse is applied between the first and second electrodes to cause the first orientation state of the chiral smectic liquid crystal and then the voltage .vertline.V.sub.S .vertline.+.vertline.V.sub.I .vertline.
    Type: Grant
    Filed: June 26, 1990
    Date of Patent: June 2, 1992
    Assignee: Canon Kabushiki Kaisha
    Inventors: Masahiro Terada, Masataka Yamashita, Shosei Mori, Shinichi Nakamura, Kenji Shinjo, Kazuharu Katagiri
  • Patent number: 5099344
    Abstract: A ferroelectric liquid crystal device comprises a pair of opposite electrodes and a ferroelectric liquid crystal disposed between the electrodes. At least one of the opposite electrodes is coated with an insulating film having a thickness of 200 .ANG. or larger. The ferroelectric liquid crystal has a capacitance C.sub.LC measured in (nF/cm.sup.2) and a spontaneous polarization PS measured in (nC/cm.sup.2) and the insulating film has a capacitance Ci measured in (nF/cm.sup.2) wherein the magnitudes of C.sub.LC, Ps, and Ci satisfy the relationship ofCi.gtoreq.7.multidot.Ps-C.sub.LC.
    Type: Grant
    Filed: May 16, 1991
    Date of Patent: March 24, 1992
    Assignee: Canon Kabushiki Kaisha
    Inventors: Akira Tsuboyama, Yutaka Inaba, Akio Yoshida, Yukio Hanyu, Toshiharu Uchimi, Masataka Yamashita
  • Patent number: 4883344
    Abstract: A liquid crystal device comprises a pair of parallel substrates and a ferroelectric liquid crystal disposed between the substrates so as to have an arrangement of molecules forming a plurality of layers perpendicular to the faces of the substrates. At least one of the pair of substrates has an alignment control film formed of a modified polyvinyl alcohol resin having a function of aligning said plurality of layers preferentially in one direction. The modified polyvinyl alcohol resin film stably provides a uniform alignment state with a large tilt angle than a conventional alignment control film of polyimide or unmodified polyvinyl alcohol.
    Type: Grant
    Filed: January 24, 1989
    Date of Patent: November 28, 1989
    Assignee: Canon Kabushiki Kaisha
    Inventors: Shinjiro Okada, Kazuo Yoshinaga, Osamu Taniguchi, Hideyuki Kawagishi, Akira Tsuboyama, Yukio Hanyu, Masataka Yamashita, Kazuharu Katagiri
  • Patent number: 4820026
    Abstract: A liquid crystal device comprises a pair of parallel substrates and a ferroelectric liquid crystal disposed between the substrates so as to have an arrangement of molecules forming a plurality of layers perpendicular to the faces of the substrates. At least one of the pair of substrates has an alignment control film formed of a modified polyvinyl alcohol resin having a function of aligning said plurality of layers preferentially in one direction. The modified polyvinyl alcohol resin film stably provides a uniform alignment state with a larger tilt angle than a conventional alignment control film of polyimide or unmodified polyvinyl alcohol.
    Type: Grant
    Filed: March 17, 1987
    Date of Patent: April 11, 1989
    Assignee: Canon Kabushiki Kaisha
    Inventors: Shinjiro Okada, Kazuo Yoshinaga, Osamu Taniguchi, Hideyuki Kawagishi, Akira Tsuboyama, Yukio Hanyu, Masataka Yamashita, Kazuharu Katagiri
  • Patent number: 4788119
    Abstract: The invention provides an electrophotographic photosensitive member having an improved sensitivity and an improved potential stability when repeatedly copied by using a photosensitive layer containing a disazo pigment having a specific molecular structure.
    Type: Grant
    Filed: May 27, 1986
    Date of Patent: November 29, 1988
    Assignee: Canon Kabushiki Kaisha
    Inventors: Masataka Yamashita, Hajime Miyazaki, Takao Takiguchi, Masakazu Matsumoto, Masaaki Hiro, Shozo Ishikawa
  • Patent number: 4760003
    Abstract: An electrophotographic photosensitive member comprises a photosensitive layer on a substrate, said photosensitive layer comprising a disazo pigment represented by the formula (1).
    Type: Grant
    Filed: May 21, 1986
    Date of Patent: July 26, 1988
    Assignee: Canon Kabushiki Kaisha
    Inventors: Masakazu Matsumoto, Takao Takiguchi, Masataka Yamashita, Shoji Umehara, Shozo Ishikawa, Hajime Miyazaki
  • Patent number: 4743523
    Abstract: A photosensitive member for electrophotography comprising a photosensitive layer containing an azo pigment selected from those represented by the following formulas (1)-(6): ##STR1## wherein R is an alkyl, aralkyl, aryl, or acyl each capable of having a substituent; Ar is an arylene or heterocyclic group each capable of having a substituent; Ar is a coupler residue group having a phenolic OH group; B is hydrogen, nitroso, or an alkyl, aralkyl, aryl or acyl group capable of having a substituent; and n is 0 or 1.
    Type: Grant
    Filed: March 27, 1986
    Date of Patent: May 10, 1988
    Assignee: Canon Kabushiki Kaisha
    Inventors: Masataka Yamashita, Takao Takiguchi, Shoji Umehara, Masakazu Matsumoto, Shozo Ishikawa
  • Patent number: 4735882
    Abstract: An electrophotographic photosensitive member comprises a photosensitive layer containing an azo pigment selected from the following general formulae (1) to (5): ##STR1## wherein groups Ar are arylene groups and divalent heterocyclic groups, each of which may contain a substituent; n is 0 or 1; and group A is a coupler residue group having a phenolic OH group.
    Type: Grant
    Filed: April 1, 1986
    Date of Patent: April 5, 1988
    Assignee: Canon Kabushiki Kaisha
    Inventors: Masataka Yamashita, Takao Takiguchi, Shoji Umehara, Masakazu Matsumoto, Shozo Ishikawa
  • Patent number: 4717636
    Abstract: An electrophotographic photosensitive member comprises at least a charge generation layer and a charge transport layer on an electroconductive substrate, wherein said charge generation layer contains, as a binder, a polyvinylacetal resin obtained by acetalization reaction of polyvinyl alcohol and aldehyde compound represented by the following general formula:Ar-CHOwherein Ar stands for a substituted or unsubstituted aryl radical.
    Type: Grant
    Filed: April 17, 1986
    Date of Patent: January 5, 1988
    Assignee: Canon Kabushiki Kaisha
    Inventors: Hideyuki Takahashi, Masataka Yamashita, Masakazu Matsumoto, Minoru Mabuchi
  • Patent number: 4702982
    Abstract: This invention relates to an electrophotographic photosensitive member utilizing a novel electrophotographic photosensitive material, more particularly to an electrophotographic photosensitive member endowed with high sensitivity as well as excellent potential stability during repeated copying by incorporating an azo pigment having a specific molecular structure in the photosensitive layer.
    Type: Grant
    Filed: May 22, 1986
    Date of Patent: October 27, 1987
    Assignee: Canon Kabushiki Kaisha
    Inventors: Masakazu Matsumoto, Takao Takiguchi, Masataka Yamashita, Shoji Umehara, Shozo Ishikawa
  • Patent number: 4666810
    Abstract: An electrophotographic photosensitive member comprises a photosensitive layer containing an azo pigment selected from the general formulae (1) to (6).
    Type: Grant
    Filed: April 15, 1986
    Date of Patent: May 19, 1987
    Assignee: Canon Kabushiki Kaisha
    Inventors: Shoji Umehara, Masakazu Matsumoto, Takao Takiguchi, Masataka Yamashita, Shozo Ishikawa
  • Patent number: 4666809
    Abstract: An electrophotographic photosensitive member having a conductive substrate and a photosensitive layer, which is characterized in that the photosensitive layer comprises a binder and at least one hydrazone compound represented by the following general formula (1) or (2): ##STR1## In the formula; R.sub.11 and R.sub.12 independently of each other represent alkyl, aralkyl, or phenyl, each substituted or unsubstituted, or R.sub.11 and R.sub.12 form a 5- or 6-membered ring residue conjointly with the nitrogen atom to which they are bonded; R.sub.13 and R.sub.14 independently of each other represent alkyl or alkoxy; R.sub.15 and R.sub.16 independently of each other represent alkyl, aralkyl, or aryl, wherein the aralkyl and the aryl are substituted or unsubstituted; and n represents a integer of 0 or 1. ##STR2## In the formula; R.sub.21 and R.sub.22 independently of each other represent alkyl, aralkyl, or phenyl, each substituted or unsubstituted, or R.sub.21 and R.sub.
    Type: Grant
    Filed: July 1, 1985
    Date of Patent: May 19, 1987
    Assignee: Canon Kabushiki Kaisha
    Inventors: Masakazu Matsumoto, Masataka Yamashita
  • Patent number: 4571369
    Abstract: Photoconductive film having a photoconductive pigment obtained by silylation of pigment having at least one hydroxy group, and electrophotographic photosensitive member making use thereof.
    Type: Grant
    Filed: April 13, 1984
    Date of Patent: February 18, 1986
    Assignee: Canon Kabushiki Kaisha
    Inventor: Masataka Yamashita