Patents by Inventor Yukari Sakai

Yukari Sakai 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: 6245257
    Abstract: The liquid crystal composition of the invention contains at least two compounds represented by the following formula (A) and each having different structures, one or more methylene group in the alkylene group R1 may be substituted with —O— groups, not less than 50% by weight, and has a transmitted light quantity I32 satisfying the condition of 0.5≦I32≦0.50, wherein R1 is an alkyl group of 2 to 20 carbon atoms; m is 0 or 1; Z is a —COO— group or a —CH2O— group; X is a hydrogen atom, a methyl group or a trifluoromethyl group; and R2 is a group selected from the group consisting of a straight-chain alkyl group of 1 to 5 carbon atoms, an ether group represented by —(CH2)p—O—(CH2)qCH3 and an alkene group wherein a terminal ethyl group consisting a straight-chain alkyl group of 2 to 5 carbon atoms is replaced with a group having a C═C double bond.
    Type: Grant
    Filed: August 10, 1998
    Date of Patent: June 12, 2001
    Assignee: Mitsui Chemicals INC
    Inventors: Yukari Sakai, Shinichi Nishiyama, Toyotaro Maruyama, Takahiro Fujiyama
  • Patent number: 6117359
    Abstract: The invention to provide novel tetralin compounds, liquid crystal materials and liquid crystal compositions, which can constitute a liquid crystal element affording a wide operating temperature range, a high switching speed and a small consumption of electric power as well as a stable contrast.The tetralin compound of the invention is represented by the following formula [I] ##STR1## wherein R.sup.1 is an alkyl group or a polyfluoroalkyl group of 3-20 carbon atoms (wherein one --CH.sub.2 -- or 2 or more --CH.sub.2 -- or --CF.sub.2 -- not adjacent to each other in these groups may be substituted with --O--), X is --COO--, --O-- or a single bond, A is each independently selected from ##STR2## (Z.sup.1 and Z.sup.2 are hydrogen or fluorine), Y is a group selected from --COO--, --CH.sub.2 O--, --OCH.sub.2 --, and --CH.sub.2 CH.sub.2 --, R.sup.1 * is an optically active group represented by the formula --C*H--(CF.sub.3)--(CH.sub.2).sub.m --O--C.sub.n H.sub.2n+1 [II].
    Type: Grant
    Filed: September 21, 1999
    Date of Patent: September 12, 2000
    Assignee: Mitsui Chemicals Inc
    Inventors: Takahiro Fujiyama, Toyotaro Maruyama, Yukari Sakai
  • Patent number: 5922242
    Abstract: An LCD which having a high response speed, a wide viewing angle and a high contrast and capable of displaying high-quality gray-scale images at normal temperature. The LCD comprises an array substrate, a counter substrate opposing the array substrate, pixel electrodes arranged on the the array substrate in rows and columns, each connected to an active element, a first orientation film provided on the pixel electrodes, a counter electrode opposing the pixel electrodes, arranged on the counter substrate, a second orientation film provided on the counter electrode, rubbed in a direction slightly inclined to a direction in which the first orientation has been rubbed, and a layer of antiferroelectric liquid crystal sealed in a gap between the first and second orientation films, the antiferroelectric liquid crystal being a smectic liquid crystal which contains an antiferroelectric liquid crystal compound represented by R.sup.1 (O)--Zm--Y--E--COO--C*HX--R.sup.4.
    Type: Grant
    Filed: May 19, 1997
    Date of Patent: July 13, 1999
    Assignees: Kabushiki Kaisha Toshiba, Mitsui Chemicals, Inc.
    Inventors: Tatsuo Saishu, Kohki Takatoh, Hideo Hama, Yukari Sakai
  • Patent number: 5888420
    Abstract: Disclosed is a liquid crystal device comprising a liquid crystal cell filled with a liquid crystal material capable of exhibiting a smectic phase, said cell including upper and lower substrates each having in order an electrode and an orientation film in contact with the liquid crystal material, a cross angle e formed by the orientation treatment directions of the orientation films is 180.degree.-.delta. or 360.degree.-.delta. (0.degree.<.delta..ltoreq.90.degree.). Also disclosed is a process for preparing the above-mentioned liquid crystal device comprising treating the orientation films and preparing the liquid crystal cell so as to have the orientation treatment directions of the orientation films form the cross angle .THETA. within the above range in the cell.
    Type: Grant
    Filed: December 20, 1996
    Date of Patent: March 30, 1999
    Assignee: Mitsui Chemicals, Inc.
    Inventors: Yukari Sakai, Mitsuko Nagai, Hideo Hama
  • Patent number: 5724115
    Abstract: Disclosed is a liquid crystal device comprising a liquid crystal cell filled with a liquid crystal material capable of exhibiting a smectic phase, said cell including upper and lower substrates each having in order an electrode and an orientation film in contact with the liquid crystal material, a cross angle .THETA. formed by the orientation treatment directions of the orientation films is 180.degree.-.delta. or 360.degree.-.delta. (0.degree.<.delta..ltoreq.90.degree.). Also disclosed is a process for preparing the above-mentioned liquid crystal device comprising treating the orientation films and preparing the liquid crystal cell so as to have the orientation treatment directions of the orientation films form the cross angle .THETA. within the above range in the cell.
    Type: Grant
    Filed: June 2, 1995
    Date of Patent: March 3, 1998
    Assignee: Mitsui Petrochemical Industries, Ltd.
    Inventors: Yukari Sakai, Mitsuko Nagai, Hideo Hama
  • Patent number: 5719653
    Abstract: Striped electrodes are formed on upper and lower substrates respectively, and a plurality of partition members are formed in a striped fashion so that a plurality of parallel sealed linear interstices R, each having a rectangular section, are formed between the substrates. A upper-side rubbing direction crosses a lower-side rubbing direction at a predetermined angle, and the direction of extension of each of the partition members is caused to fall within the above cross angle. An antiferroelectric liquid crystal is sealed in the linear interstices, and the liquid crystal panel is cooled while proceeding from one end of the linear interstices to the other end thereof. The layer normal direction of liquid crystal molecular layer becoming irregular between the upper and lower substrates is prevented by the employment of the cross rubbing method to thereby avoid the occurrence of defects in the liquid crystal.
    Type: Grant
    Filed: January 24, 1996
    Date of Patent: February 17, 1998
    Assignees: Toppan Printing Co., Ltd., Mitsui Petrochemical Industries, Ltd.
    Inventors: Takao Minato, Katsuhiro Suzuki, Hideo Hama, Yukari Sakai
  • Patent number: 5589966
    Abstract: The liquid crystal light modulation device of the present invention comprising a liquid crystal element consisting of one of plural liquid crystal cells and a voltage signal input means electrically connected with the liquid crystal element, wherein each liquid crystal cell contains a chiral smectic liquid crystal material layer and when a voltage signal is input to the liquid crystal element, the polarization direction of a light transmitted by the liquid crystal element is changed by approx. 90.degree. as compared with the state where the voltage signal is not input to the liquid crystal element enables a change of a light path and an open-close (on-off) operation of a light path at a high speed (optical switching time: not longer than 1 msec).
    Type: Grant
    Filed: May 3, 1994
    Date of Patent: December 31, 1996
    Assignee: Mitsui Petrochemical Industries, Ltd.
    Inventors: Hideo Hama, Yukari Sakai