Polymer dispersed liquid crystal information recording medium with information recording layer comprising acrylic or methacrylic resin having molecular weight of 25,000 to 100,000 and information recording and reproducing method

• US 5,583,670 A
• Filed: 09/10/1993
• Issued: 12/10/1996
• Est. Priority Date: 01/10/1992
• Status: Expired due to Term

• Current Assignee: Dai Nippon Printing Company Limited
• Original Assignee: Dai Nippon Printing Company Limited
• Inventors: Iijima, Masayuki, Nakayasu, Yuichi
• Primary Examiner(s): Gross, Anita Pellman
• Assistant Examiner(s): TON, MINH TOAN T
• Application Number:
  US08/117,054
• Time in Patent Office: 1,187 Days
• Field of Search: 359/51, 359/72, 359/52, 359/103
• US Class Current: 349/86
• CPC Class Codes: C09K 19/544 as dispersing or encapsulating medium around the liquid crystal
• CPC Class Codes: G02F 1/1334 based on polymer dispersed liquid crystals, e.g. microencapsulated liquid crystals
• CPC Class Codes: G02F 1/135 Liquid crystal cells structurally associated with a photoconducting or a ferro-electric layer, the properties of which can be optically or electrically varied G02F1/133348 takes precedence
• CPC Class Codes: G11B 7/24 Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the arrangement of information on the carrier G11B7/007
• CPC Class Codes: G11C 13/047 using electro-optical elements G11C13/042 takes precedence

Abstract

The information recording medium of the present invention comprises an information recording layer made of acrylic resin or metacrylic resin 11 being laminated on an electrode layer 13, a liquid crystal phase 12 being dispersed and fixed on said information recording layer, whereby said acrylic resin or metacrylic resin has weight average molecular weight of 10,000 to 100,000, electrostatic information can be permanently recorded and stored as visible information, and the visible information can be reproduced at any desired time. Further, the visible information can be easily erased by heating, and medium can be re-used.

Claims

1. An information recording medium, comprising an information recording layer of acrylic resin or methacrylic resin being laminated on an electrode layer, a liquid crystal phase that is a nematic phase or a cholesteric phase at operating environmental temperature being dispersed and fixed on said information recording layer, whereby weight average molecular weight of said acrylic resin or methacrylic resin is 25,000 to 100,000.

4. An information recording medium according to one of claims 1 to 3, wherein said information recording layer is heated, before recording of information, at a temperature higher than room temperature and lower than the temperature at which liquid crystal transits to isotropic phase.

5. An information recording medium according to one of claims 1 to 3, wherein said resin has glass transition temperature higher than operating environmental temperature.

6. An information recording medium according to one of claims 1 to 3, wherein said information recording layer is laminated on the electrode layer via a charge blocking layer.

2. An information recording medium, comprising an information recording layer of acrylic resin or methacrylic resin being laminated on an electrode layer, a liquid crystal phase that is a nematic phase or a cholesteric phase at operating environmental temperature being dispersed and fixed on said information recording layer, whereby weight average molecular weight of said acrylic resin or methacrylic resin is 25,000 to 100,000 and has an acid number of 2 or more.

3. An information recording medium, comprising an information recording layer of acrylic resin or methacrylic resin and an electric charge retaining layer that are sequentially laminated on an electrode layer, a liquid crystal phase that is a nematic phase or a cholesteric phase at operating environmental temperature being dispersed and fixed on said information recording layer, whereby weigh average molecular weight of said acrylic resin or methacrylic resin is 25,000 to 100,000.

7. An electrostatic information recording and reproducing method, characterized in that an information recording medium is placed face-to-face to a photosensitive member comprising a photoconductive layer formed on an electrode layer, said information recording medium comprising an information recording layer of acrylic resin or methacrylic resin being laminated on an electrode layer, a liquid crystal phase that is a nematic phase or a cholesteric phase at operating environmental temperature being dispersed and fixed on said information recording layer, said resin having weight average molecular weight of 25,000 to 100,000, electrostatic information recording is performed by exposing to light from the direction of the photosensitive member of the information recording medium while applying a voltage between said two electrodes, and electrostatic information is recorded and stored as visible information and is reproduced at any time desired.

8. An electrostatic information recording and reproducing method, characterized in that an information recording medium is placed face-to-face to a photosensitive member comprising a photoconductive layer on an electrode layer, said information recording medium comprising an information recording layer made of acrylic resin or methacrylic resin being laminated on an electrode layer, a liquid crystal phase that is a nematic phase or a cholesteric phase at operating environmental temperature being dispersed and fixed on said information recording layer, said resin having weight average molecular weight of 25,000 to 100,000 and an acid number of 2 or more, electrostatic information recording is performed by exposing to light from the direction of the photosensitive member or the information recording medium while applying a voltage between two electrodes, and electrstatic information is recorded and stored as visible information and reproduced at any time desired.

9. An electrostatic information recording and reproducing method according to claim 8, wherein visible information is reproduced by transmitted light or reflected light.