Rewritable bar code display medium, and image display method and image display apparatus using the same

• US 5,298,476 A
• Filed: 07/05/1991
• Issued: 03/29/1994
• Est. Priority Date: 07/06/1990
• Status: Expired due to Term

• Current Assignee: Ricoh Company Limited
• Original Assignee: Ricoh Company Limited
• Inventors: Yano, Takashi, Hotta, Yoshihiko, Maruyama, Shoji, Takayama, Hajime, Kubo, Keishi
• Primary Examiner(s): HESS, BRUCE H
• Application Number:
  US07/726,210
• Time in Patent Office: 998 Days
• Field of Search: 428/195, 428/913, 503/201, 503/208, 503/209, 503/214, 503/217, 503/225, 503/226
• US Class Current: 503/227
• CPC Class Codes: B41M 5/363 using materials comprising a polymeric matrix containing a low molecular weight organic compound such as a fatty acid, e.g. for reversible recording
• CPC Class Codes: G02F 1/0147 based on thermo-optic effects G02F1/132 takes precedence
• CPC Class Codes: G06K 1/126 by photographic or thermographic registration recording apparatus for measuring instruments G01D15/00
• CPC Class Codes: G06K 17/00 Methods or arrangements for effecting co-operative working between equipments covered by two or more of main groups G06K1/00 - G06K15/00, e.g. automatic card files incorporating conveying and reading operations
• CPC Class Codes: G06K 19/06028 using bar codes
• CPC Class Codes: G06K 2019/06281 rewritable
• CPC Class Codes: Y10S 235/90 Means to affix bar code, e.g. attaching, etching, coating, printing
• CPC Class Codes: Y10S 428/913 Material designed to be responsive to temperature, light, moisture

Abstract

A rewritable bar code display medium is disclosed, which is composed of a support and a reversible thermosensitive recording layer for reversibly forming bar codes therein formed on the support, which reversible thermosensitive recording layer varies in transparency with change in temperature, and an image display method using the rewritable bar code display medium, and an apparatus for implementing the image display method are also disclosed.

Claims

1. A rewritable bar code display medium comprising a support and a reversible thermosensitive recording layer for reversibly forming bar codes therein formed on said support, which reversible thermosensitive recording layer varies in transparency with change in temperature.

2. The rewritable bar code display medium as claimed in claim 1, wherein said reversible thermosensitive recording layer comprises a resin matrix and a low-molecular weight organic compound dispersed in said resin matrix.

3. The rewritable bar code display medium as claimed in claim 2, wherein said low-molecular weight organic compound has an average particle diameter which is equal to 1/8 to 2 times the wavelength of a light beam for reading said bar codes.

4. The rewritable bar code display medium as claimed in claim 2, wherein said low-molecular weight organic compound has an average particle diameter in the range of 0.1 μ

m to 2.0 μ

m.

5. The rewritable bar code display medium as claimed in claim 1, wherein the width of the temperature range in which said reversible thermosensitive recording layer is transparent is 15 to 80 degrees C.

6. The rewritable bar code display medium as claimed in claim 1, further comprising a light reflection layer which is interposed between said support and said reversible thermosensitive recording layer.

7. The rewritable bar code display medium as claimed in claim 1, further comprising a pigment layer which is interposed between said support and said reversible thermosensitive recording layer.

8. The rewritable bar code display medium as claimed in claim 1, further comprising a light reflection layer which is provided on the back side of said support opposite to said reversible thermosensitive recording layer.

9. The rewritable bar code display medium as claimed in claim 1, further comprising a pigment layer which is provided on the back side of said support opposite to said reversible thermosensitive recording layer.

10. An image display method of forming an image in a white opaque state or in a transparent state comprising the step of applying heat to a rewritable bar code display medium comprising a support and a reversible thermosensitive recording layer formed thereon which is reversibly altered between a transparent state and a white opaque state with change in temperature and which comprises a resin matrix and a low-molecular weight organic compound dispersed in said resin matrix.

11. The image display method as claimed in claim 10, wherein said image is read by application of a light beam with a wavelength in the range of 1/8 to 2 times the average particle diameter of said low-molecular weight organic compound to said reversible thermosensitive recording layer.