Liquid crystal display cell

• US 3,973,388 A
• Filed: 03/12/1975
• Issued: 08/10/1976
• Est. Priority Date: 03/18/1974
• Status: Expired due to Term

• Current Assignee: Citizen Watch Co Limited (Citizen Electronics Company Limited)
• Original Assignee: Citizen Watch Co Limited (Citizen Electronics Company Limited)
• Inventors: Yoshida, Masateru, Natori, Minoru
• Primary Examiner(s): McCamish, Marion E.
• Assistant Examiner(s): Dixon, Jr., William R.
• Application Number:
  US05/557,613
• Time in Patent Office: 517 Days
• Field of Search: 428/1, 428/213, 428/215, 428/337, 428/913, 350/160 LC, 240/6.43, 58/50 R
• US Class Current: 368/242
• CPC Class Codes: G02F 1/133308 Support structures for LCD panels, e.g. frames or bezels
• CPC Class Codes: G02F 1/133368 Cells having two substrates with different characteristics, e.g. different thickness or material
• CPC Class Codes: G02F 2201/503 Arrangements improving the resistance to shock
• CPC Class Codes: G04G 17/06 Electric connectors, e.g. conductive elastomers
• CPC Class Codes: G04G 9/0035 constructional
• CPC Class Codes: Y10S 428/913 Material designed to be responsive to temperature, light, moisture
• CPC Class Codes: Y10T 428/24967 Absolute thicknesses specified
• CPC Class Codes: Y10T 428/266 of base or substrate

Abstract

A liquid crystal, electrochromic or other electro-optical material is sandwiched between two glass substrates. An electric field is applied to the electro-optical material to display time and other information on a watch. The lower glass substrate is thinner than the upper substrate so as to create clear displays and to enable the manufacture of a thin watch which is also light weight and shock resistant.

Claims

1. An electro-optical watch display cell having an electro-optic material selected from the group consisting of the liquid crystal, electrochromic, and other electro-optical types, said cell having an upper glass substrate and a lower glass substrate, said upper and lower glass substrates sandwiching said electro-optical material thereinbetween, said glass substrates arranged and configured such that said upper substrate supports said electro-optical display cell in said watch, and wherein said lower glass substrate is sufficiently thin so as to substantially reduce the formation of undesired shadow images.

2. The electro-optical watch display cell according to claim 1 wherein said display cell is arranged in the shape of a numeral.

3. The electro-optical watch display cell according to claim 1 wherein said display cell is arranged in the shape of a letter.

4. The electro-optical display cel according to claim 1, wherein the thickness of said lower glass substrate is less than 0.4 mm.

5. The electro-optical display cell according to claim 1, wherein, in addition thereto, first and second polarization plates are disposed in said display cell, said first polarization plate disposed above said upper glass substrate and said second polarization plate disposed beneath said lower glass substrate.

6. In a watch, an electro-optical display cell arranged to visually indicate predetermined information, said display cell having a reflector, a bottom polarization plate disposed on said reflector, a lower glass substrate disposed on said polarization plate, a liquid crystal layer disposed on said lower glass substrate, an upper glass substrate disposed on said liquid crystal layer, and a top polarization plate disposed on said upper glass substrate;

wherein the improvement comprises said upper glass substrate coupled to said watch and having a thickness sufficient to support the entire display cell and said lower glass substrate being sufficiently thin so as to substantially reduce the formation of undesired shadow images.

7. The electro-optical display cell according to claim 6 wherein said lower glass substrate has a thickness less than 0.4 mm.

8. The electro-optical display cell according to claim 6 wherein said lower glass substrate has a thickness of about 0.3 mm -0.2 mm.