Liquid crystal display device

• US 4,519,679 A
• Filed: 09/08/1982
• Issued: 05/28/1985
• Est. Priority Date: 02/03/1981
• Status: Expired due to Term

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Ideno, Hiroaki, Ueda, Fumio, Horikiri, Kenji
• Primary Examiner(s): Corbin, John K.
• Assistant Examiner(s): NOT, DEFINED
• Application Number:
  US06/422,978
• Time in Patent Office: 993 Days
• Field of Search: 350/339 F, 350/339 R, 350/345
• US Class Current: 349/106
• CPC Class Codes: G02F 1/133374 for displaying permanent signs or marks
• CPC Class Codes: G02F 1/1335 Structural association of cells with optical devices, e.g. polarisers or reflectors
• CPC Class Codes: G02F 1/133555 Transflectors
• CPC Class Codes: G09F 9/00 Indicating arrangements for variable information in which the information is built-up on a support by selection or combination of individual elements in which the variable information is permanently attached to a movable support G09F11/00; abacus G06C1/00; slide-rules G06G1/00
• CPC Class Codes: G09F 9/35 being liquid crystals G09F9/302 takes precedence; liquid crystal materials C09K19/00; liquid crystal panels comprising a number of electrodes in a single cell per se G02F1/13

Abstract

A liquid crystal display device which has a good legibility and is easily produced has a first and a second polarizer with a TN type liquid crystal display element therebetween, the optical axes of the two polarizers being parallel to each other. A color filter is arranged to be in contact with either one of those polarizers and a transflector is arranged so as to be in contact with the color filter, the arrangement being such that the illumination of light is effected through the transflector.

Claims

1. A liquid crystal display device comprising:

a TN type liquid crystal display element having a plurality of liquid crystal display patterns formed thereon;

a front panel having semi-transparent ink portions aiding the recognition of display contents and a plurality of transparent portions identical in shape to said liquid crystal display patterns on a surface of a transparent substrate respectively, said front panel being provided on the remaining portions with a light shielding print;

a first polarizer and a second polarizer which are arranged such that said display element is between and in contact with said polarizers and which have their optical axes parallel to each other, said first polarizer being formed of a plurality of polarizing plates identical in shape to and somewhat larger in size than said liquid crystal display patterns respectively and disposed on one side of said display elements, said polarizing plates being identical to or somewhat larger in size than said transparent portions on said front panel, said second polarizer being disposed on the entire area of another side of said display element;

a color filter disposed in contact with said second polarizer, said color filter including a plurality of color filter portions identical in shape to said liquid crystal display patterns respectively;

a transflector disposed in contact with said color filter; and

a light source disposed to effect the illumination through said transflector.

2. A liquid crystal display device as claimed in claim 1, wherein said color filter comprises a transparent film having a polychromic transparent coating material thereon and arranged so as to be larger in size than said display patterns on said liquid crystal display element and smaller in size than said polarizing plates of said first polarizer.

3. A liquid crystal display device as claimed in claim 1, wherein said transflector is formed of a diffusion reflecting member and a thin metallic film coated on one surface of said diffusion reflecting member, said thin metallic film being semi-transparent and disposed in contact with said color filter.

4. A liquid crystal display device comprising:

a front panel having displays indicating display contents on a surface of a transparent substrate;

a plurality of light sources for causing illuminating light to be incident upon said front panel through an end surface thereof;

a TN type liquid crystal display element having a plurality of display portions formed into a predetermined pattern;

a background plate disposed between said liquid crystal display element and said front panel, said background plate being provided with a plurality of windows through which said display portions of said liquid crystal display element are viewed by a medium of said front panel, said background plate having a remaining portion shielded from light;

a first polarizer and a second polarizer disposed so as to entirely cover said liquid crystal display element and having respective light absorbing axes parallel to each other;

a color filter having colored portions formed into a pattern identical to said predetermined pattern of said display portions of said liquid crystal display element, said colored portions being larger than their associated windows on said background plate and slightly larger than their associated display portions of the liquid crystal display element;

a transflector disposed in contact with said color filter; and

an internal light source for illuminating said color filter through said transflector.

5. A liquid crystal display device as claimed in claim 4, further comprising a plurality of light sources for causing differently colored illuminating light to be incident upon said front panel through an end surface thereof and a means for changing lighting of said light sources.