Dot-matrix liquid crystal display

• US 4,770,498 A
• Filed: 09/18/1986
• Issued: 09/13/1988
• Est. Priority Date: 07/12/1982
• Status: Expired due to Term

• Current Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Original Assignee: Hosiden Electronics Co. Ltd. (Hosiden Corporation)
• Inventors: Ukai, Yasuhiro, Aoki, Shigeo, Tamamura, Junichi
• Primary Examiner(s): Miller, Stanley D.
• Assistant Examiner(s): Phan, Trong Q.
• Application Number:
  US06/908,981
• Time in Patent Office: 726 Days
• Field of Search: 350/334, 350/336, 357/23.7, 340/718, 340/719
• US Class Current: 349/47
• CPC Class Codes: G02F 1/133514 Colour filters
• CPC Class Codes: G02F 1/1345 Conductors connecting electrodes to cell terminals
• CPC Class Codes: G02F 1/13454 Drivers integrated on the active matrix substrate G02F1/136277 takes precedence
• CPC Class Codes: G02F 1/1362 Active matrix addressed cells G02F1/134336, G02F1/134363 take precedence
• CPC Class Codes: G02F 1/1368 in which the switching element is a three-electrode device G02F1/136277 takes precedence

Abstract

A liquid crystal cell comprises a liquid crystal sealed between a pair of confronting transparent substrates. A multiplicity of semiconductor driver elements are substantially uniformly distributed over an inner surface of one of the substrates. The semiconductor driver elements have output electrodes connected respectively to matrix element electrodes formed on the inner surface of said one of the substrates. A driver circuit is formed as a semiconductor integrated circuit on an extension of the inner surface of said one of the substrates for selectively driving the semiconductor driver elements.

Claims

1. A dot-matrix liquid crystal display comprising:

a first transparent substrate fabricated of an insulating material;

a second transparent substrate fabricated of an insulating material disposed closely adjacent and parallel to said first substrate and having marginal edges sealed to said first substrate to form a cell;

a liquid crystal sealed in said cell;

a common electrode deposited substantially entirely on an inner surface of said second substrate to define a display area of said liquid crystal display;

a plurality of row electrode lines formed in rows directly on said first substrate to extend along the respective rows of said matrix element electrodes;

a plurality of transparent matrix element electrodes formed in rows and columns directly on said first substrate to define display elements of the dot-matrix within said display area;

element drive thin-film transistors arranged in rows and columns on said first substrate within said display area, each of said thin-film transistors having a transparent source electrode formed directly on said first substrate in connection with a corresponding one of said row electrode lines, a transparent drain electrode formed directly on said first substrate integrally with a corresponding one of said matrix element electrodes, said source and drain electrodes being closely adjacent to one another, first and second ohmic contact layers formed on opposite edge portions of respective ones of said source and drain electrodes, a semiconductor layer formed on said first substrate to extend between and overlie said opposite edge portions of said first and second ohmic contact layers, a gate insulation film formed to cover said semiconductor layer, and a gate electrode formed on said gate insulation film in spaced facing relation to said semiconductor layer, said gate insulation film substantially entirely covering said display area; and

column electrode lines formed integrally with the corresponding columns of said gate electrodes on said gate insulation film in a direction perpendicular to said row electrode lines.

2. A dot-matrix liquid crystal display according to claim 1 wherein said opposite edge portions of said source and drain electrodes are tapered to approach each other on the side of said first substrate, and said first and second ohmic contact layers completely cover the tapered edge portions of said source and drain electrodes, respectively.

3. A dot-matrix liquid crystal display according to claim 1 or 2, wherein sections of a light shielding layer are formed on said first substrate, a transparent insulating layer is coated thereover, and said thin film transistors are formed on said transparent insulating layer so that each section of said light shielding layer covers said semiconductor layer of the corresponding one of said thin film transistors when seen through said first substrate.

4. A dot-matrix liquid crystal display according to claim 1, wherein said row electrode lines are transparent electrodes formed integrally with corresponding ones of said source electrodes.