Position-sensitive liquid crystal display and process for producing the same

• US 5,568,292 A
• Filed: 11/06/1995
• Issued: 10/22/1996
• Est. Priority Date: 09/09/1992
• Status: Expired due to Term

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: Goldstar Jewellery LLC
• Inventors: Kim, Jeong J.
• Primary Examiner(s): Sikes, William L.
• Assistant Examiner(s): MILLER, CHARLES LELAND
• Application Number:
  US08/554,106
• Time in Patent Office: 351 Days
• Field of Search: 359/67, 359/46, 359/68, 345/104
• US Class Current: 349/110
• CPC Class Codes: G02F 1/13338 Input devices, e.g. touch panels
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/0442 using active external devices, e.g. active pens, for transmitting changes in electrical potential to be received by the digitiser
• CPC Class Codes: G06F 3/046 by electromagnetic means

Abstract

A position-sensitive liquid crystal display applicable to a thin input-output pad utilized for a pen-based computer is disclosed, which employs the liquid crystal display endowed with a position-sensitive function and a simple process for producing the same, exclusive of superimposing the liquid crystal display on a position-sensitive device. The position-sensitive liquid crystal display includes an upper substrate having a position-sensitive device therein, a lower substrate joined with the upper substrate and a liquid crystal injected between the upper and the lower substrates. The process for producing the same omits the step of joining the liquid crystal display with the position-sensitive device and is thus simple.

Claims

1. A position-sensitive liquid crystal display comprising:

a lower glass substrate;

an upper glass substrate;

a plurality of transparent pixel electrodes formed on said lower glass substrate;

a plurality of thin film transistors associated with said transparent pixel electrodes formed on said lower glass substrate;

a position-sensitive layer formed on said upper glass substrate as a black matrix wherein said position-sensitive layer includes a plurality of X-directional grid wires, a plurality of Y-directional grid wires and an insulating layer therebetween;

a color filter formed directly on said X-directional grid wires of said position-sensitive layer; and

a liquid crystal material interposed between said lower glass substrate and said upper glass substrate.

2. The position-sensitive liquid crystal display of claim 1, further comprising:

a first polarizing screen applied to a surface of said upper glass substrate; and

a second polarizing screen applied to a surface of said lower glass substrate,

wherein said first and second polarizing screens form top and bottom surfaces of the position-sensitive liquid crystal display, respectively.

3. The position-sensitive liquid crystal display of claim 2, wherein said color filter is coated with a polyamide layer, said color filter having a plurality of color regions for displaying color.

4. The position-sensitive liquid crystal display of claim 3, wherein said plurality of X-directional grid wires and said plurality of Y-directional grid wires are arranged so as to define a plurality of areas, said plurality of areas directly corresponding with the plurality of color regions of said color filter.

5. The position-sensitive liquid crystal display of claim 4, further including:

an adhesive layer, a transparent counter electrode layer, and a first error aligning layer, sequentially applied to said color filter; and

a protective film and then a second error aligning layer deposited over said plurality of thin film transistors,

wherein said liquid crystal material is injected between the first and second error aligning layers.

6. The position-sensitive liquid crystal display of claim 5, further including means for processing signals generated from said position-sensitive layer to determine which portion of the liquid crystal display is being selected.

7. A process for producing a position-sensitive liquid crystal display, comprising the steps of:

depositing a metal layer on the surface of a first glass substrate;

patterning said metal layer in a desired shape to form a pattern of transparent picture element electrodes;

forming a plurality of thin film transistors over said pattern of transparent picture element electrodes;

depositing a protective film and a first error aligning layer, in sequence, over said plurality of thin film transistors to prepare a lower substrate;

depositing a Y-directional grid wire layer on a second glass substrate;

patterning the Y-directional grid wire layer in a desired shape;

depositing an insulating layer and then an X-directional grid wire layer, over said patterned Y-directional grid wire layer;

patterning the X-directional grid wire layer in a desired shape so as to provide a function of a black matrix in combination with the patterned Y-directional grid wire layer;

forming a color filter coated with a polyimide layer directly on said patterned X-directional grid wire layer;

forming an adhesive layer on said color filter;

depositing a transparent counter electrode and a second error aligning layer, in sequence, on said adhesive layer to form an upper substrate;

joining said lower substrate and said upper substrate together in such a manner that said first and second glass substrates are directed toward an outside of said position-sensitive liquid crystal display, respectively;

injecting a liquid crystal material between said lower substrate and said upper substrate; and

depositing a polarizing screen on each of the outside-directed surfaces of said first and second glass substrates, whereby said patterned Y-directional grid wire layers, said patterned X-directional grid wire layer, and said insulating layer therebetween form a position-sensitive device.