Touch panel liquid crystal display device and method of fabricating the same

• US 6,914,640 B2
• Filed: 12/26/2002
• Issued: 07/05/2005
• Est. Priority Date: 12/27/2001
• Status: Expired due to Term

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Philips LCD Company Limited (LG Display Co., Ltd.)
• Inventors: Yu, Hwan Seong
• Primary Examiner(s): Chowdhury, Tarifur R.
• Assistant Examiner(s): QI, ZHI QIANG
• Application Number:
  US10/327,865
• Publication Number:
  US 20030122800A1
• Time in Patent Office: 922 Days
• Field of Search: 349/12, 349/96, 349/187, 349/153, 349/190, 349/155, 345/104, 345/173, 428/143
• US Class Current: 349/12
• CPC Class Codes: G02F 1/133 Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements arrangements or circuits for control of liquid crystal elements in a matrix, not structurally associated with these elements G09G3/36
• CPC Class Codes: G02F 1/13338 Input devices, e.g. touch panels
• CPC Class Codes: G06F 3/041 Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/045 using resistive elements, e.g. a single continuous surface or two parallel surfaces put in contact

Abstract

A touch panel integrated liquid crystal display device includes a liquid crystal display panel, a touch panel formed on the liquid crystal display panel, a polarizer formed between the liquid crystal display panel and the touch panel, a first adhesive formed between the touch panel and the polarizer, and a second adhesive formed between the polarizer and the liquid crystal display panel, wherein an adhesive strength of the second adhesive is larger than an adhesive strength of the first adhesive.

Claims

1. A touch panel integrated liquid crystal display device, comprising:

a liquid crystal display panel;

a touch panel formed on the liquid crystal display panel;

a polarizer formed between the liquid crystal display panel and the touch panel;

a first adhesive formed between the touch panel and the polarizer; and

a second adhesive formed between the polarizer and the liquid crystal display panel,

wherein an adhesive strength of the second adhesive is larger than an adhesive strength of the first adhesive.

2. The device according to claim 1, wherein the adhesive strength of the second adhesive is about 1 kg/25 mm.

3. The device according to claim 1, wherein the adhesive strength of the first adhesive is not more than about 1 kg/25 mm.

4. The device according to claim 1, wherein the touch panel includes:

an upper substrate having first and second surfaces;

a first electrode layer formed on the first surface of the upper substrate;

a lower substrate having first and second surfaces;

a second electrode layer formed on the first surface of the lower substrate; and

a spacer formed between the first surface of the upper substrate and the first surface of the lower substrate.

5. The device according to claim 4, wherein the polarizer is bonded to a second surface of the lower substrate by the first adhesive.

6. The device according to claim 4, wherein the first and second electrode layers include a transparent conductive material.

7. The device according to claim 6, wherein the first and second electrode layers include a silver material formed on the transparent conductive material.

8. The device according to claim 1, wherein the liquid crystal display panel includes:

an upper plate having first and second surfaces;

a lower plate having first and second surfaces; and

a spacer formed between the first surface of the upper plate and the first surface of the lower plate.

9. The device according to claim 8, wherein the polarizer is bonded to the second surface of the upper plate via the second adhesive.

10. The device according to claim 8, wherein the upper plate includes:

a black matrix formed on the second surface of the upper plate;

a color filter formed on the second surface of the upper plate and the black matrix;

a common electrode formed on the color filter; and

a first alignment film formed to cover the common electrode.

11. The device according to claim 10, wherein the polarizer is formed between the second surface of the upper plate of the liquid crystal display panel and the second surface of the lower plate of the touch panel.

12. The device according to claim 8, wherein the lower plate includes:

a gate line formed along a first direction on the first surface of the lower plate;

a data line formed along a second direction perpendicular to the first direction to cross the gate line;

a thin film transistor formed at an intersection of the gate line and the data line;

a pixel electrode connected to the thin film transistor; and

a second alignment film formed to cover the pixel electrode.

13. A method of fabricating a touch panel integrated liquid crystal display device, comprising the steps of:

forming a touch panel;

bonding a first surface of a polarizer on a first surface of the touch panel using a first adhesive; and

forming a liquid crystal display panel;

bonding a first surface of the liquid crystal display panel on a second surface of the polarizer using a second adhesive,

wherein an adhesive strength of the second adhesive is larger than an adhesive strength of the first adhesive.

14. The method according to claim 13, wherein the adhesive strength of the second adhesive is about 1 kg/25 mm.

15. The method according to claim 13, wherein the adhesive strength of the first adhesive is not more than about 1 kg/25 mm.

16. The method according to claim 13, wherein the step of forming a touch panel includes steps of:

forming a first electrode layer on a first surface of an upper substrate;

forming a second electrode layer on a first surface of a lower substrate; and

forming a spacer between the first surface of the upper substrate and the first surface of the lower substrate.

17. The method according to claim 16, wherein the first and second electrode layers include a transparent conductive material.

18. The method according to claim 17, wherein the first and second electrode layers include a silver material formed on the transparent conductive material.

19. The method according to claim 16, wherein the step of bonding a first surface of a polarizer includes bonding a second surface of the lower substrate by the first adhesive.

20. The method according to claim 13, wherein the step of forming a liquid crystal display panel includes forming a spacer between a first surface of an upper plate and a first surface of a lower plate.

21. The method according to claim 20, wherein the step of bonding a first surface of the liquid crystal display panel includes bonding the second surface of the polarizer to a second surface of the upper plate via the second adhesive.

22. The method according to claim 20, wherein the upper plate includes:

a black matrix formed on the second surface of the upper plate;

a color filter formed on the second surface of the upper plate and the black matrix;

a common electrode formed on the color filter; and

a first alignment film formed to cover the common electrode.

23. The method according to claim 20, wherein the lower plate includes:

a gate line formed along a first direction on the first surface of the lower plate;

a data line formed along a second direction perpendicular to the first direction to cross the gate line;

a thin film transistor formed at an intersection of the gate line and the data line;

a pixel electrode connected to the thin film transistor; and

a second alignment film formed to cover the pixel electrode.

24. The method according to claim 20, wherein the polarizer is formed between the second surface of the upper plate of the liquid crystal display panel and the second surface of the lower plate of the touch panel.