Liquid crystal display device

• US 5,774,199 A
• Filed: 03/26/1996
• Issued: 06/30/1998
• Est. Priority Date: 03/31/1995
• Status: Expired due to Fees

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Ozawa, Takaaki
• Primary Examiner(s): Sikes, William L.
• Assistant Examiner(s): TON, MINH TOAN T
• Application Number:
  US08/621,834
• Time in Patent Office: 826 Days
• Field of Search: 359/88, 359/49, 359/55, 359/54, 349/149, 349/62, 349/152, 349/143, 349/63
• US Class Current: 349/149
• CPC Class Codes: G02F 1/133334 Electromagnetic shields
• CPC Class Codes: G02F 1/133615 Edge-illuminating devices, i.e. illuminating from the side
• CPC Class Codes: G02F 1/13452 Conductors connecting driver circuitry and terminals of panels
• CPC Class Codes: H05K 3/325 by abutting or pinching, i.e. without alloying process; mechanical auxiliary parts therefor adaptations of leads inserted in holes for press-fit connections H05K3/308

Abstract

A liquid crystal display device connecting a circuit board to a liquid crystal display panel through at least one elastic conductor is disclosed herein. In addition to the elastic conductor connecting between the circuit board and the liquid crystal display panel, the liquid crystal display device includes a lamp for radiating a light toward the liquid crystal display panel and a light guide plate disposed between the circuit board and the liquid crystal display panel for conducting the light from the lamp toward the display area of the liquid crystal display panel. The light guide plate includes a positioning portion for surrounding and positioning at least three sides of the elastic conductor and has a height equal to or lower than that of the elastic conductor when it is in its compressed state. The lamp is disposed between the elastic conductor and the display area.

Claims

1. A liquid crystal display device comprising:

a circuit board having an electrically conductive pattern;

a liquid crystal display panel including a central display area and a plurality of electrode terminals disposed along a plurality of sides and connected to said conductive pattern, said liquid crystal display panel being disposed opposite to said circuit board;

at least one elastic conductor disposed and compressed between said circuit board and said liquid crystal display panel for connecting part of said electrode terminals disposed along at least one side of said plurality of sides in said liquid crystal display panel to said conductive pattern of said circuit board;

a lamp for radiating a light toward said liquid crystal display panel; and

a light guide plate disposed between said circuit board and said liquid crystal display panel for conducting the light from said lamp to said central display area of said liquid crystal display panel,

said light guide plate having at least one positioning portion for positioning said elastic conductor such that at least three sides of said at least one elastic conductor are surrounded by said positioning portion, said positioning portion having a height equal to or lower than that of said compressed elastic conductor, said lamp being disposed at a position between said elastic conductor and said central display area.

2. A liquid crystal display device as defined in claim 1 wherein said light guide plate includes a portion receiving said lamp.

3. A liquid crystal display device as defined in claim 1 wherein said plurality of electrode terminals are disposed on said liquid crystal display panel along the opposite sides thereof and connected to the electrically conductive pattern of said circuit board through two of said elastic conductors and wherein two positioning portions for positioning said two elastic conductors are formed in said light guide plate on the opposite sides thereof.

4. A liquid crystal display device as defined in claim 3 wherein said light guide plate includes a thin-walled portion formed at an area opposite to the central display area of said liquid crystal display panel and two thick-walled portions extending toward said circuit board and formed at a position incorporating the two positioning portions and having its thickness larger than that of said thin-walled portion.

5. A liquid crystal display device as defined in claim 4 wherein one of said thick-walled portions is formed with a recess for receiving said lamp.

6. A liquid crystal display device as defined in claim 5 wherein said recess has an opening faced to the liquid crystal display panel and a bottom opposite to said opening and wherein a terminal insertion aperture for receiving the terminals of the lamp is formed through the bottom of the recess.

7. A liquid crystal display device as defined in claim 1 wherein a first reflector for reflecting the light from the lamp is further provided between the circuit board and the light guide plate and wherein a supporting portion for supporting the first reflector is formed on the surface of said light guide plate opposite to said circuit board.

8. A liquid crystal display device as defined in claim 1 wherein a second reflector for reflecting the light from said lamp is further provided at least between said lamp and said at least one elastic conductor.

9. A liquid crystal display device as defined in claim 8 wherein said second reflector is formed of a reflective material which is applied to the side of said at least one elastic conductor opposite to said lamp.

10. A liquid crystal display device as defined in claim 8 wherein said second reflector is in the form of a reflecting sheet applied to the side of said at least one elastic conductor opposite to said lamp.

11. A liquid crystal display device as defined in claim 3 wherein said liquid crystal display panel includes a plurality of scan electrode terminals disposed on said liquid crystal display panel along first and second opposing sides thereof and a plurality of signal electrode terminals disposed on said liquid crystal display panel along a third side between the first and second sides and wherein said plurality of scan electrode terminals disposed on said liquid crystal display panel along the first and second sides thereof are connected to the conductive pattern on said circuit board through the two elastic conductors.

12. A liquid crystal display device as defined in claim 11, further comprising a flexible circuit board for connecting said plurality of signal electrode terminals in said liquid crystal display panel to the conductive pattern of said circuit board.

13. A liquid crystal display device as defined in claim 12 wherein the flexible circuit board simultaneously supplies the same signal to two of said signal electrode terminals which are disposed at positions axisymmetrical with each other about a center line bisecting said plurality of signal electrode terminals.

14. A liquid crystal display device comprising:

a circuit board having an electrically conductive pattern;

a substantially rectangular liquid crystal display panel having a pair of shorter sides and a pair of longer sides, said liquid crystal display panel including a central display area, a plurality of single electrode terminals disposed along at least one of said pair of longer sides and a plurality of scan electrode terminals disposed along said pair of shorter sides and connected to said electrically conductive pattern, said liquid crystal display panel being disposed opposite to said circuit board, and comprising a flexible circuit board for connecting said plurality of signal electrode terminals to the conductive pattern of said circuit board,

wherein the flexible circuit board simultaneously supplies the same signal to two of said signal electrode terminals which are disposed at positions axisymmetrical with each other about a center line bisecting said plurality of signal electrode terminals;

two elastic conductors disposed and compressed between said circuit board and said liquid crystal display panel for connecting said plurality of electrode terminals disposed along at least two sides of said liquid crystal display panel to said electrically conductive pattern of said circuit board;

a lamp for radiating a light toward said liquid crystal display panel; and

a light guide plate disposed between said circuit board and said liquid crystal display panel for conducting the light from said lamp toward said liquid crystal display panel,

said lamp being disposed between at least one of said elastic conductors and said display area,

said light guide plate including a reflecting sheet on a top face, an outer periphery face and a bottom face of the light guide plate for avoiding any external leakage of the light from the lamp.

15. The liquid crystal display device as defined in claim 14, further comprising a first shield plate positioned between the light guide plate and the circuit board.

16. The liquid crystal display device as defined in claim 15, further comprising a second shield plate mounted on a bottom surface of the circuit board.