Display panel having noise shielding structure

• US 7,184,117 B2
• Filed: 06/29/2004
• Issued: 02/27/2007
• Est. Priority Date: 07/31/2003
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Suzuki, Isamu
• Primary Examiner(s): Nguyen; Dung T.
• Application Number:
  US10/878,397
• Publication Number:
  US 20050024573A1
• Time in Patent Office: 973 Days
• Field of Search: 349149-152, 349/58
• US Class Current: 349/150
• CPC Class Codes: G02F 1/133308 Support structures for LCD panels, e.g. frames or bezels
• CPC Class Codes: G02F 1/133334 Electromagnetic shields
• CPC Class Codes: G02F 1/13452 Conductors connecting driver circuitry and terminals of panels
• CPC Class Codes: H05K 1/0218 by printed shielding conductors, ground planes or power plane H05K1/0236 takes precedence
• CPC Class Codes: H05K 3/361 Assembling flexible printed circuits with other printed circuits

Abstract

A circuit board area is formed on a front glass substrate of a liquid crystal display (LCD) panel, and driver ICs are mounted in the circuit board section. The driver ICs are electrically connected to an external display control device via a flexible printed circuit board (FPC). A metal foil is attached to one side of the FPC for shielding unnecessary radiating noises. The metal foil has connecting flap portions and the flap portions are fixed to an outer case of a backlight unit with a metal foil tape. The metal foil tape is also bonded to an external frame of an LCD device. As a result, the metal foil is electrically connected with the external frame and the radiating noises are effectively reduced.

Claims

1. A display device comprising:

a display panel having a circuit board area in which electronic components are mounted;

a metal external frame that houses the display panel;

a connecting member that connects the circuit board area with an external electronic device; and

a shielding layer that shields a noise produced in the connecting member, wherein

the connecting member includes a flexible printed circuit board having a ground on a surface, and

the shielding layer is electrically connected with the around of the circuit board and the external frame.

2. The display device according to claim 1, wherein:

the display panel is constructed of two transparent plates and liquid crystal that is filled between the transparent panels;

one of the transparent plates is a glass substrate; and

the circuit board area is formed on the glass substrate.

3. The display device according to claim 1, wherein:

the connecting member is a flexible printed circuit board;

the flexible printed circuit board has first and second sides;

the shielding layer is bonded to at least one of the first and the second sides of the flexible printed circuit board.

4. The display device according to claim 1, wherein the shielding layer is formed with a metal foil.

5. The display device according to claim 4, wherein:

the connecting member has first and second sides;

the ground is provided on at least one of the first and second sides of the connecting member; and

the metal foil is arranged on at least one of the first and the second sides on which the ground is provided such that the metal foil has contact with the ground.

6. The display device according to claim 1, wherein the display device further comprises a connecting section through which the shielding layer is electrically connected with the external frame.

7. The display device according to claim 6, wherein the connecting section is a metal foil tape.

8. The display device according to claim 6, wherein:

the external frame has a bump portion that functions as the connecting member; and

the bump portion has contact with the shielding layer for electrically connecting the shielding layer with the external frame.

9. The display device according to claim 6, wherein:

the connecting member is an elastic tube provided by forming an electrically conductive member into a cylindrical shape;

the elastic tube is arranged between the shielding layer and the external frame for electrically connecting the shielding layer with the external frame through elasticity thereof.

10. The display device according to claim 9, wherein the elastic tube is made of an electrically conductive plastic.

11. The display device according to claim 1, wherein:

the surface of the flexible printed circuit board is covered with an insulating coating except for a land of the ground; and

the shielding layer is electrically connected to the land of the ground.

12. The display device according to claim 1, wherein the shielding layer is bonded to the connecting member to be electrically connected thereto.

13. The display device according to claim 1, further comprising an onboard device including a main body, wherein:

the main body has a display holding portion that is made of metal;

the display holding portion is connected with an external ground of the external electric device;

the external frame is fixed to the display holding portion; and

the shielding layer and the external frame are electrically connected with the display bolding portion.

14. The display device according to claim 1, wherein:

the connecting member has a substrate connecting portion connected to the circuit board area, and an external device connecting portion extending from the substrate connecting portion and connected to the external electronic device; and

the shielding layer covers at least a part of the substrate connecting portion and at least a part of the external device connecting portion.