Liquid crystal display device

• US 8,018,558 B2
• Filed: 03/19/2009
• Issued: 09/13/2011
• Est. Priority Date: 03/19/2008
• Status: Active Grant

• Current Assignee: Panasonic Intellectual Property Corporation of America (Panasonic Holdings Corporation)
• Original Assignee: Hitachi Displays Limited (Japan Display Incorporated)
• Inventors: Kubota, Hidenao, Miwa, Hiroaki
• Primary Examiner(s): WONG, TINA MEI SENG
• Application Number:
  US12/406,999
• Publication Number:
  US 20090237602A1
• Time in Patent Office: 908 Days
• Field of Search: None
• US Class Current: 349/122
• CPC Class Codes: C09K 2323/05 Bonding or intermediate layer characterised by chemical composition, e.g. sealant or spacer
• CPC Class Codes: G02F 1/1335 Structural association of cells with optical devices, e.g. polarisers or reflectors
• CPC Class Codes: G02F 2201/50 Protective arrangements
• CPC Class Codes: G02F 2202/28 Adhesive materials or arrangements
• CPC Class Codes: Y10T 428/2848 Three or more layers

Abstract

A face plate on which a frame is formed for improved design aesthetics is bonded to a top surface of an upper polarizer of a liquid crystal display panel with a pressure-sensitive adhesive material. The frame on the face plate is formed from five layers of printing. The pressure-sensitive adhesive material has a three-layer structure having a first pressure-sensitive adhesive member, a base material, and a second pressure-sensitive adhesive member. The first pressure-sensitive adhesive member is formed thicker than the second pressure-sensitive adhesive member, and hence the pressure-sensitive adhesive material can maintain a necessary thickness above the frame formed on the face plate. The reliability of adhesion between the face plate and the liquid crystal display panel is thus improved.

Claims

1. A liquid crystal display device with a liquid crystal display panel comprising:

a thin film transistor substrate on which pixel electrodes and thin film transistors for controlling signals to the pixel electrodes are arranged in a matrix pattern;

a color filter substrate on which color filters are formed in a manner that corresponds to the pixel electrodes;

an upper polarizer bonded to the color filter substrate;

a face plate formed of a resin, the face plate being placed on the upper polarizer;

a frame having multiple printed layers, the frame being formed on a perimeter of the face plate; and

a pressure-sensitive adhesive material interposed between the upper polarizer and the face plate, the pressure-sensitive adhesive material covering the frame, the pressure-sensitive adhesive material having a three-layer structure including a first pressure-sensitive adhesive member which adheres to the face plate, a base material, and a second pressure-sensitive adhesive member which adheres to the upper polarizer, the first pressure-sensitive adhesive member having a thickness at least 1.4 times a thickness of the second pressure-sensitive adhesive member;

wherein when a thickness of the frame is given as TP, and a thickness of the first pressure-sensitive adhesive member in other parts than where the first pressure-sensitive adhesive member overlaps with the frame is given as TA, TA is at least 2.5 times larger than TP.

2. A liquid crystal display device according to claim 1, wherein the first pressure-sensitive adhesive member is thicker than the second pressure-sensitive adhesive member by at least 20 μ

m.

3. A liquid crystal display device according to claim 1, wherein the frame is formed of at least three layers, and the at least three layers are arranged so that positions of front edges on a center side of the face plate are progressively shifted outward, with a front edge of a layer of the at least three layers that is closest to the upper polarizer being farthest from the center side of the face plate.

4. A liquid crystal display device according to claim 1, wherein the face plate is formed of an acrylic resin.

5. A liquid crystal display device according to claim 1, wherein the thickness of the first pressure-sensitive adhesive member with respect to the second pressure-sensitive adhesive member, and to the thickness of the other parts of the first pressure-sensitive adhesive member where the first pressure-sensitive adhesive member overlaps with the frame are sufficient to enable good adhesion with the faceplate during usage of the liquid crystal display device.