Liquid crystal display device

• US 7,903,219 B2
• Filed: 07/29/2008
• Issued: 03/08/2011
• Est. Priority Date: 08/16/2007
• Status: Active Grant

• Current Assignee: Japan Display West Incorporated (Japan Display Incorporated)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Morifuji, Togo, Yamamoto, Yuji, Sakurai, Toru
• Primary Examiner(s): Kianni; K. Cyrus
• Application Number:
  US12/181,877
• Publication Number:
  US 20090046230A1
• Time in Patent Office: 952 Days
• Field of Search: 349/138, 349/139
• US Class Current: 349/138
• CPC Class Codes: G02F 1/133345 Insulating layers G02F1/1335, G02F1/1337, G02F1/135, G02F1/136 take precedence
• CPC Class Codes: G02F 1/134363 for applying an electric field parallel to the substrate, i.e. in-plane switching [IPS]
• CPC Class Codes: G02F 1/134372 for fringe field switching [FFS] where the common electrode is not patterned

Abstract

A liquid crystal display device includes a pair of substrates opposing each other, a liquid crystal layer disposed between the pair of substrates, and a pair of electrodes separated by an insulating layer, disposed on one of the substrates. The pair of electrodes drives the liquid crystal layer. The insulating layer has a compressive stress in the range of 0 to 5×10⁴ N/cm².

Claims

1. A liquid crystal display device comprising:

a pair of substrates opposing each other;

a liquid crystal layer disposed between the pair of substrates; and

a pair of electrodes separated by an insulating layer, disposed on one of the substrates, the pair of electrodes driving the liquid crystal layer, a first one of the electrodes being disposed closer to the liquid crystal layer than a second one of the electrodes and having apertures,

wherein the insulating layer has a compressive stress in the range of 0 to 5×

10⁴ N/cm².

2. The liquid crystal display device according to claim 1, wherein the insulating layer and the pair of electrodes define a storage capacitor.

3. The liquid crystal display device according to claim 1, wherein the insulating layer is made of an inorganic insulating material.

4. The liquid crystal display device according to claim 3, wherein the inorganic insulating material has a refractive index in the range of 1.46 to 2.00 and a dielectric constant in the range of 4 to 7.

5. The liquid crystal display device according to claim 1, wherein the insulating layer includes at least one film selected from the group consisting of a silicon nitride film, a silicon oxide film, and a silicon oxynitride film.

6. The liquid crystal display device according to claim 1, further comprising a transistor on the substrate on which the pair of electrodes is disposed, and a planarizing layer disposed over the transistor, wherein the electrodes separated by the insulating layer are disposed on the planarizing layer.

7. The liquid crystal display device according to claim 1, wherein the second one of the electrodes acts as a pixel electrode and the first one of the electrodes acts as a common electrode.

8. The liquid crystal display device according to claim 7, wherein at least one of the electrodes is made of a transparent electroconductive film.

9. The liquid crystal display device according to claim 1, further comprising a transistor and a planarizing layer in that order on the substrate on which the pair of electrodes are disposed, wherein the electrodes separated by the insulating layer are disposed on the planarizing layer, and the second one of the electrodes is made of a transparent electroconductive film, and wherein the insulating layer is formed under conditions that the planarizing layer and the second one of the electrodes made of the transparent electroconductive film are not degraded.

10. The liquid crystal display device according to claim 9, wherein the insulating layer is made of an inorganic insulating material, and the planarizing layer is made of an organic insulating material.

11. The liquid crystal display device according to claim 9, wherein the insulating layer has a refractive index in the range of 1.46 to 2.00 and a dielectric constant in the range of 4 to 7.