Display device with field generating electrodes

• US 7,842,950 B2
• Filed: 05/02/2005
• Issued: 11/30/2010
• Est. Priority Date: 11/25/2004
• Status: Active Grant

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Song, Jang-Kun
• Primary Examiner(s): Fahmy; Wael M
• Assistant Examiner(s): ARMAND, MARC ANTHONY
• Application Number:
  US11/120,599
• Publication Number:
  US 20060108584A1
• Time in Patent Office: 2,038 Days
• Field of Search: 257/57, 257/59, 257/72, 257/83, 257/257, 257/290, 257/351, 257/368, 257/392, 257/252, 257/253, 257/254, 257/258, 257/E21.001, 257/E21, 257/E33.004, 257/E27.1, 257/E27.132, 257/E31.097, 438/22, 438/48
• US Class Current: 257/59
• CPC Class Codes: G02F 1/133707 Structures for producing distorted electric fields, e.g. bumps, protrusions, recesses, slits in pixel electrodes
• CPC Class Codes: G02F 1/134318 having a patterned common electrode
• CPC Class Codes: G02F 1/134345 Subdivided pixels, e.g. for grey scale or redundancy
• CPC Class Codes: G02F 1/1393 the birefringence of the liquid crystal being electrically controlled, e.g. ECB-, DAP-, HAN-, PI-LC cells G02F1/1396, G02F1/141 take precedence

Abstract

A display device including a first substrate, a first subpixel electrode, a second subpixel electrode corresponding to the first substrate, a second substrate and a common electrode formed on the second substrate is provided. The first subpixel electrode and the second subpixel electrode are formed on the first substrate. The second subpixel electrode is spaced apart from the first subpixel electrode. The common electrode has a first cutout and a second cutout. The first cutout is disposed over the first subpixel electrode and the second cutout is disposed over the second subpixel electrode. At least a portion of the first cutout has a first width and at least a portion of the second cutout has a second width different from the first width. The first width is larger than the second width in one embodiment. This structure enhances the aperture ratio and the brightness of the display device. Failures such as a residual image, stain or fingerprint may be reduced and the picture quality is improved.

Claims

1. A display device comprising:

a first substrate;

a first subpixel electrode formed on the first substrate;

a second subpixel electrode formed on the same layer of the first substrate as the first subpixel electrode, the second subpixel electrode being spaced apart from the first subpixel electrode;

a coupling electrode contacting the first subpixel electrode, the coupling electrode overlapping and being capacitively coupled to the second subpixel electrode;

a second substrate overlying the first substrate;

a common electrode having a first cutout and a second cutout formed on the second substrate, the first cutout being disposed over the first subpixel electrode and the second cutout being disposed over the second subpixel electrode; and

a liquid crystal layer interposed between the first substrate and the second substrate,

wherein at least a portion of the first cutout has a first width and at least a portion of the second cutout has a second width different from the first width, and

wherein the coupling electrode overlaps at leas t one of the first cutout and the second cutout.

2. The display device of claim 1, wherein a voltage applied to the first subpixel electrode is different from a voltage applied to the second subpixel electrode.

3. The display device of claim 1, wherein the first width is larger than the second width by about 10% to about 62%.

4. The display device of claim 1, wherein the first width is larger than the second width by about 15% to about 40%.

5. The display device of claim 1, wherein the first width is larger than the second width by about 1.0 μ

m to about 4.0 μ

m.

6. The display device of claim 1, wherein the first width is larger than the second width by about 1.5 μ

m to about 3.0 μ

m.

7. The display device of claim 1, wherein a voltage applied to the second subpixel electrode corresponds to about 60% to 80% of a voltage applied to the first subpixel electrode.