Liquid crystal display device

• US 9,213,202 B2
• Filed: 07/24/2014
• Issued: 12/15/2015
• Est. Priority Date: 07/21/2011
• Status: Active Grant

• Current Assignee: Japan Display Incorporated
• Original Assignee: Japan Display Incorporated
• Inventors: Tomioka, Yasushi, Kunimatsu, Noboru, Sonoda, Hidehiro, Imanishi, Yasuo, Igeta, Koichi
• Primary Examiner(s): NGUYEN, THANH NHAN P
• Application Number:
  US14/339,492
• Publication Number:
  US 20140333885A1
• Time in Patent Office: 509 Days
• Field of Search: 349/157, 349/155
• US Class Current: 1/1
• CPC Class Codes: G02F 1/1339 Gaskets; Spacers; Sealing of cells
• CPC Class Codes: G02F 1/13392 spacers dispersed on the cell substrate, e.g. spherical particles, microfibres
• CPC Class Codes: G02F 1/13394 spacers regularly patterned on the cell subtrate, e.g. walls, pillars G02F1/133377 takes precedence
• CPC Class Codes: G02F 1/13396 Spacers having different sizes
• CPC Class Codes: G02F 1/136227 Through-hole connection of the pixel electrode to the active element through an insulation layer

Abstract

A display device includes a first substrate having a plurality of TFTs, a passivation film, and a plurality of pixel electrodes, and a second substrate arranged with a gap with the first substrate. The passivation film has a plurality of contact holes, and the plurality of pixel electrodes are connected to the plurality of TFTs via the plurality of contact holes. The second substrate has a plurality of columnar spacers for ensuring the gap with the first substrate, and a plurality of columnar projections for misalignment prevention formed at positions corresponding to the contact holes. The number of the plurality of columnar projections is less than the number of the plurality of columnar spacers.

Claims

1. A display device, comprising:

a first substrate having a plurality of TFTs, a passivation film, and a plurality of pixel electrodes; and

a second substrate arranged with a gap with the first substrate;

wherein the passivation film has a plurality of contact holes, and the plurality of pixel electrodes are connected to the plurality of TFTs via the plurality of contact holes;

wherein the second substrate has a plurality of columnar spacers for ensuring the gap with the first substrate, and a plurality of columnar projections for misalignment prevention formed at positions corresponding to the contact holes;

wherein the number of the plurality of columnar projections is less than the number of the plurality of columnar spacers; and

wherein an interval between a pair of the plurality of columnar projections is larger than an interval between a pair of the plurality of columnar spacers.

2. A display device according to claim 1, wherein the passivation film includes an organic insulation film.

3. A display device according to claim 1, wherein the passivation film includes an inorganic insulating film.

4. A display device according to claim 1, wherein a difference Δ

h between the height h1 of one of the columnar projections and height h2 of one of the columnar spacers is equal to or less than depth z of the contact hole.

5. A display device according to claim 4, wherein each of the columnar projections abuts on a bottom part of each of the contact holes when an excessive force is applied thereto.

6. A display device according to claim 1, wherein height h1 of one of the columnar projections is larger than the gap d, and is smaller than a sum of the gap d and depth z of the contact hole.

7. A display device according to claim 1, wherein each of the contact holes has inclining part diameter which is larger at an upper part of the contact hole.

8. A display device according to claim 1, wherein a diameter of a top part of the columnar projection is smaller than a diameter of an upper part of the contact hole.

9. A display device according to claim 1, wherein a cross-sectional area of the columnar projection is smaller than a cross-sectional area of the columnar spacer.

10. A display device comprising:

a first substrate having a plurality of TFTs, a passivation film, and a plurality of pixel electrodes; and

a second substrate arranged with a gap with the first substrate;

wherein the passivation film has a plurality of contact holes, and the plurality of pixel electrodes are connected to the plurality of TFTs via the plurality of contact holes;

wherein the second substrate has a plurality of columnar spacers for ensuring the gap with the first substrate, and a plurality of columnar projections for misalignment prevention formed at positions corresponding to the contact holes;

wherein the number of the plurality of columnar projections is less than the number of the plurality of columnar spacers; and

wherein density of the plurality of columnar projections is higher at a peripheral area of the display device than at a center area of the display device.