Capacitive in-cell touch screen and display device

• US 9,529,482 B2
• Filed: 11/25/2013
• Issued: 12/27/2016
• Est. Priority Date: 04/07/2013
• Status: Active Grant

• Current Assignee: Beijing BOE Optoelectronics Technology Co Ltd. (BOE Technology Group Co., Ltd.), BOE Technology Group Co., Ltd.
• Original Assignee: Beijing BOE Optoelectronics Technology Co Ltd. (BOE Technology Group Co., Ltd.), BOE Technology Group Co., Ltd.
• Inventors: Liu, Hongjuan, Dong, Xue, Wang, Haisheng, Yang, Shengji, Wang, Lei, Wang, Chunlei, Liu, Yingming, Ren, Tao, Zhao, Weijie, Ding, Xiaoliang
• Primary Examiner(s): Moon, Seokyun
• Application Number:
  US14/387,132
• Publication Number:
  US 20160188029A1
• Time in Patent Office: 1,128 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: G02F 1/13338 Input devices, e.g. touch panels
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/04166 Details of scanning methods, e.g. sampling time, grouping of sub areas or time sharing with display driving Synchronisation with the driving of the display or the backlighting unit to avoid interferences generated internally G06F3/04184
• CPC Class Codes: G06F 3/0443 using a single layer of sensing electrodes
• CPC Class Codes: G06F 3/0446 using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes

Abstract

In a capacitive in-cell touch screen and a display device, the common electrode layer connected in the entire surface in the array substrate is divided to form touch driving electrodes and common electrodes which are insulated from each other and alternatively disposed, touch sensing electrodes are disposed on the upper substrate and touch driving electrodes are driven in a time-division manner to realize touch function and display function. Disposing projections of touch sensing electrodes on the array substrate in areas where common electrodes are may reduce right opposite areas between touch sensing electrodes and touch driving electrodes, thereby reduce opposite capacitance; providing sides of touch driving electrodes and adjacent sides of common electrodes as broken lines and providing consistent shapes for touch sensing electrodes and common electrodes may increase opposite areas between touch driving electrodes and touch sensing electrodes, thereby increasing projection capacitance per unit area. By increasing the proportion of projection capacitance over opposite capacitance, it is possible to increase proportion of variation amount of mutual capacitance caused by finger touching, and hence improving the touch accuracy.

Claims

1. A capacitive in-cell touch screen, comprising an upper substrate, an array substrate with a common electrode layer and a liquid crystal layer between the upper substrate and the array substrate, wherein

the common electrode layer consists of a plurality of touch driving electrodes and a plurality of common electrodes, and the plurality of touch driving electrodes and the plurality of common electrodes are insulated from each other and disposed alternatively, and sides of each of the touch driving electrodes and sides of each of the common electrodes adjacent to the touch driving electrodes are both non-straight lines;

in a display time for one frame of picture, the touch driving electrodes are loaded with common electrode signals and touch scanning signals in a time-division manner;

the upper substrate has a plurality of touch sensing electrodes, of which orthogonal projections on the array substrate are located in areas where the common electrodes are, and the shape of the touch sensing electrodes coincide with the shape of the areas where the common electrodes are.

2. The touch screen of claim 1, wherein the non-straight lines of the sides of each touch driving electrode and the sides of each adjacent common electrode are both of step-like shapes fitting each other;

and/or,

the non-straight lines of the sides of each touch driving electrode and the sides of each adjacent common electrode are both of convexo-concave shapes fitting each other.

3. The touch screen of claim 1, wherein orthogonal projections of the touch sensing electrodes on the array substrate are smaller than corresponding areas where the common electrodes are.

4. The touch screen of claim 1, wherein a plurality of pixel units arranged in a matrix are formed in the capacitive in-cell touch screen;

the touch driving electrodes extend in a row direction of pixel units; and

the touch sensing electrodes and common electrodes extend in a column direction of pixel units.

5. The touch screen of claim 4, wherein the common electrodes are strip electrodes, each of the touch driving electrodes comprises a plurality of touch driving sub-electrodes disposed in a same row, and the touch driving sub-electrodes are located in a gap between adjacent common electrodes.

6. The touch screen of claim 5, wherein the array substrate has a plurality of touch driving signal lines between adjacent pixel units, and each touch driving sub-electrode of the touch driving electrode is electrically connected with each other through at least one touch driving signal line.

7. The touch screen of claim 6, wherein the array substrate has a plurality of common electrode signal lines between adjacent pixel units, and the common electrodes are electrically connected with the common electrode signal lines.

8. The touch screen of claim 7, wherein in the array substrate, every two adjacent rows of pixel units are grouped as one pixel unit group, there are two gate signal lines between these two rows of pixel units for providing a gate scanning signal to one of the two rows of pixel units respectively.

9. The touch screen of claim 8, wherein the touch driving signal lines are located in gaps between adjacent pixel unit groups, and the common electrode signal lines are located in gaps between adjacent pixel unit groups other than those gaps where the touch driving signal lines are disposed.

10. The touch screen of claim 9, wherein the touch driving signal lines and the common electrode signal lines are disposed in a same layer as the gate signal lines in the array substrate;

the touch driving signal lines are electrically connected with corresponding touch driving sub-electrodes through at least one via hole; and

the common electrode signal lines are electrically connected with corresponding common electrodes through at least one via hole.

11. The touch screen of claim 1, wherein the touch sensing electrodes are located on one side of a black matrix area of the upper substrate that faces the liquid crystal layer.

12. The touch screen of claim 1, wherein the touch sensing electrodes have a grid-like electrode structure covered by the black matrix area.

13. The touch screen of claim 1, wherein a material for the touch sensing electrode is a transparent conducting material or a metallic material.

14. A display device comprising the capacitive in-cell touch screen of claim 1.

15. The touch screen of claim 2, wherein orthogonal projections of the touch sensing electrodes on the array substrate are smaller than corresponding areas where the common electrodes are.

16. The touch screen of claim 2, wherein a plurality of pixel units arranged in a matrix are formed in the capacitive in-cell touch screen;

the touch driving electrodes extend in a row direction of pixel units; and

the touch sensing electrodes and common electrodes extend in a column direction of pixel units.

17. The touch screen of claim 3, wherein a plurality of pixel units arranged in a matrix are formed in the capacitive in-cell touch screen;

the touch driving electrodes extend in a row direction of pixel units; and

the touch sensing electrodes and common electrodes extend in a column direction of pixel units.