TOUCH SCREEN, DRIVING METHOD THEREOF AND DISPLAY DEVICE

• US 20150205428A1
• Filed: 06/18/2013
• Published: 07/23/2015
• Est. Priority Date: 03/29/2013
• Status: Active Grant

• Current Assignee: BOE Technology Group Co., Ltd.
• Original Assignee: BOE Technology Group Co., Ltd.
• Inventors: Wang, Xiaolin
• Granted Patent: US 9,851,831 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 2203/04112 Electrode mesh in capacitive digitiser: electrode for touch sensing is formed of a mesh of very fine, normally metallic, interconnected lines that are almost invisible to see. This provides a quite large but transparent electrode surface, without need for ITO or similar transparent conductive material
• 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

Abstract

A touch screen, a driving method thereof and a display device. Common electrodes (9) of at least part of pixel units (5) on an array substrate (1) form a plurality of touch driving electrodes (3) each comprising at least one common electrode (9); the plurality of touch driving electrodes (3) are grouped into a plurality of touch driving electrode groups (101, 102) each comprising at least one touch driving electrode (3), and a plurality of touch sensing electrodes (4) are formed on a color filter substrate (2), the touch driving electrodes (3) and the touch sensing electrodes (4) are disposed to be intersected horizontally and vertically. Further, a driving circuit (10) is further provided, during a display period in a display time for one frame of picture, a common electrode signal is transferred by the driving circuit (10) to all of the touch driving electrodes (3), while during a touch period in the display time for the one frame of picture, a touch scan signal is only transferred by the driving circuit (10) to the respective touch driving electrodes in one of the touch driving electrode groups (101, 102).

Claims

1. A touch screen comprising a color filter substrate, an array substrate and a liquid crystal layer disposed between the array substrate and the color filter substrate, a plurality of pixel units which are arranged in a matrix are formed on the array substrate, the pixel unit comprises thin film transistors, a pixel electrode and a common electrode, characterized in that the common electrodes of at least part of the plurality of the pixel units on the array substrate constitute a plurality of touch driving electrodes each comprising at least one common electrode;

the plurality of the touch driving electrodes are grouped into a plurality of touch driving electrode groups each comprising at least one touch driving electrode; and

a plurality of touch sensing electrodes are formed on the color filter substrate;

wherein the touch driving electrode and the touch sensing electrodes are disposed to be intersected horizontally and vertically;

the touch screen further comprises a driving circuit for transferring a common electrode signal to all of the touch driving electrodes during a display period in a display time for one frame of picture, and only transferring a touch scan signal to the respective touch driving electrodes in one of the touch driving electrode groups sequentially during a touch period in the display time for the one frame of picture.

2. The touch screen of claim 1, characterized in that the plurality of touch driving electrodes are grouped into a first touch driving electrode group and a second touch driving electrode group.

3. The touch screen of claim 2, characterized in that each of the touch driving electrodes is arranged in a row direction of the pixel units, while each of the touch sensing electrodes is arranged in a column direction of the pixel units;

the first touch driving electrode group comprises all of the touch driving electrodes in odd rows;

while the second touch driving electrode group comprise all of the touch driving electrodes in even rows.

4. The touch screen of claim 3, characterized in that each of the touch driving electrodes is electrically connected with a drain of a corresponding switching thin film transistor;

sources of two switching thin film transistors corresponding to a touch driving electrode in the odd row and a touch driving electrode in the even row, which are adjacent, respectively, are electrically connected with each other and share one touch scan line;

the driving circuit comprises a touch switching driving circuit and a touch scan driving circuit;

the touch switching driving circuit is connected with gates of the respective switching thin film transistors and is used for transferring a touch switching signal to the gates of the respective switching thin film transistors to control turning on and off the switching thin film transistors;

the touch scan driving circuit is connected with the touch scan lines, and transfers the common electrode signal to all of the touch driving electrodes during the displaying periods in the display time for two consecutive frames of pictures while transfers the touch scan signal to the respective touch driving electrodes in the first touch driving electrode group and the second touch driving electrode group sequentially, respectively, during the touch periods in the display time for the two consecutive frames of pictures.

5. The touch screen of claim 4, characterized in that the gates of the switching thin film transistors corresponding to all of the touch driving electrodes in the odd rows share a first touch switching line;

while the gates of the switching thin film transistors corresponding to all of the touch driving electrodes in the even rows share a second touch switching line.

6. A display device, characterized by comprising the touch screen of claim 1.

7. A driving method for the touch screen of claim 1 in which a plurality of touch driving electrodes are grouped into a plurality of touch driving electrode groups in accordance with a certain rule, the driving method comprises:

dividing a display time for one frame of picture on the touch screen into a display period and a touch period;

during the display period in the display time for the one frame of picture, applying a common electrode signal to each of the touch driving electrodes in the touch screen and applying a low level signal to the touch sensing electrodes; and

during the touch period in the display time for the one frame of picture, only applying a touch scan signal to the respective touch driving electrodes in one of the touch driving electrode groups sequentially, and the touch sensing electrodes coupling the voltage signal of the touch scan signal and outputting the coupled voltage signal.

8. The driving method for the touch screen of claim 7, characterized in that the plurality of touch driving electrodes are grouped into a first touch driving electrode group and a second touch driving electrode group in accordance with the certain rule;

wherein, in the display time for two consecutive frames of pictures;

the common electrode signal is applied to each of the touch driving electrodes in the touch screen while the low level signal is applied to the touch sensing electrodes during the display period in the display time for the first frame of picture;

the touch scan signal is only applied to the respective touch driving electrodes in the first touch driving electrode group sequentially while the touch sensing electrodes couple the voltage signal of the touch scan signal and output the coupled voltage signals during the touch period in the display time for the first frame of picture;

the common electrode signal is applied to each of the touch driving electrodes in the touch screen while the low level signal is applied to the touch sensing electrodes during the display period in the display time for the second frame of picture;

the touch scan signal is only applied to the respective touch driving electrodes in the second touch driving electrode group sequentially while the touch sensing electrodes couple the voltage signal of the touch scan signal and output the coupled voltage signal during the touch period in the display time for the first frame of picture.

9. The driving method for the touch screen of claim 8, characterized in that in the touch screen:

each of the touch driving electrodes are arranged in a row direction of the pixel units, all of the touch driving electrodes in odd rows are grouped as the first touch driving electrode group and all of the touch driving electrodes in even rows are grouped as the second touch driving electrode group.

10. The driving method for the touch screen of claim 9, wherein in the touch screen, each touch driving electrode is electrically connected with a drain of a corresponding switching thin film transistor, sources of two switching thin film transistors corresponding to a touch driving electrode in the odd row and a touch driving electrode in the even row, which are adjacent, respectively, are electrically connected with each other and share one touch scan line;

characterized in that, in the driving method, in the display time for two consecutive frames of pictures,

the switching thin film transistors corresponding to all of the touch driving electrodes in the odd rows are controlled to be turned on and the touch scan signal is transferred to the respective touch driving electrodes in the first touch driving electrode group through touch scan lines sequentially during the touch period in the display time for the odd frame of picture;

the switching thin film transistors corresponding to all of the touch driving electrodes in the even rows are controlled to be turned on and the touch scan signal is transferred to the respective touch driving electrodes in the second touch driving electrode group through the touch scan lines sequentially during the touch period in the display time for the even frame of picture.

11. The driving method for the touch screen of claim 10, characterized in that during the touch period in the display time for the odd frame of picture, a touch switching signal is transferred to the gates of the switching thin film transistors corresponding to all of the touch driving electrodes in the odd rows through a first touch switching line so as to turn on the switching thin film transistors corresponding to all of the touch driving electrodes in the odd rows;

and

during the touch period in the display time for the even frame of picture, the touch switching signal is transferred to the gates of the switching thin film transistors corresponding to all of the touch driving electrodes in the even rows through a second touch switching line so as to turn on the switching thin film transistors corresponding to all of the touch driving electrodes in the even TOWS.

12. The display device of claim 6, characterized in that the plurality of touch driving electrodes are grouped into a first touch driving electrode group and a second touch driving electrode group.

13. The display device of claim 12, characterized in that each of the touch driving electrodes is arranged in a row direction of the pixel units, while each of the touch sensing electrodes is arranged in a column direction of the pixel units;

the first touch driving electrode group comprises all of the touch driving electrodes in odd rows;

while the second touch driving electrode group comprise all of the touch driving electrodes in even rows.

14. The display device of claim 13, characterized in that each of the touch driving electrodes is electrically connected with a drain of a corresponding switching thin film transistor;

sources of two switching thin film transistors corresponding to a touch driving electrode in the odd row and a touch driving electrode in the even row, which are adjacent, respectively, are electrically connected with each other and share one touch scan line;

the driving circuit comprises a touch switching driving circuit and a touch scan driving circuit;

the touch switching driving circuit is connected with gates of the respective switching thin film transistors and is used for transferring a touch switching signal to the gates of the respective switching thin film transistors to control turning on and off the switching thin film transistors;

the touch scan driving circuit is connected with the touch scan lines, and transfers the common electrode signal to all of the touch driving electrodes during the displaying periods in the display time for two consecutive frames of pictures while transfers the touch scan signal to the respective touch driving electrodes in the first touch driving electrode group and the second touch driving electrode group sequentially, respectively, during the touch periods in the display time for the two consecutive frames of pictures.

15. The display device of claim 14, characterized in that the gates of the switching thin film transistors corresponding to all of the touch driving electrodes in the odd rows share a first touch switching line;

while the gates of the switching thin film transistors corresponding to all of the touch driving electrodes in the even rows share a second touch switching line.

16. The driving method for the touch screen of claim 10, characterized in that the gates of the switching thin film transistors corresponding to all of the touch driving electrodes in the odd rows share a first touch switching line;

while the gates of the switching thin film transistors corresponding to all of the touch driving electrodes in the even rows share a second touch switching line.