Method of driving touch display and touch display capable of increasing signal-to-noise ratio

• US 9,019,235 B2
• Filed: 11/25/2013
• Issued: 04/28/2015
• Est. Priority Date: 07/22/2013
• Status: Expired due to Fees

• Current Assignee: Chunghwa Picture Tubes Limited (Tatung Co., Ltd.)
• Original Assignee: Chunghwa Picture Tubes Limited (Tatung Co., Ltd.)
• Inventors: Li, Yu-Chen, Hsu, Chao-Yong, Huang, Shih-Hung, Chen, Hung-Hsiang
• Primary Examiner(s): Lee, Gene W
• Application Number:
  US14/088,444
• Publication Number:
  US 20150022486A1
• Time in Patent Office: 519 Days
• Field of Search: 345173-183
• US Class Current: 345/174
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/04184 Synchronisation with the driving of the display or the backlighting unit to avoid interferences generated internally
• CPC Class Codes: G06F 3/044 by capacitive means

Abstract

A method of driving touch display includes a switching circuit driving each block of N blocks of a touch panel to display a corresponding image according to a driving signal generated by a liquid crystal driving unit during a first predetermined time within each horizontal synchronization signal period corresponding to the block between two vertical synchronization signals of the touch panel; the switching circuit executing touch scanning on M blocks of the N blocks only corresponding to the block according to touch scanning signals generated by a touch control unit during a second predetermined time within the horizontal synchronization signal period; and the touch control unit receiving and processing a touch scanning result corresponding to each block of the M blocks through the switching circuit during a third predetermined time within the horizontal synchronization signal period, where N and M are integers, and M is smaller than N.

Claims

1. A method of driving touch display, wherein the touch display comprises a liquid crystal driving unit, a touch control unit, a switching circuit, and a touch panel, wherein the touch panel comprises N blocks, and N is a positive integer, the method comprising:

the switching circuit driving each block of the N blocks to display a corresponding image according to a driving signal generated by the liquid crystal driving unit during a first predetermined time within each horizontal synchronization signal period corresponding to the block between two vertical synchronization signals of the touch panel;

the switching circuit executing touch scanning on M blocks of the N blocks only corresponding to the block according to touch scanning signals generated by the touch control unit during a second predetermined time within the horizontal synchronization signal period, wherein M is a positive integer, M is less than N, and the second predetermined time overlaps the first predetermined time; and

the touch control unit receiving and processing a touch scanning result corresponding to each block of the M blocks through the switching circuit during a third predetermined time within the horizontal synchronization signal period after the second predetermined time;

wherein during the second predetermined time, the touch control unit does not receive and process any touch scanning result; and

during the third predetermined time, the switching circuit does not execute any touch scanning.

2. The method of claim 1, wherein the block comprises a plurality of pixel lines, and each pixel line of the plurality of pixel lines corresponds to a horizontal synchronization signal of the touch panel.

3. The method of claim 1, wherein the touch panel is an in-cell capacitive touch panel.

4. The method of claim 1, wherein the touch panel is an on-cell capacitive touch panel.

5. The method of claim 1, wherein the second predetermined time is less than the first predetermined time.

6. The method of claim 5, wherein the third predetermined time is less than or equal to a difference between the first predetermined time and the second predetermined time.

7. A touch display capable of increasing signal-to-noise ratio, the touch display comprising:

a liquid crystal driving unit;

a touch control unit;

a switching circuit; and

a touch panel comprising N blocks, and N is a positive integer;

wherein the switching circuit drives each block of the N blocks to display a corresponding image according to a driving signal generated by the liquid crystal driving unit during a first predetermined time within each horizontal synchronization signal period corresponding to the block between two vertical synchronization signals of the touch panel;

the switching circuit executes touch scanning on M blocks of the N blocks only corresponding to the block according to touch scanning signals generated by the touch control unit during a second predetermined time within the horizontal synchronization signal period, wherein M is a positive integer, M is less than N, and the second predetermined time overlaps the first predetermined time; and

the touch control unit receives and processes a touch scanning result corresponding to each block of the M blocks through the switching circuit during a third predetermined time within the horizontal synchronization signal period after the second predetermined time; and

wherein during the second predetermined time, the touch control unit does not receive and process any touch scanning result; and

during the third predetermined time, the switching circuit does not execute any touch scanning.

8. The touch display of claim 7, wherein the block comprises a plurality of pixel lines, and each pixel line of the plurality of pixel lines corresponds to a horizontal synchronization signal of the touch panel.

9. The touch display of claim 7, wherein the second predetermined time is less than the first predetermined time.

10. The touch display of claim 9, wherein the third predetermined time is less than or equal to a difference between the first predetermined time and the second predetermined time.