TOUCH SCANNING METHOD FOR TOUCH SCREEN, TOUCH SCANNING CONTROL CIRCUIT AND DISPLAY DEVICE

• US 20150109217A1
• Filed: 03/17/2014
• Published: 04/23/2015
• Est. Priority Date: 10/21/2013
• Status: Active Grant

• Current Assignee: Shanghai AVIC Optoelectronics Company Limited (Tianma Microelectronics Company Limited), Tianma Microelectronics Company Limited
• Original Assignee: Shanghai AVIC Optoelectronics Company Limited (Tianma Microelectronics Company Limited), Tianma Microelectronics Company Limited
• Inventors: ZHU, Zhifeng, WANG, Xupeng, GUO, Baolei, WANG, Shanrong, DING, Xiaoyuan
• Granted Patent: US 9,430,069 B2
• Time in Patent Office: Days
• US Class Current: 345/173
• CPC Class Codes: G06F 1/3262 Power saving in digitizer or tablet
• CPC Class Codes: G06F 3/041 Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
• 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 3/041661 using detection at multiple resolutions, e.g. coarse and fine scanning; using detection within a limited area, e.g. object tracking window
• 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
• CPC Class Codes: G06F 3/047 using sets of wires, e.g. crossed wires

Abstract

A touch scanning method includes, in the absence of a touch, performing a coarse scanning on the touch screen, and in the presence of a touch, performing a fine scanning on a full detection-activated region containing a touch point while performing the coarse scanning on the remaining region other than the full detection-activated region. During coarse scanning, in first M frames of M+N successive frames, drive lines spaced apart from one another by at least one of the drive lines are driven, and sense lines spaced apart from one another by at least one of the sense lines are detected. In the succeeding N frames of the M+N frames, there is no activity in the drive and sense lines. During the fine scanning, each drive line and each sense line within the full detection-activated region is driven and detected, respectively.

Claims

1. A method for scanning a touch screen comprising a plurality of drive lines and a plurality of sense lines arranged in a matrix, the method comprising:

if a touch is not present, performing a coarse scanning on the touch screen, and

if a touch is present, performing a fine scanning on a full detection-activated region containing a touch point, and performing a coarse scanning on a remaining region of the touch screen other than the full detection-activated region;

wherein, the coarse scanning comprises, in first M frames of M+N successive frames;

driving drive lines being spaced apart from one another by at least one of the drive lines, and detecting sense lines being spaced apart from one another by at least one of the sense lines; and

in succeeding N frames of the M+N successive frames, stopping driving the drive lines and stopping detecting the sense lines;

wherein M and N are integers equal to or greater than 1;

wherein the fine scanning comprises, in the M+N successive frames;

driving each of drive lines within the full detection-activated region; and

detecting each of sense lines within the full detection-activated region.

2. The method of claim 1, further comprising, if the touch is present:

maintaining the fine scanning on the full detection-activated region for a first time period; and

performing the coarse scanning on the touch screen.

3. The method of claim 1, wherein M and N are equal to 1.

4. The method of claim 1, wherein, in the coarse scanning, the driven drive lines are spaced apart from one another by one of the drive lines, and the detected sense lines are spaced apart from one another by one of the sense lines.

5. A touch scanning control circuit in electrical connection with a touch screen having a plurality of drive lines and a plurality of sense lines, the touch scanning control circuit comprises:

a data acquisition control module;

a position calculation and determination module;

a calculation module; and

a control module,

wherein the data acquisition control module is configured to acquire data in a presence of a touch and send the acquired data to the position calculation and determination module,

wherein the position calculation and determination module is configured to calculate a touch position based on the acquired data, determine a center position nearest to the touch position, and send the center position to the calculation module,

wherein the calculation module is configured to define a full detection-activated region,

wherein the control module is configured to perform a fine scanning on a full detection-activated region, and perform a coarse scanning on a remaining region other than the full detection-activated region,

wherein, in the coarse scanning, in first M frames of M+N successive frames, drive lines spaced apart from one another by at least one of the drive lines are driven, and sense lines spaced apart from one another by at least one of the sense lines are detected,

wherein, in succeeding N frames of the M+N successive frames, the drive lines are not driven and the sense lines are not detected;

M and N being integers equal to or greater than 1; and

wherein, in the fine scanning, in the M+N successive frames, each of drive lines within the full detection-activated region is driven, and each of sense lines within the full detection-activated region is detected.

6. The touch scanning control circuit of claim 5, wherein M is equal to 1.

7. The touch scanning control circuit of claim 6, wherein N is equal to 1.

8. The touch scanning control circuit of claim 5, wherein, in the coarse scanning controlled by the control module, the drive lines spaced apart from one another by one of the drive lines are driven, and the sense lines spaced apart from one another by one of the sense lines are detected.

9. The touch scanning control circuit of claim 5, wherein the calculation module defines, by taking the center position sent by the position calculation and determination module as a reference, an area surrounded by an i-th drive line ahead of the center position, a j-th drive line behind the center position, a k-th sense line on the left of the center position, and an l-th sense line on the right of the center position as the full detection-activated region, wherein i, j, k, l all are integers equal to or greater than 0.

10. A display device comprises:

a touch screen having a plurality of drive lines and a plurality of sense lines; and

a touch scanning control circuit in electrical connection with the touch screen, the touch scanning control circuit comprising a data acquisition control module, a position calculation and determination module, a calculation module, and a control module,

wherein the data acquisition control module is configured to acquire data in the presence of a touch and send the acquired data to the position calculation and determination module;

wherein the position calculation and determination module is configured to calculate a touch position based on the acquired data, determine a center position nearest to the touch position, and send the center position to the calculation module;

wherein the calculation module is configured to define a full detection-activated region;

wherein the control module is configured to perform a fine scanning on a full detection-activated region, and perform a coarse scanning on a remaining region other than the full detection-activated region;

wherein, in the coarse scanning, in first M frames of M+N successive frames, drive lines spaced apart from one another by least one of the drive lines, and sense lines spaced apart from one another by least one of the sense lines are detected,

wherein, in succeeding N frames from the M+N successive frames, the drive lines are not driven and the sense lines are not detected;

both M and N being integers equal to or greater than 1; and

wherein, in the fine scanning, in the M+N successive frames, each of drive lines within the full detection-activated region is driven and each of sense lines within the full detection-activated region is detected.

11. The display device of claim 10, wherein M is equal to 1.

12. The display device of claim 11, wherein N is equal to 1.

13. The display device of claim 10, wherein, in the coarse scanning controlled by the control module, the drive lines spaced apart from one another by one of the drive lines are driven, and the sense lines spaced apart from one another by one of the sense lines are detected.

14. The display device of claim 10, wherein the calculation module defines, by taking the center position sent by the position calculation and determination module as a reference, an area surrounded by an i-th drive line ahead of the center position, a j-th drive line behind the center position, a k-th sense line on the left of the center position, and an l-th sense line on the right of the center position as the full detection-activated region, wherein i, j, k, l are integers equal to or greater than 0.