Touch scanning method for touch screen, touch scanning control circuit and display device

• US 9,430,069 B2
• Filed: 03/17/2014
• Issued: 08/30/2016
• 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, Guo, Baolei, Wang, Shanrong, Wang, Xupeng, Ding, Xiaoyuan
• Primary Examiner(s): MANDEVILLE, JASON M
• Application Number:
  US14/217,144
• Publication Number:
  US 20150109217A1
• Time in Patent Office: 897 Days
• Field of Search: 345173-175, 178/18.01, 178/18.03, 178/18.05, 178/18.06
• US Class Current: 1/1
• 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 determined to be present, performing a coarse scanning on the touch screen, if a touch is determined to be present, performing a fine scanning on a full detection-activated region containing a touch point while performing a coarse scanning on a remaining region of the touch screen other than the full detection-activated region, the full detection-activated region being defined based on the touch point to be a subset of the plurality of drive lines and the plurality of sense lines of the touch screen; and

at the time when a determined present touch is released following the fine scanning on the full detection-activated region, maintaining the fine scanning on the full detection-activated region for a first time period, and subsequently performing the coarse scanning on the entire touch screen if a touch is not determined to be present when the first time period is expired;

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

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

in succeeding N frames of the M+N successive frames, stopping driving all of the plurality of drive lines on the entire touch screen and stopping detecting all of the plurality of sense lines on the entire touch screen;

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

wherein the fine scanning comprises, in 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;

wherein the coarse scanning is repeatedly performed if a touch is not determined to be present.

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

3. 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.

4. 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 response to a determined 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, the full detection-activated region being defined based on the touch position to be a subset of the plurality of drive lines and the plurality of sense lines of the touch screen,

wherein the control module is configured, if a touch is not determined to be present, to perform a coarse scanning on the touch screen, and the control module is configured, if a touch is determined to be present, to perform a fine scanning on the full detection-activated region containing the touch position while performing a coarse scanning on a remaining region other than the full detection-activated region; and

, at the time when a determined present touch is released following the fine scanning on the full detection-activated region, maintain the fine scanning on the full detection-activated region for a first time period, and subsequently perform the coarse scanning on the entire touch screen if a touch is not determined to be present when the first time period is expired;

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

wherein, in succeeding N frames of the M+N successive frames, all of the plurality of drive lines are stopped from being driven on the entire touch screen and all of the plurality of sense lines are stopped from being detected on the entire touch screen;

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;

wherein the coarse scanning is repeatedly performed if a touch is not determined to be present.

5. The touch scanning control circuit of claim 4, wherein M is equal to 1.

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

7. The touch scanning control circuit of claim 4, 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.

8. The touch scanning control circuit of claim 4, 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.

9. 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 response to a determined 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, the full detection-activated region being defined based on the touch position to be a subset of the plurality of drive lines and the plurality of sense lines of the touch screen;

wherein the control module is configured, if a touch is not determined to be present, to perform a coarse scanning on the touch screen, and the control module is configured, if a touch is determined to be present, to perform a fine scanning on the full detection-activated region containing the touch position while performing a coarse scanning on a remaining region other than the full detection-activated region; and

, at the time when a determined present touch is released following the fine scanning on the full detection-activated region, maintain the fine scanning on the full detection-activated region for a first time period, and subsequently perform the coarse scanning on the entire touch screen if a touch is not determined to be present when the first time period is expired;

wherein, in the coarse scanning, in first M frames of M+N successive frames, drive a set of drive lines of the plurality of drive lines spaced apart from one another by at least one of the plurality of drive lines, and detect a set of sense lines of the plurality of sense lines spaced apart from one another by at least one of the plurality of sense lines,

wherein, in succeeding N frames of the M+N successive frames, all of the plurality of drive lines are stopped from being driven on the entire touch screen and all of the plurality of sense lines are stopped from being detected on the entire touch screen;

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;

wherein the coarse scanning is repeatedly performed if a touch is not determined to be present.

10. The display device of claim 9, wherein M is equal to 1.

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

12. The display device of claim 9, 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.

13. The display device of claim 9, 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.