Touch screen and related touch sensing control circuit

• US 9,626,048 B2
• Filed: 04/07/2014
• Issued: 04/18/2017
• Est. Priority Date: 01/13/2014
• Status: Active Grant

• Current Assignee: Himax Technologies Ltd. (Himax Technologies Incorporated)
• Original Assignee: Himax Technologies Ltd. (Himax Technologies Incorporated)
• Inventors: He, Jia-Ming, Chang, Yaw-Guang, Hu, Chia-Wei
• Primary Examiner(s): Chang, Kent
• Assistant Examiner(s): Lu, William
• Application Number:
  US14/247,243
• Publication Number:
  US 20150199044A1
• Time in Patent Office: 1,107 Days
• 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 3/044 by capacitive means
• 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

Disclosed herein are touch screens that integrate touch sensing systems with display devices. The touch sensing system serves data lines and common electrodes of a driving circuitry of the display device as touch driving lines and touch sensing lines for touch sensing operations. A common electrode layer having the common electrodes of the driving circuitry includes a plurality of openings for reducing a base mutual-capacitance of the touch sensing system.

Claims

1. A touch screen, comprising:

a display device having a pixel array, comprising;

a plurality of data lines, arranged for driving the pixel array; and

a common electrode layer, having a plurality of openings, arranged for providing a common voltage to the pixel array; and

a touch sensing control circuit, coupled to the common electrode layer and a plurality of first data lines of the plurality of data lines, arranged for generating a first touch driving signal and applying the first touch driving signal to the plurality of first data lines; and

detecting a plurality of touch sensing signals respectively from a plurality of common electrodes of the common electrode layer when the first touch driving signal is applied to one of the first data lines wherein the openings are arranged for reducing a base capacitance induced between at least one of the common electrodes and at least one of data lines and the openings are aligned with a direction along which the first driving signal is transmitted in an area of touch sensing; and

the touch sensing control circuit further generates a second touch driving signal and applies the second touch driving signal to a plurality of second data lines of the data lines;

the polarity of the first touch driving signal is different from a polarity of the second touch driving signal such that the second touch driving signal applied to the data lines leads to reduction of the base capacitance.

2. The touch screen of claim 1, wherein the plurality of first sub-pixels includes a plurality of columns of first sub-pixels of a same color in the pixel array, and each of the first data lines corresponds to one of columns of the first sub-pixels, respectively.

3. The touch screen of claim 2, wherein the openings are above and aligned with each of columns of the first sub-pixels, respectively.

4. The touch screen of claim 1, wherein a magnitude of the first touch driving signal is different from a magnitude of the second touch driving signal.

5. The touch screen of claim 1, wherein a number of the plurality of first data lines that the first touch driving signal is applied to is different from a number of the plurality of second data lines that the second touch driving signal is applied to.

6. The touch screen of claim 1, wherein the plurality of first sub-pixels includes a plurality of columns of first sub-pixels of a first color in the pixel array, the plurality of second sub-pixels includes a plurality of columns of second sub-pixels of a second color in the pixel array;

each of the first data lines respectively corresponds to one of columns of the first sub-pixels, and each of the second data lines respectively corresponds to one of columns of the second sub-pixels.

7. The touch screen of claim 6, wherein the openings are above and aligned with each of columns of the second sub-pixels, respectively.

8. A touch sensing control circuit, comprising:

a signal generation circuit, coupled to a plurality of data lines of a display device, for generating a first touch driving signal, and applying the first touch driving to a plurality of first data lines of the data lines; and

a detection circuit, coupled a plurality of common electrodes of the display device, for detecting a plurality of touch sensing signals from the common electrodes when the first touch driving signal is applied to one of the first data lines;

wherein the common electrodes of the display device has a plurality of openings, and the openings are arranged for reducing a base capacitance induced between at least one of the common electrodes and at least one of data lines and the openings are aligned with a direction along which the first driving signal is transmitted in an area of touch sensing; and

the signal generation circuit further generates a second touch driving signal and applies the second touch driving signal to a plurality of second data lines of the data lines;

the polarity of the first touch driving signal is different from a polarity of the second touch driving signal such that the second touch driving signal applied to the data lines leads to reduction of the base capacitance.

9. The touch sensing control circuit of claim 8, wherein the plurality of first sub-pixels includes a plurality of columns of first sub-pixels of a same color in a pixel array of the display device, and each of the first data lines corresponds to one of columns of the first sub-pixels, respectively.

10. The touch sensing control circuit of claim 8, wherein a magnitude of the first touch driving signal is different from a magnitude of the second touch driving signal.

11. The touch sensing control circuit of claim 8, wherein a number of the plurality of first data lines that the first touch driving signal is applied to is different from a number of the plurality of second data lines that the second touch driving signal is applied to.

12. The touch sensing control circuit of claim 8, wherein the plurality of first sub-pixels includes a plurality of columns of first sub-pixels of a first color in the pixel array, and the plurality of second sub-pixels includes a plurality of columns of second sub-pixels of a second color in the pixel array;

each of the first data lines respectively corresponds to one of columns of the first sub-pixels, and each of the second data lines respectively corresponds to one of columns of the second sub-pixels.