IN-CELL TOUCH SCREEN AND DRIVE METHOD THEREOF

• US 20140204055A1
• Filed: 12/18/2013
• Published: 07/24/2014
• Est. Priority Date: 01/23/2013
• Status: Active Grant

• Current Assignee: Shanghai Tianma Micro-Electronics Company Limited (Tianma Microelectronics Company Limited)
• Original Assignee: Shanghai Tianma Micro-Electronics Company Limited (Tianma Microelectronics Company Limited)
• Inventors: LU, Feng, Ma, Jun
• Granted Patent: US 9,223,452 B2
• Time in Patent Office: Days
• US Class Current: 345/174
• 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 3/0418 for error correction or compensation, e.g. based on parallax, calibration or alignment
• 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
• CPC Class Codes: G06F 3/0445 using two or more layers of sensing electrodes, e.g. using two layers of electrodes separated by a dielectric layer
• 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: G09G 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence

Abstract

An In-cell touch screen and a method for driving the same includes: concurrently providing a plurality of gate drive signals to the plurality of gate lines line by line and a plurality of touch drive signals to the plurality of drive lines line by line, collecting original touch signals from the plurality of sensing lines line by line; when collecting is performed on a sensing line and any gate line covered by the sensing line is supplied with a gate drive signal, defining the original touch signals collected from a sensing line as interference signals; and removing the interference signals from the original touch signals to obtain a valid touch signal.

Claims

1. A method for driving an In-cell touch screen, wherein the In-cell touch screen comprises an array substrate and a color film substrate disposed opposite to each other, the color film substrate comprises a plurality of drive lines and a plurality of sensing lines intersecting with the plurality of drive lines in an insulating way, the array substrate comprises a plurality of gate lines and a plurality of data lines intersecting with the plurality of gate lines in an insulating way, each of the sensing lines is parallel to the gate lines and covers multiple gate lines, the method comprising:

concurrently providing a plurality of gate drive signals to the plurality of gate lines line by line and a plurality of touch drive signals to the plurality of drive lines line by line;

collecting original touch signals from the plurality of sensing lines line by line;

wherein collecting is performed on a sensing line and any of the gate lines covered by the sensing line is supplied with a gate drive signal;

defining the original touch signals collected from the sensing line as interference signals; and

removing the interference signals from the original touch signals to obtain a valid touch signal.

2. The method according to claim 1, wherein the color film substrate comprises:

a transparent substrate, wherein the plurality of drive lines and the plurality of sensing lines are formed on the transparent substrate, each of the plurality of sensing lines is divided into a plurality of segments by the plurality of drive lines;

an color-resist insulating layer on the plurality of drive lines and the plurality of sensing lines, wherein the color-resist insulating layer comprises a plurality of via holes; and

a metal bridging layer formed on the color-resist insulating layer, wherein the segments of the plurality of sensing lines are connected through the via holes by the metal bridging layer.

3. The method according to claim 2, wherein the color film substrate further comprises a black matrix layer formed between the transparent substrate and the plurality of drive lines and sensing lines.

4. The method according to claim 3, wherein the plurality of drive lines and the plurality of sensing lines comprise a latticed metal layer respectively, and the latticed metal layers are covered by the black matrix layer.

5. The method according to claim 1, wherein after removing the interference signals from the original touch signals, an average of remaining original touch signals collected from each sensing line is taken as a valid touch signal of the sensing line.

6. The method according to claim 1, wherein a number n of touch scans on the drive lines and sensing lines are accomplished in a number m of display scanning periods T for all the gate lines, where m and n are integers greater than or equal to 1.

7. The method according to claim 6, wherein m equals to 1 and n is greater than 1.

8. The method according to claim 7, wherein n is in a range between 3 and 5.

9. The method according to claim 7, wherein a preset beginning time t1 and a preset finishing time t2 are set for each sensing line in one display scanning period T, and the original touch signals collected by the sensing line from the preset beginning time t1 to the preset finishing time t2 are defined as the interference signals.

10. The method according to claim 9, wherein a number of the gate lines is defined as x, a number of the sensing lines is defined as y, one of the y sensing lines is spaced from a first gate line of the display scan by g gate lines, and the one sensing line covers s gate lines, where x, y, g and s are integers greater than or equal to 1 and x is greater than or equal to y, and the preset beginning time t1 and the preset finishing time t2 are calculated from the following formulas:

t1=(g+1)×

T/x

t2=(g+1+s)×

T/x;

wherein s is in a range between 50 and 70.

11. An In-cell touch screen, comprising an array substrate, a color film substrate disposed opposite to the array substrate, and a drive device, wherein the color film substrate comprises a plurality of drive lines and a plurality of sensing lines intersecting with each other and insulated from each other;

the array substrate comprises a plurality of gate lines and a plurality of data lines intersecting with each other and insulated from each other, each of the sensing lines is parallel to the gate lines and covers multiple gate lines;

the drive device comprises a display drive circuit and a touch drive circuit, the display drive circuit provides gate drive signals to the plurality of gate lines line by line, at the same time, the touch drive circuit provides touch drive signals to the plurality of drive lines line by line, and original touch signals are collected from the plurality of sensing lines line by line;

when collecting is performed on the sensing line and any of the gate lines covered by the sensing line is supplied with a gate drive signal, the original touch signals collected from one sensing line are defined as interference signals; and

the touch drive circuit removes the interference signals from the original touch signals to obtain valid touch signals.

12. The In-cell touch screen according to claim 11, wherein the color film substrate comprises:

a transparent substrate, wherein the plurality of drive lines and the plurality of sensing lines are formed on the transparent substrate, each of the plurality of sensing lines is divided into segments by the plurality of drive lines;

an color-resist insulating layer laid on the plurality of drive lines and the plurality of sensing lines, wherein the color-resist insulating layer comprises a plurality of via holes; and

a metal bridging layer formed on the color-resist insulating layer, wherein the segments of the plurality of sensing lines are connected through the via holes by the metal bridging layer.

13. The In-cell touch screen according to claim 12, wherein the color film substrate further comprises a black matrix layer formed between the transparent substrate and the plurality of drive lines and sensing lines.

14. The In-cell touch screen according to claim 13, wherein the plurality of drive lines and the plurality of sensing lines comprise a latticed metal layer respectively, and the latticed layers are covered by the black matrix layer.

15. The In-cell touch screen according to claim 11, wherein the touch drive circuit takes an average of remaining original touch signals collected from each sensing line as a valid touch signal of the sensing line after removing the interference signals from the original touch signals.

16. The In-cell touch screen according to claim 11, wherein n touch scans on all the drive lines and sensing lines are accomplished in m display scanning periods for all the gate lines, where m and n are integers greater than or equal to 1.

17. The In-cell touch screen according to claim 16, wherein m equals to 1 and n is greater than 1.

18. The In-cell touch screen according to claim 17, wherein n is in a range between 3 and 5.

19. The In-cell touch screen according to claim 18, wherein a preset beginning time t1 and a preset finishing time t2 are set for each sensing line in one display scanning period T, and the original touch signals collected from the preset beginning time t1 to the preset finishing time t2 by the sensing line are defined as the interference signals.

20. The In-cell touch screen according to claim 19, wherein a number of the gate lines is defined as x, the number of the sensing lines is defined as y, one of the y sensing lines is spaced from the first gate line of the display scan by g gate lines, and the one sensing line covers gate lines, where x, y, g and s are integers greater than or equal to 1 and x is greater than or equal to y, the preset beginning time t1 and the preset finishing time t2 are calculated from the following formulas:

t1=(g+1)×

T/x

t2=(g+1+s)×

T/x;

wherein s is in a range between 50 and 70.