TOUCH SENSING DEVICE

• US 20130050116A1
• Filed: 08/21/2012
• Published: 02/28/2013
• Est. Priority Date: 08/26/2011
• Status: Active Grant

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Display Co., Ltd.
• Inventors: HEO, Jonggu, SHIN, Myungho, LEE, Suwon, JANG, Yoonnara, KIM, Younggyu
• Granted Patent: US 9,069,425 B2
• Time in Patent Office: Days
• US Class Current: 345/173
• CPC Class Codes: G06F 2203/04104 Multi-touch detection in digitiser, i.e. details about the simultaneous detection of a plurality of touching locations, e.g. multiple fingers or pen and finger
• 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

Abstract

A touch sensing device includes a touch screen including Tx lines, Rx lines crossing the Tx lines, and touch sensors formed between the Tx lines and the Rx lines, and a touch screen driving circuit which senses all the touch sensors of the touch screen in a first sensing step to detect the presence or absence of a touch input, and then again senses the touch sensors, in which the touch input is detected as a first sensing result, in a second sensing step to detect a position of the touch input. When there is no touch sensor, in which the touch input is detected as the first sensing result, the touch screen driving circuit repeats the first sensing step.

Claims

1. A touch sensing device comprising:

a touch screen including Tx lines, Rx lines crossing the Tx lines, and touch sensors formed between the Tx lines and the Rx lines; and

a touch screen driving circuit which senses all the touch sensors of the touch screen in a first sensing step to detect the presence or absence of a touch input, and then again senses the touch sensors, in which the touch input is detected as a first sensing result, in a second sensing step to detect a position of the touch input,

wherein when there is no touch sensor, in which the touch input is detected as the first sensing result, the touch screen driving circuit repeats the first sensing step.

2. The touch sensing device of claim 1, wherein the touch screen driving circuit divides the touch screen into at least two Tx blocks,

wherein in the first sensing step, the touch screen driving circuit simultaneously supplies a driving signal to Tx lines of a first Tx block to simultaneously sense touch sensors of the first Tx block, and then simultaneously supplies the driving signal to Tx lines of a second Tx block to simultaneously sense touch sensors of the second Tx block,

wherein each of the first and second Tx blocks is divided along a long-axis direction of the Rx lines,

wherein each of the first and second Tx blocks includes at least two Tx lines and at least two Rx lines.

3. The touch sensing device of claim 2, wherein in the second sensing step, the touch screen driving circuit sequentially supplies the driving signal only to Tx lines present in a Tx block, in which the touch input is detected, to precisely sense touch sensors of the Tx block, in which the touch input is detected.

4. The touch sensing device of claim 3, wherein the touch screen driving circuit divides the touch screen into at least two Rx blocks,

wherein in the first sensing step, the touch screen driving circuit simultaneously or sequentially samples a voltage of touch sensors received through Rx lines of a first Rx block to convert the voltage of the touch sensors into touch raw data, and then simultaneously or sequentially samples a voltage of touch sensors received through Rx lines of a second Rx block to convert the voltage of the touch sensors into touch raw data,

wherein in the second sensing step, the touch screen driving circuit receives a voltage of touch sensors only through Rx lines of an Rx block, in which the touch input is detected, simultaneously or sequentially samples the voltage of the touch sensors, and converts the voltage of the touch sensors into touch raw data,

wherein each of the first and second Rx blocks is divided along a long-axis direction of the Tx lines,

wherein each of the first and second Rx blocks includes at least two Tx lines and at least two Rx lines.

5. The touch sensing device of claim 3, wherein the touch screen driving circuit stores the first sensing result obtained in the first sensing step in a memory,

wherein the touch screen driving circuit adds the first sensing result obtained in the first sensing step to a second sensing result obtained in the second sensing step and estimates the position of the touch input based on touch raw data produced as an addition result.

6. The touch sensing device of claim 5, wherein the touch screen driving circuit divides the touch screen into at least two Rx blocks,

wherein in the first sensing step, the touch screen driving circuit simultaneously or sequentially samples a voltage of touch sensors received through Rx lines of a first Rx block to convert the voltage of the touch sensors into touch raw data, and then simultaneously or sequentially samples a voltage of touch sensors received through Rx lines of a second Rx block to convert the voltage of the touch sensors into touch raw data,

wherein in the second sensing step, the touch screen driving circuit receives a voltage of touch sensors only through Rx lines of an Rx block, in which the touch input is detected, simultaneously or sequentially samples the voltage of the touch sensors, and converts the voltage of the touch sensors into touch raw data,

wherein each of the first and second Rx blocks is divided along a long-axis direction of the Tx lines,

wherein each of the first and second Rx blocks includes at least two Tx lines and at least two Rx lines.

7. The touch sensing device of claim 1, wherein in the first sensing step, the touch screen driving circuit sequentially supplies a driving signal to the Tx lines to sense the touch sensors,

wherein in the second sensing step, the touch screen driving circuit sequentially supplies the driving signal only to Tx lines in which the touch input is detected, to precisely sense touch sensors, in which the touch input is detected.

wherein the touch screen driving circuit stores the first sensing result obtained in the first sensing step in a memory,

wherein the touch screen driving circuit adds the first sensing result obtained in the first sensing step to a second sensing result obtained in the second sensing step and estimates the position of the touch input based on touch raw data produced as an addition result.

8. The touch sensing device of claim 7, wherein the touch screen driving circuit divides the touch screen into at least two Rx blocks,

wherein in the first sensing step, the touch screen driving circuit simultaneously or sequentially samples a voltage of touch sensors received through Rx lines of a first Rx block to convert the voltage of the touch sensors into touch raw data, and then simultaneously or sequentially samples a voltage of touch sensors received through Rx lines of a second Rx block to convert the voltage of the touch sensors into touch raw data,

wherein in the second sensing step, the touch screen driving circuit receives a voltage of touch sensors only through Rx lines of an Rx block, in which the touch input is detected, simultaneously or sequentially samples the voltage of the touch sensors, and converts the voltage of the touch sensors into touch raw data,

wherein each of the first and second Rx blocks is divided along a long-axis direction of the Tx lines,

wherein each of the first and second Rx blocks includes at least two Tx lines and at least two Rx lines.

9. The touch sensing device of claim 1, wherein the touch screen driving circuit includes:

a Tx driving circuit configured to supply a driving signal to the Tx lines;

an Rx driving circuit configured to sample a voltage of the touch sensors received through the Rx lines, convert the voltage of the touch sensors into touch raw data, and output the touch raw data,

a touch screen timing controller configured to synchronize an operation timing of the Tx driving circuit with an operation timing of the Rx driving circuit and control a channel setup of each of the Tx and Rx driving circuits, a sampling timing of the Rx driving circuit, and an analog-to-digital conversion timing of the Rx driving circuit; and

a touch recognition processor configured to compare the touch raw data with a predetermined threshold value and estimate touch raw data, which is equal to or greater than the threshold value, as touch input data.

10. The touch sensing device of claim 1, wherein the touch screen driving circuit divides the touch screen into at least two Tx blocks,

wherein the touch screen driving circuit repeatedly senses a voltage of the touch sensors two or more times while gradually reducing a size of the Tx block based on the position of the touch input obtained in the first sensing step.

11. The touch sensing device of claim 10, wherein the first sensing step includes:

a first block sensing step for sensing a voltage of touch sensors of at least two blocks divided from the touch screen and detecting the presence or absence of the touch input; and

a second block sensing step for dividing the block, in which the touch input is detected in the first block sensing step, into at least two sub-blocks and detecting the presence or absence of the touch input in the at least two sub-blocks, when the touch input is detected in the first block sensing step,

wherein in the first block sensing step, a driving signal is simultaneously applied to Tx lines of a first block, and then the driving signal is simultaneously applied to Tx lines of a second block,

wherein in the second block sensing step, the driving signal is simultaneously applied to Tx lines of a first sub-block divided in one of the first and second blocks, in which the touch input is detected, and then the driving signal is simultaneously applied to Tx lines of a second sub-block divided in one of the first and second blocks, in which the touch input is detected,

wherein a size of each of the at least two sub-blocks is less than a size of each of the at least two blocks.

12. The touch sensing device of claim 11, wherein the touch screen driving circuit proceeds to the second sensing step when the touch input is detected in the second block sensing step, sequentially supplies the driving signal only to Tx lines present in the sub-block, in which the touch input is detected in the second block sensing step, and precisely senses touch sensors of the sub-block, in which the touch input is detected.

13. The touch sensing device of claim 11, wherein when no touch input is detected in the first block sensing step, the touch screen driving circuit is disabled for a previously determined idle time and then repeats the first block sensing step,

wherein when no touch input is detected in the second block sensing step, the touch screen driving circuit repeats the first block sensing step.

14. The touch sensing device of claim 13, wherein the touch screen driving circuit proceeds to the second sensing step when the touch input is detected in the second block sensing step, sequentially supplies the driving signal only to Tx lines present in the sub-block, in which the touch input is detected in the second block sensing step, and precisely senses touch sensors of the sub-block, in which the touch input is detected.

15. The touch sensing device of claim 10, wherein the first sensing step includes:

a first block sensing step for sensing a voltage of touch sensors of at least two blocks divided from the touch screen and detecting the presence or absence of the touch input;

a second block sensing step for dividing the block, in which the touch input is detected in the first block sensing step, into at least two sub-blocks and detecting the presence or absence of the touch input in the at least two sub-blocks; and

a third block sensing step for dividing the sub-block, in which the touch input is detected in the second block sensing step, into at least two re-subdivided blocks and detecting the presence or absence of the touch input in the at least two re-subdivided blocks,

wherein in the first block sensing step, a driving signal is simultaneously applied to Tx lines of a first block, and then the driving signal is simultaneously applied to Tx lines of a second block,

wherein in the second block sensing step, the driving signal is simultaneously applied to Tx lines of a first sub-block divided in one of the first and second blocks, in which the touch input is detected, and then the driving signal is simultaneously applied to Tx lines of a second sub-block divided in one of the first and second blocks, in which the touch input is detected,

wherein in the third block sensing step, the driving signal is simultaneously applied to Tx lines of a first re-subdivided block of the at least two re-subdivided blocks, and then the driving signal is simultaneously applied to Tx lines of a second re-subdivided block of the at least two re-subdivided blocks,

wherein a size of each of the at least two sub-blocks is less than a size of each of the at least two blocks,

wherein a size of each of the at least two re-subdivided blocks is less than a size of each of the at least two sub-blocks.

16. The touch sensing device of claim 15, wherein the touch screen driving circuit proceeds to the second sensing step when the touch input is detected in the third block sensing step, sequentially supplies the driving signal only to Tx lines present in the re-subdivided block, in which the touch input is detected in the third block sensing step, and precisely senses touch sensors of the re-subdivided block, in which the touch input is detected.

17. The touch sensing device of claim 15, wherein when no touch input is detected in the first block sensing step, the touch screen driving circuit is disabled for a previously determined idle time and then repeats the first block sensing step,

wherein when no touch input is detected in the second block sensing step, the touch screen driving circuit repeats the first block sensing step.

18. The touch sensing device of claim 17, wherein the touch screen driving circuit proceeds to the second sensing step when the touch input is detected in the third block sensing step, sequentially supplies the driving signal only to Tx lines present in the re-subdivided block, in which the touch input is detected in the third block sensing step, and precisely senses touch sensors of the re-subdivided block, in which the touch input is detected.

19. The touch sensing device of claim 1, wherein the touch screen driving circuit divides the touch screen into blocks in a lattice pattern,

wherein in the first sensing step, the touch screen driving circuit simultaneously supplies a driving signal to Tx lines of a first Tx block of the touch screen to simultaneously sense touch sensors of the first Tx block, and then simultaneously supplies the driving signal to Tx lines of a second Tx block of the touch screen to simultaneously sense touch sensors of the second Tx block,

wherein each of the first and second Tx blocks is divided along a long-axis direction of the Rx lines,

wherein each of the first and second Tx blocks includes at least two Tx lines and at least two Rx lines,

wherein the first Tx block includes blocks belonging to a first group sharing the Tx lines of the first Tx block among the blocks of the lattice pattern,

wherein the second Tx block includes blocks belonging to a second group sharing the Tx lines of the second Tx block among the blocks of the lattice pattern.

20. The touch sensing device of claim 19, wherein the touch screen driving circuit precisely senses touch sensors of a partial sensing area greater than a block, in which the touch input is detected, in the second sensing step.

21. The touch sensing device of claim 20, wherein in the second sensing step, the touch screen driving circuit supplies the driving signal to Tx lines passing through the block, in which the touch input is detected, and supplies the driving signal to Tx lines crossing a block left or right adjacent to the block, in which the touch input is detected,

wherein the partial sensing area includes touch sensors of the block in which the touch input is detected, touch sensors of the block left or right adjacent to the block in which the touch input is detected, and some of touch sensors of blocks close to the block, in which the touch input is detected, and the block left or right adjacent to the block, in which the touch input is detected.

22. The touch sensing device of claim 20, wherein in the second sensing step, the touch screen driving circuit supplies the driving signal to Tx lines crossing the block, in which the touch input is detected, and supplies the driving signal to M Tx lines close to the block, in which the touch input is detected, in other blocks adjacent to the block, in which the touch input is detected, where M is a positive integer which is equal to or greater than 1 and less than the number of Tx lines included in one block,

wherein the partial sensing area includes touch sensors of the block in which the touch input is detected, and touch sensors connected to the M Tx lines.

23. The touch sensing device of claim 20, wherein in the second sensing step, the touch screen driving circuit supplies the driving signal to Tx lines passing through the block, in which the touch input is detected, and supplies the driving signal to Tx lines crossing a block upward or downward adjacent to the block, in which the touch input is detected,

wherein the partial sensing area includes touch sensors of the block in which the touch input is detected, touch sensors of the block upward or downward adjacent to the block in which the touch input is detected, and some of touch sensors of blocks close to the block, in which the touch input is detected, and the block upward or downward adjacent to the block, in which the touch input is detected.