TOUCH POSITION DETECTING METHOD, TOUCH POSITION DETECTING DEVICE, AND FLAT PANEL DISPLAY

• US 20100212974A1
• Filed: 09/11/2009
• Published: 08/26/2010
• Est. Priority Date: 02/20/2009
• Status: Active Grant

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Display Co., Ltd.
• Inventors: KIM, Jinkyu
• Granted Patent: US 8,338,723 B2
• Time in Patent Office: Days
• US Class Current: 178/18.30
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/04182 Filtering of noise external to the device and not generated by digitiser components
• CPC Class Codes: G06F 3/04186 Touch location disambiguation
• CPC Class Codes: G06F 3/042 by opto-electronic means

Abstract

A method and a device for detecting a touch position and a flat panel display using the method and the device are disclosed. The touch position detecting method includes generating touch data from a touch sensor array; computing the touch data input in each of adjacent frames to generate difference data and then performing at least one binary operation and a filtering operation on the difference data to correct the difference data; determining an effective area and then calculating a first central coordinate and a second central coordinate; computing a reference vector between the first central coordinate and the second central coordinate, a position vector between a position coordinate and the second central coordinate, and an angle between the reference vector and the position vector; and determining the position coordinate on the touch boundary portion at the angle having a minimum value as a touch coordinate.

Claims

1. A touch position detecting method comprising:

generating touch data from a touch sensor array including a plurality of touch sensors;

computing the touch data input in each of adjacent frames to generate difference data and then performing at least one binary operation and a filtering operation on the difference data to correct the difference data so that only a touch boundary portion has a black gray level;

determining an effective area including outermost coordinates of the touch boundary portion in upward, downward, right and left directions and then calculating a first central coordinate according to a distribution density of black points in the touch boundary portion and a second central coordinate indicating the center of the effective area;

computing a reference vector between the first central coordinate and the second central coordinate, a position vector between a position coordinate on the touch boundary portion and the second central coordinate, and an angle between the reference vector and the position vector; and

determining the position coordinate on the touch boundary portion at the angle having a minimum value as a touch coordinate.

2. The touch position detecting method of claim 1, wherein the determining of the effective area comprises while the corrected difference data is simultaneously scanned in the upward, downward, right and left directions, recognizing a coordinate of a position firstly sensed in each of the upward, downward, right and left directions as the outermost coordinates of the touch boundary portion.

3. The touch position detecting method of claim 1, wherein the first central coordinate is positioned to be inclined to a portion, having a minimum radius of curvature, of the touch boundary portion based on the second central coordinate.

4. The touch position detecting method of claim 3, wherein the reference vector is obtained by subtracting the second central coordinate from the first central coordinate, wherein the position vector is obtained by subtracting the second central coordinate from the position coordinate on the touch boundary portion.

5. A touch position detecting device comprising:

a touch sensor array including a plurality of touch sensors;

a touch information processing unit that computes touch data input in each of adjacent frames to generate difference data and performs at least one binary operation and a filtering operation on the difference data to correct the difference data so that only a touch boundary portion has a black gray level;

an effective area determining unit that determines an effective area including outermost coordinates of the touch boundary portion in upward, downward, right and left directions and calculates a first central coordinate according to a distribution density of black points in the touch boundary portion and a second central coordinate indicating the center of the effective area;

a vector and angle calculating unit that computes a reference vector between the first central coordinate and the second central coordinate, a position vector between a position coordinate on the touch boundary portion and the second central coordinate, and an angle between the reference vector and the position vector; and

a touch coordinate detecting unit that determines the position coordinate on the touch boundary portion at the angle having a minimum value as a touch coordinate.

6. The touch position detecting device of claim 5, wherein the first central coordinate is positioned to be inclined to a portion, having a minimum radius of curvature, of the touch boundary portion based on the second central coordinate.

7. The touch position detecting device of claim 6, wherein the reference vector is obtained by subtracting the second central coordinate from the first central coordinate, wherein the position vector is obtained by subtracting the second central coordinate from the position coordinate on the touch boundary portion.

8. A flat panel display comprising:

a display device including a display panel, a data drive circuit driving data lines of the display panel, a scan drive circuit driving gate lines of the display panel, and a timing controller controlling operation timing of each of the data drive circuit and the scan drive circuit; and

a touch position detecting device including;

a touch sensor array including a plurality of touch sensors;

a touch information processing unit that computes touch data input in each of adjacent frames to generate difference data and performs at least one binary operation and a filtering operation on the difference data to correct the difference data so that only a touch boundary portion has a black gray level;

an effective area determining unit that determines an effective area including outermost coordinates of the touch boundary portion in upward, downward, right and left directions and calculates a first central coordinate according to a distribution density of black points in the touch boundary portion and a second central coordinate indicating the center of the effective area;

a vector and angle calculating unit that computes a reference vector between the first central coordinate and the second central coordinate, a position vector between a position coordinate on the touch boundary portion and the second central coordinate, and an angle between the reference vector and the position vector; and

a touch coordinate detecting unit that determines the position coordinate on the touch boundary portion at the angle having a minimum value as a touch coordinate.

9. The flat panel display of claim 8, wherein the first central coordinate is positioned to be inclined to a portion, having a minimum radius of curvature, of the touch boundary portion based on the second central coordinate.

10. The flat panel display of claim 9, wherein the reference vector is obtained by subtracting the second central coordinate from the first central coordinate, wherein the position vector is obtained by subtracting the second central coordinate from the position coordinate on the touch boundary portion.

11. The flat panel display of claim 8, wherein the plurality of touch sensors are formed inside a pixel array of the display panel.

12. The flat panel display of claim 8, wherein the plurality of touch sensors are stacked on an upper polarizing plate of the display panel or are interposed between the upper polarizing plate of the display panel and an upper glass substrate of the display panel.