DISPLAY DEVICE AND METHOD OF DRIVING THE SAME

• US 20080218489A1
• Filed: 10/30/2007
• Published: 09/11/2008
• Est. Priority Date: 03/07/2007
• Status: Active Grant

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Inventors: Lee, Joo-Hyung, PARK, Jong-Woung, CHO, Man-Seung, UH, Kee-Han, CHA, Young-Ok, KIM, Hyung-Guel
• Granted Patent: US 8,736,556 B2
• Time in Patent Office: Days
• US Class Current: 345/173
• CPC Class Codes: G06F 3/0416 Control or interface arrangements specially adapted for digitisers
• 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 3/0447 Position sensing using the local deformation of sensor cells

Abstract

A method of driving a display device having a plurality of pixels, a plurality of sensing units, and a plurality of sense data lines to which the plurality of sensing units are connected, includes: reading sense signals from the sense data lines; determining whether or not the display has been touched and the number of touches, generating X-axis and Y-axis position data based on the sense signals, and determining, when the quantity of touches is plural, whether a plurality of touches are sequentially generated, and the touch position of each.

Claims

1. A method of driving a display device comprising a plurality of pixels, a plurality of sensing units, and a plurality of sense data lines to which the plurality of sensing units are connected, comprising:

reading sense signals from the sense data lines;

determining from the sense signals whether or not the display has been touched;

determining from the sense signals the number of touches, and generating X-axis and Y-axis position data based on the sense signals; and

,

when a plural number of touches have occurred, determining whether the plurality of touches are sequentially generated and a touch position thereof based on the X-axis and Y-axis position data.

2. The method of claim 1, wherein the determining of a touch position comprises:

determining whether a plurality of X-axis position data exist; and

when the plurality of X-axis position data do not exist and a plurality of Y-axis position data do exist, setting X-axis position data of an immediately previous touch as the X-axis position data of the current touch, and setting Y-axis position data having a different value from Y-axis position data of the previous touch as the Y-axis position data of the current touch.

3. The method of claim 2, wherein the determining of a touch position further comprises:

when the plurality of X-axis position data exist, determining whether the plurality of Y-axis position data exist; and

when the plurality of Y-axis position data do not exist, setting the Y-axis position data of the immediately previous touch as the Y-axis position data of the current touch, and setting X-axis position data having a different value from the X-axis position data of the previous touch as the X-axis position data of the current touch.

4. The method of claim 3, wherein the determining of a touch position further comprises

when a plurality of Y-axis position data exist, setting the X-axis and Y-axis position data having different values from the X-axis and Y-axis position data of the previous touch as the X-axis and Y-axis position data of the current touch.

5. The method of claim 4, wherein the determining of a touch position further comprises when the number of touches is “

1,”

setting the X-axis and Y-axis position data as the X-axis and Y-axis position data of the current touch.

6. The method of claim 5, wherein the determining of a touch position further comprises when the quantity of touches is “

1”

, changing a flag value.

7. The method of claim 6, wherein the determining of a touch position further comprises determining whether a plurality of touches are sequentially occurred based on the flag value.

8. The method of claim 7, further comprising initializing a flag value after X-axis and Y-axis position data of the current touch are set.

9. The method of claim 7, wherein the plurality of touches occur one by one in each frame.

10. The method of claim 1, wherein the number of the touches is “

2.”

11. A display device comprising:

a display panel having a plurality of pixels;

a plurality of first sense signal lines extending in a first direction in the display panel and transferring first sense signals;

a plurality of second sense signal lines extending in a second direction in the display panel and transferring second sense signals;

a plurality of first sensing units that are connected to the first sense signal lines and that generate the first sense signals according to a touch with the display panel;

a plurality of second sensing units that are connected to the second sense signal lines and that generate the second sense signals according to the touch with the display panel; and

a touch determination unit for determining the touch or not and the quantity of touches, and generating X-axis and Y-axis position data of the touch based on the first sense signals and the second sense signals that are transferred through the first sense signal lines and the second sense signal lines, respectively, and determining, when the quantity of touches is plural, whether a plurality of touches are sequentially occurred, and the touch position based on the X-axis and Y-axis position data.

12. The display device of claim 11, wherein the touch determination unit determines, when a plurality of touches are sequentially occurred, whether a plurality of X-axis position data exist, determines, when a plurality of X-axis position data do not exist, that a plurality of Y-axis position data exist, sets X-axis position data of an immediately previous touch as X-axis position data of the current touch, and sets Y-axis position data having a different value from Y-axis position data of the previous touch among first and second Y-axis position data as Y-axis position data of the current touch.

13. The display device of claim 12, wherein the touch determination unit determines, when a plurality of X-axis position data exist, whether a plurality of Y-axis position data exist, sets, when a plurality of Y-axis position data do not exist, Y-axis position data of the immediately previous touch as Y-axis position data of the current touch, and sets X-axis position data having a different value from X-axis position data of the previous touch among first and second X-axis position data as X-axis position data of the current touch.

14. The display device of claim 13, wherein the touch determination unit determines, when a plurality of X-axis position data exist, whether a plurality of Y-axis position data exist, sets, when a plurality of Y-axis position data exist, X-axis and Y-axis position data having a different value from X-axis and Y-axis position data of the previous touch among the plurality of X-axis and Y-axis position data as X-axis and Y-axis position data of the current touch.

15. The display device of claim 14, wherein the touch determination unit sets, when the quantity of touches is “

1,”

the X-axis and Y-axis position data as X-axis and Y-axis position data of the current touch.

16. The display device of claim 11, wherein the touch determination unit comprises a register in which values of a plurality of flags are stored.

17. The display device of claim 16, wherein the flags comprises a sequential touch flag, and the touch determination unit activates, when the quantity of touches is “

1,”

the sequential touch flag.

18. The display device of claim 17, wherein the flags further comprises first and second touch flags, and the touch determination unit sets, when the touch is generated, values of the first touch flag and the second touch flag according to the quantity of touches.

19. The display device of claim 18, wherein the flags further comprises first and second position information flags, and the touch determination unit sets values of the first position information flag and the second position information flag according to whether the plurality of X-axis position data or the plurality of Y-axis position data exist.

20. The display device of claim 16, wherein the touch determination unit further comprises a touch state determination unit for determining the touch or not and the quantity of touches, and generating the X-axis position data and Y-axis position data, and a controller for determining the touch position.

21. The display device of claim 20, wherein the touch determination unit further comprises a touch generation signal generator and a touch information output unit, and the touch generation signal generator generates and outputs a touch generation signal of the corresponding state according to the touch or not, and the touch information output unit outputs X-axis and Y-axis position data of the current touch.

22. The display device of claim 11, wherein the sensing unit comprises:

a variable capacitor that has liquid crystal as a dielectric and that has capacitance that changes according to a pressure; and

a reference condenser that is connected in series to the variable condenser.