Touch sensitive display device and driving apparatus and method thereof

• US 7,737,957 B2
• Filed: 09/21/2006
• Issued: 06/15/2010
• Est. Priority Date: 09/21/2005
• Status: Active Grant

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Lee, Joo-Hyung, Park, Jong-Woung, Uh, Kee-Han
• Primary Examiner(s): Liang; Regina
• Application Number:
  US11/533,910
• Publication Number:
  US 20070063991A1
• Time in Patent Office: 1,363 Days
• Field of Search: 345156-158, 345/168, 345/169, 345173-179, 345/211, 178/18.01, 178/18.03, 178 1805- 1807
• US Class Current: 345/173
• CPC Class Codes: G06F 1/3203 Power management, i.e. event-based initiation of a power-saving mode
• CPC Class Codes: G06F 1/3262 Power saving in digitizer or tablet
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• 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: G06F 3/0447 Position sensing using the local deformation of sensor cells
• CPC Class Codes: Y02D 30/50 in wire-line communication networks, e.g. low power modes or reduced link rate

Abstract

A display device includes a display panel, a plurality of pixels formed on the display panel, a plurality of sensing units formed on the display panel and generating sensor output signals in response to a touch exerted on the display panel, a sensing signal processor receiving and processing an analog sensor data signal originated from the sensor output signals to generate a digital sensor data signal, a first touch-determination unit detecting whether a touch exists based on the digital sensor data signal for a plurality of frames, and operating in a power saving mode, and a second touch-determination unit detecting whether and where a touch exists based on the digital sensor data signal for the plurality of frames, and operating in a normal mode. The display device includes hardwired logic units for detecting the touch, it detects the touch using the hardwired logic units in the power saving mode and converts the operation mode to the normal mode when the touch is detected, thus reducing power consumption.

Claims

1. A display device comprising:

a display panel;

a plurality of pixels formed on the display panel;

a plurality of sensing units formed on the display panel and generating sensor output signals in response to a touch exerted on the display panel;

a sensing signal processor receiving and processing an analog sensor data signal originated from the sensor output signals to generate a digital sensor data signal;

a first touch-determination unit detecting whether a touch exists based on the digital sensor data signal for a plurality of frames, and operating in a power saving mode; and

a second touch-determination unit detecting whether and where a touch exists based on the digital sensor data signal for the plurality of frames, and operating in a normal mode.

2. The display device of claim 1, wherein the first touch-determination unit comprises hardwired logic units.

3. The display device of claim 1, wherein the first touch-determination unit is cut off from a power in the normal mode.

4. The display device of claim 1, wherein the first touch-determination unit comprises:

an averaging unit averaging the digital sensor data signal for the plurality of frames;

a difference data generator generating a difference data based on the averaged digital sensor data signal; and

a comparator comparing the difference data with a reference data.

5. The display device of claim 4, wherein it is determined that a touch occurs when the difference data is equal to or greater than the reference data.

6. The display device of claim 1, wherein the second touch-determination unit comprises:

a first memory storing program codes;

a second memory storing the digital sensor data signal for the plurality of frames; and

a main processor operating based on the program codes read from the first memory, reading the digital sensor data signal for the plurality of frames from the second memory, and determining whether and where the touch exists based on the read digital sensor data signal.

7. The display device of claim 6, wherein the first memory and the main processor are cut off from a power in the power saving mode.

8. The display device of claim 1, wherein the sensing signal processor comprises:

an amplifier amplifying the analog sensor data signal; and

an analog-to-digital converter converting the amplified analog sensor data signal to generate the digital sensor data signal.

9. The display device of claim 8, wherein the amplifier has a plurality of channels and at least one of the channels is cut off from the power in the power saving mode.

10. The display device of claim 1, further comprising a frame memory storing the digital sensor data signal for a plurality of frames.

11. The display device of claim 1, wherein the sensing signal processor comprises the first touch-determination unit and is implemented in a single IC.

12. The display device of claim 1, wherein the second touch-determination unit comprises the first touch-determination unit and is implemented in a single IC.

13. The display device of claim 1, wherein the sensing signal processor and the first and second touch-determination units are implemented in a single IC.

14. An apparatus for driving a display device including a display panel and a plurality of sensing units generating sensor output signals in response to a touch exerted on the display panel, the apparatus comprising:

a sensing signal processor receiving and processing an analog sensor data signal originated from the sensor output signals to generate a digital sensor data signal;

a first touch-determination unit detecting whether a touch exists based on the digital sensor data signal for a plurality of frames and operating in a power saving mode; and

a second touch-determination unit detecting whether and where a touch exists based on the digital sensor data signal for the plurality of frames and operating in a normal mode.

15. The apparatus of claim 14, wherein the first touch-determination unit comprises hardwired logic units.

16. The apparatus of claim 14, wherein the first touch-determination unit is cut off from a power in the normal mode.

17. The apparatus of claim 14, wherein the first touch-determination unit comprises:

an averaging unit averaging the digital sensor data signal for the plurality of frames;

a difference data generator generating difference data based on the averaged digital sensor data signal; and

a comparator comparing the difference data with reference data.

18. The apparatus of claim 17 wherein it is determined that a touch occurs when the difference data is equal to or greater than the reference data.

19. The apparatus of claim 14, wherein the second touch-determination unit comprises:

a first memory storing program codes;

a second memory storing the digital sensor data signal for the plurality of frames; and

a main processor for operating based on the program codes read from the first memory, reading the digital sensor data signal for the plurality of frames from the second memory, and determining whether and where the touch exists based on the read digital sensor data signal.

20. The apparatus of claim 19, wherein the first memory and the main processor are cut off from a power in the power saving mode.

21. The apparatus of claim 14, wherein the sensing signal processor comprises:

an amplifier amplifying the analog sensor data signal; and

an analog-to-digital converter analog-to-digital converting the amplified analog sensor data signal to a digital sensor data to generate the digital sensor data signal.

22. The apparatus of claim 21, wherein the amplifier has a plurality of channels, and at least one of the channels is cut off from the power in the power saving mode.

23. The apparatus of claim 14, further comprising a frame memory saving the digital sensor data signal for a plurality of frames.

24. The apparatus of claim 14, wherein the sensing signal processor comprises the first touch-determination unit and is implemented in a single IC.

25. The apparatus of claim 14, wherein the second touch-determination unit comprises the first touch-determination unit and is implemented in a single IC.

26. The apparatus of claim 14, wherein the sensing signal processor and the first and second touch-determination units are implemented in a single IC.

27. A method of driving a display device including a display panel, a plurality of sensing units generating sensor output signals in response to a touch exerted on the display panel, and first and second touch-determination units determining the existence of a touch based on the sensor output signals, the method comprising:

generating a digital sensor data signal based on the sensor output signals;

determining whether a touch exists based on the digital sensor data signal in the first touch-determination unit;

cutting the first touch-determination unit off from a power and supplying the power to the second touch-determination unit when the first touch determination unit determines that a touch exists;

determining whether a touch exists based on the digital sensor data signal in the second touch-determination unit; and

supplying the power to the first touch-determination unit and cutting the second touch-determination unit off from the power after a predetermined time when the second touch determination unit determines that there is no touch.

28. The method of claim 27, wherein

the determination in the first and second touch determination units comprise:

averaging the digital sensor data signal for the plurality of frames;

generating a difference data based on the averaged digital sensor data signal;

comparing the difference data with a reference data; and

determining that a touch occurs when the difference data is equal to or greater than the reference data.

29. The method of claim 27, wherein the generation of the digital sensor data signal comprises:

amplifying the sensor output signals, and

analog-to-digital converting the amplified sensor output signals to generate the digital sensor data signal.

30. The method of claim 27, further comprising:

determining a position of a touch in the second touch-determination unit.