DISPLAY APPARATUS

• US 20120262384A1
• Filed: 11/07/2011
• Published: 10/18/2012
• Est. Priority Date: 04/18/2011
• Status: Active Grant

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: KIM, HeeJoon, OH, Jae-Ho, CHO, Jaehyun
• Granted Patent: US 9,081,435 B2
• Time in Patent Office: Days
• US Class Current: 345/173
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• 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 3/042 by opto-electronic means

Abstract

In a display apparatus, one frame includes a first sub-frame in which a previous image is held and a second sub-frame in which a present image is displayed. A plurality of sensors recognizes an object disposed on a display panel and sequentially outputs sensing signals in response to scan signals. Sensing signals are divided into a first sensing signal read out during a first sub-frame and a second sensing signal read out during a second sub-frame, and a control circuit generates a noise free signal using the first and second sensing signals. Thus, a coordinate value indicating the position of the object may be generated based on the noise free signal, thereby preventing mis-operation or malfunction caused by the noise.

Claims

1. A display apparatus comprising:

a display panel comprising a plurality of pixels to display frames and sub frames, the frames comprising a previous frame, a present frame and a next frame, and the sub frames comprising a first sub frame and a second sub frame, wherein the pixels receive data voltages of the previous frame during the first sub-frame of the present frame to hold a previous image and to receive data voltages of the present frame during the second sub-frame of the present frame to display a present image;

a plurality of sensors configured to detect touch event on the display panel and to output sensing signals;

a scan driver comprising a plurality of stages to output a plurality of scan signals to switch the sensors, the scan driver configured to drive a first scan block among the output stages during the first sub-frame and to drive a second scan block among the stages during the second sub-frame;

a readout circuit configured to read out the output sensing signals; and

a control circuit configured to generate a noise free signal using a first sensing signal read out during the first sub-frame and a second sensing signal read out during the second sub-frame and to generate a coordinate value to indicate the position of the object on the display panel based on the noise free signal.

2. The display apparatus of claim 1, wherein the first sub-frame comprises successive first period and second period, the first scan block comprises first sub-scan block and second sub-scan block operated during the first period and the second period, respectively, the second sub-frame comprises successive third period and fourth period, and the second scan block comprises third sub-scan block and fourth sub-scan block operated during the third period and the fourth period, respectively.

3. The display apparatus of claim 2, wherein the first sub-scan block comprises (4p−

3)th stages among the stages, the second sub-scan block comprises (4p−

1)th stages among the stages, the third sub-scan block comprises (4p−

2)th stages among the stages, and the fourth sub-scan block comprises 4p-th stages, where the p is a natural number equal to or greater than 1.

4. The display apparatus of claim 3, wherein the display panel further comprises a plurality of scan lines to connect the sensors and the scan driver, each of the (4p−

3)th stages is connected to (8p−

7)th and (8p−

6)th scan lines, each of the (4p−

2)th stages is connected to (8p−

5)th and (8p−

4)th scan lines, each of the (4p−

1)th stages is connected to (8p−

3)th and (8p−

2)th scan lines, and each of the 4p-th stages is connected to (8p−

1)th and 8p-th scan lines.

5. The display apparatus of claim 3, wherein the scan driver is configured to receive first scan clock signal, second scan clock signal, third scan clock signal, and fourth scan clock signal, the (4p−

3)th stages are sequentially operated in response to the first scan clock signal, the (4p−

2)th stages are sequentially operated in response to the second scan clock signal, the (4p-1)th stages are sequentially operated in response to the third scan clock signal, and the 4p-th stages are sequentially operated in response to the fourth scan clock signal.

6. The display apparatus of claim 5, wherein the first scan clock signal, the second scan clock signal, the third scan clock signal, and the fourth scan clock signal are generated in an order of the first scan clock signal, the third scan clock signal, the second scan clock signal, and the fourth scan clock signal during an N-th frame, and the first scan clock signal, the second scan clock signal, the third scan clock signal, and the fourth scan clock signal are generated in an order of the third scan clock signal, the first scan clock signal, the fourth scan clock signal, and the second scan clock signal during an (N+1)th frame.

7. The display apparatus of claim 2, wherein the first sensing signal comprises a first sub-sensing signal read out during the first period and a second sub-sensing signal read out during the second period, and the second sensing signal comprises a third sub-sensing signal read out during the third period and a fourth sub-sensing signal read out during the fourth sub-sensing signal.

8. The display apparatus of claim 7, wherein the control circuit is configured to subtract the third sub-sensing signal from the first sub-sensing signal to generate a first difference value, to subtract the fourth sub-sensing signal from the second sub-sensing signal to generate a second difference value, and to generate the noise free signal using the first and second difference values.

9. The display apparatus of claim 8, wherein the control circuit is configured to calculate an average value of the first difference value and the second difference value, to subtract the average value from the third sub-sensing signal and the fourth sub-sensing signal to generate fifth sub-sensing signal and sixth sub-sensing signal, and to use the first sub-sensing signal, the second sub-sensing signal, the fifth sub-sensing signal, and the sixth sub-sensing signal as the noise free signal.

10. The display apparatus of claim 1, wherein the display panel comprises

a first substrate comprising a plurality of pixels arranged in a matrix shape;

and

a second substrate comprising a plurality of sensors arranged in a matrix shape to be coupled with the first substrate and facing the first substrate.

11. The display apparatus of claim 10, wherein the sensors comprise a plurality of first sensors to detect an infrared ray and a plurality of second sensors to detect a visible ray, and the first sensors are alternately arranged with the second sensors in a row or column direction.

12. The display apparatus of claim 11, further comprising:

a backlight unit comprising a plurality of first light sources to emit a white light and a plurality of second light sources to emit the infrared ray, wherein the first light sources and the second light sources are disposed at a rear side of the first substrate.

13. The display apparatus of claim 12, wherein the second light sources are grouped into a plurality of light emitting blocks, and the light emitting blocks are sequentially turned off at a time point at which the first sub-frame starts and sequentially turned on at a time point at which the second sub-frame starts.

14. The display apparatus of claim 13, wherein a continuation time duration of the turned-on period of each of the light emitting blocks is equal to a continuation time duration of the first sub-frame.

15. The display apparatus of claim 13, wherein the first sub-frame comprises successive first period and second period, the first scan block comprises first sub-scan block and second sub-scan block operated during the first period and the second period, respectively, the second sub-frame comprises successive third period and fourth period, and the second scan block comprises third sub-scan block and fourth sub-scan block operated during the third period and the fourth period, respectively.

16. The display apparatus of claim 15, wherein an output order of the first sub-sensing signal and the second sub-sensing signal is changed in every frame and an output order of the third sub-sensing signal and the fourth sub-sensing signal is changed in every frame.

17. The display apparatus of claim 16, wherein the first sensing signal comprises a first sub-sensing signal read out during the first period and a second sub-sensing signal read out during the second period, and the second sensing signal comprises a third sub-sensing signal read out during the third period and a fourth sub-sensing signal read out during the fourth sub-sensing signal.

18. The display apparatus of claim 17, wherein the control circuit is configured to subtract the first sub-sensing signal from the second sub-sensing signal to calculate a sensing value by an external light and to subtract the sensing value by the external light from the first sub-sensing signal and the second sub-sensing signal to generate the noise free signal.

19. The display apparatus of claim 1, further comprising:

a timing controller configured to receive an image data in synchronization with a first data enable signal and to output the image data in synchronization with a second data enable signal;

a data driver configured to receive the image data from the timing controller to output the data voltages to the display panel; and

a gate driver configured sequentially to output a gate voltage to the display panel.

20. The display apparatus of claim 19, wherein the second data enable signal is maintained in a low state during the first sub-frame and has a frequency two times faster than a frequency of the first data enable signal during the second sub-frame.

21. An apparatus comprising:

a panel comprising a pixel to display a frame comprising a first sub frame to hold previous frame and a second sub frame to display current frame, wherein a sensor is configured to sequentially output a series of sensing signals in response to detection of an object; and

a controller configured to generate a noise free signal using a first sensing signal read out during the first sub-frame and a second sensing signal read out during the second sub-frame.

22. The apparatus of claim 21, wherein the controller is configured to generate a coordinate value using the noise free signal.

23. A method comprising:

arranging a plurality of pixels to display a frame comprising a first sub frame to hold a previous frame and a second sub frame to display a current frame; and

generating a noise free signal using a first sensing signal read out during the first sub-frame and a second sensing signal read out during the second sub-frame, wherein a plurality of sensors are arranged to sequentially output a series of sensing signals in response to detection of an object.