DISPLAY APPARATUS

• US 20110115724A1
• Filed: 04/01/2010
• Published: 05/19/2011
• Est. Priority Date: 11/16/2009
• Status: Active Grant

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Inventors: NAM, Hyoung Sik, JEON, Jee-Hoon, OH, Jae-Ho
• Granted Patent: US 8,619,020 B2
• Time in Patent Office: Days
• US Class Current: 345/173
• CPC Class Codes: G06F 3/042 by opto-electronic means

Abstract

A display apparatus includes a display panel, a plurality of sensors, a read-out circuit, and a control circuit. The display panel includes a plurality of pixels receiving a data signal having a polarity reversed with respect to a common voltage to display an image. The sensors sense light to output sensing signals. The sensors may be integrated into the display panel. The read-out circuit is charged with the sensing signals generating charged signals in response to a sampling signal generated during a period in which the common voltage has a predetermined reference voltage level. The control circuit calculates a position on the display panel from the charged signals received signals from the read-out circuit.

Claims

1. A display apparatus comprising:

a display panel that includes a plurality of pixels receiving a data signal having a polarity reversed with respect to a common voltage to display an image;

a plurality of sensors that sense light and output at least one of a plurality of sensing signals;

a read-out circuit that is charged with the sensing signals to generate charged signals in response to a first sampling signal generated during a period in which the common voltage has a predetermined reference voltage level; and

a control circuit that receives the charged signals to calculate a position on the display panel based on the received signals.

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

a sensor driver that sequentially provides a scan signal to the sensors;

a timing controller that outputs a second sampling signal having a logic high state during a predetermined period after the scan signal is generated; and

a sampling signal generator that generates the first sampling signal based on the second sampling signal and a reference level period of the common voltage.

3. The display apparatus of claim 2, wherein the sampling signal generator comprises:

a first signal generator that generates a masking signal having a logic high state corresponding to the reference level period; and

a second signal generator that logically ANDs the masking signal with the second sampling signal to generate the first sampling signal.

4. The display apparatus of claim 3, wherein a high period of the masking signal has a width equal to or smaller than the reference level period of the common voltage.

5. The display apparatus of claim 3, further comprising a data driver that provides the data signal to the display panel in response to an output start signal, wherein the timing controller applies the output start signal to the data driver.

6. The display apparatus of claim 5, wherein the first signal generator comprises:

a counter that counts the output start signal from a falling time to a next rising time using a reference clock; and

a signal setter that outputs the masking signal in the logic high state during a period in which the count value is larger than a first reference value and smaller than a second reference value that is larger than the first reference value.

7. The display apparatus of claim 5, wherein the second signal generator comprises an AND gate that logically ANDs the masking signal with the second sampling signal to output the first sampling signal.

8. The display apparatus of claim 2, wherein the sensors are integrated into the display panel.

9. The display apparatus of claim 8, wherein the display panel further comprises:

a plurality of scan lines that sequentially receives the scan signal; and

a plurality of read-out lines that receives the sensing signals from the sensors.

10. The display apparatus of claim 9, wherein the read-out circuit comprises:

a plurality of operational amplifiers each receiving a corresponding sensing signal among the sensing signals from a corresponding read-out line among the read-out lines, comparing the corresponding sensing signal with a predetermined reference voltage, and increasing an output voltage thereof when the corresponding sensing signal is larger than the reference voltage;

a charging part comprising a plurality of capacitors respectively corresponding to the operational amplifiers to charge a corresponding output voltage;

a sampling part providing the output voltage to the charging part in response to the first sampling signal;

a read-out part sequentially outputting a voltage charged in each of the capacitors in response to switching signals; and

a shift register sequentially providing the switching signals to the read-out part.

11. The display apparatus of claim 1, wherein the data signal is inverted in an image frame unit.

12. The display apparatus of claim 1, further comprising a sensor driver that sequentially provides the scan signal to the sensors during an n-th sensing frame among a plurality of sensing frames and stops providing the scan signal during an (n+1)-th sensing frame among the sensing frames, where n is a positive integer equal to or greater than 1.

13. The display apparatus of claim 12, wherein the read-out circuit further comprises a normal signal generator that receives the sensing signals from the sensors during the n-th sensing frame, receives noise signals from the sensors during the (n+1)-th sensing frame, and subtracts the noises signals from the sensing signals to output normal sensing signals.

14. The display apparatus of claim 13, wherein the normal signal generator comprises:

a first frame memory;

a second frame memory;

a counter that counts the sensing frames to output a frame selection signal according to the count value;

a selector that stores the sensing signals received during the n-th sensing frame in the first frame memory in response to the frame selection signal and stores the noise signals received during the (n+1)-th sensing frame in the second frame memory in response to the frame selection signal; and

a subtractor that subtracts the noise signals from the sensing signals to output the normal sensing signals.

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

a data driver that reverses a polarity of the data signal with respect to the common voltage based on a polarity reversal signal; and

a timing controller that controls a period of the polarity reversal signal based on a selection signal.

16. The display apparatus of claim 15, wherein the selection signal is changed by an operation of a user, the polarity reversal signal is reversed at intervals of two or more image frame periods when the selection signal is in a logic high state, and the polarity reversal signal is reversed at one image frame period when the selection signal is in a logic low state.

17. A display apparatus comprising:

a display panel that includes a plurality of pixels to display an image;

a plurality of sensors that sense light to output first sensing signals;

a sensor driver that sequentially provides a scan signal to the sensors during an n-th sensing frame among a plurality of sensing frames and stops providing the scan signal during an (n+1)-th sensing frame among the sensing frames;

a normal signal generator that receives the first sensing signals from the sensors during the n-th sensing frame, receives noise signals from the sensors during the (n+1)-th sensing frame, and subtracts the noises signals from the first sensing signals to output second sensing signals; and

a control circuit that receives the second sensing signals to calculate a position on the display panel based on the second sensing signals, where n is a positive integer equal to or greater than 1.

18. The display apparatus of claim 17, wherein the normal signal generator comprises:

a first frame memory;

a second frame memory;

a counter that counts the sensing frames to output a frame selection signal according to the count value;

a selector that stores the first sensing signals in the first frame memory during the n-th sensing frame in response to the frame selection signal and stores the noise signals in the second frame memory during the (n+1)-th sensing frame in response to the frame selection signal; and

a subtractor that subtracts the noise signals from the first sensing signals to output the second sensing signals.

19. A display apparatus comprising:

a display panel that comprises a plurality of pixels each receiving a data signal to display an image;

a data driver that reverses a polarity of the data signal with respect to the common voltage based on a polarity reversal signal;

a timing controller that controls a period of the polarity reversal signal based on a selection signal;

a plurality of sensors that sense light to output sensing signals;

a read-out circuit that receives the sensing signals from the sensors; and

a control circuit that receives the sensing signals from the read-out circuit to calculate a position on the display panel based on the sensing signals.

20. The display apparatus of claim 19, wherein the selection signal is changed by an operation of a user, the polarity reversal signal is reversed at intervals of two or more image frame periods when the selection signal is in a logic high state, and the polarity reversal signal is reversed at one image frame period when the selection signal is in a logic low state.