Device and method for proximity sensing on an input device

1. A touch-sensitive display device, comprising:

a display panel;

a source line for providing a drive signal to the display panel;

a sensor electrode for obtaining a sensing signal for detection of an input object; and

an amplifier configured to:

compare the sensing signal to a reference voltage and output a comparison output; and

generate the drive signal based on amplifying a voltage corresponding to pixel data.

2. The device according to claim 1 , wherein the device further comprises an analog front end; and

wherein the comparison output comprises two comparison output signals supplied to the analog front end.

3. The device according to claim 2 , wherein the analog front end comprises a mixer; and

wherein the mixer and a differential input stage of the amplifier are configured to cooperatively operate as a current conveyer configured to generate differential current signals corresponding to the sensing signal.

4. The device according to claim 3 , wherein the analog front end further comprises an analog-to-digital converter configured to receive the differential current signals and generate digital detection data.

5. The device according to claim 4 , further comprising:

a controller configured to receive the digital detection data and process the digital detection data to generate positional information of the input object.

6. The device according to claim 1 , wherein the amplifier is electrically connectable to the source line via a multiplexer.

7. The device according to claim 1 , wherein the amplifier further comprises:

a differential input stage; and

an output stage;

wherein the comparison output is output from the differential input stage; and

wherein the drive signal is output from the output stage.

8. The device according to claim 7 , wherein the differential input stage includes a first input and a second input;

wherein the first input of the differential input stage is configured to receive an output of the amplifier during a display operation and to receive the sensing signal during a sensing operation; and

wherein the second input of the differential input stage is configured to receive the voltage corresponding to pixel data during the display operation and to receive the reference voltage during the sensing operation.

9. The device according to claim 8 , wherein the output stage is configured to place the output of the amplifier into a high impedance state during the sensing operation to stop operation of the output stage during the sensing operation.

10. A processing system for a touch-sensitive display device, comprising:

a first amplifier configured to:

compare a first sensing signal from a sensor electrode to a reference voltage and output a first comparison output; and

generate a first drive signal to be supplied to a display panel via a source line based on amplifying a voltage corresponding to first pixel data;

a second amplifier configured to:

compare a second sensing signal from the sensor electrode to the reference voltage and output a second comparison output; and

generate a second drive signal to be supplied to the display panel via the source line based on amplifying a voltage corresponding to second pixel data; and

a first interface electrically connectable to the source line to provide the first drive signal to the source line and electrically connectable to the sensor electrode to provide the first sensing signal to the first amplifier; and

a second interface electrically connectable to the source line to provide the second drive signal to the source line and electrically connectable to the sensor electrode to provide the second sensing signal to the second amplifier.

11. The processing system according to claim 10 , further comprising:

a common analog front end shared by the first and second amplifiers;

wherein the first amplifier and the second amplifier are configured to supply the first comparison output and the second comparison output, respectively, to the common analog front end.

12. The processing system according to claim 10 , further comprising:

a common voltage source configured to supply a common voltage, wherein the first interface or the second interface is configured to electrically connect the common voltage source to the sensor electrode while the sensor electrode is being used as a common voltage electrode for the display panel.

13. The processing system according to claim 10 , wherein the first amplifier is connectable to the sensor electrode for sensing operation while the second amplifier is connected to the source line for display operation.

14. The processing system according to claim 13 , wherein the second amplifier is connectable to the sensor electrode for sensing operation while the first amplifier is connected to the source line for display operation.

15. A processing system for a touch-sensitive display device, comprising:

a plurality of amplifiers, wherein each amplifier of the plurality of amplifiers is configured to:

compare a respective sensing signal from a respective sensor electrode to a reference voltage and output a respective comparison output; and

generate a respective drive signal to be supplied to a display panel via a respective source line based on amplifying a respective voltage corresponding to respective pixel data; and

a plurality of interfaces, wherein each respective interface of the plurality of interfaces is electrically connectable to a respective source line to provide a respective drive signal to the source line and electrically connectable to a respective sensor electrode to provide a respective sensing signal to a respective amplifier.

16. The processing system according to claim 15 , wherein the plurality of amplifiers comprises:

a first amplifier configured to:

compare a first sensing signal from a first sensor electrode to the reference voltage and output a first comparison output; and

generate a first drive signal to be supplied to the display panel via a first source line based on amplifying a voltage corresponding to first pixel data; and

a second amplifier configured to:

compare a second sensing signal from a second sensor electrode to the reference voltage and output a second comparison output; and

generate a second drive signal to be supplied to the display panel via a second source line based on amplifying a voltage corresponding to second pixel data; and

wherein the plurality of interfaces comprises:

a first interface electrically connectable to the first source line to provide the first drive signal to the first source line and electrically connectable to the first sensor electrode to provide the first sensing signal to the first amplifier; and

a second interface electrically connectable to the second source line to provide the second drive signal to the second source line and electrically connectable to the second sensor electrode to provide the second sensing signal to the second amplifier.

17. The processing system according to claim 16 , wherein the plurality of amplifiers further comprises:

a third amplifier configured to:

compare a third sensing signal from a third sensor electrode to the reference voltage and output a third comparison output; and

generate a third drive signal to be supplied to the display panel via a third source line based on amplifying a voltage corresponding to third pixel data; and

a fourth amplifier configured to:

compare a fourth sensing signal from a fourth sensor electrode to the reference voltage and output a fourth comparison output; and

generate a fourth drive signal to be supplied to the display panel via a fourth source line based on amplifying a voltage corresponding to fourth pixel data; and

wherein the plurality of interfaces further comprises:

a third interface electrically connectable to the third source line to provide the third drive signal to the third source line and electrically connectable to the third sensor electrode to provide the third sensing signal to the third amplifier; and

a fourth interface electrically connectable to the fourth source line to provide the fourth drive signal to the fourth source line and electrically connectable to the fourth sensor electrode to provide the fourth sensing signal to the fourth amplifier.

18. The processing system according to claim 17 , further comprising:

an analog front end;

wherein the first amplifier, the second amplifier, the third amplifier and the fourth amplifier are configured to supply the first comparison output, the second comparison output, the third comparison output and the fourth comparison output, respectively, to the common analog front end.

19. The processing system according to claim 18 , wherein the common analog front end is configured to receive only one of the first, second, third or fourth comparison outputs at a time; and

wherein at least two of the plurality of amplifiers are configured to be simultaneously connected to respective source lines.

20. The processing system according to claim 17 , further comprising:

a common voltage source configured to supply a common voltage, wherein the first interface, the second interface, the third interface or the fourth interface is configured to electrically connect the common voltage source to the first sensor electrode, the second sensor electrode, the third sensor electrode or the fourth sensor electrode while the first sensor electrode, the second sensor electrode, the third sensor electrode or the fourth sensor electrode is being used as a common voltage electrode for the display panel.