Input sensing device and display device including the same
An input sensing device of a display device, which includes an input sensor including a transmit electrode and a receive electrode and a readout circuit that drives the input sensor. The readout circuit includes a phase adjustment circuit that outputs a phase adjustment signal corresponding to a delay characteristic of the transmit electrode and a transmitter that outputs a transmission signal, a phase of which is adjusted in response to the phase adjustment signal, to the transmit electrode.
1. An input sensing device, comprising:
an input sensor comprising a transmit electrode and a receive electrode; and
a readout circuit configured to drive the input sensor,
wherein the readout circuit includes:
a phase adjustment circuit configured to output a phase adjustment signal corresponding to a delay characteristic of the transmit electrode; and
a transmitter configured to output a transmission signal, a phase of which is adjusted in response to the phase adjustment signal, to the transmit electrode.
2. The input sensing device of claim 1 , wherein the transmission signal is a sine wave.
3. The input sensing device of claim 1 , wherein the readout circuit further comprises:
a receiver configured to receive a reception signal from the receive electrode and output a reception sensing signal.
4. The input sensing device of claim 3 , further comprising:
a transmission line electrically connecting the transmit electrode with the transmitter; and
a reception line electrically connecting the receive electrode with the receiver.
5. The input sensing device of claim 3 , wherein the phase adjustment circuit outputs the phase adjustment signal based on a phase difference between the transmission signal and the reception sensing signal.
6. The input sensing device of claim 3 , wherein the phase adjustment circuit comprises:
a phase shifter configured to shift a phase of the transmission signal and output a shifted transmission signal;
a first arithmetic operator circuit configured to perform an arithmetic operation on the reception sensing signal and the transmission signal;
a first filter configured to filter an output of the first arithmetic operator circuit and thereby output a first filtered signal;
a second arithmetic operator circuit configured to perform an arithmetic operation on the reception sensing signal and the shifted transmission signal;
a second filter configured to filter an output of the second arithmetic operator circuit and thereby output a second filtered signal; and
a phase calculator circuit configured to output the phase adjustment signal based on the first filtered signal and the second filtered signal.
7. The input sensing device of claim 6 , wherein each of the first filter and the second filter is a low pass filter.
8. The input sensing device of claim 1 , wherein the transmit electrode comprises a first transmit electrode and a second transmit electrode, and
wherein the transmitter outputs a first transmission signal corresponding to a first code to the first transmit electrode and outputs a second transmission signal corresponding to a second code different from the first code to the second transmit electrode.
9. The input sensing device of claim 8 , wherein the first transmission signal and the second transmission signal are offset in phase from one another.
10. The input sensing device of claim 9 , wherein the phase adjustment signal comprises a first phase adjustment signal and a second phase adjustment signal, and
wherein the transmitter outputs the first transmission signal, a phase of which is adjusted according to the first phase adjustment signal, to the first transmit electrode and outputs the second transmission signal, a phase of which is adjusted according to the second phase adjustment signal, to the second transmit electrode.
11. The input sensing device of claim 10 , wherein a first phase corresponding to the first phase adjustment signal is less than a phase difference between the first transmission signal and the second transmission signal, and
wherein a second phase corresponding to the second phase adjustment signal is less than the phase difference between the first transmission signal and the second transmission signal.
12. A display device, comprising:
a display panel;
an input sensor disposed on the display panel and comprising a transmit electrode and a receive electrode; and
a readout circuit configured to output a transmission signal to the transmit electrode and receive a reception signal from the receive electrode,
wherein the readout circuit comprises:
a phase adjustment circuit configured to output a phase adjustment signal corresponding to a delay characteristic of the transmit electrode; and
a transmitter configured to output the transmission signal, a phase of which is adjusted in response to the phase adjustment signal, to the transmit electrode.
13. The display device of claim 12 , wherein the readout circuit further comprises:
a receiver configured to receive the reception signal from the receive electrode and output a reception sensing signal based on the reception signal.
14. The display device of claim 13 , wherein the phase adjustment circuit outputs the phase adjustment signal based on a phase difference between the transmission signal and the reception sensing signal.
15. The display device of claim 13 , wherein the phase adjustment circuit comprises:
a phase shifter configured to shift a phase of the transmission signal and output a shifted transmission signal;
a first operator configured to perform an arithmetic operation on the reception sensing signal and the transmission signal;
a first filter configured to filter an output of the first operator and output a first filtered signal;
a second operator configured to perform an arithmetic operation on the reception sensing signal and the shifted transmission signal;
a second filter configured to filter an output of the second operator and output a second filtered signal; and
a phase calculator configured to output the phase adjustment signal based on the first filtered signal and the second filtered signal.
16. The display device of claim 15 , wherein each of the first filter and the second filter is a low pass filter.
17. The display device of claim 12 , wherein the transmit electrode comprises a first transmit electrode and a second transmit electrode, and
wherein the transmitter outputs a first transmission signal corresponding to a first code to the first transmit electrode and outputs a second transmission signal corresponding to a second code different from the first code to the second transmit electrode.
18. The display device of claim 17 , wherein the first transmission signal and the second transmission signal have different phases.
19. The display device of claim 18 , wherein the phase adjustment signal comprises a first phase adjustment signal and a second phase adjustment signal, and
wherein the transmitter outputs the first transmission signal, a phase of which is adjusted in response to the first phase adjustment signal, to the first transmit electrode and outputs the second transmission signal, a phase of which is adjusted in response to the second phase adjustment signal, to the second transmit electrode.
20. The display device of claim 19 , wherein a first phase corresponding to the first phase adjustment signal is less than a phase difference between the first transmission signal and the second transmission signal, and
wherein a second phase corresponding to the second phase adjustment signal is less than the phase difference between the first transmission signal and the second transmission signal.