Display panel with touch detection function, method of driving the same, driving circuit, and electronic unit
A display panel with a touch detection function, in which display operation is less affected by touch detection operation, a method of driving the display panel with a touch detection function, a driving circuit, and an electronic unit having the display panel with a touch detection function are disclosed. The display panel with a touch detection function includes: one or more display elements; one or more drive electrodes; one or more touch detection electrodes; and a drive section selectively applying a DC drive signal or an AC drive signal to the drive electrodes.
1. A driving circuit for an FFS display panel having a plurality of pixel electrodes and a plurality of common electrodes, the driving circuit comprising
an output wiring configured to selectively output a first drive signal or a second drive signal for driving at least one of the common electrodes,
wherein
the output wiring outputs:
the first drive signal for driving at least one of the common electrodes in order to perform a display operation on the display panel for display during a first period; and
the second drive signal for driving at least one of the common electrodes in order to perform a touch detection in a second period other than the first period, the second drive signal being different from the first drive signal and having a pulse waveform that transitions from a first voltage to a second voltage.
2. The driving circuit according to claim 1 , wherein
the first drive signal is a DC signal,
the second drive signal is an AC signal,
the first period is a display period, and
the second period is a touch detection period.
3. The driving circuit according to claim 2 , wherein
the driving circuit drives at least one common electrode in the touch detection period.
4. The driving circuit according to claim 3 , wherein
the driving circuit drives the common electrodes in the touch detection period.
5. The driving circuit according to claim 1 , wherein
the output wiring is configured to:
sequentially select at least one of the common electrodes each extending in a predetermined direction, as a drive object electrode; and
drive the drive object electrode for touch detection while applying the first drive signal to at least one of the common electrodes other than the drive object electrode, and
the touch detector comprises a touch detection section that detects a touch event based on signals output from the drive object electrodes.
6. The driving circuit according to claim 1 , further comprising a switch element to apply:
the first drive signal to at least one of the common electrodes in the first period; and
the second drive signal to at least one of the common electrodes in the second period.
7. The driving circuit according to claim 1 , further comprising an AC-drive-signal wire and a DC-drive-signal wire, wherein
the driving circuit is configured to output:
the second drive signal supplied from the AC-drive-signal wire; and
the first drive signal supplied from the DC-drive-signal wire.
8. The driving circuit according to claim 1 , further comprising a first DC-drive-signal wire and a second DC-drive-signal wire, and
the driving circuit is configured to output:
the second drive signal that is a signal alternately supplied from the first DC-drive-signal wire and the second DC-drive-signal wire; and
the first drive signal that is either a first DC drive signal from the first DC-drive-signal wire or a second DC drive signal from the second DC-drive-signal wire.
9. The driving circuit according to claim 8 , wherein the driving circuit is configured to output the second DC drive signal supplied from the second DC-drive-signal wire, the second DC drive signal being lower than the first DC drive signal supplied from the first DC-drive-signal wire.
10. The driving circuit according to claim 7 , wherein the second drive signal supplied to the AC-drive-signal wire is a signal generated by allowing a buffer circuit to alternately switch
a first power source to output a first DC voltage and
a second power source to output a second DC voltage that is lower than the first DC voltage.
11. The driving circuit according to claim 8 , wherein
a first DC drive voltage supplied to the first DC-drive-signal wire is supplied from the first power source,
a second DC drive voltage supplied to the second DC-drive-signal wire is supplied from the second power source, and
the second DC voltage is lower than the first DC voltage.
12. An IC chip for an FFS display panel having a plurality of pixel electrodes and a plurality of common electrodes, the IC chip comprising
an output wiring that selectively outputs a first signal or a second signal for driving at least one of the common electrodes,
wherein
the output wiring outputs:
the first signal for driving at least one of the common electrodes in order to perform a display operation on the display panel for display during a first period; and
the second signal for driving at least one of the common electrodes in order to perform a touch detection in a second period other than the first period, the second drive signal being different from the first drive signal and having a pulse waveform that transitions from a first voltage to a second voltage.
13. The IC chip according to claim 12 , wherein
the first drive signal is a DC signal,
the second drive signal is an AC signal,
the first period is a display period, and
the second period is a touch detection period.
14. The IC chip according to claim 13 , wherein
the IC chip drives at least one common electrode in the touch detection period.
15. The IC chip according to claim 14 , wherein
the IC chip drives the common electrodes in the touch detection period.
16. The IC chip according to claim 12 , wherein
the output wiring is configured to:
sequentially select at least one of the common electrodes each extending in a predetermined direction, as a drive object electrode; and
drive the drive object electrode for touch detection while applying the first drive signal to at least one of the common electrodes other than the drive object electrode, and
the touch detector comprises a touch detection section detects a touch event based on signals output from the drive object electrodes.
17. The IC chip according to claim 12 , further comprising a switch element to apply:
the first drive signal to at least one of the common electrodes in the first period; and
the second drive signal to at least one of the common electrodes in the second period.
18. The IC chip according to claim 12 , further comprising an AC-drive-signal wire and a DC-drive-signal wire, wherein
the IC chip is configured to output:
the second drive signal supplied from the AC-drive-signal wire; and
the first drive signal supplied from the DC-drive-signal wire.
19. The IC chip according to claim 12 , further comprising a first DC-drive-signal wire and a second DC-drive-signal wire, and
the IC chip is configured to output:
the second drive signal that is a signal alternately supplied from the first DC-drive-signal wire and the second DC-drive-signal wire; and
the first drive signal that is either a first DC drive signal from the first DC-drive-signal wire or a second DC drive signal from the second DC-drive-signal wire.
20. The IC chip according to claim 19 , wherein the IC chip is configured to output the second DC drive signal supplied from the second DC-drive-signal wire, the second DC drive signal being lower than the first DC drive signal supplied from the first DC-drive-signal wire.
21. The IC chip according to claim 18 , wherein the second drive signal supplied to the AC-drive-signal wire is a signal generated by allowing a buffer circuit to alternately switch
a first power source to output a first DC voltage and
a second power source to output a second DC voltage that is lower than the first DC voltage.