Display device and electronic apparatus
View Patent ↗A display device of the invention includes a display panel 10 and a touch panel 22 . A detector circuit 50 has switches 411 and 412 . Switches 411 and 412 are alternately turned on and off repeatedly in the setting period. Touch detection is performed during a counting period that follows the setting period on the basis of required time until a voltage at the node reaches a reference voltage while the switch 411 is turned off and switch 412 is turned on. Common voltage changes in the setting period while switch 411 is turned off and switch 412 is turned on.
1. A display device comprising:
a display panel including a plurality of pixels each having a gray scale according to the difference voltage between a voltage applied to an associated pixel electrode and a voltage applied to a common electrode, the common electrode facing the pixel electrodes;
a driver circuit that supplies data signals to the pixel electrodes and supplies a common signal alternately switched between a first voltage and a second voltage higher than the first voltage to the common electrode;
a touch panel substrate that is laminated on the display panel and includes a plurality of detection electrodes; and
a detector circuit that performs touch detection on the detection electrodes,
wherein the detector circuit includes
a plurality of switch groups corresponding to the plurality of detection electrodes and connected to a common node within the detector circuit, each switch group including a first switch that is disposed between the corresponding detection electrode and the node and that is turned on or off, and a second switch that is disposed between the corresponding detection electrode and a grounding line that is integral with the detector circuit and that is turned on or off
a constant current source that maintains a constant current flowing between a power supply line and the node, and
a capacitor integral with the detector circuit is positioned outside the switch groups between the node and the grounding line, and between the constant current source and the grounding line,
wherein the detector circuit has a settling period in which alternately turning on and off the first and second switches is repeated and a counting period, which follows the setting period and in which touch detection on the detection electrode is performed on the basis of time required until a voltage at the node reaches a preset reference voltage while the first switch is turned off and the second switch is turned on, and
wherein the driver circuit switches the common signal between the voltages while the second switch is turned on in the settling period.
2. The device according to claim 1 , further comprising:
an oscillator that outputs a clock signal, wherein the driver circuit switches the common signal between the voltages in response to the clock signal, and
the driver circuit turns the first and second switches on and off in response to a signal, obtained by dividing the frequency of the clock signal, in the settling period.
3. The device according to claim 1 , wherein the detector circuit includes an oscillator that outputs a clock signal,
the detector circuit turns the first and second switches on and off in response to the clock signal in the settling period, and
the driver circuit switches the common signal between the voltages in response to a signal obtained by dividing the frequency of the clock signal.
4. The device according to claim 1 , wherein the driver circuit includes an oscillator that outputs a clock signal,
the driver circuit switches the common signal between the voltages in response to the clock signal, and
the detector circuit turns the first and second switches on and off in response to the clock signal in the settling period.
5. An electronic apparatus comprising the display device according to claim 1 .