DISPLAY DEVICE AND ELECTRONIC APPARATUS
First Claim
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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 detection electrode; and
a detector circuit that performs touch detection on the detection electrode, whereinthe detector circuit includesa constant current source that maintains current flowing between a power supply line and a predetermined node constant,a first switch that is disposed between the detection electrode and the node and is turned on or off,a second switch that is disposed between the detection electrode and a grounding line and is turned on or off, anda capacitor interposed between the node and the grounding line,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, andthe driver circuit switches the common signal between the voltages while the second switch is turned on in the settling period.
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Abstract
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.
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Citations
5 Claims
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1. A display device comprising:
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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 detection electrode; and a detector circuit that performs touch detection on the detection electrode, wherein the detector circuit includes a constant current source that maintains current flowing between a power supply line and a predetermined node constant, a first switch that is disposed between the detection electrode and the node and is turned on or off, a second switch that is disposed between the detection electrode and a grounding line and is turned on or off, and a capacitor interposed between the node and the grounding line, 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 the driver circuit switches the common signal between the voltages while the second switch is turned on in the settling period. - View Dependent Claims (2, 3, 4, 5)
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Specification