Method of driving touch panel, capacitance-type touch panel, and display apparatus with detection function
First Claim
1. A capacitance-type touch panel comprising:
- a plurality of drive electrodes;
a drive control circuit which selectively applies a drive signal for touch detection to the drive electrodes;
a plurality of touch detection electrodes which form capacitance with the drive electrodes, each of the touch detection electrodes outputting a detection signal in synchronization with the drive signal; and
a detection circuit which detects an external proximity object based on the detection signals, wherein the drive control circuit applies the drive signal such that a positive drive signal is selectively applied to a first one of the drive electrodes having a first width that is a total width of the drive electrodes belonging to a first group, in a first period wherein a negative drive signal is applied to a second group of drive electrodes in a second period different from the first period, the second group being divided into discretely arranged sub groups and each of the sub groups having a second width that is a total width of the drive electrodes belonging to each of the sub groups of the second group,wherein the first width is greater than the second width, and wherein the detection circuit detects the external proximity object based on a shift of the time-average level of the detection signal both in the first period and the second period with respect to a center voltage of the detection signal.
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Accused Products
Abstract
A capacitance-type touch panel, allowing disturbance noise and touch detection time to be reduced and having a simple configuration, is provided. The capacitance-type touch panel including: a plurality of drive electrodes each having a strip shape; a drive control circuit performing control such that a drive signal for touch detection is selectively applied to the drive electrodes; a plurality of touch detection electrodes arranged to intersect with the drive electrodes in such a manner that capacitance is formed in each intersecting part, and each outputting a detection signal in synchronization with the drive signal; and a detection circuit detecting an external proximity object based on the detection signal. The drive control circuit controls application of the drive signal in such a manner that the detection signal is a polarity-alternating signal including a positive-negative asymmetrical signal component which is due to presence of the external proximity object.
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Citations
15 Claims
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1. A capacitance-type touch panel comprising:
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a plurality of drive electrodes; a drive control circuit which selectively applies a drive signal for touch detection to the drive electrodes; a plurality of touch detection electrodes which form capacitance with the drive electrodes, each of the touch detection electrodes outputting a detection signal in synchronization with the drive signal; and a detection circuit which detects an external proximity object based on the detection signals, wherein the drive control circuit applies the drive signal such that a positive drive signal is selectively applied to a first one of the drive electrodes having a first width that is a total width of the drive electrodes belonging to a first group, in a first period wherein a negative drive signal is applied to a second group of drive electrodes in a second period different from the first period, the second group being divided into discretely arranged sub groups and each of the sub groups having a second width that is a total width of the drive electrodes belonging to each of the sub groups of the second group, wherein the first width is greater than the second width, and wherein the detection circuit detects the external proximity object based on a shift of the time-average level of the detection signal both in the first period and the second period with respect to a center voltage of the detection signal. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A display apparatus with a touch detection function comprising:
- a pixel substrate;
an opposite substrate opposed to the pixel substrate; a plurality of pixel electrodes included in the pixel substrate; a plurality of drive electrodes included in the pixel substrate;
a drive control circuit selectively applying a drive signal for touch detection to the drive electrodes, the drive signal for touch detection also serving as a drive signal for driving the display and a plurality of touch detection electrodes arranged to form capacitance with the drive electrodes, each outputting a detection signal in synchronization with the drive signal;
a detection circuit detecting an external proximity object based on the detection signal; anda display section displaying an image based on an image signal, wherein the drive control circuit controls application of the drive signal such that a positive drive signal is selectively applied to display a first group of drive electrodes having a first width that is a total width of the drive electrodes belonging to a first group, in a first period, wherein a negative drive signal is applied to display a second group of drive electrodes in a second period different from the first period, the second group being divided into discretely arranged sub groups, and each of the sub groups having a second width that is a total width of the drive electrodes belonging to each of the sub groups of the second group; wherein the first width is greater than the second width and wherein the detection circuit detects the external proximity object based on a shift of the time-average level of the detection signal both in the first period and the second period with respect to the a center voltage of the detection signal. - View Dependent Claims (9, 10, 11, 12, 13, 14)
- a pixel substrate;
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15. A method of driving a touch panel, comprising steps of:
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selectively applying a drive signal for touch detection to a plurality of drive electrodes; outputting a detection signal in synchronization with the drive signal from each of a plurality of touch detection electrodes for an external proximity object, the touch detection electrodes being arranged to form capacitance with the drive electrodes; applying the detection signal such that a positive drive signal is a drive signal that is selectively applied to a first group of drive electrodes having a first width that is a total width of drive electrodes belonging to the first group, in a first period and a negative drive signal is applied to a predetermined second group of drive electrodes in a second period that is different from the first period, the second group being divided into discretely arranged sub groups, each of the sub groups having a second width that is a total width of the drive electrodes belonging to each of the sub groups of the second group; and detecting the external proximity object based a shift of the time-average level of the detection signal both in the first period and the second period with respect to the center voltage of the detection signal.
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Specification