Readout circuit for touch sensor
First Claim
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1. A readout circuit connected to each of readout lines from a touch sensor, comprising:
- a comparative circuit for setting an input range of a readout signal from the readout line as well as scaling the readout signal to be a required driving range and forwarding the readout signal scaled thus as a touch sensing signal; and
an analog to digital converter for converting the touch sensing signal from the comparative circuit as a digital sensing signal and forwarding the digital sensing signal,wherein the comparative circuit includes;
a plurality of amplifiers connected to the readout line as one channel in series and inputting respectively a plurality of reference voltages for limiting the input range of the readout signal, wherein the plurality of reference voltages are different each other; and
a plurality of gain capacitors connected respectively to the plurality of amplifiers and connected each other in series for scaling the readout signal.
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Abstract
The present invention relates to a readout circuit for a touch sensor which can increase touch sensing sensitivity regardless of a process variation and a driving voltage of the touch sensor.
The readout circuit includes a comparative circuit for setting an input range of a readout signal from the readout line as well as scaling the readout signal to be a required driving range and forwarding the readout signal scaled thus as a touch sensing signal, and an analog to digital converter for converting the touch sensing signal from the comparative circuit as a digital sensing signal and forwarding the digital sensing signal.
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9 Claims
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1. A readout circuit connected to each of readout lines from a touch sensor, comprising:
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a comparative circuit for setting an input range of a readout signal from the readout line as well as scaling the readout signal to be a required driving range and forwarding the readout signal scaled thus as a touch sensing signal; and an analog to digital converter for converting the touch sensing signal from the comparative circuit as a digital sensing signal and forwarding the digital sensing signal, wherein the comparative circuit includes; a plurality of amplifiers connected to the readout line as one channel in series and inputting respectively a plurality of reference voltages for limiting the input range of the readout signal, wherein the plurality of reference voltages are different each other; and a plurality of gain capacitors connected respectively to the plurality of amplifiers and connected each other in series for scaling the readout signal. - View Dependent Claims (2, 3)
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4. A readout circuit connected to each of readout lines from a touch sensor, comprising:
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a plurality of comparative circuits for setting input ranges of a readout signal from the readout line different from one another as well as scaling the readout signal to be required driving ranges different from one another and forwarding the readout signals scaled thus as a plurality of touch sensing signals, respectively; and a plurality of analog to digital converters for converting the touch sensing signals from the plurality of comparative circuits as digital sensing signals and forwarding the digital sensing signals, respectively, wherein each of the plurality of comparative circuits includes; a plurality of amplifiers connected to the readout line as one channel in series and inputting respectively a plurality of reference voltages for limiting the input range of the readout signal, wherein the plurality of reference voltages are different each other; and a plurality of gain capacitors connected respectively to the plurality of amplifiers and connected each other in series for scaling the readout signal. - View Dependent Claims (5, 6, 7, 8, 9)
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Specification