TOUCH PANEL
First Claim
1. A touch panel, comprising:
- a bias line, biased at a bias voltage;
a select line;
a readout line;
a photo cell, comprising;
a first photo TFT, having a first terminal, a second terminal and a control terminal, wherein the first terminal is coupled to the readout line and the control terminal is coupled to the select line;
a second photo TFT, having a first terminal, a second terminal and a control terminal, wherein the first terminal is coupled to the readout line, the second terminal and the control terminal are coupled to the bias line; and
a storage capacitor, coupling the second terminal of the first photo TFT to the bias line;
a readout circuit comprising;
an operational amplifier, having an inverting input terminal, a non-inverting input terminal and an output terminal, wherein the inverting input terminal is coupled to the readout line;
a feedback capacitor, coupled between the inverting input terminal and the output terminal of the operational amplifier; and
a first switch, coupled between the inverting input terminal and the output terminal of the operational amplifier, anda multiplexer for selectively outputting a reference voltage or the bias voltage to the non-inverting input terminal.
1 Assignment
0 Petitions
Accused Products
Abstract
Touch panels comprising a bias line biased at a bias voltage, a select line, a readout line, a photo cell and a readout circuit. The photo cell comprises a first photo switch, a second photo switch and a storage capacitor. The first photo switch and the storage capacitor is coupled in series between the readout line and the bias line, and the first photo switch is further controlled by the select line. The second photo switch is connected between the readout line and the bias line. The readout circuit and the select line are managed by a reset mode, an exposure mode and a readout mode. The voltage variation of output terminal of the readout circuit is used in obtaining the state of the photo cell.
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Citations
9 Claims
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1. A touch panel, comprising:
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a bias line, biased at a bias voltage; a select line; a readout line; a photo cell, comprising; a first photo TFT, having a first terminal, a second terminal and a control terminal, wherein the first terminal is coupled to the readout line and the control terminal is coupled to the select line; a second photo TFT, having a first terminal, a second terminal and a control terminal, wherein the first terminal is coupled to the readout line, the second terminal and the control terminal are coupled to the bias line; and a storage capacitor, coupling the second terminal of the first photo TFT to the bias line; a readout circuit comprising; an operational amplifier, having an inverting input terminal, a non-inverting input terminal and an output terminal, wherein the inverting input terminal is coupled to the readout line; a feedback capacitor, coupled between the inverting input terminal and the output terminal of the operational amplifier; and a first switch, coupled between the inverting input terminal and the output terminal of the operational amplifier, and a multiplexer for selectively outputting a reference voltage or the bias voltage to the non-inverting input terminal. - View Dependent Claims (2, 3, 4)
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5. A touch panel, comprising:
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a bias line; a select line; a readout line; and a photo cell, comprising; a storage capacitor; a first photo switch, connected between the storage capacitor and the readout line, and controlled by the select line; and a second photo switch, connected between the readout line and the bias line. - View Dependent Claims (6, 7, 8, 9)
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Specification