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US 2010/0060610 A1Published application
Sensing circuit for capacitive touch panel
AssigneeTPO Displays Corp.
InventorTse-Hung WU
Life of this patent
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Abstract
A sensing circuit for a capacitive touch panel is disclosed. By adding a path for a noise to pass through, the noise is differentially processed through two paths which have the same electrical conditions with each other. The noise is then decreased significantly, and a sensing signal can be detected correctly.
Claims20
A sensing circuit for a capacitive touch panel, comprising:
- a sensing signal part for generating a sensing signal according to a capacitance of the capacitive touch panel and a noise which is received by the sensing signal part, wherein the capacitance of the capacitive touch panel at a touched condition is different from the capacitance of the capacitive touch panel at an untouched condition;
- a reference signal part for receiving the noise and outputting a reference signal, the reference signal part having the same electrical conditions as the sensing signal part;
- and
- an integrator for receiving the sensing signal and the reference signal, subtracting the reference signal from the sensing signal to generate an output signal.
1 more element
A sensing circuit for a capacitive touch panel, comprising:
- a sensing signal path for generating a sensing signal according to a capacitance of the capacitive touch panel and a noise which is received by the sensing signal path, wherein the capacitance of the capacitive touch panel at a touched condition is different from the capacitance of the capacitive touch panel at an untouched condition;
- a reference signal path for receiving the noise and outputting a reference signal, the reference signal path having the same electrical conditions as the sensing signal path;
- and
- a first differential amplifier for receiving the sensing signal and the reference signal, subtracting the reference signal from the sensing signal to generate an output signal.
1 more element
Dependencies are inferred from the claim text.