SIGNAL PROCESSING CIRCUIT, SIGNAL PROCESSING METHOD, POSITION DETECTOR, AND ELECTRONIC DEVICE

摘要

A signal processing circuit is connected to one of a plurality of conductors of a position detection sensor having a self-capacitance and configured to generate a signal indicative of the self-capacitance for use in correcting a pointer position detection signal. The circuit includes a capacitor circuit and detects a change in capacitance between the conductor and a pointer (e.g., a finger) as a change in voltage in the capacitor circuit. The signal processing circuit further includes: a gate circuit which controls the connection between the capacitor circuit and the conductor; and a voltage supply control circuit which temporarily sets, to a defined voltage level, a first end of the gate circuit to which the conductor is connected and sets a defined potential difference between the first end and another (second) end of the gate circuit to which the capacitor circuit is connected.

主权项

1. A signal processing circuit connected to one of a plurality of conductors of a position detection sensor having a self-capacitance, the signal processing circuit including a capacitor circuit and configured to detect a change in capacitance between the conductor and a pointer as a change in voltage in the capacitor circuit, the signal processing circuit further comprising:
a gate circuit which, in operation, controls the connection between the capacitor circuit and the conductor; and a voltage supply control circuit which, in cooperative operation with the gate circuit, temporarily sets, to a defined voltage level, a first end of the switching circuit to which the conductor is connected, and sets a defined potential difference between the first end of the gate circuit and a second end of the gate circuit to which the capacitor circuit is connected, wherein the signal processing circuit generates a signal corresponding to the self-capacitance of the position detection sensor based on a change in voltage, which occurs at the second end of the gate circuit due to the defined voltage level and the defined potential difference.