Patent ID: 9703425
Date: 2017-07-11
CPC Classifications: G06F

Claim:
1. A capacitive touch detecting device for detecting occurrence of a touch capacitance (Ct) by an approach of a bodily finger or a touch input instrument such as a conductor similar to the bodily finger, the capacitive touch detecting device comprising: a plurality of sensor patterns, each of the sensor patterns forming the touch capacitance (Ct) between the touch input instrument and the sensor pattern when a touch input occurs, wherein the sensor patterns are formed on the substrate and are formed of a transparent conductor; a common electrode that forms a common electrode capacitance (Cvcom) between each of the sensor patterns and the common electrode; a charging unit that supplies a charge signal to each of the sensor patterns to thus accumulate charges in the common electrode capacitance (Cvcom); and a level shift detecting unit that detects a level shift that occurs in a voltage variation in the sensor pattern at the time of occurrence of the touch input, with respect to another voltage variation in the sensor pattern at the time of non-occurrence of the touch input, to thereby acquire a touch signal, wherein the common electrode has a common voltage (Vcom) level that alternates at a predetermined frequency, wherein the level shift detecting unit detects a level shift between the voltage variations arising from the sensor pattern by the common voltage (Vcom) before and after the occurrence of the touch input, and wherein the sensor patterns are grouped and connected with the charging unit and the level shift detecting unit through a multiplexer, and signals from the sensor patterns within the group are multiplexed by the multiplexer and thus the signal from each of the sensor patterns is individually processed.