TOUCH SWITCH SYSTEM AND TOUCH DETECTION METHOD FOR TOUCH SWITCH SYSTEM

摘要

To provide a touch switch system that can improve touch detection accuracy even in the presence of noise.SOLUTION: The touch switch system includes: a signal reception section 501 for receiving a sine wave component and a cosine wave component from a conversion section 50A; an offset signal determination section 502 for determining a sine wave offset signal and a cosine wave offset signal on the basis of a first sine wave component and a first cosine wave component when a drive AC current does not flow to a drive electrode and an offset coefficient; a difference calculation section 503 for calculating a sine wave difference between a second sine wave component when the drive AC current flows to the drive electrode and the sine wave offset signal and calculating a cosine wave difference between a second cosine wave component when the drive AC current flows to the drive electrode and the cosine wave offset signal; an effective value calculation section 504 for calculating an effective value of a differential signal from the sine wave difference and the cosine wave difference; and a touch detection section 505 for detecting a touch on a switch section on the basis of the effective value of the differential signal.SELECTED DRAWING: Figure 4