CONTACT DETECTOR AND CONTACT DETECTION METHOD

摘要

A tapping counter (1) is a detector for detecting contact of a finger tip (20) with a plate (30), and comprises a photography section (11) for photographing the finger tip (20) and the plate (30), a distance measuring section (13) for measuring a first time series variation in distance from the finger tip (20) to the plate (30) based on the positions thereof in an image photographed at the photography section (11), a high-pass filter (14) for extracting time series variation in frequency components of the cut-off frequency or above among the first time series variation measured at the distance measuring section (13) as second time series variation, and a section (15) for detecting contact of the finger tip (20) with the plate (30) when the second time series variation extracted by the high-pass filter (14) exceeds a threshold.