Patent ID: 7431700

Claim:
A monitor comprising: lighting pattern projecting means for projecting a specified lighting pattern; image pickup means, whose optical axis is different from that of the lighting pattern projecting means, for picking up light of a projected wavelength continuously; moving amount calculating means for calculating an inter-frame moving amount of the lighting pattern from two frames of images acquired by the image pickup means at different times; moving amount waveform generating means for generating moving amount waveform data comprising inter-frame moving amounts arranged in time series; and waveform detecting means for detecting a movement of an object to be picked up from the moving amount waveform data; wherein the lighting pattern projecting means projects the lighting pattern that has a plurality of lighting spots or slit rays; and the moving amount calculating means calculates an inter-frame moving amount of each lighting spot in an axial direction connecting the lighting pattern projecting means and the image pickup means while providing a positive or negative sign in accordance with a moving direction, and calculates a sum of moving amounts of pixels corresponding to the plurality of lighting spots or slit rays.