LASER BEAM IRRADIATION DETECTION DEVICE, LASER BEAM IRRADIATION DETECTION METHOD, AND LASER BEAM IRRADIATION DETECTION SYSTEM

摘要

A bandpass filter allows a light ray of a predetermined band including a wavelength band of a color of a laser beam, which is a target of detection, among light rays from a subject to pass therethrough. An imaging unit of a video camera captures the light ray passing through the bandpass filter. The controller analyzes a frequency for each brightness level of a video signal generated based on an imaging signal output from the imaging unit and detects a peak at which the frequency protrudes at a specific brightness level. The controller detects a trajectory of a straight light ray in a frame of the video signal. The controller detects that the laser beam is irradiated when the peak exists at a specific brightness level and the trajectory of the light ray exists in the frame.