HELMET POSITION DETECTING DEVICE

PROBLEM TO BE SOLVED: To detect the stepped position of a projection part by irradiating a slit light to the projection part preliminarily provided on a helmet, photographing the irradiated projection part, and arithmetically processing the resulting image signal. SOLUTION: When a laser beam source 1 irradiates a laser beam 9 to a projection part 6 obliquely from 45 under a photographing means 2, a bright line 10 is bent and produced according to the shape of the projection part 6. The periphery of the projection part 6 within a helmet is photographed by the photographing means 2, whereby an image having a bright line 11 can be provided. An analog image signal 13 showing this image 12 is transmitted from the means 2 to an image processing device. When the screen left upper corner is taken as the origin 0 of an XY coordinate system, and the screen horizontal direction and vertical direction are taken as X-axis and Y-axis, respectively, the line 11 of the image 12 is laid along X-direction, but dislocated in Y-direction in the middle in the form corresponding to the sectional form of the projection part 6 to form a stepped part 14. Thus, the X-coordinate value of the stepped part 14 in the image 12 is determined, whereby the position of the projection part 6 of the helmet, or the position of the helmet itself can be judged.