We developed a new diagnostic method by using laser beam. The tooth surface is irradiated by zonal laser beam from oblique direction, and then irradiated laser beam line is shifted along the height of the tooth according to gear revolution. The variations of laser reflection between the initial and the present conditions are compared, and it can estimate a condition on a tooth surface such as initial or abnormal abrasion, pitting, etc. We developed a method of automatic and remote damage diagnosis on a gear tooth surface. By using this method, we can estimate and diagnosis automatically in consideration of influence of adjacent teeth by using an ideal measurement voltage based on each gear geometry.
