Abstract
In this paper, it is demonstrated that object shape is detected easily by scanning with a coaxial laser beam. The coaxial laser beam consists of the He-Ne laser and laser diode beams which are different in diameter. The lights scattered from the object are detected individually through the respective optical filters. The edge position of the object is obtained from the difference between the two light intensities. The image of the object edge is obtained instantaneously only by scanning with the laser beam since the object edge is enhanced in a manner similar to the biological receptive field. The edge enhancement is also explained theoretically.
