| 摘要 |
PURPOSE:To obtain a sensor miniaturized and receiving no interference of a structure, by providing one set of projection parts each consisting of a laser oscillator and a condensing lens to a central part and arranging a plurality of light receiving parts each consisting of a light receiving lens and a light receiving element therearound. CONSTITUTION:The laser beam L from a laser oscillator S1 is condensed by a condensing lens S2 to irradiate the surface to be irradiated of an article to be processed and the reflected beam from said article passes through light receiving lenses AC, C2 to be formed into an image on each of light receiving elements A1-D1. At this time, the incident angle of the beam L to the surface to be irradiated is inclined and the quantity of the beam received by the light receiving element on a side large in the incident angle to the surface to be irradiated (or opposite side) increases (or decreases). By this mechanism, output difference is generated between each of the elements A1-D1 and the deflection of the angle of irradiation from the vertical line to the surface to be irradiated is detected. When the position of the surface to be irradiated is present at the predetermined position in the vicinity of the beam condensing position, the reflected light L is formed into an image at the predetermined position of the element A1 or the like but, when said position is displaced in the irradiated beam direction of the beam L, the light receiving position on the element A1 also similarly changes and each output also changes and the above-mentioned deflection of the surface to be irradiated is detected. |
