LIGHT WAVE RANGE FINDER

PROBLEM TO BE SOLVED: To provide an inexpensive and miniaturizable light wave range finder having a wide measuring range from a short distance to a long distance. SOLUTION: This range finder is equipped with a light emitting element 11 for emitting measuring light 30; a floodlighting optical element 15 for collimating the measuring light 30; a light separation surface 181 for separating incident light into reflected light and transmitted light; a light reflection surface 182 for reflecting the measuring light 30 transmitted through the light separation surface 181 to reach a measuring object 21; a light receiving optical element 16 for receiving, condensing and emitting the first return light 321 formed by reflection of return light 32 by the light separation surface 181 and the second return light 322 formed by reflection of the return light 32 by the light reflection surface 182; and a light receiving element 12 for converting light condensed by the light receiving optical element 16 into an electric signal. The range finder has a characteristic wherein, when light is allowed to enter the light separation surface 181, the intensity of light reflected by the light separation surface 181 is less than the intensity of light reflected by the light reflection surface 182 after being transmitted through the light separation surface 181. COPYRIGHT: (C)2009,JPO&INPIT