Patent ID: 10120196

Abstract:
An optical device for measuring a distance includes a prism, a beam splitter, a detector and a light source. The prism has a first light-incident surface and a plurality of first light-transmitting surfaces. The first light-incident surface is opposite to the first light-transmitting surfaces. The first light-transmitting surfaces intersect at a vertex. The beam splitter has a light-passing surface, a second light-incident surface and a second light-transmitting surface. The second light-incident surface faces the first light-transmitting surfaces. The light-passing surface is opposite to the second light-incident surface. The beam splitter includes a partially mirror surface facing the light-passing surface and the second light-incident surface. The light-passing surface faces a grating. The detector corresponds to the second light-transmitting surface. The light source emits a light beam to the first light-incident surface. An optical axis of the light beam passes through the vertex and the beam splitter.