# US 10,120,196 B2 · Optical device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,120,196 B2 - Document ID: US10120196B2 - Status: Granted - Kind: B2 - Application number: 15/281,099 - Filed: 2016-09-30 - Published: 2018-04-05 - Granted: 2018-11-06 - Earliest claimed: 2016-09-30 - Assignees: National Taiwan University of Science and Technology - Applicants: National Taiwan University of Science and Technology - Inventors: Jeng-Ywan Jeng; Mohammad Hossein Goudarzi Khouygani; Chyan-Chyi Wu - Web page: https://patentgrep.com/patent/US10120196B2 ## CPC - G02B 27/14: operating by reflection only - G01B 11/026: {by measuring distance between sensor and object (G01B11/0608 takes precedence)} - G01C 3/00: Measuring distances in line of sight; Optical rangefinders (tapes, chains or wheels for measuring length G01B3/00; active triangulation systems, i.e. using the transmission and reflection of electromagnetic waves other than radio waves, G01S17/48) - G02B 27/4233: {having a diffractive element [DOE] contributing to a non-imaging application (diffusers having a diffractive element G02B5/0252; filters having a diffractive element G02B5/203; systems for controlling the direction of light having diffractive elements G02B26/0808; scanning systems having diffractive elements G02B26/106; beam shaping systems using diffractive optical elements G02B27/0944; beam splitting or combining systems operating by diffraction G02B27/1086)} - G02B 5/04: Prisms - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS - G01B: MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS - G01C: MEASURING DISTANCES, LEVELS OR BEARINGS; SURVEYING; NAVIGATION; GYROSCOPIC INSTRUMENTS; PHOTOGRAMMETRY OR VIDEOGRAMMETRY (measuring liquid level G01F; radio navigation, determining distance or velocity by use of propagation effects, e.g. Doppler effects, propagation time, of radio waves, analogous arrangements using other waves G01S) ## 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. ## Claims ### Claim 1 An optical device configured for measuring a distance, comprising: a prism having a first light-incident surface and a plurality of first light-transmitting surfaces, the first light-incident surface being disposed opposite to the first light-transmitting surfaces, the first light-transmitting surfaces being mutually inclined and intersecting at a vertex; a beam splitter having a light-passing surface, and a second light-incident surface and a second light-transmitting surface mutually connected, the second light-incident surface at least partially facing to the first light-transmitting surfaces, the light-passing surface being disposed opposite to the second light-incident surface, the beam splitter further comprising a partially mirror surface therein, the partially mirror surface at least partially facing to the light-passing surface and the second light-incident surface, the light-passing surface being configured to face to a grating; a detector corresponding to the second light-transmitting surface; and a light source configured to emit a light beam to enter into the prism through the first light-incident surface, an optical axis of the light beam passing through the vertex and the beam splitter, the first light-transmitting surfaces being configured to retract the light beam away the prism. ### Claim 2 (depends on 1) The optical device of claim 1, wherein the vertex is away from the light source. ### Claim 3 (depends on 1) The optical device of claim 1, wherein each of the first light-transmitting surfaces is substantially a flat surface. ### Claim 4 (depends on 1) The optical device of claim 1, wherein the light source, the vertex and the beam splitter are substantially aligned in a straight line. ### Claim 5 (depends on 1) The optical device of claim 1, wherein the first light-incident surface comprises: a plurality of subsidiary light-incident surfaces mutually connected and intersecting at a recessed angle less than 180 degree outside the prism. ### Claim 6 (depends on 5) The optical device of claim 5, wherein the subsidiary light-incident surfaces form together a recessed shape and the first light-transmitting surfaces form together a protruding shape, such that the prism is in a V shape. ### Claim 7 (depends on 1) The optical device of claim 1, wherein the first light-incident surface comprises: a plurality of subsidiary light-incident surfaces mutually connected and intersecting at a protruding angle more than 180 degree outside the prism. ### Claim 8 (depends on 7) The optical device of claim 7, wherein the subsidiary light-incident surfaces form together a protruding shape and the first light-transmitting surfaces are of a same plane, such that the prism is in a Δ shape. ### Claim 9 (depends on 1) The optical device of claim 1, wherein the second light-transmitting surface and the light-passing surface are mutually connected. ### Claim 10 (depends on 1) The optical device of claim 1, wherein the prism comprises a transparent material against the light beam. ### Claim 11 (depends on 1) The optical device of claim 1, wherein the light source is configured to emit a coherent light. ### Claim 12 (depends on 1) The optical device of claim 1, wherein the light beam refracted by the first light-transmitting surfaces forms at least two refracted light beams, such that an angle between the refracted light beams after refracted by each of the first light-transmitting surfaces is equal to an integer multiple of a ratio of a wavelength of the light beam to a pitch of the grating. ### Claim 13 (depends on 1) The optical device of claim 1, wherein the prism locates between the light source and the beam splitter. ### Claim 14 (depends on 1) The optical device of claim 1, wherein an angle between a normal of the first light-incident surface and a normal of each of the first light-transmitting surfaces is in a range between 0 degree and 90 degree.