US 12,379,494 B2
Optical distance measurement device and machining device
Takanori Yamauchi, Tokyo (JP); Hiroki Goto, Tokyo (JP); Kiyoshi Onohara, Tokyo (JP); and Naoki Suzuki, Tokyo (JP)
Assigned to MITSUBISHI ELECTRIC CORPORATION, Tokyo (JP)
Filed by Mitsubishi Electric Corporation, Tokyo (JP)
Filed on Mar. 17, 2022, as Appl. No. 17/697,189.
Application 17/697,189 is a continuation of application No. PCT/JP2019/041084, filed on Oct. 18, 2019.
Prior Publication US 2022/0206145 A1, Jun. 30, 2022
Int. Cl. G01S 17/08 (2006.01); G01B 9/02 (2022.01); G01S 7/481 (2006.01); G01S 17/34 (2020.01)
CPC G01S 17/08 (2013.01) [G01B 9/02 (2013.01); G01S 7/4817 (2013.01); G01S 17/34 (2020.01)] 6 Claims
OG exemplary drawing
 
1. An optical distance measurement device comprising:
a splitter to split laser light into measurement light and reference light;
a measurement light splitter to split the measurement light generated by the splitter into first measurement light and second measurement light;
a first optical system to irradiate a target object with the first measurement light generated by the measurement light splitter and to receive first reflected light reflected by the target object;
a second optical system to emit the second measurement light generated by the measurement light splitter toward a space between the first optical system and the target object;
a reflector to reflect the second measurement light emitted from the second optical system and passing through the space toward the second optical system;
and processing circuitry
to calculate a first optical path length from an emission surface of the first optical system to a reflection surface of the target object on the basis of the first reflected light received by the first optical system and the reference light generated by the splitter, and to calculate a second optical path length from an emission surface of the second optical system to a reflection surface of the reflector on the basis of second reflected light reflected by the reflector and received by the second optical system and the reference light generated by the splitter; and
to calculate a refractive index of the space on the basis of the second optical path length, and to calculate a distance from the emission surface of the first optical system to the reflection surface of the target object on the basis of the refractive index and the first optical path length.