US 12,449,537 B2
Optical distance measurement device
Takanori Yamauchi, Tokyo (JP); Hiroki Goto, Tokyo (JP); Tsuyoshi Yoshida, 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 Sep. 1, 2021, as Appl. No. 17/463,651.
Application 17/463,651 is a continuation of application No. PCT/JP2019/015131, filed on Apr. 5, 2019.
Prior Publication US 2021/0396880 A1, Dec. 23, 2021
Int. Cl. G01S 17/32 (2020.01); G01B 9/02004 (2022.01); G01B 9/02015 (2022.01); G01S 7/481 (2006.01)
CPC G01S 17/32 (2013.01) [G01B 9/02004 (2013.01); G01B 9/02027 (2013.01); G01S 7/4814 (2013.01)] 7 Claims
OG exemplary drawing
 
1. An optical distance measurer comprising a transmitter, a first receiver, and a second receiver,
the transmitter comprising:
a beam splitter splitting a laser beam into measurement light and reference light and outputting the measurement light and the reference light, the laser beam, the input of the beam splitter, being a continuous wave;
a measurement light beam splitter splitting the measurement light into first measurement light and second measurement light and outputting the first measurement light and the second measurement light;
a reference light beam splitter splitting the reference light into first reference light and second reference light and outputting the first reference light and the second reference light;
a first optical system having a first Rayleigh length, the first optical system emitting the first measurement light to a target object; and
a second optical system having a second Rayleigh length different from the first Rayleigh length and a focal length equal to a focal length of the first optical system, the second optical system emitting the second measurement light to the target object;
wherein the first receiver receives the first reference light and first reflection light and outputs a first receiving signal having information on both the first reference light and the first reflection light, the first reflection light being a reflected light reflected at the target object and originally being the first measurement light; and
the second receiver receives the second reference light and second reflection light and outputs the second receiving signal having information on both the second reference light and the second reflection light, the second reflection light being another reflected light reflected at the target object and originally being the second measurement light.