US 12,228,645 B2
Distance-measuring sensor
Takao Taguchi, Minamiashigara (JP); Yukito Saitoh, Minamiashigara (JP); Hiroshi Sato, Minamiashigara (JP); Katsumi Sasata, Minamiashigara (JP); and Akiko Watano, Minamiashigara (JP)
Assigned to FUJIFILM Corporation, Tokyo (JP)
Filed by FUJIFILM Corporation, Tokyo (JP)
Filed on Nov. 9, 2021, as Appl. No. 17/521,983.
Application 17/521,983 is a continuation of application No. PCT/JP2020/018553, filed on May 7, 2020.
Claims priority of application No. 2019-089780 (JP), filed on May 10, 2019; and application No. 2019-238684 (JP), filed on Dec. 27, 2019.
Prior Publication US 2022/0066030 A1, Mar. 3, 2022
Int. Cl. G01S 17/08 (2006.01); G02B 1/08 (2006.01); G02B 5/20 (2006.01); G02B 5/30 (2006.01); G02F 1/1335 (2006.01); G02F 1/137 (2006.01)
CPC G01S 17/08 (2013.01) [G02B 1/08 (2013.01); G02B 5/3016 (2013.01); G02F 1/133543 (2021.01); G02F 1/13718 (2013.01); G02B 5/20 (2013.01); G02F 2201/343 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A sensor comprising:
a light source;
a band pass filter; and
a light-receiving element,
wherein the band pass filter includes a cholesteric liquid crystal layer that is a layer obtained by immobilizing a cholesteric liquid crystalline phase,
the cholesteric liquid crystal layer has a region where a refractive index nx in an in-plane slow axis direction and a refractive index ny in an in-plane fast axis direction satisfy nx>ny,
in a case where a selective reflection center wavelength of the cholesteric liquid crystal layer is represented by λ, the cholesteric liquid crystal layer has a second selective reflection peak at a wavelength λ/2 and a half-width of the second selective reflection peak at λ/2 is 30 nm or less,
the light source emits light having a wavelength in a wavelength range of the second selective reflection peak,
the light-receiving element has sensitivity to light having a wavelength in a wavelength range of the second selective reflection peak, and
the light source emits light toward an object, the band pass filter reflects light having the wavelength of the second selective reflection peak in the light reflected from the object, and the light-receiving element receives light having the wavelength of the second selective reflection peak and being reflected from the band pass filter.