US 12,339,622 B2
Light irradiating device and sensor
Hiroshi Sato, Minamiashigara (JP); Katsumi Sasata, Minamiashigara (JP); and Yukito Saitoh, Minamiashigara (JP)
Assigned to FUJIFILM Corporation, Tokyo (JP)
Filed by FUJIFILM Corporation, Tokyo (JP)
Filed on Oct. 22, 2021, as Appl. No. 17/508,426.
Application 17/508,426 is a continuation of application No. PCT/JP2020/017706, filed on Apr. 24, 2020.
Claims priority of application No. 2019-090083 (JP), filed on May 10, 2019.
Prior Publication US 2022/0043395 A1, Feb. 10, 2022
Int. Cl. G02F 1/1343 (2006.01); G01B 11/25 (2006.01); G03H 1/22 (2006.01)
CPC G03H 1/2294 (2013.01) [G01B 11/254 (2013.01); G02F 1/134309 (2013.01); G03H 1/2205 (2013.01); G03H 2223/17 (2013.01); G03H 2223/22 (2013.01); G03H 2223/23 (2013.01); G03H 2225/36 (2013.01); G03H 2225/60 (2013.01)] 16 Claims
OG exemplary drawing
 
1. A light irradiating device comprising:
a light source; and
a liquid crystal hologram element,
wherein light that originates from the light source and is incident on the liquid crystal hologram element is diffracted by the liquid crystal hologram element in a plurality of different directions as the light passes therethrough,
the liquid crystal hologram element includes a liquid crystal hologram layer,
the liquid crystal hologram layer is a layer that consists of a computer generated hologram and is formed of a composition including a liquid crystal compound,
the liquid crystal hologram layer includes a plurality of regions in which directions of optical axes derived from the liquid crystal compound are different from each other,
the computer generated hologram is formed by two-dimensionally arranging the plurality of regions so that a dot pattern is projected to an object to be detected, and
the light irradiating device further comprises a polarization switching element provided between the light source and the liquid crystal hologram element, wherein the light from the light source is polarized and the polarization switching element switches a polarization state of the light emitted from the light source.