US 12,259,320 B2
Imaging device
Yosuke Asai, Osaka (JP); Kazuhiro Yamada, Osaka (JP); and Hiroshi Yamaguchi, Osaka (JP)
Assigned to PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO., LTD., Osaka (JP)
Filed by Panasonic Intellectual Property Management Co., Ltd., Osaka (JP)
Filed on Sep. 8, 2022, as Appl. No. 17/940,372.
Application 17/940,372 is a continuation of application No. PCT/JP2020/047117, filed on Dec. 17, 2020.
Claims priority of application No. 2020-048096 (JP), filed on Mar. 18, 2020.
Prior Publication US 2023/0003643 A1, Jan. 5, 2023
Int. Cl. G01N 21/3581 (2014.01); G01B 11/30 (2006.01)
CPC G01N 21/3581 (2013.01) [G01B 11/303 (2013.01)] 10 Claims
OG exemplary drawing
 
1. An imaging device comprising:
an area light source including an emission surface from which a sub-terahertz wave is emitted to a measurement target; and
a detector including an image sensor that receives a reflected wave generated by the measurement target reflecting the sub-terahertz wave emitted from the emission surface,
wherein the area light source includes:
at least one point light source that emits a sub-terahertz wave; and
a reflector that diffusely reflects the sub-terahertz wave emitted from the at least one point light source, to generate a sub-terahertz wave to be emitted from the emission surface, the reflector including a reflection surface that is a bumpy surface which is of a shape in which a plurality of protruding portions having mutually different shapes and a plurality of recessed portions having mutually different shapes are randomly arranged, includes two or more frequency components in a spatial frequency range and whose roughness curve element mean length RSm is at least 0.3 mm.