US 12,443,098 B2
Optical element, illumination apparatus, and projective display apparatus
Toshifumi Yasui, Kanagawa (JP); and Yusuke Kono, Kanagawa (JP)
Assigned to Sony Group Corporation, Tokyo (JP)
Appl. No. 17/916,973
Filed by SONY GROUP CORPORATION, Tokyo (JP)
PCT Filed Feb. 17, 2021, PCT No. PCT/JP2021/005841
§ 371(c)(1), (2) Date Oct. 4, 2022,
PCT Pub. No. WO2021/210260, PCT Pub. Date Oct. 21, 2021.
Claims priority of application No. 2020-072258 (JP), filed on Apr. 14, 2020.
Prior Publication US 2023/0161238 A1, May 25, 2023
Int. Cl. G03B 21/20 (2006.01)
CPC G03B 21/208 (2013.01) [G03B 21/2033 (2013.01)] 18 Claims
OG exemplary drawing
 
1. An illumination apparatus, comprising:
a light source;
an optical member including a first surface on which light from the light source is incident and a second surface facing the first surface; and
an integrator on which light emitted from the optical member is incident, wherein
the optical member is rotatable around a rotation axis extending parallel to a direction in which light from the light source is incident and is emitted,
a planar shape of the optical member is annular around the rotation axis,
multiple recessed and protruding structure units each having a fan-surface-like planar shape and including a recessed and protruding portion are consecutively formed on the first surface or the second surface of the optical member,
an extended line of a boundary between adjacent recessed and protruding structure units intersects the rotation axis,
when the boundary between the adjacent recessed and protruding structure units is a mirror plane, the adjacent recessed and protruding structure units are in a mirror symmetry relation, and recessed and protruding portions of the adjacent recessed and protruding structure units are smoothly connected together,
recessed portions and protruding portions of the recessed and protruding portion of each recessed and protruding structure unit are smoothly connected together, and
an area occupied by the recessed and protruding portion of each recessed and protruding structure unit is larger in size than incident light from the light source.