US 11,940,720 B2
Optical system and image projection apparatus
Kei Nojima, Tokyo (JP)
Assigned to RICOH COMPANY, LTD., Tokyo (JP)
Appl. No. 17/772,140
Filed by Kei Nojima, Tokyo (JP)
PCT Filed Nov. 10, 2020, PCT No. PCT/IB2020/060546
§ 371(c)(1), (2) Date Apr. 27, 2022,
PCT Pub. No. WO2021/099884, PCT Pub. Date May 27, 2021.
Claims priority of application No. 2019-210143 (JP), filed on Nov. 21, 2019.
Prior Publication US 2022/0397814 A1, Dec. 15, 2022
Int. Cl. G03B 21/20 (2006.01); G03B 21/00 (2006.01)
CPC G03B 21/2046 (2013.01) [G03B 21/008 (2013.01); G03B 21/2066 (2013.01)] 12 Claims
OG exemplary drawing
 
1. An optical system comprising:
an optical modulation element to reflect and emit an incident light in a different direction; and
an illumination optical system through which light emitted from a light source is emitted toward the optical modulator,
wherein the illumination optical system includes a lens array and a lens disposed in an order listed from the light source to the optical modulator,
wherein the illumination optical system includes a shielding part disposed closer to the light source than the lens,
wherein the shielding part is configured to shield light incident on an effective diameter of the lens, and
wherein, in a direction perpendicular to an optical axis of the light emitted from the light source, the optical axis of the light emitted from the light source is shifted from a center position of the effective diameter of the lens in an opposite direction with reference to the shielding part.