US 11,953,705 B2
Optical device and prism module thereof
Bin Liu, ShenZhen (CN); and Hua-Tang Liu, Taichung (TW)
Assigned to SINTAI OPTICAL (SHENZHEN) CO., LTD., Shenzhen (CN); and ASIA OPTICAL CO., INC., Taichung (TW)
Filed by Sintai Optical (Shenzhen) Co., Ltd., ShenZhen (CN); and Asia Optical Co., Inc., Taichung (TW)
Filed on Apr. 8, 2021, as Appl. No. 17/301,577.
Claims priority of application No. 202010297240.8 (CN), filed on Apr. 15, 2020.
Prior Publication US 2021/0325578 A1, Oct. 21, 2021
Int. Cl. G02B 5/04 (2006.01); G01C 3/08 (2006.01); G01S 7/481 (2006.01); G01S 17/08 (2006.01)
CPC G02B 5/04 (2013.01) [G01C 3/08 (2013.01); G01S 7/481 (2013.01); G01S 17/08 (2013.01)] 16 Claims
OG exemplary drawing
 
1. A prism module, comprising:
a first prism comprising a first surface, a second surface, a third surface and a fourth surface wherein the first surface adjoins the third surface, the third surface adjoins the second surface, the second surface adjoins the fourth surface, the fourth surface adjoins the first surface, the first surface is opposite to the second surface, and the third surface is opposite to the fourth surface;
a second prism comprising a fifth surface, a sixth surface and a seventh surface wherein the fifth surface adjoins the sixth surface and the seventh surface, and the seventh surface of the second prism is disposed beside the third surface of the first prism;
a third prism comprising an eighth surface, a ninth surface and a tenth surface wherein the eighth surface adjoins the ninth surface and the tenth surface, and the eighth surface of the third prism is disposed to face the sixth surface of the second prism;
a first coating disposed between the third surface and the seventh surface;
wherein a first light beam is emitted by an object, enters the first prism through the first surface, is reflected on the fourth surface, sequentially passes through the third surface and the seventh surface, enters the second prism, is reflected on the fifth surface, leaves from the sixth surface of the second prism, enters the third prism through the eighth surface, is sequentially reflected on the ninth surface and the tenth surface, passes through the eighth surface and leaves the third prism;
wherein the first light beam passes through the first coating and propagates towards the seventh surface.