Patent ID: 9746589
Date: 2017-08-29
CPC Classifications: G01C,G01S,G02B

Claim:
1. A prism assembly comprising: a first prism which comprises a first surface, a second surface and a third surface; a second prism which comprises a fourth surface, a fifth surface and a sixth surface, wherein the fifth surface faces the third surface; a roof prism which comprises a seventh surface, an eighth surface and a ridge surface, wherein the seventh surface faces the second surface; and an optical multilayer film which is disposed between the fifth surface and the third surface; wherein a first light beam and a second light beam incident on the first surface of the first prism are totally reflected from the second surface to the optical multilayer film, the optical multilayer film reflects the first light beam but allows the second light beam to pass through and enter the second prism, the second light beam is incident on the fifth surface of the second prism and totally reflected by the sixth surface so that a propagation direction thereof is changed, and the second light beam exits from the fourth surface of the second prism.