| 摘要 |
PROBLEM TO BE SOLVED: To attain an optical path conversion element that reduces costs, a cumbersome operation and the like.SOLUTION: The optical path conversion element according to the present invention includes: an incident surface to which light is incident; a first reflection surface that reflects the light incident to the light incident surface and passing through the incident surface; a second reflection surface that reflects the light reflected by the first reflection surface; an emergent surface from which the light reflected by the second reflection surface is emergent; and a surface that does not transmit the light nor reflect the light. An angle between the first reflection surface and the second reflection surface is (90-&thetas;/2) degree, an angle between the incident surface and the emergent surface is (180-&thetas;) degree, an angle between the incident surface and the second reflection surface is (45+(3/4)&thetas;-sin{(n/n)sin&phgr;}) degree, and an angle between the emergent surface and the first reflection surface is (45+(3/4)&thetas;+sin{(n/n)sin&phgr;}) degree. |
