Patent ID: 7177260

Claim:
A reflection prism formed as a single body with a plurality of reflection faces to guide a light beam incident through a transmission face of the reflection prism in a first direction perpendicular to a second direction, by reducing a size of the light beam in the second direction by using a difference in angles between reflection faces of the reflection prism, and to reflect the guided light beam in the second direction by using a reflection face of an angle less than 45° with respect to the first direction, the reflection prism comprising: a first reflection face to reflect the light beam incident through the transmission face downward at an inclined angle with respect to the first and second directions; a plurality of waveguide reflection faces to guide the light beam, after having been reflected from the first reflection face, by reducing the size of the light beam in the second direction; and a second reflection face, which has an angle less than 45° with respect to the first direction, to reflect the light beam guided by the plurality of waveguide reflection faces.