Reflection type field angle conversion optical device

摘要

The optical device comprises a main mirror (8) having a reflecting surface of rotationally symmetrical shape for reflecting the incident light (12) as primary reflected light (13), a sub-mirror (10) having a reflecting surface of rotationally symmetrical shape with respect to the axis of rotationally symmetry of the main mirror (8), facing to the main mirror (8), and reflecting the primary reflected light (13) as secondary reflected light (14) to condense it at the point of view. It also has a transparent case (11) supporting the main mirror (8) and the sub-mirror (10), and transmitting the incident light (12).