Patent attributes
An optical path change element includes a first facet that receives incidence of light beams outgoing from outgoing portions of a first optical element, a second facet that has a predetermined radius of curvature and is provided with a reflection face to reflect the incident light beams from the first facet, and a third facet causing the light beams reflected on the reflection face to outgo to the incident portions of a second optical element. The second facet has protruded faces spaced from the reflection faces. Virtual planes tangent to the protruded faces are defined. At least one of the virtual planes covers the reflection face without being tangent to the reflection face and being parallel with a tangent plane at an arbitrary point of the reflection face.
