REFLECTIVE COLLECTION-TYPE LIGHT RECEIVING UNIT

摘要

PROBLEM TO BE SOLVED: To provide a reflective collection-type light receiving unit which can be made compact, and in which the light reception/photoelectric conversion efficiency of a light-receiving element can be enhanced while preventing corruption of the light-receiving element due to condensation of powerful light such as direct sunshine.SOLUTION: The reflective collection-type light receiving unit has a light-receiving element 3 which receives spatial light superimposing an information signal, that is reflected and condensed via a concave mirror having a focus. The light-receiving element 3 is disposed on the central axis line of the concave mirror passing through the focus on the inside thereof so that its light-receiving surface 3a faces the mirror face side of the concave mirror. The concave mirror is formed as a partial concave mirror 2 obtained by cutting a part of a regular concave mirror having a focus on the central axis line.