| 摘要 |
<P>PROBLEM TO BE SOLVED: To prevent a crosstalk that the light directly enters a light receiving element from a light source. <P>SOLUTION: In the optical system including at least one light source, at least one light receiving element and a light flux separating means for transmitting or reflecting the projection light flux from the light source toward an incidence/emission port and reflecting or transmitting received light flux that is incident from an incidence/emission port, to the side of the light receiving element, the at least one light source and the at least one light receiving element are positioned on the same side relative to the light flux separating means. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
