| 摘要 |
PROBLEM TO BE SOLVED: To provide a spot light source device equipped with a structure to surely detect light quantity changes of the inner light source with a simpler constitution and to maintain light quantity of illumination light constant. SOLUTION: For the purpose of light quantity control of illumination light (L) which has passed through a variable aperture (112), a monitor (140) is installed in a space specified by the variable aperture (112) and an emitting port (22), and is installed at a position deviated from the optical path of the illumination light (L). In order to detect the stray light component (R1) which cannot be utilized as the illumination light (L) as a monitor light of light quantity change detection of the illumination light (L), a monitor (140) can utilize efficiently illumination light taken out from the emitting port (22). Moreover, since a part of the illumination light is not utilized as the monitor light, the light quantity control that is added with a loss share of the monitor light becomes unnecessary. COPYRIGHT: (C)2007,JPO&INPIT |
