| 摘要 |
PROBLEM TO BE SOLVED: To provide a light source apparatus for illumination, setting a wide range of illuminance continuously from high illuminance to low illuminance, and making highly accurate FB control over illuminance. SOLUTION: Light from a lamp 1 is condensed by a condensing mirror 2 and made incident onto a light modulation filter 3 which changes the size of an aperture to change the quantity of light passage. Part of light passed through the light modulation filter 3 is branched by a quartz plate 5 and made incident onto a photo receiver 6 of an illuminometer. The light emission side of the quartz plate 5 is provided with a light attenuation filter 7 having a prescribed optical transmittance in such a way as to be inserted and removed. An FB control part 21 of a control part 20 rotates the light modulation filter 3 on the basis of signals from the photo receiver 6 and makes such control that illuminance on the surface of an object to be irradiated 10 takes on a set value. A light attenuation filter control part 22 inserts the light attenuation filter 7 in an optical path in the case of controlling illuminance in a region of low illuminance. Even when controlling illuminance in a region of illuminance lower than this, highly accurate control of the illuminance is made without reductions in an S/N ratio. COPYRIGHT: (C)2010,JPO&INPIT |
