| 摘要 |
<p>PURPOSE:To enable efficient execution of a detecting process by interposing a mirror means being movable forward and backward in a straight line and by making it project a light beam onto a detecting surface area. CONSTITUTION:A projection light alpha emitted from a laser diode 13 is applied, through a condenser lens L1, onto a total reflection mirror 14 borne by a mirror bearing body 12. The optical path of the light is bent at an angle at 90 deg. and the light is projected onto a detecting surface area 20, in the form of a parallel beam, from a pinhole 15' of a pinhole mirror 15. When a substance W to be detected is present in the area 20 on the occasion, the optical path of the projection light alpha is interrupted by the substance W and a reflected light beta is not fed back to the photodetector 16 from the mirror 15. The presence of the substance W can be detected from that the reflected light beta is not fed back to the photodetector 16.</p> |
