| 摘要 |
<p>PROBLEM TO BE SOLVED: To improve the detecting accuracy of object information detecting device for contaminants adhering to the external surface of the front window of a case by detecting the contaminants with light transmitted through the window. SOLUTION: A triangular prism-like projection 30 is provided on the front window 2 of a case 3. Contamination detecting light R emitted from a contamination detecting light emitting section 23 provided in the case 3 is made incident on the window 2 and emitted to the outside from the window 2 while the light R is refracted after the light R is totally reflected by the slope 30a of the projection 30. At the same time, the light R advances toward the external surface of the window 2 and received by means of a light receiving section 29 for detecting contamination incorporated in the case after the light R is again transmitted through the window 2.</p> |
