| 摘要 |
<p>PROBLEM TO BE SOLVED: To cope with an obstructive act performed against a compound type detector utilizing an infrared sensor and an image sensor. SOLUTION: A sensor cover 30 is provided with a window member 12. A 1st light transmission area on the cover 30 corresponding to an image pickup part 14 and a 2nd light transmission area on the cover 30 corresponding to a pyroelectric element 16 are set so as to entirely or partially overlap with each other, and and any attempt to obstruct infrared detection can be detected as the change of image information. The element 16 can also be arranged at the back of the part 14, and an infrared light receiving field may be set by utilizing a Fresnel lens, etc., without using a mirror 40.</p> |
