| 摘要 |
In order to produce an excellent frost protection effect without increasing the size, a crime prevention sensor is so structured that an element unit (21) including sensor elements (15, 23) for transmitting or receiving a detection wave IR is supported on the sensor body (41) such that the horizontal deflection angle and the vertical deflection angle R V can be adjusted, a cover (43) covering the element unit (21) is attached to the sensor body (41), and the center of rotation (10) of vertical deflection of the element unit (21) is shifted downward or upward from the central portion of the element unit (21) in the vertical direction. A recessed portion (56) of the cover (43) recessed from the other portion toward the inside of the cover (43) is formed in a part of the cover (43) corresponding to the part to which the center of rotation (10) of the element unit (21) is shifted through a stepped portion (44). A hood (17) for isolating at least a part of the region where the detection wave IR passes for the sensor element (23) from the sky is provided above and near the center of rotation (10) of the cover (43). |
