| 摘要 |
<p>PURPOSE:To enable an infrared sensor device to clearly detect the motions of both persons respectively moving along and perpendicularly to the wall of a room and, at the same time, to prevent the occurrence of a dead angle in the visual field of the sensor. CONSTITUTION:The attitude of a pyroelectric element 2 against a lens 4 is inclined by about 45 deg. from the prior art attitude so that a virtual straight line L connecting two pyroelectric detecting sections 3a and 3b can intersect a horizontal floor at about 45 deg. when the title sensor device 1 is fitted to the vertical wall of the room at. Therefore, movement of persons in a building or room can be suitably detected.</p> |
