| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a pyroelectric infrared sensor that can detect a detection object if the object does not move, further define a detection range and ranges other than the range strictly, and that can avoid erroneous detection and non-detection.SOLUTION: The pyroelectric infrared sensor comprises: a pyroelectric element 1; a monitoring frame 20 arranged in front of the pyroelectric element 1 and for limiting an infrared incident range to the pyroelectric element 1; and a re-detection device performing an operation required for performing re-detection when the pyroelectric element 1 stops detecting a detection object. The re-detection device includes: a blocking plate arranged overlapping on the monitoring frame 20 and blocking infrared in a range of incidence limit by the monitoring frame 20; and an actuator for moving the blocking plate. The pyroelectric infrared sensor further comprises a control unit for controlling the operation of the actuator using a detection signal of the pyroelectric element 1 as an input, which control unit ignores a detection signal outputted from the pyroelectric element 1 in re-detection operation by the re-detection device.</p> |
