| 摘要 |
<p>PURPOSE:To provide an infrared human body detector which surely detects the passage of a human body inside a detecting area, does not malfunction even with such causes of malfunctioning as fluctuation of air caused by small animals and/or winds, has a simple structure and can be manufactured at low cost. CONSTITUTION:Four detecting elements constituting an infrared detector are arranged in cruciform With the adjacent ones having different polarities, and four detecting areas E1-E4 determined by the relative positions of the light collector of a light collecting portion and the detecting elements, are arranged with the lowest detecting element E1 located beneath the ground G, and the bottom sides of two E2, E3 of the remaining three detecting areas located above and near the ground G, and the remaining detecting area E4 located above the ground G. The light collecting portion includes a band-pass amplifier, a wind comparator circuit, a timer circuit, and a pulse counting circuit, the band- pass amplifier comprising band-pass filters.</p> |
