| 摘要 |
<p>A miniature passive infrared motion detector contains an optical system, a pyroelectric polymer film and an electronic circuit. The optical system is made of a curved Fresnel lens (3) and an elongated wave guide having reflective inner surfaces (1, 4). This affords a very wide field of view by the optical system with the energy (9) of an intruder, for example, focused to a small point on the polymer film (8) which is also curved with the same radius as the lens (3) and has two interdigitized electrodes (6, 7) on the rear surface and one uniform electrode (33) on the front surface. The front electrode (33) is covered with infrared absorbent material. The electronic circuit contains a differential amplifier (14) and a threshold network (22).</p> |
