| 摘要 |
<p>PURPOSE:To obtain an inexpensive human body detecting sensor, etc., which is small in size, free from noise, and excellent in reliability. CONSTITUTION:A substrate is fixed to the upper surface of a piezoelectric element 11 and supports a chopper element 4 at the front end of its elastic deforming section which makes elastic vibrations in a torsional vibration mode. The element 4 is constituted by arranging a plurality of stripe-like non- transmitting sections composed of a material which does not transmit infrared rays and having a fixed width W at regular intervals on the surface and rear of an infrared-ray transmitting section 8 in such a way that the positions of the sections on the surface of the section 8 are shifted from those on the rear. A pyroelectric sensor 2 is positioned below the element 4. When the element 11 is driven, the element 4 rotates and the amount of the infrared rays made incident to the sensor 2 changes.</p> |
