| 摘要 |
PURPOSE:To raise the detection accuracy and the reliability, and to realize to make the titled photosensor small in size, by placing an electric chopper element in an arrival side, of a pyroelectric element. CONSTITUTION:This sensor is formed by containing body part in a case consisting of a base 1 which consists of, for instance, aluminum, and a sealed crown. On a sealed crown 2, an incident window 3 of a light beam is provided. The body part is formed by placing lamellately a glass window 4, an electric chopper element 5, a supporting plate 6, an optical filter 7, a radiation plate 8, and a pyroelectric element 9, in order from the front, namely, the side where the light beam arrives. The electric chopper element 5 is formed by enclosing a liquid crystal 13 between two pieces of transparent electrode plates 11, 12 which have been placed opposingly through a ring-shaped spacer 10. |
