| 摘要 |
PURPOSE:To enable a large output signal to be always obtained by using a pyroelectric infrared ray sensor element and inserting a differential supplementation between this dual sensor element and an object to be detected. CONSTITUTION:A first element 10a and a second element 10b are constituted by one pyroelectric plate. In front of the light receiving surface of a dual sensor element 10, infrared ray transit restricting plates 11 are arranged and a differential signal supplementation 12 is arranged at approximately central portion of the passage region of the restricting plates 11. When an object to be detected moves to cross the front of the element 10 at an equal speed, output signals (a) and (b) are obtained from the elements 10a and 10b, respectively, by the operation of the supplementation 12. Therefore, a differential signal output OUT(a-b) has an ample output sensitivity even at the center of the displacement of the object to be detected. |
