| 摘要 |
<p>PURPOSE:To increase the difference of incidence time of infrared rays to respective pyroelectric elements and to increase the output levels of both pyroelectric elements by composing the direction decision sensor of a couple of pyroelectric elements which are connected in reverse series, a couple lenses corresponding to them, and a light shield plate which inhibits infrared rays passed through the lenses from being incident on elements other than their corresponding pyroelectric elements. CONSTITUTION:The couple of pyroelectric elements 3a and 3b which are connected reversely in series are put in a package 4 to constitute a pyroelectric sensor 1, which generates a negatively large output when a body moves from one element 3a to the other element 3b and a positively large output when the body moves in the opposite direction. Thus, the sensor 1 is constituted, the couple of lenses 2a and 2b are provided at an interval in the array direction of the elements 3a and 3b, and the distance between the lenses is made variable. Further, the light shield plate 6 is provided between the elements 3a and 3b at right angles to the array plane and the infrared rays passed through both the lenses 2a and 2b are made incident on the elements 3a and 3b independently of each other to generate the time difference in timing between the incident infrared rays.</p> |
