| 摘要 |
<p>PROBLEM TO BE SOLVED: To eliminate reduction in resolution in a distant point of a scanning monitoring area, and to reduce a noise quantity of respective pyroelectric elements by forming the arranging directional length of distant point side pyroelectric elements in a pyroelectric element row shorter than the near point side, and forming the light receiving areas in the almost same. SOLUTION: A pyroelectric element row L is arranged in its slant attitude on a wall surface in the vicinity of the ceiling of a gymnasium so as to be turnable with a vertical directional shaft as a fulcrum. In pyroelectric elements E1 to E8 , the arranging directional length X is formed so that the 1CH side existing at a near point successively becomes longer than distant point side 8CH. At the same time, the light receiving areas (the surface areas) of the pyroelectric elements E1 to E8 are wholly equally constituted. That is, when the longitudinal directional and lateral directional lengths of the pyroelectric elements E1 to E8 are denoted by X1 to X8 , Y1 to Y8 , the length X1 to X8 of the pyroelectric elements E1 to E8 and the light receiving areas (X1×Y1 ) to (X8×Y8 ) are constituted so as to become [X1 >X2 ...>X8 , and (X1×Y1 )=(X2×Y2 )=...=(X8×Y8 )].</p> |
