| 摘要 |
<p>PURPOSE:To detect a position where a human body exists using a single infrared detector. CONSTITUTION:Effective detection areas 2A-2C having different areas are set in partial detection areas 1A-1C by a condensing unit. When a human body traverses the effective detection areas 2A-2C, far infrared radiation from the human body is detected by an infrared detector. Output from the infrared detector has different frequencies for the effective detection areas 2A-2C. Consequently the existence of human body in any one of the partial detection areas 1A-1C can be detected based on the variation time or frequency of the output.</p> |
