| 摘要 |
<p>PURPOSE:To obtain a heat ray detector which is better in heat ray detection sensitivity and does not cause malfunction easily by increasing the amount of heat rays receivable with a heat ray detector. CONSTITUTION:A heat ray detector includes a lens 3 for condensing light provided at a circumferential surface part 4 of a housing case 1 and a heat ray detector 2 in which photodetecting surfaces 2a are arranged facing each other at least in the housing case 1 to receive heat rays advancing into the housing case 1 transmitted through the lens 3 for condensing. A mirror finished section 1d is provided at a peripheral position ahead of the photodetecting surfaces 2a of the heat ray detector 2 to reflect the heat rays advancing to the peripheral position ahead of the photodetecting surfaces 2a.</p> |
