| 摘要 |
PURPOSE:To improve a visual field characteristic by using an infrared filter of an infrared ray detector as an auxiliary lens for condensing infrared ray. CONSTITUTION:As for an infrared filter 12 of an infrared ray detector 11, its infrared ray condensing lens 13 side is formed to a convex curved surface, and an infrared ray condensing system is formed by combining it with the infrared ray condensing lens 13. The infrared ray condensing lens 13 and the infrared filter 12 have functions as a main lens and an auxiliary lens, respectively. In such a way, the visual field characteristic is improved, and the visual field interference of the sun and the moon can be made as small as possible by vapor-depositing a transparent multilayer vapor-deposited film against an infrared ray, on both faces of the infrared filter 12 and making it have an infrared filter characteristic. |
