| 摘要 |
PURPOSE:To arrange so that sufficient enlargement function may be provided to an object field scan-type device by making a lens means in front of a scan line insertable and detachable and almost equalizing a distance between a detector and a light collection means to the focal distance of the light collection means. CONSTITUTION:A window for introducing an infrared ray from a visual field Z to a scan mirror 2 is provided on a cover 6 surrounding an optical system. In addition, in front of the window, a window pane for protection 8 and a rotary body 11 which symmetrically holds an enlargement lens 9 with a shaft 10 set in between, are provided. It is possible to selectively arrange the window pane 8 or the enlargement lens 9 by rotating the rotary body. When the enlargement lens 9 is set in front of the window, a microswitch 13 is put in ''ON'' position and at that time, a detection circuit 14 issues an instruction signal, transmitting it to a focal position control circuit 15 which adjusts the position of the lens 3. A detection signal obtained from an infrared ray detector 1 is transmitted to a display device 16 synchronized to the scan mirror 2, through the intermediary of an amplifier 17. Under this constitution, it is possible to carry out an enlarged observation at high resolution even with an object field scan-type optical system. |
