SENSITIVITY CORRECTION METHOD FOR INFRARED-RAY IMAGE PICKUP DEVICE

摘要

PURPOSE:To reduce uneven brightness and to obtain a video image with high accuracy by obtaining on/off state periodically depending on the control of an applied voltage to a liquid crystal shutter and applying periodic offset correction sequentially. CONSTITUTION:A liquid crystal shutter 31 is arranged in an optical path of the converging and image forming optical system and turned on or off by the control of an applied voltage. The liquid crystal shutter 31 is turned on/off to defocus an incident radiant ray and make it incident in a multi-element type infrared ray sensor 30 with the light scattering effect of the liquid crystal in the off-state to obtain an offset correction data periodically and the offset is corrected by an offset correction data. Thus, the video image with less uneven brightness is always obtained.