AUTOMATIC LIGHT CONTROL SYSTEM

摘要

AUTOMATIC LIGHT CONTROL SYSTEM A system is disclosed for automatically controlling the light intensity of a light source as a function of the amount of light received by a photosensor. In a preferred embodiment the light source illuminates a reference background which, in turn, reflects the light incident thereon to a photosensor in a video camera. In response to this reflected light, the photosensor produces a video signal which is proportional to the amount of light reflected thereon. A first means is responsive to the reception of the video signal over a preselected period of time for providing a first signal which is proportional to the amount of reflected light received by the photosensor over that preselected period of time. A second means is responsive to the first signal for generating a control signal to automatically cause an adjustable power supply to change the voltage applied to the light source as a function of the amplitude of the control signal.