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AssigneeAsahi Seimitsu Kabushiki Kaisha
InventorsMasayuki Arai, Terumi Ogasawara, Tohru Shikano
Estimating the term…
A control circuit for automatically opening and closing the diaphragm of the objective lens of a closed circuit television (CCVT) camera including a variable gain inverting amplifier for amplifying and inverting video signals from the camera, a voltage doubler and rectifier with an adjustable capacitor coupled to the output of the inverting amplifier, a voltage level shifter coupled to the output of the voltage doubler for lowering signals output therefrom by a predetermined voltage, a power supply for providing bias voltage to said control circuit, an intermediate voltage supply circuit for providing a signal reference voltage to said circuit which is intermediate to the value of said bias voltage, and a comparator circuit for comparing the intermediate voltage with the signal output from said level shifter and opening or closing the diaphragm based on the results of the comparison.
An automatic control circuit for opening and closing the diaphragm of the objective lens for a video camera comprising:
Dependencies are inferred from the claim text.