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US 4,365,272 AGranted
Television camera apparatus having automatic gain-selecting unit
AssigneeNippon Electric Co., Ltd.
InventorKiyotake Nagai
Life of this patent
Estimating the term…
Abstract
A television camera is provided with an automatic gain selecting unit which is responsive to the iris value of the lens attached to the camera. The automatic gain selecting unit includes a comparator for determining when the camera lens-iris operates within a medium "window" range, a counter for counting upwardly or downwardly when the lens-iris operates outside of the window range, and a decoder for outputting a control signal to a gain selecting amplifier to adjust the gain thereof, in response to the operation of the counter.
Claims5
A television camera apparatus comprising:
- a lens device including a servo-controlled lens-iris and means for producing a variable value signal according to the iris value of said lens-iris;
- pick-up means adapted to receive the light passed through said lens device for generating a video signal in response to said light;
- a gain-selecting amplifier for amplifying said video signal;
- means for detecting a signal level of the video signal amplified by said gain-selecting amplifier;
- means for controlling the iris value of said lens-iris in response to the signal level detected by said detecting means;
- means for determining whether said iris value signal lies within a range of predetermined levels corresponding to a predetermined range of iris values to produce an output when said iris value signal falls outside of said range of predetermined levels;
- and
- means for selecting the gain of said gain-selecting amplifier according to the output of said determining means such that said iris value signal goes back within said range of predetermined levels.
5 more elements
Dependencies are inferred from the claim text.