Automatic iris control means for variable focal length lens system
AssigneeFuji Photo Optical Co., Ltd.
InventorsNaohei Watanabe, Tadaomi Inoue
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Abstract
A servo-motor connected with potentiometers to be balanced is used for controlling the diameter of an iris of a lens system of variable focal length. One potentiometer to be used for detecting the position of control is connected with a plurality of change-over switches by way of different resistors. The change-over switches are changed in response to the change of the focal length to correct the iris with reference to the changed focal length.
Claims4
Means for controlling an iris of a variable focal length lens system comprising a servo-motor, a control potentiometer connected with the servo-motor for input of iris control signal, a position detecting potentiometer connected with the servo-motor to control the servo-motor by the balance made with reference to said control potentiometer, an iris control means connected with said servo-motor to control the diameter of an iris of the lens system, said iris control means being connected with said position detecting potentiometer so that the controlled position of the iris control means is detected by the detecting potentiometer, a plurality of change-over switches connected with said position detecting potentiometer, said switches being changed over in response to the change of the focal length of the lens system, and resistors having different resistance connected in series with said change-over switches, respectively.
Means for controlling an iris of a variable focal length lens system comprising a servo-motor, a control potentiometer connected with the servo-motor for input of iris control signal, a position detecting potentiometer connected with the servo-motor to control the servo-motor by the balance made with reference to said control potentiometer, an iris control means connected with said servo-motor to control the diameter of an iris of the lens system, said iris control means being connected with said position detecting potentiometer so that the controlled position of the iris control means is detected by the detecting potentiometer, a plurality of change-over switches connected with said position detecting potentiometer, said switches being changed over in response to the change of the focal length of the lens system, and resistors having different resistance connected in series with said change-over switches, respectively, said resistors being connected between the detecting potentiometer and the change-over switches.
Dependencies are inferred from the claim text.