Automatic sensitivity controller for electronic still camera

An automatic sensitivity controller for an electronic still camera which performs flash photography, said automatic sensitivity controller comprising:

• an image pickup device;
• distance metering means for measuring the camera-to-subject distance;
• a variable-gain amplifier circuit having a control terminal and amplifying a video signal supplied from said image pickup device at a gain determined in response to a control signal applied to said control terminal;
• a gain control means for applying a control signal relating to a measured value of the camera-to-subject distance to said control terminal, wherein said control signal output from said gain control means is a dc-voltage signal, said gain control means having:
• a control voltage producing circuit having a plurality of output terminals through which a plurality of different dc voltages are taken out in parallel with each other;
• a change-over switch for selectively connecting one of said plurality of output terminals to said control terminal of said variable-gain amplifier circuit in response to a change-over control signal;
• and
• switch control means for supplying the change-over control signal relating to the measured value of the camera-to-subject distance to said change-over switch;
• said automatic sensitivity controller further comprising:
• an aperture device for adjusting the quantity of light introduced to said image pickup device;
• aperture value calculating means for obtaining an aperture value by dividing an equivalent guide number determined from the gain of said variable-gain amplifier circuit by the measured value of the camera-to-subject distance;
• and
• aperture control means for controlling said aperture device so that the aperture value of said aperture device becomes equal to the aperture value calculated by said aperture value calculating means.