DE2214549

• Main Authors: KONISHI, YUICHIRO, MACHIDA, TOKIO, TAGUCHI, TATSUYA, TOKIO
• Format: Patent
• Language: English
• Published: 18.07.1974
• Edition: 2
• Subjects: ACCESSORIES THEREFOR; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USINGWAVES OTHER THAN OPTICAL WAVES; APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FORPROJECTING OR VIEWING THEM; CINEMATOGRAPHY; ELECTROGRAPHY; HOLOGRAPHY; PHOTOGRAPHY; PHYSICS

In a shutter control, a photoresistive element whose resistance varies non-linearly with changes in incident light forms part of a voltage divider with a variable resistor. The voltage divider contacts the output of a meter. The resistor, in turn, forms part of an RC circuit that controls the timing of a shutter. Through a movable contact arm, the photoresistive element contacts one of a series of equally spaced tabs that connect to the resistor in a non-linear sequence corresponding to the non-linearity of the photoresistive element. Through a second movable contact arm, the capacitor contacts one of a second series at equally spaced taps that connect to the resistor in a second non-linear sequence. The second sequence corresponds in non-linearity to the non-linearity of a succession of shutter speed adjustments. Adjustments of the shutter speed moves both arms simultaneously so that when the meter reads a predetermined value, the shutter speed corresponds to the light conditions. Adjustment of the film speed marker moves only the second arm.