Photographic camera with exposure-measuring device

Claim 1

In a photographic camera having a housing, a shutter release means mounted on the housing, exposure time and film sensitivity controls mounted on the housing and an interchangeable objective lens assembly mounted on the housing having a spring diaphragm with an aperture control, the provision of an exposure measuring device mounted on the housing including: a. a source of supply voltage, b. a photoelectric cell disposed in the path of rays passing through the objective lens and connected in circuit with the source of supply voltage, c. an adjustable resistive means connected in a balancing circuit with the photoelectric cell and influenced by the exposure time and film sensitivity controls of the camera, d. an indicating means connected in circuit with the resistive means and the photoelectric cell and adapted to indicate the state of balance of the balancing circuit, e. opening means for holding the diaphragm in a fully open position, f. diaphragm setting means actuable by the shutter release to move the diaphragm away from the fully open position to an aperture required for accurate exposure g. a stop moveable by a stop-setting member adapted to influence the reading of the indicating means which stop is connectable with the diaphragm setting means when the shutter release is operated, to define at balance the required aperture and h. switch means adapted to selectively disengage or engage the diaphragm setting means from the stop and to connect or disconnect the diaphragm to the aperture control whereby exposure measurement is enabled at a working aperture preset by the aperture control or at maximum aperture automatically closeable to a measured value respectively.