Ernst Leitz G.m.b.h.

Ernest Leitz Gmbh

Walter Bletz

Werner H Holle

Rolf Magel

Apparatus for storing a voltage analogous to an exposure parameter in photographic cameras with an electronic timer and with electric exposure measurement, having the characteristics that an analog-to-digital converter is provided as the storage unit, containing a digital-to-analog converter, the output voltage of which is fed to a comparator wherein this output voltage is compared with the voltage delivered by the exposure meter part. The signal obtained at the comparator output in the case of voltage identity stops the analog-to-digital converter and the voltage remaining at the output of the digital-to-analog converter controls the respective exposure parameter in the camera.

Apparatus for storing a voltage analogous to an exposure parameter in

Exposure control device for a photographic camera wherein, in a part of the exposure control device, electronic means are provided in order to form, from the luminous density of an object, the film sensitivity, and the preselected time, a voltage analogous to a diaphragm setting, and wherein a storage means is provided for storing this value, the improvement comprising the combination of the following features: A. when the camera release is actuated, the diaphragm begins to operate from an initial position corresponding to the maximum diaphragm opening, a diaphragm path meter coupled therewith operating simultaneously with this diaphragm and yielding a value corresponding to the change in aperture; B. means are provided which compare the value produced by the diaphragm path meter with the stored value and, in case of identical values, or compensation of the values, stop the operation of the diaphragm by a stop member; C. furthermore, means are provided which add the remaining difference value between the formed value and the value formed by the diaphragm path meter to the value corresponding to the preselected time; and D. the open time of the shutter is formed by conventional electronic means in correspondence with the value delivered by the time setter, taking the difference value into account.

Exposure control device for photographic cameras

An electronic device for storing and indicating illumination parameters and for controlling the exposure time for photographic cameras having an exposure meter and a timer. The exposure meter includes an analog/digital converter with a digital storage part having a plurality of binary stages. These various stages correspond to different intensities of illumination of an object. The timer includes a combination of binary ratio reducers and logic gates and these are adapted to be selected by the analog/digital converter or by manual adjustment. A generator produces impulses which control the timer.

Electronic storage, indicator and exposure time control device for

Digital timers for the electronic control of a camera shutter having a pulse generator and a number of binary dividers each associated with a resistor, the total of these resistors performing a digital to analog conversion and being connected to a common point. The potential of the common point being representative for the number of the binary dividers being in '1' state. A comparator actuating a shutter solenoid when the potential of the common point reaches a predetermined value. All the resistors having the same conductance so that at those times corresponding to powers of 2 (reference timing series) values of potential are formed, which correspond to the logarithm of the time obtained.

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Braunfels, Germany

Walter Bletz