Abstract: An analog signal whose value is proportional to scene-light intensity is converted into a multi-bit digital signal of corresponding value. A train of clock pulses is generated, having a repetition frequency greater than the reciprocal of the shortest exposure duration to be establishable by the control system. The digital light-intensity signal is continually totalized during the course of an exposure by a clocked totalizer which operates in synchronism with the train of clock pulses and produces during the course of the exposure a multi-bit digital totalized-light signal. A comparator has a first input at which it receives the totalized-light signal and a second input at which it receives a digital total-required-light signal. The latter signal is furnished by an addressable storage which stores a plurality of total-required-light signals of different respective values, corresponding to different exposure programs.

Abstract: A shutter mechanism alternates between an exposure phase and a reflex phase. In the reflex phase it reflects incident scene light onto a light-sensitive stage which generates a light-indicating signal. A first control pulse is generated at the start of the reflex phase, and a second control pulse at the end of the reflex phase. An integrating circuit receives the first pulse and during the reflex phase generates an integral signal dependent upon the time integral of the light-indicating signal. A signal-transmission switch is operative in response to the second pulse for transmitting the integral signal to a signal-storing stage. The signal from the signal-storing stage is used as the feedback signal to a negative-feedback control arrangement for the camera diaphragm. This feedback signal is dependent not only upon scene light but also the duration of the reflex phase.

Abstract: An apparatus is described for effecting scene-brightness-dependent control of the duration of the flash produced by a flashbulb flash unit having at least one flashbulb. The apparatus includes a housing so configured and dimensioned that it can be pushed over and onto the flashbulb flash unit. The housing is provided with at least one controllable-transparency optical unit located to occupy the position in front of the flashbulb of the flash unit when the housing has been pushed into place over the flash unit. The housing furthermore contains an automatic scene-brightness-dependent flash-duration control circuit connected to the optical unit and operative for controlling the duration of the flash produced by the flashbulb by keeping the optical unit transparent for a scene-brightness-dependent exposure interval and then automatically rendering the optical unit non-transparent.

Abstract: The camera has a shutter release, a shutter, a device responsive to activation of the release for performing a retarded opening of the shutter, and a device operative when activated for causing the shutter to close. The exposure duration is controlled by an exposure control circuit. When the scene brightness level is within a first range, the automatically selected exposure durations are so short that, during a substantial part of the exposure, the shutter is in the process of changing from its closed to its fully open state. When the scene brightness level is within a second range, the automatically selected exposure durations are so long that, during a substantial part of the exposure, the shutter will already be in its fully open state.

Abstract: A scene-pause counter, a scene-production counter, and a repetition counter are connected in a series. Each counter furnishes its count to an associated comparator which also receives a signal from an addressable read-only memory. Pulse trains are applied to the counters. When a comparator in the series detects coincidence, it initiates counting by the next counter. When the last comparator in the series detects coincidence it can restart the first counter. A program-selector switch causes different address signals to be applied to the memory, resulting in different operations of different durations, in different combinations and sequences. This makes possible projection or exposure of single frames or series of frames with intermediate pauses between the projection or exposure of successive frames or series of frames, as well as repetitions of such combinations of operations.

Abstract: A first voltage divider comprised of a fixed resistor and a light-dependent resistor, and a second voltage divider comprised of two fixed resistors are both connected across the camera battery. A variable attenuator is located in the path of scene light incident upon the light-dependent resistor and is coupled to the diaphragm-setting selector for coordinated movement. Two transistors of complementary conductivity type have their bases connected in common to the first voltage-divider tap and their emitters connected in common to the second voltage-divider tap. Each one of two light-emitting diodes is connected in the collector-emitter circuit of a respective one of the two transistors. An adjustable resistor is connected between the bases and emitters of the transistors for establishing the potential difference across the two voltage-divider taps at which the transistors become conductive and the diodes become illuminated.

Abstract: The output of a bridge circuit which is unbalanced when the quantity of light falling on a light-sensitive element is less than or more than a predetermined light quantity is applied to a differential amplifier circuit whose output varies from a minimum amplitude to a maximum amplitude. The output of the differential amplifier is connected to a first and second threshold circuit whose threshold values are symmetrical to the output value of the differential amplifier when the bridge is in balance. The gain of the differential amplifier is adjusted so that the differential output signal has an amplitude exceeding the first threshold value and less than the second threshold value for variations of light within an allowable range. Within this range the first threshold circuit furnishes an output signal and the second threshold circuit does not.

Abstract: A photographic camera is provided with means for detachably mounting either a flashbulb flash unit or an electronic flash unit. The camera includes a piezoelectric transducer mechanically activatable for generating voltage impulses. When the flashbulb flash unit is mounted on the camera, the voltage impulses are directly applied across the terminals of the flashbulb. There elapses a certain time interval between the start of flashbulb firing and the development of maximum flashbulb output illumination. This time interval is taken into account in the design of the shutter-activating mechanism. When, instead of the flashbulb flash unit, the electronic flash unit is mounted on the camera, the voltage impulses generated for flashbulb firing are utilized to initiate operation of the electronic flash unit. Because the flash tube of the unit develops maximum output illumination more quickly than does a flashbulb, a time-delay circuit is utilized to effect compensation.

Abstract: The pulse repetition rate of a pulse generator furnishing pulses to a stepmotor which opens and closes the aperture in response to signals indicating that the quantity of light falling on the film is too little or too much respectively, is varied so that the aperture size is changed more rapidly when the difference between the desired and the actual quantity of light falling on the film is great, and is changed more slowly as the quantity of light falling on the film approaches the desired light quantity.

Abstract: A single operating switch replaces the main switch connecting the diaphragm control means to the battery and the release switch activating the film transport. All camera circuits are directly connected to the battery when the main operating switch is closed. An electronic switch is connected in series with the film transport motor and is closed only upon receipt of a control signal. In a first embodiment the control signal is furnished by a timing circuit after a predetermined time interval following the activation of the main operating switch. In a second embodiment the control signal is furnished by a NAND-gate which has a first input which receives a "1" signal while the diaphragm is being adjusted and a second input which receives a "1" signal while the electronic switch is open. The NAND-gate thus furnishes a "1" signal to the electronic switch causing it to be conductive at all times except when the initial adjustment of the diaphragm takes place.

Abstract: The motor is comprised of two stators arranged coaxially. Each stator is formed of a first pole teeth plate and a second pole teeth plate interdigitated with each other. The first plates are arranged back-to-back and angularly offset relative to each other by half the pole pitch of either stator. The first pole teeth plates are identical. Each first plate has a first engaging portion cooperating with a second engaging portion of a stator housing fixedly connected to the second plate of the same stator to fix the relative angular positions of the components. On each first plate, the first engaging portion and the neighboring tooth of the same plate define an angle which is bisected by a line relative to which there are symmetrically disposed on the same plate at least two third engaging portions. In the assembled motor, the third engaging portions of one first plate congruently overly the third engaging portions of the other first plate.

Abstract: The exposure control circuit of the camera requires a supply voltage which must have an amplitude exceeding a predetermined minimum amplitude. The camera battery is subject undesired decreases in battery output voltage. A transverter circuit has an input connected to the battery and in response to the battery output voltage furnishes a DC output voltage to the exposure control apparatus when the battery output voltage has an amplitude less than the predetermined minimum amplitude. A control circuit is responsive to the voltage applied to the exposure control apparatus and controls a controllable impedance connected between the transverter input and the battery so that the supply voltage applied to the exposure control apparatus remains constant at a value just exceeding the predetermined minimum amplitude when the battery output voltage is too low and disconnects the transverter circuit from the battery when the battery output voltage exceeds the predetermined minimum amplitude.

Abstract: Pressing of the camera release button causes start of the film transport and automatic setting of the diaphragm for a normal exposure. When fade-over switch is closed, a forward-reverse counter is started. When the count on the counter reaches 31, a first AND-gate switches a first JK flip-flop to a second state wherein an additional resistor is inserted in the normally balanced diaphragm control circuit thereby unbalancing same and causing the closing of the diaphragm to commence. When the count on the counter reaches 63, another AND-gate switches additional JK flip-flops for reversing both the film transport and the counting direction of the counter. When the counter has counted down to a predetermined number, further logic circuits cause a stoppage of the film transport and stopping and resetting of the counter so that reactivation of the release button automatically starts the fade-in.

Abstract: A pair of contacts of a relay energizes the driving circuit for the film drive motor when closed. The coil operating the contacts is connected in series with the emitter of a transistor whose base is connected to the battery upon closing of the camera activating button. Zener diode connected between the base of the transistor and the relay contacts. Closing of the contacts thus energizes the motor driving circuit and also connects the Zener diode into the base-emitter circuit of the transistor, thereby decreasing the base voltage and increasing the emitter-collector resistance so that current through the coil is decreased to the holding current.

Abstract: A light-sensitive element is connected to a capacitor to vary the charging rate of the capacitor in accordance with the light falling on the light-sensitive element. The emitter-collector circuit of a switching transistor is connected in series with the light-sensitive element. The base of the transistor is pulsed by an astable multivibrator which furnishes a pulse sequence having a pulse repetition rate which exceeds the reciprocal of the smallest exposure time. The pulses in the pulse sequence have a pulse width determined by the selected one of a plurality of resistors. The selector switch inserting the selected one of the resistors into the astable multivibrator circuit is coupled to selector means which select one of a plurality of exposure factors as for example the aperture size. The electronic switch is conductive, permitting charging of the capacitor only during the pulse duration. The charging rate of the capacitor can therefore be adapted to the particular aperture size, film sensitivity, etc.

Abstract: A camera has a step motor for stepwise adjustment of the value of an exposure factor. When the value of the exposure factor differs from the desired value a pulse generator furnishes a series of pulses to a ring counter which in turn connects each of the energizing windings of the step motor to a reference potential. The step motor rotates until the desired exposure factor value has been achieved and the pulse sequence ceases. A transistor is connected between the battery and the second terminals of all the windings and is maintained in a conductive state only in the presence of the pulses from the pulse generator. When the exposure factor is at the desired value and no further rotation of the step motor is required all windings are deenergized therefore decreasing the power loss in the motor.

Abstract: Pulses are furnished which each indicate transport of a frame. The pulses are counted on a BCD counter. Selected outputs of the counter are connected to the inputs of coupling stages, each including a JK flip-flop. Each flip-flop changes state for a predetermined count on the counter. When each flip-flop changes state, a corresponding indicator lights up, thereby furnishing an indication to the photographer of how many frames have been transported.

Abstract: A bridge circuit contains a photoelectric resistor positioned behind the diaphragm and thus having a resistance varying as a function of the light falling on the film. A second arm of the bridge circuit contains a resistor. The bridge circuit output is connected to the inputs of a differential amplifier whose output controls a step motor which adjusts the size of the aperture until the bridge is balanced. For fade-out, an additional resistor is inserted in the second arm by opening a short-circuiting switch, thus causing the bridge to become unbalanced and the step motor to change the aperture until it is again in balance. This balance will take place at a predetermined low illumination suitable for fade-out. Closing the switch will result in fade-in, namely an opening of the aperture until the circuit is again in balance. The output signal from the bridge circuit thus controls the aperture even during fade-in and fade-out.

Abstract: A single light-sensitive element serves to furnish a signal for setting the aperture prior to the exposure time and to control the exposure time. Prior to the exposure time a first and second threshold stage furnish a first and second threshold output signal respectively when the light is in a first and second predetermined range. The first and second threshold output signals are applied to the control input of a first and second D flip-flop. The output of the D flip-flop varies as a function of the signal at the control input only in the presence of a gating signal. The gating signals are applied to the D flip-flops only prior to the exposure time. The outputs of the first and second D flip-flops are applied to an exclusive OR-circuit whose output is applied to aperture control means which vary the size of the aperture in dependence on the logic circuit output signal. The D flip-flop maintains its output after removal of the gating signal thereby maintaining the aperture size during exposure.

Abstract: A photographic camera includes a diaphragm arrangement comprised of at least one body of liquid crystal positioned in the path of light entering the camera. The size of the opening of the diaphragm arrangement is changed by changing the transparency of at least one portion of the one or more bodies of liquid crystal.