# US 4,398,813 A · Photographic camera > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 4,398,813 A - Document ID: US4398813A - Status: Granted - Kind: A - Application number: 06/303,016 - Filed: 1981-09-17 - Granted: 1983-08-16 - Earliest claimed: 1980-09-29 - Assignees: Agfa-Gevaert - Inventors: Eduard Wagensonner; Karl Wagner; Bernhard von Fischern - Web page: https://patentgrep.com/patent/US4398813A ## CPC - G03B 7/097: for control of both exposure time and aperture - G03B: APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR (optical parts of such apparatus G02B; photosensitive materials or processes for photographic purposes G03C; apparatus for processing exposed photographic materials G03D) ## Abstract A photographic camera with automatic setting of diaphragm and exposure time. A light sensitive circuit generates pulses and is connected to a diaphragm counting stage for comparing signals from the light sensitive circuit with preset signals in the diaphragm counting stage and for providing a stop pulse to an electromagnetic diaphragm setting stage. A counter is connected to a pulse generator and to the diaphragm counting stage in a stop control connection. A start control provision connects the output of the diaphragm counting stage to an exposure time forming stage. The exposure time forming stage can be connected to the counter for providing automatic setting of the time determining part of the exposure time forming stage depending on the counting state of the counter. A shutter opening member can be connected to the diaphragm counting stage for receiving a control signal for the release part of the shutter opening member. ## Claims ### Claim 1 A photographic camera having an aperture diaphragm, a shutter control means and a diaphragm setting device, said diaphragm setting device comprising a light-sensitive circuit generating pulses; an electromagnetic diaphragm setting stage; a diaphragm counting stage connected to the light-sensitive circuit for comparing signals from the light-sensitive circuit with preset signals and for providing a stop pulse to the electromagnetic diaphragm setting stage; a pulse generator; a time counter connected via a stop control connection to the pulse generator and to the diaphragm counting stage; and said shutter control means comprising an exposure time forming stage connected via a start control connection to the output of the diaphragm counting stage. ### Claim 2 (depends on 1) The photographic camera according to claim 1 wherein the exposure time forming stage is connected to the counter for providing automatic setting of the time determining part of the exposure time forming stage depending on the counting stage of the counter. ### Claim 3 (depends on 2) The photographic camera according to claim 2, said shutter control means comprising a shutter opening member connected to the diaphragm counting stage for receiving a control signal for the shutter opening member. ### Claim 4 (depends on 3) The photographic camera according to claim 3 further comprising connection means between the exposure time forming stage and the counter for automatically adjusting the value of the time determining part of the exposure time forming stage depending on the counting value of the counter. ### Claim 5 (depends on 4) The photographic camera according to claim 4, said aperture diaphragm being connected to the electromagnetic diaphragm setting stage for providing a light dependent and automatic setting of the diaphragm. ### Claim 6 (depends on 4) The photographic camera according to claim 4 wherein the exposure time forming stage is connected for being turned on after the setting of the diaphragm. ### Claim 7 (depends on 4) The photographic camera according to claim 4 further comprising an amplifier connected to the electromagnetic diaphragm setting stage, and wherein the diaphragm counting stage comprises a reversible counter which can be set to a certain counting contents and the transfer output of which is connected to the amplifier. ### Claim 8 (depends on 4) The photographic camera according to claim 4 wherein the stop control connection comprises an AND gate having its output connected to the clock input of the time counter where the pulse generator provides a timing pulse and is connected to an input of the AND gate, where the cycle period is small compared to the shortest time for forming the diaphragm provided by the diaphragm counting stage; a memory flip-flop having its output Q connected to the second input of the AND gate and having its reset input R connected to the transfer pulse output of the diaphragm counting stage for switching off the memory flip-flop; and further comprising a starting switch connected to the light sensitive circuit and to the clock input of the memory flip-flop. ### Claim 9 (depends on 8) The photographic camera according to claim 8 wherein the memory flip-flop is D-flip-flop. ### Claim 10 (depends on 4) The photographic camera according to claim 4 wherein the exposure time forming stage comprises a digital-analog converter stage connected to an output of the counter; a voltage-current converter connected to the output of the digital-analog converter stage; a capacitor connected to the voltage-current converter; and a memory flip-flop connected to the voltage-current converter and connected to the electromagnetic diaphragm setting stage. ### Claim 11 (depends on 10) The photographic camera according to claim 10 wherein the digital-analog converter is connected with its set input S to the transfer output U of the diaphragm counting stage. ### Claim 12 (depends on 4) The photographic camera according to claim 4 wherein the exposure time forming circuit comprises a digital-analog converter connected to an output of the counter; and a memory flip-flop controlled through its set input S by the output voltage (U.sub.Q) of the digital-analog converter serving as a threshold voltage U.sub.S and having a control input connected to a timing element comprising a capacitor and a resistor. ### Claim 13 (depends on 4) The photographic camera according to claim 4 further comprising a shutter closing magnet; wherein the light sensitive circuit generating pulses is provided as a second pulse generator having an adjustable frequency; wherein the exposure time forming stage comprises a reversible time forming counter connected to the output of the counter and the set input of the reversible time forming counter is connected to the transfer output U of the diaphragm counting stage and the clock input of the diaphragm counting stage is connected to the output of the second pulse generator and where the transfer output U of the time forming counter actuates the shutter closing magnet. ### Claim 14 (depends on 1) The photographic camera according to claim 1 said shutter control means comprising an opening mechanism controlled by the electromagnetic diaphragm setting stage. ### Claim 15 (depends on 1) The photographic camera according to claim 1 said shutter control means comprising a closing mechanism controlled by the electromagnetic diaphragm setting stage. ### Claim 16 A method for controlling the exposure provided by a photographic camera comprising converting light radiation into electrical pulse signals; comparing the pulse signals with a preset count in a diaphragm counting stage; generating a stop pulse upon finding equivalence between the pulse signals and a preset condition; feeding the stop pulse to a diaphragm setting stage; feeding a control signal from the diaphragm counting stage to the release part of a shutter opening member; switching on a counter having a timing pulse generator at about the same time as the diaphragm counting stage; stop-controlling the counter with the output of the diaphragm counting stage; start-controlling an exposure time forming stage with the transfer output of the diaphragm counting stage; and automatically adjusting the value of the time determining member of the exposure time forming stage depending on the counting state of the counter. ### Claim 17 (depends on 16) The method for controlling according to claim 16 comprising feeding the transfer output of the diaphragm counting stage constructed as a reversible counter adjustable to a defined counting state contents via an amplifier to a diaphragm electromagnet. ### Claim 18 (depends on 16) The method for controlling according to claim 16 wherein the counter is switched on by feeding the signal from the timing pulse generator having a cycle period short as compared to the shortest time of formation of the diaphragm of the diaphragm counting stage to the input of an AND gate; feeding the output Q of a memory flip-flop to a second input of the AND gate; feeding the output of the AND gate to the clock input of the counter; switching on the memory flip-flop via its clock input T with a starting switch; and switching off the memory flip-flop via its reset input R through a transfer pulse of the diaphragm counting stage. ### Claim 19 (depends on 16) The method for controlling according to claim 16 further comprising feeding the output of the counter to a digital-analog converter stage; feeding the output of the digital-analog converter to a voltage-current converter; feeding the output of the voltage to current converter to a timing capacitor and to a following memory flip-flop; feeding the signal from the memory flip-flop to an electromagnet. ### Claim 20 (depends on 19) The method for controlling according to claim 19 further comprising feeding the output of the transfer output of the diaphragm counting stage to the set input of the digital-analog converter stage. ### Claim 21 (depends on 16) The method for controlling according to claim 16 further comprising feeding the transfer output of the diaphragm counter stage to the clock input of a second memory flip-flop for controlling the second memory flip-flop, the output of which is connected to a shutter release magnet. ### Claim 22 (depends on 16) The method for controlling according to claim 16 further comprising feeding the output of the counter to a digital-analog converter stage; and feeding the output of the digital-analog converter stage to a memory flip-flop as a control voltage for setting a threshold voltage. ### Claim 23 (depends on 16) The method for controlling according to claim 16 further comprising feeding the output of the counter to a time forming reversible counter; feeding the transfer output of the diaphragm counting stage to the set input of the time forming counter; feeding the output of a second adjustable pulse generator to the clock input of the time forming counter; actuating a shutter closing magnet by way of the transfer output of the time forming counter. ### Claim 24 (depends on 23) The method for controlling according to claim 23 further comprising adjusting the frequency of the adjustable second pulse generator depending on the characteristic course of the diaphragm setting member. ### Claim 25 (depends on 23) The method for controlling according to claim 23 further comprising adjusting the frequency of the adjustable second pulse genrator depending on the sensitivity of the film employed. ### Claim 26 (depends on 16) The method for controlling according to claim 16 wherein the automatic adjusting of the value of the time adjusting member is provided by feeding the output of a second AND gate to the clock input of a bidirectional counter; feeding an input of the second AND gate with the transfer output of the diaphragm counting stage via a second memory flip-flop; and feeding the transfer output of the diaphragm counting stage to the counting direction reversing input of the bidirectional counter; and wherein the switching on of the counter is provided by feeding the output of a third AND gate to the clock input of the bidirectional counter; feeding the output Q of a first D-flip-flop to an input of the third AND gate; feeding the output of the first pulse generator to an input of the third AND gate; switching the clock input of the first D-flip-flop with a starting switch; and feeding the transfer output of the diaphragm counting stage to the reset input R of the first D-flip-flop.