Photographic copying arrangement with automatic diaphragm control

Claim 2

Photographic arrangement for furnishing copies of an original, comprising, in combination, a source of illumination furnishing light travelling along a predetermined path; diaphragm means positioned along said predetermined path and having at least one movable element for controlling the passage of light therethrough; first and second solenoid means operable in phase opposition and coupled to said movable element for controlling the position thereof in response to activation signals; means mounting said original in said predetermined path; photosensitive means arranged following said original in the direction of light propagation along said predetermined path, for furnishing a photo-transducer output signal varying as a function of light impinging thereon; and circuit means connected to said photosensitive means and said first and second solenoid means for furnishing said activation signals only to said first solenoid means in response to phototransducer output signals indicative of a required increase of light through said diaphragm means and only to said second solenoid means in response to phototransducer output signal indicative of a required decrease of light through said diaphragm means.

Claim 3

Photographic arrangement as set forth in claim 1, wherein said first and second solenoid means comprise first and second rotary magnet means, and gear means intercoupling said first and second rotary magnet means in such a manner that the direction of rotation of said first rotary magnet means is opposite to the direction of rotation of said second rotary magnet means.

Claim 4

Photographic arrangement as set forth in claim 2, wherein said diaphragm means has a first and second movable element, respectively coupled to said first and second rotary magnet means.

Claim 5

Photographic arrangement as set forth in claim 3, wherein said circuit means comprise reference signal furnishing means; differential amplifier means connected to said reference signal furnishing means and said photosensitive means for furnishing a difference signal corresponding to the difference between said reference signal and said phototransducer output signal; and additional circuit means connected to the output of said differential amplifier means, for furnishing said activation signals in response to said difference signal.

Claim 6

Photographic arrangement as set forth in claim 4, wherein said photosensitive means comprise a photosensitive element furnishing a photocurrent corresponding to the light impinging thereon; and current-voltage converter means connected to said photosensitive element for converting said photocurrent into a corresponding output voltage, said output voltage constituting said phototransducer output signal.

Claim 7

Photographic arrangement as set forth in claim 5, further comprising lead network means connected between the output of said current-voltage convertor means and the input of said differential amplifier means, for compensating for the mass moment of inertia of said rotary magnet means and said first and second movable elements.

Claim 8

Photographic arrangement as set forth in claim 4, wherein said reference signal furnishing means comprise first reference signal furnishing means furnishing a first reference signal adapted to effect complete closure of said diaphragm means, second reference signal furnishing means furnishing a second reference signal indicative of the desired exposure, and switching means alternately connecting said first and second reference signal furnishing means to the input of said differential amplifier means.

Claim 9

Photographic arrangement as set forth in claim 7, wherein said first reference signal furnishing means comprise means connecting said input of said differential amplifier to ground potential.

Claim 10

Photographic arrangement as set forth in claim 8, wherein said second reference signal furnishing means comprise adjustable second reference signal furnishing means.

Claim 11

Photographic arrangement as set forth in claim 4, further comprising first and second additional differential amplifier means each having an output connected to a corresponding one of said rotary magnet means, each having a direct input and an inverting input; further comprising means connecting the output of said differential amplifier means to the direct input of said first additional differential amplifier means and the inverting input of said second additional differential amplifier means.

Claim 12

Photographic arrangement as set forth in claim 10, wherein said difference signal has a first polarity indicative of required diaphragm opening and a second polarity indicative of required diaphragm closing; further comprising first diode means connected to said first additional differential amplifier means for suppressing all difference signals having said second polarity and second diode means connected to said second additional differential amplifier means for suppressing all difference signals having said first polarity.

Claim 13

Photographic arrangement as set forth in claim 11, further comprising a first voltage source for furnishing a first voltage; a second voltage source for furnishing a second voltage substantially exceeding said first voltage; first and second capacitor means respectively connected to said first and second rotary magnet means; first and second charging circuit means respectively connected between said second voltage source and said first and second capacitor means for charging said capacitor means to said second voltage prior to activation of the rotary magnet means connected thereto, thereby furnishing a source of starting energy; and third and fourth diode means respectively connected from siid first and second rotary magnet means to said second voltage source, each for effecting a rapid current decay in the corresponding one of said rotary magnet means.

Claim 14

Photographic arrangement as set forth in claim 1, wherein said diaphragm means are positioned prior to said original along said predetermined path; further comprising reflecting shaft means positioned between said diaphragm means and said original along said predetermined path.

Claim 15

Photographic arrangement as set forth in claim 1, further comprising means for deriving a test quantity of light for said photosensitive means mounted along said predetermined path following said original in the direction of propagation of light.

Claim 16

Photographic arrangement as set forth in claim 14, wherein said means for furnishing a test quantity of light comprise partially transmissive mirror means.

Claim 17

Photographic arrangement for furnishing copies of an original, comprising, in combination, a source of illumination furnishing light travelling along a predetermined path; diaphragm means positioned along said predetermined path and having at least one movable element for controlling the passage of light therethrough; first and second solenoid means operable in phase opposition and coupled to said movable element for controlling the position thereof in response to activation signals, said first and second solenoid means comprising first and second rotary magnet means, and gear means intercoupling said first and second rotary magnet means in such a manner that the direction of rotation of said first rotary magnet means is opposite to the direction of rotation of said second rotary magnet means; means for mounting said original in said predetermined path; photosensitive means arranged following said original in the direction of light propagation along said predetermined path, for furnishing a photo-transducer output signal varying as a function of light impinging thereon; and circuit means Connected to said photosensitive means and said first and second solenoid means for furnishing said activation signals in dependence on said phototransducer output signal.

Claim 18

Photographic arrangement for furnishing copies of an original, comprising, in combination, a source of illumination furnishing light travelling along a predetermined path; diaphragm means positioned along said predetermined path and having at least one movable element for controlling the passage of light therethrough; first and second solenoid means operable in phase opposition and coupled to said movable element for controlling the position thereof in response to activation signals, said first and second solenoid means comprising first and second rotary magnet means, and gear means intercoupling said first and second rotary magnet means in such a manner that the direction of rotation of said first rotary magnet means is opposite to the direction of rotation of said second rotary magnet means; means for mounting said original in said predetermined path; photosensitive means arranged following said original in the direction of light propagation along said predetermined path, for furnishing a photo-transducer output signal varying as a function of light impinging thereon; and circuit means Connected to said photosensitive means and said first and second solenoid means for furnishing said activation signals in dependence on said phototransducer output signal.