US3724946A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Photographic printing arrangement
Assignee: Agfa Gevaert AG
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Filing: 1971-09-20
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Granted: 1973-04-03
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Expires: 1991-09-20
Abstract
Abstract Photographic arrangement for copying an original which includes illuminating means for illuminating the original and timing means for terminating the illumination after a preadjustable time interval corresponding to the density of the original. This photographic arrangement also includes photoelectric transducing means furnishing an illumination signal corresponding to the lighting impinging thereon. Finally, the photographic arrangement also includes energizing means interconnecting the photoelectric transducing means with the timing means so as to vary the energization signal in correspondence with the variations of the illumination signal.
Inventors
- 👤 W Knapp
- 👤 O Schneider
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 12:05
CPC Classifications
G; G03; G03B; G03B27/00; G03B27/72
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
165 words
Photographic arrangement for copying an original, comprising, in combination, illuminating means illuminating said original, the intensity of illumination furnished by said illuminating means varying randomly with time; timing means for terminating said illumination after a pre-adjustable time interval corresponding to the density of said original, and varying as a function of an energization signal applied to said timing means; photoelectric transducing means positioned to receive Light from said illuminating means, and furnishing an illumination signal corresponding to the light impinging thereon; and energizing means interconnecting said photoelectric transducing means and said timing means and comprising a first operational amplifier having an input connected to said photoelectric transducing means, and a first operational amplifier output, and first capacitor means connected from said first operational amplifier output to said input, said energizing means varying said energization signal in correspondence to the variations in said illumination signal, thereby causing said time interval to vary also as a function of the intensity of the illumination of said illuminating means.
Claim 2
Dependent Claim
165 words
Photographic arrangement for copying an original, comprising, in combination, illuminating means illuminating said original, the intensity of illumination furnished by said illuminating means varying randomly with time; timing means for terminating said illumination after a pre-adjustable time interval corresponding to the density of said original, and varying as a function of an energization signal applied to said timing means; photoelectric transducing means positioned to receive Light from said illuminating means, and furnishing an illumination signal corresponding to the light impinging thereon; and energizing means interconnecting said photoelectric transducing means and said timing means and comprising a first operational amplifier having an input connected to said photoelectric transducing means, and a first operational amplifier output, and first capacitor means connected from said first operational amplifier output to said input, said energizing means varying said energization signal in correspondence to the variations in said illumination signal, thereby causing said time interval to vary also as a function of the intensity of the illumination of said illuminating means.
Claim 3
Dependent Claim
18 words
An arrangement as set forth in claim 1, further comprising measuring means connected to said first operational output.
Claim 4
Dependent Claim
17 words
An arrangement as set forth in claim 2, wherein said measuring means comprise a moving coil instrument.
Claim 5
Dependent Claim
40 words
An arrangement as set forth in claim 2, wherein said measuring instrument has a first terminal connected to said first operational amplifier output, and a second terminal; further comprising a signal source furnishing a balancing signal to said second terminal.
Claim 6
Dependent Claim
38 words
An arrangement as set forth in claim 1, further comprising additional circuit means connected to said first operational amplifier output, said additional circuit means having a transfer characteristic adjustable to correspond to the Schwarzschild coefficient of said original.
Claim 7
Dependent Claim
28 words
An arrangement as set forth in claim 5, wherein the output signal of said additional circuit means is a D.C. voltage, said D.C. voltage energizing said timing means.
Claim 8
Dependent Claim
120 words
An arrangement as set forth in claim 6, wherein said timing means comprise means timing a first and second interval illuminating said original in a first and second color respectively, said means comprising integrator means integrating said D.C. voltage and furnishing an integrated voltage signal; and first and second comparator means respectively comparing said integrated voltage signal to a first and second reference signal and furnishing, respectively, a first and second comparator output signal when said integrated voltage signal has a predetermined relationship to said first and second reference signal respectively; and means terminating the illumination in said first color upon receipt of said first comparator output signal and said second color upon receipt of said second comparator output signal.
References Cited (Backward Citations)
US3482916A
Cited
US3640619A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-04-02 | 1976-10-02 | 1977-04-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-02 | 1980-10-02 | 1981-04-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-02 | 1984-10-02 | 1985-04-03 | $7700.00 | Window Closed / Lapsed |