US3864036A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for controlling exposure
Assignee: Agfa Gevaert AG
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Filing: 1974-03-13
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Granted: 1975-02-04
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Expires: 1994-03-13
Abstract
Abstract Apparatus for controlling exposure of variable contrast photosensitive material which is exposed to light passing through an original in two extreme colors and whose gradation is different for each extreme color comprising an electronic timer having adjusting devices for selecting the total exposure time to light in the two colors as determined on the basis of the contrast grade of the photosensitive material; an operating arrangement for selecting the ratio of exposures to light in the two colors within the total exposure time; first exposure selecting devices having calibrating values determined by the desired contrast of the exposed photosensitive material; second exposure selecting devices having calibrating values determined on the basis of the minimum and maximum densities of the original; and connecting circuits connecting the operating arrangement and the first and second exposure selection devices and being operative to automatically select the two color exposure ratio on the basis of the calibrating values.
Inventors
- 👤 Jacques Vanheerentals
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 06:12
CPC Classifications
G; G03; G03C; G03C5/00; G03C5/02; G03B; G03B27/00; G03B27/72; G03B27/727
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
149 words
In an apparatus for controlling the exposure of variablecontrast photo-sensitive material which is exposed to light passing through an original in two colors, and whose gradation is different for each of said colors, a combination comprising electronic timer means having adjusting means for selecting the total exposure time to light in said colors, determined on the basis of the contrast grade of said photo-sensitive material; operating means for selecting the ratio of exposures to light in said colors within said total exposure time; first exposure selecting means having calibrating values determined by the desired contrast of the photo-sensitive material; second exposure selecting means having calibrating values determined on the basis of the minimum and maximum densities of said original, and connecting means connecting said operating means and said first and second exposure selection means and being operative to automatically select said ratio on the basis of said calibrating values.
Claim 2
Dependent Claim
149 words
In an apparatus for controlling the exposure of variablecontrast photo-sensitive material which is exposed to light passing through an original in two colors, and whose gradation is different for each of said colors, a combination comprising electronic timer means having adjusting means for selecting the total exposure time to light in said colors, determined on the basis of the contrast grade of said photo-sensitive material; operating means for selecting the ratio of exposures to light in said colors within said total exposure time; first exposure selecting means having calibrating values determined by the desired contrast of the photo-sensitive material; second exposure selecting means having calibrating values determined on the basis of the minimum and maximum densities of said original, and connecting means connecting said operating means and said first and second exposure selection means and being operative to automatically select said ratio on the basis of said calibrating values.
Claim 3
Dependent Claim
16 words
A combination as defined in claim 1, wherein said first exposure selecting means comprise a potentiometer.
Claim 4
Dependent Claim
33 words
A combination as defined in claim 1, wherein said sevond exposure selecting means comprise a movable scale marked with density calibrating values, and first and second photoelectric cells slidably mounted on said scale.
Claim 5
Dependent Claim
28 words
A combination as defined in claim 3, wherein said photoelectric cells are positioned at calibrating values on said scale corresponding to minimum and maximum densities of said original.
Claim 6
Dependent Claim
18 words
A combination as defined in claim 1, wherein said adjusting means of said timer means comprises a potentiometer.
Claim 7
Dependent Claim
24 words
A combination as defined in claim 4, wherein said operating means compriseS a calibrating film representing different lightness and hue of said variable-contrast material.
Claim 8
Dependent Claim
38 words
A combination as defined in claim 6, further comprising a light source, and wherein said calibrating film is interposed between said light source and said photoelectric cells so that said cells detect the light transmitted through said film.
Claim 9
Dependent Claim
32 words
A combination as defined in claim 7, wherein said film is mounted circumferentially on a rotatable drum, and said scale is situated at the surface of said drum parallel to its axis.
Claim 10
Dependent Claim
26 words
A combination as defined in claim 8, wherein said scale is moveable by a first motor in a direction parallel to the axis of the drum.
Claim 11
Dependent Claim
40 words
A combination as defined in claim 7, further comprising a first potentiometer having a wiper arm; and wherein said scale is connected to the wiper arm of said first potentiometer so as to register the lateral displacement of said scale.
Claim 12
Dependent Claim
43 words
A combination as defined in claim 10, further comprising a second potentiometer having a wiper arm; and wherein a shaft of said drum is connected to said wiper arm of said second potentiometer so as to register the angular displacement of said drum.
Claim 13
Dependent Claim
23 words
A combination as defined in claim 6, wherein said calibrating film comprises the developed image of a gray wedge with different color ratios.
Claim 14
Dependent Claim
15 words
A combination as defined in claim 12, wherein said colors are sequentially exposed and super-imposed.
Claim 15
Dependent Claim
35 words
A combination as defined in claim 9, wherein said first motor is connected to an output of first comparing means, and a first input of said first comparing means is connected to said first photocell.
Claim 16
Dependent Claim
16 words
A combination as defined in claim 8, wherein said drum is rotatable by a second motor.
Claim 17
Dependent Claim
35 words
A combination as defined in claim 15, wherein said second motor is connected to an output of second comparing means, and a first input of said second comparing means is connected to said second photocell.
Claim 18
Dependent Claim
33 words
A combination as defined in claim 14, wherein said first exposure selecting means comprises first and second potentiometers, and said first potentiometer is connected with said second input of said first comparing means.
Claim 19
Dependent Claim
33 words
A combination as defined in claim 16, wherein said first exposure selecting means comprises first and second potentiometers, and said second potentiometer is connected with said second input of said second comparing means.
Claim 20
Dependent Claim
51 words
A combination as defined in claim 1, wherein said connecting means comprise first and second comparing means which compare said calibrating values of said second exposure selecting means with said calibrating values of said first exposure selecting means to activate switching means when said calibrating values satisfy a predetermined functional relationship.
Claim 21
Dependent Claim
15 words
A combination as defined in claim 19, wherein said switching means activates said timer means.
Claim 22
Dependent Claim
32 words
A combination as defined in claim 19, wherein said second exposure selecting means comprises a photoelectric cell, and said calibrating values of said second exposure selecting means are determined by said cell.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-02-03 | 1978-08-05 | 1979-02-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-02-03 | 1982-08-05 | 1983-02-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-02-03 | 1986-08-05 | 1987-02-04 | $7700.00 | Window Closed / Lapsed |