US3875587A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Colour scanners for image reproduction
Assignee: Crosfield Electronics Ltd
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Filing: 1973-05-18
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Granted: 1975-04-01
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Expires: 1993-05-18
Abstract
Abstract In a method and apparatus of image reproduction in which a light-sensitive surface is scanned by a light beam modulated by a reproducing head in accordance with a signal representing the densities of successive image elements to be reproduced, a component of the scanning motion is obtained by mounting the light-sensitive surface on the non-rotating surface of a cylinder and rotating a portion of the reproducing head within the cylinder so as to define a circular track on the output surface during one revolution of the rotatable portion of the reproducing head. A rotatable prism having a plurality of internal reflecting surfaces, such as a pentaprism, may reflect the light beam and may move axially within the cylinder to provide the other component of scanning motion. The pentaprism is advantageous during the presence of rotational vibration. Additionally, a plurality of light-sensitive surfaces may be placed sequentially on the surface of the cylinder to form respective color separations.
Inventors
- 👤 Peter C Pugsley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 11:37
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/04; H04N1/06; H04N1/0607; H04N1/0621; H04N1/0642; H04N1/047; H04N1/053; H04N1/0657; H04N1/0671; H04N1/0678; H04N1/203; H04N1/2036; H04N1/207; H04N1/46; H04N1/50; H04N1/506; H04N1/508; H04N2201/00; H04N2201/024; H04N2201/02406; H04N2201/02416; H04N2201/02439; H04N2201/02443; H04N2201/04; H04N2201/0402; H04N2201/0404; H04N2201/047; H04N2201/04701; H04N2201/0471; H04N2201/04715; H04N2201/04724; H04N2201/04732; H04N2201/04734; H04N2201/04753; H04N2201/04755; H04N2201/04758; H04N2201/04767; H04N2201/04768; H04N2201/04781; H04N2201/04786; H04N2201/04789; H04N2201/04791; H04N2201/04794; H04N2201/04798
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
193 words
A method of reproducing an image on a light-sensitive surface by scanning the surface with a light beam modulated in accordance with an electric signal obtained by scanning an original to be reproduced and representing the density or a color-component density of successively scanned elements of the original, the method comprising the steps of: mounting the light-sensitive recording surface on the cylindrical surface of a non-rotating cylinder; mounting a rotatable prism having a plurality of internal reflecting surfaces, with a number of said surfaces sequentially reflecting an incident light beam, within and on the axis of said cylinder and rotating said reflector about the said axis; directing a light beam along the axis of said cylinder so that it is internally reflected by said number of surfaces internally to said cylindrical surface to define a circular track thereon; and progressively displacing said circular track along said cylindrical surface to define a scanning raster on the said light-sensitive surface mounted on said cylindrical surface by relative movement of said cylinder and light-sensitive surface on the one hand and said prism on the other hand in a direction parallel to the axis of said cylinder.
Claim 2
Independent Claim
193 words
A method of reproducing an image on a light-sensitive surface by scanning the surface with a light beam modulated in accordance with an electric signal obtained by scanning an original to be reproduced and representing the density or a color-component density of successively scanned elements of the original, the method comprising the steps of: mounting the light-sensitive recording surface on the cylindrical surface of a non-rotating cylinder; mounting a rotatable prism having a plurality of internal reflecting surfaces, with a number of said surfaces sequentially reflecting an incident light beam, within and on the axis of said cylinder and rotating said reflector about the said axis; directing a light beam along the axis of said cylinder so that it is internally reflected by said number of surfaces internally to said cylindrical surface to define a circular track thereon; and progressively displacing said circular track along said cylindrical surface to define a scanning raster on the said light-sensitive surface mounted on said cylindrical surface by relative movement of said cylinder and light-sensitive surface on the one hand and said prism on the other hand in a direction parallel to the axis of said cylinder.
Claim 3
Dependent Claim
32 words
A method in accordance with claim 1, comprising moving said prism along the axis of said cylinder to obtain said relative movement in a direction parallel to the axis of said cylinder.
Claim 4
Dependent Claim
33 words
A method in accordance with claim 1, in which said cylinder is transparent, the method comprising mounting said light-sensitive sheet on the external surface of said transparent cylinder with its sensitive side innermost.
Claim 5
Dependent Claim
90 words
A method in accordance with claim 1, in which said light-sensitive recording surface and a mask are mounted on a common cylindrical track of said cylindrical surface, the said beam serving both to expose said light-sensitive surface and to illuminate said mask, and during illumination of said mask scanning said mask with a photo-electric device and deriving an electric signal therefrom representing the density of successively scanned elements of said mask to control the substitution of replacement signals for parts of the said electric signal obtained by scanning the original.
Claim 6
Dependent Claim
190 words
Image-reproduction apparatus comprising: a cylinder; a medium having a light-sensitive recording surface on which an image is to be reproduced received on the surface of said cylinder; a reproducing head for exposing the said light-sensitive surface, element by element, to form an image thereon, said reproducing head including means for directing a beam of light along the axis of said cylinder, a rotatable prism having a plurality of internal reflecting surfaces, with a number of said surfaces sequentially reflecting an incident light beam, mounted within said cylinder and on the axis thereof, so as to reflect the said beam to the said cylindrical suRface, and means for modulating the beam intensity; driving means for rotating said prism about the axis of the cylinder to cause the said beam to move around a circular track of the cylindrical surface; and means for effecting relative movement between said prism and light-sensitive surface on said cylindrical surface in a direction parallel to the axis of said cylinder to cause progressive displacement of the circular track along the cylindrical surface and thus define a scanning raster on said light-sensitive surface on the cylindrical surface.
Claim 7
Dependent Claim
190 words
Image-reproduction apparatus comprising: a cylinder; a medium having a light-sensitive recording surface on which an image is to be reproduced received on the surface of said cylinder; a reproducing head for exposing the said light-sensitive surface, element by element, to form an image thereon, said reproducing head including means for directing a beam of light along the axis of said cylinder, a rotatable prism having a plurality of internal reflecting surfaces, with a number of said surfaces sequentially reflecting an incident light beam, mounted within said cylinder and on the axis thereof, so as to reflect the said beam to the said cylindrical suRface, and means for modulating the beam intensity; driving means for rotating said prism about the axis of the cylinder to cause the said beam to move around a circular track of the cylindrical surface; and means for effecting relative movement between said prism and light-sensitive surface on said cylindrical surface in a direction parallel to the axis of said cylinder to cause progressive displacement of the circular track along the cylindrical surface and thus define a scanning raster on said light-sensitive surface on the cylindrical surface.
Claim 8
Dependent Claim
38 words
Apparatus in accordance with claim 5, in which said cylinder is of transparent material, whereby the light-sensitive surface can be placed around the external surface of the cylinder with its sensitive side innermost and exposed through said cylinder.
Claim 9
Dependent Claim
13 words
Apparatus in accordance with claim 5, in which said prism is a pentaprism.
Claim 10
Dependent Claim
90 words
Apparatus in accordance with claim 5, including an input cylinder and an analyzing head for deriving electric signals representing the density, or color-component density, of successively scanned elements of an original mounted on the said input cylinder, an electric motor coupled to said input cylinder to drive the latter in rotation relative to said analyzing head, and a synchro transmission unit for transmitting drive from said motor to said prism, said synchro transmission unit including a differential synchro adjustable to move the position of the image on said light-sensitive surface.
Claim 11
Dependent Claim
128 words
Apparatus in accordance with claim 5, for use when two or more light-sensitive surfaces, each destined to form a respective color separation of an original, are mounted on a single cylindrical track of said cylinder, the apparatus including: switching means having a number of inputs and an output connected to said reproducing head; means for applying to the inputs of said switching means respective electric signals representing density variations of each color component required for the respective color separations; and means synchronized with the rotation of said prism for controlling the operation of said switching means so that there are applied to the reproducing head, in the course of a revolution of said prism, electric signals which successively represent a line of each of the said color separations.
Claim 12
Dependent Claim
132 words
Apparatus in accordance with claim 5, for use when a mask is to be analyzed, to provide an electric signal for controlling the substitution of replacement signals for image-representing signals used to control the exposure of the light-sensitive surface on a single cylindrical track of said cylinder, said reproducing head including a beam-intensity modulating means, the apparatus further comprising: switching means coupled to said modulating means and controlled in accordance with the rotation of said prism to render said modulating means operative to modulate the beam intensity during scanning of said light-sensitive surface and to maintain the intensity of the beam at a constant level during scanning of the mask; and a photo-electric device receiving light from the mask and providing signals representing the density of successively scanned elements of the mask.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-03-31 | 1978-09-30 | 1979-04-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-31 | 1982-09-30 | 1983-04-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-31 | 1986-09-30 | 1987-04-01 | $7700.00 | Window Closed / Lapsed |