Patent EP0409608A2 successfully refreshed from Google Patents.
EP0409608A2
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EP
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Method for offset and similar printing systems
Assignee: HOFFMAN, ARNOLD
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Filing: 1990-07-19
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Granted: —
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Expires: 2010-07-19
Abstract
Abstract The invention provides a device for offset and similar printing from a continuous tone original to produce a halftone image on a photosensitive layer comprising means for screening the information via a first array of parallely extending lines of effective minimum optical density and a second array of parallely extending lines of effective maximum optical density, the arrays being interposed to form a composite array of substantially parallel, spaced-apart, alternating lines of effective maximum and minimum optical density, the lines delimiting therebetween zones of effective graduated optical density, the gradient inside each zone progressively varying from low optical density adjacent lines of the first array to high optical density adjacent lines of the second array, the spacing of lines of the first array being between about 100 and 400 lines per inch and wherein the resulting thickness of each reproduced line on a resulting developed photosensitive layer, generated by screening the information via the array, continuously varies as a function of the density of each information point of the original.
Inventors
- 👤 Yoel Netz
- 👤 Arnold Hoffman
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 18:48
CPC Classifications
G; G03; G03F; G03F5/00; G03F5/22; G03F5/02; G03F5/08; H; H04; H04N; H04N1/00; H04N1/40; H04N1/405; H04N1/4055; H04N1/4058
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
167 words
A device for offset and similar printing from a continuous tone original to produce a halftone image on a photosensitive layer comprising means for screening said information via a first array of parallely extending lines of effective minimum optical density and a second array of parallely extending lines of effective maximum optical density, said arrays being interposed to form a composite array of substantially parallel, spaced-apart, alternating lines of effective maximum and minimum optical density, said lines delimiting therebetween zones of effective graduated optical density, the gradient inside each zone progressively varying from low optical density adjacent lines of said first array to high optical density adjacent lines of said second array, the spacing of lines of said first array being between about 100 and 400 lines per inch and wherein the resulting thickness of each reproduced line on a resulting developed photosensitive layer, generated by screening said information via said array, continuously varies as a function of the density of each information point of the original.
Claim 2
Independent Claim
167 words
A device for offset and similar printing from a continuous tone original to produce a halftone image on a photosensitive layer comprising means for screening said information via a first array of parallely extending lines of effective minimum optical density and a second array of parallely extending lines of effective maximum optical density, said arrays being interposed to form a composite array of substantially parallel, spaced-apart, alternating lines of effective maximum and minimum optical density, said lines delimiting therebetween zones of effective graduated optical density, the gradient inside each zone progressively varying from low optical density adjacent lines of said first array to high optical density adjacent lines of said second array, the spacing of lines of said first array being between about 100 and 400 lines per inch and wherein the resulting thickness of each reproduced line on a resulting developed photosensitive layer, generated by screening said information via said array, continuously varies as a function of the density of each information point of the original.
Claim 3
Dependent Claim
167 words
A photomechanical screen according to claim 1 for offset and similar printing by screening information from a continuous tone original to produce a halftone image on a photosensitive layer, said screen comprising a first array of parallely extending lines of minimum optical density and a second array of parallely extending lines of maximum optical density, said arrays being interposed to form a composite array of substantially parallel spaced-apart, alternating lines of maximum and minimum optical density, said lines delimiting therebetween zones of graduated optical density, the gradient inside each zone progressively varying from low optical density adjacent lines of said first array to high optical density adjacent lines of said second array, the spacing of lines of said first array being between about 100 and 400 lines per inch and wherein the resulting thickness of each reproduced line on a resulting developed photosensitive layer, generated by screening said information via said array, continuously varies as a function of the density of each information point of the original.
Claim 4
Dependent Claim
24 words
A device according to claim 1 wherein the spacing of lines of said first array is between about 200 and 300 lines per inch.
Claim 5
Dependent Claim
63 words
A method for generating a halftone image from a continuous tone original comprising exposing a commercial lith or line film to a continuous tone original via a device according to claim 1 wherein the resulting thickness of each resulting line generated on said developed lith or line film continuously varies as a function of the density of each information point of the original.
Claim 6
Dependent Claim
49 words
A method according to claim 4, comprising electronically outputting the information of the original onto an unexposed scanner type film, in an electronic output simulating a screen format, the pattern of this screen being lines spaced 100-400 lines/inch without this film being in contact with a standard photomechanical screen.
Claim 7
Dependent Claim
44 words
A method according to claim 5, comprising electronically separating and outputting the information of a color original, onto four separate unexposed scanner type films, without said films being in contact with a standard photomechanical screen, each separation generated at different angles to attenuate Moire.
Claim 8
Dependent Claim
22 words
A method according to claim 6 wherein said angles are 45 o , 90 o , 105 o and 165 o respectively.
Claim 9
Dependent Claim
16 words
A method according to claim 6 wherein the angles between the separations are 30 o .
Claim 10
Independent Claim
208 words
A method for generating a halftone image from a continuous tone original comprising outputting the information of the original onto an unexposed scanner-type film, in an electronic output simulating a screen format, the pattern of this screen being a first array of parallely extending lines of effective minimum optical density and a second array of parallely extending lines of effective maximum optical density, said arrays being interposed to form a composite array of substantially parallel, spaced-apart, alternating lines of effective maximum and minimum optical density, said lines delimiting therebetween zones of effective graduated optical density, the gradient inside each zone progressively varying from low optical density adjacent lines of said first array to high optical density adjacent lines of said second array, the spacing of lines of said first array being between about 400-600 lines per inch and developing in a lith developer containing a hydroquinone developing agent in combination with carbonate, bicarbonate and halide salt together with sodium formaldehyde sulfoxylate and formaldehyde wherein a resulting thickness of each resulting line generated on said scanner type film continuously varies as a function of each information point of the original, but does not decrease in the Dmin region beyond 5 microns width even when the generated line becomes segmented.
Claim 11
Independent Claim
208 words
A method for generating a halftone image from a continuous tone original comprising outputting the information of the original onto an unexposed scanner-type film, in an electronic output simulating a screen format, the pattern of this screen being a first array of parallely extending lines of effective minimum optical density and a second array of parallely extending lines of effective maximum optical density, said arrays being interposed to form a composite array of substantially parallel, spaced-apart, alternating lines of effective maximum and minimum optical density, said lines delimiting therebetween zones of effective graduated optical density, the gradient inside each zone progressively varying from low optical density adjacent lines of said first array to high optical density adjacent lines of said second array, the spacing of lines of said first array being between about 400-600 lines per inch and developing in a lith developer containing a hydroquinone developing agent in combination with carbonate, bicarbonate and halide salt together with sodium formaldehyde sulfoxylate and formaldehyde wherein a resulting thickness of each resulting line generated on said scanner type film continuously varies as a function of each information point of the original, but does not decrease in the Dmin region beyond 5 microns width even when the generated line becomes segmented.
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