Method and apparatus for forming gravure cells in a gravure cylinder
First Claim
1. A method of forming gravure cells in a gravure cylinder for accurately reproducing an image, comprising the steps of:
- a. coating the peripheral surface of a gravure cylinder with an insulating coating;
b. revealing a first group of predetermined peripheral portions of the gravure cylinder by selectively removing the insulating coating overlying such portions of the peripheral surface of the gravure cylinder;
c. ablating the first group of revealed portions of the gravure cylinder to a predetermined depth; and
d. repeating the exposing and ablating steps until a predetermined number of different groups of predetermined peripheral portions of the gravure cylinder have been exposed with each previously revealed group of portions having further portions of the gravure cylinder ablated to a greater predetermined depth during each ablating step to provide a gravure cylinder having the desired pattern of cells of the desired depths for accurately reproducing an image.
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0 Petitions
Accused Products
Abstract
A method and associated apparatus for forming gravure cells in a gravure cylinder for accurately reproducing an image, including the steps of coating the peripheral surface of a gravure cylinder with an insulating coating, revealing a first group of predetermined portions of the coated gravure cylinder by selectively removing the insulating coating overlying portions of the peripheral surface of the gravure cylinder, ablating the first group of exposed portions of the gravure cylinder to a predetermined depth, and repeating the revealing and ablating steps until a predetermined number of different groups of predetermined portions of the gravure cylinder have been revealed with each previously revealed group having further portions of the gravure cylinder ablated to a greater predetermined depth during each ablating step to provide a gravure cylinder having the desired pattern of gravure cells of the desired depths for accurately reproducing an image.
111 Citations
41 Claims
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1. A method of forming gravure cells in a gravure cylinder for accurately reproducing an image, comprising the steps of:
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a. coating the peripheral surface of a gravure cylinder with an insulating coating; b. revealing a first group of predetermined peripheral portions of the gravure cylinder by selectively removing the insulating coating overlying such portions of the peripheral surface of the gravure cylinder; c. ablating the first group of revealed portions of the gravure cylinder to a predetermined depth; and d. repeating the exposing and ablating steps until a predetermined number of different groups of predetermined peripheral portions of the gravure cylinder have been exposed with each previously revealed group of portions having further portions of the gravure cylinder ablated to a greater predetermined depth during each ablating step to provide a gravure cylinder having the desired pattern of cells of the desired depths for accurately reproducing an image. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A method of forming gravure cells in a gravure cylinder for accurately reproducing an image, comprising the steps of:
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coating a gravure cylinder with an electrically insulating coating; rotating the gravure cylinder; conducting a first scan of the peripheral surface of the gravure cylinder with at least one laser beam to cover a discrete segment of the length of the gravure cylinder; modulating the laser beam during the first scan to selectively reveal predetermined portions of gravure cylinder designated as a first group by removing the insulating coating therefrom; de-energizing the laser beam after the first scan is completed; ablating those portions of the surface of the gravure cylinder revealed by the laser beam during the period when the laser beam is de-energized to remove portions of the gravure cylinder from the revealed portions to a predetermined depth; and conducting subsequent laser beam scans for revealing other groups of predetermined portions of the insulating coating, each subsequent laser beam scan followed by the step of ablating until a predetermined number of different groups of predetermined portions of the peripheral surface of the gravure cylinder have been revealed with each previously revealed group of predetermined portions having further portions of the gravure cylinder ablated to a greater predetermined depth during each ablating step to provide a gravure cylinder having the desired pattern of gravure cells of the desired depths for accurately reproducing an image. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18)
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19. Apparatus for forming gravure cells in a gravure cylinder for accurately reproducing an image, comprising:
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a gravure cylinder having an insulating coating thereon; removal means positioned adjacent to the gravure cylinder for selectively removing predetermined portiohs of the insulating coating to reveal a first group of peripheral portions of the gravure cylinder; ablating means providing an ablating period for ablating a predetermined depth of the gravure cylinder from the fist group of peripheral portions; said removal means further selectively removing other predetermined portions of the insulating coating to reveal subsequent groups of peripheral portions; and said ablating means providing subsequent ablating periods for further ablating all previously revealed groups of peripheral portions to provide a gravure cylinder having the desired pattern of gravure cells with the desired cell depths for accurately reproducing an image. - View Dependent Claims (20, 21, 22, 23, 24, 25, 26, 27, 28, 29)
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30. Apparatus for forming gravure cells in a gravure cylinder for accurately reproducing a desired image, comprising:
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a gravure cylinder coated with an electrical insulator; at least one laser arranged adjacent said gravure cylinder for scanning a discrete segment of the length of said gravure cylinder; an electrolytic bath arranged proximate to said gravure cylinder; means for rotating said gravure cylinder through said electrolytic bath; modulation means for modulating said laser during a first scan to reveal a first group of predetermined portions of the peripheral surface of the gravure cylinder which underlie the electrical insulator; means for subjecting the portions of said gravure cylinder exposed by said laser to electrolysis to engrave the first group of predetermined portions to a predetermined depth; said modulation means activating said laser for revealing subsequent groups of predetermined portions of the peripheral surface of said coated gravure cylinder; and said electrolysis means providing electrolysis of all previously revealed groups of predetermined portions subsequent to each laser scan so that upon completion of the final laser scan and electrolysis a gravure cylinder is provided having the desired pattern of gravure cells with the desired depths for accurately reproducing an image. - View Dependent Claims (31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41)
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Specification