Halftone printing system
AssigneeInnovative Photograhic Enterprises, Inc.
InventorRobert W. Stevie
Life of this patent
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Abstract
In a halftone printing system, halftone positive prints are made directly from gray scale photographic negatives by an enlarger apparatus which shines a beam of light through the negative and focuses an image of the negative on a sheet of high contrast photographic printing paper through a halftone screen. A secondary light source is provided to irradiate the printing paper to provide satisfactory halftone representation of the gray scale. The positive halftone prints are assembled with cold type from which a negative is made. From the negative, a printing plate is then made.
Claims5
A method of making a printing plate comprising focusing light into a gray scale image onto photographic printing paper through a halftone screen and irradiating said paper through said screen with light in addition to the light focused into said gray scale image, said printing paper being selected to have a sufficiently high contrast rating to produce dots which are uniformly black with no shades of gray over the area of each dot in the resulting halftone image produced on said printing paper, assembling said halftone print with cold type to make up a page, making a negative of the assembly of said cold type and said halftone print, and making a printing plate from said negative.
Dependencies are inferred from the claim text.