Abstract: This invention relates to a method and apparatus for the electronic screening of a graphic image to be reproduced by printing. The density of the graphic image is determined repetitively during the digital generation of each dot which will form a part of the half-tone image when produced, and the dot is modified according to changes in the density. Thus the structure of any half-tone dot may be modified during its construction.
Type:
Grant
Filed:
August 13, 1975
Date of Patent:
August 2, 1977
Assignee:
International Publishing Corporation Ltd.
Inventors:
Robert Charles Everett, Paul Anthony Beaufort Radcliffe, Alfred Henry Robinson, Janusz Andrew Veltze
Abstract: This invention relates to apparatus for the reproduction of graphic material which is capable of operating a photo-composing device for reproducing the graphic material as an image on a photosensitive surface. The apparatus scans the graphic material with a light spot associated with a photosensitive device to produce an electrical output signal modulated according to the graphic information and which is employed to reproduce the graphic information on the photo-composing device. Control means are provided for positioning the scanning light spot at the start of each scan according to predetermined co-ordinates, whereby any scan can be commenced at any desired point on any item of graphic material within the field of scan of the light spot.
Type:
Grant
Filed:
December 26, 1973
Date of Patent:
July 5, 1977
Assignee:
International Publishing Corporation Ltd.
Inventors:
David Gregory Owen, John Vernon Ashworth, Paul Anthony Beaufort Radcliffe