Printing screen and method of making same
OwnerFrank A. Sportelliinventor
Life of this patent
Estimating the term…
Abstract
A printing plate is made in accordance with a particular method and is used in a printing process wherein it is effective to produce a substantially continuous tone printing effect. A negative screen having an overall pattern defined by rows of closely spaced substantially square-shaped areas is exposed a plurality of times on an image carrier. An image screen pattern is developed on the image carrier wherein each of the plurality of exposures of the overall pattern on the negative screen is effected at a different angle with respect to each other. A unique printing screen pattern is obtained which is then used for printing a reproduced image.
Claims17
A method of making a photoprinting image element, said method comprising:
- (a) providing a negative screen having two sets of parallel equispaced lines located thereon, each said set being perpendicular to each other,
- (b) providing a photographic film to be exposed,
- (c) exposing the negative screen onto the photographic film in at least three separate exposures,
- (d) said negative screen being disposed at a predetermined angle in each said separate exposure,
- (e) each said predetermined angle being at a different angle with respect to each other, and
- (f) developing the exposed photographic film to produce a photoprinting image element having a regular screen pattern as shown in FIG. 2.
In the method of making a printing screen pattern, the process comprising:
- (a) providing a negative screen having an overall pattern defined by rows of closely spaced substantially square-shaped areas,
- (b) providing a light-sensitive image carrier effective to receive at least three exposures of said overall pattern on the negative screen, exposing said carrier to said three exposures, and
- (c) developing an image screen pattern as shown in FIG. 2 on said image carrier wherein each of said three exposures of said overall pattern on said negative screen is effected at a different angle on said image carrier.
Dependencies are inferred from the claim text.