When was the process for a halftone printing press patented?
Answers
Answer:
Halftone is the reprographic technique that simulates continuous-tone imagery through the use of dots, varying either in size or in spacing, thus generating a gradient-like effect."Halftone" can also be used to refer specifically to the image that is produced by this process.
Where continuous-tone imagery contains an infinite range of colors or greys, the halftone process reduces visual reproductions to an image that is printed with only one color of ink, in dots of differing size (pulse-width modulation) or spacing (frequency modulation) or both. This reproduction relies on a basic optical illusion: when the halftone dots are small, the human eye interprets the patterned areas as if they were smooth tones. At a microscopic level, developed black-and-white photographic film also consists of only two colors, and not an infinite range of continuous tones. For details, see Film grain
Answer:
In an 1852 patent he suggested using "photographic screens or veils" in connection with a photographic intaglio process. Several different kinds of screens were proposed during the following decades. One of the first attempts was by William Leggo with his leggotype while working for the Canadian Illustrated News.