Method and apparatus for the manufacture of printing plates
AssigneeHoechst Aktiengesellschaft
InventorFerdinand Friese
Life of this patent
Estimating the term…
Abstract
A method and apparatus for the manufacture of printing masters by electrophotographic means in which the unexposed printing masters are placed in the apparatus in a printing master holder and undergo electrostatic charging, image exposure, development, drying and discharging from the apparatus mechanically. The apparatus provides a charging device, a lighting device for indirect illumination of an original, an imaging device for projecting the image of the original in a preselected scale onto the printing master, and transportation, development, and drying means.
Claims24
An apparatus for the manufacture of printing masters by electrophotographic means comprising:
- a frame supporting an unexposed printing master holder and carriage means for removal of unexposed printing master from said holder by reduced pressure of a vacuum plate;
- an exposure platform communicating with said frame to receive said unexposed printing master from said carriage means and securely retain said printing master during charging and exposure thereof;
- charging means communicating with said frame for electrostatic charging of said printing master retained to said exposure platform;
- means communicating with said frame for holding an image containing original for illumination and projection onto said printing master;
- means communicating with said frame for illumination of said original by radiation sources capable of only indirect illumination of said original;
- means communicating with said illumination means for projection of image of said original onto said charged printing master;
- and
- means communicating with said frame for transportation, developing and drying of said printing master after exposure of said printing master to said projected image.
An electrophotographic method for the manufacture of printing masters comprising:
- arranging an image containing original in a holder, mechanically transferring an unexposed printing master by reduced pressure from a printing master holder to an exposure platform, electrostatically charging said unexposed printing master, exposing said printing master to said image of said original projected through a movable optical system by way of an indirect illumination of said original, mechanically transferring said exposed printing master to a developing device, developing and fixing the latent electrostatic image on said printing master, mechanically transferring said developed printing master to a drying device, and drying said developed printing master.
Dependencies are inferred from the claim text.