Method and means for the preparation of printing forms, especially of intaglio printing surfaces

Claim 1

APPARATUS FOR PRODUCING AN ENGRAVED PRINTING FORM COMPRISING IN COMBINATION: AN ELECTRON BEAM GENERATOR FOR PROJECTING ON A GIVEN PLANE A SHARPLY FOCUSED BEAM OF ELECTRONS, FIRST MOUNTING MEANS FOR SUPPORTING AND POSITIONING AN ELECTRON BEAM ENGRAVABLE MEDIUM IN SAID PLANE IN THE PATH OF SAID BEAM, A HOUSING ENCLOSING BOTH SAID GENERATOR AND SAID FIRST MOUNTING MEANS, MEANS COUPLED THERETO FOR PRODUCING A VACUUM WITHIN SAID HOUSING ALONG THE ENTIRE PATH OF SAID BEAM MEANS FOR CAUSING SAID ELECTRON BEAM TO TRAVERSE THE SURFACE OF SAID ENGRAVABLE MEDIUM IN ACCORDANCE WITH A PATTERN WHICH IS IDENTICAL AND IN ABSOLUTE SYNCHRONISM WITH A PREDETERMINED SCANNING PATTERN OF AN ORIGINAL, MEANS FOR COUPLING TO SAID BEAM GENERATOR FOR CONTROLLING THE INTENSITY OF THE BEAM A SIGNAL REPRESENTATIVE OF THE BRIGHTNESS VALUES OF SAID ORIGINAL ALONG SAID SCANNING PATTERN, AND MEANS DIRECTLY SYNCHRONIZED WITH THE TRANSVERSE OF THE BEAM OVER THE SURFACE OF THE ENGRAVING MEDIUM FOR PERIODICALLY SUPPRESSING THE ENGRAVING ACTION OF SAID BEAM TO PROVIDE THE CHARACTERISTIC DOT PATTERN OF A PRINTING FORM.