Electronic Engraver

an electromechanical apparatus employed for the automatic preparation of cuts used in monochromatic and color relief printing.

Electronic engravers were developed by J. H. Howey of the USA in 1932 and by N. P. Tolmachev of the USSR in 1934. The Howey principle of operation of an electronic engraver is based on a line-by-line sweep, or scan, of an illustration and the conversion of the light reflected from the illustration into electric energy. The electric energy is then used to control an engraving unit, whose stylus creates depressions, or cells, in metal or plastic plate stock. The depth and area of the cells are inversely proportional to the color saturation or tone of the original, and there may be from 400 to 3,600 or more cells per square centimeter. An electronic engraver can engrave at a rate of 12 m/min.

Figure 1. Simplified diagram of an electronic engraver: (1) and (2) cylinders to which the original and the plate stock are attached; (3) scanning unit, which includes a point-source light and a photocell; (4) power and voltage operational amplifier; (5) engraving unit

Unlike zincographic processes, the preparation of a plate with an electronic engraver is completely automated. It requires less working space and makes possible lower production costs and improved working conditions. Electronic engravers are widely used in printing houses and printing combines.

Since the 1960’s, electronic engravers have also been manufactured for the preparation of intaglio plates on copper-surfaced cylinders that reproduce not only illustrations but also text.