Electronic register control for multicolor printing

The proper register for multicolor printing, that is, the printing of as many as five colors on top of one another to the required accuracy of a few thousandths of an inch, has been successfully solved by the use of phototubes and associated electronic equipment. In the system described, the electronic portion extends all the way from the phototubes to the thyratrons which supply the required current to energize the correcting motor armature in the proper direction and at the speed for correct register. A typical installation is shown in Figure 1.