Guadrascan styli for use in staggered recording head

Abstract

A recording head for use in an electrostatic printer comprises four staggered rows of styli. Signals for driving each row of styli are transmitted through a buffer wherein the signals for the first row of styli are transmitted without delay to the styli, the signals for the second row of styli are transmitted with an appropriate delay of a first selected time, the signals for the third row of styli are transmitted with an appropriate delay of a second selected time and the signals for the fourth row of styli are transmitted with an appropriate delay of a third selected time. The delay means comprises a random access memory driven by address counters controlled by a control sequencer to function as a delay. The four staggered rows of styli are formed by a novel method wherein the styli in the second row are formed between the styli in the first row and the stylis in the third and fourth rows are formed by making use of the grooves formed between the styli in the first and second rows. By forming the rows of styli on a cylindrical drum, two recording heads are obtained from each fabrication run wherein the recording head in one set of styli is the mirror image of the recording head in the other set of styli. Should an error occur in the manufacture of the styli by placing the third row of styli in the grooves where the fourth row of styli normally belongs, the resulting recording heads are identical to those obtained with the proper placement of the third and fourth rows with the exception that the position on the drum of each type of recording head is reversed.