Electrographic marking with modified addressing to eliminate striations

Abstract

In a device for producing an electrostatic image along a scan line of a recording medium by means of a recording device including an array of stylus electrodes arranged in a series of groups cooperable with a series of complementary electrodes, each of the stylus electrode groups cooperates with a portion of two adjacent complementary electrodes whereby writing is accomplished by imposing a charge pattern upon the recording medium in the region of a stylus electronic group when both the stylus electrode group and its cooperating pair of complementary electrodes are actuated contemporaneously. As each complementary electrode is actuated it induces a non-uniform residual potential distribution in the recording medium of a portion of the region of the next adjacent stylus electrode group. The electrostatic writing method comprises first perturbing a region of the recording medium by imposing a first non-uniform residual potential distribution on one portion thereof coextensive with the overlapping portion of a complementary electrode, then perturbing another portion of the same region by imposing a second non-uniform residual potential distribution thereon coextensive with the overlapping portion of another adjacent complementary electrode, wherein the first and second non-uniform residual potential distributions tend to cancel one another, and then writing a charge pattern upon the entire region.