Abstract: An electric discharge printing device has the stylus formed as a conductive lamina with the stylus tip formed as the corner at which two edges of the lamina of the stylus intersect. The lamina is electrically energized to exert the appropriate electric discharge printing action on a copy sheet, such as a duplicating stencil to be cut electrically. The plane of the lamina is perpendicular to the copy sheet but parallel to the direction of relative motion between the stylus tip and the sheet, in use of the device.

Abstract: In a document copier in which forward and reverse travel of a scanning member, preferably a document-carrying carriage moving past a stationary scanning source, is driven in a forward direction by a first drive chain, and entrained for movement in a reverse direction by a second, more rapidly circulating drive chain. The second drive chain is effective also to drive the image-developer unit and the sheet feed system of the copier. In the preferred embodiment, the first drive member is synchronized to circulate at the same speed as the peripheral speed of rotation of the photoconductor drum.