SELFOC ADDITIVE SCREENER
Original Publication Date: 1986-Dec-31
Included in the Prior Art Database: 2004-Apr-04
Xerox Disclosure Journal
A charged photoconductive member may have a screened pattern formed thereon by illuminating a line screen from a linear light source and projecting the light rays through a Selfoc lens. The lamp is driven from a high frequency supply to achieve fast response and stable brightness. Striations are are eliminated by matching the power supply and lamp to prevent operation within certain current ranges. This creates a soft exposure modulation. As shown in the drawing, a line screen 10 is illuminated by a neon lamp 12. The light rays are projected through a Selfoc lens 14 onto the charged portion of the photoconductive surface 16 to record an electrostatic latent image corresponding to a line screen thereon. The neon light source illuminates the screen and the Selfoc lens projects the image onto the photoconductive surface. The demodulation of the Selfoc lens provides the soft or sine wave shape of the screen profile that is required. The Selfoc screen is less sensitive to tilt and skew due to the narrow illumination zone in the process direction. The linear source and narrow field angle of the individual lenslets reduces fanning of the projected screen.