Abstract: An erase bar for a xerographic printer, copier or the like has a row of light emitting diodes for illuminating a row of pixels across the photosensitive medium of the printer. Each LED is located in the bottom of a cavity. Next to the bottom of the cavity are concave reflective walls which reflect light emitted transversely from the LED toward an open end of the cavity. Reflective walls of the cavity provide multiple bounces of some of the light. Absorptive walls nearer the open end of the cavity absorb some of the light. These features combine to illuminate a pixel of desired shape and with approximately uniform intensity of illumination. Additional uniformity may be provided by passing the illumination through a window that is at least partly absorbing for smoothing out differences in intensity.