TONER IMAGE INPUT SCANNER WITH SEQUENTIAL SCREENING
Original Publication Date: 1983-Oct-31
Included in the Prior Art Database: 2004-Apr-04
Xerox Disclosure Journal
In multi-function COPY, READ, WRITE systems employing the xerographic pro-cess, documents are read and the image content thereof converted to electrical signals or pixels in the READ mode. This is effected by raster scanning the document image after the document image has been developed on the photo-receptor and prior to transfer or erasure thereof, such scanning being effected by sweeping a laser beam across the developed image and capturing and converting the reflected light pattern to electrical signals. However, it appears that essentially no gray scale information can be achieved with this system in the case of continuous tone originals due to the blindness of the scanning laser to the height of the discrete toner piles that comprise the developed image. On the other hand, it has been found that gray scale is reasonably preserved when halftone documents are processed.