The InnovationQ application will be updated on Sunday, May 31st from 10am-noon ET. You may experience brief service interruptions during that time.
Browse Prior Art Database


IP.com Disclosure Number: IPCOM000024142D
Original Publication Date: 1979-Oct-31
Included in the Prior Art Database: 2004-Apr-02

Publishing Venue

Xerox Disclosure Journal


One-dimensional additive halftone screens cannot achieve linear TRC (tone reproduction curve) over a density range larger than unity. To increase the linear density range, two basic methods have been proposed; one is to image on the xerographic drum a two-dimensional halftone screen by flashing on and off a halftone pattern as the drum rotates, and the second method is to use an addressable screen whose amplitude is made dependent on the image content. It can be produced by a scanning laser beam whose irradiance is modulated by the image content The beam either produces the halftone pattern directly, or it is used to scan a halftone mask. The second method can also be used to perform low-resolution image corrections like color masking or unsharp masking.