Back to results
US 4,052,715 AGranted
Digital half-tone grey scale expansion system
AssigneeXerox Corporation
InventorWilliam Streifer
Life of this patent
Estimating the term…
Loading patent…
Loading patent…
AssigneeXerox Corporation
InventorWilliam Streifer
Estimating the term…
Method and apparatus for expanding the number of grey scale values in a digital flying-spot scanning system. The scanned recording medium is divided into a plurality of unit cells, each of which is assigned a desired grey scale value, and each unit cell is further divided into a plurality of subcells formed by a plurality of adjacent portions of scan lines comprising digitally controlled segments. The grey scale value of the unit cell is dependent upon the portion of the subcells within the unit cell which are activated or deactivated by the scanning beam. Additionally, the number of grey scale values between particular numbers of activated subcells is expanded by providing varying patterns of predetermined numbers of subcells within the unit cell with the varying patterns producing the optical effect of varying grey scale levels.
A variable half-tone image generating system for use in a flying-spot scanning system comprising:
A method for providing a number of grey scale values on an image surface from a fixed number of addressed areas of said image surface comprising the steps of:
Dependencies are inferred from the claim text.