Improved halftone screen and method for making same

摘要

In order to improve the printability of a periodic halftone screen, the amount of growth of the halftone dots in a halftone screen is modulated as a function of tone in a tone selective way that is different for at least two halftone dots. In one embodiment for low densities the number of dots of substantially equal area is modulated, and for high densities the area of dots is modulated. The layout of a photomechanical contact screen and an electronic threshold matrix for obtaining the specific halftone screen is defined.