Control of halftone and solid area image quality by way of a halftone discharge ratio
AssigneeXerox Corporation
InventorRobert E. Grace
Life of this patent
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Abstract
In an electrostatic and development control in a printing apparatus, unwanted variation in dot size and shape may be stabilized and the DMA variability under halftone control may be decreased, by use of a novel halftone discharge ratio (HTDRmidtone) along with the conventional actuators of development potential, cleaning potential, and exposure level. A three-input, three-output MIMO control system may be constructed to deliver superior regulation of halftone and solid area image quality with use of control algorithms that are based on the halftone discharge ratio and with use of as few as two developed halftone test patches.
Claims7
In an imaging apparatus having an imaging member and electrostatic and development subsystems, a control system responsive to imaging member voltage potential, developed mass per unit area on the imaging member, and a halftone discharge ratio based upon a midtone level (HTDRmidtone) for adjustment of at least one of the electrostatic and development subsystems, wherein the halftone discharge ratio is determined as follows:
- HTDRmidtone=(Vlopatch−Vmidpatch)/(Vlopatch−Vsolid)
- wherein Vlopatch is representative of the surface potential of a selected low density halftone latent image, Vsolid is representative of a voltage at which a desired solid area developed mass (DMA) level is achieved, and Vmidpatch is representative of the surface potential of a selected midtone latent image.
Dependencies are inferred from the claim text.