Scanner as test print densitometer for compensating overall process drift and nonuniformity
US5546165A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 5, 1994 |
| Grant date | Aug 13, 1996 |
| Priority date | — |
| Expiry date | Oct 5, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03G2215/00316
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An electrostatographic copier or copier/printer apparatus and method for calibrating same with an improved means for adjusting for process control parameters is described. The apparatus includes a scanner for scanning an original document to be copied and for generating signals representing a density characteristic of images on the document. An electronic writer responsive to scanned signals modulates charge on an electrostatographic recording member to form a latent electrostatic image. The latent image is developed and transferred to a record member. Them are provided further means responsive to rescanning of the record member by the scanner for generating adjustment signals for correcting for calibration errors in processing of an image, and the writer is responsive to the adjustment signals. The writer may thereby correct for nonuniformities in a direction transverse to said process direction. In a further calibration step, there are generated adjustment signals that are responsive to scanning by the scanner of a halftone step tablet on a record member. The adjustment signals are used to generate adjusted halftone rendering patterns for printing by the writer. In a further cali…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.