SELF-CORRECTING PRINTER-VERIFIER

摘要

TURN11-uu 11/13/84 Indicia having a requirement for a high degree of precision is printed onto a sheet and is scanned or read automatically shortly thereafter. Electronic control signals result from a comparison of the actually printed indicia with a pre-defined quality standard, and are used selectively to adjust command control signals to the printer to correct indicia printed thereafter. The leading edge of sheets to which the indicia is to be printed is precisely located by a light absorption detection or sensing mechanism which controls a sheet advance motor. The indicia printed, preferably bar code, is read by an optical bar code scanner traversing the printed code. The scanner is controlled by a scanner microprocessor control, and the printer is controlled by a printer microprocessor control which controls a comparison of the scanned code with a set quality standard to result in output signals to control the printer microprocessor control in a feedback loop to increase or to decrease the time of voltage application to printing elements in a thermal printer.