Patent ID: 8189026
Filing Date: 2012-05-29
Classification: G03G

Abstract:
1. A method of correcting print images in an electrophotographic printer wherein an image formed by a print head on a peripheral surface of a photoconductor drum is transferred and printed on a sheet of paper, characterized in that it comprises the steps of: furnishing the print head with a standard tacho signal in the form of pulses and thereby printing on a sheet of paper a check mark for each given number of pulses of the standard tacho signal while the photoconductor drum makes one rotation; by a camera, detecting a periodic deviation in each spacing between successive such check marks; in response to the deviation in each spacing between the successive check marks, varying the pulse width of pulses of the standard tacho signal for each spacing between the successive check marks, thereby to provide a modified tacho signal; and effecting printing thereafter based on the modified tacho signal.