Microprocessor controlled d.c. motor for controlling printing means

Abstract

An improvement in combination with apparatus including rotary means, wherein the rotary means includes a periphery having indicia printing means and is adapted for feeding a sheet in a path of travel. The improvement comprises: a first device for sensing a time interval during which a sheet having a leading edge is linearly displaced a predetermined distance in the path of travel; a d.c. motor coupled to the rotary mean for rotation of the rotary means; a second device for sensing angular displacement of the rotary means and a computer coupled to the first and second sensing devices and to the d.c. motor; wherein the computer responds to the first sensing device for providing respective amounts representative of desired angular displacements of the rotary means during successive sampling time periods, responds to the second sensing device for providing respective amounts representative of actual angular displacements of the rotary means during successive sampling time periods, compensates for the difference between desired and actual angular displacements and generates a d.c. motor control signal for controlling rotation of the motor to cause the linear displacement of the indicia printing means to initially engage the sheet in the path of travel a predetermined marginal distance from the leading edge of the sheet.

Dependencies are inferred from the claim text.