Postage meter apparatus and process employing computer controlled D.C. motor for indexing postage value changing means

摘要

An improvement in combination with a postage meter (10) including a rotary postage printing drum (38) having apparatus (43,44) for changing respective postage values to be printed, and including apparatus (40a,40b,76,90) for actuating the changing apparatus, there is provided an improvement for indexing the changing apparatus into engagement with the actuating apparatus. The improvement comprises: a d.c. motor (120) coupled to the drum (38) for rotation of the drum (38); a device (126) for sensing angular displacement of the drum (38); and a computer (500) coupled to the sensing device (126) and to the d.c. motor (120); wherein the computer (500) provides respective amounts representative of desired angular displacements of the drum (38) during successive sampling time periods, responds to the sensing device for providing respective amounts representative of actual angular displacements of the drum (38) 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 (120) to cause the changing apparatus to be indexed into engagement with the actuating apparatus.