Mailing machine including printing drum control system

(19)

(11)

EP 0 547 922 A3

(12)	EUROPEAN PATENT APPLICATION

(88)	Date of publication A3:
	05.04.1995 Bulletin 1995/14

(43)	Date of publication A2:
	23.06.1993 Bulletin 1993/25

(21)	Application number: 92311664.4

(22)	Date of filing: 21.12.1992

(51)	International Patent Classification (IPC)⁵: G07B 17/00, G07B 17/02

(84)	Designated Contracting States:
	CH DE FR GB LI

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Priority:

19.12.1991 US 810258
19.12.1991 US 810597

(71)	Applicant: PITNEY BOWES INC.
	Stamford Connecticut 06926-0700 (US)

(72)	Inventors:
	Eckert, Alton B., Jr. New Fairfield, CT 06812 (US) Gallagher, Dennis M. Danbury, CT 06810 (US) Pfeifer, Thomas M. Bridgeport, CT (US) Schoonmaker, Richard P. Wilton, CT 06897 (US)

(74)	Representative: Cook, Anthony John et al
	D. YOUNG & CO. 21 New Fetter Lane London EC4A 1DA London EC4A 1DA (GB)

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References cited: :

(54)	Mailing machine including printing drum control system

(57) A mailing machine base 12 has a postage meter 14 mounted thereon. The meter includes a postage printing drum 64 having a home position. The base comprising, structure for moving the drum, a d.c. motor 110 for driving the drum moving structure, a microprocessor 122, a power switch connected between the d.c. motor and microprocessor, a comparator 125 connected between the microprocessor and d.c. motor for receiving therefrom a signal corresponding to the back e.m.f. voltage of the d.c. motor and providing a comparison signal to the microprocessor. The microprocessor is programmed for: providing a reference voltage signal for the comparator corresponding to a desired back e.m.f. voltage for causing the d.c. motor to drive the postage printing drum at t desired constant velocity, energizing the power switch with a first signal for causing the d.c. motor to accelerate the drum at a substantially constant rate to substantially the desired constant velocity from the home position thereof during a first predetermined time interval, determining whether the back e.m.f. is greater than the reference voltage, energizing the power switch with the first signal for a second predetermined time interval if the back e.m.f. voltage is not greater than the reference voltage, and energizing the power switch with a second signal for a third predetermined time interval if the back e.m.f. voltage is greater than the reference voltage and delaying energizing with the second signal if the back e.m.f. voltage is not greater than the reference voltage, thereby causing the d.c. motor to continue driving the drum at substantially the desired constant velocity.

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