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REGISTRATION CORRECTION FOR ROTATING DRUMS

IP.com Disclosure Number: IPCOM000023732D
Original Publication Date: 1978-Dec-31
Included in the Prior Art Database: 2004-Mar-31
Document File: 2 page(s) / 330K

Publishing Venue

Xerox Disclosure Journal

Abstract

In high speed, xerographic printers utilizing a rotating character drum, a non-synchronism may exist between the "regmark" pulses which occur several times per revolution of the xerographic drum and "linestart" pulses which occur once per revolution of the character drum. To correct any non-synchronism, the detected linestart period is split into a convenient number of time segments by a 1/N pulse generator 4 which is coupled through an AND gate 6 to a counter 8. A correction D/A function decoder 10 coupled to the counter stages supplies a correction signal to a correction pulse generator 12 which supplies a control signal to the drive circuit 14 of the synchronous motor 16 driving the character drum 18. The xerographic drum 20 is also driven by a synchronous motor 22.

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XEROX DISCLOSURE JOURNAL

REGISTRATION CORRECTION FOR
ROTATING DRUMS
Walter C, Davie

~22

Proposed Classification
U.S. Cl. 318/301
Int, Cl. H02k 27/20

In high speed, xerographic printers utilizing a rotating
character drum, a non~synchronism may exist between the
"regmark" pulses which occur several times per revolution of
the xerographic drum and "linestart" pulses which occur once
per revolution of the character drum. To correct any non~-
synchronism, the detected linestart period is split into a
convenient number of time segments by a 1/N pulse generator 4
which is coupled through an AND gate 6 to a counter 8. A
correction D/A function decoder 10 coupled to the counter
stages supplies a correction signal to a correction pulse
generator 12 which supplies a control signal to the drive
circuit 14 of the synchronous motor 16 driving the character
drum 18. The xerographic drum 20 is also driven by a
synchronous motor 22.

BOX

Volume 3 Number 6 November/December 1978 415

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REGISTRATION CORRECTION FOR ROTATING DRUMS (Cont~d)

The number of time segments following a regmark is loaded into
the counter. Following the arrival of the linestart pulse,
the counter is frozen in its last states The character drum
motor current is later interrupted during the regmark period
for a time which is a function of the count held in the
counters Thus, a count of eight (when N is sixteen) might
represent the nominal position of the regmark-linecou...