Spacing Operation - OKIDATA ML320 Service Manual

Page: 27
Service Guide ML320/ML321
Chapter 2 Principles of Operation

2.3.04 Spacing Operation

Spacing Motor Control
The motor control LSI produces the spacing motor phase signals SP-U, SP-V, SP-W and the
overdrive signal SPD-A in accordance with spacing commands from the microprocessor.
The SPD-A signal is a fixed period pulse signal whose pulsewidth is controlled by the program. This
signal is used to control motor drive time.
The signal SP ON/OFF is used at acceleration/deceleration, when a large amount torque is
required.
Spacing Motor Encoder Disk / Photosensor
As the spacing motor is driven, the signals PHASE-A and PHASE-B are generated by the
photosensor / encoder disk (which is mounted to the spacing motor).
The motor control LSI divides the frequency of these signals in accordance with the
selected print pitch. The LSI generates the IPT-N signal, which provides dot-on timing
and carriage position detection.
Copyright 1997, Okidata, Division of OKI America, Inc. All rights reserved. See the OKIDATA Business
Partner Exchange (BPX) for any updates to this material. (http://bpx.okidata.com)