Ribbon Drive Mechanism - OKIDATA ML590 Service Manual

2.2.04 Ribbon Drive Mechanism

Black Ribbon Drive Operation
The ribbon drive mechanism feeds the ribbon in synchronization with the spacing operation. The
force required to drive the ribbon is obtained from the space motor.
The ribbon drive mechanism is composed of the following items.
Ribbon drive gear assembly
Ribbon gear (located on the space motor assembly)
Ribbon cartridge
A continuous loop ribbon with uni-directional feed is used. Ink is supplied from an ink tank, which
is built into the ribbon cartridge.
When the space motor turns, the ribbon gear on the spacing motor shaft rotates. The rotation is
transmitted via a combination of gears, from the ribbon drive gear assembly to the drive gear in
the ribbon cartridge.
Although the space motor moves in both the forward and reverse directions during bi-directional
printing, the gears in the ribbon drive assembly maintain uni-directional ribbon feed by switching
the rotation direction of the gears.
Copyright 1997, Okidata, Division of OKI America, Inc. All rights reserved. See the OKIDATA Business
Service Guide ML590/ML591
Chapter 2 Principles of Operation
Page: 76