Color Ribbon Shift Mechanism - OKIDATA ML590 Service Manual

Color Ribbon Shift Mechanism

Items of the color ribbon unit option are listed below.
Color shift unit
Color ribbon (4 colors)
Four colors can be selected by sliding the color ribbon holder up or down. Here is a description of
how the ribbon holder is shifted.
As the space motor moves, idle gear C on the ribbon drive unit rotates. Idle gear C rotates the
color idle gear, located in the color shift unit.
When the color-P signal from the main control board activates the pranger magnet, the magnet
attracts the armature. This causes the reset spring to force the change gear downward. The color
idle gear rotates the change gear, which turns the color change gear. The color change gear turns
the color cam shaft. The rotation of the color cam shaft moves the color ribbon holder up/down to
select the desired ribbon color.
There is a cam at each setting of the color change gear. When the change gear is at the top of
the cam, the change gear disengages from the color change gear. At this time, the armature
resets, changing the color band selection by one setting.
Service Guide ML590/ML591
Chapter 2 Principles of Operation
Page: 77