Confidential
Movement of print head unit
When the carriage motor rotates the carriage motor gear in the direction shown by the white
arrow, the driving force is transmitted sequentially to the carriage drive pulley and carriage
transmission belt, moving the head carriage assembly, which is fixed to the carriage
transmission belt, in the direction indicated by the white arrow. (See Figure D-5.)
Carriage drive pulley
Printing operation
Wire movement when printing one dot
1. When an electrical pulse is applied to the drive coil, the steel core is excited, and the
operation plate is pulled in the direction indicated by black arrow. At this time, the dot wire
is pressed against the operation plate by the force of the wire return spring. The force of the
operation plate pushes the dot wire out towards the platen (in the direction indicated by
black arrow).
2. The dot wire prints a dot when it strikes the platen through the ink ribbon and paper.
Rev.D
Carriage motor gear
TM-U675/U675P (with autocutter) Service Manual
Figure D-5
Print head unit
Carriage transmission belt
Head carriage assembly
Product Overview Appendix D-3