THEORY OF OPERATION
4.
Mechanism
4-1. Print Head Mechanism
The print head consists of 9 needle wires and 9 print solenoids.
The following explains how each needle wire operates during printing.
(1)
When the print solenoid is energized, the clapper is attracted by the iron core and the needle wire is driven toward
the platen.
(2)
This needle wire hits the platen via the ink ribbon and paper. A single dot is printed on the paper.
(3)
When the print solenoid is de-energized, the needle wire is returned to its original position by rebound energy and
spring and clapper holder (leaf spring) force.
Spring
Stopper
Clapper holder
Clapper
Fig. 2-4 Outline of Print Head Mechanism
Paper guide
Ink ribbon
Needle wire
Needle Guide
Subguide
Iron core
Print solenoid
– 22 –
Paper
Platen