Head Balance Adjustment Mechanism - Citizen CLP-621 Technical Manual

2-1. Operation of Each Mechanism

2-1-6. Head Balance Adjustment Mechanism

The major components of the head balance adjustment mechanism are:
(a) Head balance lever
(b) Head balance cam
The head balance adjustment mechanism is used to eliminate uneven printing density on media.
The head balance adjustment is accomplished by changing the right side head pressure according
to media width to be used. To adjust, the blue media width adjustment dial (Head Balance Cam) is
used. When narrow width media is used, the dial should be set toward "0" to give weaker pressure.
When wide width media is used, it should be set toward "9" to give stronger pressure.
When narrow media is used (need to give weak pressure):
The Head L Spring and Head R Spring act to press the Head SA against the Platen SA. If the
same pressure is given by both springs, since no media exists on the right side of the Head SA,
the Head SA will slant to the right, resulting in uneven printing density. The part "A" of the Head
Balance Lever is pushed against the cam part by the Head R Spring and it moves up step by step
as the media width adjustment dial is turned toward "0". As it moves up, the Head R Spring is
pressed with weaker force by the Head Balance Lever, and the right side pressure against the
Head SA is decreased, resulting in even printing density. You need to align the dial number
according to the media width to be used. (Smaller number for narrower media)
When wide media is used (need to give strong pressure):
The same principle applies to wide media. However, in this case, the media width adjustment dial
should be turned toward "9". Then the part "A" of the Head Balance Lever moves down to apply
stronger pressure to the Head SA. (Larger number for wider media)
For narrow media
Spring, Head L
(Fixed)
SA, Head
Ribbon
Media (Narrow width)
For wide media
SA, Head
Ribbon
Media (Wide width)
CLP-621 & CLP-631
(c) Head L/R Spring
Spring, Head R
(Movable)
Lever, Head
Balance
SA, Platen
2-14
Taward "0"
Weak
Cam, Head Balance
A
(Media Width Adjustment
Dial)
Strong
Taward "9"