Printhead Control - Oki PACEMARK 4410 Service Manual

2.1.8

Printhead control

The printhead is controlled by the Main LSI and NHDC LSI.
Printing is synchronized with the ITOUT signal from the NHDC LSI.
Control Board
MPU
A/D bus
The NHDC LSI outputs the dot timing1 signals (DT1:1~18) and the dot timing2 signals (DT2:1~18),
and the driver IC drives each dot magnet. These signals are output from the NHDC LSI after the
following corrections for final driving time determination inside the LSI:
(1) Correction for the number of pins driven
The driving time is corrected according to the number of pins driven at the same time out of
18 pins.
(2) Correction according to adjacent pin drive timing
The driving time is adjusted by checking whether the pin adjacent to the pin to be driven is
driven on the previous timing.
(3) Correction for head gap
The driving time is corrected according to the head gap.
Driver Board
NHDC LSI
Print Data
HEAD1-P~
HEAD18-P
Main LSI
TFA-N
TFD-N
Figure 2.11
DRIVER
Print Data
HEAD1~
HEAD18
24
Print Head