Canon Color Bubble Jet BJC-5000 Series, Руководство по обслуживанию

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BJC-5000
Part 4: Technical Reference
DRAM controller
The DRAM controller controls the 9-bit address/16-bit data bus of the 4M-bit
DRAM, and also performs the read/write control, RAS/CAS control, and refresh
control.
Buffer controller
The buffer controller automatically writes and reads the print buffer in the DRAM,
manages the remaining capacity of the print buffer, and clears the data after it is
read.
Printhead controller
The printhead controller sends the print data read from the print buffer in the
DRAM to the printhead. At the same time, the printed dots are counted for variable
control of the HeatENB signal pulse width (Pre/main pulse width).
The head-driving signals consist of block enable signals (BENB 0, 1, 2) and
odd/even enable signals (ODENB/EVENB) which are used in common for both LEFT
and RIGHT BJ cartridges, and heat enable signals (HENB0L, 1L, 2L, 3L for LEFT;
HENB0R, 1R, 2R, 3R for RIGHT) which are used separately for the LEFT and RIGHT
BJ cartridges. The block enable signals and odd/even enable signals specify the
block for the time-shared drive. The heat enable signals control the conduction time
of the eject heater.
I/O port
Signals for the setting statuses determined by the POWER button , RESET button ,
auto-alignment sensor, head temperature sensor, head ID, paper end sensor, home
position sensor, pick-up roller sensor, and purge sensor are input through the input
ports.
Signals for operations such as
POWER indicator , ERROR indicator , buzzer, BJ
cartridge detection, and head-driving voltage control are output from the output
ports.
3) Control ROM (U2)
The 8M-bit control ROM contains the printer control program.
4) DRAM (U11)
Controlled by the MPU & printer controller, the 4M-bit control DRAM is used as a
print buffer and working area.
5) Reset IC (U6)
This IC detects the power voltage when power is turned on or during an
instantaneous power failure and resets the MPU & printer controller.
6) EEPROM (U10)
Controlled by the MPU & printer controller, the 1K-bit Electrically Enable and
Programmable ROM (EEPROM) stores various function settings, the total count of
printed sheets, and total waste ink amount.