Operating Principles
LX-105O+
Service Manual
Table 2-3. Functions of the Main
IC
and Circuits
IC
and Circuits
Looation Functions
Receives data from the host computer and loads the data to the
input buffer in RAM. Expands the input data held in the buffer to
vPD781
OHG
2C
create image data. Loads this image data to the image buffer in
RAM. Transfers the image data to the
printhead
drive circuit. Also
controls various parts of the printer mechanism, such as the
motors.
The gate array
E05A30
functions areas follows
1. Parallel l/F
2. Address decoder
E05A30
3B
3. Data address multiplexer
4. PF motor control
5. CR motor control
6. Control panel LED drive
7.
Printhead
drive
oontrol
ROM
3C
This ROM memory program and fonts.
RAM 3D
This RAM is used as an input data buffer and image buffer for
expanding data, and as working area for the program.
EEPROM
Ic
The
EEPROM
has a 256-bit memory, and remembers the current
paper position.
The paper feed motor drive circuit drives the paper feed motor.
Paper feed motor
The paper feed motor is a 4 phase-step motor. The rotation of the
ā€”
drive circuit
motor (position and speed) is controlled by outputting the phase
switching signal by the
E05A30
gate array.
The carriage motor drive circuit drives the carriage motor. The
Carriage motor
carriage motor is a 4 phase-step motor. The rotation of the motor
ā€”
drive circuit
(position and speed) is controlled by outputting the phase
switching signal by the
E05A30
gate array.
2.3.2.1 Reset Circuit
11-tis
circuit generates the signal that initializes the printer, and is made by monitoring the +5 and
+24V
voltages when the power is switched ON and OFF.
The reset signal line is
comect
to the CPU and gate array 3B.
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Figure 2-13. Reset Circuit
RESET
2-1o
Rev.
A