Control Circuit Operation; Control Circuit Operation Overview - Epson LG1-1070 Service Manual

2.3 CONTROL CIRCUIT OPERATION

The control circuit consists of two boards: the C062 MAIN board, which acts as the main board, and
the C062 PNL board, which acts as the control panel board. This section describes how these boards
work.

2.3.1 Control Circuit Operation Overview

The printer CPU is an 8-bit CPU TMP90C04 1 running at 10 MHz. It oversees control of all the
components of the printer. The E05A50 gate array contains various memory management functions
that control the assignment of the memory and I/O areas. Rationalization and simplification of the
circuitry is achieved through use of the STK-6022B. which holds all the driver circuits for driving the
PRINTER MECHANISM on a single chip. Figure 2-l 7 shows the control circuits in block diagram form.
CO62 PNL Board
I
Vref
Circuit
CR MOTOR, PF DETECTOR ASSY.,DETECTOR ASSY.,DETECTOR ASSY., DETECTOR ASSY., DETECTOR ASSY
I
PRINTER MECHANISM
GA
DETECTOR ASSY., RELEASE
DETECTOR ASSY., RELEASE Release sensor
DETECTOR ASSY., PE, FRONT Front paper-out detector (positioned in front of the PRINTER MECHANISM)
DETECTOR ASSY., PE, REAR
CO62 MAIN Board
HP PE, FRONT
Gate array
Platen gap sensor
Rear paper-out detector (positioned behind the PRINTER MECHANISM)
Figure 2-17. Control Circuit Block Diagram
PE, REAR
DETECTOR ASSY., HP Home position sensor
MOTOR, CR
MOTOR, PF
2-13
PLATEN RELEASE
Carriage motor
Paper advance motor
REV.-B
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