APPENDIX 1

Construction of MX-80 Type II

and MX-80 F/T Type II

The EPSON MX-80 Type I I and MX-80 F/T Type II dot matrix printers (hereinafter referred to as “Type II Printer”) consist of the following three major functional blocks.

(1)Printer Mechanism

(2)Control Circuit Board

(3)Power Circuit

These three blocks are housed in a plastic case and are connected to one another.

1.1. Printer mechanism

The printer mechanism has been developed by EPSON Shinshu Seiki CO ., Ltd., with the latest technology in the precision and electronic industry fields.

The printer mechanism contains two stepper motors. One is to move the print head to the next print column position, and the other is to advance the paper.

(1)Stepper motor for head carriage

The stepper motor for head carriage is controlled under LSI “8041” called “slave CPU”. The CPU knows the current printing position at any given time and the print head is stopped at the last printing position. Then, the CPU seeks the shortest travel way to the next print line.

This feature and bidirectional printing enable the Printer to perform the logical seeking function which minimizes the head travel time to the next print line.

(2)Stepper motor for paper feed

Paper is fed by the stepper motor, like the head carriage. One complete

rotation of the stepper motor corresponds to 1/3 inch paper advance, In the

Type II Printer, the operator can select any paper feed length under software

control.

 

 

 

(3) Print

head

 

 

The

print

head has

9 dot wires to form 9 x 9 dot matrix characters.

9 wires

form

more

legible characters than those formed by 7 wires. The print

head

for

the

printer

mechanism is quite compact.

1.2. Control

circuit

board

 

 

In

this paragraph,

the

printer

LSI circuitry

is outlined. The control circuit diagram

is

shown in

Fig. Al-l,

and the

driver circuit

diagram in Fig. Al-2.

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