Appendix D-8
Product Overview
Rev.D
Confidential
Home position detection mechanism
The home position detection mechanism is located at the left end of the head carriage assembly.
This mechanism keeps track of the head carriage assembly movement position. The initial
setting is made by sensing the detection plate at the rear of the head carriage assembly.
The home position detector consists of an LED and photo IC. When the head carriage assembly
is moved, the detection plate passes between the LED and photo IC. The photo IC output level
changes when the light rays are interrupted. This change in output level is used as a detection
signal for the head carriage movement position.
Figure D-10
Carriage detection mechanism
The carriage detection mechanism uses a rotary encoder interlocked to the carriage motor gear
to detect abnormal carriage motor rotation.
This mechanism is comprised of the carriage drive transmission gear and carriage detector,
which are located on the carriage motor shaft.
The carriage detector consists of an LED and phototransistor.
The driving force generated by the carriage motor is transmitted to the carriage motor gear,
carriage drive pulley, carriage belt, carriage transmission pulley, and the carriage drive
transmission gear, which is located at an equal interval on the inside of the gear, where the
screening plate is located. When the carriage drive transmission gear is rotated by the driving
force of the carriage motor, the screening plate passes between the LED and phototransistor.
The output level of the phototransistor changes at this time, since the light rays are interrupted.
This output level is used as the detection signal for carriage motor rotation.
Figure D-11
GND
High
+5V
GND
Low
When light is
interrupted
When light is emitted
Printer side
Head carriage detector assembly
Signal level at point A
GND
High
+5V
GND
Low
When light is
interrupted
When light is emitted
Printer side
Screening plate
Signal level at point A
Содержание U675 - TM Color Dot-matrix Printer
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Страница 4: ...Confidential ii Revision Table ...
Страница 34: ...1 22 Troubleshooting Rev D Confidential ...
Страница 168: ...2 134 Assembly and Disassembly Rev D Confidential ...
Страница 180: ...Appendix A 2 Service Tools and Lubricants Rev D Confidential ...
Страница 270: ...Appendix D 82 Product Overview Rev D Confidential ...
Страница 322: ...Appendix J 2 Screw Types Rev D Confidential ...
Страница 324: ...Appendix K 2 Parts Layout Rev D Confidential Main Circuit Board Unit Solder Side memory board ...
Страница 325: ...SEIKO EPSON CORPORATION Printed in Japan EPSON ...