2.1 PRINTER MECHANISM OPERATION
This section describes the printer mechanism and explains how it works.
2.1.1 Printing Mechanism
The printing mechanism is composed of the printhead, ink ribbon, and ribbon mask. The printhead is an
24-pin (12 pins
×
2) head for impact dot printing. To improve the durability of the dot wires, they are
arranged on the printhead in 2 columns.
Each wire has its own drive coil, which causes the wire to move in and out of the printhead to print each dot.
The four steps below describe how these driving wires work.
1.
A drive signal, transmitted from the control circuit to the printhead drive circuit, is converted to the
proper printhead driving voltage, which energizes a corresponding coil. The energized coil then causes
the iron core to become magnetized.
2.
The magnetic force draws the actuating plate toward the core, and the dot wire, which is connected to
the core, rushes toward the platen.
3.
When the dot wire impacts the platen, pressing against the ribbon and paper, it prints a dot.
4.
When the driving voltage stops energizing the coil, the magnetic force from the iron core vanishes. The
actuating plate returns to its original position (the position before coil was energized) with spring action.
The dot wire also returns to its original position.
This is the sequence used to print a single dot.
The mechanism is equipped with a built-in thermistor for head temperature detection. The temperature
detected by the thermistor is converted to an electric signal and fed back to the control circuit.
The printhead is also used as a beeper. Head driving coils move all the dot wires back and forth at a
frequency of 1.98 KHz for 65
±
5
µ
sec without impacting the platen, so that the wires vibrate.
The vibrating dot wires create the sound used for beep codes.
Platen
Ribbon Mask
Ribb on
Dot Wire
Wire Resetting Spring
Stopper
Actuating
Plate
P a p e r
Iro n Core
Head Driving Coil
Actuating Spring
Figure 2-1 Printhead Operation Principles
LQ-2170 Service Manual
Operating Principles
Rev.A
2-1
Содержание LQ-2170
Страница 1: ...EPSON TERMINAL PRINTER LQ 2170 SERVICE MANUAL EPSON 4005735 ...
Страница 5: ...REVISION SHEET Revision Issued Date Revision Page Rev A December 5 1995 1st issued ...
Страница 11: ...Figure 1 1 Exterior View of the LQ 2170 Product Description LQ 2170 Service Manual 1 2 Rev A ...
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Страница 127: ...1 Abnormal CR Operation LQ 2170 Service Manual Troubleshooting Rev A 5 5 ...
Страница 141: ...LQ 2170 Service Manual Troubleshooting Rev A 5 19 ...
Страница 156: ...Appendix LQ 2170 Service Manual A 10 Rev A ...
Страница 157: ...A 4 CIRCUIT DIAGRAMS Figure A 2 C165 MAIN Board Assembly Circuit Diagram LQ 2170 Service Manual Appendix Rev A A 11 ...
Страница 158: ...Appendix LQ 2170 Service Manual A 12 Rev A ...
Страница 159: ...Figure A 3 C165 PSB Board Assembly Circuit Diagram LQ 2170 Service Manual Appendix Rev A A 13 ...
Страница 160: ...Appendix LQ 2170 Service Manual A 14 Rev A ...
Страница 161: ...Figure A 4 C165 PSE Board Assembly Circuit Diagram LQ 2170 Service Manual Appendix Rev A A 15 ...
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Страница 164: ...Figure A 6 C165 PSB Board Assembly Component Layout Appendix LQ 2170 Service Manual A 18 Rev A ...
Страница 165: ...Figure A 7 C165 PSE Board Assembly Component Layout LQ 2170 Service Manual Appendix Rev A A 19 ...
Страница 166: ...A 6 EXPLODED DIAGRAMS Figure A 8 LQ 2170 Exploded Diagrams 1 Appendix LQ 2170 Service Manual A 20 Rev A ...
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Страница 172: ...Table A 15 Part No Reference Table Appendix LQ 2170 Service Manual A 26 Rev A ...
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Страница 175: ...EPSON Printed in Japan 95 12 05 S ...