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
18-pin (9 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 1.5K Hz for 75
±
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
FX-2170 Service Manual
Operating Principles
Rev.A
2-1
Summary of Contents for FX-2170 - Impact Printer
Page 1: ...EPSON TERMINAL PRINTER FX 2170 SERVICE MANUAL EPSON 4005662 ...
Page 5: ...REVISION SHEET Revision Issued Date Revision Page Rev A October 13 1995 1st issued ...
Page 11: ...Figure 1 1 Exterior View of the FX 2170 Product Description FX 2170 Service Manual 1 2 Rev A ...
Page 140: ...FX 2170 Service Manual Troubleshooting Rev A 5 19 ...
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Page 156: ...Appendix FX 2170 Service Manual A 10 Rev A ...
Page 158: ...Appendix FX 2170 Service Manual A 12 Rev A ...
Page 159: ...Figure A 3 C166 PSB Board Assembly Circuit Diagram FX 2170 Service Manual Appendix Rev A A 13 ...
Page 160: ...Appendix FX 2170 Service Manual A 14 Rev A ...
Page 161: ...Figure A 4 C166 PSE Board Assembly Circuit Diagram FX 2170 Service Manual Appendix Rev A A 15 ...
Page 162: ...Appendix FX 2170 Service Manual A 16 Rev A ...
Page 167: ...Figure A 9 FX 2170 Exploded Diagrams 2 FX 2170 Service Manual Appendix Rev A A 21 ...
Page 168: ...Figure A 10 FX 2170 Exploded Diagrams 3 Appendix FX 2170 Service Manual A 22 Rev A ...
Page 169: ...Figure A 11 C S F Bin1 Exploded Diagrams 1 FX 2170 Service Manual Appendix Rev A A 23 ...
Page 170: ...Figure A 12 C S F Bin1 Exploded Diagrams 2 Appendix FX 2170 Service Manual A 24 Rev A ...
Page 171: ...Figure A 13 C S F Bin2 Exploded Diagrams FX 2170 Service Manual Appendix Rev A A 25 ...
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