DOT PRINTER
JAN. 1997
MD-910
(without price)
TECHNICAL MANUAL
Features
The MD-910 series is a dot matrix compact printer that uses two serial print heads.
This printer has been developed as an output terminal for various applications such as POS terminals,
measuring/analyzing equipment, medical equipment and communication data equipment, and has
been designed to be as compact as possible.
· Compact and lightweight
· High-speed printing of up to 2.5 lines/sec. (for MD-910) or 1.8 lines/sec. (for MD-911)
· Clear printout with high resolution of 8 dots/mm
· Paper width of print head
· Longer life of print head
· Simple mechanism for high-reliability
Contents
1 Printer usage and Care ..................................................................................................................... 1
2 Specifications/Operating principles ................................................................................................... 2
2-1 Specifications ............................................................................................................................ 2
2-2 Outline of mechanism ............................................................................................................... 3
2-3 Mechanism and operation principles ........................................................................................ 3
2-3-1
Power transmission mechanism ................................................................................... 3
2-3-2
Sensor mechanisms ..................................................................................................... 4
2-3-3
Print head mechanism .................................................................................................. 5
2-3-4
Paper feed mechanism ................................................................................................. 8
2-3-5
Ribbon cartridge drive mechanism ............................................................................. 11
2-4 External connection terminals ................................................................................................. 11
2-4-1
Terminal arrangement ................................................................................................ 11
2-4-2
Terminal mechanism .................................................................................................. 12
2-4-3
Terminal circuit diagram ............................................................................................. 12
3 Disassembly/Reassembly ............................................................................................................... 13
3-1 Tools
.................................................................................................................................... 13
3-2 Disassembly procedure .......................................................................................................... 13
3-3 Assembly procedure ............................................................................................................... 14
3-3-1
Setting paper feed solenoid assembly ........................................................................ 14
3-3-2
Setting the head assembly ......................................................................................... 15
3-3-3
Setting the paper feed assembly ................................................................................ 16
3-3-4
Setting the main body assembly ................................................................................. 18
4 Parts list
.................................................................................................................................... 26
5 Exploded view ................................................................................................................................. 28
-- 1 --
1 Printer usage and Care
(1) Use recommended register paper. Otherwise, printing quality and the life of the print head will not be
guaranteed. The width of paper must meet the specifications.
(2) Never allow a mechanical impact (including the entry of foreign matter) to the print head surface.
(3) Any dust on the print head surface must be wiped off by an applicator soaked in ethanol or the
equivalent.
(4) The dedicated ribbon cartridge should be taken off when the printer is carried or not used for a long
period.
(5) Do not feed current to the print head if it is wet or moist. If current is fed, the print head may be
damaged. If the print head is wet or moist, dry it fully and then start printing.
(6) Inserting register paper
· Cut the top end of the register paper
straight (it should never be fluffed or bent)
and insert it.
· When the top end of the register paper
comes out of the print head, check that it
is set straight and then pull it.
(7) Removing register paper
· Before removing the register paper, be sure
to stop feeding current to the print head.
· Pull out paper straight in the direction of
paper exit.
-- 2 --
Item
Specifications
Printing method
Dot matrix system
Printing direction
Unidirectional printing
Printing speed
2.5 lines/sec.
± 20 %; DC 5.0 V, 25 °C in
continuous printing
Printing format
Number of dots
144 dots/line
Character configuration (5 + 1)
× 8
Number of columns
24
Paper feeding
Paper feeding pitch
3.52 mm (10 dots/line)
Rapid feed rate
5 lines/sec.
± 20 %; DC 5.0 V, 25 °C in
continuous printing
Inking
Dedicated cartridge (black or purple)
Detection
Dot pulse
Photointerrupter
Reset pulse
Leaf switch detector
Paper feeding solenoid Drive voltage
DC 5.0 V
Resistance
7
± 3 (temperature: 25 °C)
Printing solenoid
Drive voltage
DC 5.0 V
Resistance
1.7
± 0.3 (temperature: 25 °C)
Motor
Type
DC brush motor
Drive voltage
DC 5.0 V
Max. current
Approx. 1 A
Average current
0.3 A or less; DC 5.0 V, 25
°C in continuous
printing
Paper
Type
Plane or recommended paper
Paper width
57.5 mm
Cut sheet
45 to 55 kg
(thickness: 0.06 to 0.085 mm)
Copies
Original paper (34 kg) + single copy (34 kg)
(Total thickness: 0.13 mm or less) Non-carbon
paper
Life of print head
1,500,000 lines
Exterior dimensions
90 (w)
× 45.5 (d) × 15.8 (h) ± 0.5 mm
(excluding paper feeding nob and feet)
Weight
105 g
± 10 %
2 Specifications/Operating principles
2-1
Specifications