Epson TM-U675 - MICR Reader Operating Principles

Appendix D-62 Product Overview Rev.D
Confidential
The MICR solenoid is not driven when MICR_SOL2 is HIGH. MICR_SOL1 is the solenoid drive
signal. This is to prevent a short when the transistors go on at the same time.
The MICR solenoid drive circuit is shown below.
Figure D-58
MICR reader operating principles
MICR stands for “magnetic ink character recognition.” Unlike conventional printing ink,
magnetic ink includes iron powder or some other magnetic element, which gives the ink itself
magnetic properties.
Application of a magnetic field on one side of characters printed in magnetic ink on a check
causes the characters to be magnetized, as shown in the illustration below.
Figure D-59
24V 13V
MICR_SOL1
MICR_SOL2
QM8(7)
NPN
QM8(9)
NPN
Q28
PNP
Q32
PNP
INV
3 4
INV
34
INV
3 4 1 2 12
S
S
S
S
S
S
S
N
N
N
N
N
N
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
Check paper movement