Multiple Feed Detection - Hitachi HT-4139-48 Instruction Manual

5.2.2 Multi-Feed Detection
(1) Transmitted Light Detection type
Detect thickness by intensity of transmitted light.
Detectable paper thickness is 41g/m
Detection type is specified by the parameter setting of the TWAIN driver. Refer to the
TWAIN driver manuals.
Feeding direction
20
To avoid mis-detection due to contamination of the detector "PC22", conduct the daily
cleaning before operation.
5-8
2
～174g/m
L0
L1
L
L0
10
2
.
①Detection position
・20～30mm from left edge of sheet
②Detection area
・Area L1excluding L0
（L0is about 25% of sheet length L）
③Judgement
・Compare light intensity between specified
thickness and measurement result of L1 area.
※As this type checks intensity of transmitted
light, prints on the paper may affect
performance.