Seiko Instruments LTP F Series - Manual (Page 47)

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3.7 PAPER DETECTOR
The printer has a built-in paper detector (reflection type photo-interrupter) to detect whether paper is
present or not.
An external circuit should be designed so that it detects the output from the paper detector and does
not activate the thermal head when there is no paper. Doing not so may cause damage to the thermal
head or platen roller or shorten the life of the thermal head significantly.
3.7.1 General Specifications
Table 3-13 Absolute Maximum Ratings of the Paper Detector (at 25 °C)
Item Symbol Maximum Rating
Forward current I
F
50 mA
Reverse voltage V
R
5 V
LED (input)
Allowable current P 75 mW
Collector-to-emitter voltage V
CEO
20 V
Emitter-to-collector voltage V
ECO
5 V
Collector current I
C
20 mA
Photoransistor
(output)
Collector loss P
C
70 mW
Operating temperature T
opr
-20 to +80 °C
Storage temperature T
stg
-30 to +100 °C