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3-3. Sensor
(1) Paper-Out Sensor
The paper-out sensor is located at the paper entry slit. The detector consists of a reflective photosensor. The
photosensor’s phototransistor remains ON while paper is present. It goes OFF when paper runs out, generating output
of a paper-out signal.
(2) Black-Mark Sensor
This detector senses black marks indicating print start positions. The detector is useful only with specially marked
paper. Like the paper-out detector, the black-mark detector consists of a reflective photosensor. The photosensor’s
phototransistor goes OFF when a black mark appears.
Fig. 2-15 Paper-Out Detector Fig. 2-16 Black-Mark Detector
(3) Paper Near-end Sensor
The Paper Near-end Sensor detects the amount of paper remaining on the roll. When the roll paper no longer exists
at the set position, the reflective photosensor turns OFF and outputs a no paper signal.
Fig. 2-17 Paper Near-end Sensor
GND
+5V
R
R
GND
+5V
R
R
Paper
(Reflective Photosensor)
Detection Signal
Paper
Black Mark
(Reflective Photosensor)
Detection Signal
GND
+5V
R
R
Paper
(Reflective Photosensor)
Detection Signal