Epson TM-U950 Technical Manual page 93

CONFIDENTIAL
Slip paper insert sensor circuit
The slip paper insert sensor signal is output to CPU analog port via pull-down resistance and
integral circuit. Slip paper existence is judged by comparison between the threshold value in
U20 and the detected value. (For the threshold value, see Adjustment in Chapter 5.)
Slip paper eject sensor circuit
Slip paper eject detection is performed using a reflecting photosensor. To prevent errors due to
external light, 2-kHz frequency modulation is used. The SO_K signal (light source drive) is
turned on and off by the CPU in a 2-kHz cycle. The SO_E signal (light source detection) passes a
2-kHz filter and amplifier. The CPU then reads the level of this signal (CSOE) via an analog port
to determine the presence or absence of paper.
2-48 Mechanism Configuration and Operating Principles
Figure 2-61. Slip Paper Insert Sensor Circuit
Figure 2-62. Slip Paper Eject Sensor Circuit
Rev. A