4-9
UP-D70/D70A (UC,CE)
q) LED_ON_nOFF Circuit (CN5-18)
Function
: This circuit turns ON or OFF LED of each sensor between items (h)
→
(q).
This is performed self diagnosis of each sensor.
Level
: Usual (when LED lights ON) is H.
Check method : When performing self diagnosis, if all sensors are error, this circuit may be
damaged.
r) Bar-code sensor/luminance quantity adjustment (CN5-11, 20)
Function
: This reflection sensor reads 12bit bar-code attached to ink ribbon. Pair LED
luminance is set to obtain the most suitable luminance quantity. When
reading ribbon code every time, the threshold level value for judging L or H
is changed to the most suitable value.
Level
: Reflection portion of bar-code is L, black portion is H.
Check method : Ribbon cassette with bar-code is inserted, and make sure that ribbon error is
not indicated. (It can not be obtained by self diagnosis.) If ribbon error is
indicated, make sure the threshold level and, paper feed lever should be
moved to printing position, load motor should be rotated reversely, make sure
the sensor output.
ON/OFF control from
CPU (IC101)
Each sensor
LED
D/A converter (IC110)
A/D port (CPU IC101)
+
-
