Transparent Sensor And Reflective Sensor - Citizen CL-S6621 Technical Manual

Operation of Control Parts

(2) Transparent sensor and reflective sensor

The transparent sensor ("SA TRA Sen PCB") is used to detect the label stuck on liner and the
U-shaped notch on tag. On the other hand, the reflective sensor ("SA Ref Sen PCB") is used to
detect the black mark printed on the bottom surface of tag. Both sensors are also used to
detect the media end.
The upper side transparent sensor is the phototransistor, and the lower side reflective sensor
consists of 2 LEDs and 1 phototransistor. Media passes between these sensors.
U1A
CPU
ANI0
Transparent sensor
output sensing terminal
Reflective sensor output
sensing terminal
ANI1
U14
FPGA
R14
B4_34
R13
B4_33
From
U1A CPU
Transparent sensor (used for detecting the label or U-shaped notch):
When the liner without label stuck on it passes between both sensors, the light emitted from
the LEDs reaches the transparent sensor, passing through the liner. Thus, the transparent
sensor (phototransistor) conducts and the voltage corresponding to the amount of light is
applied to pin 5 (TRAMON) of U1A (CPU).
Meanwhile, when the liner with the label stuck on it passes between both sensors, the light is
blocked by the label and the transparent sensor (phototransistor) turns OFF. Thus, pin 5
(TRAMON) of U1A (CPU) goes "Low" level. From the difference in these levels at pin 5
(TRAMON) of U1A (CPU), U1A (CPU) can detect the leading edge (arrival) of the label on the
liner.
When media runs out, the light directly falls on the transparent sensor and media end is
detected. In this case, pin 5 of U1A (CPU) will go "High" level.
CL-S6621
R65
U20B
+
TRAMON
7
5
-
C96
BA2904
R72
U20A
+
REFMON
1
6 -
C97
BA2904
Q9
DTC114EM
TSNSCTL1
TSNSCTL0
DTC114EM
U7
D/A Converter
12
AO1
DI
PSNSLED
11 AO2
CK
2
AO3
10
CSB
AO4
BH2227
R66
5
6
R70
R73
3
2
R74
R75
Q10
R68
Q7
DTC114EM R69
Q8
DTC114EM
R67
2-24
+3.3V
J9
Transparent Sensor
(White)
[SA TRA Sen PCB]
1
2
3
J8
(White)
1
R76
+5V
2
3
4
5 4
[SA Ref Sen PCB]
Reflective Sensor
Q6
2SC5658
R71
[SA, Main PCB]
Media