Sensors; Head Up Sensor (Sa Head Up Sensor Pcb) - Citizen CL-E700 series Technical Manual

2-2-4. Sensors

(1) Head up sensor (SA Head Up Sensor PCB)

The head up sensor is used to detect the head position (up or down). This sensor uses a
photointerrupter.)
When the head block is closed (in the down position), the projection "A" of the head block is
engaged in the head up sensor, and the light emitted from the LED of the photointerrupter is
blocked by the projection "A". Thus, the phototransistor turns OFF, and pin 24 (HDUSENS) of
the CPU (U1A) goes to "High" level.
When the head block is opened (in the up position), the projection "A" is disengaged from the
head up sensor, and the light emitted from the LED reaches the phototransistor. Thus, the
phototransistor turns ON and pin 24 (HDUSENS) of the CPU goes to "Low" level.
When the head block is opened, the LED on the operation panel blinks in red and the LCD
displays "Error Head Open". Then, the printer goes off-line.
U1A
CPU
24
P6_4
L: Head Up
H: Head Down
+3.3V
R104
R106
HDUSENS
C133
Head Block
SA Head Up Sensor PCB
(Head Up Sensor)
+3.3V
J10
CN201
R105
1 1
2 2
3 3
[SA Head Up Sensor PCB]
[SA Main PCB]
Head Block "Up" position
A
SA Head Up Sensor PCB
Head Block "Down" position
SA Head Up Sensor PCB
2-23
Chapter 2 Operating Principles
2-2.
Operation of Control Parts
Head Up Sensor
Photo-
A
Interrupter
Photo-
A
Interrupter
CL-E700 series