Print Head Up/Down Detection Mechanism - Citizen CLP-621 Technical Manual

2-1-5. Print Head Up/Down Detection Mechanism

The component of the print head up/down detection mechanism is as follows:
(a) Head up sensor
(b) Protrusion that engages in the sensor
The print head up/down detection mechanism detects the up (open)/down (close) status of the
head block.
When the head block is in the up position, the protrusion "A" is disengaged from the head up
sensor. At this time, the head up sensor turns ON and "Low" level is output from the head up
sensor.
While, the head block is in the down position, the protrusion "A" is engaged in the head up sensor.
At this time, the head up sensor turns OFF and "High" level is output from the head up sensor.
The CPU on the Main PCB detects up or down position of the head block by sensing the output of
the head up sensor.
Head Block
Head Up Sensor
(SA, Head Up Sensor PCB)
Head Block "Up" position
A
A
SA, Head Up Sensor PCB
Head Block "Down" position
A
SA, Head Up Sensor PCB
2-13
2-1. Operation of Each Mechanism
Photo
Interrupter
Photo
Interrupter
CLP-621 & CLP-631