Detection Mechanism; Home Position Detection Mechanism - Samsung SRP-275 Service Manual

8-3 Detection mechanism

Each of the detection component mechanism in the SRP-275 and their corresponding function are listed
below. Detailed explanations of each of the detection mechanism are provided in this section.
Detection mechanism
Home position
Paper near end
Paper end
Rear cover open
Auto cutter home position
Switch-paper near end-W
Switch-paper near end
Switch-paper end
Home position sensor

8-3-1 Home position detection mechanism

The home position detection mechanism consists of the detection plate at the left side of the Carriage head
ass'y and the home position sensor at the left side of the Frame-main. It determines the home position,
identifies the head carriage position, and detects Carriage head ass'y operation errors.
The home position sensor consists of an LED and photo transistor. When the Carriage head ass'y moves,
the detection plate passes between the LED and photo transistor and blocks the optical axis of the photo
transistor, changing the output level of the photo transistor.
Rev. 2.00
Initial setting of SRP-275
Detection of presence/a little presence of paper roll
Detection of presence/absence of paper roll
Detection of the rear cover open/close
Initial setting of Auto cutter
Head carriage detection plate
LED
- 132 -
Function
Auto cutter
Home position sensor
Switch-cover rear open
+5V
Photo transistor
Detection signal
GND
SRP-275
Cover middle
Cover base