Detection Mechanism Unit
The detection mechanism unit consists of the home position detection, paper detection, and
near-end detection (optional) mechanisms.
Home position detection mechanism
The home position detection mechanism consists of the detection protrusion at the left side of the
carriage sub assembly and the sensor sub assembly at the left side of the base frame. It determines the
home position, identifies the carriage position, and detects carriage sub assembly operation errors.
The sensor sub assembly consists of an LED and photo transistor. When the carriage sub assembly
moves, the detection protrusion passes between the LED and photo transistor and blocks the optical
axis of the photo transistor, changing the output level of the photo transistor.
The change in the output level is used as a signal to detect the movement of the carriage sub assembly.
Figure 2-11 Detection mechanism unit
Figure 2-12 Home position detection diagram
Paper detector
Home position sensor
Printer side
The light is blocked
The light is
not blocked
Carriage sub assembly detection protrusion
Signal level at A
High
Low
+5V
GND
A
— 34 —
Summary of Contents for UP-250
Page 1: ...EXTERNAL PRINTER FEB 2000 MODEL UP 250 without price TECHNICAL MANUAL ...
Page 95: ... 86 END END Yes No Action 4 Replace main PCB Replace printer OK Action 4 mechanism assembly ...
Page 136: ... 127 ...
Page 149: ... 140 Main Circuit Board Parts Layout ...
Page 150: ... 141 RS 232 Serial Interface Circuit Board Parts Layout ...
Page 151: ... 142 IEEE 1284 Parallel Interface Circuit Board Parts Layout ...
Page 152: ...RS 485 Serial Interface Circuit Board Parts Layout 143 ...
Page 160: ... 151 Case Unit Lubrication Points Diagram 4 G 31 4 G 31 3 G 31 3 G 31 ...
Page 163: ... 154 EXPLODED DIAGRAM FOR TM U200B U210B NO 1 ...
Page 164: ... 155 EXPLODED DIAGRAM FOR TM U200B U200PB U210B U210PB NO 2 ...