Paper detection mechanism
The paper detection mechanism is located in the paper path. The mechanism provides paper end
detection for the paper roll and semi-automatic loading by detecting presence or absence of the paper
roll when it is inserted. Since the paper detector switch sub assembly is a micro switch, it is always ON
when the paper roll is loaded.
Paper roll near-end detection mechanism (optional)
The near-end detector assembly consists of the near-end detector lever and a microswitch sensor and
is located on the right side of the lower case. This detector senses the amount of paper left on the paper
roll.
The tip of the near-end detection lever is always pressed against the edge of the paper roll by a spring
inside the microswitch. Therefore, when there is a large amount of paper remaining on the roll, the near-
end detection lever is pressed against the side of the paper roll as depicted by the solid lines in the figure
below. This keeps the microswitch turned on. When the amount of paper left on the roll decreases below
a predetermined amount, the tip of the near-end detection lever no longer presses against the side of the
roll and moves in the direction indicated by the arrow into the hole in the center of the roll core.
This turns the microswitch off and generates a signal indicating that the paper roll is near its end.
Auto-cutter mechanism
The printer executes a partial cut (one point left uncut) by driving the cutter motor.
When the motor is energized from the standby state, the wormwheel rotates in the direction indicated
by arrow A through the gears from the motor. The resulting motion of the wheel pin through arm slot C
causes the arm to move in direction B. This, in turn, causes slot D to move the
Figure 2-13 Paper roll near-end detection mechanism
Paper roll center
Lower case
Microswitch
Near-end
detection lever
Paper roll
— 35 —
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 ...