CHAPTER 2. BASIC OPERATION
2–28
D. Media Sensor
1. Outline
The printer is provided with a media sensor to detect the width and skew of the paper, the
internal temperature, and to enable automatic head adjustment. The media sensor is located on
the carriage unit and composed of a red and a blue LED and one reflective photo sensor. When
automatically adjusting the head, to detect the cyan line pattern, the red LED is lit, and to detect
the black, magenta and yellow line patterns, the blue LED is lit.
2. Paper width detection
When paper is picked up, the blue LED in the media sensor are switched on, and if the re-
flected light level is insufficient, the red LED also is switched on. The carriage is moved while
lighting the proper LEDs (blue, red or both) and the right edge of the paper is detected when the
carriage advances and the left edge when returning. The output pulses from the linear encoder
are counted from when the carriage leaves the home position until the paper edges are detected,
and the paper width is determined from the difference between the counted values at the time of
advancing and returning.
When the paper width is less than 250.0mm, an error code is displayed on the operation panel.
If the right or left edge of the paper is detected as out of the reference position by more than
5mm, an error code (E00162) is indicated.
Media sensor
Carrriage controller
Engine controller
LED
lighting
circuit (red)
LED
lighting
circuit (blue)
+24V
Red
Blue
TH1
AMP
D/A-C
C P U
REGLEDR
REGLEDB
LEDR
LEDB
POUT
THERME
THERM_IN
J504
-1
J508
-10
J508
- 9
J508
- 7
J214
-31
J214
-32
J214
-
J214
-37
J504
-7
J504
-6
Figure 2-205
Summary of Contents for BJ-W3000
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