Paper Size Detection Control - Minolta Di551 Service Manual

BY-PASS TRAY
2. Signals
a. PRCB input signals
(1) BPUP_PS (PS34 to PRCB)
Paper upper limit position detection signal (by-
pass tray)
[L]: Not detected.
[H]: Detected.
(2) BPDN_PS (PS35 to PRCB)
Paper lower limit position detection signal (by-
pass tray)
[L]: Not detected.
[H]: Detected.
b. PRCB output signal
(1) BPUDM_A, B (PRCB to M20)
M20 drive control signal

[5] Paper Size Detection Control

5V2
S.GND
DCPS
The size of paper in the by-pass tray is detected
by PS31 (paper size/1-BP), PS32 (paper size/2-
BP), and VR5 (paper size/BP). Based on the
detection signals, PRCB (printer control board)
judges the paper size.
1. Operation
The length of paper is detected by PS31 (paper
size/1-BP) and PS32 (paper size/2-BP). The by-
pass tray is provided with a variable resistor
(VR5) interlocked with the guide position to judge
the paper width according to the change in the
resistance value.
The relationships between the sensors and
paper sizes (lengths) are as follows:
Paper size
Sensor
PS31
PS32
2. Signals
a. PRCB input signals
(1) BPSIZE_S_PS (PS31 to PRCB)
Paper size detection signal
[L]: Paper does not exist.
[H]: Paper exists.
(2) BPSIZE_L_PS (PS32 to PRCB)
Paper size detection signal
[L]: Paper does not exist.
[H]: Paper exists.
(3) BPSIZE_VR (VR5 to PRCB)
Paper width detection signal
2-L-4
5V3
BPSIZE_S_PS PS31
SGND
5V3
PS32
BPSIZE_L_PS
SGND
5VA
VR5
BPSIZE_VR
PRCB
8.5 x 11 A4R to F4 or
or less B5R larger
OFF ON ON
OFF OFF ON