2 - E - 12
READ SECTION
[6] Original Read Control
425-A1 481-A1
CB
420-40
IPB
ADB
411-1
420-1 411-40
CCD
425-A12 481-A12
425-B1 481-B1
425-B12 481-B12
The original is read by the ADB (A/D converter board) and the
CCD sensor installed on the ADB.
1. Operation
The light reflected off the exposed original passes through a
lens to the CCD sensor. The analog voltages that correspond
to the input light intensity are A/D-converted in the ADB, and
output to the IPB (image processing board).
a. Original read operation
The original read timing is as follows.
(1) During a platen copy operation
When PS4 (paper feed restart) goes ON.
(2) During an ADF copy operation
When the exposure unit is +2 mm toward the paper
feed side from the position at which PS4 goes ON.
[7] APS Control
APS takes place as a result of the signal read by the APS
sensor being sent to the CB (control board) when the original
cover is opened and closed.
Related signals are PS45 (APS timing 1) and PS44 (book
detection).
1. Operation
a. APS detection operation
APS detection is an operation that detects the paper size
according to the particular ON/OFF combination of (APS
(long)), PS42 (APS (inner)).
The APS sensor consists of LEDs and photosensors. APS
detection takes place as a result of the light emitted from
each LED being reflected off the original and received by
the photosensor.
The relation between each sensor and the paper size is
shown below.
5VDC
PS6
PS44
PS45
5VDC
PS40
PS41
PS42
9-B8
9-B4
9-B5
9-B7
22-A5
22-A6
22-A8
22-B1
CB
143-3
143-2
PS44
137-3
137-2
PS45
134-3
134-2
PS41
130-3
130-2
PS42
PS42
PS41
LED
Paper exit side
Photosensor
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