Sharp UX-B800A, Service Manual, Page: 56 / 140

UX-B800A
3 – 1
UX-B800A
Service Manual
CHAPTER 3.
MECHANISM BLOCKS
[1] General description
1. Document feed block and diagram
2. Document feed operation
1) The original, which is set in the document hopper, feeds automati-
cally when the Front sensor is activated. This in turn activates the
drive motor which drives the paper feed roller. The document stops
when the lead edge is detected by the Original sensor.
2) The lead edge of the original is fed a specified number of pulses
after the lead edge of the document is detected for the reading pro-
cess to begin.
3) The trailing edge of the original is fed a specific number of pulses
after the trailing edge of the document deactivates the Original sen-
sor. The read process then stops and the original is discharged.
4) When the Front sensor is in the OFF state (any document is not set
up in the hopper guide), the drive will be stopped when the docu-
ment is discharged.
3. Hopper mechanism
3.1. General view
The hopper section contains document guides that are used to adjust
the hopper to the width of the original document. This ensures that the
original feeds straight into the fax machine for scanning.
Document width: 70 mm to 216 mm (70 mm size to Letter longitudinal
size)
NOTE: Adjust the document guide after setting up the document.
3.2. Automatic document feed
1) Use of the paper feed roller and separate plate ensures error-free
transport and separation of documents. The paper feed spring
presses the document to the paper feed roller to assure smooth
feeding of the document.
2) Document separation method: Separate plate
3.3. Documents applicable for automatic feed
NOTE: Double-side coated documents and documents on facsimile
recording paper should be inserted manually. The document
feed quantity may be changed according to the document
thickness.
Documents corresponding to a paper weight heavier than 70 kg (80 g/
m
2
) and lighter than 135 kg (157 g/m
2
) are acceptable for manual
feed. Documents heavier than 135 kg (157 g/m
2
) in terms of the paper
weight must be duplicated on a copier to make it operative in the fac-
simile.
3.4. Loading the documents
1. Make sure that the documents are of suitable size and thickness,
and free from creases, folds, curls, wet glue, wet ink, clips, staples
and pins.
2. Place documents face down in the hopper.
i) Adjust the document guides to the document size.
ii) Align the top edge of documents and gently place them into the
hopper. The first page under the stack will be taken up by the
feed roller to get ready for transmission.
NOTE: 1) Curled edge of documents, if any, must be straightened
out.
2) Do not load the documents of different sizes and/or thick-
nesses together.
Fig. 1
Fig. 2
Pinch roller
Paper feed roller
Exit roller
CIS unit
Back roller
Original sensor
Front sensor
Document guide upper
Document
Document cover
open
Fig. 3
10 sheets 1 sheet (Manual)
Paper weight 20 lbs.
(74.3 g/m
2)
at the environment
23
±
5
°
C
55
±
10%
14 lbs. ~ 42 lbs.
(52 g/m
2
~ 157g/m
2
)
Paper thickness (ref.) 0.09 mm 0.06 mm ~ 0.18mm
Paper size A4 (210 mm x 297 mm)
Feeder capacity A4: 10 sheets max.
Fig. 4
Document guide lower
Paper feed roller
Paper feed plate
Separate rubber
Separate plate
Sub feed plate
Document guide upper
Document
Document guide lower
Paper feed roller
Paper feed plate
Last page of document
Back of document
Separate rubber
Separate plate
Sub feed plate
Document guide upper
Document
First page of document