Sharp UX-P200 Service Manual page 34

UX-P100U
UX-P200U
Paper feed plate
Separate
rubber
Separate
plate
3-5. Documents requiring use of document carrier
1) Documents smaller than 148mm (W) x 140mm (L).
2) Documents thinner than the thickness of 0.06mm.
3) Documents containing creases, folds, or curls, especially those whose
surface is curled (maximum allowable curl is 5mm).
4) Documents containing tears.
5) Carbon-backed documents. (Insert a white sheet of paper between
the carbon back and the document carrier to avoid transfer of carbon
to the carrier.)
6) Documents containing an easily separable writing material (e.g., those
written with a lead pencil).
7) Transparent documents.
8) Folded or glued documents.
Document in document carrier should be inserted manually into the
feeder.
4. Document release
4-1. General
To correct a jammed document or to clean the document running sur-
face, pull the insertion side of document center of the operation panel.
To open the upper document guide, the operation panel must be opened
first.
5. Recording block
5-1. Driving
In the drive mechanism, the rotating force of the pulse motor for both
transmission and reception is transmitted to the paper supply roller, the
recording paper feed roller and imaging film drive gear through the pulse
motor axle gear, reduction gear and planetary gear.
5-2. Recording
This equipment employs the thermal transcription system which uses
the thermal head imaging film.
1) Thermal head
The thermal head is composed of 2,016 heating elements in traverse
line, and the resolution power is 8 dots/mm. The maximum speed is 10
ms/line.
Back of
document
Last page of
document
First page of
document
Paper feed roller
Fig. 4
2) Structure of recording mechanism
Recording is achieved by applying a suitable pressure to the thermal
head through the imaging film of the recording paper feed roller and the
recording paper.
The main scanning is electronically performed, and the sub-scanning is
mechanically performed (by sending the recording paper with the re-
cording paper feed roller).
3) Recording paper transfer sequence
a) The recording paper stored in the paper tray ass'y is fed with the PU
roller, and is stopped when the P-IN sensor is turned on by sensing
its lead edge.
b) Hereafter, the imaging film and recording paper are transferred with
the recording paper feed roller, and thermal transcription is performed
on the recording paper.
c) After thermal transcription, the imaging film is taken up by the roller
on the take-up side, and the recording paper is discharged by the
back roller.
Troubleshooting the density unevenness mainly results from the
longitu-dinal misalignment of the thermal head to the heater line. Oth-
erwise, the head is in uneven contact with the recording paper feed
roller, or the imaging film is wrinkled.
1 The following items are described as the simplified checking method.
Are the power and signal cables of the thermal head suitably treated?
2
Does the same symptom appear even if the thermal head pressure
spring is replaced?
3
Is the feed roller of the recording paper concentric? (Density is un-
even at intervals.)
4
Does the same symptom appear even if the thermal head is replaced?
5
Is the imaging film stained or wrinkled?
5-3. General view
Separate rubber
P-IN sensor lever
(Upper)
Platen roller
Release lever
Imaging film
(Take-up side)
3 – 2
Paper
Feed plate
tray ass'y
(Accessory)
PU roller
Imaging film
(Supply side)
Thermal head
Film sensor lever
Fig. 5
Paper
tray
extension
(Accessory)