Sharp Mx-b200 Service Manual

MX-B200  UNPACKING AND INSTALLATION  5 - 12 11) Attach the motor connector and the snap band to the original
position.
12) Attach the Scanner UPG mylar J3 to cover the hole on the right
side of inside of the scanner.
Note:The mylar should cover the hole shown by the arrow in
the diagram.
Attach along with the bent part of the metal plate and align the
edge of the mylar with the line shown in the diagram (the yellow
line in the diagram).
13) Attach the Fan housing cushion to the cooling fan at the posi-...

MX-B200  COPY PROCESS  6 - 1
[6] COPY PROCESS
1. Functional diagram
(Basic operation cycle)
(20 microns thick)
Aluminum drum  Pigment layer (0.2
to 0.3 microns thick) An OPC drum is used for the photoconductor.
(Structure of the OPC drum layers)
OPC layer
Main charger
Laser beam
MG rollerCleaning blade
Drum
Transfer unit
Resist roller
Exposure Main high voltage unit
Saw toothCharge
Drum
Cleaning
Cleaning blade
Waste toner box
Paper release Fus ing
Separation
Heat roller
Heater lampTransferTransfer...

MX-B200  COPY PROCESS  6 - 2
2. Outline of print process
This printer is a non-impact printer that uses a semiconductor
laser and electrostatic print process. This printer uses an OPC
(Organic Photo Conductor) for its photoconductive material.
First, voltage from the main corona unit charges the drum surface
and a latent image is formed on the drum surface using a laser
beam. This latent image forms a visible image on the drum surface
when toner is applied. The toner image is then transferred onto the...

MX-B200  COPY PROCESS  6 - 3 Step-3: Developing (DC bias)
A bias potential is applied to the MG roller in the two component
magnetic brush developing method, and the toner is charged nega-
tive through friction with the carrier.
Non-image area of the drum surface charged with negative
potential repel the toner, whereas the laser exposed portions
where no negative charges exist, attract the toner. As a result, a
visible image appears on the drum surface.
Toner is attracted over the shadowed area because...

MX-B200  COPY PROCESS  6 - 4 Step-7: Optical discharge (Semiconductor laser)
Before the drum rotation is stopped, the semiconductor laser is
radiated onto the drum to reduce the electrical resistance in the
OPC layer and eliminate residual charge, providing a uniform state
to the drum surface for the next page to be printed.
When the electrical resistance is reduced, positive charges on the
aluminum layer are moved and neutralized with negative charges
on the OPC layer.
Charge by the Scorotron charger...

MX-B200  OPERATIONAL DESCRIPTIONS  7 - 1
[7] OPERATIONAL DESCRIPTIONS
1. Outline of operation
The outline of operation is described referring to the basic configuration.
(Basic configuration)
(Outline of copy operation)
Setting conditions
1) Set copy conditions such as the copy quantity and the copy
density with the operation section, and press the Start key. The
information on copy conditions is sent to the MCU.
Image scanning
2) When the Start key is pressed, the scanner section starts scan-
ning of...

MX-B200  OPERATIONAL DESCRIPTIONS  7 - 2
2. Scanner section
A. Scanner unit
The scanner unit in the digital copier scans images.
It is composed of the optical unit and the drive unit. The optical unit
performs scanning in the main scan direction with the light receiving
elements (color CCD). The drive unit performs scanning in the sub
scanning direction by moving the optical unit.
B. Optical system
Two white lamps are used as the light source.
Light radiated from the light source is applied to the...

MX-B200  OPERATIONAL DESCRIPTIONS  7 - 3
3. Laser unit
The image data sent from the MCU (image process circuit) is sent
to the LSU (laser unit), where it is converted into laser beams.
A. Basic structure
The LSU unit is the writing section of the digital optical system.
The semiconductor laser is used as the light source, and images
are formed on the OPC drum by the polygon mirror and fθ lens, etc.
The laser beams are passed through the collimator lens, the cylin-
drical lens, the polygon mirror, the fθ...

MX-B200  OPERATIONAL DESCRIPTIONS  7 - 4
A. General description
General block diagram (cross section)
Top view
(1) Heat roller
A Teflon roller is used for the heat roller and a silicone rubber roller
is used for the lower heat roller for better toner fusing performance
and paper separation.
(2) Separator pawl
Three separator pawls are used on the upper heat roller. The sep-
arator pawls are Teflon coated to reduce friction with the roller and
prevent a smear on the paper caused by the separator pawl.
(3)...

MX-B200  OPERATIONAL DESCRIPTIONS  7 - 5
(1) Cassette paper feed operation
1) The figure below shows the positions of the pick-up roller, the
paper feed clutch sleeve, and the paper feed latch in the initial
state without pressing the Start key after lighting the ready
lamp.
The paper feed latch is in contact with the projection of the
clutch sleeve.
2) When the Start key is pressed, the main drive motor starts
rotating to drive each drive gear.
The pick-up drive gear also is driven at that time. Since,...