Outline - Sharp AL-1600 Service Manual

[6] OPERATIONAL DESCRIPTIONS
1. Outline of operation
The outline of operation is described referring to the basic configura-
tion.
(Basic configuration)
Scanner section
Operation
section
MCU (Main control/image process section)
LSU (Laser unit)
Laser diode, Polygon mirror lens
Laser beam
Process section
Printer section
Cassette paper
feed section
Outline of copy operation
A. Setting conditions: Operation panel
•
Set copy conditions such as the copy quantity and the copy den-
sity with the operation section, and press the START key. The
information on copy conditions is sent to the MCU.
B. Image scanning: Scanner section
•
When the START key is pressed, the scanner section starts scan-
ning of images.The light from the copy lamp is reflected by the
document and passed through the lens to the CCD.
C. Photo signal/Electric signal conversion:
Scanner section
•
The image is converted into electrical signals by the CCD circuit
and passed to the MCU.
D. Image process: MCU
•
The document image signal sent from the CCD circuit is processed
under the revised conditions and sent to the LSU (laser unit) as
print data.
E. Electric signal/Photo signal (laser beam)
conversion: LSU
•
The LSU emits laser beams according to the print data. (Electrical
signals are converted into photo signals.)
•
The laser beams are radiated through the polygon mirror and
various lenses to the OPC drum.
F. Printing: Process section
•
Electrostatic latent images are formed on the OPC drum according
to the laser beams, and the latent images are developed to be
visible images (toner images).
•
Meanwhile the paper is fed to the image transfer section in
synchronization with the image lead edge.
•
The toner image is transferred on the paper.
CCD
Paper exit
Fusing section
Paper transport section
Manual paper
feed section
G. Fusing: Fusing section
•
Heat and a pressure are applied to the toner image on the copy
paper to fuse the image on the paper.
2. Scanner section
A. Scan process
The scanner has sensors that are arranged in a line. These sensors
scan a certain area of a document at a time and deliver outputs
sequentially. When the line is finished, the next line is scanned, and
this procedure is repeated. The figure below shows the case where
an image which is scanned is shown with solid lines.
The direction of this line is called main scanning direction, and the
scanning direction sub scanning direction. In the figure above, one
line is divided into 5 sections. Actually, however, one line is divided
into thousands of sections. For scanning, the light receiving element
called CCD is used.
Sub scanning direction
Main
scanning
direction
5 4 3
The basic resolution indicates the scanner capacity. The basic resolu-
tion is expressed in dpi (dot/inch) which shows the number of light
emitting elements per inch on the document.
The basic resolution of this machine is 400dpi.
In the sub scanning direction, at the same time, the motor that drives
the optical system is controlled to scan the image at the basic resolu-
tion.
6 – 1
AL-1610
Sensor scanning area
1
2
3
4
5
2 1
To MCU PWB