Read Sharp AL-1622 (serv.man20) Service Manual online
AL-1611/AL-1622
OPERATIONAL DESCRIPTIONS
6 – 1
[ 6 ] OPERATIONAL DESCRIPTIONS
1. OUTLINE OF OPERATION
The outline of operation is described referring to the basic configuration.
(Basic configuration)
Outline of copy operation
A. Setting conditions: Operation panel
• Set copy conditions such as the copy quantity and the copy density
with the operation section, and press the START key. The informa-
tion on copy conditions is sent to the MCU.
tion on copy conditions is sent to the MCU.
B. Image scanning: Scanner section
• When the START key is pressed, the scanner section starts scanning
of images. The light from the copy lamp is reflected by the document
and passed through the lens to the CCD.
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 synchroni-
zation with the image lead edge.
• The toner image is transferred on the paper.
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 sequen-
scan a certain area of a document at a time and deliver outputs sequen-
tially. When the line is finished, the next line is scanned, and this proce-
dure is repeated. The figure below shows the case where an image
which is scanned is shown with solid lines.
which is scanned is shown with solid lines.
The direction of this line is called main scanning direction, and the scan-
ning direction sub scanning direction. In the figure above, one line is
divided into 5 sections. Actually, however, one line is divided into thou-
sands of sections. For scanning, the light receiving element called CCD
sands of sections. For scanning, the light receiving element called CCD
is used.
The basic resolution indicates the scanner capacity. The basic resolu-
tion is expressed in dpi (dot/inch) which shows the number of light emit-
ting elements per inch on the document.
ting 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.
tion.
Operation
section
Scanner section
CCD
MCU (Main control/image process section)
Laser beam
Paper exit
Fusing
section
section
Paper t
ransport
section
ransport
section
Manual paper
feed section
Cassette paper
feed section
Printer section
LSU (Laser unit)
Laser diode, Polygon mirror lens
Laser diode, Polygon mirror lens
Process section
1
2
3
4
5
5
4
3
2
1
Sub scanning direction
Sensor scanning area
Main
scanning
direction
scanning
direction
To MCU PWB
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