Toshiba e-STUDIO2330C Service Manual page 75

[B] Charging
Charging is a process to apply charge evenly to the drum surface.
The needle electrode produces negative corona discharge, which is controlled by the grid so that the
drum surface is evenly charged with negative potential.
The surface potential on the drum is determined by the grid potential and is controlled to a fixed value
by the grid control circuit.
[C] Data reading (scanning)
Data reading is a process of illuminating the original with light and converting the reflected light into
electrical signals.
The light reflected from the original is directed to the Charge Coupled Device (CCD) and this optical
image information is converted to electrical signals (image signals), which are then transmitted to the
image processing section via the scanning section control PC board.
The CCD for color processing has RGB filters provided over its surface, which allow the CCD to read
the light amount in the respective ranges of wavelength. The image data corresponding to the
respective RGB colors is then transmitted to the image processing section.
CCD board
Scanning section
control PC board
Image processing
Fig. 4-7
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Rotation of drum
Main charger
Grid control circuit
Fig. 4-6
( Example )
Light
section
Dark
4 - 5
High-voltage
transformer
CCD light Value of image
signals to be
receiving
amount output
255
Difference between
"light " and "dark" is
divided into 256 steps.
0
Fig. 4-8
e-STUDIO2330C/2820C/2830C/3520C/3530C/4520C
4
COPY PROCESS