Toshiba e-studio550 Service Manual page 47

(3) Scanning
Scanning is a process of exposing the original to
the light and converting the reflection into electrical
signals.
The light reflected from the original is imported to
the charge coupled device (CCD) and this optical
image information is converted into electrical sig-
nals (image signals), which are then sent to the
image processing section.
(4) Writing
Writing is a process of converting the image signals
sent from the image processing section into optical
signals and exposing the drum surface to the light.
Semiconductor laser element converts image sig-
nals sent from the image processing section into
optical signals (laser emission) and exposes the
drum surface to the light to form an electrostatic
latent image on it.
JUNE 2002 © TOSHIBA TEC
(Example)
CCD light
receiving
amount
Light
Dark
Image
processing
section
Polygonal mirror
Photo-
conductive
drum
3 - 3 e-STUDIO550/650/810 COPY PROCESS
CCD
Image processing
section
Value of
image signals
to be output
255
Difference between
"light " and "dark" is
divided into 256
steps.
0
Laser Drive
board
Semiconductor
laser element