MX-1800N (serv.man23). Details of each Section - C Scanner Section. - Sharp Copying Equipment Service Manual (repair manual). Page 2

MX-1800N  SCANNER SECTION  C – 2

This section functions and operates as follows:
1) The copy lamp radiates light onto the document, and the

reflected light is scanned by the three line (RGB) CCD element
and then converted into image signals (analog).

2) The image signals (analog) are converted into 10bit digital sig-

nals by the A/D converter.

3) The image signals (digital) are sent to the image process sec-

tion (scanner control PWB).

The optical section drive power is transmitted from the scanner
motor (MIM) through the belt, the drive pulley, and the wire to drive
the copy lamp unit and the mirror base which are attached by the
drive wires.
The scanner motor (MIM) is controlled by the drive signal sent from
the scanner control PWB.

The scanner lamp (CLI) is driven by the scanner lamp drive voltage
generated in the CL inverter PWB according to the control signal
sent from the scanner control PWB.

Light is radiated to a document by the scanner lamp, and the
brightness of the reflected light is received by the three line (RGB)
CCD element and converted into (analog) image signals.
Each color component of RGB is separately extracted from the
document image by the three lines (RGB) of the CCD elements.
The red CCD extracts the red components from the document
image, the green CCD the green components, and the blue CCD
the blue components. This operation is called Color Separation.
The CCD element, appeared as one unit, but has three separate
rows of CCD elements drive each for (RGB).
Scanning of a document in the main scanning direction is per-
formed by the CCD elements. Scanning of a document in the sub
scanning direction is performed by shifting the scanner unit position
with the scanner motor.
Document images are optically reduced by the lens and projected
to the CCD elements.
Scanning resolution is 600 dpi.

(Image data per 1 line)

1)

Each image signal (analog) of RGB is converted into 10bit dig-
ital signal by the A/D converter.
Each color pixel has 10bit information (256 gradations).

2)

Each 10bit digital image signal of RGB is sent to the image
process section. 

Zooming in the sub scanning direction is performed by changing
the scanning speed in the sub scanning direction.
Zooming in the main scanning direction is not performed optically
but by the image process technology (software).

R

G

B

Red component of
image data

Blue component of
image data

Green component of
image data

R

G

B

CCD PWB

Transfer IC

B ADC

B

B

3

CCD

B

IC

G

IC

R

IC

G ADC

R ADC

R

R

G

G