Sharp AL-1661CS, Service Manual

Page: 38 / 216

AL-1661CS OPERATIONAL DESCRIPTIONS 7 - 2
2. Scanner section
A. Scanner unit
The scanner unit in the digital copier scans images.
It is composed of the optical unit and the drive unit. The optical unit
performs scanning in the main scan direction with the light receiving
elements (color CCD). The drive unit performs scanning in the sub
scanning direction by moving the optical unit.
B. Optical system
Two white lamps are used as the light source.
Light radiated from the light source is applied to the document on the
document table. The reflected light from the document is reflected 5
times by No. 1 - No. 3 mirrors and passed through the reduction lens to
form images on the light-receiving surface of 3-line CCD.
The light-receiving surface of the color CCD is provided with 3 line
scanning sections for RGB. Separate images scanned in each color
section are overlapped to complete color scanning. (When PC scan-
ning)
The resolution is 600dpi.
When copying, only the green component is used to print with the
printer.
The color component for printing can be switched to red or blue by the
service test command.
(Spectrum characteristics of the lamp)
(Spectrum characteristics of the color CCD)
(Optical unit)
C. Drive system
The drive system is composed of the scanner motor, the pulley gear,
the idle pulley, the idle gear, the belt 473, the belt 190, and the shaft.
The motor rotation is converted into reciprocated movements of the
belt 473 through the idle gear, the pulley gear, the belt 190, and the
idle pulley to drive the optical unit.
MBVM26W25W260NLH/G
0.00E+00
1.00E-01
2.00E-01
3.00E-01
4.00E-01
5.00E-01
6.00E-01
0 200 400 600 800
Wave length (nm)
Intensity of UV
Lamp : MBVM26W25W260NLH/G
Lamp current : 5mA
Temp. : 25 degree
1 Table glass 2 Optical unit 3 Lens
4 Mirror 1 5 Mirror 2 6 Mirror 3
7 CCD PWB 8 Lamp 9 Reflector
1
9
8
10
8
9
7
3
5
4
2
6
1 Scanner motor 2 Pulley gear 3 Idle pulley
4 Belt 473 5 Belt 190 6 Optical unit
7 Shaft 8 Idle gear 9
7
3 4 6 2 8 5
1
3