Service manual

AR-M351U/M451U, AR-M355U/M455U MAINTENANCE AND DETAILS OF EACH SECTION 7 - 48
C. Operational descriptions
(1) CCD/lens unit
This machine employs the reduction optical-type line CCD (Charge Coupled Device) of scan resolution of 600dpi and 7450 pixels.
CCD scan is performed by shifting the scan positions sequentially by the carriage unit (lamp and mirror) scan or moving the document with
the SPF.
Lights reflected by the document are reflected by each mirror to form images on CCD elements through the reduction-type lens. The CCD
converts the optical energy into electrical energy (analog). (Photoelectric conversion)
(2) CIS unit
The image sensor which scans back document images is attached to the SPF. The close-contact type image sensor (Contact Image Sen-
sor) with scan resolution of 600dpi and 7196 pixels is employed.
For the CIS to scan documents, the scan position is sequentially shifted by shifting the document by the SPF, and the LED light in the unit
is radiated to the back of the document, and photo energy is converted into electric energy (analog signal).
No. Name Function
1 Copy lamp unit Lights up to radiate documents. A xenon lamp (operating on 3.15KV) is employed.
2 Reflector This mirror converges lights on documents.
3 No. 1 mirror Secures the optical path between a document and No. 2 mirror.
4 No. 2 mirror Secures the optical path between No. 1 mirror and No. 3 mirror.
5 No. 3 mirror Secures the optical path between No. 2 mirror and the CCD.
6 CCD/Lens unit The reduction optical type CCD (Charge Coupled Device) of 7,450 pixels is employed. The scan resolution
is 600dpi. Converts photo energy reflected by the mirrors into electric energy.
7 White balance sheet Serves as the reference sheet of white for scanning with the CCD/Lens unit. If dust or dirt is attached to
this sheet, white streaks may be produced.
8 Table glass A document is set on this glass. The glass surface is coated for protection against static electricity.
A document is set to the top left corner.
9 SPF scan glass The copy lamp unit is fixed, and a document is moved over this glass to scan line by line. The glass
surface is coated for protection against static electricity. If dust or dirt is attached to this sheet, black
streaks may be produced.
10 Mirror home position
sensor (MHPS)
Detects the home position of the mirror base unit.
11 Scan motor Drives the mirror base and the copy lamp unit.
12 DSPF white balance
sheet
Serves as the reference sheet of white for scanning with the CIS unit.
If dust or dirt is attached to this sheet, white streaks may be produced.
Lens center line
Focus point
LED PWB
CIS
CIS UNI
Auto-focus lens
Glass