Scanner - Xerox WorkCentre Pro 412 Service Manual

Circuit Description

5-3 Scanner

5-3-1 Summary
This flat-bed type device to read manuscripts has 600dpi CCD as an image sensor. There is one optical sen-
sor for detecting CCD home position and Scan-end position. The home position is detected by a optical sen-
sor which is attached to the CCD Module. The Scan-end position is calculated by the number of motor steps.
CCD
Contact Image Sensor improves productivity and allows a compact design.
This machine uses a color CCD.
• Minimum scan line time for one color: 5mS.
• Light source power: +12V.
• Maximum pixel frequency: 6 MHz.
• Effective sensor element: 5340 X 3.
• Clamp level: 0.7 to 0.8V.
• Bright output: min. 0.8V.
AIN
AD C_REF T
ADC _REFB
[ AFE]
12-bit
A/ D c onv erter
SRAM
1 024 x 8
( R/G/ B)
SRAM
8 192 x 8
( 2l ine)
Interrupt
IRQ
Contro l
CPU I/F
Mod ule
n CS n RD n WR
5-18
R_L ED,
G _LE D,
PI_TG B _LE D
PI1 PI2
Sen so r
Interfac e
Shadi ng
C orrec tio n
Gam ma
C orrec tio n
Enlarge men t
/ Redu c tion
Vp eak
Contro l
CIP3
Regis ter
A [ 5 : 0] D [ 15 : 0] n XDREQ
DUOIP2 Block Diagram
August 2001
EXT SRAM
Shadi ng
Ac qu isitio n
Vertic al
D ec im ation
SRAM
Imag e
256 x 8
Proc es s ing
Mo dule
SRAM
4 09 6 x16
(2 line )
Mo to r
Con tro l
D MA
Interfac e
SRAM
1 024 x 8
n XDACK
SRAM_A[ 15:0]
SRAM_D[ 15: 0]
SRAM_nRD
SRAM_nWR
TX_A, B
n TX_A, B
TX_EN1, EN2
WorkCentre Pro 412
Launch Issue