SCANNER UNIT
24 February, 1999
2-28
2.4.5 WHITE PLATE SCANNING
There is a white plate [A] for auto shading, stuck on the exposure glass [B]
underneath the left scale. When this white plate is scanned, the output from all the
CCD elements in a line should in theory be equal, but actually it is not, for the
following reasons:
•
Variations in sensitivity between elements of the CCD
•
Variations in characteristics of lens and mirror reflectivity
•
Loss of brightness toward the ends of the exposure lamp
To correct for this uneven output from the CCD elements, the light reflected from
the white reference plate is scanned. This is known as auto shading.
Auto shading is done every copy cycle at the scanner home position before starting
the first scan.
2.4.6 SCANNER IPU BOARD
The scanner IPU board processes the RGB signal received from the CCD board
and controls the following under the control of the main control board.
1. Controls exposure lamp on/off switching and voltage
2. Controls the speed of the scanner drive motor
3. Detects the original paper size
4. Controls on/off switching for the scanner exhaust and optics cooling fans
5. Supplies the clock signals for the CCD board
6. Detects when the scanner is at home position
A259D801.WMF
[A]
[B]
Summary of Contents for Aficio Color 4006
Page 230: ...SP MODE TABLE 24 February 1999 4 2 4 3 SP MODE TABLE See Appendix 2 ...
Page 359: ...SC TABLE 24 February 1999 7 2 7 2 SC TABLE See APPENDIX 3 ...
Page 364: ...APPENDIX 1 TIMING CHARTS ...
Page 369: ...APPENDIX 2 SP MODE TABLE ...
Page 436: ...APPENDIX 3 SC CODE TABLE ...
Page 467: ...APPENDIX 4 RSS Remote service system ...
Page 479: ...7 A259S101 WMF 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 Fig 1 ...
Page 480: ...8 A259S102 WMF 1 2 3 4 5 6 7 8 10 11 12 13 14 9 Fig 2 ...
Page 481: ...9 A259S103 WMF 1 2 3 4 5 7 8 9 10 11 12 14 15 13 6 16 Fig 3 ...
Page 482: ...10 A259S151 WMF 1 2 3 4 5 7 8 10 9 6 11 12 13 14 16 17 18 19 15 Fig 4 ...
Page 483: ...11 A259S105 WMF 1 2 3 4 5 6 7 8 9 10 Fig 5 ...
Page 484: ...12 A259S106 WMF 1 2 3 4 6 7 8 9 5 Fig 6 ...
Page 485: ...13 A259S107 WMF 1 2 3 4 5 6 7 8 10 11 9 Fig 7 12 ...
