Perfection 4870 Photo
Revision A
OPERATING PRINCIPLES
Control Circuit
28
2.4.2 Image processing operation
The sequence of scanned image processing is explained in order below.
1. CCD Board (CCD Image Sensor)
Optoelectronic transformation processing (reflected light (optical energy)
from a document surface is transformed into electric charge (electric energy))
Amplification processing
2. Main Board (Scanned image data processing)
A/D conversion processing (scanned image data generated as an analog
electric signal is converted to a digital signal)
Shading correction processing (scanned image data is corrected on the basis
of the white and black reference values)
Various image correction processing (gamma correction, color correction,
halftone correction, etc. are executed under the set conditions from the host
side)
3. The above processing is performed and the scanned image data are output to the host
side at the end.
Summary of Contents for Perfection 4870 Photo
Page 1: ...EPSON Perfection4870Photo Color Image Scanner Service Manual SESC03 008 ...
Page 5: ...Revision Status Revision Date of Issue Description A December 10 2003 First release ...
Page 8: ...C H A P T E R 1 PRODUCTDESCRIPTION ...
Page 19: ...C H A P T E R 2 OPERATINGPRINCIPLES ...
Page 29: ...C H A P T E R 3 TROUBLESHOOTING ...
Page 37: ...C H A P T E R 4 DISASSEMBLY ASSEMBLY ...
Page 63: ...C H A P T E R 5 ADJUSTMENT ...
Page 65: ...C H A P T E R 6 MAINTENANCE ...
Page 68: ...C H A P T E R 7 APPENDIX ...
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