OPERATING PRINCIPLES
Rev. A
2-11
Figure 2-15 shows the sequence of operations, starting from the point where image data is input
into the FilmScan 200, and ending with the output of image data to a computer.
1.
The lamps light, and the scanner reads the white standard attached to the inverter lamp cover via
slit of film carrier.
2.
The lamps turns off, and the scanner reads the black standard.
3.
The lamps light. Light passes image frame on the film is read by the CCD sensors.
4.
The data that has been read in is amplified.
5.
The amplified analog image data is converted to 10-bit digital data by the 10-bit A/D converter.
6.
Shading correction is applied to the 10-bit digital data. The white and black standards [read in
steps 1 and 2, above] determine the shading correction.
Notes: Shading Correction
The image data sent out by the sensor is derived by direct photoelectric conversion of the reflected light
that impacts the sensors. This data must be further converted before it can be output from the device
(e.g., before it cam be used for reproducing the image on a CRT). The use of white and black standards in
performing this type of conversion is referred to as “shading correction.'' The correction value is
determined from the following expression:
(image data - black standard) / (white standard - black standard)
In other words, image data is calculated in-terms of its-proportional relation to white data. This scanner
converts data format from 10-bit to 8-bit at the “shading correction.”
7.
Gamma correction, color correction, zoom correction, and half-toning are performed, based on
commands sent from the computer (they re selected and adjusted by the TWAIN driver).
8.
Image data is output to the computer device, such as monitor or printer.
Original
Image Frame
CCD
AMP.
Optical Unit
A/D
Converter
Shading
Correction
8 bits/ pixel Gamma
Correction
Color
Correction
Zoom
Halftoning
Data
Output
10-Bit / Pixel
Figure 2-15. FilmScan 200 Operation Outline
Summary of Contents for FILMSCAN 200
Page 1: ...EPSON FILM SCANNER FilmScan 200 SERVICE MANUAL SEIKO EPSON CORPORATION 4007375 ...
Page 5: ...v REVISION SHEET Revision Issued Data Contents Rev A FEBRUARY 28 1997 First issue ...
Page 8: ...EPSON SEIKO EPSON CORPORATION ...
Page 75: ...CHAPTER 4 ADJUSTMENT No adjustment is required in this product ...
Page 85: ...CHAPTER 6 MAINTENENCE 6 1 MAINTENENCE 6 1 6 2 LUBRICATION 6 1 ...
Page 86: ...APPENDIX A 1 CONNECTOR PIN ASSIGNMENTS 1 A 2 EXPLOED DIAGRAM 8 ...
Page 88: ...FilmScan 200 Rev A A 2 Figure A 2 Cable Connection SCSI Model ...
Page 95: ...APPENDIX Rev A A 9 Figure A 4 FilmScan 200 Bi D Model Exploded Diagram 2 2 ...
Page 96: ...FilmScan 200 Rev A A 10 Figure A 5 FilmScan 200 SCSI Model Exploded Diagram 1 2 ...
Page 97: ...APPENDIX Rev A A 11 Figure A 6 FilmScan 200 SCSI Model Exploded Diagram 2 2 ...
Page 98: ...FilmScan 200 Rev A A 12 Figure A 7 APS Holder option Exploded Diagram ...
Page 100: ...FilmScan 200 Rev A 6 2 Shaft 1 G 36 1 G 36 Figure 6 1 Lubrication Points ...
