Image Processing Pc Board (Img) - Toshiba e-STUDIO2330C Service Manual

8.3

Image Processing PC Board (IMG)

8.3.1 Features
1. Image processing functions realized on the IMG board are controlled by the CPU on the SYS board.
2. The image processing PC board realizes the following functions:
- ACS
- Color conversion (CMY image data processing)
- Black component generation
- High quality image processing
- Image memory editing
- Rectangular area signal generation
- Editing processing
- Gamma correction
- Gradation processing
- Compression/expansion
- Blank page detection
- Outside erase
- Smoothing processing
- Scanner high quality image processing
- Printer high quality image processing
8.3.2 Functions of image processing circuit
1. ACS (Auto Color Selection)
This function determines whether the original to be scanned is colored or monochrome, based on
the analysis of the R, G and B signals output from the CCD.
2. Color conversion (CMY image data processing)
When functioning the copier, the RGB image data is converted to CMY image data. (When
functioning the scanner, it is converted to RGB image data.)
The image data taken in by the scanner represents the intensities of reflection from the three
primary colors of light (Red, Green and Blue). These RGB values are then color-converted to the
respective amounts of toners corresponding to the three colors (Yellow, Magenta and Cyan) for
printing (=CMY image data processing).
3. Black component generation
K (Black) signal is generated from the CMY image data. Based on this K signal, the CMY image
data is corrected to suppress hue on reproducing grays or to make the black look more real.
4. High quality image processing
- Background processing function
By using the background adjustment function while manually adjusting the image density,
undesirable background of the original can be removed if any, and some necessary but
disappeared background can be recovered. By using this function, it is possible to cut the
background density down when copying originals which have a certain level of background
density, such as newspapers.
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IMAGE PROCESSING
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