Develop QC 2235 Plus Service Manual page 120

Image processing
• The following detail the image processing operations performed by MFP Control Board
on the Write Section.
1. Each image area, whether it is a color edge area, black edge area, dot area, or a con-
tinuous gradation area, is discriminated to optimize edge emphasis and smoothing just
right for the image.
2. The color component data are converted to the Y, C, M, and Bk density data. Also, the
masking processing, which compensates for the deviation in the spectral reflection
characteristics of the toner, and UCR/BP processing are performed on the image data.
3. Other types of processing performed are the improved reproduction of black text, edge
emphasis, edge expansion, smoothing, color balance, and γ correction.
4. Compresses the C, M, Y, and Bk image data to reduce its volume.
5. Temporarily stores the GBTC-compressed image data.
6. Stores the compressed image data.
7. Spreads out the image data stored in the file memory to the frame memory and per-
forms the following control functions: delaying outputs to make up for the distance
between the PC Drums of Y, M, C, and Bk and adjusting the different speeds between
the Scanner and the Write Section.
8. Stores the Y, M, C, and Bk image data.
9. Temporarily stores the image data output from the frame memory.
10. Corrects skew in the print position at 600 dpi to ensure correct alignment in the main
scanning direction between each of the Y, M, C, and Bk LPH assemblies and the PC
Drums.
11. Corrects any deviation in the print start position in the main scanning direction that
occurs when each of the Y, M, C, and Bk LPH assemblies illuminates the surface of the
corresponding PC Drum.
12. Expands the image data using the method opposite to that used in GBTC compression.
13. Corrects skew in the print position at 1,800 dpi to ensure correct alignment in the main
scanning direction between each of the Y, M, C, and Bk LPH assemblies and the PC
Drums.
14. Discriminates the edges of text and line figures and, according to the results of the area
discrimination, performs the Fine Edge Enhanced Technology (FEET) operation.
15. In order to prevent the gradation balance from changing, interpolation converts the res-
olution only for the continuous gradation areas when resolution changes from 600 dpi
to 1,800 dpi when using FEET.
16. Makes the necessary corrections so that the printed gradations have linear characteris-
tics, since the image density of the input image data is not directly proportional to that
of the printed image because of the changing developing and PC Drum characteristics.
17. Creates the density distribution of a predetermined pattern to enable outstanding gra-
dation reproduction.
18. Rearranges the image data, which has undergone the processes up to screening, so
that the LEDs can then be illuminated and transfer the corrected image data.
19. Adjusts the variations in each of the LEDs, approx. 7,700 chips, to ensure that each
emits a uniform intensity of light.
QC 2235plus Theory of Operation Ver.1.0 Feb. 2004
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