The CPB controls the following scanning-process control signals:

●ADF unit and scan unit operation

•directs the scanner controller board about when to scan

•directs the scanner controller board about how to scan

•directs the scanner controller board about when to activate motors

•directs the scanner about when to turn the scanning lamp on and off

●Image processing

•color alignment

•resolution conversion

•image sharpening

•moire removal

•image scaling

•shifting of data strips (reconstructing separately processed image data before CPB communication to the formatter)

•RGB conversion for CPB communication

•CPB communication over the high-speed copy connect cable to the formatter in one of the following formats:

•Hardware Ready Bits (HRB) (fastpath) communication with the hard disk on the formatter

•PCL-XL (N-up, rotation, book mode) communication with the hard disk on the formatter

•JPEG compression (when sending data digitally) communication with the hard disk on the formatter

•data compression before sending to the formatter over the high-speed copy connect cable

Typical scanning-process flow

1The original document is placed on the glass or in the ADF.

2The user selects job preferences by using the control-panel buttons and keys. The user presses the START button. Job preferences are sent to the formatter.

3Some job preferences are held and then processed later (for example, N-up) by the formatter. Others are sent to the CPB.

4The CPB sends control signals to the scanner controller board. The document is scanned.

5The scanner controller board sends scanned-image data back to the CPB.

6The CPB processes the image.

7The CPB sends the image data to the formatter.

8The formatter further processes the image data (if required).

9The image data is then either printed or sent digitally, depending on what the user specified at the beginning of the process.

58 Theory of operation

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