Sbu (Sensor Board Unit); Operation Summary; Storing Operation Settings; Sbu Test Mode - Ricoh B132 Service Manual

6.6.2 SBU (SENSOR BOARD UNIT)

SBU
The VPU (Video Processor Unit) does the following functions:
• Black level correction
• White level correction
• Gradation calibration
• ADS control (Background Density)
• Creating the SBU test pattern

Operation Summary

The signals from the 3-line CCD, one line for each color (R, G, B) and 2 analog
signals per line (ODD, EVEN), are sampled by the ASIC and converted to digital
signals in the 10-bit A/D converter. This is the first phase of processing the data
scanned from the original.

Storing Operation Settings

The controller stores the SBU settings. These values must be restored after the
lens block is replaced:
SP4008 001 Sub Scan Mag
SP4010 001 Sub Scan Reg
SP4011 001 Main Scan Reg
Also, before lens block replacement, enter the SP mode and note the settings of
SP4800 001 to 003 (ARDF density adjustments for R, G, B). After lens block
replacement, do some copy samples with the ARDF, then check the copies. If the
copies have background, change SP4800 001 to 003 to their previous settings, or
adjust until the background is acceptable. These SP codes are also used to adjust
the ARDF scanning density, if the scanning densities of the ARDF and the platen
mode are not the same.

SBU Test Mode

There are two SP codes to create a test pattern which can be used as a diagnostic
tool to troubleshoot problems in the SBU:
• SP4907 001 SBU Pattern - Test Pattern
• SP4907 002 SBU Pattern - Select Fixed Pattern
To print the pattern:
• Select the pattern to print.
• Touch "Copy Window" then press the Start key twice.
SM
Sub Scan Magnification Adjustment
Sub Scan Registration Adjustment
Main Scan Registration Adjustment
6-41
IMAGE PROCESSING
B132/B200