SBU

Functions

Performs Black level correction and White level correction, Creating the SBU test pattern, and A/D conversion.

This machine is equipped with a short focus scanner and the SBU is located on the scanner carriage.

Operation overview

Samples 2 analog signals (ODD, EVEN) from RGB output from the 3-line CCD, and converts them to digital signals by an A/D converter. The digital signals are output to the BICU (IPU).

SP correction value storage

The SBU correction value is stored in an EEPROM on the BICU.

Execute the following SP settings when the scanner carriage is replaced. (Lens block is located on the scanner carriage.)

• SP4-871-002 (Distortion Correction Distortion Initialization)
• SP4-880-001 (Dot shift amount between R Line and G Line).
• SP4-880-002 (Dot shift amount between G Line and B Line).

SBU Test Mode

There is an SP code to create a test pattern which can be used as a diagnostic tool to troubleshoot problems in the SBU:

• SP4-699-001 (SBU Test Pattern Change)
  Pattern 1: fixed value
  Pattern 2: main scanning gradation pattern
  Pattern 3: width scanning gradation pattern
  Pattern 4: main scanning/width scanning lattice pattern
  SBU has a function to generate four test patterns.