Digital Voltmeter - Scan-Graphics CF Series Maintenance Manual

6.6 TASK -- CAMERA CALIBRATION
The following conditions require calibration of the scanner's cameras:
Replacement of any of the following components:
All of the software tools for camera calibration are contained in the Camera System
Diagnostics. Refer to the Diagnostics Tests software section 5.1.14 for details. The following
calibrations must be performed to perfect the scanned image:
1. Adjust Video Board.
2. Adjust camera board offsets.
3. Calibrate camera exposures.
4. Calibrate camera gains.
6.6.1 Video Board Adjustments
Equipment, Tools & Materials required:
• Small flat head screwdriver or potentiometer tweaker

• Digital voltmeter

Procedure for Adjusting Video Board:
1. Connect to negative lead of the voltmeter to TP4 on the Video Board.
2. Place the positive lead of the voltmeter on U5 pin 7.
3. Adjust potentiometer R21 until the voltage is zero.
4. Place the positive lead of the voltmeter on U5 pin 10.
5. Adjust potentiometer R20 until the voltage is zero.
6. Move JP1 and JP2 to their lower positions (position 2).
7. Activate "AUTOTAKE", and enter camera number 0. See section 5.1.14.9 for details.
8. You should either see all zeros or some numbers on the screen
9. If you see all zeros, turn the potentiometer R34 until you start to see non-zero numbers.
10.As you observe the display, turn the potentiometer just until you see zeros come up on
the screen.
11.Move JP1 and JP2 back to their upper positions (position 1).
CCD Camera Board
Video Board
Imaging Lamp
Detection of image degradation
Adjustment of +5 V, or +12 V Linear power supply voltages.