Automatic Black Level Correction - Sharp AL-2021 Service Manual

7. Automatic black level correction

a. Cases when the adjustment is required
1) When the main PWB is replaced.
2) When the EEPROM in the main PWB is replaced.
3) When "U2" trouble occurs.
4) When repairing or replacing the optical section.
b. Adjustment procedure
Used to acquire the black level target value used for the black level
adjustment of white balance.
When SIM 63-02 is executed, the current correction value is dis-
played in 3 digits of 12bit hexadecimal number.
Place the gray gradation chart (UKOG-0162FCZZ) used as the
correction document so that the density 10 (black side) comes on
the left side and that the chart is upside down at the center of the
plate left center.
10
Chart back surface
When START key is pressed, the mirror base unit scans the chart
and calculates the correction value.
After completion of correction, the corrected value is displayed on
the display section.
* Default: 0
* If the value is set to the default, operation is made with 0x60.
AL-2041 ADJUSTMENTS 9 - 8