Automatic Black Level Correction - Sharp AL-1661CS 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 test command 63-02 is executed, the current correction value is
displayed 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 [ENTER/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
LCD.
* Default: 0
* If the value is set to the default, operation is made with 0x60.
c. Operation
1) Initial display
63-02 BLACK LEVEL
0
2) [ENTER/START] Correction start
63-02 BLACK LEVEL
EXECUTING...
<During canceling - When C/CA is pressed->
After canceling, the machine goes into the sub code entry standby
mode.
THE JOB IS BEING
CANCELED.
3) After execution
63-02 BLACK LEVEL
*** OK
3) In case of an error
63-02 BLACK LEVEL
*** ERR
AL-1661CS ADJUSTMENTS 9 - 8