17 January, 2003 PROCESS CONTROL
6-15
Detailed
Descriptions
6.2.4 VREF COMPENSATION DURING A PRINT JOB
Highlight Pattern
The M/A target (mass-per-area target) is the target toner amount in a given area.
To adjust the toner amount, a highlight pattern [B] is created on the transfer belt at
the following times during each print job.
Job Interval Color of highlight pattern
Black-and-white printing After every four pages Black
Color printing After every one page One of four colors
For color jobs, the order of pattern generation is K → Y → M → C → K → Y → M
→ C.... The highlight pattern is created about 2 cm after the trailing edge of the
paper [A].
Adjustment Process
The machine generates a highlight pattern (just one grade) of a specified density.
The center ID sensor checks the density and the machine adjusts V
REF
by
comparing the reading with the target of each color (SP3-905-1 to 4).
Left
Transfer belt
G080D986.WMF
[A]
[B]