Service manual

1.2 PROCESS CONTROL MEASUREMENT TIMING
The machine uses outputs from the drum potential sensor and the ID sensor.
Some outputs are measured every color development cycle during each
copy, and others are only measured during the process control self check
procedure.
The following table shows the sensor outputs that are used by process
control, and the times that these outputs are measured.
Sensor Output: Measurement Timing
V
SG
Adjusted to 4.0 ± 0.1 V during the process
control self check.
V
SP
for toner supply control [V
SP
(toner)] During each copy, after writing each color
image to the drum, the laser diode writes the
ID sensor pattern for toner supply control on
the drum. (This is a single-grade pattern.)
The ID sensor measures the density of the
developed ID sensor pattern for each color,
and this is used as V
SP
(toner).
Drum Potential During the process control self check, the
laser diode writes a 12-grade gradation
pattern for each color on the drum. The
drum potential sensor measures the
potential on each grade.
V
SP
for potential control [V
SP
(pot)] After the above 12-grade gradation pattern
has been developed, the ID sensor
measures the density of the developed
gradation pattern for each step and stores
these values as V
SP
(pot).
NOTE:
V
SG
: Output voltage from the ID sensor when it measures the bare
drum.
V
SP
: Output voltage from the ID sensor when it measures the image
density of a sensor pattern.
Process Control Self Check: See section 4.
Detailed
Section
Descriptions
PROCESS CONTROL
SM 2-3 A166/A187/A189
CÓPIA NÃO CONTROLADA
CÓPIA NÃO CONTROLADA