15 February 2006 DEVELOPMENT AND TONER SUPPLY
6-75
Detailed
Descriptions
At the end of the job, if Vref has not been updated for 10 copies or more, the
following occurs:
1. Vref is updated, as follows (also done just after the machine is switched on):
• The charge corona and laser diode write the ID sensor pattern on the drum.
• The ID sensor reads the reflectivity of the ID sensor pattern and outputs this
reading as Vsp.
• The ID sensor also reads the reflectivity of the bare surface of the drum and
outputs this reading as Vsg.
NOTE: 1) The 10 copy interval can be extended with SP2210-001 (ID Sensor
Pattern Interval).
2) SP2507-002 (ID Sensor Interval – Page Setting) is available for
customers who are concerned about changes in toner density during
long copy jobs and may want to specify an interval to force creating
and reading the ID sensor pattern. However, enabling this SP will
pause copying for 2 or 3 seconds every time the ID sensor pattern is
created and read.
2. The CPU uses the Vsp/Vsg readings to calculate a new value for Vref (TD
sensor reference voltage).
3. Finally, Vt and Vref are compared. If Vt is higher than Vref, the CPU switches
on the toner supply clutch to supply more toner to the development unit.
Pixel Count Toner Supply Mode
This mode should only be used as a temporary countermeasure while waiting for
replacement parts, such as a TD sensor.
For each copy, the CPU adds up the image data value of each pixel and converts
the sum to a value between 0 and 255 (0 = blank page, 255= black page).
The toner supply clutch on time is calculated using the same formula, but the GAIN
value is fixed at 0.7.
To Next Page
Loading...
Need help?
General
