Principle Of Image Quality Sensor; Flow Of Control - Toshiba e-STUDIO520 Service Manual

11.4.3

Principle of Image Quality Sensor

The image quality sensor applies the light to the drum and test pattern (toner image) developed on the
drum and outputs the voltage corresponding to its reflected light amount.
Toner amount on the drum is calculated from the reflected light amount obtained by this sensor.
Light emitting element
Test pattern
(Toner image)
11.4.4

Flow of control

Start controlling (e.g. during the pre-running after the power has been turned ON)
[1] Setting of the reference image formation condition
[2] Adjustment of the sensor
[3] Formation of the test pattern
[4] Reading of the value for the image quality sensor
[5] Determination
(Is the toner amount of the test pattern within the permissible amount?)
YES NO
[6] Changing of the image formation condition
[7] Finish controlling
(Reflecting the determined image formation condition to the following printing)
March 2005 © TOSHIBA TEC
Image quality sensor
Light sensing element
Drum
Fig.11-4
11 - 5
Light source intensity signal
Reflected light intensity signal
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e-STUDIO520/600/720/850 DRUM/CLEANER UNIT
11