November 2003 © TOSHIBA TEC 11 - 3 e-STUDIO3511/4511 DRUM RELATED SECTION
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(5) Discharge LED
Discharge is a process to decrease or eliminate the static electricity on the drum surface.
The electrical resistance of the photosensitive layer is decreased by the light, and the residual charge
on the drum surface is neutralized and eliminated (cleaned). Electrical potential of the drum surface
is fixed to a certain amount before the drum is charged.
(6) Toner bag
This collects the residual toner scraped off on the drum surface by the cleaning blade and residual
toner scraped off on the transfer belt by the transfer belt cleaning blade.
(7) Toner bag full detection sensors-1 & -2
The sensor-2 (transmissive type) finds the toner bag full by detecting the volume of used toner in the
toner bag. The sensor-1 detects the toner bag full when it is pushed by the toner recovery auger in
the cleaner which is given a pressure from the used toner in the toner bag.
The toner bag full detection sensor-2 also detects the presence/absence of the toner bag.
“Toner bag full” is determined when either of the toner bag full detection sensors-1 and -2 detects full
of toner. Printing is interrupted upon the detection of “Toner bag full” status, however, the paper
already fed is subject to be printed and exited. When the sensors are in trouble, “Toner bag full” is
determined instead of “Call for service”. If “Toner bag full” status is not cleared, the sensors, harnesses
and LGC board need to be checked.
(8) High-voltage transformer
A circuit generates the output control voltage Vc of the main charger bias, main charger grid bias, 1st
transfer roller bias, 2nd transfer roller bias, black developer bias, color developer bias and cleaning
blade bias.
(9) Image quality sensor
This sensor measures the reflection amount of the test pattern (toner image) formed on the transfer
belt and outputs to the LGC board in order to keep the appropriate image density and line width.
(10) Temperature/humidity sensor
This sensor measures the environment inside the equipment. The values of the temperature and
humidity detected inside the equipment are output to the LGC board.