Auto-Toner Circuit; General Description - Toshiba e-STUDIO555 Service Manual

Control signal of developer unit motor
• DEVON signal:
This signal switches the on/off of the developer unit motor. When this signal moves to a low level,
the motor is rotated, and when this moves to a high level, the motor is stopped.
• DEVCK signal:
This signal is a reference clock which keeps the developer unit motor rotation at a constant speed.
When the cyclic change of the FG pulse period against this reference signal is within ±6.25%, this is
defined as a lock range (= the normal rotation of the motor). When the cyclic change is within this
range, the LED on the driving PC board of this motor is lit.
• DVMBK signal:
This signal applies a brake on the developer unit motor. When this signal moves to a low level, a
brake is applied to the rotation of the motor.

11.5 Auto-toner Circuit

11.5.1

General description

1. Function of the auto-toner circuit
- Detects the toner density in the developer material, and supplies toner when the density is
lowered to a certain level.
- Detects that there is no toner left in the developer unit.
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