Q1860-90918 Chapter 5 Functional information 75
Toner-cartridge detection
The toner cartridge has a toner sensor. The circuit compares the output value of the developing
ac bias and the output value (ANT) from the antenna inside the cartridge, and puts out the toner-
detection signal.
The CPU detects the level of remaining toner and the presence of the cartridge when the
developing bias is applied to the developing cylinder. The level of remaining toner is always
detected when the developing bias is applied. The presence of the cartridge is detected only
when the developing bias is applied during the initial rotation.
Dc controller system
The following systems and functions are controlled by the dc controller PCA:
Dc power distribution (+3.4 Vdc, +5 Vdc, +24 VA)
Laser and scanner drive
Paper-motion monitoring and control (photosensors and flags)
Clutches (tray pickup and Tray 1 feed)
Engine test
Motors (main drive, scanner, and fans)
The CPU of the dc controller system regulates the operation sequences of this printer. When the
printer power switch is turned on and the printer enters the standby mode, the CPU sends the
signals to drive the loads (such as laser diode, motors, and solenoids) based on the print
commands and the image data received from the formatter.
Figure 12. Dc controller PCA
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