This issue shares the working principle of the Konica Minolta color machine "fixing unit". The reference model is C364.
In the Konica Minolta office color machine, the fixing appears in the form of a component, and the fixing component must be replaced when it reaches the end of its life. Fixing has two functions: heating and pressurization. Heating melts the toner and releases pressure to fix the toner on the paper.
Drive
The fixing is driven by the fixing motor to rotate: the fixing pressure motor is responsible for the pressure roller pressurization and retraction.
Fusing temperature control
The heating roller contains a fusing heater lamp assembly. When the fusing heater lamp is turned on, it generates heat, which heats the heating roller and the fusing belt. The fusing heater lamp consists of two heaters, which have different temperature heating ranges.
- Fusing heater lamp 1 (long) can evenly heat the entire surface of the heating roller.
- Fusing heater lamp 2 (short) only heats the center of the heating roller.
The fusing heater lamp turns on or off according to the paper width and the surface temperature of the fusing belt.
- For paper widths of 209 mm or less, the center is heated using fusing heater lamp 2.
- For paper widths exceeding 209 mm, the surface temperature of the fusing belt is measured and fusing heater lamp 1 and fusing heater lamp 2 are turned on alternately.
Examples of fixing temperature control in different time periods:
Prevent image fixing performance degradation and avoid problems such as paper curling, uneven imaging and offset. The fixing temperature can be fine-tuned in the maintenance mode according to the paper type.
Fixing uses thermistors, temperature sensors and thermostats to control the fixing temperature. When the temperature is abnormal, 3 protection methods are provided:
- Software protection: When thermistors, fixing temperature sensors detect abnormally high temperatures, the CPU reports a fault code and the machine is prohibited from printing.
- Hardware protection: When the CPU is overloaded, protection cannot be provided. When the fixing temperature sensor detects abnormal main temperature, the heater relay of the DC power supply will be turned off through the printed circuit board and a fault code will be reported.
- Thermostat protection: If abnormally high temperatures cannot be detected through steps 1 and 2 above, the thermostat will work and cut off the power supply to the heating lamp.
Fusing Cooling Control
Uses the toner bottle cooling fan to cool the area around the fusing unit inside the machine. Air is drawn in from the outside to the rear of the machine and blown between the fusing unit and toner bottle unit for cooling.
Fusing speed correction
To avoid fluctuations in paper transport speed during image transfer and fusing, which can lead to double transfer images and brush effects, a wave control is provided between the second transfer and fusing (paper transport and fusing rotation are controlled by different motors)
- The fusing wave sensor detects the paper wave length between the second transfer section and the fusing roller.
- The fusing motor increases or decreases the fusing speed according to the wave length on the paper, thereby ensuring that the wave length is within the specified range.
- Depending on the paper type, it can also be adjusted manually in the maintenance mode. Large wave speeds up; small wave speeds down.
Service life
The fuser unit service life counter controls the service life of the fuser unit. When the print counter value reaches the threshold, the machine determines that the fixing unit has entered a new state.
When the print counter or fixing rotation time counter value reaches the service life threshold (printing is possible, but beyond the image quality guarantee range), the service life arrival screen will be displayed.
When the print page counter value reaches the service life end threshold (printing is prohibited), the service life end screen will be displayed.
The fixing unit is not equipped with any new parts detection mechanism. When a new fixing component is replaced, it is necessary to perform the "new product release" (counter reset) operation in the maintenance mode.
Conclusion:
The fixing unit in the Konica Minolta C364 is vital for achieving high-quality prints by ensuring proper toner adhesion through precise heating and pressurization. Regular maintenance, including temperature adjustments and speed corrections, is crucial to prevent issues such as paper curling, uneven imaging, and offset. Understanding the service life of the fixing unit and performing necessary resets during part replacements ensures the longevity and reliability of your printer.