All energy-consuming products are required to deliver energy-efficient performance to prevent global warming and other issues. In MFPs, heat must be applied when fixing toner on paper. Notably, power consumption of the fixing unit accounts for more than sixty percent of an MFP’s overall power consumption. In order to cut power consumption in the fixing process, Konica Minolta has worked on research and development of toner that can be fixed at a lower temperature as well as on energy conservation of the fixing unit.
If the fixing unit were kept hot all the time, documents could be readily printed; however, this would require high power consumption. Thus, the fixing unit temperature is lowered when an MFP is idling; the temperature is raised only when printing documents.
In MFPs, the warm-up time refers primarily to the time required until the fixing unit is heated to the correct temperature to start printing. It is waste of time to wait a long time for an MFP to start printing after pressing the print button. If the fixing unit could be quickly heated to the correct temperature to start printing, warm-up time would be shortened. It would also allow the idling temperature to be set lower; as a result, standby power consumption would be reduced.
IH technology, which is commonly used in induction cooktops etc., can efficiently convert electricity into thermal energy. Only the required heating component is heated by the IH coil, and therefore energy loss can be minimized. Meanwhile, the temperature of the heating component can be easily controlled by changing the amount of electricity applied to the coil. Energy can be efficiently utilized without using excess or experiencing shortages.
Konica Minolta developed its proprietary IH Fixing technology by combining the IH technology featuring high heating efficiency with a mechanism to reduce the thermal capacity of the heating component that comes into contact with the toner image. The thermal capacity is reduced by using a thin belt as a heating component. The belt is heated with an IH coil to increase heating efficiency and thereby reduce warm-up time. Increased heating efficiency also helps reduce power consumption during printing.
When the thermal capacity of a heating component is reduced, both ends of the heating component are overheated if narrow sheets of paper are fed for printing. To solve this problem, Konica Minolta developed its proprietary demagnetizing coil mechanism to efficiently heat the heating component depending on paper width by adjusting the magnetic flux on both ends.
In the latest models, heating efficiency has been further increased by allowing the magnetic flux generated by the magnetizing coil to be effectively transmitted to the fixing belt. This was achieved by improving (i) the metal heating layer of the fixing belt (the heating component that comes into contact with the toner image) and (ii) the core layout in the IH coil unit.
The improvements in the IH Fixing technology and use of low-temperature fixing toner, in combination with other energy-saving solutions, have achieved the lowest power consumption (TEC value*1) and shortest warm-up time*2 among color MFPs of the same class (black-and-white: 75 ppm, color: 60 ppm).
- *1:A value based on a measuring method specified in the International ENERGY STAR Program. Total amount of energy assumed to be consumed during standard use. (TEC is an acronym of Typical Electricity Consumption.)
- *2:As of February 2012 when the products were released
When narrow sheets of paper are fed for printing, both ends of the fixing belt (the areas outside the paper path) do not lose heat to paper. Therefore they are overheated. To solve this problem, a demagnetizing coil mechanism was employed to cancel the magnetic field generated by the magnetizing coil. The demagnetizing coil circuit generates a repulsive magnetic flux due to the electromagnetic induction effect. This repulsive magnetic flux inhibits heating of the fixing belt in the areas outside the paper path, enabling flexible control of the heating width.
Konica Minolta’s MFPs have built-in proximity sensors to trigger automatic resumption of operation when fingers are near the operation panel. This eliminates the need to resume operation from sleep mode, making it possible to save electricity without sacrificing business efficiency.