Power supply device, heating unit using same, and image forming apparatus using said heating unit
US8401417B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Nov 2, 2010 |
| Grant date | Mar 19, 2013 |
| Priority date | — |
| Expiry date | Jan 10, 2031 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02B70/10
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
The invention reduces loss produced when a power supply device supplies power to a fixing unit of a copier, thereby contributing to a reduction in size, a saving in terms of energy and lower cost. To achieve this, it is arranged so that it is possible to vary the capacitance of a resonant capacitor C200 that constructs a resonant circuit together with a coil 71 through which a high-frequency current flows in order to produce an induced electromotive force in an electrically conductive heating element. In an interval in which a tail current flows after closure of an IGBT 401 that switches the coil current, the capacitance of the resonant capacitor C200 of a switching element SW402 is increased, thereby suppressing a rise in voltage Vce of the IGBT 40 over a fixed interval of time. As a result, loss ascribable to the tail current is reduced.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.