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US 2010/0149840 A1Published application
Power supply apparatus and image forming apparatus
AssigneeCanon Kabushiki Kaisha
InventorsMinoru Hayasaki, Keisuke Samejima
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Abstract
The power supply apparatus for obtaining a direct current from an alternating voltage source includes a first DC/DC converter for outputting a first direct current and a second DC/DC converter for a second direct current lower than the first direct current from the first DC/DC converter, and the output voltage of the first DC/DC converter is changed to a lower direct current and the second DC/DC converter is driven in a continuously-conducting state.
Claims7
A power supply apparatus for obtaining a direct current voltage from an alternating voltage source, comprising:
- a rectification smoothing unit electrically connected to the alternating voltage source for rectifying and smoothing an alternating current voltage from the alternating voltage source;
- a first DC/DC converter for converting the direct current voltage from the rectification smoothing unit and outputting a first direct current voltage;
- a second DC/DC converter, receiving the first direct current voltage from the first DC/DC converter, for outputting a second direct current voltage lower than the first direct current voltage through switching operation of a switching unit;
- and
- a transit unit for making a transit to a state in which an output voltage of the first DC/DC converter decreases from the first direct current voltage to a third direct current voltage lower than the second direct current voltage and the switching unit of the second DC/DC converter is driven in a continuously-conducting state.
2 more elements
An image forming apparatus comprising:
- a driving part driven to form an image;
- a control part for controlling operation of the driving part;
- and
- a power supply part for obtaining a direct current voltage from an alternating voltage source to operate the driving part and the control part, the power supply part including:
- a rectification smoothing unit electrically connected to the alternating voltage source for rectifying and smoothing an alternating current voltage from the alternating voltage source;
- a first DC/DC converter for converting the direct current voltage from the rectification smoothing unit and outputting a first direct current to the driving part;
- a second DC/DC converter, receiving the first direct current from voltage the first DC/DC converter, for outputting to the control part a second direct current voltage lower than the first direct current voltage through switching operation of a switching unit;
- and
- a transit unit for making a transit to a state in which an output voltage of the first DC/DC converter decreases from the first direct current voltage to a third direct current voltage lower than the second direct current voltage and the switching unit of the second DC/DC converter is driven in a continuously-conducting state, when the image forming apparatus is brought into an energy-saving mode in response to a command from the control part.
6 more elements
Dependencies are inferred from the claim text.