Power supply device, image forming apparatus, and power supply method
First Claim
Patent Images
1. An image forming apparatus comprising:
- a capacitor that is charged by an external power source, and dischargably stores therein power;
a load that receives supply of power;
a control unit that controls the load;
a switching unit that switches power sources to supply power to the load and the control unit between the external power source and the capacitor;
a detecting unit that detects whether the voltage of the external power source has dropped below a first or second threshold level; and
a power supply unit thatcauses the switching unit to switch the power source to supply power to the load and the control unit from the external power source to the capacitor when the detecting unit detects that the voltage of the external power source has dropped below the first threshold level, and supplies power to the load and the control unit, andcauses the capacitor to supply power to the load and the control unit before a voltage of the external power source drops below the second threshold level where malfunction of any one of the load and the control unit occurs, and stops the supply of power from the capacitor to the load and the control unit after the voltage exceeds the first threshold level.
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Abstract
A power supply device supplies power to an image forming apparatus. The image forming apparatus includes a load and a control unit. The load requires power, and is controlled by the control unit. The power supply includes a capacitor and a power-supply unit. The capacitor is charged by an external power source, and dischargably stores therein power. The power-supply unit provides power supply from the capacitor to the load and the control unit before voltage of the external power source drops below a threshold level where malfunction of the image forming apparatus occurs. After the voltage recovers to the threshold level, the power-supply unit stops the power supply from the capacitor.
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Citations
14 Claims
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1. An image forming apparatus comprising:
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a capacitor that is charged by an external power source, and dischargably stores therein power; a load that receives supply of power; a control unit that controls the load; a switching unit that switches power sources to supply power to the load and the control unit between the external power source and the capacitor; a detecting unit that detects whether the voltage of the external power source has dropped below a first or second threshold level; and a power supply unit that causes the switching unit to switch the power source to supply power to the load and the control unit from the external power source to the capacitor when the detecting unit detects that the voltage of the external power source has dropped below the first threshold level, and supplies power to the load and the control unit, and causes the capacitor to supply power to the load and the control unit before a voltage of the external power source drops below the second threshold level where malfunction of any one of the load and the control unit occurs, and stops the supply of power from the capacitor to the load and the control unit after the voltage exceeds the first threshold level. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A power supply device for an image forming apparatus including a load that receives supply of power and a control unit that controls the load, the power supply device comprising:
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a capacitor that is charged by an external power source, and dischargably stores therein power; a switching unit that switches power sources, to supply power to the load and the control unit of the image forming apparatus, between the external power source and the capacitor; and a detecting unit that detects whether the voltage of the external power source has dropped below a first or second threshold level; and a power supply unit that causes the switching unit to switch the power source to supply power to the load and the control unit from the external power source to the capacitor when the detecting unit detects that the voltage of the external power source has dropped below the first threshold level, and supplies power to the load and the control unit, and causes the capacitor to supply power to the load and the control unit before a voltage of the external power source drops below the second threshold level where malfunction of any one of the load and the control unit occurs, and stops the supply of power from the capacitor to the load and the control unit after the voltage exceeds the first threshold level.
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14. A power supply method of supplying power to an image forming apparatus, the apparatus including a load receiving supply of power and a control unit that controls the load, the power supply method comprising:
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charging a capacitor by an external power source; switching power sources, to supply power to the load and the control unit of the image forming apparatus, between the external power source and the capacitor; detecting whether the voltage of the external power source has dropped below a first or second threshold level; switching the supply power to the load and the control unit from the external power source to the capacitor when the detecting that the voltage of the external power source has dropped below the first threshold level, and switching the supply power to the load and the control unit from the external power source to the capacitor before a voltage of the external power source drops below the second threshold level where malfunction of any one of the load and the control unit occurs, and stopping the supply of power from the capacitor to the load and the control unit after the voltage exceeds the first threshold level.
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Specification