POWER SUPPLY DEVICE AND IMAGE FORMING APPARATUS HAVING THE SAME
First Claim
1. A power supply device configured to operate in one of a normal operation mode and a power-saving mode, comprising:
- a first load configured to operate with a first voltage supplied thereto in the normal operation mode;
a second load configured to operate with a second voltage supplied thereto in the normal operation mode, the second voltage being lower than the first voltage;
a third load configured to operate with the second voltage supplied thereto in both the normal operation mode and the power-saving mode;
a main power supply circuit configured to output, as a main supply voltage, at least one of the first voltage and the second voltage in response to an operation mode switching signal input thereinto, the main power supply circuit switching the main supply voltage to the first voltage when the operation mode switching signal is a signal indicating the normal operation mode, the main power supply circuit switching the main supply voltage to the second voltage when the operation mode switching signal is a signal indicating the power-saving mode;
a first-load electric path configured to carry therethrough the main supply voltage from the main power supply circuit to the first load;
a primary second-voltage generating circuit configured to, when the main supply voltage is supplied thereto from the main power supply circuit and the main supply voltage is lower than the first voltage and equal to or higher than a predetermined threshold value higher than the second voltage, be allowed to generate the second voltage from the main supply voltage and supply the generated second voltage to the second load and the third load;
a third-load electric path configured to carry therethrough the main supply voltage from the main power supply circuit to the third load without passing through the primary second-voltage generating circuit;
a switch circuit configured to make the third-load electric path when the operation mode switching signal is changed to the signal indicating the power-saving mode and a predetermined path-making condition is satisfied, and to break the third-load electric path when the operation mode switching signal is changed to the signal indicating the normal operation mode and a predetermined path-breaking condition is satisfied; and
an auxiliary second-voltage generating circuit configured to, when the main supply voltage is supplied from the main power supply circuit and the primary second-voltage generating circuit is forbidden to generate the second voltage with the third-load electric path being broken by the switching circuit, generate the second voltage from the main supply voltage and supply the generated second voltage to the third load.
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Accused Products
Abstract
A power supply device is provided, which includes a first load operating with a first voltage in a normal operation mode, a second load operating with a second voltage lower than the first voltage in the normal operation mode, a third load operating with the second voltage in the normal operation mode and a power-saving mode, and an auxiliary second-voltage generating circuit configured to, when a main supply voltage is supplied from a main power supply circuit and a primary second-voltage generating circuit is forbidden to generate the second voltage with a third-load electric path for carrying therethrough the main supply voltage from the main power supply circuit to the third load without passing through the primary second-voltage generating circuit being broken by a switching circuit, generate the second voltage from the main supply voltage and supply the generated second voltage to the third load.
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Citations
19 Claims
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1. A power supply device configured to operate in one of a normal operation mode and a power-saving mode, comprising:
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a first load configured to operate with a first voltage supplied thereto in the normal operation mode; a second load configured to operate with a second voltage supplied thereto in the normal operation mode, the second voltage being lower than the first voltage; a third load configured to operate with the second voltage supplied thereto in both the normal operation mode and the power-saving mode; a main power supply circuit configured to output, as a main supply voltage, at least one of the first voltage and the second voltage in response to an operation mode switching signal input thereinto, the main power supply circuit switching the main supply voltage to the first voltage when the operation mode switching signal is a signal indicating the normal operation mode, the main power supply circuit switching the main supply voltage to the second voltage when the operation mode switching signal is a signal indicating the power-saving mode; a first-load electric path configured to carry therethrough the main supply voltage from the main power supply circuit to the first load; a primary second-voltage generating circuit configured to, when the main supply voltage is supplied thereto from the main power supply circuit and the main supply voltage is lower than the first voltage and equal to or higher than a predetermined threshold value higher than the second voltage, be allowed to generate the second voltage from the main supply voltage and supply the generated second voltage to the second load and the third load; a third-load electric path configured to carry therethrough the main supply voltage from the main power supply circuit to the third load without passing through the primary second-voltage generating circuit; a switch circuit configured to make the third-load electric path when the operation mode switching signal is changed to the signal indicating the power-saving mode and a predetermined path-making condition is satisfied, and to break the third-load electric path when the operation mode switching signal is changed to the signal indicating the normal operation mode and a predetermined path-breaking condition is satisfied; and an auxiliary second-voltage generating circuit configured to, when the main supply voltage is supplied from the main power supply circuit and the primary second-voltage generating circuit is forbidden to generate the second voltage with the third-load electric path being broken by the switching circuit, generate the second voltage from the main supply voltage and supply the generated second voltage to the third load. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A power supply device configured to operate in any of:
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a normal operation mode in which the power supply device supplies a first load with a first voltage to operate the first load, and supplies each of a second load and a third load with a second voltage lower than the first voltage to operate the second load and the third load; and a power-saving mode in which the power supply device supplies the third load with the second voltage to operate the third load, the power supply device comprising; a main power supply circuit configured to output, as a main supply voltage, at least one of the first voltage and the second voltage in response to an operation mode switching signal input thereinto, the main power supply circuit switching the main supply voltage to the first voltage when the operation mode switching signal is a signal indicating the normal operation mode, the main power supply circuit switching the main supply voltage to the second voltage when the operation mode switching signal is a signal indicating the power-saving mode; a first-load electric path configured to carry therethrough the main supply voltage from the main power supply circuit to the first load; a primary second-voltage generating circuit configured to, when the main supply voltage is supplied thereto from the main power supply circuit and the main supply voltage is lower than the first voltage and equal to or higher than a predetermined threshold value higher than the second voltage, be allowed to generate the second voltage from the main supply voltage and supply the generated second voltage to the second load and the third load; a third-load electric path configured to carry therethrough the main supply voltage from the main power supply circuit to the third load without passing through the primary second-voltage generating circuit; a switch circuit configured to make the third-load electric path when the operation mode switching signal is changed to the signal indicating the power-saving mode and a predetermined path-making condition is satisfied, and to break the third-load electric path when the operation mode switching signal is changed to the signal indicating the normal operation mode and a predetermined path-breaking condition is satisfied; and an auxiliary second-voltage generating circuit configured to, when the main supply voltage is supplied from the main power supply circuit and the primary second-voltage generating circuit is forbidden to generate the second voltage with the third-load electric path being broken by the switching circuit, generate the second voltage from the main supply voltage and supply the generated second voltage to the third load.
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11. An image forming apparatus comprising a power supply device configured to operate in one of a normal operation mode and a power-saving mode, the power supply device comprising:
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a first load configured to operate with a first voltage supplied thereto in the normal operation mode, the first load comprising a driving unit configured to drive an image forming unit for perform image formation on a recording medium; a second load configured to operate with a second voltage supplied thereto in the normal operation mode, the second voltage being lower than the first voltage, the second load comprising a controller configured to control the driving unit; a third load configured to operate with the second voltage supplied thereto in both the normal operation mode and the power-saving mode, the third load comprising a switching signal output unit configured to output, as an operation mode switching signal, a signal indicating the power-saving mode when a predetermined power-saving mode transition condition is satisfied and to output, as the operation mode switching signal, a signal indicating the normal operation mode when a predetermined normal operation mode transition condition is satisfied; a main power supply circuit configured to output, as a main supply voltage, at least one of the first voltage and the second voltage in response to the operation mode switching signal input thereinto, the main power supply circuit switching the main supply voltage to the first voltage when the operation mode switching signal is a signal indicating the normal operation mode, the main power supply circuit switching the main supply voltage to the second voltage when the operation mode switching signal is a signal indicating the power-saving mode; a first-load electric path configured to carry therethrough the main supply voltage from the main power supply circuit to the first load; a primary second-voltage generating circuit configured to, when the main supply voltage is supplied thereto from the main power supply circuit and the main supply voltage is lower than the first voltage and equal to or higher than a predetermined threshold value higher than the second voltage, be allowed to generate the second voltage from the main supply voltage and supply the generated second voltage to the second load and the third load; a third-load electric path configured to carry therethrough the main supply voltage from the main power supply circuit to the third load without passing through the primary second-voltage generating circuit; a switch circuit configured to make the third-load electric path when the operation mode switching signal is changed to the signal indicating the power-saving mode and a predetermined path-making condition is satisfied, and to break the third-load electric path when the operation mode switching signal is changed to the signal indicating the normal operation mode and a predetermined path-breaking condition is satisfied; and an auxiliary second-voltage generating circuit configured to, when the main supply voltage is supplied from the main power supply circuit and the primary second-voltage generating circuit is forbidden to generate the second voltage with the third-load electric path being broken by the switching circuit, generate the second voltage from the main supply voltage and supply the generated second voltage to the third load. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19)
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Specification