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US 10,320,299 B2Granted
Power supply apparatus and image forming apparatus controlling a turn-on duty of a switching element for switching a voltage state
AssigneeCanon Kabushiki Kaisha
InventorsYasuhiro Shimura, Hiroki Asano
Life of this patent
Estimating the term…
Abstract
The power supply apparatus includes a control unit configured to perform control of gradually changing a turn-on duty of a first switching element when a first voltage mode is switched to a second voltage mode or when the second voltage mode is switched to the first voltage mode.
Claims17
A power supply apparatus comprising:
- a transformer including a primary winding and a secondary winding;
- a first switching element connected in series to the primary winding of the transformer;
- a second switching element connected in parallel to the primary winding of the transformer;
- a capacitor connected in series to the second switching element, and is connected in parallel to the primary winding of the transformer together with the second switching element;
- a smoothing and rectifying unit configured to smooth and rectify a voltage induced to the secondary winding of the transformer;
- a feedback unit configured to output a signal according to the voltage smoothed and rectified by the smoothing and rectifying unit;
- a control unit configured to control an operation of the first switching element and the second switching element based on the signal output from the feedback unit so that the voltage smoothed and rectified by the smoothing and rectifying unit becomes a predetermined voltage, the control unit configured to implement a control operation in a first voltage state, in which the predetermined voltage is a first voltage, and in a second voltage state, in which the predetermined voltage is a second voltage larger than the first voltage;
- and
- a notification unit configured to notify the control unit of switching between the first voltage state and the second voltage state,
- wherein the control unit is configured to perform one of the following:
- when the notification unit notifies switching from the first voltage state to the second voltage state, the control unit changes a condition to a first switching condition of performing control of gradually increasing a turn-on duty of the first switching element, and changes a voltage state to the second voltage state after a level of the signal output from the feedback unit reaches a first value or less, and when the notification unit notifies switching from the second voltage state to the first voltage state, the control unit changes a condition to a second switching condition of performing control of gradually decreasing the turn-on duty of the first switching element, and changes a voltage state to the first voltage state after the level of the signal output from the feedback unit reaches a second value or more;
- and
- when the notification unit notifies switching from the first voltage state to the second voltage state, the control unit changes a condition to the first switching condition of performing control of gradually increasing the turn-on duty of the first switching element, and changes a voltage state to the second voltage state after the level of the signal output from the feedback unit reaches the first value or more, and when the notification unit notifies switching from the second voltage state to the first voltage state, the control unit changes a condition to the second switching condition of performing control of gradually decreasing the turn-on duty of the first switching element, and changes a voltage state to the first voltage state after the level of the signal output from the feedback unit reaches the second value or less.
10 more elements
An image forming apparatus comprising:
- an image forming unit configured to form an image;
- and
- a power supply apparatus configured to supply electric power to the image forming apparatus,
- the power supply apparatus including:
- a transformer including a primary winding and a secondary winding;
- a first switching element connected in series to the primary winding of the transformer;
- a second switching element connected in parallel to the primary winding of the transformer;
- a capacitor connected in series to the second switching element, and is connected in parallel to the primary winding of the transformer together with the second switching element;
- a smoothing and rectifying unit configured to smooth and rectify a voltage induced to the secondary winding of the transformer;
- a feedback unit configured to output a signal according to the voltage smoothed and rectified by the smoothing and rectifying unit;
- a control unit configured to control an operation of the first switching element and the second switching element based on the signal output from the feedback unit so that the voltage smoothed and rectified by the smoothing and rectifying unit becomes a predetermined voltage, the control unit configured to implement a control operation in a first voltage state, in which the predetermined voltage is a first voltage, and in a second voltage state, in which the predetermined voltage is a second voltage larger than the first voltage;
- and
- a notification unit, which is configured to notify the control unit of switching between the first voltage state and the second voltage state,
- wherein the control unit is configured to perform one of the following:
- when the notification unit notifies switching from the first voltage state to the second voltage state, the control unit changes a condition to a first switching condition of performing control of gradually increasing a turn-on duty of the first switching element, and changes a voltage state to the second voltage state after a level of the signal output from the feedback unit reaches a first value or less, and when the notification unit notifies switching from the second voltage state to the first voltage state, the control unit changes a voltage state to a second switching condition of performing control of gradually decreasing the turn-on duty of the first switching element, and changes a voltage state to the first voltage state after the level of the signal output from the feedback unit reaches a second value or more;
- and
- when the notification unit notifies switching from the first voltage state to the second voltage state, the control unit changes a condition to the first switching condition of performing control of gradually increasing the turn-on duty of the first switching element, and changes a voltage state to the second voltage state after the level of the signal output from the feedback unit reaches the first value or more, and when the notification unit notifies switching from the second voltage state to the first voltage state, the control unit changes a condition to the second switching condition of performing control of gradually decreasing the turn-on duty of the first switching element, and changes a voltage state to the first voltage state after the level of the signal output from the feedback unit reaches the second value or less.
14 more elements
A power supply apparatus employing an active clamp system, comprising:
- a transformer including a primary winding and a secondary winding;
- a first switching element connected in series to the primary winding of the transformer;
- a second switching element connected in parallel to the primary winding of the transformer;
- a capacitor for voltage clamping, the capacitor connected in series to the second switching element, and connected in parallel to the primary winding of the transformer together with the second switching element;
- a smoothing and rectifying unit configured to smooth and rectify a voltage induced to the secondary winding of the transformer;
- a feedback unit configured to output a signal according to the voltage smoothed and rectified by the smoothing and rectifying unit;
- and
- a control unit configured to control an operation of the first switching element and the second switching element based on the signal output from the feedback unit so that the voltage smoothed and rectified by the smoothing and rectifying unit is a predetermined voltage,
- wherein the control unit is configured to implement a control operation in a first voltage state, in which the predetermined voltage is a first voltage, and in a second voltage state, in which the predetermined voltage is a second voltage larger than the first voltage,
- wherein the control unit is configured to perform control of gradually increasing a turn-on duty of the first switching element in a case where the first voltage state is switched to the second voltage state, and
- wherein the control unit is configured to perform control of gradually decreasing the turn-on duty of the first switching element in a case where the second voltage state is switched to the first voltage state.
8 more elements
An image forming apparatus comprising:
- an image forming unit configured to form an image;
- and
- a power supply apparatus employing an active clamp system, the power supply apparatus configured to supply electric power to the image forming apparatus,
- the power supply apparatus including:
- a transformer including a primary winding and a secondary winding;
- a first switching element connected in series to the primary winding of the transformer;
- a second switching element connected in parallel to the primary winding of the transformer;
- a capacitor for voltage clamping, the capacitor connected in series to the second switching element, and connected in parallel to the primary winding of the transformer together with the second switching element;
- a smoothing and rectifying unit configured to smooth and rectify a voltage induced to the secondary winding of the transformer;
- a feedback unit configured to output a signal according to the voltage smoothed and rectified by the smoothing and rectifying unit;
- and
- a control unit configured to control an operation of the first switching element and the second switching element the first switching element and the second switching element based on the signal output from the feedback unit so that the voltage smoothed and rectified by the smoothing and rectifying unit is a predetermined voltage,
- wherein the control unit is configured to implement a control operation in a first voltage state, in which the predetermined voltage is a first voltage, and in a second voltage state, in which the predetermined voltage is a second voltage larger than the first voltage,
- wherein the control unit is configured to perform control of gradually increasing a turn-on duty of the first switching element in a case where the first voltage state is switched to the second voltage state, and
- wherein the control unit is configured to perform control of gradually decreasing the turn-on duty of the first switching element in a case where the second voltage state is switched to the first voltage state.
12 more elements
Dependencies are inferred from the claim text.