POWER SUPPLY APPARATUS AND IMAGE FORMING APPARATUS

• US 20140198337A1
• Filed: 01/06/2014
• Published: 07/17/2014
• Est. Priority Date: 01/17/2013
• Status: Active Grant

• Current Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Original Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Inventors: Nakajima, Nozomu, Kawazu, Takao
• Granted Patent: US 9,171,241 B2
• Time in Patent Office: Days
• US Class Current: 358/1.14
• CPC Class Codes: G03G 15/5004 Power supply control, e.g. power-saving mode, automatic power turn-off
• CPC Class Codes: G03G 15/80 Details relating to power supplies, circuits boards, electrical connections
• CPC Class Codes: G06K 15/4055 Managing power consumption, e.g. standby mode computer driven power saving management for a printer G06F3/1221; power saving in a data processing device in general G06F1/32
• CPC Class Codes: H02H 3/20 responsive to excess voltage

Abstract

The power supply apparatus includes a first power supply unit for outputting a first voltage; a second power supply unit for outputting a second voltage different from the first voltage; a switch unit operating with the first voltage, which is disposed in a power supply path connecting to the second power supply unit, for supplying and shutting down power to the second power supply unit; a detection unit for detecting that a predetermined voltage or higher is supplied to the first power supply unit; and a control unit for controlling the switch unit to stop the output of the first voltage from the first power supply unit, when the detection unit detects that the predetermined voltage or higher is supplied to the first power supply unit.

Claims

1. A power supply apparatus, comprising:

a first power supply unit to which a power is supplied from an AC power source, for outputting a first voltage;

a second power supply unit to which a power is supplied from an AC power source, for outputting a second voltage different from the first voltage;

a switch unit which operates with the first voltage from the first power supply unit, and is disposed in a power supply path from the AC power source to the second power supply unit so as to perform power supply and cut-off of the power to the second power supply unit;

a detection unit for detecting that a predetermined voltage or higher is supplied from the AC power source to the first power supply unit; and

a control unit for controlling the switch unit to stop the output of the first voltage from the first power supply unit so as to cut off the power supply to the second power supply unit, when the detection unit detects that the predetermined voltage or higher is supplied to the first power supply unit.

2. A power supply apparatus according to claim 1, wherein the control unit controls the switch unit to stop the output of the first voltage from the first power supply unit until the power supply from the AC power source is stopped, to thereby cut off the power supply to the second power supply unit, when the detection unit detects that the predetermined voltage or higher is supplied to the first power supply unit.

3. A power supply apparatus according to claim 1, wherein the detection unit operates to consume power when the voltage supplied from the AC power source to the first power supply unit is the predetermined voltage or higher.

4. A power supply apparatus according to claim 1, wherein the detection unit includes a constant voltage element.

5. A power supply apparatus according to claim 1, wherein in a case where V1 represents a withstanding voltage of a rectification capacitor disposed in the first power supply unit for smoothing the input voltage from the AC power source, V2 represents a withstanding voltage of a rectification capacitor disposed in the second power supply unit for smoothing the input voltage from the AC power source, V3 represents the predetermined voltage of the input voltage to be detected by the detection unit, and V4 represents a peak value of a voltage of the AC power source, the power supply apparatus satisfies a relationship:

V1>

V2>

V3>

V4.

6. A power supply apparatus according to claim 5,

wherein the second power supply unit comprises multiple second power supply units, and

wherein the withstanding voltage V2 is a lowest withstanding voltage among the withstanding voltages of the rectification capacitors disposed in the multiple second power supply units.

7. A power supply apparatus according to claim 6, wherein in a case where V3 is more than V2, Va representing a voltage at which the rectification capacitor opens a valve after a predetermined time period is more than V3.

8. A power supply apparatus according to claim 5, wherein the rectification capacitor includes an aluminum electrolytic capacitor.

9. A power supply apparatus, comprising:

a first power supply unit to which a power is supplied from an AC power source, for outputting a first voltage;

a second power supply unit to which a power is supplied from an AC power source, for outputting a second voltage different from the first voltage;

a switch unit which operates with the first voltage from the first power supply unit, and is disposed in a power supply path from the AC power source to the second power supply unit, so as to perform power supply and cut-off of the power to the second power supply unit;

a detection unit for detecting that a predetermined voltage or higher is supplied from the AC power source to the second power supply unit; and

a control unit for controlling the switch unit to stop the output of the first voltage from the first power supply unit and the output of the second voltage from the second power supply unit so as to cut off the power supply to the second power supply unit, when the detection unit detects that the predetermined voltage or higher is supplied to the second power supply unit.

10. A power supply apparatus according to claim 9, wherein the control unit controls the switch unit to stop the output of the first voltage from the first power supply unit and the output of the second voltage from the second power supply unit until the power supply from the AC power source is stopped, to thereby cut off the power supply to the second power supply unit.

11. A power supply apparatus according to claim 9, wherein in a case where V1 represents a withstanding voltage of a rectification capacitor disposed in the first power supply unit for smoothing the input voltage from the AC power source, V2 represents a withstanding voltage of a rectification capacitor disposed in the second power supply unit for smoothing the input voltage from the AC power source, V3 represents the predetermined voltage of the input voltage to be detected by the detection unit, and V4 represents a peak value of a voltage of the AC power source, the power supply apparatus satisfies a relationship:

V1>

V2>

V3>

V4.

12. A power supply apparatus according to claim 9, wherein the second power supply unit comprises multiple second power supply units, and

wherein the withstanding voltage V2 is a lowest withstanding voltage among the withstanding voltages of the rectification capacitors disposed in the multiple second power supply units.

13. A power supply apparatus according to claim 9, wherein in a case where V3 is more than V2, Va representing a voltage at which the rectification capacitor opens a valve after a predetermined time period is more than V3.

14. A power supply apparatus according to claim 13, wherein the rectification capacitor includes an aluminum electrolytic capacitor.

15. An image forming apparatus, comprising:

an image forming unit for forming an image on a sheet; and

a power supply for supplying power for operating the image forming apparatus, the power supply comprising;

a first power supply unit supplied with power from an AC power source so as to output a first voltage;

a second power supply unit supplied with power from the AC power source so as to output a second voltage different from the first voltage;

a switch unit which operates with the first voltage from the first power supply unit, and is disposed in a power supply path from the AC power source to the second power supply unit, so as to perform power supply and cut-off of the power to the second power supply unit;

a detection unit for detecting that a predetermined voltage or higher is supplied from the AC power source to the first power supply unit; and

a control unit for controlling the switch unit to stop the output of the first voltage from the first power supply unit so as to cut off the power supply to the second power supply unit, when the detection unit detects that the predetermined voltage or higher is supplied to the first power supply unit.

16. An image forming apparatus according to claim 15, further comprising a controller for controlling the image forming unit,

wherein the power supply supplies power to the controller.

17. An image forming apparatus, comprising:

an image forming unit for forming an image on a sheet; and

a power supply for supplying power for operating the image forming apparatus, the power supply comprising;

a first power supply unit supplied with power from an AC power source so as to output a first voltage;

a second power supply unit supplied with power from the AC power source so as to output a second voltage different from the first voltage;

a switch unit which operates with the first voltage from the first power supply unit, and is disposed in a power supply path from the AC power source to the second power supply unit, so as to perform power supply and cut-off of the power to the second power supply unit;

a detection unit for detecting that a predetermined voltage or higher is supplied from the AC power source to the second power supply unit; and

a control unit for controlling the switch unit to stop the output of the first voltage from the first power supply unit and the output of the second voltage from the second power supply unit, to thereby cut off the power supply to the second power supply unit, when the detection unit detects that the predetermined voltage or higher is supplied to the second power supply unit.

18. An image forming apparatus according to claim 17, further comprising a controller for controlling the image forming unit,

wherein the power supply supplies power to the controller.