Power supply apparatus and image forming apparatus

{
  "publication_number": "US10944327B2",
  "country": "US",
  "kind": "B2",
  "title": "Power supply apparatus and image forming apparatus",
  "abstract": "The power supply apparatus includes a rectifying and smoothing unit configured to rectify and smooth an AC voltage of an AC power supply, a transformer having a primary winding, first and second secondary windings, a detecting unit connected to the second secondary winding, the detecting unit configured to detect a second voltage according to a voltage output from the rectifying and smoothing unit, and a first control unit configured to control a state of the load based on a result detected by the detecting unit.",
  "claims": [
    "1. A power supply apparatus comprising: a rectifying and smoothing unit configured to rectify and smooth an AC voltage of an AC power supply; a transformer having a primary winding, a first secondary winding and a second secondary winding connected to the first secondary winding through a signal line, the transformer configured to convert a voltage output from the rectifying and smoothing unit to output a first voltage to be supplied to a load; a detecting unit connected to the signal line between the first secondary winding and the second secondary winding, the detecting unit configured to detect a second voltage according to a voltage output from the rectifying and smoothing unit; and a first control unit configured to control a state of the load based on a result detected by the detecting unit.",
    "2. The power supply apparatus according to claim 1, comprising a memory unit configured to store information in which the AC voltage or a voltage output from the rectifying and smoothing unit and a state of the load are associated with the AC voltage or the voltage, wherein the first control unit controls a state of the load based on the result detected by the detecting unit and the information stored in the memory unit.",
    "3. The power supply apparatus according to claim 1, comprising: a switching element connected to the primary winding; a second control unit configured to control a switching operation of the switching element; and a feedback unit configured to feed back a voltage according to the first voltage to the second control unit.",
    "4. The power supply apparatus according to claim 3, wherein based on the result detected by the detecting unit, the first control unit performs control to shift a state of the load to any one state among a first state in which the power supply apparatus is stopped, a second state in which the power supply apparatus is operating and the load is stopped, a third state in which power consumed by the load is greater than power in the second state, and a fourth state in which power consumed by the load is greater than power in the third state.",
    "5. The power supply apparatus according to claim 4, wherein the first control unit: performs control to shift a state of the load to the first state in a case where a voltage detected by the detecting unit is less than a first threshold voltage; performs control to shift a state of the load to the second state in a case where a voltage detected by the detecting unit is greater than the first threshold voltage and less than a second threshold voltage; performs control to shift a state of the load to the third state in a case where a voltage detected by the detecting unit is greater than the second threshold voltage and less than a third threshold voltage; and performs control to shift a state of the load to the fourth state in a case where a voltage detected by the detecting unit is greater than the third threshold voltage.",
    "6. An image forming apparatus configured to form an image on a recording medium, the image forming apparatus having a power supply apparatus configured to supply power to the image forming apparatus, wherein the power supply apparatus comprises: a rectifying and smoothing unit configured to rectify and smooth an AC voltage of an AC power supply; a transformer having a primary winding, a first secondary winding and a second secondary winding connected to the first secondary winding through a signal line, the transformer configured to convert a voltage output from the rectifying and smoothing unit to output a first voltage to be supplied to a load; a detecting unit connected to the signal line between the first secondary winding and the second secondary winding, the detecting unit configured to detect a second voltage according to a voltage output from the rectifying and smoothing unit; and a first control unit configured to control a state of the load based on a result detected by the detecting unit.",
    "7. The image forming apparatus according to claim 6, comprising a memory unit configured to store information in which the AC voltage or a voltage output from the rectifying and smoothing unit and a state of the load are associated with the AC voltage or the voltage, wherein the first control unit controls a state of the load based on the result detected by the detecting unit and the information stored in the memory unit.",
    "8. The image forming apparatus according to claim 6, comprising: a switching element connected to the primary winding; a second control unit configured to control a switching operation of the switching element; and a feedback unit configured to feed back a voltage according to the first voltage to the second control unit.",
    "9. The image forming apparatus according to claim 8, wherein based on the result detected by the detecting unit, the first control unit performs control to shift a state of the load to any one state among a first state in which the power supply apparatus is stopped, a second state in which the power supply apparatus is operating and the load is stopped, a third state in which power consumed by the load is greater than power in the second state, and a fourth state in which power consumed by the load is greater than power in the third state.",
    "10. The image forming apparatus according to claim 9, wherein the first control unit: performs control to shift a state of the load to the first state in a case where a voltage detected by the detecting unit is less than a first threshold voltage; performs control to shift a state of the load to the second state in a case where a voltage detected by the detecting unit is greater than the first threshold voltage and less than a second threshold voltage; performs control to shift a state of the load to the third state in a case where a voltage detected by the detecting unit is greater than the second threshold voltage and less than a third threshold voltage; and performs control to shift a state of the load to the fourth state in a case where a voltage detected by the detecting unit is greater than the third threshold voltage.",
    "11. The image forming apparatus according to claim 10, wherein the third state is a state in which the image forming apparatus stands by for input of print data, and wherein the fourth state is a state in which it is possible to perform image forming operations.",
    "12. The image forming apparatus according to claim 9, wherein the third state is a state in which the image forming apparatus stands by for input of print data, and wherein the fourth state is a state in which image forming operations are enabled.",
    "13. A power supply apparatus comprising: a rectifying and smoothing unit configured to rectify and smooth an AC voltage of an AC power supply; a transformer having a primary winding, a first secondary winding and a second secondary winding, the first secondary winding configured to convert a voltage output from the rectifying and smoothing unit to output a first voltage to be supplied to a load and the second secondary winding configured to convert the output from the rectifying and smoothing unit to output a second voltage; a detecting unit connected to the second secondary winding, the detecting unit configured to detect the second voltage; and a first control unit configured to control a state of the load based on a result detected by the detecting unit.",
    "14. An image forming apparatus configured to form an image on a recording medium, the image forming apparatus having a power supply apparatus configured to supply power to the image forming apparatus, wherein the power supply apparatus comprises: a rectifying and smoothing unit configured to rectify and smooth an AC voltage of an AC power supply; a transformer having a primary winding, a first secondary winding and a second secondary winding, the first secondary winding configured to convert a voltage output from the rectifying and smoothing unit to output a first voltage to be supplied to a load and the second secondary winding configured to convert the output from the rectifying and smoothing unit to output a second voltage; a detecting unit connected to the second secondary winding, the detecting unit configured to detect the second voltage; and a first control unit configured to control a state of the load based on a result detected by the detecting unit."
  ],
  "description_excerpt": "The present invention relates to a power supply apparatus and an image forming apparatus, and more particularly relates to a power supply apparatus that rectifies and smoothes an AC voltage input from an AC power supply and generates a DC voltage by a switching element and a transformer.\n\nSome power supply apparatuses and image forming apparatuses are configured to support a power supply turn-off state in which power consumption is extremely small while receiving a supply of power from an AC power supply, a stand-by state which corresponds to a low load during standby operation, and a high load operating state in which the power consumption is greater than in the stand-by state. In addition, a configuration is also available that controls the operation of a power supply apparatus by rectifying and smoothing an input voltage from an AC power supply and detecting the voltage, and providing a monitoring control circuit that monitors an input voltage using an optical semiconductor (see Japanese Patent Application Laid-Open No. H08-182315).\n\nHowever, because power is consumed when a voltage that was rectified and smoothed is detected and a light emitting device of an optical semiconductor is driven, it has conventionally been difficult to achieve power savings. Further, in a case where operation of a power supply is stopped to protect the power supply in a state in which the input voltage is low, shifting to a low load state in which operation is enabled even in a state in which the input voltage is low cannot be performed, and the power supply to a load which consumes power connected to the power supply apparatus is cut off.",
  "cpc": [
    "H02M 3/33523",
    "G03G 15/5004",
    "G03G 15/80",
    "H02M 1/0032",
    "H02M 3/28",
    "H02M 7/04",
    "H02M 7/2176",
    "Y02B 70/10"
  ],
  "ipc": [
    "G03G 15/00",
    "H02M 3/335"
  ],
  "assignees": [
    "Canon Inc"
  ],
  "inventors": [
    "Mitsuhide Murofushi"
  ],
  "filing_date": "2020-05-07",
  "publication_date": "2021-03-09",
  "grant_date": "2021-03-09",
  "priority_date": "2019-05-16",
  "application_number": "US-202016868879-A",
  "family_id": "73223292",
  "cited_by_count": 3,
  "citations": [
    "US5285368A",
    "JPH08182315A",
    "US8085560B2",
    "US8830703B2",
    "US20110158674A1",
    "JP2017041949A",
    "US20180026524A1",
    "US10277764B2"
  ]
}