Image processing apparatus, image recording apparatus, controlling method for these apparatuses, and power supply apparatus used therein

• US 6,408,148 B1
• Filed: 05/12/2000
• Issued: 06/18/2002
• Est. Priority Date: 05/17/1999
• Status: Expired due to Fees

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Yamamoto, Kazuma
• Primary Examiner(s): Chen, Sophia S.
• Application Number:
  US09/570,689
• Time in Patent Office: 767 Days
• Field of Search: 399/37, 399/68, 399/70, 399/88, 219/216, 323/282, 307/38, 307/139, 307/140
• US Class Current: 399/88
• CPC Class Codes: G03G 15/5004 Power supply control, e.g. power-saving mode, automatic power turn-off
• CPC Class Codes: H02M 1/0032 Control circuits allowing low power mode operation, e.g. in standby mode
• CPC Class Codes: H02M 1/0077 Plural converter units whose outputs are connected in series
• CPC Class Codes: H02M 1/008 Plural converter units for generating at two or more independent and non-parallel outputs, e.g. systems with plural point of load switching regulators
• CPC Class Codes: H02M 3/33523 with galvanic isolation between input and output of both the power stage and the feedback loop
• CPC Class Codes: Y02B 70/10 Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes

Abstract

An apparatus having a power supply section capable of outputting plural power supply voltages is provided with a sleep mode (energy-saving mode) for inhibiting at least one of the outputs from the power supply section in a wait state. Furthermore, an image forming apparatus such a printer is provided with a cut-off function for inhibiting at least one of the outputs from the power supply section supplied to a heater of a fixing device if an abnormality is detected, so that by relating the operation of this cut-off function and the operation of inhibiting at least one output at the power supply section to each other, these operations may be more easily controlled and also the number of components required can be reached.

Claims

1. An apparatus comprising:

DC power supply means for generating plural DC voltages from a power supplied from an AC power source, said DC power supply means comprising at least one transformer;

a load different from said DC power supply means, which is supplied with a power from the AC power source;

cutting-off means for cutting off the supply of power at least to the load from the AC power source in accordance with a control signal, the control signal being electrically separated from a primary side of said transformer; and

main control means for outputting the control signal to said cutting-off means,

wherein, when said cutting-off means is in a cut-off state, one output of the plural DC voltages is stopped without providing means, other than said cutting-off means, for electrically separating the control signal from the primary side of said transformer.

2. An apparatus according to claim 1, wherein

said DC power supply means has first means for generating a first DC power supply voltage and second means for generating a second DC power supply voltage, and

said cutting-off means cuts off the supply of power to both said load and said first means.

3. An apparatus according to claim 1, wherein said power supply means has first means for generating a first DC power supply voltage and second means for generating a second DC power supply voltage, and said apparatus comprises first and second controlling means for controlling said first and second means,

wherein the first DC power supply voltage is stopped according to an operating state of said cutting-off means.

4. An apparatus according to claim 3, wherein said first controlling means is supplied with power via a power supply line cut off by said cutting-off means, so that the first DC power supply voltage is stopped when said cutting-off means is in the cut-off state.

5. An apparatus according to claim 1, wherein said DC power supply means has at least one controlling means for controlling a primary side of said transformer at a predetermined frequency in such a way that at least one of the plural DC voltages generated by said DC power supply means may be equal to a predetermined voltage in a conducting state of said cutting-off means.

6. An apparatus according to claim 1, wherein

said DC power supply means comprises plural transformers and controlling means for controlling a primary side of said transformers at a predetermined frequency in such a way that the plural DC voltages generated by said DC power supply means may be equal to predetermined voltages respectively in a conducting state of said cutting-off means.

7. An apparatus according to claim 1, wherein said DC power supply means has a transformer and controlling means for controlling a primary side of the transformer at a predetermined frequency in such a way that one of the plural DC voltages generated by said DC power supply means may be equal to a first predetermined voltage in a conducting state of said cutting-off means, and said controlling means is controlled by a signal via a power supply line cut off by said cutting-off means.

8. An apparatus according to claim 7, wherein said transformer has first and second secondary windings, and generates first and second DC voltages by respectively rectifying outputs of said first and second secondary windings.

9. An apparatus according to claim 8, further comprising a regulator for regulating the first DC voltage to approximately the value of the second DC voltage,

wherein, on the basis of the signal via a power supply line cut off by said cutting-off means, said controlling means intermittently drives a primary side of said transformer in such a way that one of the plural DC voltages generated by said DC power supply means may be equal to a second predetermined voltage in a cut-off state of said cutting-off means, so that the output obtained by rectifying said first secondary winding is supplied as the second DC voltage via said regulator in a cut-off state of said cutting-off means.

10. An apparatus according to claim 9, further comprising specifying means for specifying either said first predetermined voltage or said second predetermined voltage on the basis of the control signal or another control signal output by said main control means.

11. An apparatus according to claim 1, wherein said apparatus is an image recording apparatus for forming a toner image on a recording medium in an electrostatic recording method, and said load is a fixation heater for fixing the formed toner image onto the recording medium.

12. An apparatus according to claim 11, wherein said DC power supply means comprises first means for generating a first DC power supply voltage and second means for generating a second DC power supply voltage, and said cutting-off means cuts off the supply of power to both said load and said first means.

13. An apparatus according to claim 11, wherein said power supply means has first means for generating a first DC power supply voltage and second means for generating a second DC power supply voltage, and said apparatus comprises first and second controlling means for controlling said first and second means,

wherein the first DC power supply voltage is stopped according to an operating state of said cutting-off means.

14. An apparatus according to claim 13, wherein said first controlling means is supplied with power via a power supply line cut off by said cutting-off means, so that the first DC power supply voltage is stopped when said cutting-off means is in the cut-off state.

15. An apparatus according to claim 11, wherein said DC power supply means has at least one controlling means for controlling a primary side of said transformer at a predetermined frequency in such a way that at least one of the plural DC voltages generated by said DC power supply means may be equal to a predetermined voltage in a conducting state of said cutting-off means.

16. An apparatus according to claim 11, wherein said DC power supply means has plural transformers and plural controlling means, each of the plural controlling means controls a primary side of a corresponding transformer at a predetermined frequency in such a way that the plural DC voltages generated by said DC power supply means may be equal to predetermined voltages, respectively, in a conducting state of said cutting-off means.

17. An apparatus according to claim 11, wherein said DC power supply means has controlling means for controlling a primary side of said transformer at a predetermined frequency in such a way that one of the plural DC voltages generated by said DC power supply means may be equal to a first predetermined voltage in a conducting state of said cutting-off means, and said controlling means is controlled by a signal via a power supply line cut off by said cutting-off means.

18. An apparatus according to claim 17, wherein said transformer has first and second secondary windings, and generates first and second DC voltages by respectively rectifying outputs of said first and second secondary windings.

19. An apparatus according to claim 18, further comprising a regulator for regulating the first DC voltage to approximately the value of the second DC voltage,

wherein, on the basis of the signal via a power supply line cut off by said cutting-off means, said controlling means intermittently drives a primary side of said transformer in such a way that one of the plural DC voltages generated by said DC power supply means may be equal to a second predetermined voltage in a cut-off state of said cutting-off means, so that the output obtained by rectifying said first secondary winding is supplied as the second DC voltage via said regulator in a cut-off state of said cutting-off means.

20. An apparatus according to claim 19, further comprising specifying means for specifying either the first predetermined voltage or the second predetermined voltage on the basis of the control signal or another control signal output by said main control means.