JP4948937B2 - Image forming apparatus - Google Patents

Description

 The present invention relates to an image forming apparatus.

  As an apparatus for forming an image by fixing toner on a recording medium such as paper, there is an image forming apparatus such as a printer, a copying machine, a facsimile, or a multifunction machine in which the functions of these devices are combined. The fixing device provided in the image forming apparatus mainly includes a fixing roller and a heating unit. The fixing roller is a pair of rollers facing each other in a state where the peripheral surfaces are in close contact with each other, and the heating unit heats a fixing roller (heating roller) located on the toner side of the recording medium among the pair of fixing rollers. Is. The fixing device configured in this manner fixes the toner image transferred onto the recording medium by the photosensitive member to the recording medium by pressing and heating the recording medium passing between the pair of fixing rollers.

    In the above fixing device, the heating unit includes a main heating element (main heater) and an auxiliary heating element (auxiliary heater), a main power supply device that supplies electric power to the main heater, and electric power (auxiliary power) to the auxiliary heater. ) And an auxiliary power supply device using a power storage device (for example, an electric double layer capacitor) as a power source. At the time of starting up such a fixing device, in addition to supplying power from the main power supply device to the main heater, by supplying power from the auxiliary power supply device to the auxiliary heater and heating the heating roller, the fixing device can be quickly started up. Raise. For example, Patent Document 1 below discloses a fixing device including such an auxiliary power supply device and an image forming apparatus including the fixing device.

In addition, it is known that the above-described power storage device has a short life when held in a fully charged state for a long time. In Patent Document 2 below, the image forming apparatus is in an energy saving mode, the temperature of the fixing roller is higher than room temperature, and it is not necessary to supply power from the power storage device to the auxiliary heater. In this case, a technique for extending the life of the power storage device by lowering the charging voltage of the power storage device by, for example, 0.1 V / cell is disclosed.
JP 2000-315567 A JP 2004-303518 A

    However, according to the technique of Patent Document 2, the configuration of the charging circuit and the charging control are complicated, and there is a problem that the device cost increases.

  The present invention has been made in view of the above-described circumstances, and an object thereof is to extend the life of a power storage device provided in an auxiliary power supply device while suppressing an increase in device cost.

  In order to achieve the above object, the present invention provides a main power supply device, a main heating element to which power is supplied from the main power supply device, and a predetermined power storage device as a first solving means for the image forming apparatus. An image forming apparatus comprising: an auxiliary power supply as a source; and an auxiliary heating element to which electric power is supplied from the auxiliary power supply apparatus, wherein the fixing roller is heated by the main heating element and the auxiliary heating element. Power supply switching means for selectively outputting one of the power supplied from the power supply device and the power supplied from the auxiliary power supply device as power supply power for internal devices excluding the main heating element and the auxiliary heating element; And a control means for performing switching control of power supply power in the power supply switching means in accordance with the use situation.

    Further, as a second solving means relating to the image forming apparatus, in the first solving means, the control means outputs the power supplied from the auxiliary power supply device during standby at night as the power supply power of the internal device. As described above, the switching control of the power source switching means is performed.

    Further, as a third solving means relating to the image forming apparatus, in the first or second solving means, the control means does not give an operation instruction from the outside even if a predetermined time elapses after shifting to the sleep mode. In this case, switching control of the power source switching unit is performed so that power supplied from the auxiliary power device is output as power source power of the internal device.

Further, as a fourth solving means relating to the image forming apparatus, in any of the first to third solving means, a DC voltage conversion circuit is provided between the auxiliary power supply device and the power supply switching means,
The DC voltage conversion circuit converts the DC voltage supplied from the auxiliary power supply device so as to match the power supply voltage of the internal device.

    Further, as a fifth solving means relating to the image forming apparatus, in any one of the first to fourth solving means, the control means performs switching control of power supply power in the power supply switching means according to a use situation. A first mode; and a second mode for performing switching control of the power source switching unit so that power supplied from the main power supply device is output as power source power of the internal device regardless of usage conditions. And

  According to the present invention, either the power supplied from the main power supply device or the power supplied from the auxiliary power supply device is selectively selected according to the use state of the image forming apparatus, and the main heating element and the auxiliary power supply are selectively used. Used as power supply for internal equipment excluding heating elements. In other words, during periods when it is not necessary to heat the fixing roller, such as during nighttime standby, the state where the charging voltage of the power storage device is kept as low as possible by using the power supplied from the auxiliary power supply device as the power supply power for the internal devices. As a result, the life of the power storage device can be extended. Further, since it is only necessary to provide a power supply switching means such as a switch as compared with the conventional case, an increase in apparatus cost can be suppressed.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram illustrating a functional configuration of the image forming apparatus according to the present embodiment. The image forming apparatus according to the present exemplary embodiment will be described by exemplifying a multifunction peripheral having a plurality of functions such as a printing machine, a copying machine, and a facsimile.

  As shown in FIG. 1, the image forming apparatus includes a power supply device 1 (main power supply device), a power supply monitoring circuit 2, a power supply control unit 3, a charge control circuit 4, a power storage device 5, a discharge control circuit 6, an engine system 7, It comprises a power system switch 8 (power switching means), a dehumidifying heater 9, a cooling fan 10, and a multifunction machine controller 11. The engine system 7 includes a fixing heater 7a (main heating element) and an auxiliary fixing heater 7b (auxiliary heating element), and the multifunction machine controller 11 includes a CPU (Central Processing Unit) 11a, a storage unit 11b, and a facsimile control unit. 11c. Of the above components, the charge control circuit 4, the power storage device 5, and the discharge control circuit 6 constitute an auxiliary power supply device, and the CPU 11a and the power supply control unit 3 constitute a control means.

  The power supply device 1 outputs AC 100 V commercial power supplied from the outside to one input terminal of the charge control circuit 4, the fixing heater 7 a, and the power system switching switch 8. The power supply monitoring circuit 2 monitors the voltage value of AC100V commercial power (hereinafter referred to as main power) output from the power supply device 1 and outputs the monitoring result to the power supply control unit 3. The power supply control unit 3 is driven by auxiliary power supplied from the discharge control circuit 6, and based on the control signal input from the CPU 11 a and the monitoring result of the main power input from the power supply monitoring circuit 2, the power supply system changeover switch 8 is controlled.

  Charging control circuit 4 is for charging power storage device 5, rectifies main power, which is AC power, to convert it into DC power, and outputs the DC power to power storage device 5. The power storage device 5 is composed of, for example, one electric double layer capacitor or a plurality of electric double layer capacitors connected in series, and charges the electric double layer capacitor with the DC power as a charge, while the electric double layer capacitor includes The charged electric charge is output to the discharge control circuit 6 as a discharge current. The discharge control circuit 6 controls the discharge of charges from the power storage device 5. The power control unit 3, the auxiliary fixing heater 7 b, and the power system switching switch 8 use the charge stored in the power storage device 5 as auxiliary power. Output to the other input terminal.

  The fixing heater 7 a is an AC halogen heater provided in one of a pair of fixing rollers (not shown), and generates heat when AC 100 V (main power) that is AC power is supplied from the power supply device 1. The auxiliary fixing heater 7b is a DC halogen heater provided in the same fixing roller as the fixing heater 7a, and generates heat when auxiliary power is supplied from the discharge control circuit 6. The pair of fixing rollers are rollers that face each other in a state where their peripheral surfaces are in close contact with each other, and fix the toner image on the recording medium by sandwiching the recording medium in a pressed state by rotating in opposite directions. It is what

  Under the control of the power supply control unit 3, the power supply system changeover switch 8 selectively selects either main power input from the power supply device 1 or auxiliary power input from the discharge control circuit 6. And output to the cooling fan 10 and the multi-function device controller 11. The dehumidifying heater 9 is a heater for performing dehumidification in the image forming apparatus, and is driven by main power or auxiliary power supplied via the power system switching switch 8. The cooling fan 10 is for keeping the temperature in the image forming apparatus constant, and is driven by main power or auxiliary power supplied via the power system switching switch 8.

  The multi-function device controller 11 is driven by main power or auxiliary power supplied via the power system switching switch 8 and controls the overall operation of the image forming apparatus. Specifically, the CPU 11a controls the power supply control unit 3 and the facsimile control unit 11c based on the control program and various control data stored in the storage unit 11b, and the engine system 7 (that is, the fixing heater 7a and the auxiliary heater 7a). ON / OFF control of the fixing heater 7b) is performed. The storage unit 11b includes, for example, a flash memory or an HDD, and stores a control program used by the CPU 11a, various control data, and the like. The facsimile control unit 11c performs control related to the facsimile function in the image forming apparatus under the control of the CPU 11a.

    Next, characteristic operations of the image forming apparatus configured as described above will be described in detail. In the initial state, the power supply system changeover switch 8 outputs the main power input from the power supply device 1 to the dehumidifying heater 9, the cooling fan 10, and the multifunction device controller 11.

    First, in a normal use time zone such as daytime, the CPU 11a controls the fixing heater 7a and the auxiliary fixing heater 7b to be in an ON state, feeds the main power from the power supply device 1 to the fixing heater 7a, and discharges. Auxiliary power is supplied from the control circuit 6 to the auxiliary fixing heater 7b. As a result, the temperature of the fixing roller is rapidly raised to the target temperature, and the fixing temperature is raised at an early stage. After completing the fixing start-up, the CPU 11a performs a printing process and other processes. When the fixing temperature is stabilized and the auxiliary fixing heater 7b is not required to be used, the CPU 11a controls the auxiliary fixing heater 7b to be in an OFF state, and the charging control circuit 4 performs the charging process of the power storage device 5 at a predetermined timing. I do. Here, the CPU 11a shifts to the sleep mode when the power storage device 5 is fully charged and there is no print instruction or user operation input from the external device even after a predetermined time has elapsed. Note that the dehumidifying heater 9, the cooling fan 10, and the multi-function device controller 11 are driven by the main power supplied from the power supply device 1 during the normal use time such as daytime.

  On the other hand, when the CPU 11a detects that it is nighttime, the CPU 11a controls the power system switching switch 8 through the power controller 3, and the auxiliary power input from the discharge control circuit 6 is used as the dehumidifying heater 9, the cooling fan 10, and the composite. Output to the machine controller 11. That is, the power supply system changeover switch 8 is switched so that the power consumption during standby at night is supplied from the power storage device 5. At night, the image forming apparatus is not used and shifts to the sleep mode, so that it is not necessary to supply power to the fixing heater 7a and the auxiliary fixing heater 7b. Therefore, the charging voltage of the power storage device 5 can be lowered by supplying the power consumption of the dehumidifying heater 9, the cooling fan 10, and the multifunction device controller 11 that are waiting at night from the power storage device 5 as described above. it can. As a result, the time for the power storage device 5 to be fully charged can be shortened, and the life of the power storage device 5 can be extended. Moreover, since it is only necessary to provide the power supply system changeover switch 8 as compared with the prior art, an increase in device cost can be suppressed.

  As a method for detecting that it is nighttime, the current time is monitored, and when the current time is, for example, 10 pm, it may be determined that it is nighttime. Even if the time (for example, about 2 hours) elapses, the case where there is no print instruction from the external device or user's operation input may be determined as night.

  Further, as described above, when the power consumption of the dehumidifying heater 9, the cooling fan 10 and the multifunction device controller 11 during the night and standby is supplied from the power storage device 5, the printing process is performed in the normal use time zone of the next day. For example, since the charging voltage of the power storage device 5 is lower than the voltage required for the auxiliary fixing heater 7b, the time for raising the temperature of the fixing roller becomes longer than that at the time of full charging, It becomes a factor giving discomfort.

  Therefore, for example, by operating the operation key of the image forming apparatus, the first mode in which the power consumption during standby at night is supplied from the power storage device 5 as described above, and the power source is also used at night as in the normal use time zone. By providing a function of switching from the device 1 to the second mode for supplying the standby power consumption, the life of the power storage device 5 is maintained even when the time for raising the temperature of the fixing roller is longer than that at the time of full charge. When priority is given to the user, the first mode is selected, and when the printing process or the like needs to be performed in a hurry, the second mode is selected to improve the usability of the user.

In addition, this invention is not limited to the said embodiment, For example, the following modifications can be considered.
(1) In the above embodiment, the dehumidifying heater 9, the cooling fan 10, and the multifunction device controller 11 have been described as examples of internal devices. However, the present invention is not limited thereto, and auxiliary power is supplied from the auxiliary power supply to other internal devices. You may supply.

(2) Further, since the power storage device 5 generally has a large charging voltage, a DC / DC converter (DC voltage conversion circuit) is provided between the discharge control circuit 6 and the power supply system changeover switch 8, A configuration is adopted in which the DC voltage supplied from the discharge control circuit 6 is converted by the DC / DC converter so as to conform to the power supply voltage of the internal devices (the dehumidifying heater 9, the cooling fan 10, and the multifunction device controller 11). May be.

1 is a block diagram illustrating a functional configuration of an image forming apparatus according to an embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Power supply device (main power supply device), 2 ... Power supply monitoring circuit, 3 ... Power supply control part, 4 ... Charge control circuit, 5 ... Power storage device, 6 ... Discharge control circuit, 7 ... Engine system, 8 ... Power supply system switch (Power source switching means), 9 ... dehumidifying heater, 10 ... cooling fan, 11 ... multifunction machine controller, 7a ... fixing heater (main heating element), 7b ... auxiliary fixing heater (auxiliary heating element), 11a ... CPU (Central Processing) Unit), 11b ... storage unit, 11c ... facsimile control unit

Claims (3)

A main power supply, a main heating element to which power is supplied from the main power supply, an auxiliary power supply using a predetermined power storage device as a power source, and an auxiliary heating element to which power is supplied from the auxiliary power supply An image forming apparatus for heating a fixing roller by the main heating element and the auxiliary heating element,
Power supply switching for selectively outputting one of the power supplied from the main power supply and the power supplied from the auxiliary power supply as the power supply for internal devices excluding the main heating element and the auxiliary heating element Means,
When the first mode is selected by operating the operation key, the switching control of the power supply switching means is performed so that the power supplied from the auxiliary power supply device is output as the power supply power of the internal device during the night standby. When the second mode is selected by operating the operation key, the power supply switching means is switched so that the power supplied from the main power supply device is always output as the power supply power of the internal device. An image forming apparatus comprising: a control unit that performs control. When the first mode is selected by operating the operation key , the control means determines that no operation instruction is given from the outside even if a predetermined time has elapsed after entering the sleep mode. the image forming apparatus according to claim 1, characterized in that the switching control of the power supply switching means as power supplied is outputted as the source power of the internal equipment from the auxiliary power unit. A DC voltage conversion circuit is provided between the auxiliary power supply and the power supply switching means,
3. The image forming apparatus according to claim 1, wherein the DC voltage conversion circuit converts a DC voltage supplied from an auxiliary power supply so as to match a power supply voltage of the internal device.

Images