JP4919324B2 - Image forming apparatus, power supply control method, and program - Google Patents

Description

  The present invention provides a user in an image forming mode, a standby mode, and an OFF / SLEEP mode, such as a copying machine, a printer, a facsimile, and an MFP (an apparatus having a combination of functions such as a copy, a printer, a scanner, and a facsimile). More specifically, it is possible to use a power source provided as a main power source and a sub power source for devices that require power supply in the OFF / SLEEP mode. It relates to power supply control.

In recent years, environmental problems have become important, and energy saving (power saving) is progressing also in apparatuses that perform image forming processing such as copiers and printers.
Among these types of apparatuses, particularly in an apparatus that performs an electrophotographic image forming operation, a large element of energy consumption is the power of a heater used when fixing toner onto a recording medium, which is an object of power saving. ing. In the OFF mode, SLEEP mode, or standby mode (maintained at a constant temperature slightly lower than the fixing temperature required for image forming operation), which has been adopted as an energy-saving mode from the past, Power saving is achieved by maintaining the temperature state.
In addition, when starting up from the temperature of the previous device state to the fixing temperature required for image forming operation, that is, when starting up from each power supply SW-ON, OFF, SLEEP, standby mode or recovery operation state, Early recovery is required in order to shorten the time required for startup so as to obtain a high power saving effect and not to make the user feel the waiting time.
Therefore, the power consumed during this early recovery is quite large. For this reason, there is an image forming apparatus in which a chargeable / dischargeable capacitor unit is provided in an image forming apparatus, and electric power charged in the capacitor is used as an auxiliary power source for a fixing heater when the temperature is raised to a fixing temperature. In addition, there is a system in which the voltage charged in the capacitor is used for power supply to other than the fixing unit of the image forming apparatus, so that a larger amount of power from the commercial power source can be used for the fixing heater.
As a document showing the prior art using the auxiliary power source as described above, an image forming apparatus described in Patent Document 1 below can be exemplified. This conventional example has a power storage device that stores the power supplied from the main power supply when there is a margin in power consumption, and the image forming apparatus has insufficient power or needs more power. In addition, a method has been proposed in which a DC power source from a power storage device is used as an auxiliary power source during both image forming operation and standby.

Similarly to Patent Document 1, FIG. 12 can be shown as a conventional example of a power supply circuit of an image forming apparatus using a power storage device that receives charge from a main power supply as a sub power supply.
In the circuit shown in FIG. 12, the power storage device 105 formed of a capacitor is exclusively used as a power source for driving the fixing DC heater 140. Charging / discharging the power storage device 105 is performed via the charger 107 and the DC / DC converter 108.
The charger 107 has a DC / DC converter (DDC) 106, and at the time of charging, the power supply 105 supplied from the power supply unit 127 which is a main power supply is matched with the rated voltage of the power storage device 105 made of a capacitor by this converter. Convert voltage. The power supply unit 127 is connected to a commercial AC power supply and can be constantly supplied with power.
The DC / DC converter 108 converts the voltages 121 and 122 charged in the charger 107 into a voltage 123 supplied to the fixing DC heater 140 at the time of discharging.
A power source 119 is supplied from the power source 127 to the electrical component 114 that requires constant power supply during the image forming operation and over the OFF, SLEEP, and standby modes. Examples of the electrical component 114 include a dehumidifying heater 131, an ADF document sensor 129 that generates a return signal by detecting an operation that causes a return from the OFF / SLEEP mode, a document set sensor 130, and the like.
The capacitor control unit 112 controls charging / discharging of the capacitor 105 at a predetermined timing by a charging ON / OFF signal 116 and a discharging ON / OFF signal 117. Further, the capacitor control unit 112 can distinguish between the OFF / SLEEP mode and other modes based on a signal 126 from a main control unit (not shown) of the image forming apparatus. In the capacitor control unit 112, as a means for realizing the control function, the CPU 109 that executes the arithmetic function and the like according to the program irregularities and data stored in the ROM 110, the ROM 110 that stores the program and data to be executed by the CPU 109, and the CPU 109 A RAM 111 and the like used as a work area are provided.
The power supply unit 127 is always used for image forming operation, OFF, SLEEP, and standby modes, and generates a necessary power supply from the commercial power supply 128. Each power source generated by the power source unit 127 is supplied to the electric component 114 that needs to be supplied also in each mode of the power source 125 of the capacitor control unit, the power source 115 for charging the power storage device 105, and the OFF and SLEEP modes.
JP 2004-266984 A

However, the above-described prior art has the following problems. That is, in Patent Document 1, since power is supplied from the sub power source (capacitor) during the image forming operation or the standby mode, it is described as an OFF mode or a SLEEP mode (hereinafter referred to as “OFF / SLEEP mode”). ), There is no idea of using a sub power source (capacitor). Also, in the example of FIG. 12, the sub power source (capacitor) is exclusively used for the fixing DC heater, so there is no idea that it is used for an electrical component that requires a power source in the OFF / SLEEP mode.
Therefore, in any of the conventional examples, in the OFF / SLEEP mode, all necessary power depends on the power of the commercial power supply. The power supply in the OFF mode is supplied to the main control unit that monitors these electrical components in addition to the electrical components described above. In addition, in the SLEEP mode, in addition to the supply destination in the OFF mode, a network monitoring part such as a USB has started up, so power is also supplied here. There is also a configuration in which the dehumidifying heater is turned on only in the OFF / SLEEP mode for the purpose of preventing condensation.
Accordingly, in the OFF / SLEEP mode, a power source of about several tens of watts is required for the above-described supply destination. Even if this level of power source is supplied from a commercial power source, it will be a negative factor for power saving, and will be a burden on the environment and electricity costs. However, no countermeasure has been proposed so far, as it has not been taken into consideration in the above-described prior art.
SUMMARY OF THE INVENTION An object of the present invention is to solve the above-described negative factors that occur in a conventional image forming apparatus having a power saving function for performing an operation in the OFF / SLEEP mode, and to achieve further power saving.

The invention of claim 1 is an image forming apparatus, and a power supply unit consisting of power storage device receiving the charge from the connected main power supply and the main power to a commercial power supply, stop and power from the previous SL power unit to supply destination When operating in each mode of the first mode in which switching is performed and the image is formed , the second mode in which it is possible to immediately shift to the first mode, and the third mode in which power is supplied only to some devices A power supply control unit that controls power supply of the power supply , and a charge / discharge control unit that controls charge / discharge of the power storage device and performs discharge control of the power storage device when operating in the third mode, control unit, said during the operation of the third mode, supplies power from the discharged said power storage device to at least the charging and discharging control unit said third mode of operation when the supply destination including, and said power storage When all the charges charged in the device are discharged , Characterized in that to stop the power supply to the charging and discharging control unit.
According to a second aspect of the present invention, in the image forming apparatus according to the first aspect, the power supply control unit supplies power to a corresponding supply destination during operation in the third mode between the main power supply and the power storage device. characterized by comprising a means for controlling the switching.
According to a third aspect of the present invention, in the image forming apparatus according to the first or second aspect, an electric double layer capacitor is used for the power storage device.
According to a fourth aspect of the present invention, in the image forming apparatus according to any one of the first to third aspects, the supply destination at the time of the operation in the third mode that receives the power supply from the power storage device is the first It is at least one of means for generating a signal for returning to the mode and network monitoring means.
According to a fifth aspect of the present invention, in the image forming apparatus according to any one of the first to fourth aspects, the charge / discharge control unit performs charge control of the power storage device prior to the transition to the third mode. It is characterized by.
The power supply control method according to claim 6 is a power supply control method in which power supply from a power supply unit comprising a main power source connected to a commercial power source and a main power source and capable of charge / discharge control to a supply destination is stopped. In each mode of the first mode in which image formation is performed by switching, the second mode in which the mode can be immediately shifted to the first mode, and the third mode in which power is supplied only to some devices. A discharge control step of discharging the charge of the power storage device during the operation of the power supply, and a power source to the supply destination during the operation of the third mode is switched between the main power source and the power storage device, and the third mode A power supply control step for switching power to be supplied from the power storage device to at least the charge / discharge control unit of the power storage device during operation, and all charges charged in the power storage device are discharged during operation in the third mode. The charge / discharge A step of stopping the power supply to the control unit, and having a.
According to a seventh aspect of the present invention, in the power supply control method according to the sixth aspect of the present invention, the method includes a charge control step of charging the power storage device, which is performed prior to the transition to the third mode.
The invention according to claim 8 is a program that causes a computer to function as means for executing each step in the power supply control method according to claim 6 or 7.

According to the present invention, a power storage device is charged with excess power generated when using a commercial power source used as a main power source, and components that require power supply in the OFF / SLEEP mode (particularly, a charge / discharge control unit of the power storage device is also included). By supplying power to this power storage device from this power storage device, the power used in the OFF / SLEEP mode can be replaced by a commercial power supply, thus increasing the power saving effect. It becomes possible.
Further, when the OFF / SLEEP mode, when all the power of the power storage and power storage device discharge, since so as to stop power supply to the charging and discharging control unit, Ru can further reduce power consumption.
In addition, by charging the power storage device prior to shifting to the OFF / SLEEP mode, the power from the power storage device can be used for a long time in the OFF / SLEEP mode, contributing to power saving and stable operation. Ru is of.
Further, since the to equip a control function of the intended power supply to the OFF / SLEEP mode component that requires power supply when the program to be capable of constituting a readily function implementing section ing.

Embodiments according to the present invention will be described below.
In the following embodiment, the present invention is applied to an MFP based on an electrophotographic color copying machine. However, the MFP is one embodiment, and may be implemented in an image forming apparatus such as a copying machine, a printer, a facsimile machine, and an MFP, which are other image forming apparatuses. The image to be formed does not have to be a color, and even a monochrome image can be implemented in the same manner as in this example.
"Outline of MFP (Composite Image Forming Device)"
FIG. 1 shows a schematic configuration of an MFP based on an electrophotographic color copier according to an embodiment of the present invention.
In the MFP shown in FIG. 1, an image forming unit 1 is disposed in the approximate center of the apparatus, and a paper feeding unit 2 is disposed below the image forming unit 1. The sheet feeding unit 2 includes a sheet feeding tray 21 at each stage, and another sheet feeding device 22 can be added as necessary. Above the image forming unit 1, a reading unit 3 for reading a document is disposed. A paper discharge storage unit 4 is formed on the left side of the image forming unit 1, and the recording paper on which the image is formed is discharged and stored.
The image forming unit 1 has a mechanism for creating a color image by a so-called tandem method. On the endless belt-shaped intermediate transfer belt 5, each color component (usually yellow: Y, magenta: M, (Cyan: C, Black: BK) image forming units 6 are arranged in parallel, and each includes a photosensitive drum 61, a charging device 62, a scanning exposure device 7 using laser light, a developing device 63 using toner, and a toner. And a cleaning device 64.
In this type of image forming process, the toner images of the respective color components formed on the photosensitive drum 61 are superimposed in the process of being transferred to the intermediate transfer belt 5 that rotates in synchronization with the photosensitive drum 61, and are combined as a color image. .
Further, the color image transferred onto the intermediate transfer belt 5 is transferred by the transfer device 51 onto the recording paper supplied from the paper supply unit 2.
In the paper feeding unit 2, unused recording paper is stored in the paper feeding tray 21, and the bottom plate 24 that is rotatably supported rises to a position where the uppermost recording paper can contact the pickup roller 25. Let The recording paper that has come into contact with the pickup roller 25 by the rise of the bottom plate 24 is sent out from the paper feed tray 21 by the rotation of the paper feed rollers 26 and 27, and is conveyed to the registration roller 23.
The registration roller 23 temporarily stops the conveyance of the recording paper, and rotates again at the timing when the positional relationship between the toner image on the intermediate transfer belt 5 transferred from the photosensitive drum 61 and the leading edge of the recording paper becomes a predetermined position. Controlled to start.
The recording paper on which the toner image has been transferred by the transfer device 51 is fixed on the recording paper through the fixing device 8 disposed in the processing path to the paper discharge storage unit 4. In the fixing process, the toner image is pressed onto the recording paper by passing the recording paper on which the toner image is placed between rollers heated to a high temperature by a heater.

The reading unit 3 enables both book reading and sheet-through reading operations. In book reading, a document (not shown) placed on a document table (contact glass) 33 is scanned by a reading optical system, and a document image is read by a CCD (Charge Coupled Device) as an image sensor placed on an imaging surface. Convert. Sheet-through reading is performed by a CCD via a reading optical system clamped at a reading position while conveying a sheet document by an automatic document feeder (ADF) 36 mounted on the upper portion of the reading unit 3 (shared with book reading). Convert the original image. The ADF automatically conveys originals set in a bundle on the original tray one by one.
The image signal read by the CCD is digitized and subjected to image processing such as correction and conversion in order to obtain image formation output data.
Based on the image formation output data obtained by the image processing, the light emission of the LD: laser diode (not shown) in the scanning exposure device 7 is controlled to perform optical writing on the photosensitive drum 61, and the photosensitive member surface An electrostatic latent image is formed. The optical writing is performed by the main / sub two-dimensional scanning method, and the scanning light beam from the LD is supplied in the sub-scanning direction via a rotating polygon mirror related to the main scanning, a correction lens such as fθ and a transmission optical system. The light is projected onto the surface of the photosensitive drum 61 that rotates.
In this example, the MFP has a FAX function, a printer function, and a scanner function in addition to the copying function described above. In the FAX function, after the original is read by the reading unit 3 in FAX transmission, it is converted into a FAX signal and transmitted to the communication line. In FAX reception, after receiving the FAX signal sent from the communication line. The image forming unit 1 forms an image after processing the print output data. Further, the printer function receives print data sent from a host machine such as a PC in response to print output, and then processes the print output data to form an image in the image forming unit 1. In response to a scanner distribution request from a host device such as a PC, the printer function processes document image data read by the reading unit 3 into data in a format that can be used by the host device, and then via communication means. Send. Since these functions themselves are existing techniques, detailed description thereof is omitted here.

Since the MFP is driven by electric power, it has a power supply circuit for supplying electric power to various devices to be operated when using the functions of copying, FAX, printer, and scanner.
This power supply circuit is usually configured to supply a used power supply having a voltage suitable for each device from a main power supply connected to a commercial power supply. In addition, since power supply from the main power supply device to various devices varies depending on the mode and function to be used, the main control unit supplies various devices that operate the power supply from the main power supply device according to user setting conditions during use. Supply power is controlled.
The main control unit has a CPU and provides a function for controlling the entire apparatus by driving various programs by the CPU. The power supply control described above is included in a part of the function.
The present embodiment relates to a power saving operation by power supply control. Note that power supply control is necessary for devices related to operations such as copying, faxing, printers, scanners, etc., according to functions and operating conditions set by the user during use, in addition to power saving operations, which are the issues to be solved in this proposal. Although power is supplied, here, since power supply control in the case of performing a power saving operation is a main problem, detailed description is omitted here.

Conventional power saving operations by power supply control include a standby mode, an OFF mode, and a SLEEP mode.
In the standby mode, the apparatus is made to stand by in a standby state in which it can immediately shift to an image forming operation (that is, a state where the startup takes the longest time, for example, a power supply destination such as a fixing heater can be started up in a short time). To. In the OFF mode, only a device (for example, a document set sensor, an ADF open / close sensor, a power key SW, etc.) for returning to an operation state capable of image formation and a main control unit that monitors this device are started up. The other devices are not powered. In SLEEP mode, the only difference is that in addition to the devices in OFF mode, the network monitoring part such as USB has started up. However, there is also a configuration in which power is supplied to turn on the dehumidifying heater only during the power saving operation in the OFF / SLEEP mode for the purpose of preventing condensation regardless of the power saving operation.
In the present embodiment, the power source of the power storage device provided as the sub power source is used in the above-described OFF / SLEEP mode. The power storage device used here has been used in the OFF / SLEEP mode by storing excess power generated when using the main power supply connected to the commercial power supply and using this as the power supply for the OFF / SLEEP mode. This makes it possible to increase the power saving effect while consuming as little commercial power as possible.
The following is an electrical component that needs to be powered in the OFF / SLEEP mode from a power storage device provided as a sub power supply (for example, a device that generates a return signal by sensing an operation that causes a return from the OFF / SLEEP mode) Examples of different forms of the power supply circuit section that can supply power to the circuit or the like constituting the main control section will be described as “Embodiment 1” to “Embodiment 5”.

“Embodiment 1”
In the present embodiment, a basic configuration of a power supply circuit unit that supplies power from a power storage device provided as a sub power supply to an electrical component or the like that needs to be supplied in the OFF / SLEEP mode is shown.
FIG. 2 shows a configuration of a power supply circuit unit according to the present embodiment provided with a power storage device as a sub power supply.
The power supply device in the power supply circuit unit shown in FIG. 2 includes a power supply unit 127 connected to a commercial power supply 128 as a main power supply, and a power storage device 105 including a capacitor bank that receives charge from the power supply unit 127 as a sub power supply.
In the capacitor bank 105, there is a circuit in which the capacitor cells 101, 102,. Further, the capacitor cells 101, 102,... Have balance circuits 103, 104,. The capacitor cells 101, 102,... Have individual differences such as capacitance differences and internal impedance differences, and the charging time of each capacitor cell is different. If the capacitor bank voltage is charged for the target, depending on the capacitor cell, the battery is charged exceeding the rated voltage, and the reliability is impaired. When it is detected that one capacitor cell has reached the rated voltage and charging is stopped, the capacitor bank voltage may not reach the target voltage and the capacitor bank energy may not be sufficiently obtained. . Therefore, in order to bypass the charging current in order from the capacitor cell that has been charged and finally make the charging voltages of all the capacitor cells 101, 102,... The same, the balance circuits 103, 104,.・ Established.
In addition, as the capacitor cells 101, 102,... Used for the power storage device 105, electric double layer capacitors can be adopted. The electric double layer capacitor is characterized by the fact that the terminal voltage decreases with discharge, so a DC / DC converter (DDC) must be used.

Charging / discharging of the capacitor bank 105 is performed via a charger 107 and a DC / DC converter (DDC) 108.
The charger 107 charges the capacitor bank 105. The charger 107 receives a power source 115 for charging the capacitor bank from the power source unit 127. The power source 115 for charging the capacitor bank is a power source that is always used in all operation modes of the image forming apparatus such as standby, operation, and OFF / SLEEP mode. The power source 115 for charging the capacitor bank is voltage-converted by the DDC 106 in accordance with the rated voltage of the capacitor bank 105.
The DDC 108 provided on the discharge side of the capacitor bank 105 is a converter that converts the power sources 121 and 122 from the capacitor bank 108 to a voltage required at the supply destination when the power source 121 or 122 is supplied to the electric component 114 via the charger 107.
The electrical component 114 is a component that requires power supply in the OFF / SLEEP mode. Here, as the electrical component 114, a dehumidifying heater 131, an ADF document sensor 129 that detects a return factor from the OFF / SLEEP mode and generates a return signal, and a document set sensor 130 are illustrated.

The capacitor control unit 112 controls charging / discharging of the capacitor bank 105 at a predetermined timing by a charge ON / OFF signal 116 and a discharge ON / OFF signal 117. Further, the capacitor control unit 112 can distinguish between the OFF / SLEEP mode and other modes based on a signal 126 from a main control unit (not shown) of the image forming apparatus. In the capacitor control unit 112, as means for realizing the control function, the CPU 109 that executes a calculation function or the like according to program irregularities or data stored in the ROM 110, the ROM 110 that stores a program or data for the CPU 109 to execute processing, A RAM 111 and the like used as a work area for the CPU 109 are provided.
The power supply unit 127 generates a power supply necessary for each mode of image forming operation, OFF, SLEEP, and standby from the commercial power supply 128. Each power source generated by the power source unit 127 is supplied as a power source 125 for the capacitor control unit 112 and a power source 115 for charging the power storage device 105.
When the image forming apparatus is in the OFF / SLEEP mode, the capacitor control unit 112 detects the OFF / SLEEP mode, generates a charge OFF signal 116, operates the charger 107 by this signal, and transfers to the capacitor bank 105. Stop charging. At the same time, a discharge ON signal 117 is generated, the DDC 108 is operated by this signal, and discharge from the capacitor bank 105 to the supply destination is started. With this operation, power can be supplied from the capacitor bank 105 to the electrical component 114 that requires power in the OFF / SLEEP mode.

By the above-described basic operation of the power supply circuit that supplies power from the capacitor bank 105 in the OFF / SLEEP mode, it is possible to use the power stored in the capacitor bank 105 by the electrical component 114 that requires power in the OFF / SLEEP mode. become.
However, if the electrical component 114 is the dehumidifying heater 131, the ADF document sensor 129, and the document set sensor 130 as in this example, the power can be supplied even during the image forming operation other than the OFF / SLEEP mode and in the standby mode. Necessary, that is, power supply is always required. Therefore, for the electrical component 114 under such conditions, power is supplied from the power supply unit 127 (connected to the commercial power supply 128), which is the main power supply, except in the OFF / SLEEP mode. It is desirable to add a switching circuit for continuously supplying power.
Therefore, a circuit configuration as a power supply circuit for the electrical component 114 that always requires power supply is added by adding a power supply switching circuit that switches the power supply to the electrical component 114 from one of the capacitor bank 105 and the power supply unit 127 to the other. Meet the above requirements. 2 shows an example in which the power supply switching circuit 113 is added to the power supply circuit section shown in FIG.
The power supply switching circuit 113 shown in FIG. 2 switches the power supply 123 of the capacitor bank 105 system and the power supply 119 of the power supply section 127 system by a control signal 118 from the capacitor control unit 112.

FIG. 3 shows an example of the internal configuration of the power supply switching circuit 113.
In the power supply switching circuit 113, the power supply 124 to the electrical component 114 that needs to be supplied with power in the OFF / SLEEP mode is converted into a predetermined voltage DC by the power supply 123 from the capacitor bank 105 and the commercial power supply 128 by the power supply unit 127. This is a circuit for switching the power source 119. The power supply 119 from the commercial power supply unit 127 is a power supply that can be used at all times in all operation modes such as a standby mode, an image forming operation, and an OFF / SLEEP mode.
The power supply switching circuit 113 is a simple circuit using elements such as FETs (Field Effect Transistors) 132 and 133, and switches between the power supply 119 and the power supply 123 by a switching control signal 118 from the capacitor control unit 112.
When the image forming apparatus shifts to the OFF / SLEEP mode, the capacitor control unit 112 that receives the control signal 126 from the main control unit (not shown) detects the OFF / SLEEP mode from the control signal 126, and the charge OFF signal The charging of the capacitor bank 105 is stopped by 116, and the DDC 108 is operated by the discharge ON signal 117 to start discharging from the capacitor bank 105.
Thereafter, the switching control signal 118 from the capacitor control unit 112 that controls switching of the power source 119 from the commercial power source unit 127 and the power source 123 from the capacitor bank 105 is changed to a high level. As a result, the output side of the inverter 142 becomes low level, the transistor Q139 is turned off, the FET 133 is turned off, and the power supply of the power supply 119 from the commercial power supply unit 127 is stopped. Further, the output side of the inverter 143 is at a low level, and the output side of the inverter 144 is at a high level. As a result, the transistor Q138 is turned on and the FET 132 is turned on, and the power supply 123 from the capacitor bank 105 is supplied as the power supply 124 to the electrical component 114 that needs to be supplied with power in the OFF / SLEEP mode.

On the other hand, when the image forming apparatus returns from the OFF / SLEEP mode, the capacitor control unit 112 that receives the control signal 126 from the main control unit (not shown) detects the return from the OFF / SLEEP mode from the control signal 126. Thus, the switching control signal 118 from the capacitor control unit 112 that controls switching between the power source 119 from the commercial power source unit 127 and the power source 123 from the capacitor bank 105 is changed to a low level. As a result, the output side of the inverter 143 becomes high level, and the output side of the inverter 144 becomes low level. For this reason, the transistor Q138 is turned off, the FET 132 is turned off, and the power supply of the power supply 123 from the capacitor bank 105 is stopped. Further, the output side of the inverter 142 is at a high level, the transistor Q139 is turned on, the FET 133 is turned on, and the power supply 119 from the commercial power supply unit 127 supplies the power supply 124 to the electrical component 114 that needs to supply power in the OFF / SLEEP mode. Supplied as
By configuring the power supply circuit as described above, when power is supplied to the electrical component 114 that requires power in the OFF / SLEEP mode, when returning from the OFF / SLEEP mode to the image forming operation mode, the image forming operation is also performed. When switching from mode to OFF / SLEEP mode, the power stored in the capacitor is used in OFF / SLEEP mode, and the commercial power is used in image forming operation mode. The component 114 can be continuously supplied with power.

“Embodiment 2”
In this embodiment, the capacitor is charged in the OFF / SLEEP mode based on the circuit of the above-described “Embodiment 1” (FIG. 2) shown as the basic configuration of the power supply circuit unit including the power storage device provided as the sub power supply. A power supply circuit unit to which a capacitor control unit 112 is added as a power supply destination is shown. That is, in the power supply circuit unit shown in FIG. 2, the electrical component 114 that needs to be supplied with power in the OFF / SLEEP mode is set as the supply source of the sub power supply. By adding the capacitor control unit 112 to this supply destination, the sub power supply It aims at further enlarging the merit by using the power storage device provided.
FIG. 4 shows a configuration of a power supply circuit unit according to the present embodiment provided with a power storage device as a sub power supply.
The power supply circuit unit shown in FIG. 4 switches the power supply to the electrical component 114 between the power supply 119 and the power supply 123 by the power supply switching circuit 113 in the circuit of the above-mentioned “embodiment 1” (FIG. 2). Similarly to the capacitor control unit 112, a power supply switching circuit (II) 148 is provided to switch the supply of the power supply 147 of the capacitor bank 105 system and the power supply 125 of the power supply unit 127 system.
The power supply circuit of this embodiment shown in FIG. 4 is the same as the power supply circuit (FIG. 2) shown in the previous embodiment except that a power supply switching circuit (II) 148 is newly provided. In the present embodiment, since the power supply switching circuit (II) 148 is provided, naturally, there is no power supply 125 that can be supplied directly from the power supply unit 127 shown in FIG. The power switching circuit (I) 113 is the same circuit as the power switching circuit 113 shown in FIG.

The power supply switching circuit (II) 148 receives the switching control signal 118 from the capacitor control unit 112 and is always used in all operation modes generated by a commercial power supply such as a standby mode, an image forming operation, and an OFF / SLEEP mode. Switching is possible between a possible power source 125 and a power source 147 supplied from the capacitor bank 105 via the DDC 108, and either power source can be supplied as the power source 146 of the capacitor control unit 112.
The power supply switching circuit (II) 148 can be configured by using a simple element such as the Relay 140 operated by the switching control signal 118. Further, when the voltage level of the power source 147 supplied from the capacitor bank 105 is different from that of the power source that can be used by the capacitor control unit 112, the voltage may be converted using a voltage conversion IC such as the DDC 45.
When the image forming apparatus shifts to the OFF / SLEEP mode, the capacitor control unit 112 that receives the control signal 126 from the main control unit (not shown) detects the OFF / SLEEP mode and generates the charge OFF signal 116. In response to this signal, the charger 107 is operated to stop charging the capacitor bank 105. At the same time, a discharge ON signal 117 is generated, the DDC 108 is operated by this signal, and discharge from the capacitor bank 105 to the supply destination is started. With this operation, power can be supplied from the capacitor bank 105 to the capacitor control unit 112 that requires power in the OFF / SLEEP mode. As shown in “Embodiment 1,” the power sources 123 and 124 are also supplied from the capacitor to the electrical component 114 that requires the power source in the OFF / SLEEP mode at the same timing.

However, since the power from this capacitor supplies power to the capacitor control unit 112 only in the OFF / SLEEP mode, it is input to this switching circuit as one power source 147 switched in the power switching circuit (II) 148.
In addition, a switching control signal 118 for switching the voltage from the commercial power source, which is the other power source switched in the power source switching circuit (II) 148, and the power source 147 from the capacitor is input from the capacitor control unit 112. Is done. When the switching control signal 118 from the capacitor control unit 112 becomes a high level, the transistor 149 is turned on, and the contact of the Relay 140 is switched to the power source 147 from the capacitor. Thereby, the power source 147 from the capacitor can be supplied for the power source of the capacitor control unit 112.
On the other hand, when the image forming apparatus returns from the OFF / SLEEP mode, the capacitor control unit 112 that receives the control signal 126 from the main control unit (not shown) detects the return from the OFF / SLEEP mode and switches to it. The control signal 118 is switched to the low level. When the switching control signal 118 is switched to the low level, the transistor 149 is turned OFF, and the contact of the Relay 140 is switched to the power source 125 on the commercial power source side that can be used in the standby mode and the image forming operation mode. Thereby, the power source 125 can be supplied for the power source of the capacitor control unit 112.

“Embodiment 3”
This embodiment is based on the circuit of the above “Embodiment 2” (FIG. 4) shown as a power supply circuit unit provided with a power storage device provided as a sub power supply, and supplies the power stored in the capacitor in the OFF / SLEEP mode. The power supply circuit part provided with the structure which enables it to perform operation | movement reliably is shown.
This mechanism is a control signal output from the capacitor control unit 112 by feeding back the detection result of the charge state of the capacitor and the discharge operation state of the capacitor to the capacitor control unit 112 in the power supply circuit (FIG. 4) of “Embodiment 2”. The charging ON / OFF signal 116, the discharging ON / OFF signal 117, and the switching control signal 118 can be output at appropriate timing. In the following embodiment (FIG. 5), an example based on the power supply circuit of FIG. 4 is shown, but it is needless to say that the power supply circuit of FIG.
FIG. 5 shows a configuration of a power supply circuit unit according to this embodiment including a power storage device as a sub power source.
In the power supply circuit unit shown in FIG. 5, in order to perform the above-described feedback, the charger 107 detects the capacitor charging operation and the capacitor charging voltage, and these detection results are used as the capacitor charge state feedback signal 150 to Output to the control unit 112. Further, the DDC 108 detects the discharge operation of the capacitor, and outputs the detection result to the capacitor control unit 112 as a feedback signal 151 of the discharge state of the capacitor. Although this point is different from the power supply circuit of FIG. 4 (FIG. 4), there is no difference in hardware configuration other than that.

Here, in the power supply circuit having the above-described configuration, the control operation of the power supply to the electrical components or the like (electrical components 114, the capacitor control unit 112, etc.) that require power supply in the OFF / SLEEP mode, which is performed by the capacitor control unit 112. Will be explained.
FIG. 6 shows a control flow diagram of the power supply operation according to the present embodiment when shifting to the OFF / SLEEP mode.
This control flow is executed in accordance with the control operation of the capacitor control unit 112 that receives an OFF / SLEEP mode instruction issued by a main control unit (not shown). The capacitor control unit 112 executes the operation of this control flow by driving a control program for executing the power supply operation in the OFF / SLEEP mode by the CPU 109 in the control unit in accordance with the instruction.
When the image forming apparatus shifts from a state other than the OFF / SLEEP mode to the OFF / SLEEP mode at the beginning of the power supply control flow, control conditions necessary for the operation in the mode after the shift are adjusted (step S101).
As an operation in the OFF / SLEEP mode after the transition, first, an operation for forcibly stopping the charging of the capacitor is started (step S102). Charging is stopped by transmitting a charging OFF signal 116 from the capacitor control unit 112 to the charger 107 and performing a charging stopping operation in the charger 107 in accordance with the charging OFF signal 116.

The charger 107 detects a charge stop state, and informs the capacitor control unit 112 of the stop state as a feedback signal 150 at the time of detection. Therefore, the capacitor control unit 112 checks the feedback signal 150 informing the charge stop state at a predetermined timing, and confirms that the charge is actually stopped according to the check result (step S103-YES). This feedback signal 150 check is repeated.
After confirming that the capacitor is in the charge stop state, the discharging operation from the capacitor is started (step S104). For discharging from the capacitor, a discharge ON signal 117 is transmitted from the capacitor control unit 112 to the DDC 108, a voltage discharged from the capacitor bank 105 is converted by the DDC 108 in accordance with the discharge ON signal 117, and supplied as the power source 123.
At this time, the DDC 108 detects the discharge state, and informs the capacitor control unit 112 of the discharge state as a feedback signal 151 at the time of detection. Therefore, the capacitor control unit 112 checks the feedback signal 151 that informs the discharge state at a predetermined timing, and confirms that the discharge is actually performed based on the check result (step S105-YES). The check of the feedback signal 151 is repeated.
After confirming that the capacitor is in a discharged state, the capacitor control unit 112 next transmits a high-level switching control signal 118 to the power switching circuit (I) 113 and the power switching circuit (II) 148. From the commercial power supply side power supply 119 and the power supply 125 supplied to the electrical component 114 and the capacitor control unit 112 to the power supply 123 and the power supply 147 supplied from the capacitor bank 105 via the DDC 108, respectively, until the transition to the OFF / SLEEP mode). Switching and supplying (step S106), the control flow is exited. The operations of the power switching circuit (I) 113 and the power switching circuit (II) 148 at this time are the same as the description of the power switching circuit 113 (FIG. 3) in the “embodiment 1” and the “embodiment 2”. This is as shown in the description of the power supply switching circuit (II) 148 (FIG. 4).

Further, another embodiment of the power supply control for the electric parts and the like that require power supply in the OFF / SLEEP mode in the power supply circuit (FIG. 5) will be described.
In the power supply control flow (FIG. 6) in the power supply circuit (FIG. 5), the capacity that can be stored in the capacitor bank 105 is sufficiently large, and the power is not cut off due to the consumption during the OFF / SLEEP mode. In this case, there is no problem in operation.
However, depending on the specifications, when there is a possibility that the power supply is cut off, it is necessary to secure the power supply and to guarantee the operation. Therefore, in the embodiment shown below, the voltage drop in the charging voltage of the capacitor is checked, and before the power of the capacitor is turned off, the power source is switched to the commercial power source side, and the necessary power source can be secured.
The capacitor control unit 112 switches the power source between the capacitor side and the commercial power source side by transmitting a high / low level switching control signal 118 to the power source switching circuit (I) 113 and the power source switching circuit (II) 148. What can be done is as described in the description of the power supply switching circuit 113 (FIG. 3) of the “Embodiment 1” and the description of the power supply switching circuit (II) 148 (FIG. 4) of the “Embodiment 2”. Therefore, the capacitor control unit 112 to which the charging voltage of the capacitor detected by the charger 107 is fed back is used to determine the state immediately before the capacitor is turned off due to the decrease in the charging voltage of the capacitor, and the power supply is connected to the commercial power supply side. It becomes possible to switch to.

FIG. 7 shows a control flow diagram of the power supply operation for switching the power source to the commercial power source side before the power source of the capacitor used in the OFF / SLEEP mode is turned off and securing the power source.
Steps S201 to S206 in the first half of the control flow shown in FIG. 7 are the same as steps S101 to S106 in the control flow shown in FIG. 6, so they are described here instead of the above description made with reference to FIG. Is omitted.
Since the power supply to the electric component 114 and the capacitor control unit 112 that require power supply in the OFF / SLEEP mode uses the power supply of the capacitor as much as possible, it is a proposition here. By executing S206, the supply power source is switched at the time of transition to the OFF / SLEEP mode, and then the power source 123 and the power source 147 supplied from the switched capacitor bank 105 via the DDC 108 are replaced with the electric component 114 and the capacitor control unit 112, respectively. (Step S207).
During the OFF / SLEEP mode, the power supply of the capacitor is continuously supplied. However, if this period becomes longer, the charged amount may be consumed and the use limit may be reached. Therefore, the capacitor control unit 112 is detected by the charger 107 and fed back. The capacitor charging voltage transmitted as the signal 150 is monitored (step S208).

Here, when the capacitor charging voltage that is repeatedly checked at a predetermined timing decreases to a voltage at which power cannot be supplied to the electric component 114 and the capacitor control unit 112 that require power in the OFF / SLEEP mode, the electric component 114 and the capacitor The power source for the control unit 112 is switched from the capacitor side to the commercial power source side (step S209). That is, the capacitor control unit 112 transmits a low level switching control signal 118 to the power supply switching circuit (I) 113 and the power supply switching circuit (II) 148, and has been supplied to the electrical component 114 and the capacitor control unit 112, respectively. The capacitor-side power supply 123 and power supply 147 are switched from the commercial power supply side to the power supply 119 and power supply 125 supplied via the power supply unit 127.
Since it is necessary to stop the discharge from the capacitor when the power supply is switched, the discharge stop operation is started (step S210). To stop the discharge from the capacitor, the capacitor controller 112 sends a discharge OFF signal 117 to the DDC 108, stops the conversion of the voltage discharged from the capacitor bank 105 by the DDC 108 in accordance with the discharge OFF signal 117, and outputs the power sources 123 and 147. 0.
At this time, the DDC 108 detects the discharge state, and informs the capacitor control unit 112 of the discharge state as a feedback signal 151 at the time of detection. Accordingly, the capacitor control unit 112 checks the feedback signal 151 that informs the discharge state at a predetermined timing, and confirms that the discharge is not actually performed based on the check result (step S211—YES). The check of the feedback signal 151 is repeated.
After confirming that there is no discharge from the capacitor (step S211-YES), the control flow is exited.

FIG. 8 is a diagram conceptually showing a change in power supplied by the power control operation in the OFF / SLEEP mode in the power supply circuit (FIGS. 2, 4, and 5) of each embodiment of the present invention described above. It is.
In the diagram of FIG. 8, the horizontal axis represents time t, and the vertical axis represents the power W required by the power supply unit 127 on the commercial power supply side. The period (1) shown on the time axis is a period other than the OFF / SLEEP mode (image forming operation mode, standby mode), and the period (2) indicates the period of the OFF / SLEEP mode.
In period (1), power is supplied to the fixing heater and the like necessary for image formation. Therefore, the power W required for the power supply unit 127 on the commercial power supply side is large, and the OFF / SLEEP mode period (2 ), The power will be low.
The power for period (2) is as shown in FIG. 8, assuming that all of the electrical components (electrical component 114, capacitor control unit 112, etc.) that need to be supplied in the OFF / SLEEP mode are supplied by the power supply unit 127 on the commercial power supply side. As in (5), a power source indicated by the amount of power W1 is required. In the present embodiment, in the power supply circuits of FIGS. 4 and 5, when the power supply on the capacitor side is cut off, power is supplied from the power supply unit 127 on the commercial power supply side to the electrical component 114, the capacitor control unit 112, and the like (FIG. 7). W1 is required for the control flow (see Fig. 2). In the conventional apparatus (FIG. 12), power is supplied from the power supply unit 127 on the commercial power supply side to the electrical component 114 that needs to be supplied in the OFF / SLEEP mode, which corresponds to this case.
Further, in the power supply circuit of the power supply circuit (FIGS. 2, 4, and 5) of the above embodiment, when supplying power on the capacitor side to an electrical component or the like that requires power supply in the OFF / SLEEP mode, a commercial power supply The power supply unit 127 on the side requires a power supply indicated by the amount of power W2, as indicated by (4) in FIG. The amount of power W2 indicates that the power source on the commercial power source side is used in addition to the power source on the capacitor side in the OFF / SLEEP mode. In this embodiment, the power amount to the main control unit (not shown) This is because, as in the power supply circuit shown in the second embodiment, the power supply to the capacitor control unit 112 supplies the power supply on the commercial power supply side.
Therefore, the OFF / SLEEP mode is the difference between the amount of power W1 when using the power source on the commercial power source and the amount of power W2 when using the power source on the capacitor side, as shown in (3) in FIG. Sometimes the power required by the power supply unit 127 on the commercial power supply side can be reduced.

“Embodiment 4”
The present embodiment is based on the circuit of the above-described “Embodiment 3” (FIG. 5) shown as a power supply circuit unit provided with a power storage device provided as a sub power supply, and the power supply on the capacitor side used in the OFF / SLEEP mode FIG. 6 shows a power supply circuit unit having a mechanism for shutting off the commercial power supply side power supplied to the capacitor control unit 112 and further reducing the power in the OFF / SLEEP mode when the power supply disappears completely.
This mechanism includes a control means for shutting off the commercial power supply-side power supply 125 supplied to the capacitor control unit 112 via the power supply switching circuit (II) 148 in the power supply circuit (FIG. 5) of “Embodiment 3”. It constitutes.
FIG. 9 shows a configuration of a power supply circuit unit according to this embodiment including a power storage device as a sub power supply.
In the power supply circuit section shown in FIG. 9, a power supply section 127 as a main power supply for supplying power on the commercial power supply side has a DDC 155 that generates power for the capacitor control section 112, and an output ON / OFF of the DDC 155 latch control signal. A latch circuit 154 that can be controlled by 152 and 153 is provided. The power supply circuit section shown in FIG. 9 is provided with a DDC 155 and a latch circuit 154, and the power supply section 127 is added with a configuration in which the power supply for the capacitor control section 112 is cut off (see FIG. 5). ), But other than that, there is no difference in hardware configuration.
The interruption of the power supply 125 supplied from the power supply unit 127 to the capacitor control unit 112 is controlled by a control signal 152 that turns on the latch from the capacitor control unit 112.
Capacitor control unit 112 confirms that the power supply on the capacitor side used in the OFF / SLEEP mode has completely disappeared by, for example, the charging voltage of the capacitor indicated by feedback signal 150 from charger 107, and confirms that Then, a control signal 152 for turning on the latch is transmitted to the power supply unit 127.
The power supply unit 127 operates the latch circuit 154 according to the received control signal 152, latches the DDC 155, cuts off the power supply 125 output to the switching circuit (II) 148, and supplies it to the capacitor control unit 112. power off.
As described above, when the capacitor control unit 112 is started up again after the power supply 125 supplied to the capacitor control unit 112 is shut off, the latch of the latch circuit 154 is released, but the control signal 153 for turning off this latch is used. Is issued from a main control unit (not shown), and the latch circuit 154 is released upon receiving this control signal 153, and the power supply 125 from the power supply unit 127 is supplied to the capacitor control unit 112.

Here, in the power supply circuit having the above-described configuration, a control operation for cutting off the commercial power supply side power supplied to the capacitor control unit 112 in the OFF / SLEEP mode will be described according to a flow.
FIG. 10 shows a control flowchart of the power supply operation according to the present embodiment.
This control flow is executed by the capacitor control unit 112 as part of the control operation in the OFF / SLEEP mode. The capacitor control unit 112 switches to the power supply on the commercial power supply side after the power supply on the capacitor side is cut off by the control flow (FIG. 7) of power supply to the capacitor control unit 112 in the OFF / SLEEP mode as described above. This control flow is started at the time of switching.
At the beginning of this control flow, the power supply to the electrical components that require power supply in the OFF / SLEEP mode (electrical component 114, capacitor control unit 112, etc.) is switched to the power source on the commercial power source side and power supply is started ( Step S301). That is, the capacitor control unit 112 uses the power supply switching circuit (I) 113 and the power supply switching circuit (II) 148 to supply the capacitor-side power supply 123 and the power supply 147 that have been supplied to the electrical component 114 and the capacitor control unit 112, respectively. After switching, the supply of the power supply 119 and the power supply 125 is started from the commercial power supply side via the power supply unit 127.
Since it is necessary to stop the discharge from the capacitor when the power supply is switched, the discharge stop operation is started (step S302). To stop the discharge from the capacitor, the capacitor controller 112 sends a discharge OFF signal 117 to the DDC 108, stops the conversion of the voltage discharged from the capacitor bank 105 by the DDC 108 in accordance with the discharge OFF signal 117, and outputs the power sources 123 and 147. 0.
At this time, the DDC 108 detects the discharge state, and informs the capacitor control unit 112 of the discharge state as a feedback signal 151 at the time of detection. Therefore, the capacitor control unit 112 checks the feedback signal 151 that informs the discharge state at a predetermined timing, and confirms that the discharge is not actually performed based on the check result (step S303-YES). The check of the feedback signal 151 is repeated.

After confirming that there is no discharge from the capacitor (YES in step S303), the capacitor control unit 112 monitors the charging voltage of the capacitor detected by the charger 107 and transmitted as the feedback signal 150. (Step S304).
Next, it is checked whether or not the capacitor charging voltage that is repeatedly monitored at a predetermined timing has reached the voltage value in a state where all the power sources are discharged from the capacitor (step S305).
When the discharge state check confirms that all the power has been discharged from the capacitor (step S305-YES), the supply of the commercial power source 125 that supplies power to the capacitor control unit 112 is stopped. (Step S306).
This power supply stop operation is controlled by the capacitor control unit 112. That is, the capacitor control unit 112 transmits a control signal 152 for turning on the latch to the latch circuit 154 in the power supply unit 127 that supplies power on the commercial power supply side, and the power supply unit 127 that receives this control signal 152 turns on the latch. The latch circuit 154 is operated by the signal to latch, the DDC 155 is latched, the power supply 125 output to the switching circuit (II) 148 is shut off, and the supply of power supplied to the capacitor control unit 112 is stopped.
By stopping the supply of power to the capacitor control unit 112 that does not need to supply power by the power control described above, it is possible to further reduce the power in the OFF / SLEEP mode.

“Embodiment 5”
This embodiment makes it possible to charge a power storage device provided as a sub power source in the power supply circuit unit shown in the above embodiment prior to shifting to the OFF / SLEEP mode, and to store power in the OFF / SLEEP mode. By allowing the power from the device to be used for a long period of time, it is intended to contribute to power saving and to stabilize the operation.
In this charging operation, as in the power supply circuit units shown in the embodiments of FIGS. 5 and 9, the charger 107 detects the charged state of the capacitor and feeds back the detected charged state to the capacitor control unit 112. Can be realized by executing the following control flow.
FIG. 11 shows a control flow chart of the charging operation according to the present embodiment performed at the time of shifting to the OFF / SLEEP mode.
The control flow shown in FIG. 11 is executed by the main control unit (not shown) and the capacitor control unit 112 as part of the control operation in the OFF / SLEEP mode. The main control unit activates this control flow prior to shifting to the operation of the OFF / SLEEP mode in which power is supplied from the capacitor to the electrical components or the like that require power supply as described above.
At the beginning of this control flow, the operating conditions necessary for the transition control to the OFF / SLEEP mode are prepared (including condition setting for executing this control flow), and preparation for transition is made (step S401).

Next, when the capacitor bank 105 is not charged, a charging operation is performed at a later stage. At this time, it is checked whether or not the capacitor control unit 112 that performs charging control is started (step S402). Here, if the capacitor control unit 112 is not started up, it is necessary to supply power to the capacitor control unit 112 and start up (step S403). If the capacitor bank 105 is not charged at this time, a latch release signal 153 is sent to the power supply unit 127 and the power supply unit 127 releases the latch of the latch circuit 154. An operation of supplying power and starting up the capacitor control unit 112 is performed.
After starting up the capacitor control unit 112, the capacitor control unit 112 is instructed to start charging. In accordance with this instruction, the capacitor control unit 112 starts charging the capacitor bank 105 by sending a charge ON signal 116 to the charger 107 (step S404).
Thereafter, the capacitor control unit 112 monitors the charging voltage of the capacitor detected by the charger 107 and transmitted as the feedback signal 150, and determines the completion of charging from the monitored voltage (step S405).
When the charging voltage of the capacitor is repeatedly monitored at a predetermined timing, and it is determined that the charging voltage of the capacitor has reached the voltage value in a state where the charging has been completed (step S405-YES), the capacitor control unit 112 receives the charging OFF signal. By sending 116, charging of the capacitor bank 105 is stopped (step S406).
After stopping the charging of the capacitor, the operating conditions necessary for the control necessary for the operation in the OFF / SLEEP mode are adjusted, and the operation mode is shifted to (step S407), and the control flow is exited.

1 shows a schematic configuration of an MFP based on an electrophotographic color copier according to an embodiment of the present invention. The structure of the power supply circuit part which concerns on Embodiment 1 provided with the electrical storage apparatus as a sub power supply is shown. 3 shows an example of the internal configuration of a power supply switching circuit in the power supply circuit section shown in FIG. The structure of the power supply circuit part which concerns on Embodiment 2 provided with the electrical storage apparatus as a sub power supply is shown. The structure of the power supply circuit part which concerns on Embodiment 3 provided with the electrical storage apparatus as a sub power supply is shown. FIG. 9 is a control flowchart of a power supply operation according to the third embodiment when shifting to an OFF / SLEEP mode. The control flow diagram of the power supply operation for switching to the power supply on the commercial power supply side before the capacitor power supply used in the OFF / SLEEP mode is turned off is shown. It is a diagram which shows notionally the change of the electric power supplied by the power supply control operation at the time of OFF / SLEEP mode. The structure of the power supply circuit part which concerns on Embodiment 4 provided with the electrical storage apparatus as a sub power supply is shown. FIG. 10 shows a control flow diagram of a power supply operation for shutting off the power on the commercial power supply side supplied to the capacitor control unit in the OFF / SLEEP mode in the power supply circuit unit of FIG. 9. FIG. 10 is a control flow diagram of a charging operation performed at the time of shifting to the OFF / SLEEP mode in the power supply circuit unit of FIG. 9. A conventional example of a power supply circuit of an image forming apparatus using a power storage device that receives charge from a main power supply as a sub power supply is shown.

Explanation of symbols

    1 .... Image forming unit 2 .... Feeding unit 3 .... Reading unit 8 .... Fixing device 36 ... ADF (automatic document feeder) 61 ... Photoconductor drum 63 ... Developing device 105 ·· Power storage device (capacitor bank), 107 ·· Charger, 108 ·· DC / DC converter (DDC), 112 · · Capacitor control unit, 113 · · Power supply switching circuit (I), 114 · · OFF / SLEEP Electrical parts that require power supply in mode 127, Power supply section (main power supply), 128 Commercial power supply 148 Power switching circuit (II) 140 Fixing DC heater

Claims (8)

A power supply unit composed of a main power source connected to a commercial power source and a power storage device receiving charge from the main power source ;
Perform power of stopping and switching from the previous SL power unit to supply destination, a first mode for forming an image, the first mode immediately migratable second mode, the power only a part of the device supply A power supply control unit for controlling power supply during operation in each mode of the third mode ,
A charge / discharge control unit that controls charge / discharge of the power storage device and performs discharge control of the power storage device during operation of the third mode;
With
The power supply control unit, during operation of the third mode, supplies power from the discharged said power storage device to at least the charging and discharging control unit said third mode of operation when the supply destination including, The power supply to the charge / discharge control unit is stopped when all the electric charges charged in the power storage device are discharged . The image forming apparatus according to claim 1,
The image forming apparatus according to claim 1 , wherein the power supply control unit includes means for performing control to switch a power supply to a corresponding supply destination between the main power supply and the power storage device during the operation in the third mode. The image forming apparatus according to claim 1 or 2,
An image forming apparatus using an electric double layer capacitor for the power storage device. The image forming apparatus according to any one of claims 1 to 3,
The supply destination at the time of operation of the third mode that receives power supply from the power storage device is at least one of means for generating a signal for returning to the first mode and network monitoring means. An image forming apparatus. The image forming apparatus according to claim 1,
Prior to shifting to the third mode, the charge / discharge control unit performs charge control of the power storage device. A first mode in which image formation is performed by stopping / switching a power source from a power source unit including a power source connected to a commercial power source and a power storage device that is charged by the main power source and capable of charge / discharge control. A discharge control step for discharging the electric charge of the power storage device during operation in each of the second mode in which the first mode can be immediately shifted to and the third mode in which power is supplied only to some devices; ,
The power supply to the supply destination during the operation in the third mode is switched between the main power supply and the power storage device, and at least the charge / discharge control unit of the power storage device is supplied from the power storage device during the operation in the third mode. A power control process for switching to supply power to
A step of stopping power supply to the charge / discharge control unit when all the charges charged in the power storage device are discharged during the operation of the third mode;
Power supply control method characterized by having a. In the power supply control method according to claim 6 ,
A power supply control method comprising a charge control step of charging the power storage device, which is performed prior to the transition to the third mode . A program for causing a computer to function as means for executing each step in the power supply control method according to claim 6 or 7 .

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