JP4956169B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus having a capacitor.

  In an image forming apparatus such as a copying machine, an electrophotographic system is often adopted because of high speed image formation, image quality, cost, and the like. The electrophotographic method is a method in which a toner image is formed on a recording medium, and the formed toner image is fixed on the recording medium with heat and pressure. As the fixing method, the heat roller method is currently most frequently used from the viewpoint of safety and the like. In the heat roller system, a heat roller heated by a heat generating member such as a halogen heater and a pressure roller disposed opposite to the heat roller are pressed to form a mutual pressure contact portion called a nip portion. The toner is fixed to the recording medium by heating and pressurizing through the recording medium having the toner image transferred to the nip portion.

  In recent years, environmental problems have become important, and energy saving is also progressing in image forming apparatuses such as copying machines and printers. In considering the energy saving of this image forming apparatus, what cannot be ignored is the power consumption of the fixing device for fixing the toner to the recording medium. In order to reduce the power consumption of the fixing device when the image forming apparatus is not performing image formation, the temperature of the heating roller is kept at a constant temperature slightly lower than the fixable temperature during standby and an image forming instruction is received. Many methods are used that immediately raise the temperature to the fixable temperature. In the case of this method, a certain amount of power must be supplied even when the fixing device is not used, thereby consuming extra energy. This standby energy consumption is said to correspond to approximately 70% to 80% of the energy consumption of the devices constituting the image forming apparatus.

  Therefore, it has been desired to reduce energy consumption during standby and to further save power. Further, there is a demand for zero power supply when the image forming apparatus is not used. However, since the heat roller of the fixing device mainly uses a metal roller such as iron or aluminum and has a large heat capacity, if the energy consumption is reduced to zero during standby, the temperature is raised to a usable temperature (about 180 ° C.). Requires a long heating time of several minutes to several tens of minutes. Such a waiting time deteriorates the usability of the user, so that a heating method that consumes as little power as possible while rapidly rising from the standby state is desired.

  In order to shorten the heating time of the heating roller, the input energy per unit time, that is, the rated power may be increased. Actually, there is a limit to the power that can be supplied, and in order to supply a larger amount of power, it is necessary to perform special work on the power supply-related equipment, so this is not a very general solution.

  That is, even if the temperature of the heating roller is increased in a short time, the maximum input energy is determined by the power supply capacity.

In order to improve this, an image forming apparatus provided with a secondary battery capable of storing electricity as an auxiliary power source has been considered. In this image forming apparatus, the secondary battery is charged during standby of the fixing device, and when the fixing device is started up, power is supplied from the main power supply device and the secondary battery or primary battery to shorten the startup time. (For example, refer to Patent Document 1).
JP-A-10-010913

  In general, lead-acid batteries, nickel-cadmium batteries, and nickel-metal hydride batteries are used as secondary batteries. In such a secondary battery, the chargeable capacity decreases when charging and discharging are repeated. In addition, the life is shortened as the discharge is performed with a large current.

  Therefore, the more the number of times the fixing device is started up, the more charge / discharge is repeated. As a result, the deterioration of the secondary battery is accelerated, and the replacement frequency of the secondary battery is increased. Replacing the secondary battery is time consuming and increases the running cost of the replacement battery.

  An object of the present invention is to provide an image forming apparatus capable of extending the life of a power storage device when a power storage device such as a secondary battery is used.

In order to achieve the above object, an image forming apparatus according to the present invention includes a first function for forming an image received by facsimile and a second function for forming an image other than the image received by facsimile. an image forming unit for forming a toner image on a fixing unit for fixing the toner image on the sheet, and supplies main power supply circuit for operation of the image forming apparatus of power supplied from a commercial power source, the main Auxiliary power supply circuit for accumulating electric power supplied from the power supply circuit and supplying it for the operation of the image forming apparatus, an electric storage mode for accumulating the auxiliary power supply circuit, and a discharge for discharging electric power charged in the auxiliary power supply circuit A switching circuit for switching between modes, and when forming an image with the first function, the auxiliary power circuit is not operated in the discharge mode, and the power from the main power circuit is The switching circuit is controlled so as to supply power to the fixing device, and when the image is formed by the second function, the auxiliary power circuit is operated in the discharge mode, and the power from the main power circuit and the auxiliary power circuit And a control unit for controlling the switching circuit so as to supply power from the fixing unit to the fixing device.

  According to the image forming apparatus of the present invention, it is possible to provide an image forming apparatus having a long life of the power storage device by appropriately performing the number of repetitions of power storage and discharge in the power storage device as compared with the conventional case.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 is a block diagram illustrating the configuration of a multifunction image forming apparatus to which the present invention is applicable. The image forming apparatus 1 has a facsimile function, a copy function, and a printer function. The image forming apparatus 1 and the host computer 13 are configured to communicate with each other via a bidirectional communication interface 18.

  In the figure, reference numeral 2 denotes a communication line, which is a line for facsimile communication, and the transmission control unit 3 performs transmission procedures and communication control for facsimile transmission / reception.

  The facsimile function unit 4 has a function of compressing and converting image data read by the image input unit 10 for facsimile transmission, and expanding and converting facsimile data sent from the communication line 2.

  A data transmission / reception unit 9 performs communication control for receiving print image data from the host computer 13 and also has a function of controlling transmission of status information and identification information of the image forming apparatus 1. A printer function unit 5 has functions for analyzing drawing data sent from the host computer 13 and for developing drawing data into bitmap data.

  Reference numeral 6 denotes a copy function unit having a function of converting resolution or processing data read by the image input unit 10. Reference numeral 7 denotes an operation panel unit, which is provided with switches (keys) for operation, an LED display, an LCD display, a touch panel, etc., and selection of each function unit (4, 5, 6) and setting for each function. Used to do

  An image forming unit 11 has a function of forming an image on a recording sheet based on image data generated by each functional unit. The image forming unit 11 includes various components for performing image formation by a known electrophotographic method.

  An image output control unit 8 has a function of controlling the image forming apparatus 1 overall. The image output control unit 8 realizes the function processing of each function unit (4, 5, 6) based on information set by the user on the operation panel unit 7. The image output control unit 8 transfers the image data generated by each function unit to the image output unit 11 via the storage unit 12, and reads the data read by the image input unit 10 via the storage unit 12. Or transfer it to the department.

  Further, the image output control unit 8 transfers the data generated in each function unit to the host computer 13 based on various commands from each function unit, the operation panel unit 7, the image input unit 10, and the data transmission / reception unit 9. It also has a function to Note that the above functional units, control units, and the like are collectively controlled by a CPU (not shown).

  A power supply unit 20 supplies power to the entire image forming apparatus 1.

  The host computer 13 is a general computer system. The data transmission / reception unit 14 is an interface for bidirectional communication, and is connected to the image forming apparatus 1 via the bidirectional communication line 18. The data transmission / reception unit 14 transmits printer data to the image forming apparatus 1 and receives data from the image forming apparatus 1.

  A user interface unit 15 includes data input devices such as a keyboard and a pointing device, and a display device. Reference numeral 17 denotes a storage unit including a RAM, ROM, and hard disk for storing a boot program, various application programs, font data, user files, and the like. The storage unit 17 is used not only to store a control program for the entire image forming apparatus 1 but also to store identification information, print or output data received from the image forming apparatus 1.

  A system control unit 16 controls the above-described functional units (14, 15, and 17) and the entire host computer 3 (various device groups connected to a system bus (not shown)).

  FIG. 2 is a schematic configuration diagram of an image forming apparatus to which the present invention can be applied. The image forming apparatus of this example uses a laser beam printer utilizing an electrophotographic process, and has a copy function, a facsimile transmission / reception function, and a printer function.

  Reference numeral 40 denotes an image reading unit (corresponding to the image input unit 10 in FIG. 1). The image reading unit 40 illuminates the document O placed on the document table with the light source 40a and forms an image of the reflected light from the document O on the CCD 40c via the optical system 40b. (Image signal).

  Reference numeral 50 denotes an image forming unit (corresponding to the image forming unit 11 in FIG. 1). An electrophotographic photosensitive member 51 (hereinafter referred to as a photosensitive drum) is rotationally driven in the clockwise direction indicated by an arrow at a predetermined peripheral speed (process speed), and is uniformly charged by the primary charger 52 during the rotation process. The

  A laser beam scanner 53 irradiates a laser beam L modulated based on an image signal from the image reading unit 40, scans and exposes the surface of the uniformly charged photosensitive drum 51, and outputs a static image corresponding to the image information. An electrostatic latent image is formed.

  A developing unit 54 reversely develops the latent image with toner (toner adheres to the laser-exposed light potential portion of the photosensitive drum surface), and visualizes it as a toner image T.

  A transfer drum 55 is applied with a transfer bias having a polarity opposite to that of the toner. The recording material P fed from the paper feed cassette C is fed to the press-contact nip portion (transfer portion) m between the transfer roller 55 and the photosensitive drum 51 at an appropriate timing synchronized with the rotation of the photosensitive drum 51. . Then, the toner image T on the photosensitive drum 51 surface side is transferred onto the recording material P surface by applying a transfer bias.

  The recording material P to which the toner image T has been transferred is separated from the surface of the rotary photosensitive drum 51 and conveyed to the fixing device R. The fixing device R fixes the toner image T to the recording material P. Thereafter, the recording paper P is discharged out of the apparatus as an image formed product.

  If the image formation is not performed for a predetermined time after the recording material P is discharged, the image output control unit 8 supplies power to the fixing unit R, the control unit of the image forming unit, and the like until the next image formation is instructed. Is stopped or reduced to put the image forming apparatus 1 in a power saving state.

  FIG. 3 is a schematic configuration diagram showing a power supply system of the power supply unit 20 of FIG.

  In FIG. 1, reference numeral 101 denotes a main power supply circuit that supplies power for the entire image forming apparatus 1. Reference numeral 102 denotes an auxiliary power source that supplies power to the fixing device driving circuit together with the main power supply circuit 101 when the temperature of the fixing device does not reach the fixing possible temperature, such as when the image forming apparatus 1 is started up or returned from the power saving state It is a storage battery that becomes a circuit. Reference numeral 103 denotes a charging circuit for charging the storage battery 102. The storage battery 102 is configured to store electric power by an electrochemical means such as an electric double-layer capacitor.

  Reference numeral 104 combines the power from the main power supply circuit 101 and the power from the storage battery 102 and supplies the combined power to the fixing device driving circuit 105 or fixes the power from the main power supply circuit 101 without power from the storage battery 102. It is a switching circuit for switching whether to supply to the device drive circuit 105. Further, when the switching circuit 104 supplies the power from the main power supply circuit 101 to the fixing device driving circuit 105 without the power from the storage battery 102, the power from the main power supply circuit 101 is also supplied to the charger 102. The above elements 101 to 104 mainly constitute the power supply unit 20.

  Reference numeral 105 denotes a fixing device driving circuit that receives power from the switching circuit and drives the fixing device. Reference numeral 106 denotes a load other than the fixing unit and its drive circuit. The loads other than the fixing device include various chargers and exposure units necessary for the electrophotographic process, a photosensitive drum driving unit, a recording material conveying unit, and the like. 110 represents a commercial power source.

  A state in which the switching circuit 104 supplies the power of the storage battery 102 to the fixing device driving circuit 105 is referred to as a discharge mode. A state in which the switching circuit 104 does not supply the power of the battery 102 to the fixing device driving circuit 105 and supplies the power from the main power supply circuit 101 to the charging circuit 103 is also referred to as a power storage mode. In the storage mode, the charging circuit 103 charges the storage battery 102 with power from the main power supply circuit 101. That is, the switching circuit 104 has a function of switching the storage battery 102 to one of a discharge mode and a storage mode. It is assumed that charging to the storage battery 102 and discharging from the storage battery 102 do not operate simultaneously.

  In this image forming apparatus 1, it is possible to set a mode for printing an image received by the facsimile function unit 4 in advance. Specifically, the storage battery 102 is operated in the storage mode at the time of FAX reception, and the storage battery 102 is set to operate in the discharge mode at other times (such as when the copy function is executed), or an image regardless of whether the FAX reception is performed. At the time of formation, it is possible to select whether to set the storage battery 102 to operate in the discharge mode. This setting is performed based on a manual setting on the operation panel unit 7, and the operation panel unit 7 corresponds to a function setting unit.

  Further, in this image forming apparatus 1, it is possible to set a time range (time range) in which the storage battery 102 is always operated in the power storage mode at the time of image formation, regardless of the setting at the time of FAX reception. The timer is set by the operation panel unit 7, and the operation panel unit 7 corresponds to a time range setting unit.

  Note that these two settings are performed when necessary in a standby state in which image formation is not performed.

  FIG. 4 is a flowchart showing the control of the image output control unit 8 when canceling the power saving mode in this embodiment.

  The control unit 8 determines whether or not the cause of the cancellation of the power saving state of the image forming apparatus 1 is an image formation start instruction (image formation signal) (step 101).

  If the cause of the cancellation of the power saving state is the input of the image formation start instruction signal, the control unit 8 first determines whether or not the current time is within the time range set by the timer set in advance on the operation panel unit 7 ( Step 102). If it is within the set time range, the battery 102 waits until the temperature of the fixing device reaches a fixable temperature while maintaining the storage mode (steps 106 and 107). If the timer is not set or the current time is out of the set time range, the control unit 8 determines whether the storage battery 102 is set to be in the charging mode at the time of facsimile image formation (step 103). When determining that the setting has not been made, the control unit 8 shifts the storage battery 102 to the discharge mode and waits until the temperature of the fixing device reaches the fixing possible temperature (steps 105 and 107).

  Further, when the cause of the cancellation of the power saving state is not the input of the image formation start signal, the control unit 8 shifts the storage battery 102 to the discharge mode (step 105). Note that causes other than the input of the image formation start signal include turning on the image forming apparatus 1 again, operating a key for canceling the power saving state, and performing a key operation for copying.

  If the control unit 8 determines in step 108 that the operation mode in the power storage mode is set at the time of FAX reception, the control unit 8 determines whether or not an image to be formed is an image received by the facsimile function (step 104). . If the image is received by the facsimile function, the control unit 8 holds the storage battery 102 in the power storage mode ((Step 106). In addition to the image received by the facsimile function (formation of the image received by the printer function). If there is, the storage battery 102 is switched to the discharge mode (step 105).

  The controller 8 determines whether or not the temperature of the fixing device has reached the fixable temperature (step 107), and starts the image forming operation when the temperature of the fixing device reaches the fixable temperature (step 108). The control unit 8 determines whether or not there is a next image forming job (step 109). If there is no next image forming job, an image forming end operation such as a post-rotation operation of the image forming unit is performed (step 110). ). The controller 8 determines whether the storage battery 102 is in the discharge mode or the storage mode during the end operation (step 111). If the storage battery 102 is in the power storage mode, the control unit 8 maintains the state as it is. If the storage battery 102 is in the discharge mode, the control unit 8 shifts to the power storage mode and ends the image formation end operation (steps 112 and 113).

  If image formation is not started for a certain period of time after the image forming operation is completed, the image forming apparatus 1 again enters a power saving state.

  According to the first embodiment, when an image of a facsimile received document is formed, the power from the capacitor 102 is used at the time of image formation even if the time required for image formation (including the time until the start of image formation) is somewhat longer. Without supplying power from the main power supply circuit to the fixing unit. Thereby, the switching frequency of charging / discharging of the storage battery 102 can be decreased, and the lifetime of the storage battery 102 can be extended.

(Second Embodiment)
In the second embodiment, an operation when the brightness of the installation place of the image forming apparatus 1 is not more than a predetermined brightness will be described.

  FIG. 5 is a schematic diagram of the overall configuration of the image forming apparatus according to the second embodiment.

  In addition to the configuration of FIG. 2 described in the first embodiment, the configuration of the image forming apparatus 1 is the illuminance at the place where the image forming apparatus 1 is installed (in this example, the illuminance of the upper surface portion of the image forming apparatus 1). An illuminance sensor 60 (illuminance detection means) for measurement is provided. The light receiving portion of the illuminance sensor 60 is configured by a silicon photodiode method, and the measurable range is 0 to 1999 lux (lux) and the resolution is 1 lux. Assume that the output signal of the illuminance sensor 60 is sent to the image output control unit 8 of FIG.

  In the image forming apparatus according to the second embodiment, the operation mode of the storage battery 102 can be set according to the illuminance detected by the illuminance sensor 60. Specifically, when the detected illuminance is less than or equal to a predetermined illuminance, the storage battery 102 is set to operate in the storage mode, and when the detected illuminance is not less than or equal to the predetermined illuminance, it is set to operate in the discharge mode or regardless of the detected illuminance during image formation. It is possible to select whether or not to always operate in the discharge mode. This selection is performed based on manual setting in the panel unit 7, and the operation panel unit 7 corresponds to a function setting unit.

  In the image forming apparatus according to the second embodiment, the first setting and the second setting of the timer can be performed. The first setting of the timer is a time range in which the storage battery 102 is operated in the power storage mode at the time of image formation regardless of whether or not FAX reception is performed.

  The second setting of the timer is a time range in which the function of operating the storage battery 102 in the power storage mode when the illuminance detected by the illuminance sensor 60 is less than or equal to a predetermined brightness. The first and second timer settings are performed on the operation panel unit 7, and the operation panel unit 7 corresponds to a time range setting unit.

  FIG. 6 is a flowchart showing the control of the image output control unit 8 when canceling the power saving mode in this embodiment.

  The control unit 8 determines whether or not the cause of the cancellation of the power saving state of the image forming apparatus 1 is an image formation start instruction (image formation signal) (step 201).

  If the cause of the cancellation of the power saving state is the input of the image formation start instruction signal, the control unit 8 first determines whether or not the current time is within the time range set by the first setting of the timer (step 202). ). If it is within the set time range, the control unit 8 waits until the temperature of the fixing device reaches a fixable temperature while the storage battery 102 is held in the power storage mode (steps 207 and 208). When the first setting of the timer is not performed or the current time is not within the set time range, the control unit 8 determines whether the setting of the mode of the storage battery 102 is set according to the value of the detected illuminance. (Step 203). If the control unit 8 determines that it is not set in step 203, the control unit 8 operates the storage battery 102 in the discharge mode and waits until the temperature of the fixing device reaches a fixable temperature (steps 206 and 208).

  When determining that the time is set in step 203, the control unit 8 determines whether or not the current time is within the set time of the timer setting 2 (step 204). When it is determined that the current time is within the set time, the control unit 8 determines whether the illuminance detected by the illuminance sensor 60 is equal to or less than a predetermined value (here, 75 lux) (step 205). If the detected illuminance is less than or equal to the predetermined value, the control unit 8 waits until the temperature of the fixing device reaches a fixable temperature while keeping the storage battery 102 in the power storage mode (steps 207 and 208). If the detected illuminance is not less than the predetermined value, the control unit 8 causes the storage battery 102 to operate in the discharge mode and waits until the temperature of the fixing device reaches the fixable temperature (steps 206 and 208).

  In step 204, if the current time is not within the timer setting 2 time range, the control unit 8 operates the storage battery 102 in the discharge mode and waits until the temperature of the fixing device reaches the fixable temperature (step 206, 208).

  If the cause of the cancellation of the power saving state is not the input of the image formation start signal in step 201, the control unit 8 shifts the storage battery 102 to the discharge mode (step 206). Note that causes other than the input of the image formation start signal include turning on the image forming apparatus 1 again, operating a key for canceling the power saving state, and performing a key operation for copying.

  The control unit 8 determines whether or not the temperature of the fixing device has reached the fixable temperature (step 208), and when the temperature of the fixing device reaches the fixable temperature, starts the image forming operation (step 209). The controller 8 determines whether there is a next image forming job (step 210). If there is no next image forming job, the control unit 8 performs an image forming end operation such as a post-rotation operation of the image forming unit (step 211). During the end operation, the storage battery 102 is in the discharge mode or the power storage mode. Is determined (step 212). If it is in the power storage mode, the control unit 8 maintains the power storage mode. If it is in the discharge mode, the control unit 8 shifts to the power storage mode and ends the image formation end operation (steps 213 and 214).

  According to the second embodiment, when it can be determined that the illuminance around the image forming apparatus is dark, it can be determined that there is no person near the apparatus, and the capacitor is used during image formation even if the time required for image formation is somewhat longer. The power from the main power supply circuit is supplied to the fixing unit without using the power from 102. Thereby, the switching frequency of charging / discharging of the storage battery 102 can be reduced, and a lifetime can be extended.

(Third embodiment)
In the third embodiment, an operation when no person is present around the image forming apparatus will be described.

  FIG. 7 is a schematic diagram of the overall configuration of the image forming apparatus according to the third embodiment.

  In addition to the configuration of the image forming apparatus in the third embodiment described in FIG. 2 of the first embodiment, sensors 60a, 60b, 60c, and 60d (human body detecting means) that detect the human body in the vicinity of the image forming apparatus. Equipped on the front and both sides of the image forming apparatus. These sensors are human body detection sensors using a Fresnel lens with a viewing angle of 80 ° and a viewing distance of 2 mm and a pyroelectric infrared sensor. If at least one of these detects a human body, the control unit 8 determines that there is a person near the image forming apparatus. It is assumed that the output signals of the sensors 60a, 60b, 60c, 60d are sent to the image output control unit 8 in FIG.

  In the image forming apparatus according to the third embodiment, the storage mode and the discharge mode are switched according to the detection results of the human body detection sensors 60a, 60b, 60c, and 60d, or the storage battery is always discharged during image formation. It is possible to select whether to set to operate in the mode. This selection is performed based on manual setting on the operation panel unit 7, and the operation panel unit 7 corresponds to a function setting unit.

  In the image forming apparatus according to the third embodiment, the first setting and the second setting of the timer can be performed. The first setting of the timer is a time range in which the storage battery 102 is operated in the storage mode during image formation regardless of the detection results of the human body detection sensors 60a, 60b, 60c, and 60d.

  The second setting of the timer is a time range in which the function of operating the storage battery in the power storage mode when the detection results of the human body detection sensors 60a, 60b, 60c, and 60d are absent is in effect. The first and second timer settings are performed on the operation panel unit 7, and the operation panel unit 7 corresponds to a time range setting unit.

  FIG. 8 is a flowchart showing the control of the image output control unit 8 when canceling the power saving mode in this embodiment.

  The control unit 8 determines whether or not the cause of the cancellation of the power saving state of the image forming apparatus 1 is an image formation start instruction (image formation signal) (step 301).

  If the cause of the cancellation of the power saving state is the input of the image formation start instruction signal, the control unit 8 first determines whether or not the current time is within the time range set by the first setting of the timer (step) 302). If it is within the set time range, the control unit 8 waits until the temperature of the fixing device reaches a fixable temperature while the storage battery 102 is held in the power storage mode (steps 307 and 308). When the first setting of the timer is not performed or the current time is not within the set time range, the control unit 8 determines whether the setting for switching the operation mode of the storage battery 102 is made according to the result of human body detection. (Step 303). If the control unit 8 determines that it is not set in step 303, the control unit 8 operates the storage battery 102 in the discharge mode and waits until the temperature of the fixing device reaches a fixable temperature (steps 306 and 308).

  When it is determined that the setting is made in Step 303, the control unit 8 determines whether or not the current time is within the time range of the timer setting 2 (Step 304). When determining that the current time is within the set time, the control unit 8 determines whether any of the human body detection sensors 60a to 60d detects the presence of a human body (step 305). If the detection result is not a human body, the control unit 8 waits for the temperature of the fixing device to reach a fixable temperature while keeping the storage battery 102 in the power storage mode (steps 307 and 308). If the detection result is that there is a human body, the control unit 8 operates the storage battery 102 in the discharge mode and waits until the temperature of the fixing device reaches the fixing possible temperature (steps 306 and 308).

  In step 304, if the current time is not within the timer setting 2 time range, the control unit 8 operates the storage battery 102 in the discharge mode and waits until the temperature of the fixing device reaches the fixable temperature (step 306). 308).

  If the cause of the cancellation of the power saving state is not the input of the image formation start signal in step 301, the control unit 8 shifts the storage battery 102 to the discharge mode (step 306). Note that causes other than the input of the image formation start signal include turning on the image forming apparatus 1 again, operating a key for canceling the power saving state, and performing a key operation for copying.

  The control unit 8 determines whether or not the temperature of the fixing device has reached the fixable temperature (step 308), and starts the image forming operation when the temperature of the fixing device reaches the fixable temperature (step 309). The controller 8 determines whether there is a next image forming job (step 310). If there is no next image forming job, the control unit 8 performs an image forming end operation such as a post-rotation operation of the image forming unit (step 311). During the end operation, the storage battery 102 is in the discharge mode or the power storage mode. (Step 312). If it is in the power storage mode, the control unit 8 maintains the power storage mode. If it is in the discharge mode, the control unit 8 shifts to the power storage mode and ends the image formation end operation (steps 313 and 314).

  According to the third embodiment, when there is no person near the apparatus, the power from the main power supply circuit is not used at the time of image formation without using the power from the capacitor 102 even when the time required for image formation is somewhat longer. To supply power to the fuser. Thereby, the switching frequency of charging / discharging of the storage battery 102 can be reduced, and a lifetime can be extended.

  In the first to third embodiments described above, the control at the time of return from the power saving state has been described. In addition to this, when an instruction to start image formation (copy instruction, FAX reception, print instruction) is input, the temperature of the fixing device does not reach the fixable temperature, and it is necessary to heat the fixing device. The control in each embodiment can be applied. For example, the input of an image formation start instruction is waited, and if there is an input, step 102 and after in FIG. 4, step 201 and after in FIG. 6, and step 302 and after in FIG. 8 may be executed.

  Moreover, you may operate combining the control of 1st-3rd embodiment mentioned above.

1 is a block diagram illustrating a configuration of an image forming apparatus. 1 is an overall configuration schematic diagram of an image forming apparatus according to a first embodiment. It is the schematic of an electric power supply part. It is a control flowchart in a 1st embodiment. FIG. 5 is a schematic diagram illustrating an entire configuration of an image forming apparatus according to a second embodiment. It is a control flowchart in a 2nd embodiment. FIG. 10 is a schematic diagram illustrating an entire configuration of an image forming apparatus according to a third embodiment. It is a control flowchart in a 3rd embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 4 Facsimile function part 8 Image output control part 20 Electric power supply part 101 Main power supply circuit 102 Storage battery 105 Fixing device drive circuit

Claims (8)

In an image forming apparatus having a first function of forming an image received by facsimile and a second function of forming an image other than an image received by facsimile,
An image forming unit for forming a toner image on a sheet;
A fixing device for fixing the toner image to the sheet;
A main power supply circuit for supplying power supplied from a commercial power supply for the operation of the image forming apparatus;
An auxiliary power supply circuit that stores electric power supplied from the main power supply circuit and supplies the electric power for the operation of the image forming apparatus;
A switching circuit for switching between a storage mode for storing the auxiliary power supply circuit and a discharge mode for discharging power charged in the auxiliary power supply circuit;
When forming an image with the first function, the switching circuit is controlled to supply power from the main power supply circuit to the fixing device without operating the auxiliary power supply circuit in the discharge mode, and the second When the image is formed by the function, the auxiliary power circuit is operated in the discharge mode, and the switching circuit is controlled to supply the power from the main power circuit and the power from the auxiliary power circuit to the fixing device. A control unit;
An image forming apparatus comprising: The image forming apparatus according to claim 1, characterized in that it has a time range setting means for setting a time range for operating the auxiliary power supply circuit in the electric storage mode when the image formation start instruction is input. Wherein the auxiliary image forming apparatus according to claim 1, characterized in that it comprises a function setting unit configured to set whether the power supply circuit to enable the function to operate in a power storage mode when imaged with the first function . When the image forming apparatus does not perform image formation for a predetermined time, the image forming apparatus further includes a control unit that shifts the image forming apparatus to a power saving state, and the power saving state is canceled to form an image by the first function. The control unit controls the switching circuit to operate the auxiliary power supply circuit in the power storage mode and supply power from the main power supply circuit to the fixing device, and forms an image by the second function. When the power saving state for canceling is released, the control unit operates the auxiliary power supply circuit in the discharge mode, and supplies the power from the main power supply circuit and the power from the auxiliary power supply circuit to the fixing device. 2. The image forming apparatus according to claim 1, wherein the switching circuit is controlled so as to be supplied to the image forming apparatus. A controller that shifts the image forming apparatus to a power saving state when the image forming apparatus does not perform image formation for a predetermined time;
Illuminance detection means for detecting the illuminance of the place where the image forming apparatus is installed;
Further comprising a, wherein, when the power saving state is released, when the illuminance sensed by the illuminance detecting means is below a predetermined illuminance, to operate the auxiliary power supply circuit in the power storage mode, the The switching circuit is controlled to supply power from a main power supply circuit to the fixing device, and when the illuminance detected by the illuminance detection means is not less than or equal to the predetermined illuminance, the auxiliary power supply is operated in the discharge mode, The image forming apparatus according to claim 1, wherein the switching circuit is controlled to supply power from a main power supply circuit and power from the auxiliary power supply circuit to the dressing device. 6. The apparatus according to claim 5, further comprising: a function setting unit that sets whether to enable a function of operating the auxiliary power supply circuit in a power storage mode when the illuminance detected by the illuminance detection unit is equal to or lower than a predetermined illuminance. The image forming apparatus described. A controller that shifts the image forming apparatus to a power saving state when the image forming apparatus does not perform image formation for a predetermined time;
Human body detecting means for detecting whether or not there is a person around the image forming apparatus;
Further comprising a, wherein, when the power saving state is released, if it there are people not detected by the human body detecting means, to operate the auxiliary power supply circuit in the power storage mode, the The switching circuit is controlled to supply power from a main power supply circuit to the fixing device, and when the human body detecting means detects that there is a person, the auxiliary power supply is operated in the discharge mode, and the main power supply The image forming apparatus according to claim 1, wherein the switching circuit is controlled to supply power from a circuit and power from the auxiliary power supply circuit to the fixing device. 8. The apparatus according to claim 7, further comprising a function setting unit configured to set whether to enable a function of operating the auxiliary power supply circuit in a power storage mode when it is not detected by the human body detection unit. The image forming apparatus described.

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