JP4723286B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus having a fixing unit that fixes toner onto a recording sheet by heat.

  An image forming apparatus such as a copier heats the fixing heater using electric power from a commercial power source, and has an energy saving mode for waiting for a print instruction in a state where power supply to the fixing heater is stopped as an energy saving measure. There is something. In an image forming apparatus having an energy saving mode, the temperature of the fixing heater once the power supply has been stopped falls below a temperature at which fixing can be performed. Therefore, when returning from the energy saving mode to the printing mode, the temperature of the fixing heater is reduced. A waiting time (rise time) until reaching a predetermined temperature is required.

  Here, if a large amount of electric power is used to return to the print mode, the temperature of the fixing heater can be rapidly increased. However, the commercial power source in Japan is 1500 W at 100 V and 15 A, which is the maximum. There is a limit to shortening the temperature rise time. Therefore, for example, as shown in Patent Document 1 below, in order to shorten the rise time, a chargeable auxiliary power source (capacitor or battery) is provided, and in the energy saving mode, the auxiliary power source is charged by a commercial power source. When returning to the print mode, there has been proposed an image forming apparatus that shortens the rise time by flowing a large current to the fixing heater using both a commercial power supply and an auxiliary power supply.

  Further, in the conventional image forming apparatus, when printing is performed for a long time, a large amount of recording paper is carried into the nip portion of the fixing roller, so that the heat of the fixing roller is taken away by the recording paper and printing is performed. The temperature of the fixing roller may drop.

  Here, the characteristics of the electric double layer capacitor suitable for the capacitor as the auxiliary power source and the lithium ion battery suitable for the battery as the auxiliary power source will be described. The electric double layer capacitor is characterized in that it can be charged / discharged with a large current and has a relatively long charge / discharge life (for example, on the order of several hundred thousand times), but the voltage drops rapidly. Therefore, in order to supply power for a long time, it is necessary to increase the capacity, which is expensive.

A lithium ion battery has a feature that a decrease in voltage until the end of discharge is small. Therefore, it is possible to supply electric power for a long time at a lower cost compared with the electric double layer capacitor. Moreover, a lithium ion battery has the property that a lifetime becomes short, so that charging / discharging is repeated with a large electric current. When the halogen heater used for the fixing heater is lit from a state cooled to about room temperature, a large inrush current flows to the halogen heater and a current nearly 10 times the rated current may flow. In the case where it is carried out, the life of the repeated number of times of charging and discharging of the lithium ion battery is relatively short, about 500 to 1000 times.
Japanese Patent Laid-Open No. 10-282821

  To reduce the rise time from the energy saving mode to the printing mode and to prevent the temperature of the fixing heater from dropping during printing, use the auxiliary power supply to print from the return to the printing mode from the energy saving mode. A large current may be supplied to the fixing heater over a long period until completion. However, since the electric double layer capacitor has a feature that the voltage decreases rapidly from the start of discharge, when the electric double layer capacitor is used as an auxiliary power source, it must be made to withstand long-time use, and therefore If the capacity of the electric double layer capacitor is increased, the electric double layer capacitor becomes expensive.

  In addition, the halogen heater used in the fixing roller has a property that a large current flows when it is lit from a temperature cooled to near room temperature. Therefore, when a lithium ion battery is used as an auxiliary power source, charging / discharging is performed with a large current. Therefore, there is a problem that the life of the lithium ion battery is shortened.

  The present invention has been made in view of the above problems, and while reducing the time required to raise the temperature of the fixing unit to the fixable temperature, it is possible to eliminate the drop in the fixing temperature during printing, In addition, an object is to provide an image forming apparatus that has a long life of an auxiliary power source and is inexpensive.

An image forming apparatus according to claim 1 includes an auxiliary power source including a capacitor;
A secondary battery as a power source for charging the capacitor;
A first fixing heater that heats a fixing unit that fixes toner onto a recording sheet with electric power from the auxiliary power source;
A second fixing heater for heating the fixing unit with electric power from an external power source when a main power switch of the image forming apparatus is in an on state;
Switching means for switching between charging the secondary battery with power from the external power source or discharging the power of the secondary battery to charge the auxiliary power source;
State determining means for determining whether the main power switch is in an on state or an off state;
When the state determining means determines that the main power switch is in the on state, the switching means is switched to the side to discharge the secondary battery, and the main power switch is in the off state by the state determining means. When it is determined that there is an image forming apparatus, the image forming apparatus includes a control unit that switches the switching unit to a side where the secondary battery is charged by the external power source.

  In this configuration, when the state determination unit determines that the main power switch of the image forming apparatus is in the ON state, the control unit sets the switching unit so that the auxiliary power is charged with the power from the secondary battery. When it is determined by the switching and state determination means that the main power switch is in the OFF state, the control means switches the switching means so that the secondary battery is charged with power from the external power supply.

An image forming apparatus according to a second aspect is the image forming apparatus according to the first aspect, wherein first fixing heater driving means for switching whether or not to drive the first fixing heater;
A second fixing heater driving means for switching whether to drive the second fixing heater with electric power from the external power source;
The state determination means is in a heater-on state in which the first and second fixing heaters are driven by the first and second fixing heater driving means when the main power switch is in an on-state, or the first And further determining whether or not the first and second fixing heaters are stopped by the second fixing heater driving means.
Wherein, when the main power switch is determined that the on state by said state judgment means, only, to charge the auxiliary power supply to discharge the rechargeable battery when it is determined that the heater ON state When the switching means is switched to the side and the heater is turned off , the switching means is switched to the side where the secondary battery is charged by the external power source .

  In this configuration, even when it is determined that the main power switch is in the on state, only when the first fixing heater is in the heater on state, the control unit switches the switching unit and the secondary battery uses the auxiliary power source. When the first fixing heater is in the heater-off state, the switching unit is switched so that the secondary battery is charged with the electric power from the external power source.

  An image forming apparatus according to a third aspect is the image forming apparatus according to the first or second aspect, wherein the switching unit is in a state where no power is supplied to the image forming apparatus. The auxiliary power source is switched to the charging side.

  In this configuration, when power is not supplied to the image forming apparatus, for example, when the power outlet of the image forming apparatus is disconnected from the external power source, the auxiliary power is charged by the secondary battery. The temperature of the fixing unit can be raised to the required temperature in a short time by the power from the auxiliary power supply when printing is performed by the image forming apparatus next time.

An image forming apparatus according to a fourth aspect of the present invention is the image forming apparatus according to any one of the first to third aspects, wherein a time zone determining means for determining whether or not it is a midnight power time zone,
Further comprising power supply switching means for switching whether to supply power from the external power source to the secondary battery,
When the state determining unit determines that the main power switch is in an OFF state and the time zone determining unit determines that the current time is a midnight power time zone, the control unit The supply switching means is switched to the side where the power from the external power source is supplied to the secondary battery, the state determining means determines that the switch is off, and the time zone determining means determines that the current time is midnight. When it is determined that it is not in the power time zone, the power supply switching means is switched to the side where the power from the external power source is not supplied to the secondary battery.

  In this configuration, even when the state determination unit determines that the state of the image forming apparatus is that the main power switch is in the off state, the current time is a midnight power time zone where the electricity rate is low by the time zone determination unit. If it is not determined that the secondary battery is not charged, the secondary battery is not charged, and the electricity charge required for charging the secondary battery is kept low.

An image forming apparatus according to claim 5 is the image forming apparatus according to claim 4, further comprising a charge degree determining unit that determines whether or not the secondary battery is fully charged.
Even if the control means determines that the switch-off state is determined by the state determination means, and the time zone determination means determines that the current time is a midnight power time zone, When it is determined by the determining means that the secondary battery is fully charged, the power supply switching means is switched to the side where the power from the external power source is not supplied to the secondary battery.

  In this configuration, when it is determined that the secondary battery is fully charged by the charge level determination unit, the control unit sets the power supply switching unit to the side where the power from the external power source is not supplied to the secondary battery. By switching, overcharge is prevented and the burden on the secondary battery is reduced.

  An image forming apparatus according to a sixth aspect is the image forming apparatus according to the fifth aspect, wherein the control unit is configured to determine whether the state of the image forming apparatus is the main power switch by the state determining unit. When it is determined that the battery is in an off state and the secondary battery is not fully charged by the charge level determination unit, the current time is not a midnight power time zone by the time zone determination unit. Even if it is discriminated, the power supply switching means is switched to the side where power from the external power source is supplied to the secondary battery.

  In this configuration, when it is determined that the secondary battery is not fully charged by the charge level determination unit, the control unit is configured even if it is determined by the time zone determination unit that the current time is not a midnight power time zone. The power supply switching means is switched to the side where the electric power from the external power source is supplied to the secondary battery so that the charging of the secondary battery, that is, the performance of the image forming apparatus is more important than the reduction of the electricity bill. Yes.

An image forming apparatus according to a seventh aspect is the image forming apparatus according to the fifth aspect, further comprising setting accepting means for accepting a setting by a user as to whether or not to charge the secondary battery.
The control means determines that the secondary battery is fully charged by the charge degree determination means when the state determination means determines that the state of the image forming apparatus is the main power switch is OFF. In the case where it is determined that there is no power and the setting accepting unit accepts the setting that the charging is performed, this is a case where the time zone discriminating unit determines that the current time is not a midnight power time zone. However, the power supply switching means is switched to the side where the power from the external power source is supplied to the secondary battery.

  In this configuration, if the setting acceptance unit accepts the setting to perform the charging, the control unit determines the degree of charge even if the current time is determined not to be in the midnight power time zone by the time zone discrimination unit. When it is determined that the secondary battery is not fully charged, the power supply switching means is switched to the side where the power from the external power source is supplied to the secondary battery. Thus, whether or not to charge the secondary battery in a time zone other than the midnight power time zone can be changed according to an instruction from the user.

  According to the first aspect of the invention, when the main power switch of the image forming apparatus is on, the first fixing heater is heated by the power from the auxiliary power source in addition to the second fixing heater. It is possible to shorten the waiting time (rise time) until the temperature of the fixing unit reaches a temperature capable of fixing. For this reason, the heaters of the fixing unit can be turned off at the time of printing standby, so that significant power saving can be achieved. Further, during the fixing operation, even if the temperature of the fixing unit is lowered due to the paper passing, the first fixing heater can perform heating to compensate for the temperature reduction.

  In addition, when the main power switch of the image forming apparatus is turned on, the auxiliary power source can be always charged with the power from the secondary battery so that the auxiliary power source can be kept fully charged. There is no problem that the power supplied to the first fixing heater is lowered due to the voltage of the power source being lowered. In addition, the secondary battery functions as a charge for the auxiliary power supply and does not function as a heating power supply for the fixing heater. Therefore, the secondary battery does not discharge with a large current, and therefore does not repeatedly charge and discharge with a large current. The life of the secondary battery can be kept long.

  According to the second aspect of the present invention, when the main power switch of the image forming apparatus is on, the secondary battery charges the auxiliary power when the heater is on, and when the heater is off, the external power source Because the secondary battery is charged with the power of, by charging the secondary battery at a timing when the secondary battery does not need to charge the auxiliary power source, and charging the power consumption up to that point, The secondary battery can be kept in a state where the auxiliary power supply can be charged.

  According to the third aspect of the present invention, when power is not supplied to the image forming apparatus, for example, even when the power outlet of the image forming apparatus is disconnected from the external power source, Keep the auxiliary power supply charged by the secondary battery, and the next time the image forming apparatus performs printing, the power from the auxiliary power supply raises the temperature of the fixing unit to the required temperature in a short time. Can do.

  According to the fourth aspect of the present invention, even if the state of the image forming apparatus is in the switch-off state, the secondary battery is not charged unless it is in the late-night power time zone where the electricity rate is low. The electricity bill required for charging can be kept low.

  According to the fifth aspect of the present invention, overcharge of the secondary battery is prevented, and the burden on the secondary battery is reduced.

  According to the sixth aspect of the present invention, if the secondary battery is not fully charged, the secondary battery is charged even when it is not in the late-night power time zone, so the performance of the image forming apparatus can be ensured. .

  According to the seventh aspect of the present invention, when the setting for accepting the charging is accepted by the setting accepting means, if the secondary battery is not fully charged, the current time is in the midnight power time zone. Since the secondary battery is charged even if it is not, whether or not to charge the secondary battery in a time zone other than the midnight power time zone can be changed according to an instruction from the user.

  Embodiments according to the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an internal configuration of a multi-function peripheral which is an embodiment of an image forming apparatus according to the present invention. In particular, a fixing heater control mechanism for controlling on / off of a fixing heater for heating a fixing roller is mainly shown. FIG. FIG. 2 shows each state type of the multifunction device 1 (plug-in state, initial startup state, print state, ready state, sleep state, and rapid startup state) and an opportunity to transition from each state to another state. This is state transition information indicating the type of event. Note that the image forming apparatus according to the present invention may be, for example, a printer, a copier, a facsimile machine, or the above-described multifunction machine having these functions. In this embodiment, the image forming apparatus according to the present invention is described by taking a multifunction peripheral as an example.

  In the multifunction machine 1, the fixing roller (not shown) nips the recording paper on which the toner image is transferred from the photosensitive drum by a heat roller and a pressure roller (not shown), and the toner image is applied to the recording paper by heat and pressure. It is to fix. The external power source 2 is a so-called commercial power source, for example, and is an AC (alternating current) power source by an electric power company. The power supply control circuit 21 controls whether or not the power from the external power supply 2 is supplied to each part of the apparatus in response to turning on or off of a main switch (main power switch) 22 that is a main power switch for starting the multifunction device 1. To do.

  The multifunction device 1 includes an image forming unit 11, an instruction receiving unit 12, a timer 13, a fixing roller temperature sensor 14, a control unit 15, a first fixing heater 17, a heater ON / OFF control circuit 18, and an electric double layer capacitor (auxiliary power source). 19, switching regulator 20, lithium ion battery (secondary battery) 23, relay switch (switching means) 24, battery charge control circuit 25 (power supply switching means), second fixing heater 26, second fixing heater drive circuit 27, and A battery remaining amount detection unit 28 is provided.

  The image forming unit 11 performs image formation for forming a toner image on recording paper. The multifunction device 1 operates in response to a print instruction when, for example, a copy function, a printer function, or a facsimile reception function is executed. . The instruction receiving unit (setting receiving unit) 12 receives various operation execution instructions from the user or the like with respect to the multifunction device 1 and receives, for example, execution instructions for a copy function, a printer function, and a facsimile reception function. In the instruction receiving unit 12, a copy function execution instruction is input to the multifunction device 1 by the user from the operation panel (not shown) of the multifunction device 1. The printer function execution instruction is transmitted to the multifunction device 1 from, for example, a PC (personal computer) connected to the multifunction device 1 via a network or the like. The facsimile reception execution instruction is transmitted to the multifunction device 1 from a facsimile transmission device connected to the multifunction device 1 through a public line or the like.

  The timer (functioning as a part of the time zone discrimination means) 13 measures the elapsed time and the current time from when the instruction is received from the state discrimination unit 152. The fixing roller temperature sensor 14 measures the temperature of the fixing roller and outputs it to the fixing roller temperature control unit 151.

  The first fixing heater 17 and the second fixing heater 26 are heaters for heating the fixing roller. In the present embodiment, the first fixing heater 17 and the second fixing heater 26 are halogen heaters. The first fixing heater 17 is a DC (direct current) heater of 1300 to 1800 W, for example, and the second fixing heater 26 is an AC (alternating current) heater of 1200 W, for example. The first fixing heater 17 uses a large power consumption in order to heat rapidly by flowing a large current. The first fixing heater 17 and the second fixing heater 26 are installed adjacent to each other.

  The electric double layer capacitor 19 functions as a power source for driving the first fixing heater 17. The electric double layer capacitor 19 can be charged and discharged with a large current. Although the electric double layer capacitor 19 has a relatively long charge / discharge life (for example, on the order of several hundred thousand times), the electric power (voltage) is rapidly reduced when the electric charge is discharged. The charging time of the electric double layer capacitor 19 is several tens of seconds, for example.

  The heater ON / OFF control circuit (first fixing heater driving means) 18 controls whether or not the first fixing heater 17 is driven by the electric power from the electric double layer capacitor 19. That is, the heater ON / OFF control circuit 18 switches and controls whether or not the first fixing heater 17 is heated by the electric power from the electric double layer capacitor 19. The switching regulator 20 is a power supply stabilization device that smoothes the voltage input from the lithium ion battery 23 and outputs a stable DC voltage to the electric double layer capacitor 19.

  The lithium ion battery 23 is a rechargeable power source that supplies power to the electric double layer capacitor 19 in order to charge the electric double layer capacitor 19. The lithium ion battery 23 is characterized by a small voltage drop until the end of discharge. The charging time of the lithium ion battery 23 is, for example, 10 minutes. The relay switch 24 connects the lithium ion battery 23 with a circuit so that the electric double layer capacitor 19 is charged with (1) power discharged from the lithium ion battery 23 or (2) the external power source 2 is connected to the power supply source. Is a switch for switching whether to connect the circuit so as to charge the lithium ion battery 23.

  The battery charge control circuit 25 is a switch that switches whether to charge the lithium ion battery 23 by switching whether to supply power from the external power source 2 to the lithium ion battery 23. The connection of the relay switch 24 is switched to the side where the lithium ion battery 23 is charged, and the battery charge control circuit 25 supplies power from the external power source 2 to the lithium ion battery 23, whereby the lithium ion battery 23 is charged. .

  The second fixing heater driving circuit (second fixing heater driving means) 27 is configured to drive the second fixing heater 26 using the external power source 2 as a power supply source, that is, whether to heat the second fixing heater 26. It functions as a switch to switch between. When the switch is turned on, the second fixing heater 26 is driven, and when the switch is turned off, the second fixing heater 26 is stopped.

  When the main switch 22 is turned off and the power plug is connected to the outlet of the external power source 2, the multi-function device 1 uses the power from the external power source 2 to connect the lithium ion battery 23 with the power from the external power source 2. The battery charging control circuit 25 is set to supply the power of the external power source 2 to the lithium ion battery 23. In addition, when the power plug is disconnected from the outlet of the external power source 2, the relay switch 24 is set to be switched to the side where the electric double layer capacitor 19 is charged with the power of the lithium ion battery 23.

  The control unit 15 controls the overall operation of the multifunction machine 1, and includes a CPU (Central Processing Unit) that executes a program, a ROM (Read Only Memory) that stores the program, and a temporary storage area when the program is executed. It is comprised from RAM (random access memory) etc. which are used as. The control unit 15 includes a fixing roller temperature control unit 151, a state determination unit 152, and a switch control unit 153.

  The state determination unit (state determination unit, time zone determination unit, charge degree determination unit) 152 is configured so that the current state of the multifunction device 1 is the initial startup state, the print state, the ready state, the sleep state, the plug-in state, And a rapid start-up state. The state determination unit 152 determines whether the multifunction device 1 has any one of the above based on the on / off state of the main switch 22 sent from the power supply control circuit 21 or the absence of a print instruction from the instruction receiving unit 12 for a predetermined time. Determine if it is in a state.

  The initial startup state is a predetermined first temperature range in which the temperature of the fixing roller can be fixed (for example, around 180 ° C., for example) from the time when the multifunction device 1 is turned on (after the main switch 22 is turned on). This is the state up to).

  The print state is a state while the multifunction device 1 is performing a printing operation (a state from when printing (including copying) is completed until it is completed). In the printing state, the temperature of the fixing roller is kept within the first temperature range.

  The ready state is a state where the input of the print instruction is waited and the fixing roller can be immediately raised to the first temperature range if there is a print instruction. In this ready state, the temperature of the fixing roller is set to a second temperature range (for example, around 90 ° C.) that is lower than the first temperature range.

  The sleep state is a state in which the first fixing heater 17 and the second fixing heater 26 are turned off to save power, and when a print instruction is not input for a certain period of time, the sleep state is shifted to the sleep state. It has become.

  The plug-in state is a state in which the power plug is inserted into the outlet of the external power source 2 but the main switch 22 is turned off.

  The rapid start-up state refers to a state in which, when a print instruction is received in the sleep state, the temperature of the fixing roller rises to the first temperature range in which the fixing roller can be fixed.

  The state determination unit 152 stores the state transition information shown in FIG. 2 in advance, and determines the current state (transition source state) and the state (transition destination state) that makes the next transition from the generated event. The state determination unit 152 determines whether the multifunction device 1 has any of the above based on the ON or OFF state of the main switch 22 sent from the power supply control circuit 9 or the absence of a print instruction from the instruction receiving unit 12 for a predetermined time. Determine if it is in a state. The state determination unit 152 sends information indicating the determined current state and the next transition state to the switch control unit 153.

  The fixing roller temperature control unit 151 drives and controls the heater ON / OFF control circuit 18 and the second fixing heater driving circuit 27 so that the temperature of the fixing roller is in the first temperature range in the printing state. The first fixing heater 17 and the second fixing heater 26 are controlled to be turned on / off. The fixing roller temperature control unit 151 controls the on / off of the second fixing heater 26 so that the temperature of the fixing roller is within a predetermined second temperature range in the ready state. Each control by the fixing roller temperature control unit 151 is performed via the switch control unit 153.

  The switch control unit (control unit) 153 is a heater ON / OFF control circuit for each current state of the multifunction machine 1 determined by the state determination unit 152 or based on an instruction from the fixing roller temperature control unit 151. 18, switching of the relay switch 24, the battery charge control circuit 25, and the second fixing heater drive circuit 27 is controlled.

  The battery remaining amount detection unit (functioning as part of the charge level determination unit) 28 detects the degree of charge (remaining battery amount) of the lithium ion battery 23 and sends the detection result to the state determination unit 152.

  FIG. 3 is a diagram illustrating states of the heater ON / OFF control circuit 18, the relay switch 24, the battery charge control circuit 25, and the second fixing heater driving circuit 27 in each state of the multifunction machine 1. Switching control of the heater ON / OFF control circuit 18, the relay switch 24, the battery charge control circuit 25, and the second fixing heater drive circuit 27 corresponding to each state of the multifunction machine 1 is performed by the switch control unit 153. Even if the switch control unit 153 stores the states of the heater ON / OFF control circuit 18, the relay switch 24, the battery charge control circuit 25, and the second fixing heater drive circuit 27 corresponding to each state of the multifunction device 1. Alternatively, it may be stored in a storage unit (not shown) and read by the switch control unit 153 as necessary. In the power supply control by the battery charge control circuit 25, the case where the power is supplied is indicated as ON, and the case where the power is not supplied is indicated as OFF.

  In the initial start-up state and the quick start-up state, the relay switch 24 is switched to the side that discharges the lithium ion battery 23 (the side that charges the electric double layer capacitor 19), and the battery charge control circuit 25 is turned off. The first fixing heater 17 is turned on by the heater ON / OFF control circuit 18, and the second fixing heater 26 is turned on by the second fixing heater driving circuit 27.

  Further, in the ready state, the first fixing heater 17 is turned off by the heater ON / OFF control circuit 18, and the relay switch 24 is switched to the side for discharging the lithium ion battery 23 (the side for charging the electric double layer capacitor 19). In this state, the battery charging control circuit 25 is turned off, and the second fixing heater 26 is turned on by the second fixing heater driving circuit 27.

  In the sleep state and the plug-in state, the first fixing heater 17 is turned off by the heater ON / OFF control circuit 18, and the relay switch 24 is switched to the side for charging the lithium ion battery 23. The battery charge control circuit 25 is turned on and the lithium ion battery 23 is charged. The second fixing heater 26 is also turned off by the second fixing heater driving circuit 27.

  In the printing state, the heater ON / OFF control circuit 18 switches on or off the first fixing heater 17 based on the temperature value of the fixing roller input from the fixing roller temperature sensor 14 to the switch control unit 153, and fixing. The temperature of the roller is maintained in the first temperature range. The battery charge control circuit 25 is turned off. The relay switch 24 is switched to the side that discharges the lithium ion battery 23 (the side that charges the electric double layer capacitor 19). The second fixing heater 26 is turned on by the second fixing heater driving circuit 27.

  Next, a circuit image of the multifunction device 1 fixing heater control mechanism according to the present invention will be described. FIG. 4 is a circuit diagram showing a circuit image (outline) of the fixing heater control mechanism.

  The external power source (AC) 2 is connected to the second fixing heater 26 via the second fixing heater driving circuit 27. The external power supply 2 is connected to the first fixing heater 17 side via a diode 41 that rectifies AC current into DC current. As a result, a DC current flows through the first fixing heater 17 and an AC current flows through the second fixing heater 26. The first fixing heater 17 and the second fixing heater 26 constitute a fixing heater 30.

  A battery charging control circuit 25, a lithium ion battery 23, a switching regulator 20, a relay switch 24, an electric double layer capacitor 19, and a heater ON / OFF control circuit 18 are connected to a circuit to which the first fixing heater 17 is connected. Yes. The current from the diode 41 is supplied to the lithium ion battery 23 via the battery charge control circuit 25. A relay switch 24 is provided between the battery charge control circuit 25 and the lithium ion battery 23, and (1) the lithium ion battery 23 is connected to the battery charge control circuit 25 side by the relay switch 24. The connection is such that the lithium ion battery 23 is charged with the electric power from the power source 2 or (2) the lithium ion battery 23 is connected to the switching regulator 20 side and the electric double layer capacitor 19 is supplied with electric power to Whether to connect the electric double layer capacitor 19 with the electric power of the ion battery 23 is switched.

  The electric double layer capacitor 19 is connected to the switching regulator 20 and is charged with electric power from the lithium ion battery 23, but is also connected to the first fixing heater 17 to supply electric power of the electric double layer capacitor 19 to the first fixing heater 17. To supply. A heater ON / OFF control circuit 18 is connected between the electric double layer capacitor 19 and the first fixing heater 17, and whether or not the first fixing heater 17 is driven by electric power from the electric double layer capacitor 19. Can be controlled.

  The circuit on the second fixing heater 26 side is connected to the external power source 2 and the second fixing heater 26, and the second fixing heater driving circuit 27 is interposed between the external power source 2 and the second fixing heater 26. The second fixing heater driving circuit 27 can control whether or not the second fixing heater 26 is driven by the electric power from the external power source 2.

  Next, a description will be given of a first embodiment regarding processing at the time of fixing heater driving control in the multifunction machine 1. FIG. 5 and FIG. 6 are flowcharts showing the first embodiment regarding the processing at the time of fixing heater driving control in the multifunction machine 1.

  In the multifunction device 1, the relay switch 24 is switched to the side that discharges the lithium ion battery 23 (the side that charges the electric double layer capacitor 19) when the power plug of the multifunction device 1 is disconnected from the outlet. The heater ON / OFF control circuit 18 turns off the first fixing heater 17, the battery charging control circuit 25 is off (the state where the power of the external power supply 2 is not supplied to the lithium ion battery 23), and the second fixing heater driving circuit 27 is the second one. The fixing heater 26 is turned off. In this transition to the switch state, for example, the power supply control circuit 21 detects that the power plug of the multifunction device 1 has been removed from the outlet, and sends a signal indicating this state to the state determination unit 152. The switch control unit 153 switches the relay switch 24 and the like as described above based on the state of the multi-function device 1 determined by the state determination unit 152 based on the signal.

  When the power plug of the multifunction device 1 is attached to the outlet and a signal indicating the state is sent from the power control circuit 21 to the state determination unit 152, the state determination unit 152 determines that the multifunction device 1 is in the plug-in state. The switch control unit 153 causes the heater ON / OFF control circuit 18 to turn off the first fixing heater 17, causes the second fixing heater drive circuit 27 to turn off the second fixing heater 26, and further switches the relay switch 24. While switching to the side which charges the lithium ion battery 23, the battery charge control circuit 25 is turned on, and the lithium ion battery 23 is charged with the power of the external power source 2 (S1). Thereby, the charging of the lithium ion battery 23 is started by the electric power from the external power source 2.

  When the power control circuit 21 detects that the main switch 22 (main power switch) of the multifunction device 1 is turned on (YES in S2), the power control circuit 21 indicates that the main switch 22 is turned on. Is sent to the state determination unit 152. When the state determination unit 152 determines that the state of the multifunction device 1 is the initial startup state and sends a signal indicating the device state to the switch control unit 153, the state control unit 152 The relay switch 24 is switched to the side that discharges the lithium ion battery 23 (the side that charges the electric double layer capacitor 19), the battery charging control circuit 25 is turned off, and the first fixing heater 17 is further turned on by the heater ON / OFF control circuit 18. Is turned on, and the second fixing heater drive circuit 27 turns on the second fixing heater 26 (S3). When the switching control is performed in this way, the first fixing 17 is driven in addition to the second fixing heater 26 if the electric double layer capacitor 19 is charged. This state continues until it is detected by the fixing roller temperature control unit 151 and the switch control unit 153 that the temperature of the fixing roller obtained from the fixing roller temperature sensor 14 has reached the first temperature range described above ( NO in S4).

  When the temperature of the fixing roller reaches the first temperature range by the fixing roller temperature sensor 14 (YES in S4), the state determination unit 152 determines whether a signal indicating that a print instruction has been received from the instruction receiving unit 12 has been input. Judgment is made (S5). When a signal indicating that a print instruction has been received is input from the instruction reception unit 12 (YES in S5), the state determination unit 152 determines that the state of the multifunction device 1 is the print state, and indicates this apparatus state. A signal is sent to the switch control unit 153. The switch control unit 153 switches the relay switch 24 to the side that discharges the lithium ion battery 23 (the side that charges the electric double layer capacitor 19), turns off the battery charging control circuit 25, and causes the second fixing heater drive circuit 27 to While the fixing heater 26 is kept on, the heater ON / OFF control circuit 18 determines that the temperature of the fixing roller is based on the temperature information sent from the fixing roller temperature sensor 14. The first fixing heater 17 is switched on / off in a timely manner so as to maintain the range (S6). During printing, depending on the state of paper passing through the fixing roller, the heating of the fixing roller may be taken away by the recording paper only by heating by the second fixing heater 26, so that the temperature of the fixing roller is reduced. This is to keep the temperature of the fixing roller constant.

  When printing is completed (YES in S7), the state determination unit 152 determines that the state of the multifunction device 1 is in the ready state, and sends a signal indicating the device state to the switch control unit 153. The switch control unit 153 switches the relay switch 24 to the side that discharges the lithium ion battery 23 (the side that charges the electric double layer capacitor 19), turns off the battery charging control circuit 25, and causes the second fixing heater drive circuit 27 to While the fixing heater 26 is kept on, the heater ON / OFF control circuit 18 turns off the first fixing heater 17 (S8).

  Even when the signal indicating that the print instruction is received from the instruction receiving unit 12 in S5 is not input to the state determining unit 152 (NO in S5), the state determining unit 152 sets the state of the multifunction device 1 to the ready state. When it is determined that the device status has been reached, this device status is sent to the switch control unit 153, and the process of S8 is performed.

  When the state determination unit 152 determines that the state of the multifunction device 1 is the ready state, the state determination unit 152 performs the processing of S8 and measures the time elapsed from the time when the state of the multifunction device 1 is determined as the ready state. Start (S9). If a signal indicating that a print instruction has been received is input from the instruction receiving unit 12 to the state determining unit 152 during the elapsed time measurement by the timer 13 (YES in S10), the state determining unit 152 The switch control unit 153 determines that the state 1 is the print state and causes the process of S6 to be performed again. When the timer 13 measures that a predetermined time (for example, 1 minute) has elapsed (YES in S11) without receiving a print instruction (NO in S10), the state determination unit 152 determines that the multifunction device 1 It is determined that the state is the sleep state, and a signal indicating the device state is sent to the switch control unit 153. The switch control unit 153 sets the relay switch 24 to the side that charges the lithium ion battery 23 with the power from the external power source 2, turns on the battery charge control circuit 25, and starts charging the lithium ion battery 23. Further, the switch control unit 153 causes the heater ON / OFF control circuit 18 to turn off the first fixing heater 17 and causes the second fixing heater drive circuit 27 to turn off the second fixing heater 26 (S12). Thus, by turning off both the first fixing heater 17 and the second fixing heater 26, the printer waits for a further print instruction with reduced power consumption.

  When a signal indicating that a print instruction has been received from the instruction receiving unit 12 is input to the state determining unit 152 in the sleep state (YES in S13), the state determining unit 152 indicates that the state of the multifunction device 1 is It is determined that the apparatus is in a rapid startup state, and a signal indicating this apparatus state is sent to the switch control unit 153. In the case of this rapid startup state, the process returns to S3, and the switch control unit 153 switches the relay switch 24 to the side that discharges the lithium ion battery 23 (the side that charges the electric double layer capacitor 19), and the battery charge control circuit 25, the first fixing heater 17 is turned on by the heater ON / OFF control circuit 18, and the second fixing heater 26 is turned on by the second fixing heater driving circuit 27. Thereafter, the processes from S3 to S14 are repeated.

  Note that if it is detected that the main switch 22 is turned off at any point of the processing of S3 to S14, the processing is returned to S1.

  Next, a second embodiment of the process at the time of fixing heater driving control by the multifunction machine 1 will be described. FIG. 7 is a flowchart showing a second embodiment of the process at the time of fixing heater driving control by the multifunction device 1. In addition, about the process similar to 1st Embodiment shown in FIG.5 and FIG.6, the same code | symbol is attached | subjected and description is abbreviate | omitted. When the power plug of the multifunction device 1 is attached to the outlet and the state determination unit 152 determines this state based on a signal from the power supply control circuit 21, the state determination unit 152 determines the electricity bill based on the current time information from the timer 13. Midnight power hours (for example, the time zone from 23:00 to 7:00 the next morning. Since this midnight power time zone is set by the power company, the time zone corresponding to the power company setting is set in the state discriminating unit 152. (S21), and if it is not the midnight power time zone (NO in S21), the switch control unit 153 causes the heater ON / OFF control circuit 18 to The fixing heater 17 is turned off, the second fixing heater drive circuit 27 is in a state where the second fixing heater 26 is turned off, and the relay switch 24 is charged to the side where the lithium ion battery 23 is charged. Ri replaced, but a battery charge control circuit 25 turns off (S22), charging of the lithium ion battery 23 by the power of the external power supply 2 so as not to become performed. Only when the state determination unit 152 determines that it is the midnight power time zone (YES in S21), the battery charge control circuit 25 is turned on (S1), and the lithium ion battery 23 is charged with the power of the external power source 2. . In this way, since the lithium ion battery 23 is charged only during the late-night power hours when the electricity charge is cheap, the electricity charge required for charging the secondary battery can be kept low.

  Next, a description will be given of a third embodiment regarding processing at the time of fixing heater driving control in the multifunction machine 1. FIG. 8 is a flowchart illustrating a third embodiment of processing during fixing heater driving control in the multifunction machine 1. In addition, about the process similar to 1st and 2nd embodiment shown in FIG. 5 thru | or FIG. 7, the same code | symbol is attached | subjected and description is abbreviate | omitted. When the power plug of the multifunction device 1 is attached to the outlet, and the state determination unit 152 determines this state based on a signal from the power control circuit 21, the state determination unit 152 detects the remaining battery level detected by the remaining battery level detection unit 28. Based on the information, it is determined whether or not the lithium ion battery 23 is fully charged (S31). Here, when the state determination unit 152 determines that the lithium ion battery 23 is fully charged (YES in S31), the battery charge control circuit 25 is turned off (S22) and depends on the power of the external power source 2. The lithium ion battery 23 is not charged.

  If state determination unit 152 determines that lithium ion battery 23 is not fully charged (NO in S31), it is further determined whether or not it is a midnight power time zone based on current time information from timer 13. (S21), if it is the midnight power time zone (YES in S21), the battery charge control circuit 25 is turned on (S1), and the lithium ion battery 23 is charged with the power of the external power source 2. Further, even if it is not the midnight power time zone (NO in S21), if the instruction accepting unit 12 accepts an instruction to charge the lithium ion battery 23 (YES in S32), the state determination The unit 152 causes the switch control unit 153 to turn on the battery charge control circuit 25 (S1) and charge the lithium ion battery 23 with the power of the external power source 2. When the instruction receiving unit 12 does not receive an instruction to charge the lithium ion battery 23 from the user (NO in S32), the state determination unit 152 sends the battery control circuit 25 to the switch control unit 153. Is turned off (S22), and the lithium ion battery 23 is not charged. In this way, whether or not to charge the secondary battery in a time zone other than the midnight power time zone can be changed according to an instruction from the user.

  In addition, this invention is not limited to the thing of the said embodiment, The aspect described below can be employ | adopted further. In the second embodiment shown in FIG. 7, when it is not the midnight power time zone (NO in S21), the lithium ion battery 23 is not charged with the power of the external power source 2 (S22). When the state determination unit 152 determines that the lithium ion battery 23 is not fully charged based on the information on the remaining amount of the lithium ion battery 23 detected by the battery remaining amount detection unit 28 even if it is not in the late-night power time zone The switch control unit 153 may perform control so that the lithium ion battery 23 is charged with the power of the external power source 2.

  In the above-described embodiment, the fixing heater is connected to an external power source, and connected to the electric double layer capacitor is separately provided. However, the fixing heater is common to these two power sources. One fixing heater may be connected.

  Further, in the above embodiment, the DC current flows through the first fixing heater 17 and the AC current flows through the second fixing heater 26. However, in the present invention, the current flowing through each fixing heater is the same. It is not limited to using AC or DC.

  In each of the above embodiments, the electric double layer capacitor 19 is used as an auxiliary power source and the lithium ion battery 23 is used as a secondary battery. However, the electric double layer capacitor 19 or the lithium ion battery 23 is an auxiliary power source or a secondary battery. It is only an example of a battery and you may use another as an auxiliary power supply or a secondary battery.

  Further, the configuration and processing shown in FIGS. 1 to 8 are merely one embodiment of the present invention, and the configuration and processing of the present invention are not limited to these.

1 is a block diagram illustrating an internal configuration of a multifunction peripheral that is an embodiment of an image forming apparatus according to the present invention, and particularly a functional configuration centering on a fixing heater control mechanism that controls on / off of a fixing heater that heats a fixing roller; FIG. This is state transition information indicating each state type of the MFP and an event type that triggers transition from each state to another state. It is a figure which shows the state of a heater ON / OFF control circuit, a relay switch, a battery charge control circuit, and a 2nd fixing heater drive circuit in each state of a multifunction peripheral. It is a circuit diagram which shows the circuit image (outline) of a fixing heater control mechanism. 6 is a flowchart illustrating a first embodiment of processing during fixing heater driving control by the multifunction peripheral. 6 is a flowchart illustrating a first embodiment of processing during fixing heater driving control by the multifunction peripheral. 12 is a flowchart illustrating a second embodiment of processing at the time of fixing heater driving control by the multifunction peripheral. 10 is a flowchart illustrating a third embodiment of processing during fixing heater driving control by the multifunction peripheral.

DESCRIPTION OF SYMBOLS 1 Multifunction machine 2 External power supply 11 Image formation part 12 Instruction reception part 13 Timer 14 Fixing roller temperature sensor 15 Control part 17 Fixing heater 18 Heater ON / OFF control circuit 19 Electric double layer capacitor 20 Switching regulator 21 Power supply control circuit 22 Main switch 23 Lithium ion battery 24 Relay switch 25 Battery charge control circuit 26 Fixing heater 27 Second fixing heater drive circuit 28 Battery remaining amount detection unit 41 Diode 151 Fixing roller temperature control unit 152 State determination unit 153 Switch control unit

Claims (7)

An auxiliary power source consisting of a capacitor;
A secondary battery as a power source for charging the capacitor;
A first fixing heater that heats a fixing unit that fixes toner onto a recording sheet with electric power from the auxiliary power source;
A second fixing heater for heating the fixing unit with electric power from an external power source when a main power switch of the image forming apparatus is in an on state;
Switching means for switching between charging the secondary battery with power from the external power source or discharging the power of the secondary battery to charge the auxiliary power source;
State determining means for determining whether the main power switch is in an on state or an off state;
When the state determining means determines that the main power switch is in the on state, the switching means is switched to the side to discharge the secondary battery, and the main power switch is in the off state by the state determining means. An image forming apparatus comprising: a control unit that switches the switching unit to a side where the secondary battery is charged by the external power source when it is determined to be present. First fixing heater driving means for switching whether to drive the first fixing heater;
A second fixing heater driving means for switching whether to drive the second fixing heater with electric power from the external power source;
The state determination means is in a heater-on state in which the first and second fixing heaters are driven by the first and second fixing heater driving means when the main power switch is in an on-state, or the first And further determining whether or not the first and second fixing heaters are stopped by the second fixing heater driving means.
Wherein, when the main power switch is determined that the on state by said state judgment means, only, to charge the auxiliary power supply to discharge the rechargeable battery when it is determined that the heater ON state 2. The image forming apparatus according to claim 1, wherein when the switching unit is switched to the side and the heater is turned off , the switching unit is switched to a side where the secondary battery is charged by the external power source .   3. The image forming apparatus according to claim 1, wherein the switching unit switches to a side for charging the auxiliary power supply when power is not supplied to the image forming apparatus. A time zone discriminating means for discriminating whether or not it is a midnight power time zone;
Further comprising power supply switching means for switching whether to supply power from the external power source to the secondary battery,
When the state determining unit determines that the main power switch is in an OFF state and the time zone determining unit determines that the current time is a midnight power time zone, the control unit The supply switching means is switched to the side where the power from the external power source is supplied to the secondary battery, the state determining means determines that the switch is off, and the time zone determining means determines that the current time is midnight. 4. The image forming apparatus according to claim 1, wherein, when it is determined that the power is not in a power time zone, the power supply switching unit is switched to a side where power from the external power source is not supplied to the secondary battery. 5. . A charge degree determining means for determining whether or not the secondary battery is fully charged;
Even if the control means determines that the switch-off state is determined by the state determination means, and the time zone determination means determines that the current time is a midnight power time zone, 5. The power supply switching unit is switched to a side where power from the external power source is not supplied to the secondary battery when the determination unit determines that the secondary battery is fully charged. Image forming apparatus.   The control means determines that the state determination means determines that the state of the image forming apparatus is that the main power switch is off, and the charge degree determination means indicates that the secondary battery is not fully charged. Is determined, the power supply switching means supplies power from the external power source to the secondary battery even if the time zone discrimination means determines that the current time is not a midnight power time zone. The image forming apparatus according to claim 5, wherein the image forming apparatus is switched to the side. A setting accepting means for accepting a setting by a user as to whether or not to charge the secondary battery;
The control means determines that the secondary battery is fully charged by the charge degree determination means when the state determination means determines that the state of the image forming apparatus is the main power switch is OFF. In the case where it is determined that there is no power and the setting accepting unit accepts the setting that the charging is performed, this is a case where the time zone discriminating unit determines that the current time is not a midnight power time zone. The image forming apparatus according to claim 5, wherein the power supply switching unit is switched to a side where power from the external power source is supplied to the secondary battery.

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