JP5760553B2 - Power supply device, electronic device, and image forming apparatus - Google Patents

Description

  The present invention relates to a power supply device and an electronic apparatus including an image forming apparatus such as a digital copying machine, a digital multifunction peripheral, and a facsimile machine including the power supply device, and more particularly to an energy saving (hereinafter referred to as “energy saving”) technology.

  In recent years, copiers, printers, facsimiles using an electrophotographic process, and multi-function machines combining these functions have become multifunctional, and the structure has become complicated accordingly, and the maximum power consumption tends to increase. Yes. In the electrophotographic process, the toner image transferred onto the paper by the transfer process is fixed by the fixing process. The waiting time until the fixing device rises for fixing, and the printing (image forming) operation or copying operation. In order to reduce the factors of the image forming apparatus itself and the waiting time of the operator, such as the temporary interruption of the operation due to a decrease in the fixing temperature, the power supplied to the fixing heater tends to increase.

On the other hand, since there is a limit to the power that can be supplied from a normal power supply line, this is a major limitation in designing the device.
Therefore, in order not to exceed the maximum suppliable power of the power supply line, a system using a capacitor (power storage device) has been proposed as seen in Patent Document 1, for example. Further, in Patent Document 2, in order not to damage each part during the image forming operation, when power supply is interrupted by a power failure or the like, control is performed so that power is supplied from the auxiliary power supply device to the image forming part. Thus, there is disclosed a configuration in which even if there is a job in the middle of image formation, the image formation operation of the job is continued.

However, in a system using a capacitor whose voltage decreases as the stored power decreases, such as Patent Document 1, when a certain amount of power is supplied to the system, the current increases and the circuit load increases. Therefore, in order to suppress this, the use at a predetermined voltage or less is avoided. For this reason, when the stored power is used in combination with other functions such as a power failure response, it is necessary to add a capacitor capacity sufficient to satisfy the added function operation, resulting in a significant increase in cost.
Further, even the device described in Patent Document 2 requires the addition of the capacity of the auxiliary power supply device due to the addition of functions, which also increases the cost.

  The present invention has been made in view of the above points, and can efficiently realize a plurality of functions within a range that does not exceed the maximum suppliable power of the power supply line by using low-cost power storage means (capacitor or the like). The purpose is to do so.

In order to achieve the above object, the present invention provides the following power supply device, electronic device, and image forming apparatus.
A power supply device according to the present invention is a power supply device that supplies power, the power storage means for storing power, and the power storage means serving as a power source, each based on an operable power storage voltage range with different set lower limit values. A plurality of auxiliary power supply means for generating and supplying power of different predetermined voltages from the stored energy of the storage voltage of the power storage means , the plurality of auxiliary power supply means being a first auxiliary power supply means and a second auxiliary power supply constructed by the means.

Further, the lower limit of the first operable storage voltage range (for example, the operable storage voltage range of the auxiliary heating element in the fixing device that realizes the function for shortening the start-up time) set for the first auxiliary power supply means. to less than the value, the lower limit value of the second operating electrical storage voltage range (e.g., operating electrical storage voltage range of the arithmetic and control means for implementing a power failure corresponding function) is set for the second auxiliary power unit.
Then, the current the lower limit of the first operating electrical storage voltage range by current flowing through the first auxiliary power unit, the lower limit of the second operating electrical storage voltage range flowing through the second auxiliary power unit It is set respectively by.

Electronic device according to the invention, the above power supply device, a first load means driven by power supply from said first auxiliary power unit in the power supply, the power supply from the second auxiliary power unit And a second load means for driving.
In addition, a first load means that is driven by power supply from the first auxiliary power supply means in the power supply device and a second load means that is driven by power supply from the second auxiliary power supply means are provided. The operation of the second load means for realizing a power failure response function capable of responding to a power failure is between the lower limit value of the first operable power storage voltage range and the lower limit value of the second operable power storage voltage range. It may be an electronic device in which the storage voltage that can be set is set for the second auxiliary power supply means.

Alternatively, a first load means that is driven by power supply from the first auxiliary power supply means in the power supply device and a second load means that is driven by power supply from the second auxiliary power supply means are provided. The storage voltage that enables the operation of the second load means for realizing the power failure response function capable of responding to a power failure within the first operable power storage voltage range is set for the second auxiliary power supply means. It may be an electronic device.
In these electronic devices, the second load means includes a power failure detection means for detecting a power failure, and the second load means for realizing the power failure response function when a power failure is detected by the power failure detection means. And an arithmetic control means for performing a shutdown process which is the above-described operation.

In the electronic apparatus, it is desirable that the arithmetic control unit restricts its control when the storage voltage of the storage unit is less than the storage voltage at which the shutdown process is possible.
In the electronic device, the upper limit value of the first operable storage voltage range is such that the storage voltage at which the first load means capable of operating the start time shortening function capable of responding to shortening of the start time can be operated is the first voltage. It may be set for one auxiliary power supply means.
The electronic apparatus is an image forming apparatus, and the first load means includes an auxiliary heating element in the fixing device for fixing the toner image transferred onto the sheet. The auxiliary power supply unit may supply power to the auxiliary heating element during the startup operation of the image forming apparatus.

  The image forming apparatus includes a charging unit that charges the power storage unit, and the calculation control unit has a storage voltage of the power storage unit that is less than a storage voltage at which the shutdown process can be performed during the start-up operation. Alternatively, the shutdown process can be performed when a power failure is not detected by the power failure detection means after the power failure detection means is detected in the normal operation mode or standby mode after the start-up operation is completed. When the charging means is charged until reaching the stored storage voltage, and when shifting from the standby mode to the off mode, the charging means is charged until reaching the upper limit value of the first operable storage voltage range. Can be done.

According to this invention, the plurality of auxiliary power supply means of the power supply device uses the power storage means as a power source, and the storage energy of the power storage voltage of the power storage means is determined based on the operable power storage voltage range in which the set lower limit values are different. By generating and supplying power with different predetermined voltages, electronic devices equipped with this power supply device can use load means that can operate at low voltages (such as arithmetic control means that realize power failure response functions) and their operating voltages. A plurality of load means that can be operated at different voltages, such as load means that can be operated at a high voltage (such as an auxiliary heating element in a fixing device that realizes a function for shortening the start-up time), It is possible to operate efficiently within a range not exceeding the maximum suppliable power of the power supply line using a capacitor. That is, it is possible to efficiently realize a plurality of functions within a range that does not exceed the maximum suppliable power of the power supply line using low-cost power storage means. In addition, the utilization rate of the power storage means can be increased.
According to the electronic apparatus and the image forming apparatus provided with the power supply device described above, a plurality of functions can be efficiently realized at low cost.

1 is a block diagram illustrating a configuration example of a main part of an image forming apparatus, which is an embodiment of an electronic apparatus equipped with a power supply device according to the present invention, and a power supply destination from the power supply device. FIG. 2 is a timing chart showing a first example of a relationship between voltage transition of capacitor 44 and an operation mode in FIG. 1. FIG. 6 is a timing chart showing a second example of the relationship between the voltage transition of capacitor 44 and the operation mode in the same manner. FIG. 2 is a flowchart illustrating an example of a charging process in the image forming apparatus illustrated in FIG. 1.

Hereinafter, embodiments for carrying out the present invention will be specifically described with reference to the drawings.
In the following embodiments, the first load means (auxiliary heating element in the fixing device) that realizes the function for shortening the start-up time is fed from the power storage means such as a capacitor (supplied with power) to reduce the start-up time of the system. The system shown has the following characteristics.
That is, the lower limit value of the operable storage voltage of the first auxiliary power supply means (capacitor converter) for supplying power to the first load means and the second load means for supplying power to the second load means (CPU or the like) for realizing the power failure response function. And the lower limit value of the operable power storage voltage of the auxiliary power supply means (capacitor converter) is individually set, and the lower limit value of the operable power storage voltage of the second auxiliary power supply means is set as the operable power storage voltage of the first auxiliary power supply means. A characteristic is that the voltage is set lower than the lower limit value.

First, the configuration and basic operation of the main part of an image forming apparatus, which is an embodiment of an electronic apparatus equipped with a power supply device according to the present invention, will be described.
FIG. 1 is a block diagram illustrating a configuration example of a main part and a power supply destination (load) from a power supply device.
In this image forming apparatus (hereinafter also simply referred to as “apparatus”), AC power supplied from an AC (alternating current) line 41 via a main power switch (hereinafter referred to as “SW”) 40 is used as a main power supply 42. It is converted into DC (direct current) power by an included AC / DC converter 42a, and a part is directly supplied as power for each of the + 5V and + 24V loads 47a and 47c. The AC power is also input to the capacitor charger 43 as charging means, and can be used for charging the capacitor 44.

The capacitor 44 as a power storage means (auxiliary power source) is constituted by a large capacity capacitor such as an electric double layer capacitor. In addition to the electric double layer capacitor, various selections can be made. In this embodiment, an electric double layer capacitor that can be charged and discharged in a short time and has a long life is used.
As the capacitor 44 discharges as a characteristic of the electric double layer capacitor, the terminal voltage becomes lower. Therefore, the capacitor converters 45a and 45b are arranged after the capacitor 44 so that the output voltage becomes constant.

  Capacitor converters 45a and 45b use any one of a boost converter, a step-down converter, and a step-up / down converter according to the specifications of the charging voltage (storage voltage) of capacitor 44 and the lower limit voltage for use. Each of the capacitor converters 45a and 45b uses the capacitor 44 as a power source, and has a predetermined voltage different from the stored energy of the stored voltage of the capacitor 44 based on the operable stored voltage range having different set lower limit values. Functions as first and second auxiliary power supply means for generating and supplying power (electric power) are performed together with the control unit 20 and switching circuits 46a and 46b described later.

The switching circuit 46a uses a + 24V power supply (drive power supply) generated by the AC / DC converter 42a based on the AC power supplied from the AC line 41, and a capacitor converter 45a from the energy stored (accumulated) in the capacitor 44. The + 24V power source produced through the switch is switched according to the control by the control unit 20 and supplied to the + 24V system load 47d corresponding to the first load means.
The switching circuit 46b is generated through the capacitor converter 45b from the + 5V power (control unit power) generated by the AC / DC converter 42a based on the AC power supplied from the AC line 41 and the energy stored in the capacitor 44. The + 5V power source is switched according to the control by the control unit 20 and supplied to the + 5V system load 47b corresponding to the second load means.

  Here, the + 24V system load 47d is a fixing unit for fixing a toner image transferred onto a sheet such as a sheet as a load unit that realizes a function for reducing the startup time that can cope with a reduction in the startup time. An auxiliary heater described later in the device (hereinafter referred to as “fixing device”) 48 is included. The + 5V system load 47b includes a control unit 20 including a CPU (Central Processing Unit) that is a calculation control unit as a load unit that realizes a power failure response function capable of handling a power failure. + 5V system load 47b also includes main power supply 42, capacitor charger 43, capacitor converters 45a and 45b, switching circuits 46a and 46b, and voltage detection circuits 49 and 50.

  The control unit 20 uses a microcomputer including a CPU, a ROM, and a RAM, and the CPU controls the entire apparatus (for example, a digital copying machine) by developing and executing a program in the ROM on the RAM. The loads 47a to 47d can be operated sequentially according to each operation mode. Although this control unit 20 is a part of the + 5V system load 47b, it can be supplied with + 5V power from a battery (not shown) and is always operable.

  The control unit 20 also controls charging / discharging of the capacitor 44. The storage of the capacitor 44 detected by the voltage detection circuit 49 during the start-up operation of the device and during a period up to a predetermined time after the start-up operation. When the voltage is equal to or higher than the predetermined voltage, the switching circuit 46a is switched and operated so that + 24V power generated by the capacitor converter 45a is supplied from the energy stored in the capacitor 44 (charged energy) to the + 24V system load 47d. At this time, the margin generated with respect to the power supplied from the AC line 41 controls the fixing heater driving circuit 42b, or a fixing roller incorporating a main heater as a main heating element and an auxiliary heater as an auxiliary heating element, or The amount of electric power supplied to the fixing device 48 including a fixing belt that is stretched and rotated by a plurality of rollers including a heating roller including these heaters is increased.

  Further, when the voltage detection circuit 50 corresponding to the power failure detection means detects the power failure state (actually the voltage at the time of the power failure), the control unit 20 detects that the stored voltage of the capacitor 44 detected by the voltage detection circuit 49 is equal to or higher than a predetermined voltage. If so, the switching circuit 46b is switched so that the + 5V power generated by the capacitor converter 45b is supplied to the + 5V system load 47b from the energy stored in the capacitor 44, and the control operation is continued.

Here, as will be described later with reference to FIG. 2, the predetermined voltage is set to a different voltage value during the start-up operation of the apparatus and during a power failure.
In this embodiment, the power supply destination of the capacitor 44 at the time of starting the apparatus is the + 24V system load 47c, and the amount of power supplied to the fixing device 48 is increased by a margin generated with respect to the power supplied from the AC line 41. However, the present invention can be applied to a system configuration in which the power of the capacitor 44 is directly supplied to the fixing device 48.

Next, the relationship between the voltage transition of the capacitor 44 in FIG. 1 and the state (operation mode) of the device will be described.
FIG. 2 is a timing chart showing a first example of the relationship between the voltage transition of the capacitor 44 of FIG. 1 and the operation mode.
This timing chart is a graph of the storage transition of the capacitor 44 in accordance with the operation mode, with the horizontal axis indicating time and the vertical axis indicating the storage voltage of the capacitor 44.
The control unit 20 in FIG. 1 enters a return mode when an operation instruction is issued by an operator's operation on an operation unit (not shown) (timing A), and starts a startup operation (return operation) of the apparatus.

  At this time, the power stored in the capacitor 44 is used to shorten the startup time of the fixing device 48. As a result, the voltage of the capacitor 44 falls to the lower limit of the operable storage voltage range of the auxiliary heater (hereinafter also simply referred to as “starting time shortening support function”) in the fixing device that realizes the start time shortening support function. This voltage drop period is shown as a discharge period T1. At this time (timing B), the amount of power supplied from the capacitor 44 is as large as several hundred watts. When a certain amount of power is supplied to the system within the auxiliary power supply period, the terminal voltage decreases as the capacitor 44 discharges. Therefore, the output current of the capacitor 44 increases with time. In the constituent circuits such as the capacitor converters 45a and 45b, since the conduction current is limited, the lower limit value is set so as not to be used below a predetermined voltage. That is, the capacity of the capacitor 44 is set so as to ensure an auxiliary power capacity that can satisfy the target start-up time in the operable storage voltage range.

  After the off mode, the capacitor is charged so that the fully charged state (the charged voltage Va of the capacitor 44 is set in advance) at the timing F at which auxiliary power is required to shorten the startup time. A charging operation for causing the battery 43 to charge is performed. The operation period is shown as a charging period T4. The “off mode” is an operation mode in which power supply from the main power source 42 to each load is turned off by an automatic off function after a predetermined time has passed in the standby mode.

  Here, there is a difference between the off-mode transition timing C and the timing F at which auxiliary power is required to shorten the start-up time. The fixing device 48 stores the auxiliary power for a while after the transition to the off-mode due to heat storage by the auxiliary heater. This is because it is possible to start up at a target startup time without need. Further, the capacitor 44 has a self-discharge action, and the power consumption becomes smaller when the stored voltage is low. Therefore, if the power is stored only when necessary, the energy saving effect can be enhanced.

Next, an operation example at the time of a power failure in the image forming apparatus shown in FIG. 1 will be described.
In this example, when a power failure is detected by the voltage detection circuit 50 (timing D) during the normal operation mode or the standby mode in which the printing (image formation) operation of the image forming apparatus after the return operation is completed, the control unit 20 Shutdown processing such as processing for the next start-up and various data protection processing is executed. At this time, as described above, since the control unit 20 operates using the stored power of the capacitor 44, the stored voltage of the capacitor 44 is lower than the lower limit of the operable storage voltage range of the function for shortening the startup time. The control unit 20 (hereinafter, also simply referred to as “power failure response function”) that realizes the power failure response function set to “1” is lowered to near the lower limit of the operable storage voltage range. This voltage drop period is shown as a discharge period T2. In this example, the period between D and E is the power failure period T0.

Here, the power consumed in the shutdown process is as small as several tens of watts or less, and even if the stored power of the capacitor 44 is used at a voltage lower than the lower limit of the operable storage voltage range of the function for shortening the startup time, the circuit is loaded. Therefore, the operable power storage voltage range of the power failure response function is set separately from the operable power storage voltage range of the startup time shortening support function.
When the power failure state is no longer detected by the voltage detection circuit 50, that is, when the power failure is eliminated (recovered from the power failure), a charging operation is performed in preparation for the next power failure. The operation period is shown as a charging period T3.

  As described in the charging operation in the charging period T4, since it is possible to start up with a target startup time without requiring auxiliary power for a while after the transition to the off mode, the shutdown process is performed in the charging operation in the charging period T3. The second charging voltage that is lower than the lower limit value of the operable storage voltage range of the function for shortening the start-up time (but higher than the lower limit value of the operable storage voltage range of the function for power failure) so that only the electric power necessary for charging is stored (Set voltage) The battery is charged until it reaches Vb.

Next, how to determine the second charging voltage Vb (calculation example) will be described in detail.
For example, if the power required for the shutdown process is 10 W (control voltage 5 V × consumption current 2 A) and the limit value of the conduction current of the discharge circuit of the capacitor 44 (that is, the current flowing to the capacitor converter 45 b) is 5 A, it is used in the shutdown process. The lower limit value of the stored voltage of the capacitor 44 is determined to be 2 V. If the capacity of the capacitor 44 is 75 F (eight capacitors of 600 F are connected in series), the remaining energy at this time is 150 J.

If the time required for the shutdown process is 120 seconds, the amount of power consumed in the shutdown process is 5V × 2A × 120s = 1200J, and 1350J energy is added to the energy (150J) described above. The resulting capacitor voltage is 6V. This is calculated from an equation of 1/2 × C (capacitor capacity) × V (capacitor voltage) ² = W (storage energy). Only when the capacitor 44 maintains a voltage equal to or higher than the capacitor voltage (6V), the shutdown process can be normally performed, and this voltage is preset as the second charging voltage Vb.

  In this example, the second charging voltage Vb is set without considering the power consumed in the shutdown process, the variation in processing time, the variation in detection of the storage voltage, the voltage drop due to the self-discharge action of the capacitor 44, and the like. If these are set in consideration, a more stable power failure response function can be obtained.

As described above, the operation when the second charging voltage Vb is set lower than the lower limit voltage (lower limit value) of the operable storage voltage range of the activation time reduction function has been described with reference to the drawings. The operation when the second charging voltage Vb is set higher than the lower limit voltage of the operable storage voltage range will be described with reference to FIG. Except for the operation in the normal shutdown process disabled period G, the operation is the same as the operation in FIG.
FIG. 3 is a timing chart showing a second example of the relationship between the voltage transition of the capacitor 44 of FIG. 1 and the operation mode.

In this example, as in FIG. 2, when the return operation is started from the timing A, the storage voltage of the capacitor 44 drops to the lower limit of the operable storage voltage range of the function for shortening the startup time. At this time (timing B), since the voltage is lower than the second charging voltage Vb, the charging operation is continued. The operation period is indicated as a charging period T5.
If a power failure occurs in a section where the voltage is lower than the second charging voltage Vb, naturally, normal shutdown processing is impossible. In this section, the main control by the control unit 20 is limited. For example, access to a storage device such as an HDD (hard disk) (not shown) is stopped, and control is performed so that data destruction does not occur even when a power failure occurs.

In this example, the control configuration restricts the main control by the control unit 20 in the above section so that the shutdown process can be normally performed in preparation for the next startup operation in order to prevent data destruction. It is possible to adopt a control configuration in which priority is given to the shutdown processing itself upon power failure such as preventing (division).
As described above, two different operations when a power failure occurs during the printing operation or the standby mode after completion of the return operation have been described with reference to FIGS. 2 and 3. However, when a power failure occurs during the return mode and the off mode, The basic operation is the same except that the accumulated voltage of the capacitor 44 is high when the power failure control is started (timing D). The power failure response control will be described in detail with reference to FIG.

Next, a charging process in the image forming apparatus shown in FIG. 1 will be described.
FIG. 4 is a flowchart showing an example of the charging process.
The control unit 20 in FIG. 1 performs a constant charging process in preparation for a return operation and a power failure that do not know when it is required. Specifically, it is as shown below.
First, in step S1, it is determined whether or not the printing operation is being performed.

Here, in a system that uses the capacity of the AC line (AC commercial power supply) to the maximum during the return operation or the printing operation, the charging operation causes the capacity of the AC line to be exceeded, so the charging operation is not performed. . Since the image forming apparatus of this embodiment uses the capacity of the AC line 41 to the maximum, if it is determined in step S1 that the printing operation is being performed (including the returning operation), the process does not proceed to step S2 and the subsequent steps. The charging operation for charging the charger 43 cannot be performed.
Further, as described above, the fixing device 48 can start up for a while without the need for auxiliary power for a while after shifting to the off mode due to heat storage. Therefore, the auxiliary device necessary for shortening the recovery time is required. Electric power may be charged when necessary.

Therefore, in step S2, the control unit 20 determines whether or not auxiliary power (recovery auxiliary power source) is necessary to shorten the recovery time. If necessary, the control unit 20 proceeds to step S3, and if not necessary, proceeds to step S5. Transition.
Here, the necessary timing of the auxiliary power necessary for shortening the recovery time is determined based on the temperature of the fixing device 48 or the time after the transition to the off mode considering the temperature lowering transition of the fixing device 48. The temperature of the fixing device 48, for example, the surface temperature of a fixing roller having a built-in fixing heater, can be detected by a temperature sensor (not shown) arranged to face the fixing roller.

If it is determined in step S2 that auxiliary power is required to shorten the recovery time, the process proceeds to step S3, where the storage voltage of the capacitor 44, which is an auxiliary power supply, is confirmed, and the storage voltage is preset. Only when the charging voltage is lower than the first charging voltage Va, the charging operation is started in step S4. Thereby, the capacitor charger 43 performs charging (full charge) until the stored voltage of the capacitor 44 reaches the first charging voltage Va.
Here, the first charging voltage Va is used to assist the fixing device 48 in order to shorten the startup time predicted in advance from the lower limit value (operable storage voltage lower limit value) of the operable storage voltage range of the start time reduction function. The voltage is set to a value equal to or greater than the amount of power required for the heater.

On the other hand, if it is determined in step S2 that auxiliary power is not necessary to shorten the recovery time, the process proceeds to step S5, where the storage voltage of the capacitor 44, which is an auxiliary power supply, is confirmed, and the storage voltage is preset. Only when the charging voltage is lower than the second charging voltage Vb, the charging operation is started in step S6. Thereby, the capacitor charger 43 performs charging until the stored voltage of the capacitor 44 reaches the second charging voltage Vb.
Here, in the example of FIG. 2, the second charging voltage Vb is obtained by adding the electric energy necessary for performing the shutdown processing predicted in advance to the lower limit value of the operable storage voltage range of the function for reducing the startup time. The voltage is set higher than the specified voltage.

The threshold voltage (threshold) in step 5 and the charging voltage in step 6 are set to the same voltage as the second charging voltage Vb, but the charging voltage is set higher than the threshold voltage in consideration of self-discharge. In addition, the charging operation is not repeated in a short time, the control can be simplified, and the wasteful power consumption of the charging control itself can be reduced. The same applies to the setting of the threshold voltage in step 3 and the charging voltage in step 4.
Then, since the stored power amount of the capacitor 44 decreases with time due to the self-discharge action, the process returns to step 1 even after the completion of the charging operation, and the repeated charging process (storage voltage monitoring process) is performed.

As described above, in the image forming apparatus according to this embodiment, the control unit 20 and the capacitor converters 45a and 45b constituting the first and second auxiliary power supply means of the power supply apparatus use the capacitor 44 as the power storage means as the power source. Based on the operable storage voltage ranges with different set lower limits, power sources of different predetermined voltages + 24V and + 5V are generated from the storage energy of the storage voltage of the capacitor 44, and the + 24V system load 47d (first load) Means), a + 5V system load 47b (control unit 20 or the like that realizes a power failure response function) capable of operating at a low voltage by supplying it to the + 5V system load 47b (second load means) or a voltage higher than the operating voltage Such as a + 24V system load 47d that can be operated with (such as an auxiliary heater in the fixing device 48 that realizes a function for shortening the start-up time). A plurality of load means operable in pressure, using small capacitor 44 of capacitance, can be effectively operated without exceeding the maximum available power of the AC line 41 is a power supply line.
That is, a plurality of functions can be efficiently realized within a range not exceeding the maximum suppliable power of the AC line 41 using the low-cost capacitor 44. Moreover, the utilization factor of the capacitor 44 can be increased.

  Note that the three or more auxiliary power supply means of the power supply device use the power storage means such as a capacitor as a power source, and the storage energy of the storage voltage of the power storage means based on the operable storage voltage range in which the set lower limit values are different. It is also possible to generate and supply power of different predetermined voltages from each other.

As described above, the embodiment in which the present invention is applied to the power supply apparatus and the image forming apparatus including the power supply apparatus has been described. However, the present invention is not limited to this and can be applied to other electronic devices including the power supply apparatus.
In addition, this invention is not limited to embodiment mentioned above, It cannot be overemphasized that all the technical matters contained in the technical idea described in the claim are object.

  As is apparent from the above description, according to the present invention, the power supply device uses a low-cost power storage means and efficiently realizes a plurality of functions within a range not exceeding the maximum suppliable power of the power supply line. Can do. Therefore, it is possible to provide a power supply device and an electronic device that can efficiently realize a plurality of functions at low cost.

20: Control unit 41: AC line 42: Main power supply 42a: AC / DC converter 42b: Fixing heater drive circuit 43: Capacitor charger 44: Capacitor 45a, 45b: Capacitor converter 46a, 46b: Switching circuit 47a, 47b: + 5V system Load 47c, 47d: + 24V system load 48: Fixing device 49, 50: Voltage detection circuit

JP 2007-236159 A JP 2005-1458581 A

Claims (9)

A power supply for supplying power,
Power storage means for storing power;
A plurality of power supplies having different predetermined voltages are generated and supplied from the stored energy of the storage voltage of the storage means based on the operable storage voltage ranges in which the set lower limit values are different from each other. Auxiliary power means ,
The plurality of auxiliary power supply means comprises a first auxiliary power supply means and a second auxiliary power supply means,
The lower limit value of the second operable power storage voltage range for the second auxiliary power supply means is less than the lower limit value of the first operable power storage voltage range set for the first auxiliary power supply means. Set,
The lower limit value of the first operable storage voltage range is a current flowing through the first auxiliary power supply means, and the lower limit value of the second operable storage voltage range is a current flowing through the second auxiliary power supply means. Each of the power supplies is set by the above . 2. The power supply device according to claim 1 , driven by power supply from the first auxiliary power supply means in the power supply device, and driven by power supply from the second auxiliary power supply means. An electronic device comprising: a second load means. 2. The power supply device according to claim 1 , driven by power supply from the first auxiliary power supply means in the power supply device, and driven by power supply from the second auxiliary power supply means. Second load means,
Operation of the second load means for realizing a power failure response function capable of responding to a power failure is possible between a lower limit value of the first operable storage voltage range and a lower limit value of the second operable storage voltage range. The electronic device is characterized in that a storage voltage is set for the second auxiliary power supply means. 2. The power supply device according to claim 1 , driven by power supply from the first auxiliary power supply means in the power supply device, and driven by power supply from the second auxiliary power supply means. Second load means,
Within the first operable power storage voltage range, a power storage voltage that enables operation of the second load means for realizing a power failure response function capable of responding to a power failure is set for the second auxiliary power supply means. An electronic device characterized by The second load means includes a power failure detection means for detecting a power failure, and a shutdown process that is an operation of the second load means for realizing the power failure response function when a power failure is detected by the power failure detection means. The electronic apparatus according to claim 3 , further comprising an arithmetic control unit that performs the operation. The electronic apparatus according to claim 5 , wherein the arithmetic control unit restricts its control when a storage voltage of the storage unit is less than a storage voltage at which the shutdown process is possible. The electronic device according to claim 6 ,
The upper limit value of the first operable storage voltage range is such that the storage voltage that enables the operation of the first load means that realizes the start time reduction function capable of responding to reduction of the start time is the first auxiliary power supply means. An electronic device characterized by being set for. The electronic device according to claim 7 is an image forming apparatus,
The first load means includes an auxiliary heating element in the fixing device for fixing the toner image transferred onto the sheet,
The image forming apparatus according to claim 1, wherein the first auxiliary power supply supplies power to the auxiliary heating element during the start-up operation of the image forming apparatus. The image forming apparatus according to claim 8 .
Charging means for charging the power storage means,
The arithmetic control unit is configured to operate in a normal operation mode or a standby mode when the storage voltage of the storage unit becomes less than the storage voltage at which the shutdown process can be performed during the startup operation, or after the startup operation is completed. After a power failure is detected by the power failure detection means at the time of mode, when the power failure is no longer detected by the power failure detection means, the charging means is charged until reaching the stored voltage that enables the shutdown process, An image forming apparatus characterized in that, when the standby mode is shifted to the off mode, the charging unit is charged until the upper limit value of the first operable storage voltage range is reached.

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