JP6747422B2 - Power supply device, image forming device - Google Patents

Description

The present invention relates to a power supply device capable of restarting a power supply control circuit and an image forming apparatus including the power supply device.

Generally, a power supply device included in an image forming apparatus includes a power supply control circuit. The power supply control circuit controls the operating states of the plurality of power supply circuits in response to changes in the operating state of the manual switch and control signals output from the processor. The power supply control circuit is realized by, for example, a PMIC (Power Management Integrated Circuit).

For example, it is known that the power supply control circuit sets a startup sequence or a shutdown sequence of the plurality of power supplies according to a digital value held in a register (see, for example, Patent Document 1).

JP, 2013-89060, A

By the way, the power supply control circuit may be in a frozen state for some reason. Generally, the power supply control circuit is often recovered from the frozen state by restarting.

An object of the present invention is to provide a power supply device capable of restarting a power supply control circuit in a frozen state and an image forming apparatus including the power supply device with a simple configuration.

A power supply device according to one aspect of the present invention includes a primary power supply circuit, a plurality of secondary power supply circuits, a power supply control circuit, and a switch relay circuit. The primary power supply circuit outputs the first DC power when the input output control signal is active, shuts off the output of the first DC power when the output control signal is negative, and further always outputs the first DC power. 2 Output DC power. The plurality of secondary power supply circuits are supplied with the first DC power and supply power to the plurality of loads. The power supply control circuit is supplied with the first DC power and controls the operating states of the plurality of secondary power supply circuits according to changes in the operating state of the manual switch. The switch relay circuit outputs the output control signal, which is active when the second DC power is supplied and the manual switch is not operated, to the primary power supply circuit, and when the manual switch is operated, The negative output control signal is output to the primary power supply circuit when it continues for a predetermined long press time or longer.

An image forming apparatus according to another aspect of the present invention includes the power supply device, the manual switch, and a print processing device. The print processing apparatus forms an image on a sheet.

According to the present invention, it is possible to provide a power supply device capable of restarting a power supply control circuit in a frozen state and an image forming apparatus including the power supply device with a simple configuration.

FIG. 1 is a configuration diagram of an image forming apparatus including a power supply device according to the embodiment. FIG. 2 is a block diagram of the power supply device according to the embodiment. FIG. 3 is a diagram illustrating a switch input circuit included in the power supply device according to the embodiment. FIG. 4 is a diagram illustrating a switch relay circuit included in the power supply device according to the embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. The following embodiments are examples of embodying the present invention and do not limit the technical scope of the present invention.

[Configuration of Image Forming Apparatus 10]
The power supply device 5 according to the embodiment is a part of the image forming apparatus 10. The image forming apparatus 10 shown in FIG. 1 includes a print processing apparatus 4 that executes print processing by an electrophotographic method.

The printing process is a process of forming an image on the sheet 9. The sheet 9 is a sheet-shaped image forming medium such as paper or resin film.

As shown in FIG. 1, the image forming apparatus 10 includes a sheet conveying mechanism 3, a print processing device 4, a power supply device 5, an operating device 8a, a display device 8b, a power switch 8c, and the like, which are arranged in the main body 100.

The operation device 8a and the display device 8b are user interface devices. The operation device 8a is a device that receives a user operation, and includes, for example, an operation button or a touch panel device. The display device 8b is a device that displays information, and includes, for example, a liquid crystal panel unit.

The power switch 8c is a manual switch that switches from one of an ON state and an OFF state to the other according to a user's operation. The power switch 8c is an automatic return contact.

In the present embodiment, the power switch 8c is in the OFF state when it is not operated, and is in the ON state when it is operated. When the operation of the power switch 8c is released, the power switch 8c returns from the ON state to the OFF state.

In the sheet transport mechanism 3, the sheet delivery mechanism 30 delivers the sheet 9 stored in the sheet storage unit 101 to the sheet transport path 300, and the plurality of pairs of transport rollers 31 move the sheet 9 along the sheet transport path 300. Transport.

The print processing device 4 is a print processing device including an optical scanning unit 40, a photoconductor 41, a charging device 42, a developing device 43, a toner replenishing unit 44, a transfer device 45, a cleaning device 46, a fixing device 47, a motor 400, and the like. ..

The drum-shaped photoconductor 41 rotates, and the charging device 42 charges the surface of the photoconductor 41. The optical scanning unit 40 scans the charged light beam on the surface of the photoconductor 41 to write an electrostatic latent image on the surface of the photoconductor 41.

The developing device 43 supplies the toner 90 to the surface of the photoconductor 41 to develop the electrostatic latent image into a toner image. The transfer device 45 transfers the toner image on the surface of the photoconductor 41 to the moving sheet 9 on the sheet conveying path 300.

The fixing device 47 fixes the toner image on the sheet 9 by heating the toner image transferred to the sheet 9.

The cleaning device 46 removes the toner 90 remaining on the surface of the photoconductor 41. The toner supply unit 44 supplies unused toner 90 to the developing device 43.

The motor 400 drives the rotating body and the photoconductor 41 included in the sheet conveying mechanism 3, the developing device 43, the transfer device 45, the fixing device 47, and the like.

The power supply device 5 is a DC power supply device that converts an AC input voltage Va0 supplied from the external power supply 1000 into a DC output voltage VD2. The output voltage VD2 is supplied to a plurality of loads. The external power source 1000 is, for example, a commercial power source.

[Outline of power supply device 5]
As shown in FIG. 2, the power supply device 5 includes a primary power supply circuit 51, a plurality of secondary power supply circuits 52, a PMIC 53, and a switch input circuit 54. Further, the power supply device 5 includes a CPU (Central Processing Unit) 55, a RAM (Random Access Memory) 56, and a secondary storage device 57.

In the example shown in FIG. 2, the primary power supply circuit 51 is mounted on the power supply board 5a. On the other hand, the plurality of secondary power supply circuits 52, PMIC 53, switch input circuit 54, CPU 55, RAM 56 and secondary storage device 57 are mounted on a control board 5b different from the power supply board 5a.

The primary power supply circuit 51 is a circuit that outputs DC power. For example, it is conceivable that the primary power supply circuit 51 includes a switching power supply circuit that converts the input voltage Va0 into DC intermediate voltages VD11 and VD12.

In the present embodiment, the primary power supply circuit 51 outputs the DC first intermediate voltage VD11 to the first power supply line L1 and outputs the DC second intermediate voltage VD12 to the second power supply line L2. The difference between the first intermediate voltage VD11 and the second intermediate voltage VD12 will be described later.

The first intermediate voltage VD11 is applied to the plurality of secondary power supply circuits 52 and the PMIC 53. The power supplied to the plurality of secondary power supply circuits 52 and the PMIC 53 by the first intermediate voltage VD11 is an example of the first DC power.

When the first intermediate voltage VD11 is supplied to the plurality of secondary power supply circuits 52, the plurality of secondary power supply circuits 52 each output a DC output voltage VD2. The plurality of secondary power supply circuits 52 are connected to the plurality of third power supply lines L3 that are independently connected.

The plurality of third power supply lines L3 are connected to different loads. The plurality of secondary power supply circuits 52 output the output voltage VD2 to the plurality of third power supply lines L3. As a result, the plurality of secondary power supply circuits 52 supply power to the plurality of loads.

The PMIC 53 operates by being supplied with the first intermediate voltage VD11. The PMIC 53 controls the operating states of the plurality of secondary power supply circuits 52 according to changes in the operating state of the power switch 8c. The PMIC 53 is an example of a power supply control circuit.

In the present embodiment, the PMIC 53 inputs the manual switch signal Sg1 indicating the operating state of the power switch 8c through the switch input circuit 54.

The power switch 8c is connected to the ground line and the switch signal line L0. The switch signal line L0 is connected to the power supply line of the second intermediate voltage VD12 via the resistance element R0. The resistance element R0 is a so-called pull-up resistance.

The switch input circuit 54 is connected to the power switch 8c through the switch signal line L0. When the power switch 8c is turned on, the switch signal line L0 and the ground line are short-circuited.

In the example shown in FIG. 3, the switch input circuit 54 is a known switch circuit including a resistance element R1 and a transistor TR0. The switch input circuit 54 outputs an active manual switch signal Sg1 when the power switch 8c is operated, and outputs a negative manual switch signal Sg1 when the power switch 8c is not operated.

In the present embodiment, the PMIC 53 controls the states of the plurality of secondary power supply circuits 52 into three operating states, that is, an activated state, a standby state and a stopped state.

The start-up state is a state in which the most secondary power supply circuit 52 is operating among the three operating states. When the plurality of secondary power supply circuits 52 are in the activated state, the CPU 55 is operating in the normal mode, and the image forming apparatus 10 can execute all jobs related to image formation.

The standby state is a state in which the number of operating secondary power supply circuits 52 is smaller than that in the starting state, and is a state in which power consumption is lower than that in the starting state. When the plurality of secondary power supply circuits 52 are in the standby state, the CPU 55 is operating in the power saving mode which consumes less power than the normal mode.

The stopped state is a state in which the number of operating secondary power supply circuits 52 is smaller than that in the standby state, and the power consumption is lower than that in the standby state. The CPU 55 is stopped when the plurality of secondary power supply circuits 52 are in the stopped state.

Therefore, when the plurality of secondary power supply circuits 52 are in the stopped state, the PMIC 53 shifts the operating state of the plurality of secondary power supply circuits 52 to another state only when the operating state of the power switch 8c changes. ..

The CPU 55 is one of the loads. That is, the CPU 55 is supplied with the output voltage VD2 from one of the plurality of secondary power supply circuits 52 through one of the plurality of third power supply lines L3. The operation device 8a and the display device 8b are also a part of the plurality of loads.

The CPU 55 executes various data processing by executing a program stored in the secondary storage device 57 in advance, and further controls a plurality of devices including the PMIC 53.

For example, the CPU 55 controls a motor (not shown) included in the print processing device 4. That is, the print processing device 4 is controlled by the CPU 55. Further, the CPU 55 outputs the power supply control signal Sg0 to the PMIC 53.

Further, when the plurality of secondary power supply circuits 52 shift from the stopped state or the standby state to the activated state, the CPU 55 executes the activation notification process.

The CPU 55 is activated by itself when the plurality of secondary power supply circuits 52 shift from the stopped state or the standby state to the activated state. Therefore, it is conceivable that the CPU 55 executes the activation notification processing when activated by the start of energization from the secondary power supply circuit 52.

For example, it is conceivable that the startup notification process includes one or both of an initial screen startup process and a power lamp lighting process. The initial screen activation process is a process of switching the display device 8b from a non-display state to a state in which a predetermined initial screen is displayed. The power lamp lighting process is a process of switching the power lamp included in the display device 8b from the extinguished state to the lit state.

Each of the initial screen activation process and the power lamp lighting process is an example of a process of notifying the transition to the activation state. Further, the stopped state and the standby state are examples of predetermined non-activated states. The CPU 55 and the display device 8b that execute the activation notification process are examples of the activation notification device.

It should be noted that other processor such as DSP (Digital Signal Processor) may be adopted instead of the CPU 55.

The RAM 56 is a volatile storage device that temporarily stores a program executed by the CPU 55 or data accessed by the CPU 55. The RAM 56 is a so-called main storage device.

The secondary storage device 57 is a computer-readable non-volatile storage device. For example, the secondary storage device 57 may be a flash memory or a ROM (Read Only Memory). The secondary storage device 57 stores a program executed by the CPU 55 in advance.

When the plurality of secondary power supply circuits 52 are in the standby state, it is possible that a communication device (not shown) receives a print job from another device. In this case, the CPU 55 itself shifts from the power saving mode to the normal mode and outputs the power supply control signal Sg0 instructing the shift to the activated state. This causes the plurality of secondary power supply circuits 52 to transition from the standby state to the activated state.

Further, in the case where the plurality of secondary power supply circuits 52 are in the stop state or the standby state, when the operation state of the power supply switch 8c changes, the PMIC 53 causes the operation state of the plurality of secondary power supply circuits 52 to be in the start state. Shift to.

The change of the manual switch signal Sg1 from negative to active indicates that the operating state of the power switch 8c has changed.

As described above, the PMIC 53 controls the operating states of the plurality of secondary power supply circuits 52 according to the change in the operating state of the power switch 8c and the content of the power control signal Sg0.

By the way, the PMIC 53 may be in a frozen state for some reason. Generally, the PMIC 53 is often recovered from the frozen state by restarting.

The power supply device 5 has a configuration capable of restarting the frozen PMIC 53 with a simple configuration. The configuration will be described below.

[Details of power supply device 5]
As shown in FIG. 2, the power supply device 5 further includes a switch relay circuit 6. The switch relay circuit 6 is connected to the power switch 8c and the primary power circuit 51. That is, the switch relay circuit 6 is connected to the power supply switch 8c through the switch signal line L0 together with the switch input circuit 54.

The switch relay circuit 6 operates when the second intermediate voltage VD12 is applied. The power supplied to the switch relay circuit 6 by the second intermediate voltage VD12 is an example of the second DC power. It should be noted that one of the switch input circuit 54 and the switch relay circuit 6 may include a resistance element R0 that pulls up the switch signal line L0.

The switch relay circuit 6 outputs an active output control signal Sg3 to the primary power supply circuit 51 when the power switch 8c is not operated. Further, the switch relay circuit 6 outputs a negative output control signal Sg3 to the primary power supply circuit 51 when the state where the power switch 8c is operated continues for a predetermined long press time or longer.

The primary power supply circuit 51 outputs the first intermediate voltage VD11 when the input output control signal Sg3 is active. On the other hand, the primary power supply circuit 51 blocks the output of the first intermediate voltage VD11 when the input output control signal Sg3 is negative.

Further, the primary power supply circuit 51 constantly outputs the second intermediate voltage VD12. Of course, it is premised that power is being supplied to the primary power supply circuit 51.

Specifically, the primary power supply circuit 51 includes an output switch circuit 51a. The output switch circuit 51a makes the output line of the first intermediate voltage VD11 conductive when the output control signal Sg3 is active, and cuts off the output line of the first intermediate voltage VD11 when the output control signal Sg3 is negative. ..

[Switch relay circuit 6]
For example, as shown in FIG. 4, the switch relay circuit 6 includes a capacitor C0 and a comparator CM0.

The capacitor C0 is electrically connected to the power supply line of the second intermediate voltage VD12 and the switch signal line L0 connected to the power switch 8c.

In the example shown in FIG. 4, the capacitor C0 is connected to the switch signal line L0 via the diode D0 and the resistance element R2 which are connected in parallel.

The comparator CM0 compares the terminal voltage VC0 of the capacitor C0 with the reference voltage VD120 and outputs the comparison result as an output control signal Sg3. The reference voltage VD120 is generated based on the second intermediate voltage VD12. In the example shown in FIG. 2, the voltage dividing circuit including the two resistance elements R3 and R4 generates the reference voltage VD120 based on the second intermediate voltage VD12.

The capacitor C0 is charged with the second DC power when the power switch 8c is not operated. Further, the capacitor C0 is discharged to the ground line through the power switch 8c when the power switch 8c is operated.

The resistance element R2 between the switch signal line L0 and the capacitor C0 suppresses the discharging speed of the capacitor C0 when the power switch 8c is operated.

The comparator CM0 outputs the active output control signal Sg3 when the terminal voltage VC0 of the capacitor C0 is higher than the reference voltage VD120. Further, the comparator CM0 outputs a negative output control signal Sg3 when the terminal voltage VC0 of the capacitor C0 is lower than the reference voltage VD120.

Further, the resistance element R5 is provided in the feedback line of the comparator CM0. The resistance element R5 imparts hysteresis to the operation of the comparator CM0.

The output line of the output control signal Sg3 is connected to the supply line of the second intermediate voltage VD12 through the resistance element R6. The resistance element R6 is a so-called pull-up resistance.

When the power switch 8c is not operated, the capacitor C0 is charged and the terminal voltage VC0 of the capacitor C0 exceeds the reference voltage VD120. After that, unless the power switch 8c is operated, the state in which the terminal voltage VC0 exceeds the reference voltage VD120 is maintained.

Therefore, the switch relay circuit 6 outputs the active output control signal Sg3 to the primary power supply circuit 51 when the power switch 8c is not operated.

On the other hand, when the power switch 8c is operated, the capacitor C0 is discharged through the power switch 8c. The terminal voltage VC0 of the capacitor C0 becomes lower than the reference voltage VD120 when a predetermined long press time elapses after the discharge of the capacitor C0 starts. After that, as long as the power switch 8c is operated, the terminal voltage VC0 is maintained below the reference voltage VD120.

Therefore, the switch relay circuit 6 outputs the negative output control signal Sg3 to the primary power supply circuit 51 when the state where the power switch 8c is operated continues for the long press time or longer.

The long press time is determined by the time constant of the RC circuit including the second resistance element R2 and the capacitor C0.

When the power switch 8c is not operated again after the negative output control signal Sg3 is output, the terminal voltage VC0 of the capacitor C0 gradually increases and eventually exceeds the reference voltage VD120. As a result, the switch relay circuit 6 outputs the active output control signal Sg3 again to the primary power supply circuit 51.

Therefore, when the power switch 8c is not operated after the state where the power switch 8c is operated continues for the long press time or more, the primary power supply circuit 51 causes the first intermediate voltage VD11 to the PMIC 53 and the secondary power supply circuit 52. The output of is temporarily cut off. As a result, the PMIC 53 is restarted.

In the present embodiment, the long press time is longer than the time from the start of the operation of the power switch 8c to the execution of the activation notification process by the CPU 55.

Normally, when the user operates the power switch 8c to activate the image forming apparatus 10, at least when the initial screen is displayed on the display device 8b or when the power lamp is turned on, the power switch 8c is turned on. Stop the operation of.

Therefore, when the PMIC 53 is operating normally, the user stops operating the power switch 8c before the long press time elapses after the user starts operating the power switch 8c. As a result, the output of the first intermediate voltage VD11 is continued and the PMIC 53 is not restarted.

On the other hand, when the PMIC 53 is in the freeze state, even if the power switch 8c is operated by the user, the plurality of secondary power supply circuits 52 do not shift to the startup state, and the initial screen is displayed and the power lamp is turned on. Does not happen. In this case, the user can easily continue to operate the power switch 8c until the long press time elapses.

Then, when the state where the power switch 8c is operated continues for the long-pressing time or more, the PMIC 53 is restarted by the action of the switch relay circuit 6. As a result, when the PMIC 53 returns to the normal state, the PMIC 53 shifts the plurality of secondary power supply circuits 52 from the stopped state or the standby state to the activated state. As a result, the image forming apparatus 10 starts up normally.

According to the present embodiment, it is possible to realize the power supply device 5 capable of restarting the frozen PMIC 53 with a simple configuration.

3: Sheet conveying mechanism 4: Print processing device 5: Power supply device 5a: Power supply board 5b: Control board 6: Switch relay circuit 8a: Operation device 8b: Display device 8c: Power switch (manual switch)
9: Sheet 10: Image forming device 30: Sheet sending mechanism 31: Conveying roller pair 40: Optical scanning unit 41: Photoconductor 42: Charging device 43: Developing device 44: Toner replenishing unit 45: Transfer device 46: Cleaning device 47: Fixing device 51: Primary power supply circuit 51a: Output switch circuit 52: Secondary power supply circuit 54: Switch input circuit 55: CPU (processor)
56: RAM
57: secondary storage device 90: toner 100: main body 101: sheet accommodating section 300: sheet conveying path 400: motor 1000: external power supply C0: capacitor CM0: comparator D0: diode L0: switch signal line L1: first power supply line L2: Second power supply line L3: Third power supply line R0 to R6: Resistor element Sg0: Power supply control signal Sg1: Manual switch signal Sg3: Output control signal VC0: Terminal voltage VD11: First intermediate voltage (first DC power)
VD12: second intermediate voltage (second DC power)
VD120: Reference voltage VD2: Output voltage Va0: Input voltage

Claims (5)

When the input output control signal is active, the first DC power is output, when the output control signal is negative, the output of the first DC power is shut off, and the second DC power is always output. A primary power supply circuit,
A plurality of secondary power supply circuits that are supplied with the first DC power and supply power to a plurality of loads;
A power supply control circuit that is supplied with the first DC power and that controls the operating states of the plurality of secondary power supply circuits according to changes in the operating state of the manual switch;
The second DC power is supplied, the output control signal that is active when the manual switch is not operated is output to the primary power supply circuit, and the state where the manual switch is operated is a predetermined long press. And a switch relay circuit that outputs the negative output control signal to the primary power supply circuit when it continues for a time or more. One of the plurality of loads is a processor that outputs a power supply control signal to the power supply control circuit,
The power supply device according to claim 1, wherein the power supply control circuit controls operation states of the plurality of secondary power supply circuits according to a change in an operation state of the manual switch and a content of the power supply control signal. The switch relay circuit is
A capacitor electrically connected to the power supply line of the second DC power and the manual switch;
A comparator that compares the terminal voltage of the capacitor with a reference voltage based on the second DC power and outputs the comparison result as the output control signal;
The capacitor is charged by the second DC power when the manual switch is not operated, and discharged through the manual switch when the manual switch is operated,
The comparator outputs the active output control signal when the terminal voltage of the capacitor is higher than the reference voltage, and outputs the negative output control signal when the terminal voltage of the capacitor is lower than the reference voltage. The power supply device according to claim 1, which outputs the power supply. A power supply device according to any one of claims 1 to 3,
The manual switch,
An image forming apparatus comprising: a print processing apparatus that forms an image on a sheet. The plurality of secondary power supply circuits further comprises a start notification device that notifies the transition to the start state when the predetermined non-start state shifts to a start state in which power consumption is larger than the non-start state. ,
The image forming apparatus according to claim 4, wherein the long press time is longer than a time from when the operation of the manual switch is started to when the activation notification device notifies.