JP6330781B2 - Power supply life determination apparatus and image forming apparatus having the same - Google Patents

Description

  The present invention relates to a device for determining the life of a power supply device including a photocoupler. The present invention also relates to an image forming apparatus including this apparatus.

  Image forming apparatuses such as multifunction peripherals, printers, copiers, and facsimile machines are provided with a power supply device that generates a DC voltage from an AC voltage supplied from a commercial power supply. As this power supply device, a switching power supply including a transformer may be used. An example of such a switching power supply is described in Patent Document 1.

Specifically, Patent Document 1 includes an inductance component and a switching element, and the voltage generated in the first winding of the inductance component is fed back to the control terminal of the switching element as a drive signal to turn on / off the switching element. When a voltage signal corresponding to the input voltage to the self-excited switching power supply is obtained from the second winding of the inductance component, and when it is detected from the voltage signal that the input voltage has decreased below a predetermined value, the switching element is A self-excited switching power supply circuit provided with an output cut-off circuit for turning off is described. From the viewpoint of malfunction or damage of the load device, the power supply is stopped when the input voltage is lowered to a predetermined value (Patent Document 1: Claim 1, paragraph [0011]).

Japanese Patent Laid-Open No. 11-098839

  In an image forming apparatus such as a multifunction machine, a printer, a copier, and a facsimile machine, a switching power source that includes a transformer and obtains a DC voltage from an AC power source may be mounted on a power supply board. Further, a plurality of photocouplers are mounted on a power supply board, and signals (information) may be exchanged between the primary side and the secondary side while insulating the primary side and the secondary side of the transformer.

  The photocoupler includes a light emitting element such as an LED and a light receiving element that receives an optical signal from the light emitting element. Deterioration progresses while using the light emitting element. As the deterioration progresses, the amount of light emitted from the light-emitting element when a current of the same magnitude flows is reduced. In addition, in order to keep the current flowing in the light receiving element at the same time during light reception, the input current to the light emitting element may have to be gradually increased. The light emitting element emits light based on the output voltage on the secondary side. Unless the output voltage on the secondary side is increased more than necessary, it is necessary to replace a light emitting element that does not emit light with a desired light amount.

  On the other hand, various elements such as transformers and photocouplers are mounted on the power supply board, and many resources are used. In order to protect the environment and save resources, it is conceivable to reuse the power supply board. In addition, it is possible to contribute to environmental protection and resource saving if the deteriorated parts in the power supply board are replaced to greatly extend the life of the power supply board and delay the disposal time of the power supply board.

  However, in the photocoupler, the light emitting element and the light receiving element are stored in one package (in the cover). Therefore, the degree of deterioration is difficult to understand. Therefore, there is no problem with all the photocouplers on the substrate, and it cannot be determined at a glance whether the power substrate can be reused as it is or which photocoupler needs to be replaced to reuse or extend the life of the power substrate. As described above, there is a problem that it is difficult to determine the lifetime of each photocoupler, which hinders the reuse and extension of the life of the power supply board.

  The power supply circuit described in Patent Document 1 is a self-excited switching power supply circuit including a transformer and a photocoupler. However, only one photocoupler is used. Further, the lifetime of the photocoupler cannot be determined and the above problem cannot be solved.

  The present invention has been made in view of the above-described problems of the prior art, and informs the information on the lifetime of each photocoupler based on the actual lighting state of the light emitting element, and the necessity of reusing the power supply board or replacing parts To help judge.

  In order to achieve the above object, an invention according to claim 1 includes a notification unit, a power supply board, a time measuring unit, a storage unit, an operation panel, and a control unit. The notification unit notifies a life determination result. The power supply board converts an input alternating current into a direct current and outputs the direct current. The power supply substrate includes a controller that adjusts an output voltage by controlling a switching time or frequency of the switching element. The power supply board includes a plurality of photocouplers each including a light emitting element and a light receiving element, the light receiving element being connected to the controller. The time measuring unit measures the lighting time of each of the light emitting elements. The said memory | storage part memorize | stores the total lighting time of each said light emitting element based on the timing result of the said time measuring part. The operation panel accepts an execution instruction for determining the lifetime of the photocoupler. When the execution instruction is made, the control unit determines a lighting possible time of each of the light emitting elements, subtracts the corresponding cumulative lighting time from the lighting possible time, until the lifetime of each of the photocouplers is exhausted Estimated remaining time is obtained, and each of the estimated remaining times is notified to the notification unit as the life determination result.

  According to the present invention, it is possible to provide a power supply life determination apparatus and an image forming apparatus that notify information related to the life of a photocoupler based on an actual lighting state of a light emitting element. Further, it is possible to provide a power supply life determination device and an image forming apparatus that can easily determine the necessity of reuse of a power supply board and replacement of parts.

1 is a diagram illustrating an example of a printer according to an embodiment. It is a figure which shows an example of the electric power supply system of the printer which concerns on embodiment. It is a figure which shows an example of the power supply board which concerns on embodiment. It is a flowchart which shows an example of the flow of time-measurement of the lighting time of each light emitting element which concerns on embodiment. It is a figure for demonstrating the time measurement regarding each light emitting element of the power supply board which concerns on embodiment. It is a figure which shows an example of the total time data which concern on embodiment. It is a flowchart which shows an example of the flow of a lifetime judgment of each photocoupler which concerns on embodiment. It is a figure which shows an example of the data for time setting concerning embodiment.

  Hereinafter, an image forming apparatus including the power supply life determination apparatus 1 according to the present invention will be described with reference to FIGS. The printer 100 will be described as an example of the image forming apparatus. However, each element such as configuration and arrangement described in this embodiment does not limit the scope of the invention and is merely an illustrative example.

(Outline of image forming apparatus)
First, the printer 100 according to the embodiment will be described with reference to FIG. FIG. 1 is a diagram illustrating an example of a printer 100 according to the embodiment.

  The printer 100 includes a control unit 2 (control board) and a storage unit 3. The control unit 2 controls the overall operation of the apparatus and controls each unit of the printer 100. The control unit 2 includes a CPU 21 that performs processing such as computation, an image processing unit 22 that performs image processing necessary for printing on image data, and a time measuring unit 23 that measures time. The storage unit 3 is a storage device such as a ROM, a RAM, and an HDD, and stores a control program and data.

  The control unit 2 is connected to the operation panel 4 so as to be communicable. The operation panel 4 includes a display panel 41 that displays information such as a setting screen, the status of the printer 100, and a message. The operation panel 4 also includes an input receiving unit 42 that receives user operations such as a touch panel and hard keys provided on the operation panel 4. Then, the control unit 2 recognizes the settings and operations made by the input receiving unit 42. The control unit 2 controls the printer 100 so as to operate as set by the user.

  The printer 100 includes a printing unit 5. The printing unit 5 includes an engine control unit 50, a paper feeding unit 5a, a conveyance unit 5b, an image forming unit 5c, and a fixing unit 5e. The engine control unit 50 and the control unit 2 are communicably connected. The control unit 2 gives a print instruction, the contents of the print job, and image data used for printing to the engine control unit 50. Upon receiving an instruction from the control unit 2, the engine control unit 50 controls the operations of the paper feeding unit 5a, the conveyance unit 5b, the image forming unit 5c, and the fixing unit 5e, and performs paper feeding, paper conveyance, toner image formation, transfer, Actually controls printing-related processing such as fixing.

  The engine control unit 50 supplies sheets one by one to the sheet feeding unit 5a. The engine control unit 50 transports the supplied paper to the transport unit 5b through the image forming unit 5c and the fixing unit 5e to a discharge tray (not shown). The engine control unit 50 causes the image forming unit 5c to form a toner image to be placed on the paper conveyed from the conveyance unit 5b, and transfers the toner image onto the paper. The engine control unit 50 fixes the toner image transferred on the paper to the fixing unit 5e. The conveyance unit 5b discharges the sheet on which the toner image is fixed to the discharge tray.

  In addition, the printer 100 includes a communication unit 24. The communication unit 24 is an interface for communicating with the computer 200. The communication unit 24 communicates with the computer 200 via a network or a cable. The control unit 2 is connected to the communication unit 24. The communication unit 24 receives printing data including data indicating printing contents such as image data and data indicating settings relating to printing from the computer 200. The control unit 2 causes the printing unit 5 to perform printing based on the printing data.

(Power supply system)
Next, an example of the power supply system in the printer 100 according to the embodiment will be described with reference to FIG. FIG. 2 is a diagram illustrating an example of a power supply system of the printer 100 according to the embodiment.

  The printer 100 includes a power supply board 6 (primary power supply unit) and a secondary power supply unit 6a. The power supply board 6 is connected to a commercial power supply Vac (AC power supply) by a power cable (not shown). The power supply board 6 includes a switching power supply that generates direct current from alternating current. Details of the power supply substrate 6 will be described later. The power supply board 6 outputs a DC voltage when the commercial power supply Vac is connected. The power supply board 6 generates, for example, DC 24V for driving the motor.

  The secondary power supply unit 6a includes a plurality of power conversion circuits such as a regulator and a DCDC converter. The secondary power supply unit 6 a generates a plurality of types of DC voltages based on the generated voltage of the power supply substrate 6. In each device, a range of voltage values to be input (supplied) is determined. The secondary power supply unit 6a generates a plurality of types of voltages within the range of voltage values to be input (supplied), and includes a control board (CPU 21, image processing unit 22, storage unit 3, timing unit 23, communication unit 24), engine It supplies to each board | substrate like a board | substrate (engine control part 50), a panel board | substrate (the display panel 41, the input reception part 42), and each device distribute | arranged to each board | substrate.

  Here, in order to prevent an abnormal operation from occurring, the order of voltage application (power supply) and voltage cutoff (power supply stop) to each device is predetermined. In addition, when a plurality of types of voltages are applied to one device, the order of voltages to be applied may be determined. Therefore, a power supply sequence circuit 6b is provided in the printer 100. The power supply sequence circuit 6b starts voltage application to each substrate and each device in the printer 100 in a predetermined order. Further, the power supply sequence circuit 6b stops voltage application to each substrate and each device in the printer 100 in a predetermined order. For this reason, the power sequence circuit 6b controls ON / OFF of the power conversion circuit included in the secondary power supply unit 6a.

(Power supply board 6)
Next, the power supply board 6 according to the embodiment will be described with reference to FIG. FIG. 3 is a diagram illustrating an example of the power supply substrate 6 according to the embodiment.

  The power supply board 6 includes an insulating transformer L1. On the primary side of the isolation transformer L1, there are input terminals A and B, a rectifier 61, a capacitor C1, a switching element Q1, a controller 62, a first phototransistor 91 (a part of the first photocoupler 71), and a second phototransistor. 92 (a part of the second photocoupler 72) and a third phototransistor 93 (a part of the third photocoupler 73) are provided.

  On the secondary side of the insulation transformer L1, output terminals C and D, a diode D5, a smoothing capacitor C2, a smoothing coil L2, a first light emitting element 81 (a part of the first photocoupler 71), a resistor R1, and a constant voltage diode ZD , A resistor R2, a second light emitting element 82 (a part of the second photocoupler 72), a third light emitting element 83 (a part of the third photocoupler 73), a resistor R3, a transistor Tr1, and a resistor R4. As the first light emitting element 81, the second light emitting element 82, and the third light emitting element 83, LEDs can be used.

  First, the primary side will be described. A commercial power supply Vac (AC power supply) is connected to the input terminals A and B. The alternating current input to the power supply substrate 6 is full-wave rectified to direct current by the rectifying unit 61. The rectifying unit 61 is a diode bridge including input terminals E and F and output terminals G and H, a diode D1, a diode D2, a diode D3, and a diode D4. As shown in FIG. 3, the input terminal A is connected to the input terminal E. The input terminal E is connected to the anode of the diode D1 and the cathode of the diode D4. The input terminal B is connected to the input terminal F. The input terminal F is connected to the anode of the diode D2 and the cathode of the diode D3. The output terminal G is connected to the cathode of the diode D1 and the cathode of the diode D2. The output terminal H is connected to the anode of the diode D3 and the anode of the diode D4.

  The capacitor C1 has one end connected to the output terminal G and the other end connected to the output terminal H. The capacitor C1 smoothes the voltage rectified by the rectifying unit 61 as the primary DC voltage V1. The primary DC voltage V1 is input to one end of the primary coil L11 of the insulation transformer L1. The switching element Q1 is connected to the other end of the primary coil L11. In the example shown in FIG. 3, a MOSFET is shown as the switching element Q1.

  The drain of the switching element Q1 is connected to the other end of the primary coil L11, and the source of the switching element Q1 is connected to the output terminal H. The gate of the switching element Q1 is connected to the controller 62. The controller 62 is a control IC that controls ON / OFF (switching frequency and duty ratio) of the switching element Q1. The controller 62 inputs the PWM signal to the gate of the switching element Q1, turns on / off the current of the primary coil L11, and generates a pulse corresponding to the frequency of the PWM signal in the primary coil L11.

  The controller 62 is connected to the collector of each phototransistor (first phototransistor 91, second phototransistor 92, third phototransistor 93) of each photocoupler. The emitter of each phototransistor is connected to the output terminal H. Each phototransistor draws current from the controller 62 when in the ON state.

  Next, the secondary side will be described. In the power supply substrate 6, the anode of the diode D5 is connected to one end of the insulating transformer L1. The diode D5 makes the direction of current constant. One end of the smoothing capacitor C2 and one end of the smoothing coil L2 are connected to the cathode of the diode D5. The other end of the smoothing capacitor C2 is connected to the output terminal D (ground). The other end of the smoothing coil L2 is connected to the output terminal C. The smoothing coil L2 and the smoothing capacitor C2 remove and smooth the voltage ripple induced in the secondary coil L12. As a result, the smoothed secondary DC voltage V2 is output from the output terminal C.

  A series circuit of the first light-emitting element 81 of the first photocoupler 71 and the resistor R1 is connected between the secondary DC voltage V2 and the ground (output terminal C and output terminal D). Further, a series circuit of the constant voltage diode ZD, the second light emitting element 82 of the second photocoupler 72, and the resistor R2 is connected between the secondary DC voltage V2 and the ground (output terminal C and output terminal D). A series circuit of the third light emitting element 83 of the third photocoupler 73, the resistor R3, and the transistor Tr1 is connected between the secondary DC voltage V2 and the ground (output terminal C and output terminal D).

  Next, control of the secondary DC voltage V2 using the feedback signal of the first photocoupler 71 will be described. When the secondary DC voltage V2 rises and a current flows through the first light emitting element 81 of the first photocoupler 71, the first light emitting element 81 emits light. Light (feedback signal) from the first light emitting element 81 reaches the first phototransistor 91 in the package of the first photocoupler 71. As a result, the first phototransistor 91 is turned on, and a current flows through the first phototransistor 91.

  The controller 62 recognizes the magnitude of the current flowing through the first phototransistor 91 (the magnitude of the current drawn by the first phototransistor 91 from the controller 62). Then, the controller 62 supplies a PWM signal corresponding to the magnitude of the current of the first phototransistor 91 to the switching element Q1. The current of the first phototransistor 91 increases as the light amount of the first light emitting element 81 increases, and decreases as the light amount decreases. For example, when the secondary DC voltage V2 is smaller than a reference current value predetermined as the current of the first phototransistor 91 when the secondary DC voltage V2 is a set value (for example, DC 24V), the secondary DC voltage is increased by increasing the ON duty. The PWM signal is changed in the direction in which V2 increases.

  Thus, when the power supply substrate 6 is operating, the current of the first light emitting element 81 → the current of the first phototransistor 91 → the PWM signal adjustment → the switching of the switching element Q1 → the pulse at the primary coil L11 → by induction. Generation of voltage in the secondary coil L12 → smoothing, ripple removal → generation of the secondary DC voltage V2 is repeated while reflecting feedback using the first photocoupler 71.

  Next, overvoltage detection of the secondary DC voltage V2 using the second photocoupler 72 will be described. The upper limit value of the secondary DC voltage V2 is determined by the constant voltage diode ZD. When the secondary DC voltage V2 rises abnormally and exceeds the upper limit value, a current flows through the second light emitting element 82 of the second photocoupler 72, and the second light emitting element 82 emits light. Light (overvoltage detection signal) from the second light emitting element 82 reaches the second phototransistor 92 within the package of the second photocoupler 72. As a result, the second phototransistor 92 is turned on, and a current flows through the second phototransistor 92.

  The controller 62 recognizes that a current has flowed through the second phototransistor 92. That is, the controller 62 recognizes that the magnitude of the secondary DC voltage V2 exceeds the upper limit value based on the overvoltage detection signal. At this time, the controller 62 stops ON / OFF of the switching element Q1 (sets the ON duty of the PWM signal to zero). As a result, the operation of the power supply board 6 (generation of the secondary DC voltage V2) is stopped, and damage to each circuit and load in the power supply board 6 is prevented.

  Next, mode switching using the third photocoupler 73 will be described. First, the mode of the printer 100 will be described. The printer 100 has a normal mode in which power is supplied to all of the printer 100 and the printer 100 is kept in a usable state. The printer 100 also has a power saving mode in which power supply to a predetermined supply stop portion is stopped and power consumption is reduced as compared with the normal mode.

  Specifically, during the power saving mode, the power supply sequence circuit 6b stops the power conversion circuit that supplies power to the supply stop portion of the secondary power supply unit 6a. In the printer 100, the operation stop unit 4 and the printing unit 5 are included in the supply stop portion.

  The control unit 2 (CPU 21) recognizes that the condition for shifting to the power saving mode predetermined in the normal mode is satisfied. At this time, the control unit 2 shifts the printer 100 to the power saving mode. Specifically, the control unit 2 gives an instruction to shift to the power saving mode to the power supply sequence circuit 6b. The power supply sequence circuit 6b stops the power conversion circuit that supplies power to the supply stop portion based on the instruction).

  Transition conditions are determined as appropriate. The control unit 2 (CPU 21) sets a predetermined time such as several minutes without entering the next print job in the communication unit 24 after the normal mode or the print job is completed. When the time has elapsed, it is determined that the transition condition is satisfied. Further, the control unit 2 determines that the transition condition is satisfied when an instruction to shift to the power saving mode is input to the operation panel 4. The transition condition is not limited to the above.

  During the power saving mode, the control unit 2 (CPU 21) recognizes that a predetermined return condition is satisfied. At this time, the control unit 2 returns the printer 100 to the normal mode. Specifically, the control unit 2 gives an instruction to return to the normal mode to the power supply sequence circuit 6b. The power sequence circuit 6b operates a power conversion circuit that supplies power to the supply stop portion based on the instruction.

  Return conditions are also determined as appropriate. The control unit 2 (CPU 21) determines that the return condition is satisfied when a print job (printing data) is input to the communication unit 24 during the power saving mode. Further, the control unit 2 determines that the return condition is satisfied when the operation panel 4 is operated. Note that, even in the power saving mode, power is supplied to a portion that accepts an operation of the communication unit 24 or the electric operation panel 4. The return condition is not limited to the above.

  Transmission of a mode switching signal using the third photocoupler 73 (transition to the power saving mode or return to the normal mode) is transmitted to the controller 62. Specifically, the CPU 21 of the control unit 2 inputs a signal to the base of the transistor Tr1. For example, with the shift to the power saving mode, the CPU 21 inputs High to the base of the transistor Tr1. When the transistor Tr1 is turned on, a current flows through the third light emitting element 83 of the third photocoupler 73, and the third light emitting element 83 emits light. Light from the third light emitting element 83 (mode switching signal indicating that the power saving mode should be set) reaches the third phototransistor 93 in the package of the third photocoupler 73. As a result, the third phototransistor 93 is turned on, and a current flows through the third phototransistor 93.

  The controller 62 recognizes that a current has flowed through the third phototransistor 93. That is, the controller 62 recognizes that it should shift to the power saving mode. In the power saving mode, the power consumption of the printer 100 is reduced. Therefore, with the shift to the power saving mode, the controller 62 lowers the frequency of the PWM signal from that in the normal mode. Thereby, switching loss can be reduced.

  On the other hand, with the return to the normal mode, the CPU 21 inputs Low to the base of the transistor Tr1. When the transistor Tr1 is turned off, no current flows through the third light emitting element 83 of the third photocoupler 73 and the third light emitting element 83 is turned off (mode switching signal indicating that the normal mode should be set). As a result, the third phototransistor 93 changes to the OFF state.

  The controller 62 recognizes that the third phototransistor 93 is turned off. That is, the controller 62 recognizes that it should return to the normal mode. In normal mode, it is necessary to react to a sudden load current. Therefore, with the return to the normal mode, the controller 62 makes the frequency of the PWM signal higher than that in the power saving mode.

(Time measurement of each light emitting element)
Next, timing of the lighting time of each light emitting element included in the power supply substrate 6 according to the embodiment will be described with reference to FIGS. FIG. 4 is a flowchart illustrating an example of a flow of measuring the lighting time of each light emitting element. FIG. 5 is a diagram for explaining the timing of each light emitting element included in the power supply substrate 6. FIG. 6 is a diagram illustrating an example of the accumulated time data 33 according to the embodiment.

  The start of FIG. 4 is a time when the power supply substrate 6 starts to generate the secondary DC voltage V2 by being connected to the commercial power supply Vac. The flowchart of FIG. 4 is continued until the operation of the power supply board 6 is stopped, for example, when the power cable is disconnected from the outlet.

  As shown in FIG. 5, the first light emitting element 81 of the first photocoupler 71 has a resistance R 1, the second light emitting element 82 of the second photocoupler 72 has a resistance R 2, and the third light emitting of the third photocoupler 73. The element 83 is connected in series with a resistor R3. The resistor R1, the resistor R2, and the resistor R3 are provided as a current-voltage conversion unit R for limiting the current and converting the current flowing through each light emitting element into a voltage. In other words, a resistor as the current-voltage conversion unit R is provided for each light emitting element.

  The voltage Va between the first light emitting element 81 and the resistor R1, the voltage Vb between the second light emitting element 82 and the resistor R2, and the voltage Vc between the third light emitting element 83 and the resistor R3 are respectively controlled by the control unit 2 (CPU 21). ). The control unit 2 (CPU 21) includes an AD conversion circuit (not shown), and recognizes the magnitudes of the voltage Va, the voltage Vb, and the voltage Vc converted by each current-voltage conversion unit R (step # 11).

  Here, for each of the voltage Va, the voltage Vb, and the voltage Vc, a threshold for determining whether or not a current is flowing through the light emitting element is provided. Voltage when the first light emitting element 81 is turned on for the first time after a set voltage (for example, DC 24V) of the secondary DC voltage V2 is applied to the series circuit of the first light emitting element 81 of the new first photocoupler 71 and the resistor R1. The value of Va (initial voltage) may be used as the threshold value of the first light emitting element 81. Further, the voltage Vb (when the second light emitting element 82 is turned on for the first time by applying the voltage of the upper limit value to the series circuit of the constant voltage diode ZD, the second light emitting element 82 of the new second photocoupler 72, and the resistor R2. The value of the initial voltage may be set as the threshold value of the second light emitting element 82. The third light emitting element 83 is turned on for the first time by turning on the transistor Tr1 while applying the set voltage of the secondary DC voltage V2 to the series circuit of the third light emitting element 83, the resistor R3 and the transistor Tr1 of the new third photocoupler 73. The value of the voltage Vc (initial voltage) at that time may be used as the threshold value of the third light emitting element 83. In other words, the initial voltage of each light emitting element may be used as the threshold value of each light emitting element. Threshold data 31 indicating the threshold value of each light emitting element is stored in the storage unit 3 in a nonvolatile manner (see FIG. 5).

  Then, the control unit 2 (CPU 21) determines whether each light emitting element is turned on or off (step # 12). The control unit 2 repeats this determination periodically (at a constant cycle). Specifically, the control unit 2 determines that a light emitting element whose voltage exceeds a threshold value is a light emitting element that is turned on, and determines that a light emitting element whose corresponding voltage does not exceed a threshold value is a light emitting element that is turned off.

  Then, the CPU 21 causes the timer 23 to measure the lighting time of the light emitting element that is lit (step # 13). When the CPU 21 recognizes lighting of the light emitting element in a state where the lighting time is not measured, the CPU 21 causes the timer unit 23 to start measuring the lighting time of the light emitting element. When the lighting of the light emitting element in the state of counting the lighting time is recognized, the CPU 21 causes the time counting unit 23 to keep counting the lighting time of the light emitting element. When recognizing that the light emitting element that has been counting the lighting time until Step # 13 is turned off, the CPU 21 ends the lighting time of the light emitting element.

  Moreover, the control part 2 (CPU21) is based on the output (the magnitude | size of the voltage Va, the voltage Vb, and the voltage Vc) of each current-voltage conversion part R, and the electric current which flows into the light emitting element currently timed (lighted) Is determined (step # 14). Resistance values of the resistor R1, the resistor R2, and the resistor R3 are determined. Therefore, the control unit 2 obtains the magnitude of the current flowing through the first light emitting element 81 by the voltage Va / resistance R1. Further, the control unit 2 obtains the magnitude of the current flowing through the second light emitting element 82 by the voltage Vb / resistance R2. Further, the control unit 2 obtains the magnitude of the current flowing through the third light emitting element 83 by the voltage Vc / resistance R3.

  Then, the control unit 2 causes the storage unit 3 to update the accumulated time data 33 (step # 15). The accumulated time data 33 is data indicating the accumulated lighting time of each light emitting element. The control unit 2 obtains a value obtained by adding the time counted to the cumulative lighting time corresponding to the light emitting element that has finished counting the lighting time among the cumulative lighting times included in the cumulative time data 33, and the total to the obtained value. The storage unit 3 is made to update the time data 33. That is, the storage unit 3 stores the cumulative lighting time of each light emitting element based on the timing result of the timing unit 23.

  Further, the control unit 2 stores the magnitude of the current flowing through the light emitting element that is timed (lighted) as the current value data 32 (step # 16). The current value data 32 is stored for obtaining an average value of currents of the respective light emitting elements. Since the storage capacity of the storage unit 3 is also limited, an upper limit may be set for the number of current values stored for each light emitting element, the oldest record may be erased, and the calculated current value may be rewritten. . Moreover, the control part 2 may memorize | store the average value in a lighting period in the memory | storage part 3 as a magnitude | size of the electric current which flows into a light emitting element. After step # 16, the flow returns to step # 11.

(Life judgment)
Next, an example of the flow of determining the lifetime of each photocoupler according to the embodiment will be described with reference to FIGS. FIG. 7 is a flowchart illustrating an example of a flow of determining the lifetime of each photocoupler according to the embodiment. FIG. 8 is a diagram illustrating an example of the time setting data 34 for determining the turn-on time of each light emitting element.

  First, in the printer 100 according to the embodiment, the notification unit (details will be described later), the power supply board 6, the timekeeping unit 23, the storage unit 3, the operation panel 4, and the control unit 2 determine the lifetime of each photocoupler. It functions as the device 1.

  Then, the input receiving unit 42 of the operation panel 4 receives an execution instruction for determining the lifetime of each photocoupler mounted on the power supply substrate 6. The start in FIG. 7 is a time point at which the lifetime determination process for each photocoupler is started based on the execution instruction.

  First, the control unit 2 obtains an average value of the magnitudes of currents flowing through the respective light emitting elements based on the current value data 32 of the storage unit 3 (step # 21). Then, the control unit 2 determines the turn-on time of each light emitting element based on the obtained average values (step # 22).

  Specifically, the control unit 2 determines the lighting time of each light emitting element based on the time setting data 34 shown in FIG. The deterioration of the light emitting element progresses faster as the current during lighting increases. Therefore, the time setting data 34 is determined so that the lightable time is longer as the average value is smaller, and the lightable time is shorter as the average value is larger.

  In the time setting data 34 shown in FIG. 8, the lighting possible time with respect to the average value of the current is determined for each photocoupler. This is because the photocouplers mounted on the power supply board 6 are not necessarily of the same specifications (specifications).

  In the time setting data 34 of FIG. 8, regarding the first photocoupler 71, A01 is an average value of the current flowing through the first light emitting element 81. A11 and A12 are current values that serve as boundaries in determining the lighting possible time. The relationship is A11 <A12. Further, since the lighting possible time is shortened as the average value increases, T11, T12, and T13 defined in FIG. 8 have a relationship of T13 <T12 <T11.

  In the time setting data 34 of FIG. 8, regarding the second photocoupler 72, A02 is an average value of the current flowing through the second light emitting element 82. A21 and A22 are current values that serve as boundaries in determining the lighting possible time. The relationship is A21 <A22. Further, since the lighting possible time is shortened as the average value increases, T21, T22, and T23 defined in FIG. 8 have a relationship of T23 <T22 <T21.

  In the time setting data 34 in FIG. 8, regarding the third photocoupler 73, A03 is an average value of the current flowing through the third light emitting element 83. A31 and A32 are current values that serve as boundaries in determining the lighting possible time. The relationship is A31 <A32. Further, since the lighting possible time is shortened as the average value increases, T31, T32, and T33 defined in FIG. 8 have a relationship of T33 <T32 <T31.

  In this way, the control unit 2 sets the lightable time for longer light emitting elements with a smaller average value, and sets the lightable time shorter for light emitting elements with a larger average value.

  Next, the controller 2 subtracts the cumulative lighting time of the corresponding light emitting element from the lighting possible time of each light emitting element, and obtains an estimated remaining time until the lifetime of each photocoupler expires (step # 23). Then, the control unit 2 causes the notification unit to notify each estimated remaining time as a life determination result (step # 24 → end).

  Here, the display panel 41 of the operation panel 4 can be used as a notification unit. In this case, the control unit 2 causes the display panel 41 to display the life determination result. The printing unit 5 can also be used as a notification unit. In this case, the control unit 2 causes the printing unit 5 to print the life determination result. Further, the communication unit 24 may be used as a notification unit. In this case, the control unit 2 causes the communication unit 24 to transmit data indicating the life determination result to the predetermined computer 200.

  In the second photocoupler 72 for detecting overvoltage, the cumulative lighting time may be zero. In other words, the voltage Vb output from the current-voltage conversion unit R of the second light emitting element 82 may not exceed the threshold value determined for the second light emitting element 82. In this case, a predetermined estimated remaining time may be notified as a life determination result. The predetermined estimated remaining time may be appropriately determined based on the data sheet of the second photocoupler 72.

  In this way, the power supply life determination device 1 according to the embodiment converts the input alternating current into direct current and outputs the notification section (display panel 41, printing section 5, communication section 24) for notifying the life determination result. And a photo-coupler (first photo-coupler 71, which includes a light-emitting element and a light-receiving element, and the light-receiving element is connected to the controller 62. The controller 62 includes a controller 62 that adjusts the output voltage by controlling the switching time or frequency of the switching element Q1. Power supply board 6 including a plurality of second photocouplers 72 and third photocouplers, a time measuring unit 23 for measuring the lighting time of each light emitting element, and a cumulative lighting time of each light emitting element based on the time measurement result of the time measuring unit 23 The storage unit 3 to be operated, the operation panel 4 for accepting an execution instruction for determining the lifetime of the photocoupler, and the lighting time of each light emitting element when the execution instruction is given. A control unit 2 for subtracting the corresponding cumulative lighting time from the lighting possible time, obtaining an estimated remaining time until the lifetime of each photocoupler is exhausted, and notifying each of the estimated remaining time as a life determination result to the notification unit; including.

  Thereby, information on the lifetime of each photocoupler provided on the power supply substrate 6 can be easily obtained. Further, even if the lighting frequency of each photocoupler is different, accurate information regarding the lifetime of each photocoupler can be transmitted to the user. Therefore, it can be determined whether or not the power supply board 6 can be reused based on the life determination result. Further, since information on the lifetime of each photocoupler can be obtained, it is possible to identify a photocoupler that has deteriorated and needs to be replaced, and extend the lifetime of the power supply substrate 6. Therefore, the amount of waste can be reduced by reusing the power supply board 6 and extending the life, thereby contributing to environmental protection and resource saving.

  Moreover, the current-voltage conversion part R is provided with respect to each light emitting element. Based on the output voltage of each current-voltage conversion unit R, the control unit 2 obtains the magnitude of the current flowing through each light emitting element and its average value, sets the lightable element with a smaller average value to set the lighting time longer, A light-emitting element having a larger value is set to have a shorter lighting time. Accordingly, it is possible to determine the turn-on time of each light emitting element in consideration of the fact that the larger the flowing current is, the easier the deterioration of the light emitting element is due to heat generation.

  The power supply board 6 includes an insulating transformer L1. Switching element Q1 is connected to primary coil L11 to insulating transformer L1. Of the plurality of photocouplers, the light emitting element (first light emitting element 81) of one photocoupler (first photocoupler 71) emits light based on the output of the power supply substrate 6 and generates a feedback signal. The controller 62 turns on / off the switching element Q1 by a PWM signal corresponding to the output of the light receiving element that receives the feedback signal. Thereby, the information regarding the lifetime of the photocoupler for returning from the secondary side of the switching power supply to the primary side can be obtained.

  In addition, among the plurality of photocouplers, the light emitting element (second light emitting element 82) of one photocoupler (second photocoupler 72) emits light based on the output voltage of the power supply board 6, and the output voltage of the power supply board 6 Emits light and emits an overvoltage detection signal when becomes equal to or greater than a predetermined upper limit. When the light receiving element that receives the overvoltage detection signal receives the overvoltage detection signal, the controller 62 turns off the switching element Q1 and stops the voltage output. Thereby, it is possible to detect the overvoltage of the secondary side output of the switching power supply and obtain information on the lifetime of the photocoupler for transmitting the overvoltage to the primary side.

  In addition, among the plurality of photocouplers, the light emitting element (third light emitting element 83) of one photocoupler (third photocoupler 73) emits light based on the output voltage of the power supply substrate 6, and is controlled by the control unit 2. A mode switching signal is issued. The controller 62 generates a PWM signal to turn ON / OFF the switching element Q1, and based on the mode switching signal received by the light receiving element that receives the mode switching signal, the frequency of the PWM signal is set to a frequency corresponding to the mode. Thus, information on the lifetime of the photocoupler for transmitting mode switching such as the power saving mode and the normal mode to the primary side can be obtained.

  Further, the image forming apparatus includes a power supply life determination device 1. According to this configuration, it is possible to provide an image forming apparatus (printer 100) that can easily determine whether to reuse the power supply substrate 6. In addition, it is possible to provide an image forming apparatus that notifies a photocoupler that is highly required to be replaced among a plurality of photocouplers on the power supply substrate 6.

  Although the embodiments of the present invention have been described above, the scope of the present invention is not limited to these embodiments, and various modifications can be made without departing from the spirit of the invention.

  The present invention can be used in a power supply board and an image forming apparatus including the power supply board.

DESCRIPTION OF SYMBOLS 100 Printer (image forming apparatus) 1 Power supply life judgment apparatus 2 Control part 23 Timekeeping part 24 Communication part (notification part) 3 Storage part 4 Operation panel 41 Display panel (notification part)
DESCRIPTION OF SYMBOLS 5 Printing part (notification part) 6 Power supply board 62 Controller 71 1st photocoupler 72 2nd photocoupler 73 3rd photocoupler 81 1st light emitting element 82 2nd light emitting element 83 3rd light emitting element 91 1st phototransistor (light receiving element) )
92 Second phototransistor (light receiving element)
93 Third phototransistor (light receiving element)
L1 Insulation transformer L11 Primary coil Q1 Switching element R Current-voltage converter

Claims (6)

An informing unit for informing a life judgment result;
It has a controller that converts the input alternating current into direct current and outputs it, and controls the switching time or frequency of the switching element to adjust the output voltage. The controller includes a light emitting element and a light receiving element, and the light receiving element is connected to the controller. A power supply board including a plurality of photocouplers,
A timing unit for measuring the lighting time of each of the light emitting elements;
A storage unit that stores a cumulative lighting time of each light emitting element based on a timing result of the timing unit;
An operation panel for accepting an execution instruction for determining the lifetime of the photocoupler;
When the execution instruction is made, the lighting time of each light emitting element is determined, the corresponding cumulative lighting time is subtracted from the lighting time, and the estimated remaining time until the lifetime of each photocoupler is obtained. And a control unit that causes the notification unit to notify each estimated remaining time as the lifetime determination result. A current-voltage converter is provided for each of the light-emitting elements;
The control unit obtains the magnitude of the current flowing through each of the light emitting elements and the average value thereof based on the output voltage of each of the current voltage conversion units, and the light emitting element having a smaller average value increases the lighting time. The power supply life determination apparatus according to claim 1, wherein the light-emitting element having a larger average value is set so that the lightable time is shorter. The power supply board includes an insulating transformer,
The switching element is connected to a primary coil to the isolation transformer;
Of the plurality of photocouplers, the light emitting element of one of the photocouplers emits light based on the output of the power supply board to emit a feedback signal,
The power source life determination apparatus according to claim 1, wherein the controller turns on / off the switching element by a PWM signal corresponding to an output of the light receiving element that receives the feedback signal. Among the plurality of photocouplers, the light emitting element of one of the photocouplers emits light based on the output voltage of the power supply substrate, and emits light when the output voltage of the power supply substrate exceeds a predetermined upper limit value. To issue an overvoltage detection signal,
4. The controller according to claim 1, wherein when the light receiving element that receives the overvoltage detection signal receives the overvoltage detection signal, the controller turns off the switching element and stops voltage output. The power supply life judging device according to the item. Among the plurality of photocouplers, the light emitting element of one of the photocouplers emits light based on the output voltage of the power supply substrate, and emits a mode switching signal under the control of the control unit,
The controller generates a PWM signal to turn on / off the switching element, and based on the mode switching signal received by the light receiving element that receives the mode switching signal, the frequency of the PWM signal is set according to the mode. The apparatus according to claim 1, wherein the apparatus is a frequency.   An image forming apparatus including the power supply life determination apparatus according to claim 1.

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