Power supply device and image forming apparatus

Abstract

To detect that DC is input to a power supply device to which normally AC is input.SOLUTION: A power supply device 160 is a power supply device 160 that receives input of AC through an input power line 63 and generates desired voltage, and comprises: a current sensor 108 that detects the AC input to the input power line 63; and a DC detection circuit 140 that, when the alternating current is no longer detected by the current sensor 108, starts detecting whether DC is input from the input power line 63.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present disclosure relates to a power supply device and an image forming apparatus. [Background technology]

[0002] 2. Description of the Related Art Conventionally, image forming apparatuses constantly check the power supply status from an external power source to avoid input switching in a state where no power is being supplied and to display the power status on a panel.

[0003] In this case, as described in Patent Document 1, for example, by measuring the value of the current flowing through the power line with a current measuring device, it is possible to determine whether or not a current is flowing through the power line. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Utility Model Application Publication No. 1-124572 Summary of the Invention [Problem to be solved by the invention]

[0005] However, a power conditioner that converts direct current (DC) from a power storage system or solar power generation or the like into alternating current (AC) may be connected as an external power source to the image forming apparatus. If the power conditioner serving as an external power source fails, DC is input to the image forming apparatus.

[0006] In such a case, conventional current measuring devices cannot recognize DC, and therefore cannot display that DC is being input to the image forming apparatus, making it impossible to check for abnormalities in the power conditioner.

[0007] Therefore, one or more aspects of the present disclosure are characterized in that a power supply device that normally receives AC input is able to detect that DC is being input. [Means for solving the problem]

[0008] A power supply device according to one aspect of the present disclosure is a power supply device that receives an AC input via an input power line and generates a desired voltage, the power supply device including: an AC detection unit that detects the AC input to the input power line; and a DC detection unit that starts detecting whether or not a DC is being input from the input power line when the AC detection unit no longer detects AC. a control unit that controls the DC detection unit so as not to allow a current from the input power line to flow to the DC detection unit when an AC is detected by the AC detection unit, and controls the DC detection unit so as to allow a current from the input power line to flow to the DC detection unit when an AC is no longer detected by the AC detection unit; Equipped with The DC detection unit detects that a DC current is being input from the input power supply line when a current flows from the input power supply line. Characterized by

[0009] An image forming apparatus according to one aspect of the present disclosure includes the above-described power supply device. Effect of the Invention

[0010] According to one or more aspects of the present disclosure, a power supply device that normally receives AC input can detect that DC is being input. [Brief description of the drawings]

[0011] [Figure 1] 1 is a perspective view showing an external appearance of an image forming apparatus according to an embodiment; [Diagram 2] 1 is a cross-sectional view showing a schematic configuration of an image forming apparatus. [Diagram 3] FIG. 2 is a side view showing an example of installation of the image forming apparatus. [Figure 4] FIG. 2 is a block diagram illustrating a schematic configuration of a control system of the image forming apparatus. [Diagram 5] 2 is a wiring diagram for illustrating wiring for supplying power to the image forming apparatus. FIG. [Figure 6] FIG. 1 is a circuit diagram of a DC detection circuit. [Figure 7] 4 is a graph for explaining a state of a signal on a signal line. [Figure 8]6 is a flowchart showing an operation of monitoring power input to an input power line. [Figure 9] 1A and 1B are block diagrams illustrating an example of a hardware configuration. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] FIG. 1 is a perspective view showing the appearance of an image forming apparatus 100 according to an embodiment. The image forming apparatus 100 here is a multi-function printer (MFP). As shown in FIG. 1, an image forming apparatus 100 includes a user interface (UI) 101 that functions as a main display unit and a main input unit.

[0013] FIG. 2 is a cross-sectional view showing a schematic configuration of the image forming apparatus 100. As shown in FIG. Here, the image forming apparatus 100 according to the embodiment is assumed to have, for example, a tandem type printer mechanism, but is not limited to this example.

[0014] The image forming apparatus 100 generally includes a paper feed section 10, an image forming mechanism section 20, a fixing section 40, and a discharge section 50. The image forming apparatus 100 forms an image on paper S as a recording medium. Here, the section including the paper feed section 10, the image forming mechanism section 20, the fixing section 40, and the discharge section 50, and which executes the process of forming an image on the medium, is also referred to as the image forming apparatus main body.

[0015] The paper feed section 10 conveys one sheet of paper S. The paper feed section 10 includes a paper feed cassette 11, a paper feed roller 12, pairs of transport rollers 13A, 13B, 14A, and 14B, and pairs of registration rollers 15A and 15B.

[0016] The paper feed cassette 11 accommodates the paper S therein. The paper feed roller 12 rotates to take out one sheet S from the sheets S stored in the paper feed cassette 11 and feeds the sheet S to the subsequent stage.

[0017] The conveying roller pairs 13A, 13B, 14A, and 14B convey a sheet of paper S supplied by the paper feed roller 12 to the registration roller pairs 15A and 15B. The pair of registration rollers 15A and 15B corrects the inclination of the conveyed sheet of paper S, and supplies the sheet of paper S to the image forming mechanism 20.

[0018] The image forming mechanism section 20 includes four color image forming units 21K, 21Y, 21M, and 21C. The image forming unit 21K forms a black image, the image forming unit 21Y forms a yellow image, the image forming unit 21M forms a magenta image, and the image forming unit 21C forms a cyan image.

[0019] The image forming mechanism 20 also includes print heads 22K, 22Y, 22K, and 22C as exposure units that come into contact with the image forming units 21K, 21Y, 21M, and 21C, respectively, when the top cover 60 of the image forming apparatus 100 is closed.

[0020] Here, the image forming units 21K, 21Y, 21M, and 21C have the same configuration except that the colors of the toners used as the developers are different, so the image forming unit 21K will be used for the explanation.

[0021] The image forming unit 21K is provided with a toner cartridge 23 that contains toner, and the toner is supplied from the toner cartridge 23 to the image forming unit 21K.

[0022] Further, the image forming unit 21K includes a photoconductor drum 24 as an image carrying portion, a charger 25 as a charging portion, a developing roller 26 as a developing portion, and a cleaner 27 as a removing portion.

[0023] The peripheral surface of the photoconductor drum 24 is made of a photoconductive material. The charger 25 uniformly charges the photoconductor drum 24. The uniformly charged photoconductor drum 24 is exposed to light by the print head 22K, whereby an electrostatic latent image is formed on the photoconductor drum 24.

[0024] The developing roller 26 adheres toner to the photoconductor drum 24 on which the electrostatic latent image has been formed, thereby forming a toner image as a developer image on the photoconductor drum 24. The cleaner 27 scrapes off dirt such as toner remaining on the photoconductor drum 24 after the toner image has been transferred from the photoconductor drum 24 to a sheet of paper S, as described below.

[0025] In the manner described above, the toner images formed by the image forming units 21K, 21Y, 21M, and 21C are transferred onto a sheet of paper S transported by the transfer belt 29 by the transfer devices 28K, 28Y, 28M, and 28C, which serve as transfer sections.

[0026] The transfer belt 29 is an unsupported belt, and is stretched over a drive roller 30 and a driven roller 31 . The driving roller 30 rotates to transport a sheet of paper S on the transfer belt 29 from the pair of registration rollers 15A and 15B toward the fixing unit 40. The driven roller 31 rotates in the same direction as the driving roller 30 as the driving roller 30 rotates.

[0027] The fixing section 40 fixes the toner image transferred onto one sheet of paper S by the image forming mechanism section 20 onto that sheet of paper S. The fixing unit 40 includes a heating roller 41 and a pressure roller 42 .

[0028] The heating roller 41 has a heat source such as a heater inside, and melts the toner image transferred onto the sheet of paper S. The pressure roller 42 presses the sheet of paper S toward the heating roller 41, thereby fixing the toner image melted by the heating roller 41 onto the sheet of paper S. The sheet of paper S on which the toner image has been fixed in the above manner is discharged in the direction of a discharge section 50.

[0029] The discharge section 50 includes pairs of discharge rollers 51A, 51B, 52A, 52B, 53A, and 53B, and conveys a sheet of paper S from the fixing section 40 and discharges it outside the image forming apparatus 100.

[0030] FIG. 3 is a side view showing an example of installation of the image forming apparatus 100. As shown in FIG. In FIG. 3, the image forming apparatus 100 includes an image forming mechanism 20 that forms an image on a recording sheet, an image reading section 61 that reads an image from an original, and a facsimile communication control circuit 62.

[0031] The image forming apparatus 100 also includes a controller 120 . The controller 120 controls the image forming mechanism 20, the image reading unit 61, and the facsimile communication control circuit 62, thereby controlling the processing in the image forming apparatus 100. For example, the controller 120 controls processing such as temporarily storing image data of an image read by the image reading unit 61 and sending the image data to the image forming mechanism 20 or the facsimile communication control circuit 62.

[0032] In addition, a user interface 103 (hereinafter referred to as "UI 103") is located at the front of the upper part of image forming device 100, for instructing items of processing operations including image reading processing, copying processing, image formation processing, or transmission / reception processing, for instructing detailed settings of each processing operation, and for displaying the status of image forming device 100.

[0033] A sub-panel 110 (see FIG. 4), which will be described later, is provided adjacent to the UI 103. In this embodiment, the sub-panel 110 does not belong to the UI 103 and functions as an independent user interface.

[0034] The controller 120 is connected to a communication network such as the Internet, and the facsimile communication control circuit 62 is connected to a telephone line.

[0035] The controller 120 is adapted to be able to communicate with a PC (Personal Computer) 1 serving as a host computer, which will be described later, via, for example, a communication network. For example, the controller 120 controls processes such as receiving image data from a PC 170 (see FIG. 4) and executing facsimile reception and transmission using a telephone line via a facsimile communication control circuit 62.

[0036] In this embodiment, the image forming apparatus 100 can use the image forming mechanism unit 20, the image reading unit 61 and the facsimile communication control circuit 62 to perform processing operations as services including scanning, copying, printing, facsimile transmission, facsimile reception and printing after reception.

[0037] In the image forming apparatus 100, a power outlet 64 is attached to the end of an input power line 63. The outlet 64 is inserted into a wiring plate 71 of a commercial power source 70 that is wired to a wall W, so that the image forming apparatus 100 receives power from the commercial power source 70 . In this embodiment, it is assumed that commercial power supply 70 outputs power from a power conditioner that converts DC output from a solar power generation system or a power storage system into AC.

[0038] For example, when the outlet 64 is not plugged into the wiring plate 71 , power from the commercial power source 70 is not supplied to the image forming apparatus 100 . In addition, even if the outlet 64 is plugged into the wiring plate 71, if, for example, an extension cord or other power strip with an off timer function is interposed, power may not be supplied to the image forming apparatus 100 even if it appears that power is being supplied. Furthermore, in this embodiment, if a power conditioner functioning as the commercial power supply 70 breaks down, DC may be supplied to the image forming apparatus 100.

[0039] FIG. 4 is a block diagram showing a schematic configuration of a control system of the image forming apparatus 100. As shown in FIG. The sub-panel 110 includes a solar panel 111 , a power storage device 112 , a control unit 113 , and a display unit 114 .

[0040] The solar panel 111 is a photovoltaic power generation device that functions as a power generation unit that uses light energy from the sun and generates electricity by applying the photovoltaic effect. The electricity generated by the solar panel 111 is sent to the power storage device 112.

[0041] The power storage device 112 is charged by solar power generation by the solar panel 111. In other words, the power storage device 112 is a power storage unit that accumulates electricity transmitted from the solar panel 111.

[0042] The power storage device 112 supplies electricity to the control unit 113. Here, the power storage device supplies electricity only to the control unit 113, and therefore the power storage device 112 serves as an independent power source for the sub-panel 110.

[0043] The control unit 113 controls the processing on the sub-panel 110 . Here, the control unit 113 controls the display unit 114 to change the content displayed on the display unit 114. For example, as described below, when it is detected that DC is being input to the input power line 63, the display unit 114 displays that DC is being input.

[0044] A part or all of the control unit 113 described above can be configured, for example, as shown in FIG. 9(A), by a memory 1 and a processor 2 such as a CPU (Central Processing Unit) that executes a program stored in the memory 1.

[0045] In addition, a part or all of the control unit 113 may be configured with a processing circuit 3 such as a single circuit, a composite circuit, a processor operated by a program, a parallel processor operated by a program, an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array), for example, as shown in FIG. 9(B). As described above, the control unit 113 can be realized by a processing circuit network.

[0046] The display unit 114 displays various contents in response to instructions from the control unit 113 . Note that display unit 114 uses a liquid crystal display device without a backlight to achieve the lowest possible power consumption at present, but display unit 114 is not limited to this example. For example, display unit 114 may have a backlight depending on the amount of power stored in power storage device 112 or the power generation capacity of solar panel 111, and may be configured with LEDs (Light Emitting Diodes). Furthermore, display unit 114 may be a touch panel equipped with an operation function as an input unit.

[0047] The sub-panel 110 may be fixed in a state housed in the housing 102 of the image forming apparatus 100, or may be detachable from the housing 102. When the sub-panel 110 is detachable from the housing 102, the wiring including the bus 80 for communicating with the inside of the housing 102 of the image forming device 100, the signal line 81 for current monitoring, and the signal line 82 for transmitting the DC detection result may be wired or wireless.

[0048] In addition, although the sub-panel 110 is disposed near the UI 103 here, the attachment position of the sub-panel 110 is not limited to this example. The sub-panel 110 may be attached not only around the UI 103 but also anywhere on the housing 102, but is preferably attached in a position that is easily visible to the user. Furthermore, if the sub-panel 110 is made detachable, multiple temporary installation locations may be prepared.

[0049] As described above, sub-panel 110 operates with power received from power storage device 112, which is an independent power source, without receiving power supply from housing 102 of image forming apparatus 100. Sub-panel 110 functions as an information display device that displays notification information on display unit 114 based on operation information received from controller 120 via bus 80. Here, the operation information is, for example, operation mode information indicating the operation mode of image forming apparatus 100, and the notification information is mainly power value information indicating the power value.

[0050] The communication network is connected to the controller 120 of the image forming apparatus 100. A PC 170 is connected to the communication network as a terminal device that can be a source of image data.

[0051] The controller 120 is connected to the facsimile communication control circuit 62 via a bus 83, to the image reading unit 61 via a bus 84, to the image forming mechanism unit 20 via a bus 85, and to the UI 103 via a bus 86, respectively. In other words, the controller 120 mainly controls each processing unit of the image forming apparatus 100 . Here, each of the buses 83 to 86 functions as a data bus or a control bus. In addition, the controller 120 is connected to the control unit 113 of the sub-panel 110 via a bus 80 .

[0052] The image forming apparatus 100 includes a power supply board 130 . The power supply board 130 is connected to the controller 120 via a signal line 87 . The power supply board 130 receives power from a commercial power supply 70 via a wiring plate 71 and a socket 64 and an input power line 63 .

[0053] Power supply lines 90, 91, 92, 93, and 94 that supply power independently to the controller 120, the facsimile communication control circuit 62, the image reading unit 61, the image forming mechanism unit 20, and the UI 103 are connected to the power supply board 130, respectively. Therefore, the controller 120 can perform so-called partial power saving control, which supplies power to and limits the power supply to each of these units individually.

[0054] The image forming apparatus 100 includes a solar panel 104 . The solar panel 104 may be attached to, for example, all or part of the surface of the housing 102 of the image forming apparatus 100, or may be installed away from the housing 102.

[0055] The solar panel 104 is connected to the power storage device 105 via a dedicated wiring 95. The electricity generated by the solar panel 104 is sent to the power storage device 105 and stored therein.

[0056] The power stored in the power storage device 105 can be sent to the controller 120 via a power supply line 96 .

[0057] The controller 120 includes a main controller 121 , a sub-controller 122 , and a power supply switching unit 123 . In the normal mode, the main controller 121 controls the processing in the image forming apparatus 100 . The sub-controller 122 controls the processing in the image forming apparatus 100 in the normal mode and in the sleep 0 mode, which is a power saving mode.

[0058] The power supply switching unit 123 switches the source of power supply to the sub-controller 122. For example, in the normal mode, the power supply switching unit 123 connects the power supply board 130, which is a main power supply unit, to the sub-controller 122, and in the sleep 0 mode, the power supply switching unit 123 connects the power storage device 105, which is a secondary power supply unit, to the sub-controller 122.

[0059] Therefore, in the normal mode, the power supply board 130 serves as the power supply source, and power is supplied to the main controller 121 and the sub-controller 122. On the other hand, in the sleep 0 mode, the power storage device 105 serves as the power supply source, and power is supplied to the sub-controller 122.

[0060] FIG. 5 is a wiring diagram for explaining the schematic wiring for supplying power to the image forming apparatus 100. As shown in FIG. An outlet 64 is provided at one end of an input power line 63 that supplies power to the image forming apparatus 100, and the outlet 64 is inserted into a wiring plate 71 of a commercial power source 70 that is wired to a wall surface W. The other end of the input power line 63 is connected to a ground fault circuit interrupter 131 of a power supply board 130.

[0061] The earth leakage breaker 131 is connected upstream of the main power switch 106 . Earth leakage circuit breaker 131 monitors leakage current in the power wiring inside image forming apparatus 100. If an electric leakage current is detected, earth leakage circuit breaker 131 cuts off the power supply, and thus the power supply is cut off at the most input end of image forming apparatus 100.

[0062] The main power switch 106 has a role of supplying power from the commercial power source 70 to the image forming apparatus 100 at the user's discretion. The main power switch 106 is connected to an LVPS (Low Voltage Power Supply) 133 via a 0W switch 132.

[0063] The 0w switch 132 is turned on or off based on an instruction signal from the sub-controller 122. Here, the 0w switch 132 is a switch that is controlled to be turned on / off by software. For example, when the image forming apparatus 100 transitions from the normal mode to the sleep 0 mode, the 0w switch 132 is turned off, and the contacts of the power supply switching unit 123 are switched to supply power to the sub-controller 122 from the power storage device 105. As a result, in the sleep 0 mode, power is not supplied from the commercial power supply 70 to the main controller 121 and the sub-controller 122, and the power consumption on the commercial power supply 70 side becomes approximately zero.

[0064] The image forming apparatus 100 is equipped with a recovery button 107. When the recovery button 107 is pressed, a recovery signal for returning from the sleep 0 mode to the normal mode is sent to the sub-controller 122 via a signal line 88. Upon receiving the recovery signal, the sub-controller 122 turns on the 0w switch 132, switches the contacts of the power supply switching unit 123, supplies power from the LVPS 133, and starts up the main controller 121. This causes the image forming apparatus 100 to recover to the normal mode.

[0065] A current sensor 108 is provided on the input power line 63 further upstream of the earth leakage breaker 131 . The current sensor 108 is an AC detection unit that detects the AC input to the input power line 63. Here, the current sensor 108 is a magnetic field detection type sensor that uses a coil to detect a magnetic field generated by the AC flowing through the input power line 63. For example, current sensor 108 measures the AC flowing through input power line 63 based on the relationship between the AC flowing through input power line 63 and the magnetic field, and outputs a measurement value signal indicating the measured value to control unit 113 of sub-panel 110 via signal line 81. In sub-panel 110, control unit 113 constantly monitors the measurement value signal.

[0066] In this embodiment, since detecting the voltage after rectification or after boosting by a PFC (Power Factor Correction) circuit or the like results in a large power loss, a DC detection circuit 140 that detects direct current is provided upstream of the main power switch 106. The DC detection circuit 140 is connected to the control unit 113 of the sub-panel 110 and the power storage device 112.

[0067] The DC detection circuit 140 is a DC detection unit that starts detecting whether or not a DC current is being input from the input power supply line 63 when the current sensor 108 no longer detects an AC current.

[0068] FIG. 6 is a circuit diagram of the DC detection circuit 140. The DC detection circuit 140 is connected to the input power line 63 at two positions P1 and P2, which are located further upstream than the earth leakage breaker 131 shown in FIG.

[0069] The DC detection circuit 140 includes an electric wire 141 , a limiting resistor 142 , a DC detection switch 143 , a phototriac 144 , a limiting resistor 145 , and a capacitor 146 .

[0070] The electric wire 141 is provided so as to connect the input power line 63 between a position P1 and a position P2. The electric wire 141 is provided with a DC detection switch 143 for connecting or disconnecting the electric wire 141 .

[0071] The DC detection switch 143 is connected to the control unit 113 of the sub-panel 110 via a signal line 82. When AC is no longer detected by the current sensor 108 shown in FIG. 5, the control unit 113 turns on the DC detection switch 143 to detect DC.

[0072] The input side of the phototriac 144 is connected to an electric wire 141, which is provided with a limiting resistor 142. Therefore, when DC flows through the input power line 63, the DC is input to the DC detection circuit 140, and the phototriac 144 turns on.

[0073] The output side of the phototriac 144 is connected to a power supply line 97 via a limiting resistor 145. The power supply line 97 is connected to the power storage device 112 of the sub-panel 110. In addition, the output side of the phototriac 144 is connected to ground. The limiting resistor 145 is connected to the power supply line 97 , the phototriac 144 , the capacitor 146 , and the signal line 89 . Therefore, when the phototriac 144 is off, the power from the power supply line 97 flows through the limiting resistor 145 to the signal line 89, and the control unit 113 of the sub-panel 110 detects an on signal. On the other hand, when the phototriac 144 is on, the power from the power supply line 97 is directed to the ground via the phototriac 144, and the control unit 113 of the sub-panel 110 detects an off signal.

[0074] When the control unit 113 detects an ON signal on the signal line 89 after the DC detection switch 143 is turned on, it can detect that DC is not flowing, and when the control unit 113 detects an OFF signal on the signal line 89, it can detect that DC is flowing.

[0075] As described above, when AC is detected by the current sensor 108, the control unit 113 controls the DC detection circuit 140 so as not to allow current to flow from the input power line 63 to the DC detection circuit 140, and when AC is no longer detected by the current sensor 108, the control unit 113 controls the DC detection circuit 140 so as to allow current to flow from the input power line 63 to the DC detection circuit 140. Specifically, the DC detection circuit 140 includes an electric wire 141 that connects between a first position P1 and a second position P2 provided on the input power line 63. The electric wire 141 is provided with a DC detection switch 143 that is a switch that connects or disconnects the electric wire 141. When AC is detected by the current sensor 108, the control unit 113 disconnects the electric wire 141 using the DC detection switch 143, and when AC is no longer detected by the current sensor 108, the control unit 113 connects the electric wire 141 using the DC detection switch 143. When a current from the input power line 63 flows through the electric wire 141, the DC detection circuit 140 can detect that a DC is being input from the input power line 63.

[0076] Here, the current sensor 108, sub-panel 110, and power supply board 130 described above constitute a power supply device 160 that receives an AC input via the input power line 63 and generates a desired voltage.

[0077] The operation of the image forming apparatus 100 configured as above will be described below with reference to FIGS. Power is supplied from a wiring plate 71 of a commercial power source 70 wired to a wall W via a socket 64 and an input power line 63, and is output to the controller 120 via the LVPS 133 of the power supply board 130.

[0078] Between the input power line 63 and the LVPS 133, a ground fault circuit interrupter 131, a main power switch 106, and a 0W switch 132 are connected. Earth leakage circuit breaker 131 is directly connected to input power line 63, and monitors leakage current in the power wiring inside image forming apparatus 100. If an electric leakage current occurs, earth leakage circuit breaker 131 cuts off the power supply to image forming apparatus 100.

[0079] A main power switch 106 turns on or off the power from the commercial power source 70 to the image forming apparatus 100 at the user's discretion. The 0w switch 132 is connected to the sub-controller 122 of the controller 120 by a signal line 87, and in the normal mode, the 0w switch 132 is turned on by the sub-controller 122. As a result, in the normal mode, power is supplied from the commercial power supply 70 via the LVPS 133 to the main controller 121 and the sub-controller 122.

[0080] In the sleep 0 mode, the 0w switch 132 is turned off by the sub-controller 122. As a result, in the sleep 0 mode, power is not supplied to the image forming apparatus 100 from the commercial power source 70 even if the main power switch 106 is turned on.

[0081] A power supply switching unit 123 is connected to the sub-controller 122. In the normal mode, the 0W switch 132 is turned on, so that the sub-controller 122 is connected to the LVPS 133 and power is supplied from the commercial power supply 70 to the main controller 121 and the sub-controller 122 via the LVPS 133.

[0082] On the other hand, in the sleep 0 mode, the 0w switch 132 is turned off and the power source switching unit 123 is switched so that the power source of the sub-controller 122 becomes the power storage device 105 via the power supply line 96. The power storage device 105 is charged by the solar panel 104.

[0083] In the normal mode, the power supply board 130 supplies power to the facsimile communication control circuit 62, the image reading unit 61, the image forming mechanism unit 20, and the UI 103 via the power supply lines 90-94 under the control of the main controller 121.

[0084] In addition, by having the sub-controller 122 receive power from the power storage device 105, which is a secondary power supply unit separate from the power supply board 130, which is the main power supply unit, via the 0W switch 132 and the power supply switching unit 123, the power consumption in the energy-saving sleep 0 mode can be reduced to 0.1W or less.

[0085] A current sensor 108 is arranged on the input power line 63, and the current sensor 108 measures the AC flowing through the input power line 63 based on the relationship between the current and the magnetic field, and outputs the measurement value signal to the control unit 113 of the sub-panel 110 via the signal line 81.

[0086] Based on the measurement value signal from the current sensor 108, the control unit 113 of the sub-panel 110 generates an H signal when AC is flowing, and generates an L signal when AC is not flowing, and outputs the H signal to the sub-controller 122 via the signal line 87. The sub-controller 122 controls the 0W switch 132 and the power supply switching unit 123 based on the signal.

[0087] An earth leakage breaker 131 is connected to the input power line 63. The earth leakage breaker 131 is connected to the ground via a capacitor (not shown). Therefore, when AC is input to the input power line 63, a leakage current flows. Therefore, the current sensor 108 can detect AC if it is input to the input power line 63, whether the image forming apparatus 100 is in the normal mode or the sleep 0 mode.

[0088] If AC is not detected by the current sensor 108, the power supply from the input power line 63 to the earth leakage circuit breaker 131 has been cut off because the outlet 64 has been unplugged or the time has expired on a tap with an off timer function, or DC is being input due to a failure of the power conditioner functioning as the commercial power source 70.

[0089] On the other hand, when AC is detected by current sensor 108, it means that AC is being input to earth leakage breaker 131 from input power line 63. In such a case, control unit 113 calculates the power consumption based on the current value indicated by the current value signal acquired from current sensor 108. Display unit 114 displays the current operating mode and the calculated power consumption.

[0090] In this embodiment, DC detection circuit 140 detects DC only when current sensor 108 does not detect AC. Specifically, the control unit 113 and the DC detection switch 143 of the DC detection circuit 140 are connected by a signal line 82. When AC is detected by the current sensor 108, the control unit 113 outputs a signal H to the signal line 82 to turn off the DC detection switch 143, and when AC is not detected by the current sensor 108, the control unit 113 outputs a signal L to the signal line 82 to turn on the DC detection switch 143.

[0091] When the DC detection switch 143 is turned on, the phototriac 144 of the DC detection circuit 140 is connected to the input power line 63. When DC flows through the input power line 63, the phototriac 144 is turned on via the limiting resistor 142.

[0092] When the phototriac 144 is turned on, the current flowing from the power storage device 112 through the power supply line 97 flows to the ground, causing the signal line 89 to become an L signal.

[0093] On the other hand, when no DC current flows through the input power line 63, the phototriac 144 turns off and the current flowing through the power supply line 97 flows through the signal line 89, causing the signal line 89 to become an H signal.

[0094] Since the signal line 89 is connected to the control unit 113 of the sub-panel 110, the control unit 113 can grasp the state of the power input to the image forming apparatus 100 based on the signal of the signal line 89 and the current value signal from the current sensor 108. For example, when the current value signal from current sensor 108 indicates a current value, this means that AC is flowing in input power line 63. When the current value signal from current sensor 108 does not indicate a current value and signal line 89 is an H signal, this means that neither AC nor DC is flowing in input power line 63. When the current value signal from current sensor 108 does not indicate a current value and signal line 89 is an L signal, this means that DC is flowing in input power line 63.

[0095] FIG. 7 is a graph for explaining the state of the signals on the signal line 82 and the signal line 89. In FIG. 7, when AC is being input to the input power line 63, the control unit 113 turns off the DC detection switch 143 by outputting a signal H to the signal line 82. In this case, the signal line 89 becomes a signal H, and AC is flowing in the input power line 63.

[0096] On the other hand, when no AC is being input to the input power line 63, the control unit 113 turns on the DC detection switch 143 by outputting a signal L to the signal line 82. In this case, when the signal line 89 is a signal L, this means that DC is flowing in the input power line 63, and when the signal line 89 is a signal H, this means that neither AC nor DC is flowing in the input power line 63.

[0097] FIG. 8 is a flowchart showing an operation of monitoring the power input to the input power line 63 in the image forming apparatus 100. In FIG. First, the current sensor 108 detects the value of the AC current flowing through the input power line 63 (S10). A current value signal indicating the detected current value is sent to the control unit 113 of the sub-panel 110 via the signal line 81.

[0098] The control unit 113 determines whether or not AC is being input to the input power line 63 based on the current value signal from the signal line 81 (S11). If AC is being input (Yes in S11), the process proceeds to step S12, and if AC is not being input (No in S11), the process proceeds to step S14.

[0099] In step S12, the control unit 113 calculates the power consumption based on the current value indicated by the current value signal obtained from the current sensor . Then, the control unit 113 causes the display unit 114 to display the current operation mode and the power consumption (S13). Note that the operation mode may be notified from the sub-controller 122 via the bus 80.

[0100] On the other hand, in step S14, the control unit 113 outputs a signal L to the signal line 82 to turn on the DC detection circuit 140.

[0101] Then, the control unit 113 checks the state of the signal on the signal line 89 (S15). If the signal on the signal line 89 is High, the process proceeds to step S16, and if the signal on the signal line 89 is Low, the process proceeds to step S17.

[0102] In step S16, the control unit 113 determines that the power supply has been cut off by the tap with off timer function or that the outlet 64 has been unplugged from the wiring plate 71, and causes the display unit 114 to display that the power supply has been cut off and to check the outlet 64.

[0103] On the other hand, in step S17, since DC is being input due to a failure of the power conditioner which is commercial power supply 70, control unit 113 causes display unit 114 to display that DC is being input and that commercial power supply 70 is malfunctioning.

[0104] As described above, according to this embodiment, by arranging the DC detection circuit 140, which operates only when AC off is detected, upstream of the main power switch 106, it is possible to reduce power consumption due to DC detection. Furthermore, since the DC detection circuit 140 can recognize that there is a DC input, rather than an AC input cutoff, it is possible to display that DC is being input. Furthermore, for example, when the image forming apparatus 100 is connected to a power conditioner as a power source, it is also possible to display an abnormality in the power conditioner when DC is being input.

[0105] Although the image forming apparatus 100 described above has been described as an MFP, the image forming apparatus 100 according to the embodiment is not limited to an MFP. For example, the image forming apparatus 100 may be a printer, a facsimile, or a copier. [Explanation of symbols]

[0106] 10 paper feed section, 20 image forming mechanism section, 40 fixing section, 50 discharge section, 63 input power line, 70 commercial power supply, 100 image forming apparatus, 108 current sensor, 110 sub-panel, 111 solar panel, 112 power storage device, 113 control section, 114 display section, 130 power supply board, 140 DC detection circuit, 141 electric wire, 142 limiting resistor, 143 DC detection switch, 144 phototriac, 145 limiting resistor, 146 capacitor, 160 power supply device.

Claims

1. A power supply device that receives an AC input via an input power line and generates a desired voltage, an AC detection unit that detects an AC input to the input power line; a DC detection unit that starts detecting whether or not a DC current is being input from the input power line when the AC detection unit no longer detects an AC current; a control unit that controls the DC detection unit so that a current from the input power line cannot be passed to the DC detection unit when an AC is detected by the AC detection unit, and controls the DC detection unit so that a current from the input power line can be passed to the DC detection unit when an AC is no longer detected by the AC detection unit, The DC detection unit detects that a DC current is being input from the input power supply line when a current flows from the input power supply line. A power supply device comprising:

2. Further comprising a display unit that displays that a direct current is being input when the direct current detection unit detects a direct current.

2. The power supply device according to claim 1 .

3. the DC detection unit includes an electric wire connecting a first position provided on the input power line and a second position provided on the input power line, The electric wire is provided with a switch for connecting or disconnecting the electric wire, The control unit cuts off the electric wire by the switch when an alternating current is detected by the alternating current detection unit, and connects the electric wire by the switch when an alternating current is no longer detected by the alternating current detection unit.

3. The power supply device according to claim 1 or 2.

4. A power generation unit that generates electricity; A storage unit that stores the electricity, The control unit is supplied with electricity from the power storage unit.

4. The power supply device according to claim 1, wherein:

5. Equipped with the power supply device according to any one of claims 1 to 4 An image forming apparatus comprising:

Images