Electric apparatus, image formation device, control method, and program

Abstract

To provide an electric apparatus capable of notifying a user of an abnormality in a protection unit itself for protecting each function unit from overcurrent.SOLUTION: An electric apparatus includes: a functional unit that functions when a voltage is supplied; a power supply unit that supplies the voltage to the functional unit; a protection unit that is switchable between a non-blocking state in which a path for supplying the voltage to the functional unit is not blocked and a blocking state in which the path is blocked in a case where an overcurrent occurs; an execution unit that is capable of executing overcurrent control that causes the overcurrent to occur in the path; a determination unit that detects the voltage in a stage subsequent to the protection unit during a period in which the overcurrent control is executed and determines whether or not there is an abnormality in the protection unit based on detection results; and a notification unit that is capable of executing abnormality notification in a case where it is determined that there is an abnormality in the protection unit.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to an electric device, an image forming apparatus, a control method, and a program. [Background technology]

[0002] Conventionally, in an electrical device having a functional part that functions when a voltage is supplied, there is known a technology that includes a protection part that can be switched between a non-interrupting state that does not interrupt the path for supplying voltage to the functional part, and an interrupting state that interrupts the path when an overcurrent occurs (for example, Patent Document 1). Summary of the Invention [Problem to be solved by the invention]

[0003] However, the above-mentioned conventional technology has a problem in that it is not possible to notify whether or not there is an abnormality in the protection unit itself. In consideration of the above circumstances, an object of the present invention is to make it possible to notify whether or not there is an abnormality in the protection unit. [Means for solving the problem]

[0004] In order to solve the above problem, the electrical device of the present invention comprises a functional unit that functions when voltage is supplied, a power supply unit that supplies voltage to the functional unit, a protection unit that can be switched between a non-blocking state in which the path for supplying voltage to the functional unit is not blocked and a blocking state in which the path is blocked when an overcurrent occurs, an execution unit that can execute overcurrent control to cause an overcurrent in the path, a judgment unit that detects the voltage downstream of the protection unit during the period in which overcurrent control is executed and determines whether or not there is an abnormality in the protection unit based on the detection result, and an alarm unit that can execute an abnormality alarm if it is determined that there is an abnormality in the protection unit. [Effects of the Invention]

[0005] According to the present invention, it is possible to notify whether or not there is an abnormality in the protection unit itself that protects the functional unit from overcurrent. [Brief explanation of the drawings]

[0006] [Figure 1] FIG. 1 is a diagram illustrating the configuration of an MFP, which is an example of an electrical device. [Figure 2] FIG. 2 is a diagram illustrating the hardware configuration of an MFP. [Figure 3] FIG. 2 is a diagram for explaining details of the hardware configuration of an MFP. [Figure 4] FIG. 2 is a functional block diagram of the electrical device. [Figure 5] FIG. 10 is a diagram for explaining a specific example of overcurrent control. [Figure 6] 10 is a flowchart of a process executed by an electrical device. [Figure 7] FIG. 10 is a diagram for explaining a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0007] First Embodiment The present invention will be described in detail below with reference to embodiments shown in the drawings. Figure 1 is a diagram illustrating the schematic configuration of an MFP (Multifunction Peripheral Product Printer) 100, which is an example of an electrical device and an image forming apparatus according to the present invention. However, the present invention may also be applied to electrical devices other than image forming devices.

[0008] The MFP 100 has various functions including, for example, a printer function, a copy function, and a facsimile function. Specifically, the MFP 100 has each functional unit and a power supply device (111 in FIG. 2, described later). When a voltage is supplied from the power supply device to each functional unit, the function of the functional unit can be performed. For example, each of the above functional units includes a printer unit (132 in FIG. 2, described later). When power is supplied to the printer unit, the printer function can be performed.

[0009] Incidentally, when a malfunction occurs in the MFP 100, an overcurrent may occur in each functional unit. If the overcurrent continues to occur, it may cause the functional unit to malfunction. In consideration of the above, a configuration has been proposed in which the MFP 100 is provided with a protection device (112 in FIG. 2, which will be described later). When an overcurrent occurs in the MFP 100, the protection device is controlled to a cut-off state in which the path for supplying voltage to the functional unit is cut off. This prevents the functional unit from malfunctioning due to an overcurrent.

[0010] However, if the protection device itself in MFP100 fails, it is expected that an overcurrent will continue to occur in the functional unit. Taking the above circumstances into consideration, this embodiment is configured to be able to issue an abnormality notification when an abnormality occurs in the protection unit. With the above configuration, it is possible to prevent an overcurrent from continuing to occur in the functional unit. The above configuration will be described in detail later.

[0011] 2 is a diagram illustrating the hardware configuration of the MFP 100 according to this embodiment. As shown in FIG. 2, the MFP 100 includes a controller 101, a short-range communication circuit 120, an engine control unit 130, an operation panel 110, a network I / F 150, a sensor 160, and a locking device 161.

[0012] The controller 101 has a CPU 102, which is the main part of the computer, a memory (MEM-P) 103, a north bridge (NB) 104, a south bridge (SB) 105, an ASIC (Application Specific Integrated Circuit) 106, a local memory (MEM-C) 107, which is a storage unit, an HDD controller 108, and an HD 109, which is also a storage unit, and is configured such that the NB 104 and the ASIC 106 are connected by an AGP (Accelerated Graphics Port) bus 121.

[0013] The CPU 102 is a control unit that performs overall control of the MFP 100. The NB 104 is a bridge that connects the CPU 102 with the memory 103, the SB 105, and the AGP bus 121, and includes a memory controller that controls reading and writing to the memory 103, a PCI (Peripheral Component Interconnect) master, and an AGP target.

[0014] The memory 103 comprises a ROM 103a, which is a memory for storing programs and data that realize the functions of the controller 101, and a RAM 103b, which is used for expanding the programs and data and as a drawing memory during memory printing. The programs stored in the RAM 103b may be provided by being recorded in an installable or executable format on a computer-readable recording medium such as a CD-ROM, CD-R, or DVD.

[0015] The SB 105 is a bridge for connecting the NB 104 with PCI devices and peripheral devices. The ASIC 106 is an integrated circuit (IC) for image processing purposes that has hardware elements for image processing, and serves as a bridge for connecting the AGP bus 121, PCI bus 122, HDD 108, and MEM-C 107.

[0016] The ASIC 106 comprises a PCI target and AGP master, an arbiter (ARB) that forms the core of the ASIC 106, a memory controller that controls the MEM-C 107, a plurality of DMACs (Direct Memory Access Controllers) that perform image data rotation and the like using hardware logic, and a PCI unit that transfers data between the scanner unit 133 and the printer unit 132 via the PCI bus 122. Note that a USB (Universal Serial Bus) interface or an IEEE1394 (Institute of Electrical and Electronics Engineers 1394) interface may be connected to the ASIC 106.

[0017] MEM-C 107 is a local memory used as a copy image buffer and a code buffer. HD 109 is a storage for storing image data, font data used during printing, and forms. HD 109 controls the reading and writing of data from and to HD 109 under the control of CPU 102. AGP bus 121 is a bus interface for a graphics accelerator card proposed to speed up graphics processing, and by directly accessing memory 103 at high throughput, the graphics accelerator card can be made faster.

[0018] The short-distance communication circuit 120 includes a short-distance communication circuit 120a. The short-distance communication circuit 120 is a communication circuit such as NFC, Bluetooth, etc. Furthermore, the engine control unit 130 is made up of a scanner unit 133 and a printer unit 132.

[0019] The operation panel 110 includes a panel display unit 110a such as a touch panel that displays current setting values, selection screens, etc. and accepts input from the operator, and an operation panel 110b that includes a numeric keypad that accepts setting values ​​for image formation conditions such as density setting conditions and a start key that accepts a copy start command. The controller 101 controls the entire MFP 100, and controls, for example, drawing, communication, and input from the operation panel 110. The scanner unit 133 or the printer unit 132 includes an image processing unit that performs error diffusion, gamma conversion, etc.

[0020] MFP 100 can sequentially switch among document box function, copy function, printer function, and facsimile function using the application switching key on operation panel 110. When the document box function is selected, the MFP enters document box mode, when the copy function is selected, the MFP enters copy mode, when the printer function is selected, the MFP enters printer mode, and when the facsimile mode is selected, the MFP enters facsimile mode. Fax unit 114 performs the fax function in facsimile mode.

[0021] The network I / F 150 is an interface for performing data communication using the network N. The short-range communication circuit 120 and the network I / F 150 are electrically connected to the ASIC 106 via a PCI bus 122.

[0022] The power supply device 111 supplies power from an external power source to each functional unit (such as the printer unit 132). The protection device 112 is provided in a path (circuit) from the power supply device 111 to each functional unit, and is controlled to be in either a cutoff state or a non-cutoff state.

[0023] When in the cut-off state, the protection device 112 cuts off the voltage supplied from the power supply device 111 to each functional unit. On the other hand, when in the non-cut-off state, the protection device 112 does not cut off the voltage supplied from the power supply device 111 to each functional unit. Specifically, the protection device 112 detects the current flowing through itself. Furthermore, when a current (overcurrent) greater than a predetermined current (hereinafter sometimes referred to as "reference current Ak") is detected, the protection device 112 is controlled to change from the non-cut-off state to the cut-off state. With the protection device 112 described above, each functional unit is protected from an overcurrent.

[0024] As will be described in detail later, the MFP 100 can transition to a test mode. In the above test mode, it is determined whether or not an abnormality exists in the protection device 112. Specifically, overcurrent control is executed in the test mode. When overcurrent control is executed, a voltage that generates an overcurrent larger than the reference current Ak is supplied to the protection device 112. If the protection device 112 is controlled to an interrupted state in the test mode, it is determined that no abnormality has occurred in the protection device 112. On the other hand, if the protection device 112 is not controlled to an interrupted state despite the execution of overcurrent control, it is determined that an abnormality has occurred in the protection device 112.

[0025] In the above test mode, it is possible to determine whether or not there is an abnormality in the protection device 112. However, if the configuration causes an overcurrent to occur in each functional unit when overcurrent control is executed, the functional unit may fail. Taking the above into consideration, the receiving device 113 is provided in this embodiment. The receiving device 113 is configured to be able to receive the overcurrent generated by the overcurrent control in place of each functional unit. The above configuration will be described in detail below with reference to FIG. 3.

[0026] Fig. 3 is a diagram for explaining in detail the hardware configuration of MFP 100. Fig. 3 shows an excerpt of the components of MFP 100, including controller 101, engine control unit 130, power supply device 111, protection device 112, receiving device 113, and each functional unit (A to D). As shown in Fig. 3, MFP 100 also includes motor MT, solenoid Sol, and clutch CL. Each of the above components operates using voltage from power supply device 111.

[0027] Each functional unit is controlled by the controller 101 or the engine control unit 130. For example, in the specific example of Fig. 3, it is assumed that among the functional units, functional unit A and functional unit B are controlled by control signals from the controller 101. The above-mentioned fax unit 114 and HD 109 are assumed to be functional units A and B.

[0028] 3, it is assumed that among the functional units, functional unit C and functional unit D are controlled by control signals from engine control unit 130. The above-mentioned functional units C and D are assumed to be printer unit 132 and scanner unit 133. In addition, motor MT, solenoid Sol, and clutch CL are controlled by control signals from engine control unit 130.

[0029] A voltage is supplied to each of the above components of the MFP 100 from the power supply device 111. Specifically, the voltage is supplied from the power supply device 111 to each component via the protection device 112. When there is no malfunction in the MFP 100 (in the operating mode described below), a normal current Aa flows through the protection device 112. In FIG. 3, the path through which the normal current Aa flows is indicated by a solid arrow. The normal current Aa is a current smaller than the above-mentioned reference current Ak. On the other hand, when a malfunction occurs in the MFP 100, an overcurrent Ab larger than the reference current Ak may flow through the protection device 112. In the above cases, the protection device 112 transitions from the non-interrupted state to the interrupted state and interrupts the overcurrent Ab.

[0030] As described above, the MFP 100 of this embodiment can transition to a test mode. The above test mode is provided to determine whether or not there is an abnormality in the protection device 112. Specifically, in the test mode, overcurrent control is executed to intentionally generate an overcurrent Ab in the protection device 112. For example, in the overcurrent control, the voltage supplied from the power supply device 111 is changed to a magnitude that generates an overcurrent Ab.

[0031] If no abnormality occurs in the protection device 112, when overcurrent control is executed and an overcurrent Ab occurs, the protection device 112 enters an interrupted state. In the above case, the detection voltage Vk detected at the detection position Pk downstream of the protection device 112 becomes approximately 0 volts. On the other hand, if an abnormality occurs in the protection device 112, even if overcurrent control is executed, the protection device 112 does not enter an interrupted state (does not operate normally). In the above case, the detection voltage Vk detected at the detection position Pk downstream of the protection device 112 becomes greater than approximately 0 volts.

[0032] When overcurrent control is executed in the test mode, the detected voltage Vk is input to the engine control unit 130 as shown in Fig. 3. The engine control unit 130 determines whether the input detected voltage Vk is approximately 0 volts. If the detected voltage Vk is approximately 0 volts, it is determined that no abnormality has occurred in the protection device 112. On the other hand, if the detected voltage Vk is greater than approximately 0 volts, it is determined that an abnormality has occurred in the protection device 112. Note that the detected voltage Vk may be determined in a configuration other than the engine control unit 130 (for example, the controller 101).

[0033] If it is determined that an abnormality has occurred in the protection device 112, a message to notify the fact is displayed on the operation panel 110 (an abnormality notification is executed). According to the above configuration, a user who has confirmed the abnormality notification can eliminate the abnormality in the protection device 112, thereby preventing an overcurrent from continuing to occur in each functional unit.

[0034] However, in test mode (overcurrent control) when an abnormality occurs in the protective device 112, an overcurrent may occur in the downstream (functional unit side) of the protective device 112. In FIG. 3, the path of the overcurrent Ab when an abnormality occurs in the protective device 112 is indicated by a dashed arrow. However, even in test mode, if an overcurrent occurs in the functional unit, it may cause a malfunction of the functional unit. In consideration of the above circumstances, this embodiment employs an accepting device 113 that can accept the overcurrent that has passed through the protective device 112 in test mode instead of the functional unit.

[0035] Specifically, as shown in FIG. 3, the receiving device 113 includes a field effect transistor (FET) 113a and a resistor 113b. The FET 113a is controlled to be in an OFF state or an ON state. When the FET 113a is in an OFF state, the power supply device 111 side and the earth G side are insulated from each other. On the other hand, when the FET 113a is in an ON state, the power supply device 111 side and the earth G side are electrically connected to each other. The FET 113a is normally in an OFF state in an operation mode other than the test mode. On the other hand, when the overcurrent control is being executed in the test mode and an ON signal is input from the signal line S, the FET 113a is turned ON.

[0036] Resistor 113b of receiving device 113 is set to a resistance value that causes overcurrent Ab to flow to the earth G side rather than the functional unit side during the period when power supply device 111 side and earth G side are connected (period when FET 113a is in the ON state). According to the above receiving device 113, even if an abnormality occurs in protection device 112, overcurrent Ab can be released to the receiving device 113 (earth G) side rather than the functional unit side in test mode. Therefore, the inconvenience of overcurrent occurring in the functional unit in test mode is suppressed.

[0037] 4 is a functional block diagram of electrical device (image forming apparatus) 10. For example, CPU 102 in MFP 100 executes a program, causing MFP 100 to function as electrical device 10. As shown in FIG. 4, electrical device 10 includes functional units 11 (a, b, ...), power supply unit 12, protection unit 13, execution unit 14, determination unit 15, acceptance unit 16, notification unit 17, and restriction unit 18.

[0038] As each functional unit 11 (a, b...), for example, each of the functional units (A, B...) (such as the fax unit 114) described above is assumed. The power supply unit 12 supplies voltage to the functional units 11. For example, the power supply device 111 described above functions as the power supply unit 12. The protection unit 13 is switchable between a non-blocking state in which the path for supplying voltage to the functional unit 11 is not blocked, and a blocking state in which the path is blocked when an overcurrent occurs. For example, the protection device 112 described above functions as the protection unit 13.

[0039] The execution unit 14 is capable of executing overcurrent control to generate an overcurrent Ab in a path for supplying voltage. The determination unit 15 detects a voltage (detection voltage Vk) downstream of the protection unit 13 during the period in which the overcurrent control is executed, and determines whether or not an abnormality exists in the protection unit 13 based on the detection result. Specifically, if it is determined that the detection voltage Vk is greater than approximately 0 volts, it is determined that an abnormality has occurred in the protection unit 13.

[0040] The receiving unit 16 can receive current in place of the power function unit 11 during the period when overcurrent control is being performed. For example, the above-described receiving device 113 (a combination of FET 113a and resistor 113b) functions as the receiving unit 16. The notification unit 17 can issue an abnormality notification when it is determined that there is an abnormality in the protection unit 13. For example, the above-described operation panel 110 functions as the notification unit 17. However, the notification unit 17 is not limited to the above examples. For example, the notification unit 17 may be a speaker that outputs a sound to notify of an abnormality in the protection unit 13, or a lamp that notifies of an abnormality in the protection unit 13.

[0041] The restriction unit 18 can restrict the operation of the functional unit 11 when it is determined that there is an abnormality in the protection unit 13. For example, assume that the functional unit 11 includes the above-mentioned printer unit 132. When it is determined that there is an abnormality in the protection unit 13, the restriction unit 18 restricts the printing operation by the printer unit 132.

[0042] 5(a), 5(b-1), and 5(b-2) are diagrams for explaining specific examples of the operation of the electric device 10. When the electric device 10 of this embodiment is powered on, it then transitions to the above-mentioned test mode. Furthermore, if it is determined in the test mode that no abnormality has occurred in the protection unit 13, the electric device 10 ends the test mode and transitions to the operation mode.

[0043] FIG. 5(a) is a diagram illustrating a specific example of the operation of the electrical device 10 in the operating mode. In the operating mode, a voltage is supplied from the power supply unit 12 to each functional unit. In the operating mode, each functional unit generates a current equal to or less than the rated current value corresponding to that functional unit. Also, in the operating mode, as described above, a normal current Aa is generated in the protection unit 13. The normal current Aa is equal to or less than the sum of the rated current values ​​of the functional units. In the operating mode, the receiving unit 16 is in the OFF state. Therefore, the path through which voltage is supplied from the power supply unit 12 to the functional unit 11 is insulated from the earth G.

[0044] 5(b-1) is a diagram illustrating a specific example of the operation of the electrical device 10 in the test mode. When the test mode is started, the receiving unit 16 is controlled to be in the ON state. Therefore, the path through which the voltage is supplied from the power supply unit 12 to the functional unit 11 is electrically connected to the earth G. Furthermore, in the test mode, the above-described overcurrent control is executed, and an overcurrent Ab is generated in the protection unit 13.

[0045] 5(b-1) assumes that the test mode is started when no abnormality occurs in the protection unit 13. In the above case, when the overcurrent control is executed (when the voltage from the power supply unit 12 is increased), the protection unit 13 is controlled to be in a cut-off state, and the front stage (the power supply unit 12 side) and the rear stage (the functional unit 11 and earth G side) of the protection unit 13 are cut off (insulated).

[0046] In the above configuration, in test mode when no abnormality occurs in the protection unit 13, the voltage value in the path downstream of the protection unit 13 (including the detection position Pk) is approximately 0 volts. Therefore, the detected voltage Vk at the detection position Pk is approximately 0 volts. In test mode, the detected voltage Vk is input to the determination unit 15. In the specific example of FIG. 5(b-1), the detected voltage Vk is approximately 0 volts, so the determination unit 15 determines that no abnormality occurs in the protection unit 13.

[0047] Fig. 5(b-2) is a diagram illustrating another specific example of the operation of the electric device 10 in the test mode. The specific example in Fig. 5(b-2) assumes that the test mode is started when an abnormality occurs in the protection unit 13. In the above case, when the overcurrent control is executed, the upstream stage (the power supply unit 12 side) and downstream stage (the functional unit 11 and earth G side) of the protection unit 13 may not be cut off (insulated).

[0048] If the protection unit 13 does not cut off the connection between the power supply unit 12 side and the earth G side, the voltage value of the path downstream of the protection unit 13 (including the detection position Pk) becomes greater than approximately 0 volts. Therefore, the detected voltage Vk at the detection position Pk becomes greater than approximately 0 volts. Therefore, in the specific example of FIG. 5(b-2), the detected voltage Vk becomes greater than approximately 0 volts, and the determination unit 15 determines that an abnormality has occurred in the protection unit 13.

[0049] As described above, in the test mode, the receiving unit 16 is turned on. Therefore, as shown by the dashed arrow in FIG. 5(b-2), the overcurrent Ab that has passed through the protection unit 13 flows into the earth G via the receiving unit 16. Therefore, even if the protection unit 13 does not operate normally in the test mode, the inconvenience of the overcurrent Ab occurring in the functional unit 11 is suppressed.

[0050] If it is determined in the test mode that an abnormality has occurred in the protection unit 13, the operation mode is then changed to the abnormality notification mode. In the abnormality notification mode, an abnormality is notified in the protection unit 13. Furthermore, in the abnormality notification mode, the operation of each functional unit is stopped. When the abnormality in the protection unit 13 is resolved and a predetermined reset operation (such as turning the power back on) is performed, the abnormality notification mode ends and the system transitions to the test mode. However, the system may be configured to be able to transition directly from the abnormality notification mode to the operation mode.

[0051] Fig. 6 is a flowchart of the process executed by the electric device 10. The electric device 10 executes the process shown in Fig. 6, for example, when the power is turned on (when the electric device 10 transitions to the test mode).

[0052] When the power is turned on, the electric device 10 determines whether it is in standby mode (S1). In standby mode, the operation of each of the above-mentioned functional units is restricted. The electric device 10 repeatedly executes step S1 until the standby mode ends (S1: No). If it is determined that the standby mode has ended (S1: Yes), the electric device 10 starts the test mode and executes the above-mentioned overcurrent control (S3). Furthermore, when the test mode starts, the above-mentioned receiving unit 16 is controlled to the ON state, and the subsequent stage of the protection unit 13 is electrically connected to the earth G (see FIG. 5(b-1)).

[0053] After starting the overcurrent control, the electric device 10 determines whether the detected voltage Vk is approximately 0 volts (S3). As described above, when the protection unit 13 operates normally, the upstream stage (the power supply unit 12 side) and downstream stage (the earth G side) of the protection unit 13 are insulated, and the detected voltage Vk at the detection position Pk is approximately 0 volts. If the detected voltage Vk is approximately 0 volts (S3: Yes), the electric device 10 determines that no abnormality has occurred in the protection unit 13 and transitions to the operating mode (S4). After transitioning to the operating mode, the electric device 10 ends the processing shown in FIG. 6.

[0054] On the other hand, if the protection unit 13 does not operate normally, the upstream stage (the power supply unit 12 side) and downstream stage (the earth G side) of the protection unit 13 are not insulated from each other, and the detected voltage Vk at the detection position Pk becomes greater than approximately 0 volts. If the detected voltage Vk is greater than approximately 0 volts (S3: No), the electric device 10 determines that an abnormality has occurred in the protection unit 13 and transitions to the abnormality notification mode (S5). After transitioning to the abnormality notification mode, the electric device 10 ends the processing shown in FIG. 6.

[0055] Second Embodiment Other embodiments of the present invention will be described below. In each of the following exemplary embodiments, elements that have the same actions and functions as those in the first embodiment will be designated by the same reference numerals as those in the first embodiment, and detailed descriptions thereof will be omitted where appropriate.

[0056] 7 is a diagram illustrating a second embodiment. Similar to the electric device 10 of the first embodiment, the electric device 10 of the second embodiment includes a functional unit 11, a power supply unit 12, a protection unit 13, an execution unit 14, a determination unit 15, a notification unit 17, and a restriction unit 18. However, instead of the receiving unit 16 of the first embodiment, the electric device 10 of the second embodiment includes a configuration in which "the execution unit 14 generates an overcurrent Ab during the period in which overcurrent control is performed, but does not allow a current exceeding the rated current to be generated in the electric device 10 of the second embodiment." The receiving unit 16 may also be employed in the second embodiment.

[0057] FIG. 7 shows the current values ​​generated in the operating mode for each component (e.g., functional unit 11). For example, in the operating mode, functional unit A generates a current of approximately 0.5 to 1.5 amperes. Similarly, in the operating mode, functional unit B generates a current of approximately 1 to 2 amperes, functional unit C generates a current of approximately 2 to 3 amperes, functional unit D generates a current of approximately 2 to 3 amperes, motor MT generates a current of approximately 1 to 2 amperes, solenoid Sol generates a current of approximately 1 to 2 amperes, and clutch CL generates a current of approximately 1 to 2 amperes. In the specific example shown in FIG. 7, the normal current Aa generated in protection unit 13 is approximately 8.5 to 15.5 amperes.

[0058] 7 also shows the rated current value of each component (such as functional unit 11). For example, the rated current value of functional unit A is approximately 3 amperes. Similarly, the rated current value of functional unit B is approximately 3 amperes, the rated current value of functional unit C is approximately 4 amperes, the rated current value of functional unit D is approximately 5 amperes, the rated current value of motor MT is approximately 4 amperes, the rated current value of solenoid Sol is approximately 4 amperes, and the rated current value of clutch CL is approximately 3 amperes.

[0059] In the specific example shown in Figure 7, the total rated current value of each component is approximately 26 amperes. For ease of explanation, the current whose value is the total of the rated current values ​​of each component may be referred to as the "upper limit current Ak." If each component is not faulty, the component will not draw a current greater than its rated current value. Therefore, the normal current Aa will be smaller than the upper limit current Ak.

[0060] In the test mode of the second embodiment, the voltage from the power supply unit 12 is changed to be larger than that in the operation mode, as in the test mode of the first embodiment described above. However, in the first embodiment described above, even if the protection unit 13 does not operate normally in the test mode, no current is generated in each functional unit 11, but in the second embodiment, a current can be generated in each functional unit 11.

[0061] For example, in the specific example of Fig. 7, in the test mode, a current of approximately 2.4 amperes flows through functional unit A. Similarly, in the test mode, a current of approximately 2.4 amperes flows through functional unit B, a current of approximately 3.2 amperes flows through functional unit C, a current of approximately 4 amperes flows through functional unit D, a current of approximately 3.2 amperes flows through motor MT, a current of approximately 3.2 amperes flows through solenoid Sol, and a current of approximately 2.4 amperes flows through clutch CL. In the specific example of Fig. 7, the overcurrent Ab generated in protection unit 13 is approximately 20.8 amperes.

[0062] In the second embodiment described above, the overcurrent Ab generated in the test mode is greater than the reference current Ak (as in the first embodiment). Therefore, if the protection unit 13 operates normally, the protection unit 13 is controlled to an off state in the test mode, and the detection voltage Vk becomes approximately 0 volts. On the other hand, if the protection unit 13 does not operate normally, the detection voltage Vk becomes greater than approximately 0 volts. Therefore, as in the first embodiment, it is possible to determine whether or not there is an abnormality in the protection unit 13 based on the detection voltage Vk.

[0063] 7, even if the protection unit 13 does not operate normally in the test mode and a voltage is supplied from the power supply unit 12 to each functional unit 11, a current greater than the rated current value will not be generated in the functional unit 11. According to the second embodiment described above, even if the receiving unit 16 in the first embodiment is omitted, the inconvenience of an overcurrent greater than the rated current value being generated in each functional unit 11 is suppressed.

[0064] Each function executed in the above-described embodiments can be realized by one or more processing circuits. Here, the term "processing circuit" in this specification includes a processor programmed to execute each function by software, such as a CPU implemented by an electronic circuit, as well as devices such as an ASIC (Application Specific Integrated Circuit), a DSP (Digital Signal Processor), an FPGA (Field Programmable Gate Array), and conventional circuit modules designed to execute each of the above-described functions.

[0065] <Summary of the functions and effects of the exemplary embodiment> <First aspect> The electrical device (10) of this aspect includes a functional unit (11) that functions when a voltage is supplied, a power supply unit (12) that supplies voltage to the functional unit, a protection unit (13) that can switch between a non-interrupting state in which the path for supplying voltage to the functional unit is not interrupted and a interrupting state in which the path is interrupted when an overcurrent occurs, an execution unit (14) that can execute overcurrent control to cause an overcurrent to occur in the path, a determination unit (15) that detects a voltage downstream of the protection unit during the period in which the overcurrent control is executed and determines whether or not there is an abnormality in the protection unit based on the detection result, and a notification unit (17) that can issue an abnormality notification when it is determined that there is an abnormality in the protection unit. According to this aspect, it is easy to know that an abnormality has occurred in the protection unit itself.

[0066] <Second mode> The electrical device (10) of this aspect includes a limiting unit (18) that can limit the operation of the functional unit when it is determined that there is an abnormality in the protective unit. According to this aspect, the inconvenience of the functional unit operating in a state in which the protective unit cannot operate normally is suppressed.

[0067] <Third aspect> The electrical device (10) of this aspect includes a receiving section (16) that can receive current in place of the functional section during the period when overcurrent control is being executed. According to this aspect, the inconvenience of overcurrent occurring in the functional section during the period when overcurrent control is being executed is suppressed.

[0068] <Fourth aspect> In the electrical device (10) of this aspect, the execution unit generates an overcurrent in the path during the period when the overcurrent control is being executed, but does not generate a current in the functional unit that exceeds the rated current. According to this aspect, the inconvenience of an overcurrent being generated in the functional unit during the period when the overcurrent control is being executed is suppressed.

[0069] <Fifth aspect> The image forming apparatus (10) of this aspect includes a functional unit (11) that functions when supplied with voltage, a power supply unit (12) that supplies voltage to the functional unit, a protection unit (13) that can switch between a non-interruption state in which the path for supplying voltage to the functional unit is not interrupted and a interruption state in which the path is interrupted when an overcurrent occurs, an execution unit (14) that can execute overcurrent control to cause an overcurrent to occur in the path, a determination unit (15) that detects a voltage downstream of the protection unit during the period in which the overcurrent control is executed and determines whether or not there is an abnormality in the protection unit based on the detection result, and a notification unit (17) that can issue an abnormality notification when it is determined that there is an abnormality in the protection unit. According to this aspect, as in the first aspect, it is easy to know that an abnormality has occurred in the protection unit itself.

[0070] <Sixth aspect> The control method of this aspect is a control method for an electric device including a functional unit (11) that functions when a voltage is supplied to the functional unit, a power supply unit (12) that supplies a voltage to the functional unit, and a protection unit (13) that can switch between a non-interruption state that does not interrupt a path for supplying voltage to the functional unit and a interruption state that interrupts the path when an overcurrent occurs, and includes the steps of: executing overcurrent control to generate an overcurrent in the path (S2 in FIG. 6); detecting a voltage downstream of the protection unit during the period in which the overcurrent control is executed and determining whether or not there is an abnormality in the protection unit based on the detection result (S3 in FIG. 6); and executing an abnormality notification if it is determined that there is an abnormality in the protection unit (S5 in FIG. 6). According to this aspect, the same effects as those of the first aspect can be achieved.

[0071] <Seventh aspect> The program of this aspect causes a computer to execute each step of the sixth aspect. According to this aspect, the same effects as those of the first aspect can be achieved. [Explanation of symbols]

[0072] 10...electrical equipment, 11...functional unit, 12...power supply unit, 13...protection unit, 14...execution unit, 15...judgment unit, 16...reception unit, 17...notification unit, 18...limitation unit. [Prior art documents] [Patent documents]

[0073] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-70110

Claims

1. a functional unit that functions when a voltage is supplied; a power supply unit that supplies a voltage to the functional unit; a protection unit that is switchable between a non-interrupting state in which a path for supplying a voltage to the functional unit is not interrupted and a blocking state in which the path is interrupted when an overcurrent occurs; an execution unit capable of executing overcurrent control to generate an overcurrent in the path; a determination unit that detects a voltage at a stage downstream of the protection unit during a period in which the overcurrent control is being performed, and determines whether or not there is an abnormality in the protection unit based on the result of the detection; a notification unit capable of issuing an abnormality notification when it is determined that an abnormality exists in the protection unit; Electrical equipment equipped with:

2. a limiting unit that can limit the operation of the functional unit when it is determined that there is an abnormality in the protection unit; The electrical device according to claim 1 , comprising:

3. a receiving unit capable of receiving current in place of the functional unit during a period in which the overcurrent control is executed; The electrical device according to claim 1 , comprising:

4. The execution unit generates an overcurrent in the path during a period in which the overcurrent control is executed, but does not generate a current in the function unit that exceeds a rated current. The electrical device according to claim 1 .

5. a functional unit that functions when a voltage is supplied; a power supply unit that supplies a voltage to the functional unit; a protection unit that is switchable between a non-interrupting state in which a path for supplying a voltage to the functional unit is not interrupted and a blocking state in which the path is interrupted when an overcurrent occurs; an execution unit capable of executing overcurrent control to generate an overcurrent in the path; a determination unit that detects a voltage at a stage downstream of the protection unit during a period in which the overcurrent control is being performed, and determines whether or not there is an abnormality in the protection unit based on the result of the detection; a notification unit capable of issuing an abnormality notification when it is determined that an abnormality exists in the protection unit; An image forming apparatus comprising:

6. a functional unit that functions when a voltage is supplied; a power supply unit that supplies a voltage to the functional unit; a protection unit that is switchable between a non-interrupting state in which a path for supplying a voltage to the functional unit is not interrupted and a blocking state in which the path is interrupted when an overcurrent occurs; A method for controlling an electrical device comprising: performing an overcurrent control to generate an overcurrent in the path; detecting a voltage at a stage downstream of the protection unit during a period in which the overcurrent control is being performed, and determining whether or not an abnormality exists in the protection unit based on the result of the detection; a step capable of issuing an abnormality notification when it is determined that an abnormality exists in the protection unit; A control method comprising:

7. A program that causes a computer to execute the steps set forth in claim 6.

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