Image forming apparatus, control method, and program

Abstract

If an abnormality is detected in any of the multiple loads that are currently operating, the system will be able to identify the abnormal load earlier than before. [Solution] The image forming apparatus 1 includes a current detection unit 38 that detects the total current value I supplied from the power supply unit 37 to a plurality of loads 40, a storage unit 33 that stores a current reference value for each of the plurality of loads 40 when each of the plurality of loads 40 is normal for each operating state of the plurality of loads 40, and a control unit 30 that compares the total current value I detected while the plurality of loads 40 are being driven with the current reference value to determine whether there is an abnormality in any of the plurality of loads 40, and stops the operation of the plurality of loads 40 if it is determined that there is an abnormality. When the control unit 30 stops the operation of the plurality of loads 40, it identifies the load with an abnormality by comparing the total current value I with the current reference value corresponding to the operating state while stopping the plurality of loads 40 one by one in sequence.

Description

Technical Field

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

Background Art

[0002] An image forming apparatus such as an MFP (Multifunction Peripheral) has a plurality of loads, such as a motor that drives a conveyance mechanism for conveying sheets, a motor that drives a photoreceptor, a motor that drives a developing device, and a motor that supplies toner. In addition to the motor, the image forming apparatus also has loads such as a fan.

[0003] Conventionally, an image forming apparatus has been proposed that detects a current flowing through a load and compares the detected current value with a reference value to diagnose an abnormality in the load (for example, Patent Documents 1, 2, and 3).

[0004] For example, the image forming apparatus disclosed in Patent Document 1 supplies a control signal to a plurality of controlled objects and detects the amount of current flowing through the controlled objects in response to a change in the control signal. This image forming apparatus determines whether it is normal based on the detected amount of current, and if it is abnormal, cuts off the power supply to the apparatus.

[0005] However, when a plurality of loads are operating simultaneously at the time of detecting the amount of current, the image forming apparatus disclosed in Patent Document 1 cannot identify which load has an abnormality even if it can detect that there is an abnormality based on the detected amount of current among the plurality of loads.

[0006] The image forming apparatus disclosed in Patent Document 2 stores a unit standard value, which is the standard current consumption at a predetermined timing for each of a plurality of functional units. The image forming apparatus acquires the current consumption value at a predetermined timing, compares it with the unit standard value, and determines that an abnormality has occurred if the difference is greater than or equal to the predetermined value. Furthermore, if the image forming apparatus determines that an abnormality has occurred in a certain functional unit, it drives the loads belonging to that functional unit one by one in sequence, compares the current flowing through the loads with the load standard value, and determines whether or not there is an abnormality in the load being driven.

[0007] However, the image forming apparatus described in Patent Document 2, when it determines that there is an abnormality in a functional unit containing multiple loads, stops the functional unit and then drives the multiple loads one by one in sequence. Therefore, this image forming apparatus has the problem that it takes time to identify the abnormal load.

[0008] The image forming apparatus disclosed in Patent Document 3 detects abnormalities by detecting the current flowing through multiple fan motors and comparing the detected current values ​​with a specified value. Therefore, this image forming apparatus can detect if there is an abnormality in any of the multiple fan motors.

[0009] However, the image forming apparatus described in Patent Document 3 cannot identify which of the multiple fan motors is malfunctioning. [Prior art documents] [Patent Documents]

[0010] [Patent Document 1] Japanese Patent Application Publication No. 5-26937 [Patent Document 2] Japanese Patent Publication No. 2006-330506 [Patent Document 3] Japanese Patent Publication No. 2007-233285 [Overview of the project] [Problems that the invention aims to solve]

[0011] This invention was made to solve the above-mentioned problems of the prior art. Specifically, the present invention aims to provide an image forming apparatus, a control method, and a program that can identify a faulty load earlier than in the conventional method when there is a malfunction in any of the multiple loads that are operating. [Means for solving the problem]

[0012] To achieve the above objective, the invention according to claim 1 is an image forming apparatus comprising: a power supply unit that supplies power to a plurality of loads; a current detection unit that detects the total current value supplied from the power supply unit to the plurality of loads; a storage unit that stores a current reference value for each of the plurality of loads when each of the plurality of loads is normal, for each operating state of the plurality of loads; and a control unit that, while driving the plurality of loads, compares the total current value detected by the current detection unit with the current reference value to determine whether there is an abnormality in any of the plurality of loads, and stops the operation of the plurality of loads if it is determined that there is an abnormality, wherein the control unit, when stopping the operation of the plurality of loads, identifies the load with an abnormality by stopping the plurality of loads one by one and comparing the total current value detected by the current detection unit with the current reference value for each operating state of the plurality of loads.

[0013] The invention according to claim 2 is characterized in that, in the image forming apparatus of claim 1, the control unit identifies that there is an abnormality in the stopped load when one of the plurality of loads is stopped and the total current value detected by the current detection unit matches the current reference value for each operating state of the plurality of loads.

[0014] The invention according to claim 3 is an image forming apparatus according to claim 1, characterized in that when the control unit stops one of the plurality of loads and identifies that there is an abnormality in the stopped load, it stops all of the loads that are currently operating among the plurality of loads at once.

[0015] The invention according to claim 4 is an image forming apparatus according to claim 1, wherein the plurality of loads include an operating time setting load with a preset operating time, and when the control unit stops the operation of the plurality of loads, if the operating time setting load is operating among the plurality of loads, the control unit determines the stopping timing of the operating time setting load based on the operating time.

[0016] The invention according to claim 5 is an image forming apparatus according to claim 1, wherein the plurality of loads include a stop-order setting load for which an order in which operation is stopped in the event of an abnormality is predetermined, and the control unit, when stopping the operation of the plurality of loads, determines the stopping timing of the stop-order setting load according to the predetermined order if the stop-order setting load is operating among the plurality of loads.

[0017] The invention according to claim 6 is an image forming apparatus according to claim 5, wherein the stop sequence setting load includes a photoreceptor motor for driving a photoreceptor and a developing motor for driving a developing roller that supplies toner to the photoreceptor, and the sequence is characterized in that the sequence is such that the developing motor is stopped before the photoreceptor motor.

[0018] The invention according to claim 7 is an image forming apparatus according to claim 5, wherein the plurality of loads include an operating time setting load with a preset operating time, and when the control unit stops the operation of the plurality of loads, if the operating time setting load is operating among the plurality of loads, the control unit determines the stopping timing of the operating time setting load based on the operating time, taking precedence over the order of the stop order setting loads.

[0019] The invention according to claim 8 is an image forming apparatus according to claim 4 or 7, wherein the operating time setting load includes a toner supply motor for supplying toner to a developer, and the operating time is the driving time of the toner supply motor for bringing the toner concentration inside the developer to a predetermined concentration.

[0020] The invention according to claim 9 is an image forming apparatus according to claim 1, wherein the plurality of loads includes a conveyance motor for conveying a sheet, and when the control unit stops the operations of the plurality of loads, if the conveyance motor is operating, the conveyance motor is stopped preferentially over other loads.

[0021] The invention according to claim 10 is an image forming apparatus according to claim 1, wherein the plurality of loads includes a fixing motor for driving a fixing roller, and when the control unit stops the operations of the plurality of loads, if the fixing motor is operating, the fixing motor is stopped preferentially over other loads.

[0022] The invention according to claim 11 is an image forming apparatus according to claim 1, further comprising a display unit for displaying various information to a user, and when the control unit identifies a load with an abnormality, the control unit displays on the display unit that there is an abnormality in the identified load.

[0023] The invention according to claim 12 is an image forming apparatus according to claim 1, further comprising a communication unit for communicating with an external device, and when the control unit identifies a load with an abnormality, the control unit notifies the external device via the communication unit that there is an abnormality in the identified load.

[0024] The invention according to claim 13 is a control method for an image forming apparatus, comprising: a power supply unit that supplies power to a plurality of loads; a current detection unit that detects a total current value supplied from the power supply unit to the plurality of loads; and a storage unit that stores a current reference value flowing through the plurality of loads when each of the plurality of loads is normal for each operating state of the plurality of loads. During driving of the plurality of loads, the total current value detected by the current detection unit is compared with the current reference value, and a determination step of determining whether there is an abnormality in any of the plurality of loads is performed. When it is determined that there is an abnormality, a stop step of stopping the operation of the plurality of loads is performed. The stop step is characterized in that when stopping the operation of the plurality of loads, while stopping the plurality of loads one by one, the total current value detected by the current detection unit is compared with the current reference value for each operating state of the plurality of loads, thereby identifying the load with an abnormality.

[0025] The invention according to claim 14 is a program executed in an image forming apparatus, comprising: a power supply unit that supplies power to a plurality of loads; a current detection unit that detects a total current value supplied from the power supply unit to the plurality of loads; and a storage unit that stores a current reference value flowing through the plurality of loads when each of the plurality of loads is normal for each operating state of the plurality of loads. The image forming apparatus is caused to perform a determination step of comparing the total current value detected by the current detection unit with the current reference value during driving of the plurality of loads and determining whether there is an abnormality in any of the plurality of loads, and a stop step of stopping the operation of the plurality of loads when it is determined that there is an abnormality. The stop step is characterized in that when stopping the operation of the plurality of loads, while stopping the plurality of loads one by one, the total current value detected by the current detection unit is compared with the current reference value for each operating state of the plurality of loads, thereby identifying the load with an abnormality.

Effect of the Invention

[0026] According to the present invention, if an abnormality is detected in any of several loads that are in operation, the abnormal load can be identified earlier than in the conventional method. [Brief explanation of the drawing]

[0027] [Figure 1] This figure shows an example of the configuration of an image forming apparatus. [Figure 2] This is a block diagram showing the control mechanism in an image forming apparatus. [Figure 3] This figure shows an example of reference value information. [Figure 4] This figure shows an example of sequential information. [Figure 5] This timing chart shows an example of load shutdown processing when an anomaly is detected while multiple loads are operating. [Figure 6] This flowchart shows an example of a processing procedure performed in the control unit. [Figure 7] This flowchart shows an example of load shutdown processing. [Figure 8] This flowchart shows an example of load shutdown processing. [Figure 9] This figure shows an example of a notification screen displayed on the control panel. [Figure 10] This timing chart shows an example of load shutdown processing when both the load with set operating time and the load with set stop sequence are in operation. [Figure 11] This timing chart shows an example of load shutdown processing when a transport motor is in operation. [Figure 12] This timing chart shows an example of load shutdown processing when the fixing motor is in operation. [Modes for carrying out the invention]

[0028] Preferred embodiments of the present invention will be described in detail below with reference to the drawings. In the embodiments described below, elements common to all are denoted by the same reference numerals, and redundant explanations of these elements will be omitted.

[0029] Figure 1 shows an example of the internal configuration of an image forming apparatus 1, which is one embodiment of the present invention. This image forming apparatus 1 is an MFP that integrates multiple functions, such as a copy function, a print function, and an image reader function. The image forming apparatus 1 has a paper feed transport unit 2 and an image forming unit 3 at the bottom of the main body, and a scanner unit 4 and an automatic document feeder (ADF) 5 at the top of the main body. The image forming apparatus 1 also has an operation panel 6 on the front side of the main body that can be operated by the user.

[0030] The scanner unit 4 and the automatic document feeder 5 operate when scanning documents using the copy function and the image reader function. The scanner unit 4 and the automatic document feeder 5 automatically read the image of the document set by the user and generate image data. The automatic document feeder 5 has a document tray 5a on which documents are placed. When multiple documents are set in the document tray 5a, the automatic document feeder 5 picks up the top document one by one and automatically transports it toward the image reading position of the scanner unit 4. The scanner unit 4 performs image reading in conjunction with the document transport operation of the automatic document feeder 5, and automatically reads the image of the document automatically transported by the automatic document feeder 5 and generates image data.

[0031] The paper feed and transport unit 2 and the image forming unit 3 operate during image formation using the copy and print functions. The paper feed and transport unit 2 feeds and transports sheets 9, such as printing paper, one sheet at a time. The image forming unit 3 forms an image based on the image data to be printed on the sheet 9 transported by the paper feed and transport unit 2.

[0032] The paper feed and transport unit 2 is equipped with multiple paper feed trays 10a, 10b, and 10c, each containing a sheet 9. Each paper feed tray 10a, 10b, and 10c may contain sheets 9 of different types or sizes. The paper feed and transport unit 2 supplies the sheets 9 contained in each paper feed tray 10a, 10b, and 10c one by one toward the downstream transport path 14. For this purpose, the paper feed and transport unit 2 is equipped with a pickup roller 11, a paper feed roller 12, and a sorting roller 13. For example, when feeding a sheet 9 contained in paper feed tray 10a, the paper feed and transport unit 2 rotates the pickup roller 11 and the paper feed roller 12 provided on paper feed tray 10a. As a result, of the multiple sheets 9 contained in paper feed tray 10a, the top sheet 9 is supplied toward the downstream transport path 14.

[0033] The transport path 14 is provided with a registration roller 15, a secondary transfer roller 16, and a fixing unit 8. The registration roller 15 corrects the skew of the sheet 9 fed from the paper feed transport unit 2 and feeds the sheet 9 to the secondary transfer roller 16 at a predetermined timing. The secondary transfer roller 16 forms an image on one surface of the sheet 9 by secondary transfer of the toner image that was primary transferred to the intermediate transfer belt 20 in the image forming unit 3 to one surface of the sheet 9. The sheet 9 on which the toner image has been secondary transferred by the secondary transfer roller 16 then passes through the fixing unit 8 to fix the toner image. The fixing unit 8 includes, for example, a fixing roller including a heating roller 8a and a pressure roller 8b. The fixing unit 8 fixes the toner image to the sheet 9 by sandwiching the sheet 9 between the heating roller 8a and the pressure roller 8b and applying heating and pressure treatment. The heating roller 8a and the pressure roller 8b are rotationally driven by a fixing motor 46 (see Figure 2), which will be described later.

[0034] The fixing section 8 also has a release agent 8c downstream of the nip section formed by the heating roller 8a and the pressure roller 8b. The release agent 8c is a claw-shaped component that peels the sheet 9, which is in close contact with the surface of the heating roller 8a, away from the heating roller 8a and sends it downstream towards the transport path 14.

[0035] Furthermore, the transport path 14 has a reversal path 17 that inverts both the front and back sides of the sheet 9 in order to form an image on the back side of the sheet 9. Downstream of the fuser unit 8, a switching member 18 is provided to switch the transport destination of the sheet 9, which has an image formed on one side. Downstream of the fuser unit 8, the switching member 18 switches the transport path of the sheet 9 to either the output tray 19 or the reversal path 17. For example, if double-sided printing is specified in the print job, the paper feed transport unit 2 drives the switching member 18 so that the transport path of the sheet 9 becomes the reversal path 17. The paper feed transport unit 2 then guides the sheet 9 that has passed through the fuser unit 8 to the reversal path 17 and transports the sheet 9 to the registration roller 15 again with its front and back sides inverted.

[0036] Each roller that transports the sheet 9 along the transport path 14 is rotated by a transport motor 47 (see Figure 2), which will be described later.

[0037] The image forming unit 3 includes an intermediate transfer belt 20 stretched between a drive roller 21 and a driven roller 22. The intermediate transfer belt 20 is configured as an endless belt and circulates between the drive roller 21 and the driven roller 22 as the drive roller 21 rotates. The drive roller 21 is positioned opposite the secondary transfer roller 16. The intermediate transfer belt 20 circulates while being sandwiched between the nip of the drive roller 21 and the secondary transfer roller 16.

[0038] Below the intermediate transfer belt 20, image forming units 23Y, 23M, 23C, and 23K are positioned. These image forming units 23Y, 23M, 23C, and 23K are units that first transfer toner images of Y (yellow), M (magenta), C (cyan), and K (black), respectively, to the intermediate transfer belt 20. For example, the color (Y, M, C) image forming units 23Y, 23M, and 23C are positioned in order upstream of the intermediate transfer belt 20 in the direction of movement. The black (K) image forming unit 23K is positioned at the furthest downstream position in the direction of movement of the intermediate transfer belt 20.

[0039] Each image forming unit 23Y, 23M, 23C, and 23K has a drum-shaped photoreceptor 24 that serves as an image carrier. The photoreceptor 24 is rotated in a predetermined direction (clockwise) by photoreceptor motors 42 and 44 (see Figure 2), which will be described later.

[0040] A cleaning member and a charger are arranged around the photoreceptor 24. Further below the image forming units 23Y, 23M, 23C, and 23K, an exposure unit 25 is provided to expose the photoreceptor 24 of each image forming unit 23Y, 23M, 23C, and 23K. Furthermore, a developer unit 26 is provided around the photoreceptor 24. The developer unit 26 is equipped with a developing roller that supplies a developing material containing toner to the surface of the photoreceptor 24 and is driven by developing motors 43 and 45 (see Figure 2), which will be described later.

[0041] These image forming units 23Y, 23M, 23C, and 23K first charge the surface of the photoreceptor 24 to a predetermined charge using a charger, and then expose it to light using an exposure unit 25, thereby forming an electrostatic latent image on the surface of the photoreceptor 24. Subsequently, the developer unit 26 applies a developer to the surface of the photoreceptor 24, developing the electrostatic latent image with toner. This forms a toner image on the surface of the photoreceptor 24.

[0042] The photoreceptor 24, on which the toner image has been formed, is joined to the intermediate transfer belt 20. Primary transfer rollers 27 are positioned at this joining point, flanking the intermediate transfer belt 20. The primary transfer rollers 27 primary transfer the toner image formed on the photoreceptor 24 to the intermediate transfer belt 20 by the applied transfer voltage. Image forming units 23Y, 23M, 23C, and 23K form a color image on the surface of the intermediate transfer belt 20 by primary transfer, superimposing the toner images of each color onto the intermediate transfer belt 20. The toner image primary transferred to the intermediate transfer belt 20 is secondary transferred to the surface of the sheet 9 supplied by the resist roller 15 as it passes the position of the secondary transfer roller 16.

[0043] Toner bottles 28Y, 28M, 28C, and 28K of the respective colors Y, M, C, and K are provided at the top of the intermediate transfer belt 20. The toner bottles 28Y, 28M, 28C, and 28K contain developer materials containing toner of each color. When the toner density in the developer 26 decreases in each image forming unit 23Y, 23M, 23C, and 23K, the toner bottles 28Y, 28M, 28C, and 28K are driven to rotate, and a toner replenishment operation is performed to supply toner to the developer 26. This toner replenishment operation maintains the toner density in the developer 26 at a predetermined density. When the toner replenishment operation is performed, the toner replenishment motor 41 (see Figure 2), which will be described later, is driven.

[0044] Figure 2 is a block diagram showing the control mechanism in the image forming apparatus 1. The image forming apparatus 1 includes an operation panel 6, a control unit 30, a storage unit 33, a power supply unit 37, a current detection unit 38, a communication unit 39, and a plurality of loads 40.

[0045] The multiple loads 40 include a toner supply motor 41, a color photoreceptor motor 42, a color developer motor 43, a K photoreceptor motor 44, a K developer motor 45, a fuser motor 46, and a transport motor 47. The toner supply motor 41 performs toner supply by rotating the toner bottles 28Y, 28M, 28C, and 28K. The color photoreceptor motor 42 rotates the photoreceptors 24 located in the image forming units 23Y, 23M, and 23C. The color developer motor 43 drives the developer unit 26 located in the image forming units 23Y, 23M, and 23C to supply Y, M, and C toners to the surface of the photoreceptor 24. The K photoreceptor motor 44 rotates the photoreceptor 24 located in the image forming unit 23K. The K developer motor 45 drives the developer unit 26 located in the image forming unit 23K to supply K toner to the surface of the photoreceptor 24. The fixing motor 46 rotates the heating roller 8a and the pressure roller 8b of the fixing unit 8. The conveying motor 47 rotates the various rollers provided in the conveying path 14.

[0046] In reality, the image forming apparatus 1 is equipped with many more loads. However, for the sake of simplicity, this embodiment will explain using an example where the multiple loads 40 include the seven motors shown in Figure 2.

[0047] The power supply unit 37 supplies power to multiple loads 40. The current detection unit 38 detects the total current value I supplied from the power supply unit 37 to the multiple loads 40. The multiple loads 40 are connected in parallel to the power supply unit 37 and the current detection unit 38. When at least one of the multiple loads 40 is operating, the current detection unit 38 detects the total current value I supplied from the power supply unit 37 to the operating load. The current detection unit 38 outputs the detected total current value I to the control unit 30.

[0048] The control unit 30 comprehensively controls the operation of the image forming apparatus 1. The control unit 30 is equipped with a processor such as a CPU (not shown) and reads and executes the program 34 stored in the storage unit 33. In this way, the control unit 30 functions as a job control unit 31 and a load monitoring unit 32. The control unit 30 is connected to each of the multiple loads 40 and controls the operation of each of the multiple loads 40. The control unit 30 is also connected to the operation panel 6, the storage unit 33, and the communication unit 39.

[0049] The storage unit 33 is a non-volatile storage device composed of a hard disk drive (HDD) or a solid-state drive (SSD). The storage unit 33 stores the program 34 executed by the processor of the control unit 30. The storage unit 33 also stores reference value information 35 and sequence information 36.

[0050] The communication unit 39 connects the image forming apparatus 1 to a network such as a LAN (Local Area Network) and communicates via the network. The control unit 30 can communicate with external devices via this communication unit 39.

[0051] The job control unit 31 controls the execution of jobs in the image forming apparatus 1. For example, when the job control unit 31 receives a print job via the communication unit 39, it drives the paper feed transport unit 2 and the image forming unit 3 to control the operation of printing the image onto the sheet 9 and outputting it. At this time, the job control unit 31 controls the operation of each of the multiple loads 40. The job control unit 31 also controls the operation of each of the multiple loads 40 when a copy job is executed in the image forming apparatus 1.

[0052] For example, when forming a color image on sheet 9, the job control unit 31 operates the color photoreceptor motor 42, the color developer motor 43, the K photoreceptor motor 44, the K developer motor 45, the fuser motor 46, and the transport motor 47. Similarly, when forming a monochrome image on sheet 9, the job control unit 31 operates the K photoreceptor motor 44, the K developer motor 45, the fuser motor 46, and the transport motor 47.

[0053] For example, if the toner density in any of the developer units 26 of the image forming units 23Y, 23M, 23C, or 23K decreases during the execution of a print job, the job control unit 31 drives the toner supply motor 41. At this time, the job control unit 31 drives the toner supply motor 41 by specifying the developer unit 26 to which toner is to be supplied. As a result, toner is supplied from the toner bottles 28Y, 28M, 28C, or 28K to the specified developer unit 26, and the toner density in the developer unit 26 is maintained at a predetermined density.

[0054] The load monitoring unit 32 monitors the operating status of multiple loads 40 when they are operating. When at least one of the multiple loads 40 is operating, the load monitoring unit 32 obtains the total current value I detected by the current detection unit 38. Based on the total current value I, the load monitoring unit 32 determines whether or not there is an abnormality in the operating load. At this time, the load monitoring unit 32 reads reference value information 35 from the storage unit 33 and determines whether or not the total current value I is abnormal by referring to the reference value information 35.

[0055] Figure 3 shows an example of reference value information 35. Reference value information 35 is information that records current reference values ​​indicating the range of normal total current values ​​for each operating state of multiple loads 40. The operating state of multiple loads 40 changes depending on the number of operating loads (motors). Therefore, in reference value information 35, current reference values ​​are registered according to the number of operating loads (motors). For example, when all seven motors are operating, the current reference value is registered within the range of current I70 to current I71. When six motors are operating, the current reference value is registered within the range of current I60 to current I61. When five motors are operating, the current reference value is registered within the range of current I50 to current I51. When four motors are operating, the current reference value is registered within the range of current I40 to current I41. When three motors are operating, the current reference value is registered within the range of current I30 to current I31. When both motors are operating, the current reference value is registered within the range of current I20 to current I21. When one motor is operating, the current reference value is registered within the range of current I10 to current I11.

[0056] Furthermore, the current flowing through each of the multiple loads 40 may be different. In that case, the reference value information 35 should be information that registers the current reference value for each combination of loads that are currently operating.

[0057] The load monitoring unit 32 detects the operating status of the loads 40 when multiple loads 40 are operating. Specifically, the load monitoring unit 32 detects the number of loads (motors) that are currently operating among the multiple loads 40. The load monitoring unit 32 then refers to the reference value information 35 and obtains a current reference value corresponding to the detected operating status. When the load monitoring unit 32 obtains the total current value I from the current detection unit 38, it compares the total current value I with the current reference value to determine whether there is an abnormality in any of the multiple loads 40 that are currently operating. Specifically, if the total current value I detected by the current detection unit 38 is within the range of the current reference value, the load monitoring unit 32 determines that there is no abnormality in any of the multiple loads 40 that are currently operating. Conversely, if the total current value I detected by the current detection unit 38 is outside the range of the current reference value, the load monitoring unit 32 determines that there is an abnormality in any of the multiple loads 40 that are currently operating.

[0058] If the load monitoring unit 32 determines that there is an abnormality in any of the multiple loads 40 that are currently operating, it stops the operation of all of the loads 40. If a job is running at this time, the load monitoring unit 32 forcibly interrupts the job execution and stops the operation of all of the loads 40.

[0059] For example, if the total current value I is outside the current reference range when one of the multiple loads 40 is operating, the load monitoring unit 32 can identify that there is an abnormality in the operating load. However, if the total current value I is outside the current reference range when two or more of the multiple loads 40 are operating, the load monitoring unit 32 cannot identify which of the two or more loads is abnormal.

[0060] Therefore, when the load monitoring unit 32 determines that there is an abnormality in any of the multiple loads 40, it performs a process to identify the abnormal load during the load shutdown process, which stops the operation of the multiple loads 40. That is, when the load monitoring unit 32 stops the operation of the multiple loads 40, it stops the multiple loads 40 one by one in sequence. Each time the load is stopped, the load monitoring unit 32 compares the total current value I detected by the current detection unit 38 with the current reference value in its operating state and repeats the process of determining whether or not there is an abnormality. When one load is stopped, if the total current value I is within the range of the current reference value, the load monitoring unit 32 can identify that an abnormality has occurred in the stopped load. Therefore, the load monitoring unit 32 can identify the single load that is experiencing an abnormality during the execution process of the load shutdown process, which stops multiple loads 40.

[0061] The multiple loads 40 include loads with a predetermined stop sequence, which are configured to stop in the event of an abnormality. For example, the color photoreceptor motor 42, the color developer motor 43, the K photoreceptor motor 44, and the K developer motor 45 are loads with a predetermined stop sequence. The stop sequence of these loads is described in the sequence information 36.

[0062] Figure 4 shows an example of sequence information 36. The sequence information 36 contains stop sequences for multiple stop sequence setting loads. In the example in Figure 4, the stop sequence for the color developer motor 43 is set as the first. The stop sequence for the color photoreceptor motor 42 is set as the second. The stop sequence for the K developer motor 45 is set as the third. The stop sequence for the K photoreceptor motor 44 is set as the fourth.

[0063] The reason why the load related to color (Y, M, C) is stopped before the load related to black (K) is due to the arrangement of the image forming units 23Y, 23M, 23C, and 23K. Specifically, the color (Y, M, C) image forming units 23Y, 23M, and 23C are located upstream of the black (K) image forming unit 23K in the direction of movement of the intermediate transfer belt 20. Therefore, by stopping the load driving the color image forming units 23Y, 23M, and 23C first, toner consumption can be reduced.

[0064] Furthermore, the reason for stopping the developing motors 43 and 45 before the photoreceptor motors 42 and 44 is to stop the toner supply to the photoreceptor 24 earlier. By stopping the developing motors 43 and 45 before the photoreceptor motors 42 and 44, toner consumption can be reduced.

[0065] Note that among the multiple loads 40, there are loads for which no stopping order has been set. If a load without a stopping order is operating, the load monitoring unit 32 will basically stop the loads with a set stopping order first, and then stop the loads without a set stopping order in order. However, as will be described later, there are cases in which loads may be stopped with priority over loads with a set stopping order.

[0066] Figure 5 is a timing chart showing an example of load stop processing when an abnormality is detected while multiple loads 40 are operating. Figure 5 shows a state in which multiple loads 40 are operating, including four loads: a color photoreceptor motor 42, a color developer motor 43, a K photoreceptor motor 44, and a K developer motor 45. When multiple loads 40 are operating, the load monitoring unit 32 monitors the operating status of these multiple loads 40 based on the total current value I detected by the current detection unit 38.

[0067] For example, at timing T1, if the load monitoring unit 32 determines that there is an abnormality in any of the multiple loads 40, it prioritizes stopping the four loads with set stopping order one by one in sequence. At this time, the load monitoring unit 32 reads the sequence information 36 and determines the stopping order of the four loads. At timing T2, the load monitoring unit 32 stops the color developing motor 43. After stopping the color developing motor 43, at timing T3, the load monitoring unit 32 obtains the total current value I flowing through the multiple loads 40 that are currently operating and determines whether the total current value I is within the range of the current reference value for the current operating state. If the total current value I is not within the range of the current reference value, there is an abnormal load among the multiple loads 40 that are currently operating.

[0068] Next, at timing T4, the load monitoring unit 32 stops the color photoreceptor motor 42. After stopping the color photoreceptor motor 42, at timing T5, the load monitoring unit 32 obtains the total current value I flowing through the multiple loads 40 currently in operation and determines whether the total current value I is within the range of the current reference value for the current operating state. If the total current value I is not within the range of the current reference value, there is an abnormal load among the multiple loads 40 currently in operation.

[0069] Next, at timing T6, the load monitoring unit 32 stops the K developing motor 45. After stopping the K developing motor 45, at timing T7, the load monitoring unit 32 obtains the total current value I flowing through the multiple loads 40 that are currently operating and determines whether the total current value I is within the range of the current reference value for the current operating state. If the total current value I is not within the range of the current reference value, there is a faulty load among the multiple loads 40 that are currently operating. For example, if only the K photoreceptor motor 44 is operating at timing T7, the load monitoring unit 32 identifies that the K photoreceptor motor 44 is faulty. Then, at timing T8, the load monitoring unit 32 stops the K photoreceptor motor 44.

[0070] Furthermore, if the total current value I is within the range of the current reference value at timing T7, the load monitoring unit 32 identifies that there is an abnormality in the developing motor 45 of K, which was stopped at timing T6. In this case, the load monitoring unit 32 simultaneously stops all currently operating loads at timing T8.

[0071] Figures 6 to 8 are flowcharts illustrating an example of a processing procedure performed in the control unit 30. This processing is primarily performed in the load monitoring unit 32 of the control unit 30. When the control unit 30 starts this processing, it determines whether any of the multiple loads 40 are currently operating (step S10). The control unit 30 then waits until any of the loads become operational (NO in step S10). When the multiple loads 40 start operating in the image forming apparatus 1 (YES in step S10), the control unit 30 detects the operating status of the multiple loads 40 (step S11). At this time, the control unit 30 detects which loads are currently operating from among the multiple loads 40. When a job such as a print job is executed in the image forming apparatus 1, generally, two or more loads included in the multiple loads 40 start operating. Also, during the execution of a job such as a print job, the loads operating among the multiple loads 40 may change sequentially. Therefore, the control unit 30 identifies two or more loads that are currently operating and detects the operating status of the multiple loads 40.

[0072] When the control unit 30 detects the operating state, it obtains the total current value I for the current operating state (step S12). That is, the control unit 30 obtains the total current value I from the current detection unit 38. The control unit 30 reads reference value information 35 from the storage unit 33 and obtains a current reference value corresponding to the current operating state from the reference value information 35 (step S13). Then, the control unit 30 determines whether the total current value I detected by the current detection unit 38 is within the range of the current reference value corresponding to the current operating state (step S14).

[0073] If the total current value I is within the range of the current reference value (YES in step S14), the control unit 30 returns to step S10. The control unit 30 then repeats the processes in steps S10 to S14. In other words, when multiple loads 40 are operating in the image forming apparatus 1, the control unit 30 repeatedly determines whether or not an abnormality has occurred based on the total current value I.

[0074] If the total current value I is not within the range of the current reference value (NO in step S14), the control unit 30 determines that there is an abnormality in one of the multiple loads 40 that are currently operating (step S15). At this time, if two or more loads included in the multiple loads 40 are operating, the control unit 30 cannot determine which of the two or more loads is abnormal. Therefore, if the control unit 30 determines that there is an abnormality in one of the multiple loads 40, it executes a load stop process (step S16). The load stop process (step S16) is a process in which the multiple loads 40 that are currently operating are stopped one by one in order, and the stopped load is determined to be abnormal or not.

[0075] Figure 7 is a flowchart showing an example of load stop processing (step S16). Figure 7 illustrates load stop processing when multiple loads 40 are operating, including four loads: a color photoreceptor motor 42, a color developer motor 43, a K photoreceptor motor 44, and a K developer motor 45, as shown in Figure 5.

[0076] When the control unit 30 starts the load stopping process, it reads sequence information 36 from the storage unit 33 (step S20). Based on the sequence information 36, the control unit 30 determines the stopping order of the currently operating loads. Specifically, the control unit 30 decides to stop the color developer motor 43, the color photoreceptor motor 42, the K developer motor 45, and the K photoreceptor motor 44 one by one in that order.

[0077] The control unit 30 then stops the color developing motor 43 (step S21). When the developing motor 43 is stopped, the control unit 30 obtains the total current value I from the current detection unit 38 (step S22). The control unit 30 also reads out a current reference value corresponding to the current operating state from the reference value information 35 (step S23). The control unit 30 then compares the total current value I with the reference current value and determines whether the total current value I is within the range of the reference current value (step S24).

[0078] If the total current value I is within the range of the reference current value (YES in step S24), the control unit 30 identifies that there is an abnormality in the color developing motor 43 that was stopped in step S21 (step S25). The control unit 30 then proceeds to step S37 in Figure 8.

[0079] If the total current value I is not within the range of the reference current value (NO in step S24), the control unit 30 then stops the color photoreceptor motor 42 (step S26). After stopping the photoreceptor motor 42, the control unit 30 obtains the total current value I from the current detection unit 38 (step S27). The control unit 30 also reads the current reference value corresponding to the current operating state from the reference value information 35 (step S28). The control unit 30 then compares the total current value I with the reference current value and determines whether the total current value I is within the range of the reference current value (step S29).

[0080] If the total current value I is within the range of the reference current value (YES in step S29), the control unit 30 identifies that there is an abnormality in the color photoreceptor motor 42 that was stopped in step S26 (step S30). The control unit 30 then proceeds to step S37 in Figure 8.

[0081] If the total current value I is not within the range of the reference current value (NO in step S29), the control unit 30 proceeds to the flowchart in Figure 8. Next, the control unit 30 stops the developing motor 45 of K (step S31). Once the developing motor 45 is stopped, the control unit 30 obtains the total current value I from the current detection unit 38 (step S32). The control unit 30 also reads the current reference value corresponding to the current operating state from the reference value information 35 (step S33). Then, the control unit 30 compares the total current value I with the reference current value and determines whether the total current value I is within the range of the reference current value (step S34).

[0082] If the total current value I is within the range of the reference current value (YES in step S34), the control unit 30 identifies that there is a problem with the developing motor 45 of K that was stopped in step S31 (step S35). Conversely, if the total current value I is not within the range of the reference current value (NO in step S34), the control unit 30 identifies that there is a problem with the photoreceptor motor 44 of K that is currently in operation (step S36).

[0083] The control unit 30 then notifies the system of the load it has identified as abnormal (step S37). At this time, the control unit 30 displays a notification screen on the display unit of the operation panel 6. This allows the user to identify which of the multiple loads 40 installed in the image forming apparatus 1 has experienced an abnormality. The control unit 30 may also notify an external device of the abnormal load via the communication unit 39. The external device may be, for example, a server device at a service center. By sending a notification to the external device, the external device can arrange for maintenance work on the image forming apparatus 1.

[0084] Subsequently, the control unit 30 stops all currently operating loads at once (step S38). This prevents the load that has experienced an abnormality from continuing to operate.

[0085] Figure 9 shows an example of a notification screen 50 displayed on the display unit 6a of the operation panel 6. When the control unit 30 identifies a load with an abnormality, it displays a notification screen 50 on the display unit 6a as shown in Figure 9. The notification screen 50 shown in Figure 9 shows an example where an abnormality has been detected in the color photoreceptor motor 42. By displaying a notification screen 50 like the one shown in Figure 9 on the operation panel 6, the user can recognize the load that has experienced an abnormality. The user can also recognize that they need to contact the service center.

[0086] Incidentally, among the multiple loads 40 shown in Figure 2, there is an operating time setting load whose operating time is predetermined. For example, the toner supply motor 41 has a predetermined operating time (driving time) in order to maintain the toner concentration in the developer 26 at a predetermined level. If the operating time of the toner supply motor 41 is shorter than the predetermined time, or longer than the predetermined time, it becomes impossible to maintain the toner concentration in the developer 26 at the predetermined level. Therefore, the toner supply motor 41 is one of the operating time setting loads.

[0087] When the control unit 30 determines that the total current value I is not within the range of the current reference value, if an operating time setting load included in the multiple loads 40 is in operation, it determines the stopping timing of the operating time setting load based on a preset operating time. In this case, the control unit 30 determines the stopping timing of the operating time setting load with priority over the stopping order of the stopping order setting loads. Therefore, when multiple stopping order setting loads are in operation, the control unit 30 may interrupt the stopping order of the stopping order setting loads determined based on the order information 36 to stop the operating time setting load.

[0088] Figure 10 is a timing chart showing an example of load stop processing when both the operating time-set load and the stop-order-set load are operating. In the example shown in Figure 10, with the photoreceptor motors 42, 44 and the developer motors 43, 45 operating, the toner supply motor 41, which is the operating time-set load, starts operating at timing T10 and begins supplying toner to the developer 26. For example, when starting the operation of the toner supply motor 41 at timing T10, the control unit 30 sets the operating time Ts of the toner supply motor 41. In the example in Figure 10, the toner supply motor 41 starts operating at timing T10 and continues operating until timing T16. The load monitoring unit 32 of the control unit 30 monitors the operating status of the multiple loads 40 in this state.

[0089] After the toner supply motor 41 starts operating, the control unit 30 determines, for example, at timing T11, that there is an abnormality in one of the loads. In that case, the control unit 30 stops the four loads, which have a set stopping order, one by one, and determines whether there is an abnormality in the stopped load by comparing the total current value I with the current reference value. At this time, when the operating time Ts of the toner supply motor 41 ends, the control unit 30 prioritizes stopping the toner supply motor 41.

[0090] To explain in more detail, at timing T12, the control unit 30 stops the color developing motor 43. After stopping the color developing motor 43, at timing T13, the control unit 30 obtains the total current value I flowing through the multiple loads 40 that are currently operating, and determines whether the total current value I is within the range of the current reference value for the current operating state. If the total current value I is within the range of the current reference value, the control unit 30 determines that the stopped developing motor 43 is an abnormal load. On the other hand, if the total current value I is not within the range of the current reference value, the control unit 30 determines that there is an abnormal load among the multiple loads 40 that are currently operating.

[0091] Next, at timing T14, the control unit 30 stops the color photoreceptor motor 42. After stopping the color photoreceptor motor 42, at timing T15, the control unit 30 obtains the total current value I flowing through the multiple loads 40 that are currently operating, and determines whether the total current value I is within the range of the current reference value for the current operating state. If the total current value I is within the range of the current reference value, the control unit 30 determines that the stopped photoreceptor motor 42 is an abnormal load. On the other hand, if the total current value I is not within the range of the current reference value, the control unit 30 determines that there is an abnormal load among the multiple loads 40 that are currently operating.

[0092] Next, the control unit 30 stops the toner supply motor 41 at timing T16, when the operating time Ts of the toner supply motor 41 ends. In other words, the control unit 30 stops the toner supply motor 41 in priority to the order set in the sequence information 36. This maintains the toner density in the developer unit 26 at a predetermined density. When the toner supply motor 41 is stopped, the control unit 30 obtains the total current value I flowing through the multiple loads 40 currently in operation at timing T17 and determines whether the total current value I is within the range of the current reference value for the current operating state. If the total current value I is within the range of the current reference value, the control unit 30 determines that the stopped toner supply motor 41 is an abnormal load. On the other hand, if the total current value I is not within the range of the current reference value, the control unit 30 determines that there is an abnormal load among the multiple loads 40 currently in operation.

[0093] Next, at timing T18, the control unit 30 stops the K developing motor 45. After stopping the K developing motor 45, at timing T19, the control unit 30 obtains the total current value I flowing through the multiple loads 40 that are currently operating and determines whether the total current value I is within the range of the current reference value for the current operating state. If the total current value I is within the range of the current reference value, the control unit 30 determines that the stopped developing motor 45 is an abnormal load. On the other hand, if the total current value I is not within the range of the current reference value, the control unit 30 determines that there is an abnormal load among the multiple loads 40 that are currently operating. At this time, if only the K photoreceptor motor 44 is operating, the control unit 30 determines that the K photoreceptor motor 44 is an abnormal load. Then, at timing T20, the control unit 30 stops the K photoreceptor motor 44.

[0094] In this manner, if the control unit 30 detects that a load with a set operating time is among the multiple loads 40 that are currently operating, it will sequentially stop the multiple loads 40 one by one while respecting the operating time Ts of the load with the set operating time. Therefore, if there is no abnormality in the load with the set operating time, the operation by the load with the set operating time will terminate appropriately, and no malfunctions will occur.

[0095] Furthermore, when the control unit 30 sequentially stops multiple loads 40 that are in operation, it is preferable to prioritize stopping the transport motor 47 if the sheet 9 is being transported. If the transport motor 47 is forcibly stopped, the transport of the sheet 9 stops in the transport path 14. In a situation where multiple loads 40 are stopping sequentially, if the timing of stopping the transport motor 47 is delayed, the sheet 9 being transported may buckle, potentially causing a bellows jam in the transport path 14. A jammed sheet 9 is difficult to remove from the transport path 14, which reduces work efficiency. Therefore, if the transport motor 47 is included among the multiple loads 40 that are in operation, it is preferable for the control unit 30 to prioritize stopping the transport motor 47 over other loads.

[0096] Figure 11 is a timing chart showing an example of load stop processing when the transport motor 47 is in operation. For example, when the transport motor 47, photoreceptor motors 42, 44, and developer motors 43, 45 are in operation, the load monitoring unit 32 of the control unit 30 monitors the operating status of the multiple loads 40.

[0097] For example, the control unit 30 determines at timing T30 that there is an abnormality in any of the loads. In that case, the control unit 30 determines whether the transport motor 47 is operating, and if the transport motor 47 is operating, it stops the transport motor 47 with priority over other loads. For example, the control unit 30 stops the transport motor 47 at timing T31. This prevents the bellows from jamming due to the sheet 9 being transported.

[0098] When the transport motor 47 is stopped, the control unit 30 obtains the total current value I flowing through the multiple loads 40 currently in operation at timing T32, and determines whether the total current value I is within the range of the current reference value for the current operating state. If the total current value I is within the range of the current reference value, the control unit 30 determines that the stopped transport motor 47 is an abnormal load. On the other hand, if the total current value I is not within the range of the current reference value, the control unit 30 determines that there is an abnormal load among the multiple loads 40 currently in operation.

[0099] Subsequently, the control unit 30 stops each of the photoreceptor motors 42 and 44, and the developer motors 43 and 45 one by one, based on the order set in the sequence information 36, and determines whether or not there is an abnormality. The timings T33 to T39 shown in Figure 11 are the same as the timings T2 to T8 shown in Figure 5. In this way, the control unit 30 can identify the load with an abnormality during the process of stopping the multiple loads 40 one by one in sequence.

[0100] Furthermore, when the control unit 30 sequentially stops multiple loads 40 that are in operation, it is preferable to prioritize stopping the fixing motor 46 if the fixing motor 46 is in operation. In a situation where multiple loads 40 are stopping sequentially, if the stopping timing of the fixing motor 46 is delayed, the leading edge of the sheet 9 may get caught on the release agent 8c or the switching member 18, potentially causing a bellows jam in the fixing unit 8. If a bellows jam occurs in the fixing unit 8, it becomes more difficult to remove than a bellows jam in the transport path 14. Therefore, when the fixing motor 46 is included among the multiple loads 40 that are in operation, it is preferable for the control unit 30 to prioritize stopping the fixing motor 46 over the other loads. For example, if the fixing motor 46 and the transport motor 47 are included among the multiple loads 40 that are in operation, it is preferable for the control unit 30 to stop the fixing motor 46 before the transport motor.

[0101] Figure 12 is a timing chart showing an example of load stop processing when the fuser motor 46 is operating. For example, when the fuser motor 46, transport motor 47, photoreceptor motors 42, 44, and developer motors 43, 45 are operating, the load monitoring unit 32 of the control unit 30 monitors the operating status of the multiple loads 40.

[0102] For example, the control unit 30 determines at timing T40 that there is an abnormality in any of the loads. In that case, the control unit 30 determines whether or not the fuser motor 46 is operating, and if the fuser motor 46 is operating, it stops the fuser motor 46 with priority over other loads. For example, the control unit 30 stops the fuser motor 46 at timing T41. This prevents the control unit 30 from causing a bellows jam inside the fuser unit 8.

[0103] When the fuser motor 46 is stopped, the control unit 30 obtains the total current value I flowing through the multiple loads 40 currently in operation at timing T42, and determines whether the total current value I is within the range of the current reference value for the current operating state. If the total current value I is within the range of the current reference value, the control unit 30 determines that the stopped fuser motor 46 is an abnormal load. On the other hand, if the total current value I is not within the range of the current reference value, the control unit 30 determines that there is an abnormal load among the multiple loads 40 currently in operation.

[0104] Next, the control unit 30 determines whether the transport motor 47 is operating, and if it is operating, it stops the transport motor 47 with priority over other loads. For example, the control unit 30 stops the transport motor 47 at timing T43. This prevents bellows jams from occurring in the transport path 14.

[0105] When the transport motor 47 is stopped, the control unit 30 obtains the total current value I flowing through the multiple loads 40 currently in operation at timing T44, and determines whether the total current value I is within the range of the current reference value for the current operating state. If the total current value I is within the range of the current reference value, the control unit 30 determines that the stopped transport motor 47 is an abnormal load. On the other hand, if the total current value I is not within the range of the current reference value, the control unit 30 determines that there is an abnormal load among the multiple loads 40 currently in operation.

[0106] Subsequently, the control unit 30 stops each of the photoreceptor motors 42 and 44, and the developer motors 43 and 45 one by one, based on the order set in the sequence information 36, and determines whether or not there is an abnormality. The timings T45 to T51 shown in Figure 12 are the same as the timings T2 to T8 shown in Figure 5. In this way, the control unit 30 can identify the load with an abnormality during the process of stopping the multiple loads 40 one by one in sequence.

[0107] As described above, the image forming apparatus 1 of this embodiment executes a job specified by the user by operating a plurality of loads 40. The image forming apparatus 1 includes a current detection unit 38 that detects the total current value I supplied from the power supply unit 37 to the plurality of loads 40 when the plurality of loads 40 are operating. The image forming apparatus 1 also includes a storage unit 33 that stores a reference current value for each of the plurality of loads 40 when each of the plurality of loads 40 is functioning normally. Furthermore, the image forming apparatus 1 includes a control unit 30 that determines whether or not there is an abnormality in any of the plurality of loads 40 while the plurality of loads 40 are being driven.

[0108] The control unit 30 compares the total current value I detected by the current detection unit 38 with a current reference value while driving multiple loads 40 to determine whether there is an abnormality in any of the multiple loads 40. If an abnormality is determined, the control unit 30 executes a load stop process to stop the operation of the multiple loads 40. When stopping the operation of the multiple loads 40 in this load stop process, the control unit 30 stops the multiple loads 40 one by one in sequence and compares the total current value I detected by the current detection unit 38 with the current reference value for each operating state of the multiple loads 40. Through this comparison, the control unit 30 can determine whether there is an abnormality in the stopped load. If there is no abnormality in the stopped load, the abnormal load is still among the multiple loads 40 that are still operating. Therefore, the control unit 30 can identify the abnormal load by repeatedly making a judgment based on the total current value I while stopping the multiple loads 40 one by one in sequence. In other words, the control unit 30 can identify the abnormal load in a series of processes in which it stops the multiple loads 40 after detecting an abnormality in any of the multiple loads 40.

[0109] Therefore, if the image forming apparatus 1 of this embodiment detects an abnormality in any of the multiple loads 40 that are in operation, it is possible to identify the abnormal load at an earlier stage than in the conventional method.

[0110] Furthermore, when the control unit 30 stops one of the multiple loads 40 and identifies that there is an abnormality in the stopped load, it stops all the loads that are currently operating among the multiple loads 40 at once. In other words, once the control unit 30 identifies an abnormal load, it stops all the operating loads at once, rather than stopping the loads one by one sequentially. Therefore, when the image forming apparatus 1 identifies an abnormal load, it can quickly stop all operations.

[0111] Preferred embodiments of the present invention have been described above. However, the present invention is not limited to those described in the above embodiments, and various modifications are applicable.

[0112] For example, in the above embodiment, loads operating during the execution of a print job were illustrated and described. However, the loads mounted on the image forming apparatus 1 include various loads other than those described above. The above-described operation is also applicable when these various loads are operating. Therefore, the loads applicable in the present invention are not limited to those described in the above embodiment.

[0113] Furthermore, in the above embodiment, the image forming apparatus 1 is configured as an MFP, and is an example of a device that integrates multiple functions such as copying, printing, and image reading. However, the image forming apparatus 1 is not limited to being configured as an MFP. For example, the image forming apparatus 1 may be a printer equipped only with a printing function, or a scanner equipped only with an image reading function.

[0114] Furthermore, in the above embodiment, an example was described in which the program 34 executed by the processor of the control unit 30 is pre-stored in the storage unit 33. However, the program 34 can be traded on its own. Therefore, the program 34 may be a program that is installed in the image forming apparatus 1 as needed. In this case, the program 34 may be provided in a form that can be downloaded via a network such as the Internet, or in a form that is recorded on a recording medium such as a CD-ROM or USB memory. [Explanation of symbols]

[0115] 1. Image forming apparatus 6. Control Panel 6a Display section 30 Control Unit 33 Storage section 34 Programs 35 Reference Value Information 36 Order information 37 Power supply section 38 Current detection unit 39 Communications Department 40 Multiple loads 41 Toner supply motor (load) 42 Photoconductor motor (load) 43. Developing motor (load) 44 Photoconductor motor (load) 45 Developing motor (load) 46. ​​Fuser motor (load) 47. Transport motor (load)

Claims

1. A power supply unit that supplies power to multiple loads, A current detection unit that detects the total current value supplied from the power supply unit to the plurality of loads, A storage unit that stores a reference current value for each of the multiple loads when each of the multiple loads is functioning normally, A control unit that, while driving the plurality of loads, compares the total current value detected by the current detection unit with the current reference value, determines whether there is an abnormality in any of the plurality of loads, and stops the operation of the plurality of loads if it determines that there is an abnormality, Equipped with, The image forming apparatus is characterized in that, when the control unit stops the operation of the plurality of loads, it identifies a load with an abnormality by stopping the plurality of loads one by one and comparing the total current value detected by the current detection unit with the current reference value for each operating state of the plurality of loads.

2. The image forming apparatus according to claim 1, characterized in that when the control unit stops one of the plurality of loads, if the total current value detected by the current detection unit matches the current reference value for each operating state of the plurality of loads, the control unit determines that there is an abnormality in the stopped load.

3. The image forming apparatus according to claim 1, characterized in that when the control unit stops one of the loads included in the plurality of loads, it identifies that there is an abnormality in the stopped load, it stops all of the loads that are currently operating among the plurality of loads at once.

4. The aforementioned multiple loads include loads with pre-set operating times, The image forming apparatus according to claim 1, characterized in that when the control unit stops the operation of the plurality of loads, if the load with the operating time setting is in operation among the plurality of loads, the control unit determines the stopping timing of the load with the operating time setting based on the operating time.

5. The aforementioned multiple loads include loads with a predetermined stop order setting that stop operation in the event of an abnormality. The image forming apparatus according to claim 1, characterized in that when the control unit stops the operation of the plurality of loads, if the load for which the stop order is set is in operation among the plurality of loads, the control unit determines the stopping timing of the load for which the stop order is set according to the order.

6. The aforementioned stop sequence setting load is A photoreceptor motor that drives the photoreceptor, A developing motor that drives a developing roller that supplies toner to the photoreceptor, Includes, The image forming apparatus according to claim 5, characterized in that the sequence is such that the developing motor is stopped before the photoreceptor motor.

7. The aforementioned multiple loads include loads with pre-set operating times, The image forming apparatus according to claim 5, characterized in that when the control unit stops the operation of the plurality of loads, if the operation time setting load among the plurality of loads is in operation, it determines the stopping timing of the operation time setting load based on the operation time, taking precedence over the order of the stop order setting loads.

8. The aforementioned operating time setting load is A toner supply motor that replenishes toner to the developing unit. It includes, The image forming apparatus according to claim 4 or 7, characterized in that the operating time is the driving time of the toner supply motor for bringing the toner concentration inside the developer to a predetermined concentration.

9. The aforementioned multiple loads include a transport motor for transporting the sheet. The image forming apparatus according to claim 1, characterized in that when the control unit stops the operation of the plurality of loads, if the transport motor is in operation, it will stop the transport motor preferentially over other loads.

10. The aforementioned multiple loads include a fixing motor that drives the fixing roller, The image forming apparatus according to claim 1, characterized in that when the control unit stops the operation of the plurality of loads, if the fixing motor is in operation, it will stop the fixing motor preferentially over other loads.

11. A display unit that shows various information to the user. Furthermore, The image forming apparatus according to claim 1, characterized in that when the control unit identifies a load with an abnormality, it displays on the display unit that the identified load has an abnormality.

12. A communication unit that communicates with external devices. Furthermore, The image forming apparatus according to claim 1, characterized in that when the control unit identifies a load with an abnormality, it notifies the external device via the communication unit that there is an abnormality in the identified load.

13. A power supply unit that supplies power to multiple loads, A current detection unit that detects the total current value supplied from the power supply unit to the plurality of loads, A storage unit that stores a reference current value for each of the multiple loads when each of the multiple loads is functioning normally, A control method for an image forming apparatus comprising, A determination step in which, while driving the plurality of loads, the total current value detected by the current detection unit is compared with the current reference value to determine whether or not there is an abnormality in any of the plurality of loads, A stopping step that stops the operation of the multiple loads if an abnormality is detected, It has, The control method is characterized in that, when stopping the operation of the plurality of loads, the stopping step involves stopping the plurality of loads one by one, and comparing the total current value detected by the current detection unit with the current reference value for each operating state of the plurality of loads to identify a load with an abnormality.

14. A power supply unit that supplies power to multiple loads, A current detection unit that detects the total current value supplied from the power supply unit to the plurality of loads, A storage unit that stores a reference current value for each of the multiple loads when each of the multiple loads is functioning normally, A program to be executed in an image forming apparatus comprising, A determination step in which, while driving the plurality of loads, the total current value detected by the current detection unit is compared with the current reference value to determine whether or not there is an abnormality in any of the plurality of loads, A stopping step that stops the operation of the multiple loads if an abnormality is detected, Make it run, The program is characterized in that, when stopping the operation of the plurality of loads, it identifies a load with an abnormality by comparing the total current value detected by the current detection unit with the current reference value for each operating state of the plurality of loads while stopping the operation of the plurality of loads one by one.

Images