JP2024047399A - Image forming apparatus, information processing apparatus - Google Patents

Abstract

[Problem] It has not been possible to determine with high accuracy the cause of an abnormality that has occurred in an image forming apparatus. [Solution] The image forming apparatus includes a developer supply container TB used for forming an image on a sheet, an operation state detection unit 208 that detects errors in the operation of the developer supply container TB, a ROM 202 that stores a failure estimation table that indicates the relationship between a failure location that may be the cause of the error and the error occurrence interval, and a CPU 201 that determines the occurrence interval between an error to be analyzed detected by the operation state detection unit 208 and an associated error related to the error to be analyzed, performs a first failure estimation to estimate the failure location of the error to be analyzed based on the occurrence interval determined based on the failure estimation table, and, when there are multiple associated errors, performs a second failure estimation to estimate the failure location of the error to be analyzed by combining the multiple failure locations estimated by the first failure estimation. [Selected Figure] Figure 2

Description

The present invention relates to image forming devices such as copiers, multifunction devices, printers, and facsimiles, and management systems for image forming devices.

When a failure occurs in an image forming device, it is repaired by a customer engineer (hereinafter referred to as "CE") who visits the location where the image forming device is installed. The time it takes to identify the cause of the failure and accurately complete the countermeasure varies depending on the capabilities of the CE. As a result, the time it takes to repair an image forming device varies depending on the CE. In order to shorten the time it takes to repair, a technology has been proposed that estimates the cause of the failure based on in-machine data that indicates the status of the image forming device and notifies the required processing (Patent Document 1). In-machine data is, for example, information that indicates the status inside the device, such as values detected by sensors installed in the image forming device and information on the occurrence of an error.

JP 2017-017611 A

The patent document discloses a fault diagnosis method that uses a diagnostic model generated from the correspondence between a specific fault cause and a sensor that exhibits a characteristic change in output value. This fault diagnosis method searches for a sensor that exhibits a predetermined output value change (data pattern) from the change in the output value of each sensor before a fault occurs, and identifies the cause of the fault that corresponds to that sensor.

However, the fault diagnosis method described in the cited document has a problem in that it is not possible to diagnose the cause of a fault unless the correspondence between the cause of the fault and the sensor is determined in advance. In view of the above problem, the main object of the present invention is to determine with high accuracy the cause of an abnormality that has occurred in an image forming device.

The image forming apparatus of the present invention is characterized by comprising: a component used for forming an image on a sheet; a detection means for detecting an error in the operation of the component; a storage means for storing failure estimation information indicating a relationship between a failure location that may cause the error and an error occurrence interval; and a control means for determining an occurrence interval between an error to be analyzed detected by the detection means and an associated error related to the error to be analyzed, performing a first failure estimation to estimate a failure location of the error to be analyzed based on the occurrence interval determined to be the failure estimation information, and, when there are multiple associated errors, performing a second failure estimation to estimate a failure location of the error to be analyzed by combining the multiple failure locations estimated by the first failure estimation.

The present invention makes it possible to determine with high accuracy the cause of an abnormality occurring in an image forming device.

FIG. 1 is a diagram illustrating the configuration of an image forming apparatus. Controller configuration diagram. FIG. 2 is an overall configuration diagram of a developer supply system. FIG. FIG. FIG. 13A to 13C are diagrams illustrating a state in which the developer supply container cannot be detached. 13A to 13C are diagrams showing a state in which the developer supply container is detachably attached. FIG. 4 is an explanatory diagram of an error code. FIG. 13 is a diagram illustrating an example of error-related information. 4A to 4D are diagrams illustrating failure patterns. FIG. 13 is a diagram illustrating a failure estimation table. 6 is a flowchart showing a process of accumulating error-related information and a process of estimating a failure location. 4 is a flowchart showing a failure pattern determination process. 4A to 4D are diagrams illustrating failure patterns. 4A to 4C are diagrams illustrating failure patterns. 4 is a flowchart showing a process of estimating a failure location. FIG. 1 is a diagram showing the configuration of a fault estimation system. FIG.

The following describes preferred embodiments of the present invention with reference to the accompanying drawings. The present invention will be described in more detail with reference to examples. Although these examples are examples of preferred embodiments of the present invention, the present invention is not limited to the configurations of these examples.

(Configuration of Image Forming Apparatus)
1 is a configuration diagram of an image forming apparatus according to the present embodiment. The image forming apparatus 100 operates by an electrophotographic method and forms a color image on a sheet S. The image forming apparatus 100 employs an intermediate transfer tandem method in which a plurality of image forming units are arranged along a surface onto which an image of an intermediate transfer belt 7 is transferred. The image forming apparatus 100 according to the present embodiment includes four image forming units Pa, Pb, Pc, and Pd in order to form images of four colors, yellow, magenta, cyan, and black. Such an image forming apparatus 100 can be realized by a printer, a copier, a multifunction machine, a facsimile, or the like.

The sheets S are stored in a sheet storage 60 and are fed by a paper feed roller 61 that employs a friction separation method according to the timing of image formation by the image forming units Pa to Pd. The paper feed roller 61 transports the sheets S fed from the sheet storage 60 to the registration roller 62 via a transport path. The registration roller 62 corrects any skew of the sheets S and adjusts the timing to transport the sheets S to the secondary transfer unit T2.

Image forming units Pa to Pd have the same configuration and form images by the same operation, except for the color of the images they form. Image forming units Pa to Pd are equipped with photoconductors 1a to 1d, chargers 2a to 2d, exposure units 3a to 3d, developers 10a to 10d, primary transfer units T1a to T1d, and photoconductor cleaners 6a to 6d. In the following description, when no distinction is made between colors, the suffixes a, b, c, and d will be omitted.

The photoconductor 1 is drum-shaped with a photosensitive layer on its surface, and is rotated around the drum axis. The charger 2 uniformly charges the surface of the rotating photoconductor 1. The exposure unit 3 irradiates the uniformly charged surface of the photoconductors 1a to 1d with light modulated according to the image data of the color to be formed. As a result, an electrostatic latent image according to the image data is formed on the surface of the photoconductor 1.

The developing unit 10 develops the electrostatic latent image formed on the photoreceptor 1 with a developer. In this embodiment, toner is used as the developer. The developing unit 10 forms a toner image on the photoreceptor 1 by attaching toner to the electrostatic latent image on the photoreceptor 1. In the image forming unit Pa, the developing unit 10a contains yellow developer and generates a yellow toner image. In the image forming unit Pb, the developing unit 10b contains magenta developer and generates a magenta toner image. In the image forming unit Pc, the developing unit 10c contains cyan developer and generates a cyan toner image. In the image forming unit Pd, the developing unit 10a contains black developer and generates a black toner image. Note that the number of colors of the toner images formed in the image forming device 100 is not limited to four.

The developing units 10a to 10d in this embodiment contain a two-component developer that is a mixture of non-magnetic toner and magnetic carrier, but may also be a one-component developer that contains only magnetic toner or non-magnetic toner. The developing units 10a to 10d are repeatedly replenished with developer from the developer storage unit when the amount of developer contained therein falls below a predetermined amount due to image formation. When the amount of developer contained therein falls below a predetermined amount, the developer storage unit is repeatedly replenished with developer of the corresponding color from the developer supply containers TBa to TBd, which are developer supply containers. Details of the configuration of the developer supply system consisting of the developer supply container TB, the developer storage unit, and the developing unit 10 will be described later.

The developer replenishment system stabilizes the amount of developer contained in the developing units 10a-10d relative to a predetermined reference amount. By stabilizing the amount of developer contained, the developing units 10a-10d can stabilize the amount of toner that adheres to the photoconductors 1a-1d. This stabilizes the amount of toner in the toner images formed on the photoconductors 1a-1d, and stabilizes the image density.

The primary transfer section T1 transfers the toner images from the photoreceptors 1a to 1d to the intermediate transfer belt 7 by applying a predetermined amount of pressure in the direction of the intermediate transfer belt 7 and an electrostatic load bias. At this time, the toner images formed on the photoreceptors 1a to 1d are superimposed on the intermediate transfer belt 7. The toner remaining on the photoreceptors 1a to 1d after transfer is collected by the photoreceptor cleaners 6a to 6d.

The intermediate transfer belt 7 carries a multi-color toner image by transferring and superimposing the toner images of each color of yellow, magenta, cyan, and black. The intermediate transfer belt 7 is an endless belt that is provided on an intermediate transfer belt frame (not shown) and is stretched by a secondary transfer inner roller 8, a tension roller 17, and a secondary transfer upstream roller 18. The intermediate transfer belt 7 is driven to rotate in the direction of arrow R7 by the secondary transfer inner roller 8, the tension roller 17, and the secondary transfer upstream roller 18. The intermediate transfer belt 7 to which the multi-color toner images have been transferred conveys the multi-color toner images to the secondary transfer section T2 by rotating.

The multi-color toner images formed on the sheet S and the intermediate transfer belt 7 are transported at the same time to the secondary transfer section T2. The secondary transfer section T2 is a transfer nip formed by a secondary transfer inner roller 8 and a secondary transfer outer roller 9 arranged opposite each other. The secondary transfer section T2 is applied with a predetermined pressure force and electrostatic load bias to attract the multi-color toner image from the intermediate transfer belt 7 onto the sheet S. In this way, the secondary transfer section T2 transfers the multi-color toner image on the intermediate transfer belt 7 to the sheet S. Any toner remaining on the intermediate transfer belt 7 after transfer is collected by the transfer cleaner 11.

The sheet S onto which the multi-color toner image has been transferred is transported by the outer secondary transfer roller 9 from the secondary transfer section T2 to the fixing device 13. The fixing device 13 applies a predetermined amount of pressure and heat to the sheet S within the fixing nip formed by the opposing rollers, melting and fixing the multi-color toner image onto the sheet S. When melted and fixed, the multi-color toner image develops color and becomes a full-color toner image. The fixing device 13 is equipped with a heater as a heat source, and is controlled to always maintain an optimal temperature.

The sheet S with the full-color toner image fixed thereon is discharged onto the discharge tray 63. In the case of double-sided printing, the sheet S with an image formed on one side is inverted by the inversion transport mechanism 70 and transported to the registration rollers 62, where an image is formed on the other side. As described above, the image forming device 100 performs image formation processing that forms an image based on image data on a sheet.

(controller)
2 is a diagram showing the configuration of a controller that controls the overall operation of the image forming apparatus 100 configured as described above. This controller 200 shows a configuration for controlling the supply of developer, and configurations for other functions, such as a function for controlling the image forming process, are omitted.

The controller 200 is an information processing device including a CPU (Central Processing Unit) 201, a ROM (Read Only Memory) 202, and a RAM (Random Access Memory) 203. A container drive control unit 206, a container detection unit 209, a remaining amount detection unit 212, an open/close detection unit 215, an internal data storage memory 204, and an operation unit 205 are connected to the CPU 201.

The CPU 201 executes computer programs stored in the ROM 202 to perform various processes by the image forming apparatus 100. In this way, the CPU 201 controls each device of the image forming apparatus 100. For example, the CPU 201 forms a full-color image based on image data on a sheet S. The RAM 203 provides a work area when the CPU 201 performs processing, and stores temporary data, etc. The in-machine data accumulation memory 204 is a storage device that stores (accumulates) in-machine data such as the date and time when an error occurs, a counter value, an error code, etc. The counter value is a value (parameter) that indicates the operating state of the image forming apparatus 100 when an error occurs. The counter value is, for example, the cumulative number of pages printed by the image forming apparatus 100 and the cumulative number of times the developer supply container TB has been replenished.

The operation unit 205 is a user interface that has an input interface and an output interface. The input interface is various key buttons, a touch panel, etc. The output interface is a display, a speaker, etc. The user inputs various instructions and data through the input interface of the operation unit 205. The user can check the status and notifications of the image forming device 100 through the output interface of the operation unit 205.

The container drive control unit 206 controls the container drive unit 207 according to instructions from the CPU 201. The container drive unit 207 includes a drive source for driving the developer supply container TB and opening the container replacement door 213. The container drive unit 207 transmits a drive force exclusively to two different loads, the developer supply container TB and the container replacement door 213, by switching between forward and reverse rotation of one drive source. The container drive unit 207 is driven by a current supplied by the container drive control unit 206 and drives the developer supply container TB. The container drive unit 207 is driven in a direction opposite to that when the developer supply container TB is driven by a current supplied by the container drive control unit 206 in a direction opposite to that when the developer supply container TB is driven, and opens the container replacement door 213. The container replacement door 213 is a door that is opened when the developer supply container TB is replaced, and is provided, for example, on the front of the image forming apparatus 100.

The container detection unit 209 controls the operation state detection unit 208 according to instructions from the CPU 201. The operation state detection unit 208 is an operation monitoring unit that includes a sensor that detects whether the developer supply container TB is operating. The sensor provided in the operation state detection unit 208 is, for example, an optical photosensor. The operation state detection unit 208 detects the operating state of the developer supply container TB and transmits a detection signal representing the operating state to the container detection unit 209. The container detection unit 209 transmits the detection result by the operation state detection unit 208 to the CPU 201.

The CPU 201 obtains the detection result by the operation status detection unit 208 while sending a drive signal to the container drive control unit 206 to drive the container drive unit 207. If the detection result of the operation status detection unit 208 indicates that the developer supply container TB is not driving even though the drive signal is being sent to the container drive control unit 206, the CPU 201 determines that a malfunction has occurred and displays an error on the operation unit 205. At the same time, the CPU 201 accumulates an error code that is pre-assigned according to the type of error, the date and time when the error occurred, and a counter value indicating the operation status of the image forming apparatus 100 as in-machine data in the in-machine data accumulation memory 204.

The remaining amount detection unit 212 controls the remaining amount detection sensor 211 according to instructions from the CPU 201. The remaining amount detection sensor 211 is a sensor that detects the amount of developer in the developer storage unit 210. The remaining amount detection sensor 211 is, for example, a piezoelectric element type powder level sensor equipped with a piezoelectric ceramic and a vibration structure.

The remaining amount detection sensor 211 transmits a detection signal indicating the detection result of the amount of developer in the developer storage section 210 to the remaining amount detection section 212. The remaining amount detection section 212 transmits the detection result by the remaining amount detection sensor 211 to the CPU 201. The CPU 201 acquires the detection result of the remaining amount detection sensor 211 during image formation operation. When the detection result of the remaining amount detection sensor 211 indicates that the amount of developer in the developer storage section 210 is low, the CPU 201 transmits a drive signal to the container drive control section 206 and drives the container drive section 207 to supply developer to the developer storage section 210.

When the developer supply container TB becomes empty, the user or CE replaces the developer supply container TB. At that time, the CPU 201 displays a replacement button on the operation unit 205. When the CPU 201 detects that this replacement button has been pressed, it sends a drive signal to the container drive control unit 206 to rotate the developer supply container TB in the opposite direction to when the container drive unit 207 drives the developer supply container TB. This causes the container drive unit 207 to open the container replacement door 213.

The container replacement door 213 is a door that prevents external access to the developer supply container TB so that replacement work is performed only when the developer supply container TB is empty. The open/closed state of the container replacement door 213 is detected by an open/closed detection sensor 214. The open/closed detection sensor 214 is a status monitoring unit, for example, an optical photosensor. The open/closed detection sensor 214 transmits a detection signal that indicates the detection result of the open/closed state of the container replacement door 213 to the open/closed detection unit 215. The open/closed detection unit 215 transmits the detection result by the open/closed detection sensor 214 to the CPU 201.

When the CPU 201 transmits a drive signal to the container drive control unit 206 to open the container replacement door 213, it acquires the detection result from the open/close detection sensor 214. When the detection result from the open/close detection sensor 214 indicates that the container replacement door 213 has been opened, the CPU 201 stops the drive signal to the container drive control unit 206.

If the detection result of the open/close detection sensor 214 indicates that the container replacement door 213 is not open despite the drive signal being sent to the container drive control unit 206 for a predetermined period of time, the CPU 201 determines that a malfunction has occurred and displays an error on the operation unit 205. At the same time, the CPU 201 stores an error code that is pre-assigned according to the type of error, the date and time when the error occurred, and a counter value indicating the operating status of the image forming apparatus 100 as in-machine data in the in-machine data storage memory 204.

(Developer Supply Operation)
The developer supply system and supply operation will be described with reference to Fig. 3 to Fig. 6. Fig. 3 is a diagram showing the overall configuration of the developer supply system. Fig. 4 is an external view of a developer supply container TB. Figs. 5 and 6 are cross-sectional views of the developer supply system.

As shown in FIG. 3, the developer supply system of this embodiment is mainly composed of a container drive unit 207, a container holding unit 301 that holds the developer supply container TB within the image forming apparatus 100, and a developer storage unit 210. The container drive unit 207 drives the developer supply container TB. The developer storage unit 210 stores a certain amount of developer T and supplies the developer to the developing device 10.

The developer supply container TB is detachable from the image forming device 100. As shown in FIG. 4, the developer supply container TB is composed of a held portion 402 that is held by the container holding portion 301 when attached to the image forming device 100, and a developer storage portion 401 that is rotatable relative to the held portion 402.

As shown in FIG. 5, the container drive unit 207 includes a drive motor 2071 that is driven by a drive signal from the CPU 201, and a drive transmission unit 2072 that transmits the drive force of the drive motor 2071 to the developer supply container TB. The developer storage unit 401 stores developer T for supply inside. The developer storage unit 401 is provided with a drive receiving portion 4012 that receives the drive force from the container drive unit 207 on a part of its outer periphery, and a protrusion 4011. The protrusion 4011 abuts against a detection flag 2082, which will be described later.

The developer storage section 210 is provided to stably supply developer T to the developing device 10, and stores a constant amount of developer T. The developer storage section 210 includes a receiving section 2101, a remaining amount detection sensor 211, a transport section 2102, and a discharge port 2103. The receiving section 2101 is provided at the top of the developer storage section 210, and receives developer T discharged from the developer supply container TB. The remaining amount detection sensor 211 is provided at approximately the center of the developer storage section 210, and detects the remaining amount of developer T inside. The transport section 2102 and the discharge port 2103 are provided below the remaining amount detection sensor 211, and transport developer T to the developing device 10.

A container holder 301 (see FIG. 3) is provided on the upper part of the developer storage section 210. The container holder 301 includes the above-mentioned operating state detection section 208 that monitors the operating state of the developer supply container TB. The operating state detection section 208 includes a photosensor 2081 and a detection flag 2082 that blocks or opens the detection surface of the photosensor 2081 in conjunction with the rotational movement of the developer supply container TB.

When an image formation operation is instructed by a user, the image formation process is executed. As a result, as shown in FIG. 5, the developer T in the developing device 10 is developed onto the photoconductor 1 and consumed. When the CPU 201 determines that a certain amount of developer T in the developing device 10 has been consumed, it supplies developer T from the developer storage section 210 to the developing device 10.

As developer is supplied to the developing device 10, as shown in FIG. 6, the developer T in the developer storage section 210 decreases, and the detection level of the remaining amount detection sensor 211 drops. When the CPU 201 detects from the detection result by the remaining amount detection sensor 211 that the developer T in the developer storage section 210 has decreased below a predetermined amount, it drives the container drive section 207 to supply developer T from the developer supply container TB to the developer storage section 210. In this embodiment, developer T is supplied to the developer storage section 210 by rotating the developer supply container TB in the direction of the arrow m.

The operating state of the developer supply container TB, i.e., whether it is rotating, is monitored by the operating state detection unit 208. Specifically, the CPU 201 monitors whether the photosensor 2081 is blocked or opened by the detection flag 2082 within a certain time after the drive signal of the container drive unit 207 is sent. If the photosensor 2081 is not blocked or opened within the certain time, the CPU 201 determines that there has been some kind of malfunction in the developer supply operation, and stops the supply operation of the developer supply container TB.

Then, the CPU 201 notifies the user that an abnormal condition has occurred and the image forming device 100 has stopped by displaying the message on the operation unit 205. Furthermore, if the image forming device 100 is connected to a network, the CPU 201 notifies the CE or the sales company via the network that an abnormal condition has occurred and the image forming device 100 has stopped. Here, abnormalities in the developer supply operation mainly occur due to two failure conditions.

The first failure state is a state in which the developer supply container TB does not rotate even when it receives a driving force from the container drive unit 207. This type of failure mode is hereinafter referred to as "Failure Mode A". Failure Mode A occurs, for example, as follows. The developer T in the developer supply container TB may be compacted due to vibrations during distribution. This leads to an increase in the rotational load of the developer accommodating portion 401 relative to the held portion 402. The increase in the rotational load of the developer accommodating portion 401 leads to a state of Failure Mode A in which the driving force of the container drive unit 207 cannot rotate the developer accommodating portion 401. Failure Mode A also occurs when the container drive unit 207 simply breaks down and the driving force is not transmitted to the developer supply container TB.

In this case, since the developer supply container TB does not rotate, the detection flag 2082 cannot cover or release the photosensor 2081, and the operating status detection unit 208 detects an abnormality. Furthermore, developer T is not supplied from the developer supply container TB to the developer storage unit 210. Therefore, in the case of failure mode A, the detection level of the remaining amount detection sensor 211 of the developer storage unit 210 does not recover.

The second failure state is a state in which the developer supply container TB receives a driving force from the container drive unit 207 and rotates, but the operation state detection unit 208 cannot detect the operation. This failure mode is hereinafter referred to as "failure mode B". Failure mode B is, for example, a state in which the detection surface of the photosensor 2081 of the operation state detection unit 208 is contaminated by developer. In this case, the photosensor 2081 is not detected as being blocked or released by the detection flag 2082. In addition, in the case of failure mode B, since the developer supply container TB is rotating as described above, a constant amount of developer T is supplied to the developer storage unit 210. In other words, in the case of failure mode B, the detection level of the remaining amount detection sensor 211 of the developer storage unit 210 is restored.

It is desirable for the CE to quickly carry out recovery work for the image forming apparatus 100. For example, in the case of failure mode A, the developer supply container TB or the container drive unit 207 needs to be repaired, and in the case of failure mode B, the operation status detection unit 208 of the container holding unit 301 needs to be repaired. However, in reality, there is a gap of several hours to several days between receiving the notification and carrying out the maintenance work, considering the need to identify the part to be repaired and arrange for the repair parts.

Therefore, the user may be instructed to restart the image forming apparatus 100 by turning the power off and on, and to check whether the image forming apparatus 100 can be restarted and what state it will be in after it is restarted. The first purpose is to collect information to identify the location of the failure by restarting the image forming apparatus 100. The second purpose is that, depending on the nature and type of failure, restarting the image forming apparatus 100 may enable the image forming apparatus 100 to perform image formation to some extent, which may minimize the opportunity loss for the user.

As a specific example, when failure mode A occurs, the CPU 201 stops the image forming device 100 in a state where developer T is not supplied to the developer storage unit 210. When image formation processing begins after a user restarts the device, the CPU 201 detects that the remaining amount of developer T in the developer storage unit 210 is low, and drives the developer supply container TB to supply developer T. As a result, a supply operation abnormality is detected in the same way as before the restart, and the image forming device 100 stops. In this case, the image forming device 100 cannot operate until the CE performs a repair procedure, but the fact that the failure state will soon reoccur is obtained as in-machine data.

On the other hand, if failure mode B has occurred, a certain amount of developer T is supplied to the developer storage section 210. Therefore, the remaining amount detection sensor 211 of the developer storage section 210 may detect that there is a sufficient amount of developer T in the developer storage section 210. In this case, when the image forming process is executed after restarting the image forming apparatus 100, operation can be performed without delay until a certain amount of developer T is consumed. This minimizes the opportunity loss for the user, and in-machine data is obtained that the failure state is not one that will immediately reoccur upon restarting the device.

As described above, when the image forming process is performed, developer T is consumed and developer T is supplied from the developer supply container TB. Here, when the amount of developer T in the developer supply container TB becomes less than a predetermined amount, sufficient developer T is not supplied to the developer storage section 210. If the amount of developer in the developer storage section 210 does not return to normal within a certain time, the CPU 201 determines that the developer T in the developer supply container TB has become empty. Specifically, when the amount of developer in the developer storage section 210 does not return to normal within a certain time, the detection level of the remaining amount detection sensor 211 does not recover even though the developer T supply operation of the developer supply container TB is being performed. After that, the CPU 201 notifies the user or CE by displaying the fact on the operation unit 205. The user or CE replaces the developer supply container TB in response to the notification.

The replacement operation of the developer supply container TB will be described with reference to Figures 7 and 8. Figure 7 is a diagram showing a state in which the developer supply container TB is attached to the image forming apparatus 100 and cannot be removed. Figure 8 is a diagram showing a state in which the developer supply container TB can be removed from the image forming apparatus 100. Note that Figures 7(a) and 8(a) are perspective views. Figures 7(b) and 8(b) are top views. Figures 7(c) and 8(c) are side views. For ease of explanation, the configurations of Figures 7(b), 7(c), 8(b), and 8(c) are simplified.

As shown in FIG. 7A, when the image forming apparatus 100 is in operation, the developer supply container TB is housed in the container housing 700. The developer supply container TB cannot be accessed from the outside by a container replacement door 213 provided on the container housing 700.

As shown in FIG. 7(b), the container replacement door 213 is connected to the drive transmission section 2072 of the container drive section 207 via a link shaft 7001 extending along the container housing 700 and a link member 3011 provided on the container holding section 301. In addition, the container housing 700 is provided with an opening/closing detection sensor 214 that detects the opening and closing of the container replacement door 213.

When the developer supply container TB becomes empty, the user or CE replaces the developer supply container TB. At that time, the developer supply container TB replacement button displayed on the operation unit 205 is pressed, causing the drive motor 2071 and drive transmission unit 2072 of the container drive unit 207 to rotate in the opposite direction to when replenishing the developer T in the developer supply container TB (rotation in the opposite direction to the arrow n in FIG. 6). Note that a clutch (not shown) is provided in part of the drive transmission unit 2072, and the clutch is configured to not transmit the drive force to the developer supply container TB during reverse rotation.

When the drive transmission unit 2072 rotates in the reverse direction, as shown in FIG. 8(b), a part of the drive transmission unit 2072 comes into contact with the link member 3011, causing the link member 3011 to rotate in the direction of arrow P. Next, as the link member 3011 moves, the link shaft 7001 is displaced in the direction of arrow Y. As the link shaft 7001 is displaced, the container replacement door 213 is opened in the direction of arrow S in FIG. 8(c). As shown in FIG. 8(a), when the container replacement door 213 is opened, the user or CE can remove the developer supply container TB in the Y direction and replace it with a new developer supply container.

During the replacement operation of the developer supply container TB, the open/close detection sensor 214 monitors whether the container replacement door 213 is opened correctly. If the open/close detection sensor 214 does not detect the opening or closing of the container replacement door 213 within a predetermined time, the CPU 201 determines that an abnormality has occurred in the replacement operation of the developer supply container TB due to some kind of malfunction, and stops the image forming apparatus 100. The CPU 201 then notifies the user that an abnormal condition has occurred and the image forming apparatus 100 has been stopped by displaying this on the operation unit 205. Also, if the image forming apparatus 100 is connected to a network, the CPU 201 notifies the CE or sales company via the network that an abnormal condition has occurred and the image forming apparatus 100 has been stopped.

Here, abnormalities in the replacement operation of the developer supply container TB mainly occur due to the following three failure conditions.

The third failure state is a failure of the container drive unit 207. This type of failure is hereinafter referred to as "Failure Mode C." Specifically, Failure Mode C occurs when the drive motor 2071 does not operate, or when the drive transmission unit 2072 becomes overloaded and the driving force is not transmitted. In this case, the driving force is not transmitted to the link member 3011 and the link shaft 7001, so the container replacement door 213 does not open.

The fourth failure state is a failure of the link member 3011 or the link shaft 7001 itself that receives the driving force from the container drive unit 207. This type of failure is hereinafter referred to as "Failure Mode D." Specifically, Failure Mode D occurs when the link member 3011 and the link shaft 7001 become disconnected due to improper assembly or shock during logistics. In this case, as with Failure Mode C, the driving force is not transmitted to the link shaft 7001, and the container exchange door 213 does not open.

The fifth failure state is a failure of the open/close detection sensor 214. This type of failure is hereinafter referred to as "failure mode E." In the case of failure mode E, the container replacement door 213 is opened by the driving force of the container drive unit 207, but the open state is not detected.

As described above, it is desirable for the CE to quickly perform recovery work on the stopped image forming apparatus 100. For example, in the case of failure mode C, the container drive unit 207 needs to be repaired, and in the case of failure mode D, the link member 3011 or the link shaft 7001 of the container holding unit 301 needs to be repaired. In the case of failure mode E, the open/close detection sensor 214 needs to be repaired. However, in reality, there is a gap of several hours to several days between receiving the notification and performing the maintenance work, considering the identification of the repair location and the arrangement of the repair parts. Therefore, as described above, the user may be instructed to restart the image forming apparatus 100 by turning it back on, and to check whether the image forming apparatus 100 can be restarted and what state it will be in after it is restarted.

For example, if the replacement operation abnormality is failure mode C or failure mode D, when the image forming apparatus 100 is restarted, a notification urging the user to replace the developer supply container TB is output again. In this case, if the operation unit 205 is operated in the same way as the previous time, there is a high possibility that a similar operation abnormality will occur immediately because the state has not changed. If an operation abnormality occurs, the user or CE is notified of this again. In other words, if an operation abnormality occurs again immediately, the CE can assume that the current operation abnormality is an abnormality in the drive transmission unit 2072, which is the cause of failure mode C, or an abnormality in the link member 3011 or link shaft 7001, which is the cause of failure mode D.

If failure mode E had occurred, the image forming apparatus 100 would have stopped, but since the container replacement door 213 was open, it is possible that the developer supply container TB had been replaced. In this case, when the image forming apparatus 100 is restarted, the CPU 201 detects that the developer supply container TB has been replaced, and no notification is sent to prompt the user to replace it. In other words, if the image forming apparatus 100 is operated normally, it is highly likely that the same operational abnormality will occur again when the replaced developer supply container TB becomes empty. Since the operational abnormality does not occur again immediately, the CE can determine that the cause of the previous operational abnormality is highly likely to be a failure of the open/close detection sensor 214, which is a cause of failure mode E.

(Error code)
Fig. 9 is an explanatory diagram of error codes. Fig. 9 shows the error code displayed on the operation unit 205 when the CPU 201 detects an error, the detected content, the phenomenon that occurs, the failure mode, the failure location, and the operation period until the error occurs again when the operation is restarted. The relationship between each error and the failure content, and the period until the error occurs again when the operation is restarted will be described using Fig. 9.

The error code Err001 is an error that is issued when the operation status detection unit 208 cannot detect the operation of the developer supply container TB even though the container drive unit 207 is being driven. As described above, when the operation status detection unit 208 cannot detect the operation of the developer supply container TB even though the developer supply container TB is being driven, either failure mode A or failure mode B has occurred. In failure mode A, the developer supply container TB or the container drive unit 207 has failed, and in failure mode B, the operation status detection unit 208 has failed. Regardless of which failure mode is the case, the CPU 201 issues the same error code Err001 because it cannot detect the operation of the developer supply container TB.

In failure mode A, the developer supply container TB is not operating, and developer T is not supplied to the developer storage section 210. Therefore, when the image forming apparatus 100 is restarted and operated again after an error occurs, the remaining amount detection sensor 211 detects a decrease in the amount of developer T in the developer storage section 210, and the CPU 201 executes a developer supply operation. Therefore, an error with error code Err001 occurs again after a short operating period, specifically after 10 or fewer printed sheets. The threshold value of 10 printed sheets is the value calculated based on the operating period of the image forming apparatus 100 until an error determination is made, and is the value until an error with error code Err001 reoccurs.

In failure mode B, although the operating state detection unit 208 cannot detect the operating state of the developer supply container TB, the developer supply container TB is operating, and developer is supplied to the developer storage unit 210. Therefore, even if the image forming apparatus 100 is restarted and operated again after the error occurs, the CPU 201 will not execute the developer supply operation until the developer T in the developer storage unit 210 is consumed by the image forming operation and the remaining amount detection sensor 211 detects a decrease in the amount of developer. Therefore, an error with error code Err001 occurs again for a longer operating period than in failure mode A, specifically, when the number of printed sheets is more than 10.

The error code Err002 is issued when the open state of the container replacement door 213 cannot be detected by the open/close detection sensor 214 even though the container drive unit 207 is driven in reverse rotation. As described above, in this case, any of failure modes C, D, and E has occurred. When failure mode C or D has occurred, any of the container drive unit 207, the link member 3011, or the link shaft 7001 has failed. When failure mode E has occurred, the open/close detection sensor 214 has failed. In either case of failure, the CPU 201 cannot detect the open state of the container replacement door 213, and so issues the same error code Err002.

In failure mode C or failure mode D, the container replacement door 213 is not opened, so the developer supply container TB is not replaced and remains empty. Therefore, when the image forming apparatus 100 is restarted and operated again after the error occurs, the CPU 201 drives the container drive unit 207 to open the container replacement door 213 again. However, because the open state of the container replacement door 213 cannot be detected, an error with error code Err002 occurs again. The error with error code Err002 occurs again for a short operating period, specifically, after 10 or fewer printed sheets. The threshold value of 10 printed sheets is the value calculated based on the operating period of the image forming apparatus 100 until the error determination is made, until the error with error code Err002 reoccurs.

In failure mode E, the open/close detection sensor 214 cannot detect the open state, but the container replacement door 213 is open, so the replacement work of the developer supply container TB can be performed. When the developer supply container TB is replaced, the container replacement door 213 is opened again when the replaced developer supply container TB becomes empty. As a result, the error code Err002 reoccurs after a longer operating period than in failure modes C and D, specifically when the number of printed sheets is more than 10.

(Error related information)
10 is a diagram illustrating an example of error-related information stored in the internal data storage memory 204. The error-related information includes the date and time when the error occurred, a counter value indicating the operating state of the image forming apparatus 100, and an error code assigned in advance according to the type of error. In this embodiment, the counter value is the cumulative number of printed sheets by the image forming apparatus 100.

Each time an error is detected, the CPU 201 accumulates the error-related information shown in FIG. 10 in the internal data accumulation memory 204 by adding one line. For example, the error-related information in the first line of FIG. 10 indicates that an error with error code Err001 occurred on 2022/6/1 12:00 in an operating state with a cumulative number of printed sheets of 1,00010. In the fault estimation described below, the CPU 201 refers to this error-related information and estimates the location of the fault from the cumulative number of printed sheets and the error code.

(First Fault Estimation)
In the first failure estimation, failure patterns are classified into a plurality of types (three in this example), and it is determined which failure pattern the error occurrence situation falls into. The failure location is estimated according to the determined failure pattern. FIG. 11 is an explanatory diagram of failure patterns. The horizontal axis of FIG. 11 is the counter value of the image forming apparatus 100. The triangular mark indicates the timing at which the error occurred. The white triangular mark indicates the error that is the subject of analysis for the failure estimation. The black triangular mark indicates an error that occurred earlier than the error that is the subject of analysis.

In fault estimation, one specific error is focused on as the analysis target. Fault estimation is performed using the error code and counter value of the error being analyzed and the error code and counter value of an associated error related to the error being analyzed. An associated error is an error that may occur due to a fault location similar to the fault location where the error being analyzed may occur, and that has occurred earlier than the error being analyzed.

For example, if the error is error code Err001, the fault is in either the developer supply container TB or the container drive unit 207, or the operation status detection unit 208, so an error with error code Err002, in which the container drive unit 207 is the faulty part, may be the related error. Also, if an error with error code Err001 has occurred in the past, that error is defined as the related error.

The fault estimation is performed based on the difference between the counter value when a related error occurred in the past and the counter value when the image forming device 100 is restarted and operated again and the error being analyzed occurs again. This difference in the counter values is called the "operation period." It is determined whether the operation period is within a specified range, and the fault location is estimated based on the result of this determination.

Figure 11 (a) shows a failure state in which the operating period between the error being analyzed and the related error is short, and an error occurs immediately after restarting operation. Because errors occur successively, this type of failure pattern is defined as "continuous." CPU 201 determines whether related errors have occurred within threshold A of the operating period, and if related errors have occurred within threshold A, determines that the failure pattern is continuous. Threshold A is a value that is set in advance to determine that the failure pattern is continuous, and is stored in ROM 202. Threshold A may be determined by calculating a value with a high statistical probability based on data that associates a large number of error occurrence information with failure locations.

Figure 11 (b) shows a failure state in which the operating period between the error being analyzed and the associated error is longer than that of a continuous failure pattern. Since the error interval is long, this type of failure pattern is defined as "intermittent". CPU 201 determines whether the associated error is greater than threshold A and within the range of threshold B. If the associated error is greater than threshold A and within the range of threshold B, CPU 201 determines that the failure pattern is intermittent. Threshold B is a value that is set in advance to determine that the failure pattern is intermittent and is stored in ROM 202. Threshold B is a period longer than threshold A. Threshold B may be determined by calculating a value with a high statistical probability based on data that associates a large number of error occurrence information with failure locations.

Figure 11 (c) shows a state in which the operating period between the error being analyzed and the related error is even longer than in the case of an intermittent failure pattern. In such a case, since the period of stable operation is long, it is determined that the possibility of the specified failure state continuing indefinitely is low. Therefore, it is determined that the error being analyzed and the related error are not caused by the same failure factor, but are each caused by independent failure factors.

That is, the CPU 201 determines that there are no associated errors that have occurred due to the same failure cause as the error being analyzed. Since no associated errors have occurred, this failure pattern is defined as "not occurring." In this case, since there is no information to perform failure inference, it is not possible to perform failure inference based on the counter value. The CPU 201 determines that there are no associated errors within the range of threshold A, and that there are no associated errors within the range of threshold B that is greater than threshold A, and determines that the failure pattern is not occurring.

Figure 11(d) shows a state where no associated error has occurred. In such a case, since there is no information to perform fault estimation, fault estimation based on the counter value cannot be performed. This type of fault pattern is defined as not occurring, just like in Figure 11(c). The processing of the CPU 201 is the same as in Figure 11(c). The CPU 201 determines that there is no associated error within the range of threshold A, and that there is no associated error within the range of threshold B that is greater than threshold A, and determines that the fault pattern has not occurred.

Figure 12 is an example diagram of a fault estimation table. The fault estimation table in Figure 12 is fault estimation information that compiles, for each combination of the error code of the error to be analyzed and the related error, information indicating the relationship between the judgment conditions based on threshold A and threshold B, the fault pattern, and the fault location that may be the cause of the error. The CPU 201 performs fault estimation based on the fault estimation table. The fault estimation table is stored in the ROM 202, and is read out when fault estimation is performed. Details of the fault estimation table will be described.

No. 1 is a case where the error code to be analyzed is "Err001", the related error code is "Err001", and the failure pattern is continuous. This corresponds to failure mode A in FIG. 9. Threshold A for determining whether it is continuous or intermittent is 10 sheets. The CPU 201 determines that it corresponds to No. 1 when an error with related error code Err001 occurs within a range of 10 sheets or less, based on the time when an error with error code Err001 to be analyzed occurs. In this case, the CPU 201 estimates that the failure location is either the developer supply container TB or the container drive unit 207.

No. 2 is a case where the error code to be analyzed is "Err001", the related error code is "Err001", and the failure pattern is intermittent. This corresponds to failure mode B in FIG. 9. Threshold B for determining whether it is intermittent or not occurring is 1000 sheets. The CPU 201 determines that it corresponds to No. 2 when an error with related error code Err001 has occurred within a range of more than 10 sheets and not more than 1000 sheets, based on the time when an error with error code Err001 to be analyzed has occurred. In this case, the CPU 201 estimates that the location of the failure is the operation status detection unit 208.

No. 3 is a case where the error code to be analyzed is "Err001", the related error code is "Err001", and no failure pattern occurs. The CPU 201 determines that the case corresponds to No. 3 when the error of the related error code Err001 has not occurred within a range of 1000 sheets or less from the time when the error of the error code Err001 to be analyzed occurred. In this case, since the CPU 201 does not have information to estimate the failure, it estimates that the failure location is one of all the locations related to the error code Err001 to be analyzed. One of all the locations related to the error code Err001 is one of the developer supply container TB, the container drive unit 207, and the operation status detection unit 208.

No. 4 is a case where the error code to be analyzed is "Err002", the related error code is "Err001", and the failure pattern is continuous. When both the error code Err002 and the error code Err001 occur, the only failure location that can be a common cause of the failure is the container drive unit 207, as shown in FIG. 9. Therefore, the CPU 201 estimates that the failure location is the container drive unit 207 regardless of the counter value. The threshold A for determining whether the failure is continuous or intermittent is 10 sheets. The CPU 201 determines that the case corresponds to No. 4 when the error code Err002 to be analyzed occurs within a range of 10 sheets or less. In this case, the CPU 201 estimates that the failure location is the container drive unit 207.

Case No. 5 is a case where the error code being analyzed is "Err002", the related error code is "Err001", and the failure pattern is intermittent. Like case No. 4, both the error code Err002 and the error code Err001 have occurred, and the location of the failure and the processing of the CPU 201 are the same as in case No. 4. Cases No. 4 and No. 5 may be combined into a single case with the judgment condition set to 1000 sheets or less.

The following is an example of an error with error code Err001 occurring in the past, followed by an error with error code Err002. For example, after an error with error code Err001 occurs due to a malfunction of the container drive unit 207, the CE operates the operation unit 205 to check the condition of the developer supply container TB, and forcibly opens the container replacement door 213. Even if an attempt is made to open the container replacement door 213, an error with error code Err002 occurs because the container drive unit 207 is malfunctioning.

No. 6 is a case where the error code to be analyzed is "Err002", the related error code is "Err001", and no failure pattern occurs. The CPU 201 determines that No. 6 applies if the error of the related error code Err001 has not occurred within a range of 1000 sheets or less from the time when the error of the error code Err002 to be analyzed occurred. In this case, since the CPU 201 does not have information to estimate the failure, it estimates that the failure location is one of all the locations related to the error code Err002 to be analyzed. The one of all the locations related to the error code Err002 to be analyzed is one of the container drive unit 207, the link member 3011, the link shaft 7001, and the open/close detection sensor 214.

No. 7 is a case where the error code to be analyzed is "Err002", the related error code is "Err002", and the failure pattern is continuous. This corresponds to failure modes C and D in FIG. 9. The threshold A for determining whether the error is continuous or intermittent is 10 sheets. The CPU 201 determines that the case corresponds to No. 7 when the error of the related error code Err002 occurs within a range of 10 sheets or less based on the time when the error of the error code Err002 to be analyzed occurs. In this case, the CPU 201 estimates that the failure location is either the container drive unit 207, the link member 3011, or the link shaft 7001.

No. 8 is a case where the error code to be analyzed is "Err002", the related error code is "Err002", and the failure pattern is intermittent. This corresponds to failure mode E in FIG. 9. Threshold B for determining whether the error is intermittent or not occurring is 1000 sheets. The CPU 201 determines that the case corresponds to No. 8 when the error with the related error code Err002 has occurred within a range of more than 10 sheets and less than or equal to 1000 sheets, based on the time when the error with the error code Err002 to be analyzed has occurred. In this case, the CPU 201 estimates that the failure location is the open/close detection sensor 214.

No. 9 is a case where the error code to be analyzed is "Err002", the related error code is "Err002", and no failure pattern occurs. The CPU 201 determines that No. 9 applies if the error of the related error code Err002 has not occurred within a range of 1000 sheets or less from the time when the error of the error code Err002 to be analyzed occurred. In this case, since the CPU 201 does not have information to estimate the failure, it estimates that the failure location is one of all the locations related to the error Err002 to be analyzed. The one of all the locations related to the error Err002 to be analyzed is one of the container drive unit 207, the link member 3011, the link shaft 7001, and the open/close detection sensor 214.

Figure 13 is a flowchart showing the process of accumulating error-related information and estimating the location of a fault. This series of processes is executed when an error occurs in the image forming device 100.

The CPU 201 acquires information related to errors that have occurred in the past from the on-board data storage memory 204 (S101). The CPU 201 accumulates information related to newly occurring errors in the on-board data storage memory 204 (S102). The CPU 201 acquires a failure estimation table from the ROM 202 (S103).

The CPU 201 determines the failure pattern of the associated error based on the past error-related information (S104). This determination is performed for each associated error. For example, if the error code to be analyzed is "Err002", the CPU 201 determines based on the failure estimation table that there are two associated error codes corresponding to "Err002", "Err001" and "Err002", and determines the failure pattern. The method of determining the failure pattern will be described in detail later.

The CPU 201 estimates the location of the failure from the error code and the failure pattern based on the failure estimation table (S105). For example, if the error code to be analyzed is "Err001", the related error code is "Err001", and the failure pattern is continuous, the CPU 201 estimates that the location of the failure is either the developer supply container TB or the container drive unit 207. If multiple types of related errors occur and correspond to multiple failure patterns, the CPU 201 combines the failure locations estimated for each failure pattern to obtain the estimation result. For example, assume that the error code to be analyzed is "Err002", the related error code is "Err001", the failure pattern is continuous, and the related error code is "Err002", the failure pattern is intermittent, and both are obtained. In this case, the CPU 201 estimates that the location of the failure is either the container drive unit 207 or the open/close detection sensor 214, which are the respective failure locations.

Based on the result of the fault estimation process, the CPU 201 displays information on the fault location on the operation unit 205 (S106). With this, the CPU 201 ends the series of processes. Note that the display on the operation unit 205 may display not only the fault location but also maintenance-related information. The maintenance-related information may be, for example, a part replacement procedure or an estimated work time required for maintenance. The maintenance-related information corresponding to the fault location is, for example, stored in advance in the ROM 202. After estimating the fault, the CPU 201 reads out the corresponding maintenance-related information from the ROM 202 and displays it on the operation unit 205. In addition, if the image forming apparatus 100 is connected to a network, the CPU 201 notifies the CE of the fault location and the maintenance-related information via the network.

FIG. 14 is a flowchart showing the failure pattern determination process in S104.
The CPU 201 calculates the difference in counter value between the error to be analyzed and the associated error, and determines whether the calculated difference is within threshold value A (S201). As described above, threshold value A is 10 printed sheets in this embodiment. For example, if the cumulative number of printed sheets for the error to be analyzed is 100,000 sheets and the cumulative number of printed sheets for the associated error is 99,999 sheets, the difference is 1 sheet. The CPU 201 determines whether this difference is within threshold value A, which is 10 sheets.

If the difference is within threshold A (S201: Y), the CPU 201 determines that the failure pattern is continuous (S202) and ends the failure pattern determination process. If the difference is greater than threshold A (S201: N), the CPU 201 determines whether the difference calculated in the process of S201 is greater than threshold A and within threshold B (S203). As described above, threshold B is 1000 printed sheets in this embodiment. If the difference is within threshold B (S203: Y), the CPU 201 determines that the failure pattern is intermittent (S204) and ends the failure pattern determination process. If the difference is greater than threshold B (S203: N), the CPU 201 determines that the failure pattern has not occurred (S205) and ends the failure pattern determination process.
In the first fault estimation described above, the fault location is estimated based on the occurrence timing of an associated error with respect to the error to be analyzed.

(Second Fault Estimation)
The second fault estimation is a fault estimation in the case where a plurality of fault patterns occur due to a plurality of related errors for the error to be analyzed. FIGS. 15 and 16 are explanatory diagrams of fault patterns. The horizontal axis in FIGS. 15 and 16 is the counter value of the image forming apparatus 100, as in FIG. 11. The triangular mark indicates the timing at which the error occurred. The white triangular mark indicates the error to be analyzed for the fault estimation. The black triangular mark indicates an error that occurred earlier than the error to be analyzed. FIG. 17 is a flowchart showing the fault location estimation process of S105 in FIG. 13. Here, the error to be analyzed is the error with error code Err002 (see FIG. 9), the first related error among the multiple related errors is the error with error code Err001, and the second related error among the multiple related errors is the error with error code Err002.

The failure pattern shown in FIG. 15(a) represents a failure state in which the operating period between the analysis target error and the first and second related errors is short, and an error occurs immediately after restarting operation. In this case, the CPU 201 performs the processes of S101 to S105 in the flowchart of FIG. 13, and estimates the failure location based on failure patterns No. 4 and No. 7 in the failure estimation table of FIG. 12. Specifically, No. 4 is a case in which the error code of the analysis target error is Err002, the error code of the related error is Err001, and the failure pattern is continuous. In this case, the CPU 201 estimates the failure location to be the container drive unit 207. No. 7 is a case in which the error code of the analysis target error is Err002, the error code of the related error is Err002, and the failure pattern is continuous. In this case, the CPU 201 estimates the failure location to be one of the container drive unit 207, the link member 3011, and the link shaft 7001.

The container drive unit 207 is estimated as the faulty part in both failure patterns No. 4 and No. 7. If the link member 3011 or the link shaft 7001 were the faulty part, then since the failure pattern No. 4 has occurred, it is estimated that the container drive unit 207 has also failed. In other words, it is estimated that multiple failures, such as a failure of the container drive unit 207 and a failure of the link member 3011, or a failure of the container drive unit 207 and a failure of the link shaft 7001, have occurred close to the time when the error to be analyzed occurred. Such simultaneous occurrence of two failures is hereinafter referred to as a "double failure." Here, from experience, the possibility of a double failure occurring is quite low. Therefore, in such a case, it is considered that the faulty part is highly likely to be the container drive unit 207, which is estimated as the faulty part in both failure patterns No. 4 and No. 7.

When multiple failure patterns occur, the CPU 201 performs the failure location estimation process of S105 in FIG. 13 as shown in FIG. 17. The CPU 201 estimates the failure location from the failure pattern using the first failure estimation based on the failure table in FIG. 12 (S105a). When multiple failure patterns occur, the CPU 201 performs the first failure estimation for each failure pattern and estimates the failure location of each failure pattern. Next, the CPU 201 estimates the failure location of the analysis target error by combining the estimation results of the failure location from the multiple failure patterns using the second failure estimation (S105b).

In the case of the failure pattern in FIG. 15(a), the CPU 201 combines the container drive unit 207 estimated from the failure pattern No. 4 with the container drive unit 207, link member 3011, and link shaft 7001 estimated from the failure pattern No. 7. As a result, the CPU 201 estimates that the container drive unit 207, which has the highest estimation frequency, is the failed part. Therefore, the CPU 201 can notify the user or CE that the failure will be resolved by repairing and treating the container drive unit 207 during maintenance, and can provide information useful for preparing replacement parts and shortening work time during maintenance.

The failure pattern shown in FIG. 15(b) represents a failure state in which the operating period between the analysis target error and the first related error is short, and the operating period between the analysis target error and the second related error is long. In other words, FIG. 15(b) is a case in which failure patterns No. 4 and No. 8 in FIG. 12 have occurred. Therefore, the CPU 201 estimates the failure location based on failure patterns No. 4 and No. 8 using the process in FIG. 13 and the failure estimation table shown in FIG. 12. In the case of failure pattern No. 4, the CPU 201 estimates the failure location to be the container drive unit 207. Similarly, in the case of failure pattern No. 8, the CPU 201 estimates the failure location to be the open/close detection sensor 214.

Furthermore, as before, the CPU 201 performs the process of S105b in FIG. 17, which is the second fault estimation. In this case, the estimation frequency of the container driving unit 207 and the open/close detection sensor 214 is the same and is the most frequent. Therefore, the CPU 201 estimates the container driving unit 207 and the open/close detection sensor 214 as the fault locations of the error being analyzed by the process of S105b.

This failure pattern suggests that a double failure has occurred. Therefore, the CPU 201 can notify the user or CE that multiple failures need to be repaired or dealt with during maintenance. This makes it possible to provide useful information for planning maintenance and preparing replacement parts.

The failure pattern shown in FIG. 15(c) represents a failure state in which the operating period between the analysis target error and the first related error is long, and the operating period between the analysis target error and the second related error is short. In other words, FIG. 15(c) is a case in which failure patterns No. 5 and No. 7 in FIG. 12 occur. Therefore, the CPU 201 estimates the failure location based on failure patterns No. 5 and No. 7 using the process in FIG. 13 and the failure estimation table shown in FIG. 12. In the case of failure pattern No. 5, the CPU 201 estimates the failure location to be the container drive unit 207. Similarly, in the case of failure pattern No. 7, the CPU 201 estimates the failure location to be either the container drive unit 207, the link member 3011, or the link shaft 7001.

Furthermore, as before, the CPU 201 performs the process of S105b in FIG. 17, which is the second fault estimation. In this case, since the estimation frequency of the container drive unit 207 is the highest, the CPU 201 estimates that the container drive unit 207 is the faulty part of the error being analyzed. Therefore, the CPU 201 can notify the user or CE that the fault will be resolved if the container drive unit 207 is repaired or treated during maintenance, and can provide information that is useful for preparing replacement parts and shortening the work time during maintenance.

The failure pattern shown in FIG. 15(d) represents a failure state in which the operating period between the analysis target error and the first and second related errors is long. In other words, FIG. 15(d) is a case in which failure patterns No. 5 and No. 8 in FIG. 12 have occurred. Therefore, the CPU 201 estimates the failure location based on failure patterns No. 5 and No. 8 using the processing in FIG. 13 and the failure estimation table shown in FIG. 12. In the case of failure pattern No. 5, the CPU 201 estimates the failure location to be the container drive unit 207. Similarly, in the case of failure pattern No. 8, the CPU 201 estimates the failure location to be the open/close detection sensor 214.

Furthermore, similarly to the above, the CPU 201 performs the process of S105b in FIG. 17, which is the second fault estimation. In this case, the estimation frequencies of the container drive unit 207 and the open/close detection sensor 214 are the same and are the most frequent. Therefore, based on the second fault estimation, the CPU 201 estimates that the container drive unit 207 and the open/close detection sensor 214 are the fault locations of the error being analyzed. This fault pattern suggests that a double fault has occurred. Therefore, the CPU 201 can notify the user or CE that multiple faults need to be repaired and addressed during maintenance. This makes it possible to provide useful information for planning maintenance and preparing replacement parts.

The failure pattern shown in FIG. 16(a) represents a state in which the operating period between the error to be analyzed and the first related error is short, and the operating period between the error to be analyzed and the second related error is longer than the intermittent failure pattern. In this case, multiple related errors have occurred, but only one related error has occurred within threshold B. Therefore, the CPU 201 determines that only the first related error has occurred for the error to be analyzed. Specifically, the CPU 201 determines that failure pattern No. 4 in FIG. 12 has occurred. Therefore, the CPU 201 estimates that the container drive unit 207 is the failure location of the error to be analyzed.

The failure pattern shown in FIG. 16(b) represents a state in which the operating period between the error to be analyzed and the first related error is longer than that of the intermittent failure pattern, and the operating period between the error to be analyzed and the second related error is longer. In this case as well, the CPU 201 determines that only the second related error has occurred for the error to be analyzed. Specifically, the CPU 201 determines that failure pattern No. 8 in FIG. 12 has occurred. Therefore, the CPU 201 estimates that the open/close detection sensor 214 is the failure location of the error to be analyzed.

In other words, even if multiple related errors occur for the error being analyzed, the CPU 201 will not determine that they are related errors unless they occur within threshold B, and will perform a fault inference assuming that only a related error within threshold B (in this example, only the second related error) has occurred alone.

The failure pattern shown in FIG. 16(c) represents a state in which the operating periods between the analysis target error and the first related error and between the analysis target error and the second related error are both longer than the intermittent failure pattern. Therefore, the CPU 201 performs a failure estimation similar to that of the failure pattern in FIG. 11(d).

In the second fault estimation described above, when multiple related errors occur, the fault location of the error being analyzed is estimated by combining the estimation results from each fault pattern. This makes it possible to estimate the fault location more clearly than when the judgment results of each fault pattern are individually estimated as the fault location, and to obtain advanced information about the fault location. In other words, the CPU 201 can provide the user or CE with useful information that will lead to the preparation of parts required for treatment, the time required for treatment, and a reduction in treatment time during maintenance of the fault location.

(Modification)
In the above example, a configuration has been described in which error-related information is stored in the in-machine data storage memory 204 in the image forming apparatus 100, and the CPU 201 reads the error-related information from the in-machine data storage memory 204 to estimate the location of the failure. In this example, a case will be described in which these processes are performed by an information processing device provided outside the image forming apparatus 100.

Figure 18 is a configuration diagram of a fault estimation system that estimates the fault location of an image forming device using an external information processing device. The fault estimation system 1500 includes one or more image forming devices 1501, 1502, a server 1503, and a management device 1504. Here, two image forming devices 1501, 1502 are provided in the fault estimation system 1500. The image forming devices 1501, 1502 are configured by adding a network interface to the image forming device 100, and form an image on a sheet S to create a deliverable. The server 1503 and management device 1504 function as information processing devices that estimate the fault location based on in-machine data.

The image forming apparatuses 1501 and 1502, the server 1503, and the management apparatus 1504 can communicate with each other via a network. Here, the network is the Internet 1505. The network may be a telecommunications line such as a LAN (Local Area Network) or a WAN (Wide Area Network). The fault estimation system 1500 collects data from the image forming apparatuses 1501 and 1502, and estimates the cause of the fault for each of the image forming apparatuses 1501 and 1502 based on the collected data.

When an error occurs, each of the image forming devices 1501 and 1502 sends error-related information about the error to the server 1503.

The server 1503 accumulates the error-related information, which is in-machine data acquired from each of the image forming devices 1501 and 1502, for each of the image forming devices 1501 and 1502 acquired. The server 1503 also transmits the received error-related information and error-related information of errors that have occurred in the same image forming device in the past to the management device 1504.

Figure 19 is a configuration diagram of the management device 1504. The management device 1504 includes a CPU 1601, a memory 1602, a storage 1603, a network interface (I/F) 1604, and an operation unit 1606. The CPU 1601, the memory 1602, the storage 1603, and the network I/F 1604 are communicatively connected via a system bus 1605.

The CPU 1601 controls the operation of the entire management device 1504. The memory 1602 stores the startup program of the CPU 1601 and data required for executing the startup program. The storage 1603 is a storage device with a larger capacity than the memory 1602, such as an HDD (Hard Disk Drive) or an SSD (Solid State Drive). The storage 1603 stores the control program executed by the CPU 1601, etc.

The CPU 1601 executes a startup program stored in the memory 1602 when the management device 1504 is started. The startup program is a program for expanding the control program stored in the storage 1603 into the memory 1602. The CPU 1601 executes the control program expanded into the memory 1602 and performs various controls. The CPU 1601 also communicates with other devices such as the server 1503 via the Internet 1505 through the network I/F 1604. The operation unit 1606 has the same functions as the operation unit 205. The operation unit 1606 inputs an instruction to the CPU 1601 to display the fault estimation result. The operation unit 1606 also displays the fault estimation result under the control of the CPU 1601.

The CPU 1601 performs the processes in FIG. 13, FIG. 14, and FIG. 17 based on the error-related information received from the server 1503 to estimate the location of the failure. The CPU 1601 transmits the result of the estimation of the location of the failure to the server 1503. The server 1503 stores the received result of the estimation of the location of the failure.

When an instruction to display the failure estimation result is input from the operation unit 1606, the CPU 1601 obtains the estimation result of the failure location from the server 1503 and displays information about the failure location on the operation unit 1606. The CPU 1601 may display not only the failure location but also maintenance-related information on the operation unit 1606. The maintenance-related information is, for example, a part replacement procedure and an estimated work time required for maintenance. In this way, the failure location of the image forming apparatuses 1501 and 1502 managed by the failure estimation system 1500 is estimated, and maintenance work is performed.

The image forming device 100 and fault estimation system 1500 of this embodiment as described above estimate the fault location that caused the error based on the error occurrence pattern (error occurrence interval) determined using only the counter value included in the error-related information. This makes it possible to estimate the fault location with high accuracy without using a large amount of in-machine data such as sensor detection values and image forming device control values.

Claims (10)

A component used for forming an image on a sheet;
detection means for detecting an error in the operation of said component;
a storage means for storing fault estimation information indicating a relationship between a fault location that may be the cause of the error and an interval at which the error occurs;
and a control means for determining an occurrence interval between an error of an analysis object detected by the detection means and an associated error related to the error of the analysis object, performing a first fault estimation for estimating a fault location of the error of the analysis object based on the occurrence interval determined as the fault estimation information, and, when there are a plurality of associated errors, performing a second fault estimation for estimating a fault location of the error of the analysis object by combining the plurality of fault locations estimated by the first fault estimation.
Image forming device. the control means determines a most frequent fault location among the plurality of fault locations estimated by the first fault estimation as the fault location of the error to be analyzed,
2. The image forming apparatus according to claim 1. a storage unit for storing error-related information including an error code representing a type of the error;
the fault estimation information includes, for each combination of an error code of the error to be analyzed and an error code of the associated error, information indicating a relationship between a fault location that may be the cause of the error to be analyzed and a fault pattern due to an occurrence interval between the error to be analyzed and the associated error,
3. The image forming apparatus according to claim 1. the error-related information further includes a counter value indicating an operating state of the image forming apparatus when the error occurred,
the control means determines the failure pattern from a counter value included in the error related information of the error to be analyzed and a counter value included in the error related information of the related error, and estimates a failure location according to the failure pattern.
4. The image forming apparatus according to claim 3. The failure estimation information further includes a threshold value for determining a failure pattern,
the control means determines a failure pattern based on a difference between a counter value included in the error-related information of the error to be analyzed and a counter value included in the error-related information of the associated error, and the threshold value.
5. The image forming apparatus according to claim 4. the failure estimation information includes a first threshold value for determining a failure pattern and a second threshold value that is greater than the first threshold value;
the control means determines a failure pattern based on a difference between the counter value included in the error-related information of the error to be analyzed and a counter value included in the error-related information of the associated error, and based on the first threshold value and the second threshold value.
6. The image forming apparatus according to claim 5. The threshold value is a value calculated based on a period of operation of the image forming apparatus until an error is determined.
6. The image forming apparatus according to claim 5. The failure estimation information is a table stored in the storage means.
2. The image forming apparatus according to claim 1. The control means displays information about the estimated fault location on a predetermined display.
2. The image forming apparatus according to claim 1. An information processing apparatus connected via a network to one or more image forming apparatuses including components used for forming an image on a sheet and a detection unit for detecting an error in the operation of the components,
a storage unit that stores error-related information regarding the error acquired from the image forming apparatus via the network;
a storage means for storing fault estimation information indicating a relationship between a fault location that may be the cause of the error and an interval at which the error occurs;
and a control means for determining an occurrence interval of the error of the analysis object and the associated errors from error-related information of the error of the analysis object detected by the detection means and error-related information of associated errors related to the error of the analysis object, performing a first fault estimation for estimating a fault location of the error of the analysis object based on the fault estimation information and the occurrence interval, and, when there are a plurality of associated errors, performing a second fault estimation for estimating a fault location of the error of the analysis object by combining the plurality of fault locations estimated by the first fault estimation.
Information processing device.

Images