Patent Publication Number: US-11036570-B2

Title: Device management system and device management apparatus

Description:
CROSS-REFERENCE TO RELATED PATENT APPLICATION 
     This application claims the benefit of Japanese Priority Patent Application JP 2019-119953 filed Jun. 27, 2019, the entire contents of which are incorporated herein by reference. 
     FIELD OF THE DISCLOSURE 
     The present disclosure relates to a device management system including multiple image forming apparatuses. Further, the present disclosure relates to a device management apparatus that communicates with the multiple image forming apparatuses. 
     FIELD OF THE DISCLOSURE 
     An image forming apparatus has a component which should be replaced according to its lifetime. Such a component will be hereinafter referred to as a “maintainable component”. 
     SUMMARY OF THE DISCLOSURE 
     It is desirable that a maintainable component should be replaced at appropriate timing. 
     According to the present embodiment, there is provided a device management system, including: 
     multiple image forming apparatuses; and 
     a device management apparatus communicably connected to the multiple image forming apparatuses via a network, 
     the image forming apparatus including
         a maintainable component being a replaceable component,   a storage device configured to store a threshold of a parameter, the parameter being obtained after an operation, where an operation about the maintainable component is treated as a normal operation, and   a communication device configured to, where the parameter exceeds the threshold after an operation and where the maintainable component has a failure, send a cumulative number of fed sheets at that time to the device management apparatus,       

     the device management apparatus including
         a storage device configured to store a number of fed sheets in an early failure period, the number of fed sheets in the early failure period being a certain number of fed sheets and being a preset number of fed sheets, which is treated as an early failure where the maintainable component has a failure, and   a controller circuitry configured to
           calculate a failure density depending on a number of fed sheets based on a number of fed sheets at a time when a failure occurred in the maintainable component, which is received from the multiple image forming apparatuses, and   output information about replacement of the maintainable component based on the failure density to the number of fed sheets in the early failure period from a number of fed sheets at a time when the parameter exceeds the threshold after an operation, which is received from one image forming apparatus.   
               

     According to the present embodiment, there is provided a device management apparatus, including: 
     a communication device configured to communicably connected to an image forming apparatus via a network, 
     the image forming apparatus including
         a maintainable component being a replaceable component,   a storage device configured to store a threshold of a parameter, the parameter being obtained after an operation, where an operation about the maintainable component is treated as a normal operation, and   a communication device configured to, where the parameter exceeds the threshold after an operation and where the maintainable component has a failure, send a cumulative number of fed sheets at that time to the device management apparatus;       

     a storage device configured to store a number of fed sheets in an early failure period, the number of fed sheets in the early failure period being a certain number of fed sheets and being a preset number of fed sheets, which is treated as an early failure where the maintainable component has a failure; and
         a controller circuitry configured to
           calculate a failure density depending on a number of fed sheets based on a number of fed sheets at a time when a failure occurred in the maintainable component, which is received from the multiple image forming apparatuses, and   output information about replacement of the maintainable component based on the failure density to the number of fed sheets in the early failure period from a number of fed sheets at a time when the parameter exceeds the threshold after an operation, which is received from one image forming apparatus.   
               

     These and other objects, features and advantages of the present disclosure will become more apparent in light of the following detailed description of best mode embodiments thereof, as illustrated in the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a configuration of a device management system according to an embodiment of the present disclosure; 
         FIG. 2  shows a hardware configuration of an image forming apparatus; 
         FIG. 3  shows a hardware configuration of a device management apparatus; 
         FIG. 4  shows an operational flow of the device management system; and 
         FIG. 5  shows a maintenance determination process based on a failure density and the number of fed sheets. 
     
    
    
     DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS 
     In the following embodiment, a “maintainable component” is a “feed roller”, an “operation about the maintainable component” is a “feeding (operation)”, and a “parameter obtained after an operation” is a “time-length-for-feeding”, which are merely examples. 
     1. Device Management System 
       FIG. 1  shows a configuration of a device management system according to an embodiment of the present disclosure. 
     The device management system  1  is a computer system in which the multiple image forming apparatuses  10  communicate with the device management apparatus  30  via the network N. The network N is, for example, the Internet. The image forming apparatus  10  is, for example, an MFP (Multifunctional Peripheral). The device management apparatus  30  is a typical computer and functions as a server apparatus. 
     2. Hardware Configuration of Image Forming Apparatus 
       FIG. 2  shows a hardware configuration of an image forming apparatus. 
     A hardware configuration of the image forming apparatus  10  will be described. The image forming apparatus  10  includes the controller circuitry  11 . The controller circuitry  11  includes the CPU (Central Processing Unit)  11   a , the RAM (Random Access Memory)  11   b , the ROM (Read Only Memory)  11   c , dedicated hardware circuitries, and the like and performs overall operational control of the image forming apparatus  10 . The CPU  11   a  loads information processing programs stored in the ROM  11   c  in the RAM  11   b  and executes the information processing programs. The ROM  11   c  is a nonvolatile memory that stores programs executable by the CPU  11   a , data, and the like. The ROM  11   c  is an example of a non-transitory computer readable recording medium. 
     The controller circuitry  11  is connected to the image scanner  12 , the image processor  14  (including GPU (Graphics Processing Unit)), the image memory  15 , the image forming device  16  (printer), the operation device  17  including the display device  17   a  (touch panel), the large volume nonvolatile storage device  18  such as an HDD (Hard Disk Drive) or an SSD (Step Solid State Drive), the facsimile communication device  19 , the network communication interface  13 , and the like. The controller circuitry  11  performs operational control of the respective devices connected thereto and sends/receives signals and data to/from those devices. The operation device  17  (touch panel) is one mode of an input device. A sound input device including a microphone may be provided as an input device. 
     3. Hardware Configuration of Device Management Apparatus 
       FIG. 3  shows a hardware configuration of a device management apparatus. 
     The device management apparatus  30  includes the CPU  31 , the ROM  32 , the RAM  33 , the storage device  34 , which is a large-volume nonvolatile memory such as an HDD or an SSD, the network communication interface  35 , the operation device  36 , and the display device  37 , and the bus  38  connecting them to each other. 
     The controller circuitry  300  includes the CPU  31 , the ROM  32 , and the RAM  33 . The CPU  31  loads information processing programs stored in the ROM  32  in the RAM  33  and executes the information processing programs. The ROM  32  stores programs executable by the CPU  31 , data, and the like nonvolatile. The ROM  32  is an example of a non-transitory computer readable recording medium. 
     4. Operational Flow of Device Management System 
       FIG. 4  shows an operational flow of the device management system. 
       FIG. 4  also shows a functional configuration of the device management system  1 . In the image forming apparatus  10 , the image forming device  16  includes, as a maintainable component, the feed roller  161 . In the image forming apparatus  10 , the storage device  18  stores the cumulative number of fed sheets  181 , the time-length-for-feeding threshold  182 , and the production class information  183 . 
     The feed roller  161  has one of various “production classes”. The production class information  183  is information for specifying the production class. The “production class” is for example, a production lot of the feed roller  161 . In this case, the production class information  183  is a lot number. 
     The cumulative number of fed sheets  181  is a counted value of the number of sheets fed into the image forming device  16 . The cumulative number of fed sheets  181  is about a number of use of the image forming apparatus  10  by users. In the present embodiment, every time the feed roller  161  is replaced, the cumulative number of fed sheets  181  at the time of replacement is also stored in the storage device  18 . 
     The time-length-for-feeding threshold  182  is a threshold, where a “time-length-for-feeding” is treated as a normal operation as a design specification. The “time-length-for-feeding” is a time length that a sheet travels from a feeder (not shown) to the main part of the image forming device  16  by using the feed roller  161 . A manager of the device management system  1  sets a certain value (or range) as the time-length-for-feeding threshold  182 . 
     (Step S 1 : Initial setting) In the image forming apparatus  10 , the controller circuitry  11  stores the time-length-for-feeding threshold  182  in the storage device  18  depending on an operational input of a user input from the operation device  17 . 
     Meanwhile, in the device management apparatus  30 , the controller circuitry  300  stores the number of fed sheets in early failure period  341  in the storage device  34 , which is specified by the manager of the device management system  1 . Note that the image forming apparatus  10  may store the time-length-for-feeding threshold  182  based on a command sent from the device management apparatus  30  to the image forming apparatus  10 . 
     (Step S 2 : Normal operation) Every time a feed operation using the feed roller  161  is executed in response to an operation input by a user, the controller circuitry  11  detects the “time-length-for-feeding”, which is a time length required for the feed operation. Further, the controller circuitry  11  detects whether or not a failure of the feed roller  161  occurs. If a failure of the feed roller  161  is detected, the controller circuitry  11  notifies the device management apparatus  30  of that fact. Also, if the time-length-for-feeding exceeds the time-length-for-feeding threshold  182 , the controller circuitry  11  notifies the device management apparatus  30  of that fact. 
     (Step S 3 : Notification to device management apparatus) If the feed roller  161  has a failure, the controller circuitry  11  sends a signal, which notifies the device management apparatus  30  of that fact. Also, if the time-length-for-feeding exceeds the time-length-for-feeding threshold  182 , the controller circuitry  11  sends a signal, which notifies the device management apparatus  30  of that fact. At those times, the controller circuitry  11  also notifies the device management apparatus  30  of the cumulative number of fed sheets  181  (the cumulative number of fed sheets  181  from the last replacement to the failure) at that time and the production class information  183  of the feed roller  161 . 
     (Step S 4 : Analysis of failure density) The controller circuitry  300  of the device management apparatus  30  receives the failure notification, and stores the number of fed sheets  342  at the time of the failure occurrence in the storage device  34 . The controller circuitry  300  calculates “the failure density depending on the number of fed sheets  343 ” for each production class specified based on the production class information  183  based on the number of fed sheets  342  at the failure occurrence received from the multiple image forming apparatuses  10 . “The failure density depending on the number of fed sheets  343 ” is represented by the following failure index density function based on the Weibull distribution. 
     
       
         
           
             
               
                 
                   
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     In the expression, α is a Weibull factor (shape parameter), β is a scale parameter, and x is the number of fed sheets. In other words, x is the cumulative number of fed sheets  181  at the time of a failure of the feed roller  161 , which is a maintainable component, from the last replacement to the failure. 
     (Step S 5 : Maintenance determination) The device management apparatus  30  receives a notification, which indicates that the time-length-for-feeding exceeds the time-length-for-feeding threshold  182 , from the image forming apparatus  10 . In this case, the device management apparatus  30  uses the failure density function of the production lot of the feed roller  161 , which is used in the image forming apparatus  10 . Then the device management apparatus  30  calculates the occurrence probability of early failures until it reaches the number of fed sheets in early failure period  341 . In this case, the number of fed sheets in early failure period  341  is, as described above, a certain number of fed sheets and is a preset number of fed sheets, which is treated as an early failure if the feed roller  161  has a failure. In other words, the number of fed sheets in early failure period  341  is the maximum value of the number of fed sheets treated as an early failure period. 
     Further, the controller circuitry  300  calculates the early failure occurrence probability (in other words, cumulative value of failure density  343 ) until the number of fed sheets in early failure period is attained (the cumulative number of sheets is reset after replacement) based on the failure density function of the production lot of a replaceable component. The controller circuitry  300  compares the both, and determines that the component should be replaced where the occurrence probability after replacement is lower than the other. Where the early failure occurrence probability after replacement is not lower than the other, the controller circuitry  300  determines that the component should be maintained without replacement. 
     According to the aforementioned operational flow, the time-length-for-feeding exceeds the time-length-for-feeding threshold  182 , i.e., a so-called sign of failure, is detected. At the time of detection, the image forming apparatus  10  notifies the device management apparatus  30  of that fact (Step S 2 ). As a result, the device management apparatus may determine the maintenance before a failure actually occurs (Step S 5 ), and it is possible to prevent occurrence of an early failure and occurrence of downtime resulting from that in advance. 
       FIG. 5  shows a maintenance determination process based on a failure density and the number of fed sheets. In  FIG. 5 , the number of fed sheets in early failure period  341  is “1000 sheets”. As shown in  FIG. 5 , for example, the failure density of the feed roller  161  of the first production class changes depending on the number of fed sheets. As shown in  FIG. 5 , for example, the failure density of the feed roller  161  of the first production class also changes depending on the number of fed sheets. Note that, typically, the failure density for a while after a maintainable component is replaced (before the early failure period passes) is higher than the failure density after the early failure period passes. After the early failure period passes, the failure density becomes stable. 
     Hereinafter, the first production class is the “early lot”, and the second production class is the “later lot”. 
     In  FIG. 5 , the time-length-for-feeding exceeds the time-length-for-feeding threshold  182  at the time of feeding the 200th sheet (Q). In this case, in the span Q to P 1  (in other words, span from start of use of early lot component to the number of fed sheets in early failure period  341  “1000 sheets”), the cumulative value (area below curve) of the failure density of the early lot is obtained. The cumulative value is the early failure occurrence probability where the early lot component is used without being replaced. Meanwhile, in the span Q to P 2  (in other words, where early lot component is replaced by later lot component at time (Q), span from start of use of later lot component to the number of fed sheets in early failure period  341  “1000 sheets”), the cumulative value of the failure density of the later lot is obtained. The cumulative value is the early failure occurrence probability where the early lot component is replaced by the later lot component. 
     The device management apparatus  30  compares the cumulative value of the failure density in the span Q to P 1  against the cumulative value of the failure density in the span Q to P 2 , and determines maintenance. In the example of  FIG. 5 , the latter is smaller. So the device management apparatus  30  determines that the early lot component should be replaced by the later lot component. 
     5. Modification Example 
     In the present embodiment, the “maintainable component” is a “feed roller”, for example. Alternatively, for example, the “maintainable component” may be a “conveyer roller”, a “fuser roller”, or an “intermediate transfer belt”. Where each of them is a maintainable component, for example, the time that takes for a conveyer operation or the time that takes for a fuser operation of fusing a formed image on a sheet may be a “parameter”. 
     6. Conclusion 
     A “wear-out failure” occurs as a result of wear-out of a maintainable component as a result of printing. With regard to replacement timing, typically, a service person visits a customer site regularly, and then determines whether or not it is necessary to replace a maintainable component. A service person does not want to bring heavy spares for all the maintainable components for regular visits. So the service person has to select necessary maintainable components for replacement based on the service person&#39;s experiences and the like. 
     (1) According to the present embodiment, one image forming apparatus obtains a parameter, the parameter being obtained after an operation, where an operation about the maintainable component is treated as a normal operation. Where the parameter exceeds the threshold, the image forming apparatus sends a cumulative number of fed sheets at that time to a device management apparatus. Meanwhile, the device management apparatus receives a cumulative number of fed sheets at a time when a failure occurred in the maintainable component from the image forming apparatus that has the failure. Based on that, the device management apparatus calculates a failure density depending on a number of fed sheets. The device management apparatus outputs information about replacement of the maintainable component of the one image forming apparatus based on the failure density to the predetermined number of fed sheets in the early failure period from a number of fed sheets at a time when the parameter exceeds the threshold. As a result, according to the present embodiment, information about replacement of a maintainable component may be output appropriately based on an early failure occurrence probability. 
     (2) According to the present embodiment, the device management apparatus calculates the failure density for each production class (production time, lot, etc.) of the maintainable component. As a result, according to the present embodiment, an early failure occurrence probability, which is different depending on difference of lots of maintainable components, may be calculated. So information about replacement of a maintainable component may be output more appropriately. 
     (3) According to the present embodiment, the device management apparatus outputs information about replacement of the maintainable component further based on the failure density calculated for the maintainable component of a second production class, the second production class being different from a production class (first production class) of the maintainable component about an operation, where the parameter exceeds the threshold. As a result, according to the present embodiment, production classes of maintainable components are compared against one another. So information about replacement of a maintainable component may be output more appropriately. 
     It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and alterations may occur depending on design requirements and other factors insofar as they are within the scope of the appended claims or the equivalents thereof