Patent ID: 12244775

DESCRIPTION OF THE EMBODIMENTS

Hereinafter, embodiments will be described in detail with reference to the attached drawings. Note, the following embodiments are not intended to limit the scope of the claimed invention. Multiple features are described in the embodiments, but limitation is not made to an invention that requires all such features, and multiple such features may be combined as appropriate. Furthermore, in the attached drawings, the same reference numerals are given to the same or similar configurations, and redundant description thereof is omitted.

First Embodiment

FIG.1is a schematic configuration diagram of an image forming apparatus PR according to the present embodiment. The image forming apparatus PR includes cartridges5Y,5M,5C and5K configured to form yellow, magenta, cyan and black toner images on an intermediate transfer member11. Although the cartridges5Y,5M,5C and5K contain toner of different colors, the configurations thereof are similar and therefore the cartridges5Y,5M,5C and5K will be collectively referred to as a cartridge5in the following description. The cartridge5, including a photoconductor1, a charging roller2, and a developing roller3, is configured to be attachable to and detachable from the main body of the image forming apparatus PR. In other words, the cartridge5is a replacement unit for the image forming apparatus PR. A photoconductor1is rotationally driven in a clockwise direction in the figure in forming an image. The charging roller2charges the surface of the photoconductor1. A scanning unit8exposes each of the photoconductors1based on image data, and forms an electrostatic latent image on each of the photoconductors1. The developing roller3forms a toner image on the photoconductor1by developing the electrostatic latent image on the photoconductor1with toner. Primary transfer rollers10Y,10M,10C and10K respectively transfer, to the intermediate transfer member11, the toner images on the photoconductors1of the cartridges5Y,5M,5C and5K.

An intermediate transfer member unit includes the intermediate transfer member11, a plurality of rollers including the driving roller15configured to stretch the intermediate transfer member11, and the primary transfer rollers10Y,10M,10C and10K. The intermediate transfer member unit is a replacement unit for the image forming apparatus PR. In image formation, the driving roller15is rotationally driven in a counterclockwise direction in the drawing by a motor not illustrated. Accordingly, the intermediate transfer member11is also rotationally driven in the counterclockwise direction in the drawing. Therefore, the toner image on the intermediate transfer member11is conveyed to a position facing a secondary transfer roller14.

A feeding roller22of the feeding unit20feeds a printing material S stored in a cassette21to a conveyance path of the image forming apparatus PR. A conveying roller23conveys the printing material S, fed by the feeding roller22, to downstream side. A separation roller24is provided in order to prevent double feed. A registration roller25conveys the printing material S toward the position facing the secondary transfer roller14. The feeding roller22, the conveying roller23, and the registration roller25are replacement units for the image forming apparatus PR, respectively. The secondary transfer roller14transfers the toner image on the intermediate transfer member11to the printing material S. A fixing unit30, including a fixing film31and a pressure roller32, fixes the toner image on the printing material S by heating and pressing the printing material S. The fixing unit30is a replacement unit for the image forming apparatus PR. After the toner image is fixed, the printing material S is discharged to the outside of the image forming apparatus by a discharging roller33. A conveyance sensor90, which is provided downstream side of the registration roller25, detects the printing material S. A reception unit71configured to receive sound waves is provided between the conveyance sensor90and the secondary transfer roller14. For example, the reception unit71includes a Micro Electro Mechanical System (MEMS) microphone configured to convert vibration displacement of a vibration plate caused by pressure into a voltage change and outputs the voltage change. Here, any microphone other than the MEMS microphone, such as a condenser microphone, may be used as long as it can receive sound waves.

FIG.2is a cross-sectional view illustrating an example of the MEMS microphone of the reception unit71. A substrate71bis provided with a MEMS chip71aand an amplifying circuit71c. The MEMS chip71aand the amplifying circuit71care shielded by a shield case72. The shield case72is provided with a sound hole72aconfigured to take in sound waves from the outside. The MEMS chip71aand the amplifying circuit71care electrically connected to each other by a wire71d. The MEMS chip71aincludes a vibration film71fformed on the silicon substrate71eand a back electrode71hprovided facing the vibration film71fand including a large number of sound holes. The vibration film71fand the back electrode71hfacing each other form a capacitor. The silicon substrate71eis provided with a cavity portion71g, and the vibration film71fis provided to cover the cavity portion71g. When a sound wave is input from the sound hole72aprovided in the shield case72, the vibration film71fvibrates, outputting an electric signal in accordance with the vibration status. More specifically, the back electrode71hconverts the change of the capacitance of the capacitor caused by vibration of the vibration film71finto an electric signal, the capacitor being formed by the vibration film71fand the back electrode71h. The electric signal is subjected to amplification process by the amplifying circuit71cand taken out of the MEMS microphone.

FIG.3is a configuration diagram of a sound diagnosis system, or an image forming system, including the image forming apparatus PR. As illustrated inFIG.3, a host computer HC, the image forming apparatus PR, and a server SV which is an information processing apparatus are configured to be communicable with each other via a network, for example. A control unit201of the host computer HC, including a CPU operating as a processor, performs various processes by executing a control program stored in a storage apparatus which is not illustrated. An operation display unit202, including a display, a keyboard, a mouse, or the like, provides a user interface. For example, the control unit201transmits a print job including image data to the image forming apparatus PR in response to a user operation on the operation display unit202, and causes the image forming apparatus PR to form an image based on the image data.

A video controller85of the image forming apparatus PR performs communication with the host computer HC and the server SV. Upon receiving a print job from the host computer HC, the video controller85controls image formation by a printer engine84based on the print job. An operation display unit86, including an operation panel, an operation button, or the like, provides a user interface. The printer engine84includes an engine control unit87including a CPU80that is a processor, a ROM81, and a RAM82. The ROM81is a non-volatile memory configured to store and hold control programs and various data. Here, a rewritable non-volatile memory may be used in place of the ROM81. The RAM82is a volatile memory configured to store temporary data. The CPU80forms an image on the sheet S by executing the control program stored in the ROM81to control, via an I/O port83, respective members illustrated inFIG.1, as well as motors91to95and a solenoid96illustrated inFIG.3.

Here, the feeding motor91is the driving source of the feeding roller22, the conveying roller23, and the registration roller25. The intermediate transfer member motor92is the driving source of the driving roller15. The photoconductor motor93is the driving source of each photoconductor1. The developing motor94is the driving source of each developing roller3. The fixing motor95is the driving source of the pressure roller32of the fixing unit30. The solenoid96is the driving source of a mechanical clutch mechanism (not illustrated) configured to separate the primary transfer roller10from the intermediate transfer member11when image formation is not performed, and bring the primary transfer roller10to abut against the intermediate transfer member11during image formation.

A calculation unit301of the server SV, including one or more processors (CPUs), executes a control program stored in the storage apparatus302to perform various processes described below. A storage apparatus302includes an arbitrary type of volatile and non-volatile storage devices. The storage apparatus302also stores data to be used by the calculation unit301in various processes, in addition to the program to be executed by the calculation unit301. Although the storage apparatus302is a component of the server SV in the present embodiment, some or all of the data described below as being stored in the storage apparatus302may be stored in an external apparatus that can be accessed from the server SV via a network.

FIG.4is a functional block diagram of the sound diagnosis system illustrated inFIG.3according to the present embodiment. The functional blocks illustrated inFIG.4may be realized by executing corresponding control programs by the CPU80of the engine control unit87of the image forming apparatus PR and the CPU of the calculation unit301of the server SV, respectively.

Upon receiving a print job, a received sound processing unit70performs processing of a sound signal received and output from the reception unit71in a predetermined period described below. A received sound amplification unit732amplifies the sound signal provided from the reception unit71. An analog-to-digital (AD) conversion unit733converts the sound signal output from the received sound amplification unit732into a digital signal (digital value). The sound signal output from the reception unit71includes DC components, and therefore a reference value setting unit734subtracts a reference value from each value indicated by the digital signal from the AD conversion unit733, and extracts only the components related to pressure variation of the sound. Here, the reference value is set by the CPU80.

The filter calculation unit735performs a filtering process by applying a filter on the digital signal from the reference value setting unit734to which the DC components is removed. Here, the filter calculation unit735, including a plurality of filters, performs the filtering process using a filter set by the CPU80. A square calculation unit736performs square calculation of digital signals subjected to the filtering process. A section mean calculation unit737performs section mean calculation of the digital signals subjected to the square calculation. In the present embodiment, the time section for which the section mean calculation is performed is set to 100 ms, for example. Here, the time length in which the section mean calculation is performed is not limited to the foregoing, and may be different for each measurement. By performing square calculation and section mean calculation, the sound wave level L indicating the degree of sound pressure variation for each time section is obtained. The section mean calculation unit737stores a sound wave level L of each time section in a sound information storage unit738.

At this time, a status notification unit731determines the operation status of each of the motors91to95and the solenoid96, i.e., whether or not they are operating, and associates the sound wave level L in the time section with the operation status of the respective motors91to95and the solenoid96in the time section. Note that in the following description, the motors91to95and the solenoid96are collectively referred to as an “actuator”. The sound information storage unit738stores, for each time section, information indicating the operation status of each actuator in the time section and the sound wave level L in the time section. When the operation status of the actuator is changing in the middle of the time section, an operation status with a longer operation time in the time section is used, for example. In the following, information stored in the sound information storage unit738, which indicates a time section, the operation status of each actuator in the time section, and the sound wave level L in the time section, will be referred to as sound data. Single sound data is a piece of information indicating the operation status of each actuator and the sound wave level L for each of a plurality of successive time sections. Furthermore, single sound data may be associated with print setting information such as the type of filter applied by the filter calculation unit735, or the type (or basis weight) of the sheet S used for printing. As such, sound data is generated by the image forming apparatus PR in the present embodiment. The sound information storage unit738transmits the sound data to the server SV. The server SV stores the sound data acquired from the image forming apparatus PR in the storage apparatus302.

A lifetime counting unit739counts the remaining lifetime of components (replacement units) such as the cartridge5, the intermediate transfer member unit, each roller conveying a sheet, and the fixing unit30. For example, a number of printable sheets is set for each replacement unit. The lifetime counting unit739determines such that the remaining lifetime is 100% when the number of printed sheets, after the use of the replacement unit is started, is 0, and that the remaining lifetime is 0% when the number of printed sheets, after the use of the replacement unit is started, reaches the number of printable sheets of the replacement unit. The lifetime counting unit739notifies the server SV of the remaining lifetime of each replacement unit. The server SV stores, in the storage apparatus302, the information indicating the remaining lifetime of each replacement unit acquired from the image forming apparatus PR.

Next, a process performed by the server SV will be described. A classification unit3010classifies and groups the sound data stored in the storage apparatus302. The grouping is performed based on the difference of the operation status of respective actuators of a plurality of time sections of single sound data. Specifically, a plurality of sound data having a same operation status of each actuator of a plurality of time sections are grouped in a same group. The grouping may be performed further based on filters applied in generation of the sound data. In this case, for example, even when two sound data have same operation status of each actuator in each of the plurality of time sections, if different filters are applied in generating the two sound data, the two sound data belong to different groups. Furthermore, the grouping may be performed based on print setting information. In this case, for example, even when two sound data have same operation status of each actuator in each of the plurality of time sections, if different types of the sheet S are being conveyed in acquiring the two sound data, the two sound data belong to different groups.

As will be described below, a statistic value calculation unit3011calculates, for each group, a statistic value P for each time section based on a plurality of sound data in a same group. As such, the processing described below is performed independently for each group. In the following description, therefore, a process is intended to be independently performed for each group even when the phrase “for each group” is omitted, unless explicitly stated that not “for each group”. As will be described below, a threshold value setting unit3012sets a threshold value TH-P for each time section, based on the statistic value P for each time section. As will be described below, a determination unit3013uses the threshold value TH-P of each time section to determine whether or not an abnormal sound is generated. Furthermore, upon determining that the abnormal sound is generated, the determination unit3013determines the replacement unit generating the abnormal sound. A notification unit3014notifies the determination result by the determination unit3013. Here, the notification destination may be a user of the image forming apparatus PR or the host computer HC used by a dealer or the like who performs maintenance and management of the image forming apparatus PR.

In the present embodiment, single sound data is acquired in a period from a timing when the last sheet S of the one or more sheets S to which an image is formed in a single print job has reached a predetermined position to a timing after all the actuators of the image forming apparatus PR stopped. In this example, the timing when the sheet S has reached the predetermined position is assumed to be the timing when the trailing edge of the sheet S has passed through a position at which the conveyance sensor90detects the sheet S. In addition, the length of the period in which single sound data is acquired is assumed to be 1600 ms. In this example, the length of a time section is 100 ms, and therefore single sound data is divided into 16 successive time sections, and is data indicating the sound wave level L in each time section and the operation status of each actuator.

The period from the timing when the trailing edge of the last sheet S in a single print job has passed through the conveyance sensor90to the timing when all the actuators of the image forming apparatus PR stop includes a period in which the sheet S is not being conveyed in the vicinity of the reception unit71, which is a period in which the operating sound of each actuator in the image forming apparatus PR can be easily received. In the following description, a period from a timing when the trailing edge of the last sheet S has passed through the conveyance sensor90to a timing when all the actuators of the image forming apparatus PR stop is referred to as a “post-rotation period”. Here, the period in which the sound data is acquired is not limited to the aforementioned period, and may include, for example, a period after the feeding of the sheet S has started. Furthermore, when there is no need to reduce the processing load of the sound data generation by the image forming apparatus PR or the processing load of the server SV due to an increase of the data amount of sound data, the period from the start of conveyance to the discharge of each sheet S may be set as the acquisition period of single sound data.

FIG.5illustrates a process of setting the threshold value TH-P performed by the server SV. Upon acquiring single sound data from the image forming apparatus PR, the classification unit3010determines a group to which the sound data belongs at S10, and stores the sound data in the storage apparatus302in association with the group to which the sound data belongs. As has been described above, the grouping may be performed based on the difference of the operation status of each actuator in the 16 time sections. Furthermore, the grouping may be performed based on the filter applied, or print setting information.FIGS.6A and6Billustrate two sound data classified in different groups based on the operation status of each actuator. Here, “1” of each actuator in theFIGS.6A and6Bindicates that the actuator is operating (active state) and “0” indicates that the actuator is not operating (an inactive state). The sound data illustrated inFIG.6Aand the sound data illustrated in6B differ in status of the actuator in the shading part, and thus these sound data are grouped in different groups.

When N sound data are newly added to the group, the statistic value calculation unit3011calculates, at S11, a statistic value P for each of the 16 time sections based on the N newest sound data. The statistic value P may be a percentile value of the N sound data, for example. As an example, a 95 percentile value may be set as the statistic value P with N being100. In this case, letting time sections #1to time sections #16be the 16 time sections of single sound data, the value of the fifth highest sound wave level L among the 100 sound wave levels L in the time section #1is the statistic value P for the time section #1.

When the number of the calculated statistic values P has reached M, the threshold value setting unit3012sets, at S12, the threshold value TH-P for each of the 16 time sections based on the M statistic values P. The threshold value TH-P may be a value calculated by adding a predetermined value to the mean of the M statistic values P, for example. For example, M may be set to 100.FIG.7illustrates the sound wave level L, the statistic value P calculated from the sound wave level L, and the threshold value TH-P calculated from the statistic value P. InFIG.7, a value higher than the mean of the M statistic values P by 10 dB is used as the threshold value TH-P. As such, the threshold value TH-P is calculated based on M×N sound wave levels L.

The calculation method of the statistic value P is not limited to the aforementioned method. For example, the statistic value P may be defined as an arbitrary percentile value or the maximum value of the N sound wave levels L. Furthermore, the statistic value P may be defined as the mean of a predetermined number of upper levels of the N sound wave levels L. Similarly, the method of setting the threshold value TH-P is not limited to the aforementioned method. For example, the threshold value TH-P may be a value calculated by increasing the mean or percentile value of the M statistic values P according to a predetermined method.

FIGS.8A to8Crespectively illustrate an example of the threshold value TH-P set for the first time section #1of the 16 time sections. Here, the groups illustrated inFIGS.8A to8Care different from each other. Specifically,FIG.8Ais about a group to which no filter is applied,FIG.8Bis about a group to which a band-pass filter is applied, and theFIG.8Cis about a group to which a high-pass filter is applied.

FIG.9is a flowchart of a process of determining whether or not an abnormal sound is generated and determining a replacement unit generating the abnormal sound. The process illustrated inFIG.9is executed after the threshold value TH-P is set for each of the 16 time sections. Each time sound data is input from the image forming apparatus PR, the classification unit3010groups the sound data, and the statistic value calculation unit3011calculates the statistic value P corresponding to each of the 16 time sections each time N sound data are added to the group. The process illustrated inFIG.9is executed when the statistic value calculation unit3011newly calculates the statistic value P. Here, the statistic value P in the process illustrated inFIG.9is based on the sound data acquired by the server SV after the threshold value TH-P is set, and may be referred to as a “comparison value P” when distinguished from the statistic value P used for calculating the threshold value TH-P.

At S20, the determination unit3013compares the newly calculated statistic value P for each of the 16 time sections with the threshold value TH-P of the corresponding time section. The determination unit3013then determines a section in which the statistic value P is equal to or larger than the threshold value TH-P to be a generation section in which an abnormal sound is generated, and determines the other sections to be non-generation sections in which no abnormal sound is generated. The determination unit3013determines, at S21, a replacement unit that may be generating abnormal sound to be a candidate unit, based on the operation status of the actuator in a period in which a generation section is changing to a non-generation section.

For example, assuming that generation sections and non-generation sections are determined as illustrated inFIG.10. InFIG.10, “NG” indicates a generation section and “OK” indicates a non-generation section. The result illustrated inFIG.10indicates that a generation section is changed to a non-generation section from the time section #8to the time section #9. The actuator which is in an active state in the time section #8and has transited to an inactive state in the time section #9is the solenoid96. During the post-rotation period, the solenoid96operates to separate the primary transfer roller10from the intermediate transfer member11. Therefore, the reason for the abnormal sound not being generated in the time section #9can be determined that the primary transfer roller10is separated from the intermediate transfer member11. In this case, the intermediate transfer member unit including the primary transfer roller10and the intermediate transfer member11is determined as a candidate unit. Here, the relation between the actuator and the candidate unit that may be generating the abnormal sound is preliminarily stored in the storage apparatus302of the server SV.

At S22, the determination unit3013determines whether or not a candidate unit is determined. For example, when it is determined that no abnormal sound is generated in all the time sections, no candidate unit is determined. When no candidate unit is determined, the determination unit3013terminates the process illustrated inFIG.9. When, on the other hand, a candidate unit is determined, the determination unit3013determines, at S23, whether or not there is only one candidate unit. For example, the intermediate transfer member unit is the only candidate unit in the example illustrated inFIG.10. When there is only one candidate unit, the determination unit3013causes, at S24, the notification unit3014to notify of the generation of the abnormal sound and that one candidate unit is the unit generating the abnormal sound.

When, on the other hand, there are a plurality of candidate units, the determination unit3013advances the process to S25. For example, it is assumed inFIG.10that it is NG until the time section #3and changed to OK in the time section #4. In this case, it is the feeding motor91that is stopping operation at the time section #4. However, the feeding motor91is the driving source of the feeding roller22, the conveying roller23, and the registration roller25, and thus it is impossible to narrow down the units to a single roller. The determination unit3013therefore refers to, at S25, the remaining lifetime of each replacement unit received from the lifetime counting unit739. For example, among the feeding roller22, the conveying roller23, and the registration roller25, when the remaining lifetime of the feeding roller22is shorter than a threshold value and the remaining lifetimes of the other rollers are equal to or longer than the threshold value, the determination unit3013determines, at S25, that the feeding roller22is generating the abnormal sound. As such, upon succeeding in narrowing down the units to a single candidate unit at S25, the determination unit3013advances the process to S24. When, on the other hand, failed to narrow down the units to a single candidate unit by referring to the remaining lifetimes, the determination unit3013causes, at S26, the notification unit3014to notify of the generation of the abnormal sound, and notify of each of a plurality of candidate units that may be generating the abnormal sound. At this time, it may also be configured such that notification is made about, for each of the plurality of candidate units, the remaining lifetime or the probability (degree of likelihood) of generation of the abnormal sound that is calculated based on the remaining lifetime, for example. It may be configured such that notification is made, at S24, only about the fact that an abnormal sound is generated, when at S21there is no actuator which is in an active state in a generation section and is changed to an inactive state in a non-generation section.

As has been described above, according to the present embodiment, a statistic value P of the sound wave level in each time section is calculated from sound data, and based on the statistic value P, the threshold value TH-P which is larger than the statistic value P is set. And then when a new statistic value P is calculated, it is compared with the threshold value TH-P to determine generation of an abnormal sound. The operation status of the actuators in each time section of a same group is identical, and thus by setting a threshold value based on the sound wave level L when the operation status of the actuators are identical, generation of an abnormal sound can be detected with high precision even when the abnormal sound is an unknown sound. In addition, the replacement unit that is quite possible of generating the abnormal sound can be determined, by determining whether or not an abnormal sound is generated for each time section, and determining the actuator whose operation status has changed at a timing when the generation/non-generation of the abnormal sound has changed.

In the process illustrated inFIG.9, generation of an abnormal sound is determined by comparing the statistic value (comparison value) P in a time section based on new sound data with the threshold value TH-P for the time section. Here, in the present embodiment, the comparison value P is calculated in a method similar to that for the statistic value P used for calculating the threshold value TH-P. However, the present invention is not limited to calculating the comparison value P in a method similar to that for the statistic value P used for calculating the threshold value TH-P. For example, it is possible to use a different number of sound data, for example, a smaller number of sound data for calculating the comparison value P compared to the number N of sound data used for calculating the statistic value P which is a base for the threshold value TH-P. Furthermore, the comparison value P may be the mean instead of the percentile value of the sound wave levels L of a plurality of sound data. Furthermore, the comparison value P may be the sound wave level L in each time section of single sound data. In this case, the server SV, upon acquiring single sound data from the image forming apparatus PR, executes the process illustrated inFIG.9.

Second Embodiment

Next, a second embodiment will be explained mainly on differences from the first embodiment.FIG.11is a flowchart of a threshold value setting process according to the present embodiment. Upon acquiring sound data from the image forming apparatus PR, the classification unit3010determines, at S30, a group to which the sound data belongs, similarly to S10of the first embodiment, and stores the sound data in the storage apparatus302in association with the group to which the sound data belongs. Additionally, at this time, the classification unit3010determines, at S31for each actuator, a timing when the operation status changes, calculates a difference value d of the actuator based on the sound wave level L in one or more time sections before and after the timing, and stores the difference value d in the storage apparatus302.

In the case of the sound data illustrated inFIG.12, for example, from the time section #3to the time section #4, the feeding motor91has changed from an active state to an inactive state. From the time section #14to the time section #15, the intermediate transfer member motor92has changed from an active state to an inactive state. From the time section #12to the time section #13, the photoconductor motor93has changed from an active state to an inactive state. From the time section #12to the time section #13, the developing motor94has changed from an active state to an inactive state. From the time section #10to the time section #11, the fixing motor95has changed from an active state to an inactive state. From the time section #8to the time section #9, the solenoid96has changed from an active state to an inactive state. In the present embodiment, the difference value d is acquired by subtracting, from the mean of the sound wave levels L in two time sections that are both in an active state before becoming in an inactive state, the mean of the sound wave levels L in two time sections when they become in an inactive state and subsequent two time sections. The shaded part ofFIG.12indicates time sections used for calculating the difference value d for each actuator.

Although, in the present embodiment, the difference value d is calculated based on two time sections before switching from an active state to an inactive state and two time sections after the switching, the difference value d may be configured to be calculated based on a single time section immediately before switching from an active state to an inactive state and a single time section immediately after the switching. Furthermore, three or more time sections may be used. Additionally, it may also be configured such that the difference value d is also calculated similarly at the timing of switching from an inactive state to an active state.

When N of sound data are newly added to the group, the statistic value calculation unit3011calculates, at S32, a statistic value D based on the N difference values d acquired for each actuator. The statistic value D may be a 95 percentile value similarly to the statistic value P in the first embodiment. Subsequently, the statistic value calculation unit3011calculates, at S33, the statistic value P for each of the time sections used to calculate the difference value d of each actuator. In the case ofFIG.12, for example, the time sections #2to #5and #7to #16are used to calculate the difference value d. Therefore, the statistic value P described in the first embodiment is calculated respectively for the time sections #2to #5and #7to #16. In the following description, the time section used for calculating the difference value d of the actuator is denoted as a time section associated with the actuator. In the case ofFIG.12, for example, the time section associated with the fixing motor95is the time sections #9to #12.

When the numbers of the acquired statistic values D and P reach M, the threshold value setting unit3012sets, at S34, the threshold value TH-D based on the M statistic values D of each actuator. The method of calculating the threshold value TH-D is similar to that of calculating the threshold value TH-P in the first embodiment. In addition, the threshold value setting unit3012sets the threshold value TH-P based on the M statistic values P for each of the time sections for which the statistic values P are calculated. The method of calculating the threshold value TH-P is similar to that of the first embodiment.

FIG.13is a flowchart of a process of determining whether or not an abnormal sound is generated and determining a replacement unit generating the abnormal sound. The process illustrated inFIG.13is executed after the threshold values TH-P and TH-D are set. Here, each time sound data is input from the image forming apparatus PR, the classification unit3010groups the sound data, and the statistic value calculation unit3011calculates the statistic value D and the statistic value P each time N sound data are added to the group. The process illustrated inFIG.13is executed when the statistic value calculation unit3011newly calculates the statistic value P and the statistic value D. Noted that, similarly to the first embodiment, the statistic values D and P in the process illustrated inFIG.13are based on the sound data acquired by the server SV after the threshold values TH-D and TH-P are set. Therefore, the statistic values D and P in the process illustrated inFIG.13may also be referred as a “comparison value D” and a “comparison value P” when distinguishing them from the statistic values D and P used for calculating the threshold values TH-D and TH-P.

At S40, the determination unit3013compares the newly calculated statistic value D of the actuator with the threshold value TH-D of the actuator. The determination unit3013then determines an actuator whose statistic value D is equal to or larger than the threshold value TH-D. The determination unit3013compares, at S41for each of the actuators whose statistic value D is equal to or larger than the threshold value TH-D, the statistic value P and the threshold value TH-P in the time section associated with the actuator.

For example, assuming that the statistic value D of the fixing motor95among the actuators illustrated inFIG.12is equal to or larger than the threshold value TH-D of the fixing motor95, and the respective statistic values D of the other actuators are less than the corresponding threshold values TH-D. In this case, the determination unit3013compares, at S41, the statistic value P with the threshold value TH-P for each of the time sections #9to #12associated with the fixing motor95. When the statistic value P is equal to or larger than the threshold value TH-P in the time sections #9and #10in which the fixing motor95is in an active state, the determination unit3013determines that the abnormal sound is generated. Furthermore, the determination unit3013determines whether or not the statistic value P is less than the threshold value TH-P in the time sections #11and #12in which the fixing motor95is in an inactive state. In other words, it is determined whether or not the abnormal sound stops when the fixing motor95becomes in an inactive state. In a case where an abnormal sound is generated when the fixing motor95is in an active state, and the abnormal sound stops when the fixing motor95becomes in an inactive state, the determination unit3013determines that the fixing unit30driven by the fixing motor95is a candidate unit. Subsequently, the determination unit3013performs the processing from S22to S26, similarly to the first embodiment. Here, it may be configured such that notification is made about, at S24, only the generation of the abnormal sound when the abnormal sound is still generated even when the fixing motor95became in an inactive state.

The present embodiment calculates, for each actuator, the statistic value D based on the difference between the sound wave levels L before and after the change of the state of the actuator, and sets the threshold value TH-D to be larger than the statistic value D. Subsequently, when the statistic value D is newly calculated for each actuator, the statistic value D is compared with the threshold value TH-D firstly to narrow down the actuators that may be related to generation of an abnormal sound. Generation of an abnormal sound is then determined by comparing the statistic value P with the threshold value TH-P for the time section associated with the actuator, similarly to the method of the first embodiment. Here, in a case where an abnormal sound is generated when the actuator is in an active state and no abnormal sound is generated when the actuator is in an inactive state, the replacement unit associated with the actuator is determined to be a candidate unit that may be generating the abnormal sound. The aforementioned configuration allows for determining whether or not an abnormal sound is generated, and determining a candidate unit that may be generating the abnormal sound, even when the abnormal sound is an unknown sound.

Here, the process illustrated inFIG.13narrows down the actuators at S40, and determines generation of an abnormal sound and a candidate unit at S41. However, it may also be configured such that, when there exists an actuator whose statistic value D is equal to or larger than threshold value TH-D at S40, an abnormal sound is determined to be generated, and the unit related to the actuator is determined as a candidate unit. In this case, the processing at S41is skipped.

In addition, the process illustrated inFIG.13, the statistic values (comparison values) D and P for the time section based on the newly acquired sound data are calculated in the methods similar to those for the statistic values D and P used for calculating the threshold values TH-D and TH-P. However, it may be configured such that the comparison values D and P are calculated by a different method from that for the statistic values D and P, similarly to the first embodiment. The comparison value P can be calculated as has been described in the first embodiment, for example. In addition, it is possible to use a different, for example, a smaller number of sound data for calculating the comparison value D compared to the number N of sound data used for calculating the statistic value D which is a base for the threshold value TH-D. Furthermore, the comparison value D may be the mean instead of the percentile value of a plurality of difference values d. Moreover, the comparison value D may be the difference value d calculated from single sound data. In this case, the server SV, upon acquiring single sound data from the image forming apparatus PR, executes the process illustrated inFIG.13.

<Additional Notes>

In each of the aforementioned embodiments, the classification unit3010classifies and groups single sound data based on the difference of operation status of a plurality of actuators for each of a plurality of time sections of the single sound data. However, it may also be configured such that sound data is classified and grouped based on the difference of operation status of each time section of a single actuator. When, for example, the grouping is performed based only on the operation status of the feeding motor91, the sound data illustrated inFIG.6Aand the sound data illustrated inFIG.6Bare grouped in a same group. Alternatively, when the grouping is performed based only on the operation status of the solenoid96, the sound data illustrated inFIG.6Aand the sound data illustrated inFIG.6Bare grouped in different groups. Therefore, the present invention may employ a configuration in which single sound data is classified and grouped based on the difference of the operation status of one or more actuators for each of a plurality of time sections of the single sound data.

Additionally, in each of the aforementioned embodiments, the classification unit3010groups the sound data in a plurality of groups based on the operation status of the actuator. The threshold value setting unit3012then sets the threshold value for each of the plurality of time sections of each of the plurality of groups. Furthermore, the determination unit3013determines whether or not an abnormal sound is generated by calculating a comparison value for each of the plurality of time sections for each of the plurality of groups, and comparing the comparison value for each of the plurality of time sections with the threshold value of the corresponding time section of the same group. However, it may also be configured such that the threshold value setting unit3012sets a threshold value for each of a plurality of time sections for a group among a plurality of groups, and the determination unit3013determines whether or not an abnormal sound is generated by calculating a comparison value based on sound data of the group for which the threshold is set.

It may also be configured such that the process described to be executed by the server SV is executed by the engine control unit87of the image forming apparatus PR. Furthermore, it may also be configured such that a part of the process to be executed by the received sound processing unit70, for example, the process to be performed by the reference value setting unit734and subsequent functional blocks, i.e., the sound data generation process is executed by the server SV. In this case, the image forming apparatus PR transmits the digital signal output from the AD conversion unit733to the server SV together with information indicating the operation status of each actuator.

In addition, the sound diagnosis system according to each of the aforementioned embodiments determines whether or not an abnormal sound is generated in the image forming apparatus PR. However, the sound diagnosis system according to the present invention is not limited to the system that determines whether or not an abnormal sound is generated in the image forming apparatus PR. Specifically, the sound diagnosis system according to the present invention can determine whether or not an abnormal sound is generated in an apparatus including one or more actuators.

OTHER EMBODIMENTS

Embodiment(s) of the present invention can also be realized by a computer of a system or apparatus that reads out and executes computer executable instructions (e.g., one or more programs) recorded on a storage medium (which may also be referred to more fully as a ‘non-transitory computer-readable storage medium’) to perform the functions of one or more of the above-described embodiment(s) and/or that includes one or more circuits (e.g., application specific integrated circuit (ASIC)) for performing the functions of one or more of the above-described embodiment(s), and by a method performed by the computer of the system or apparatus by, for example, reading out and executing the computer executable instructions from the storage medium to perform the functions of one or more of the above-described embodiment(s) and/or controlling the one or more circuits to perform the functions of one or more of the above-described embodiment(s). The computer may comprise one or more processors (e.g., central processing unit (CPU), micro processing unit (MPU)) and may include a network of separate computers or separate processors to read out and execute the computer executable instructions. The computer executable instructions may be provided to the computer, for example, from a network or the storage medium. The storage medium may include, for example, one or more of a hard disk, a random-access memory (RAM), a read only memory (ROM), a storage of distributed computing systems, an optical disk (such as a compact disc (CD), digital versatile disc (DVD), or Blu-ray Disc (BD)™), a flash memory device, a memory card, and the like.

While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.

This application claims the benefit of Japanese Patent Application No. 2022-042776, filed Mar. 17, 2022, which is hereby incorporated by reference herein in its entirety.