JP7031248B2 - Image forming device - Google Patents

Description

The present invention relates to an image forming apparatus.

In general, an image forming apparatus (printer, copier, facsimile, etc.) using electrophotographic process technology irradiates (exposes) a charged photoconductor drum (image carrier) with laser light based on image data. Form an electrostatic latent image. Then, by supplying toner from the developing device to the photoconductor drum on which the electrostatic latent image is formed, the electrostatic latent image is visualized and the toner image is formed. Further, after the toner image is directly or indirectly transferred to the paper, the toner image is formed on the paper by heating and pressurizing with the fixing nip to fix the toner image.

In the image forming apparatus, the durable life of the consumable parts used for image forming is set according to, for example, the number of printed sheets. However, the usage conditions of the image forming apparatus such as the basis weight of the paper used for printing, the coverage of the image formed, the printing speed, the temperature condition, and the pressure such as the fixing nip may differ depending on the user.

For example, the degree of deterioration of consumable parts differs between the case where the printing speed is set to be high and the printing speed is set to low and the printing speed is set to low. .. That is, since the durable life of the consumable parts differs depending on the usage conditions of the user, the consumable parts do not always reach the durable life according to the set durable life.

Therefore, for example, Patent Document 1 discloses a configuration for predicting and determining deterioration of consumable parts due to overuse by determining whether or not the peak value of the volume in the frequency characteristic is larger than a specified value. There is.

Japanese Unexamined Patent Publication No. 2004-226482

However, in the configuration described in Patent Document 1, although the peak value of the volume does not exceed the specified value, the deterioration of consumable parts due to overuse is determined for the high-pitched sound and the abnormal low-pitched sound that are different from the normal operation. Can not do it. That is, the configuration described in Patent Document 1 has a certain limit as a configuration for predicting and determining the durable life of consumable parts.

An object of the present invention is to provide an image forming apparatus capable of accurately predicting the durable life of consumable parts.

The image forming apparatus according to the present invention is
Consumable parts used for predetermined operation and
A frequency acquisition unit that acquires frequency analysis information of the sound generated during operation of the consumable parts, and
A calculation unit that calculates the amount of frequency change between the frequency analysis information acquired by the frequency acquisition unit and the predetermined frequency analysis information.
A prediction unit that predicts the durable life of the consumable parts based on the frequency change amount calculated by the calculation unit.
To prepare for.

According to the present invention, the durable life of consumable parts can be accurately predicted.

It is a figure which shows schematically the whole structure of the image forming apparatus which concerns on embodiment of this invention. It is a figure which shows the main part of the control system of the image forming apparatus which concerns on this embodiment. It is an enlarged view of the fixing part. It is a figure which shows the frequency characteristic in the intensity of a sound. It is a figure for demonstrating the durable life prediction control. It is a figure for demonstrating the durable life prediction control. It is a figure for demonstrating the control which prolongs the predicted endurance life. It is a flowchart which shows the 1st operation example at the time of executing the endurance life prediction determination control in an image forming apparatus. It is a flowchart which shows the 2nd operation example at the time of executing the endurance life prediction determination control in an image forming apparatus.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a diagram schematically showing an overall configuration of an image forming apparatus 1 according to an embodiment of the present invention. FIG. 2 is a diagram showing a main part of the control system of the image forming apparatus 1 according to the present embodiment.

As shown in FIG. 1, the image forming apparatus 1 is an intermediate transfer type color image forming apparatus using an electrophotographic process technique. That is, the image forming apparatus 1 primary transfers the Y (yellow), M (magenta), C (cyan), and K (black) color toner images formed on the photoconductor drum 413 to the intermediate transfer belt 421. After superimposing the toner images of four colors on the intermediate transfer belt 421, the image is formed by secondary transfer to the paper S sent from the paper feed tray units 51a to 51c.

Further, in the image forming apparatus 1, the photoconductor drums 413 corresponding to the four colors of YMCK are arranged in series in the traveling direction of the intermediate transfer belt 421, and the toner images of each color are sequentially transferred to the intermediate transfer belt 421 in one procedure. The tandem method is adopted.

As shown in FIG. 2, the image forming apparatus 1 includes an image reading unit 10, an operation display unit 20, an image processing unit 30, an image forming unit 40, a paper transport unit 50, a fixing unit 60, and a control unit 101.

The control unit 101 includes a CPU (Central Processing Unit) 102, a ROM (Read Only Memory) 103, a RAM (Random Access Memory) 104, and the like. The CPU 102 reads a program according to the processing content from the ROM 103, develops it in the RAM 104, and centrally controls the operation of each block of the image forming apparatus 1 in cooperation with the expanded program. At this time, various data stored in the storage unit 72 are referred to. The storage unit 72 is composed of, for example, a non-volatile semiconductor memory (so-called flash memory) or a hard disk drive.

The control unit 101 transmits / receives various data to / from an external device (for example, a personal computer) connected to a communication network such as a LAN (Local Area Network) or WAN (Wide Area Network) via the communication unit 71. conduct. The control unit 101 receives, for example, image data (input image data) transmitted from an external device, and causes the paper S to form an image based on the image data. The communication unit 71 is composed of a communication control card such as a LAN card.

The control unit 101 acquires the sound collected by the sound collecting member 73, which will be described later, and performs endurance life determination control and endurance life prediction control for the consumable parts of the fixing unit 60 based on the sound. The durable life determination control and the durable life prediction control will be described later.

As shown in FIG. 1, the image reading unit 10 includes an automatic document feeding device 11 called an ADF (Auto Document Feeder), a document image scanning device 12 (scanner), and the like.

The automatic document feeding device 11 conveys the document D placed on the document tray by the conveying mechanism and sends it out to the document image scanning device 12. The automatic document feeding device 11 makes it possible to continuously read a large number of images (including both sides) of documents D placed on the document tray at once.

The document image scanning device 12 optically scans the document conveyed on the contact glass from the automatic document feeding device 11 or the document placed on the contact glass, and the reflected light from the document is a CCD (Charge Coupled Device). ) An image is formed on the light receiving surface of the sensor 12a, and the original image is read. The image reading unit 10 generates input image data based on the reading result of the original image scanning device 12. Predetermined image processing is performed on the input image data by the image processing unit 30.

As shown in FIG. 2, the operation display unit 20 is composed of, for example, a liquid crystal display (LCD: Liquid Crystal Display) with a touch panel, and functions as a display unit 21 and an operation unit 22. The display unit 21 displays various operation screens, image states, operation statuses of each function, and the like according to the display control signal input from the control unit 101. The operation unit 22 includes various operation keys such as a numeric keypad and a start key, receives various input operations by the user, and outputs an operation signal to the control unit 101.

The image processing unit 30 includes a circuit or the like that performs digital image processing according to initial settings or user settings for input image data. For example, the image processing unit 30 performs gradation correction based on the gradation correction data (gradation correction table) under the control of the control unit 101. Further, the image processing unit 30 performs various correction processes such as color correction and shading correction, compression processing, and the like, in addition to gradation correction, on the input image data. The image forming unit 40 is controlled based on the image data subjected to these processes.

As shown in FIG. 1, the image forming unit 40 has image forming units 41Y, 41M, 41C for forming an image with each colored toner of Y component, M component, C component, and K component based on the input image data. , 41K, intermediate transfer unit 42 and the like.

The image forming units 41Y, 41M, 41C, 41K for the Y component, the M component, the C component, and the K component have the same configuration. For convenience of illustration and description, common components are indicated by the same reference numerals, and when distinguishing between them, the reference numerals are given with Y, M, C, or K. In FIG. 1, reference numerals are given only to the components of the image forming unit 41Y for the Y component, and the reference numerals are omitted for the other components of the image forming units 41M, 41C, and 41K.

The image forming unit 41 includes an exposure device 411, a developing device 412, a photoconductor drum 413, a charging device 414, a drum cleaning device 415, and the like.

The photoconductor drum 413 is made of an organic photoconductor in which, for example, a photosensitive layer made of a resin containing an organic photoconductor is formed on an outer peripheral surface of a drum-shaped metal substrate.

The control unit 101 rotates the photoconductor drum 413 at a constant peripheral speed by controlling the drive current supplied to the drive motor (not shown) that rotates the photoconductor drum 413.

The charging device 414 is, for example, a charging charger, and by generating a corona discharge, the surface of the photoconductor drum 413 having photoconductivity is uniformly charged to a negative electrode.

The exposure apparatus 411 is composed of, for example, a semiconductor laser, and irradiates the photoconductor drum 413 with a laser beam corresponding to an image of each color component. As a result, an electrostatic latent image of each color component is formed in the image region irradiated with the laser beam on the surface of the photoconductor drum 413 due to the potential difference from the background region.

The developing device 412 is a two-component reversing type developing device, and a toner image is formed by visualizing an electrostatic latent image by adhering a developer of each color component to the surface of the photoconductor drum 413.

For example, a DC development bias having the same polarity as the charging polarity of the charging device 414 or a development bias in which a DC voltage having the same polarity as the charging polarity of the charging device 414 is superimposed on the AC voltage is applied to the developing device 412. As a result, reverse development is performed in which toner is adhered to the electrostatic latent image formed by the exposure apparatus 411.

The drum cleaning device 415 is in contact with the surface of the photoconductor drum 413, has a flat plate-shaped drum cleaning blade made of an elastic body, and remains on the surface of the photoconductor drum 413 without being transferred to the intermediate transfer belt 421. Remove the toner.

The intermediate transfer unit 42 includes an intermediate transfer belt 421, a primary transfer roller 422, a plurality of support rollers 423, a secondary transfer roller 424, a belt cleaning device 426, and the like.

The intermediate transfer belt 421 is composed of an endless belt and is stretched in a loop on a plurality of support rollers 423. At least one of the plurality of support rollers 423 is composed of a driving roller, and the other is composed of a driven roller. For example, it is preferable that the roller 423A arranged on the downstream side in the belt traveling direction with respect to the primary transfer roller 422 for the K component is the drive roller. This makes it easier to keep the running speed of the belt in the primary transfer unit constant. As the drive roller 423A rotates, the intermediate transfer belt 421 travels at a constant speed in the direction of arrow A.

The intermediate transfer belt 421 is a belt having conductivity and elasticity, and has a high resistance layer on the surface. The intermediate transfer belt 421 is rotationally driven by a control signal from the control unit 101.

The primary transfer roller 422 is arranged on the inner peripheral surface side of the intermediate transfer belt 421 so as to face the photoconductor drum 413 of each color component. The primary transfer roller 422 is pressed against the photoconductor drum 413 with the intermediate transfer belt 421 interposed therebetween, thereby forming a primary transfer nip for transferring the toner image from the photoconductor drum 413 to the intermediate transfer belt 421.

The secondary transfer roller 424 is arranged on the outer peripheral surface side of the intermediate transfer belt 421 so as to face the backup roller 423B arranged on the downstream side of the drive roller 423A in the belt traveling direction. The secondary transfer roller 424 is pressed against the backup roller 423B with the intermediate transfer belt 421 interposed therebetween, thereby forming a secondary transfer nip for transferring the toner image from the intermediate transfer belt 421 to the paper S.

When the intermediate transfer belt 421 passes through the primary transfer nip, the toner image on the photoconductor drum 413 is sequentially superimposed on the intermediate transfer belt 421 and the primary transfer is performed. Specifically, a primary transfer bias is applied to the primary transfer roller 422, and a charge having a polarity opposite to that of the toner is applied to the back surface side of the intermediate transfer belt 421, that is, the side in contact with the primary transfer roller 422. It is electrostatically transferred to the intermediate transfer belt 421.

After that, when the paper S passes through the secondary transfer nip, the toner image on the intermediate transfer belt 421 is secondarily transferred to the paper S. Specifically, a secondary transfer bias is applied to the secondary transfer roller 424 to apply a charge having a polarity opposite to that of the toner on the back surface side of the paper S, that is, the side in contact with the secondary transfer roller 424. Is electrostatically transferred to the paper S. The paper S on which the toner image is transferred is conveyed toward the fixing portion 60.

The belt cleaning device 426 removes the transfer residual toner remaining on the surface of the intermediate transfer belt 421 after the secondary transfer.

The fixing portion 60 is arranged on the fixing surface of the paper S, that is, the upper fixing portion 60A having the fixing surface side member arranged on the surface side on which the toner image is formed, and the back surface of the paper S, that is, on the opposite surface side of the fixing surface. It is provided with a lower fixing portion 60B having a back surface side support member, a heating source, and the like. By pressing the back surface side support member against the fixing surface side member, a fixing nip that sandwiches and conveys the paper S is formed.

The fixing unit 60 secondarily transfers the toner image and heats and pressurizes the conveyed paper S with the fixing nip to fix the toner image on the paper S. The fixing portion 60 is arranged as a unit in the fixing device F.

The upper fixing portion 60A has an endless fixing belt 61, a heating roller 62, and a pad member 64, which are members on the fixing surface side. The fixing belt 61 is stretched by a heating roller 62 and a pad member 64.

The lower fixing portion 60B has a pressure roller 63 which is a back surface side support member. The pressure roller 63 forms a fixing nip that sandwiches and conveys the paper S with the fixing belt 61.

Further, as shown in FIG. 3, a sliding sheet 65 is provided between the fixing belt 61 and the pad member 64. The sliding sheet 65 is a sheet for reducing the frictional resistance between the pad member 64 and the fixing belt 61. As the sliding sheet 65, a glass fiber or the like whose base material has a woven fabric structure is used, and a surface layer coated with a fluorine-based resin such as PTFE is used.

Further, a sound collecting member 73 as an example of the sound collecting unit is provided on the downstream side of the fixing nip in the fixing unit 60. The sound collecting member 73 collects the sound generated in the vicinity of the fixing nip. The sound collected by the sound collecting member 73 is used in the endurance life determination control and the endurance life prediction control described later in the control unit 101.

As shown in FIG. 1, the paper transport unit 50 includes a paper feed unit 51, a paper discharge unit 52, a transport path unit 53, and the like. Paper S (standard paper, special paper) identified based on the basis weight, size, etc. is stored in the three paper feed tray units 51a to 51c constituting the paper feed unit 51 for each preset type. .. The transport path portion 53 has a plurality of transport roller pairs including a resist roller pair 53a. The resist roller portion in which the resist roller pair 53a is arranged corrects the inclination and deviation of the paper S.

The paper S housed in the paper feed tray units 51a to 51c is sent out one by one from the uppermost portion, and is conveyed to the image forming unit 40 by the transfer path unit 53. In the image forming unit 40, the toner image of the intermediate transfer belt 421 is collectively secondarily transferred to one surface of the paper S, and the fixing step is performed in the fixing unit 60. The image-formed paper S is discharged to the outside of the machine by the paper ejection unit 52 provided with the paper ejection roller 52a.

Next, the durability life determination control in the control unit 101 will be described.
In the image forming apparatus 1, the durable life of consumable parts used for a predetermined operation in the fixing unit 60, for example, the sliding sheet 65, is set according to the number of printed sheets and the like. In the following description, the consumable part will be described as the sliding sheet 65.

However, the durable life set for the sliding sheet 65 takes into consideration changes in conditions such as the basis weight of the paper used for printing, the coverage of the image formed, the printing speed, the temperature condition, and the pressure of the fixing nip. do not have.

For example, the first condition for printing thick paper under the condition that the printing speed is set to high speed and the second condition for printing thin paper under the condition that the printing speed is set to low speed are sliding sheets. The degree of deterioration of 65 is different.

Specifically, in the case of the first condition, the printing speed is faster and the pressure at the fixing nip is larger than that of the second condition, so that the surface layer of the sliding sheet 65 is easily worn by the fixing belt 61. As a result, the durable life of the sliding sheet 65 becomes shorter than the second condition. That is, since the durable life of the sliding sheet 65 differs depending on the usage method of the user, the sliding sheet 65 does not always reach the durable life according to the set durable life.

Therefore, the control unit 101 performs frequency analysis of the sound collected by the sound collecting member 73 to acquire frequency analysis information which is a frequency characteristic of the sound indicating the analysis result of the frequency analysis. The control unit 101 reads the predetermined frequency analysis information from the storage unit 72 or the like, calculates the frequency change amount between the frequency analysis information and the predetermined frequency analysis information, and determines the durability state of the sliding sheet 65 based on the frequency change amount. judge. The control unit 101 corresponds to the "calculation unit" and the "determination unit" of the present invention.

The predetermined frequency analysis information indicates, for example, the frequency characteristics of the sound collected by the sound collecting member 73 in the initial state of the sliding sheet 65, and is stored in the storage unit 72 or the like. Specifically, for example, when the sliding sheet 65 is replaced with a new one, the control unit 101 acquires the sound collected by the sound collecting member 73 at the time of initial operation, and performs frequency analysis of the sound. The generated frequency characteristics are stored in the storage unit 72 or the like as predetermined frequency analysis information. The predetermined frequency analysis information may be frequency characteristics or the like obtained in advance by experiments or the like.

Regarding the frequency characteristics of the sound collected during the operation of the sliding sheet 65, for example, as shown by the solid line L1 shown in FIG. 4, in the low frequency band (for example, less than 1 kHz), the sound intensity is the other portion. It has been confirmed that a protruding portion M that protrudes more than the above can be obtained. The protruding portion M corresponds to the "second characteristic portion" of the present invention.

FIG. 4 shows, for example, the frequency characteristics of the sound intensity based on the sound collected while the fixing belt 61 rotates several times when the fixing unit 60 is warmed up, and the frequency characteristics of the sound intensity are shown as each value of the sound intensity. The average value for one rotation of the fixing belt 61 that rotates several times is shown.

The sound intensity is a parameter related to sound, and is, for example, the frequency during operation of the sliding sheet 65, and the loudness and sound pressure of sound generated during operation of the sliding sheet 65.

However, on the other hand, as the durability of the sliding sheet 65 progresses, the sound generated during the operation of the sliding sheet 65 gradually changes. For example, since the sliding sheet 65 in the fixing portion 60 is sandwiched between the fixing belt 61 and the pad member 64, the coating portion on the surface layer of the sliding sheet 65 is worn by the rotation of the fixing belt 61. I will do it. As the sliding sheet 65 wears, the frictional resistance between the sliding sheet 65 and the fixing belt 61 increases, so that the sound generated at the fixing nip portion gradually changes.

As described above, it has been confirmed that the frequency characteristic of the sound in the state where the coating portion on the surface layer of the sliding sheet 65 is worn is as shown by the broken line L2 shown in FIG. The characteristic of the broken line L2 is a frequency characteristic having the same or similar characteristic portion as the solid line L1 as a whole frequency. However, in the low frequency band of the broken line L2, the first protruding portion M1 which is a portion protruding from the other portion of the broken line L2 is located at a position having a different frequency from the protruding portion M in the initial state of the solid line L1. .. The first protruding portion M1 corresponds to the "first feature portion" of the present invention.

That is, the first frequency W1 corresponding to the peak value of the first protruding portion M1 fluctuates with respect to the second frequency W2 corresponding to the peak value of the protruding portion M. FIG. 4 shows an example in which the first frequency W1 fluctuates to a side larger than the second frequency W2.

Further, in the high frequency band (for example, around 10 kHz), in the broken line L2, the second protruding portion M2 in which the sound intensity is higher than the initial state of the solid line L1 appears. As described above, when the coating portion on the surface layer of the sliding sheet 65 is worn, a remarkable difference in the frequency characteristics of sound is shown.

Here, when the durability state is determined by the volume of the sound generated during the operation of the sliding sheet 65, it cannot be determined whether or not the durability life has been reached unless the volume is louder than the preset threshold value. there is a possibility. That is, although the peak value of the volume does not exceed the threshold value, it is not possible to determine the deterioration of the sliding sheet 65 due to overuse for high-pitched sounds and abnormal low-pitched sounds that are different from those during normal operation.

For example, when the sliding sheet 65 reaches the end of its durable life and is damaged, a loud sound is generated, and the intensity of the sound in the high frequency band varies such that the second protrusion M2 is generated. In such a case, it is considered possible to determine the deterioration of the sliding sheet 65, for example, by monitoring the average value of the volume of the entire frequency characteristic.

However, as the deterioration of the sliding sheet 65 progresses, the frequency corresponding to the peak value tends to fluctuate in the low frequency band, but the average value of the volume of the entire frequency characteristic is the second protrusion M2. It is considered that it does not fluctuate so much unless Therefore, in such a case, it may not be possible to determine the deterioration of the sliding sheet 65 based on the volume, but by monitoring such frequency fluctuations, it is possible to accurately recognize the durability state of the sliding sheet 65. It is considered possible.

Therefore, in the present embodiment, since the durability state of the sliding sheet 65 is determined based on the amount of frequency change between the frequency analysis information and the predetermined frequency analysis information, the sound generated during the operation of the sliding sheet 65 is recorded. It is possible to accurately recognize the change and, by extension, accurately determine the durability state of the sliding sheet 65.

Specifically, the control unit 101 calculates the difference between the first frequency W1 and the second frequency W2 as the amount of frequency change, and when the difference is a predetermined frequency (for example, 100 Hz) or more, the sliding sheet 65 Judged as having a durable life. The predetermined frequency is, for example, a value indicating the amount of change in frequency from the new state of the sliding sheet 65 to the state where the sliding sheet 65 has reached the endurance life or is extremely close to the endurance life, and is a value appropriately set by experiments, simulations, or the like. Is.

Further, the control unit 101 may determine that the sliding sheet 65 has a durable life when there is a change in sound intensity in the high frequency band between the frequency analysis information and the predetermined frequency analysis information. ..

Next, the durable life prediction control in the control unit 101 will be described.
As described above, since the change in the sound of the sliding sheet 65 can be accurately recognized by the amount of frequency change, the control unit 101 predicts the durable life of the sliding sheet 65 based on the amount of frequency change. The control unit 101 corresponds to the "prediction unit" of the present invention.

Specifically, as shown in FIG. 5, the control unit 101 determines the frequency change amount when the drive time of the sliding sheet 65 is T1 and the frequency change amount when the drive time is T2 longer than T1. It is calculated, and the drive time for the frequency change amount to reach a predetermined frequency V0 is predicted from these frequency change amounts.

For example, when the frequency change amount when the drive time is T1 is 0 and the frequency change amount when the drive time is T2 is V1, the vertical axis is the frequency change amount and the horizontal axis is the drive time. , Plot the frequency change of each drive time. Then, the control unit 101 forms an extension line E1 of a straight line passing through these two points, and T3, which is the drive time when the extension line E1 intersects the predetermined frequency V0, is the time for the sliding sheet 65 to reach the endurance life. Predict.

The amount of frequency change when the drive time is T1 is stored in, for example, in the storage unit 72 as history information of frequency analysis information when the drive time is T1. Then, when the control unit 101 calculates the frequency change amount when the drive time is T2, the control unit 101 reads out the frequency change amount when the drive time is T1 from the storage unit 72, thereby performing the above-mentioned durability life prediction control.

By doing so, the durable life of the sliding sheet 65 can be easily predicted, so that the sliding sheet 65 can be used up to the correct durable life. In addition, since it becomes easier to determine the guideline for parts replacement in the sliding sheet 65, the number of times the serviceman for maintaining the image forming apparatus 1 performs the parts replacement work can be reduced, and unnecessary parts replacement can be suppressed. As a result, the cost of replacing parts can be reduced.

Note that FIG. 5 illustrates a case where the frequency change amount is a positive value, that is, the frequency corresponding to the peak value fluctuates to the larger side as the durability progresses, but the peak value becomes as the durability progresses. The corresponding frequency may fluctuate to the smaller side. Therefore, the predetermined frequency is set to −V0 on the negative side in addition to V0 on the positive side. Further, as an example in which the frequency change amount becomes a negative value, if a frequency change amount having the same absolute value as the positive side is obtained, the linear curve on the positive side (including the extension line E1) is in the negative side region. A linear straight line D1 that behaves as if it is inverted is formed. Then, it is predicted that the time at the intersection of the primary straight line D1 and −V0, which is a predetermined frequency on the negative side, is the time to reach the durable life of the sliding sheet 65.

Further, in FIG. 5, the durable life of the sliding sheet 65 was predicted only by the two frequency changes when the driving times were T1 and T2, but the sliding sheet 65 was predicted by using three or more frequency changes. You may predict the endurance life of.

FIG. 6 shows a plot of a total of eight frequency changes, in which the drive time is between T1 and T2, and six frequency changes are added. The eight frequency change amounts in FIG. 6 are within the range between 0, which is the frequency change amount when the drive time is T1, and V2, which is the frequency change amount when the drive time is T2. The control unit 101 forms an extension curve E2 which is an extension of the approximate curves of these eight frequency changes, and sets T4, which is the drive time when the extension curve E2 and the predetermined frequency V0 intersect, with the sliding sheet 65. Is predicted to be the endurance life.

By doing so, the same effect as the example shown in FIG. 5 can be obtained, and the accuracy of predicting the durable life of the sliding sheet 65 can be improved as compared with the example shown in FIG. Also in FIG. 6, a predetermined frequency −V0 is set on the negative side as in FIG. Further, as an example in which the frequency change amount becomes a negative value, if a frequency change amount having an absolute value similar to that on the positive side is obtained, a curve on the positive side (including an extension curve E2) is provided in the negative region. A curve D2 showing an inverted behavior is formed. Then, the time related to the intersection of the curve D2 and −V0, which is a predetermined frequency on the negative side, is predicted to be the time to reach the durable life of the sliding sheet 65.

Further, the control unit 101 may determine whether or not the durable life of the sliding sheet 65 is longer than the predicted durable life according to the predicted durable life.

In the initial setting of the image forming apparatus 1, from the viewpoint of improving productivity, the transport speed of the paper S is set to be relatively high, but the number of parts replacement is reduced and the parts are replaced before the parts are replaced. In some cases, such as when it takes time, the durability of consumable parts is important. In such a case, the control unit 101 determines that the durable life of the sliding sheet 65 is longer than the predicted durable life.

In FIG. 7, when the frequency change amount reaches V2, the control unit 101 controls so that the durable life of the sliding sheet 65 becomes longer than the predicted durable life, for example, the transport speed of the paper S is slowed down. do. The control unit 101 forms a prediction curve E3 such that the amount of frequency change with respect to time is smaller than the extension curve E2 of the approximation curve, and newly predicts T5, which is the drive time at which the prediction curve E3 intersects the predetermined frequency V0. It has a durable life.

As a result, the predicted endurance life of the sliding sheet 65 can be extended, so that the time of the predicted endurance life can be adjusted according to the situation. Further, this control may be performed automatically when the amount of frequency change reaches an arbitrary value such as V2, or the user may be allowed to select either productivity or durability. When the user is made to select this control, for example, an alarm may be output, such as displaying an operation unit or the like to select either one or generating an alarm or the like.

As an example in which the frequency change amount in FIG. 7 becomes a negative value, if a frequency change amount having an absolute value similar to that on the positive side is obtained, a curve on the positive side (extension curve E2) is provided in the negative region. Included), curves D3 and D4 showing behavior as if E3 was inverted are formed. Then, the time related to the intersection of the curves D3 and D4 and −V0, which is a predetermined frequency on the negative side, becomes the predicted endurance life of the sliding sheet 65 depending on the situation.

Next, a first operation example when executing the durability life prediction determination control in the image forming apparatus 1 will be described. FIG. 8 is a flowchart showing a first operation example when the durable life prediction determination control in the image forming apparatus 1 is executed. The process in FIG. 8 is premised on the process from the time when the sliding sheet 65 is replaced until the sliding sheet 65 reaches the endurance life.

As shown in FIG. 8, the control unit 101 acquires frequency analysis information in the initial state of the sliding sheet 65 (step S101). Specifically, the control unit 101 acquires frequency analysis information by acquiring the sound generated from the fixing unit 60 during the warm-up operation and performing frequency analysis of the sound.

Next, the control unit 101 stores the acquired frequency analysis information in the storage unit 72 as predetermined frequency analysis information (step S102). Next, the control unit 101 starts the operation in the image forming apparatus 1 (step S103).

Next, the control unit 101 acquires the sound generated from the fixing unit 60 and performs frequency analysis of the sound to acquire frequency analysis information (step S104). Examples of the timing for acquiring the frequency analysis information in step S104 include the timing at which the paper S is not positioned on the fixing nip, such as before or after the paper S reaches the fixing nip in the print job. Further, the control unit 101 may acquire the frequency analysis information at the timing of once every several sheets during the print job, or may acquire the frequency analysis information for each sheet.

Next, the control unit 101 calculates a frequency change amount which is a difference between the acquired frequency analysis information and the predetermined frequency analysis information stored in the storage unit 72, and the frequency change amount is equal to or larger than the absolute value of the predetermined frequency V0. It is determined whether or not the frequency is (step S105).

As a result of the determination, when the frequency change amount is smaller than the absolute value of the predetermined frequency V0 (step S105, NO), the control unit 101 determines whether or not to calculate the predicted endurance life (step S106).

If the predicted endurance life is not calculated as a result of the determination (step S106, NO), the process returns to step S104. For example, when the durability of the sliding sheet 65 is not so advanced, or when the predicted durability life is calculated and the time has not elapsed so much, it is determined that the predicted durability life is not calculated.

On the other hand, when calculating the predicted endurance life (step S106, YES), the control unit 101 calculates the predicted endurance life (step S107). As a method for calculating the predicted durable life, the methods shown in FIGS. 5 and 6 are used. It should be noted that the process of step S107 may be performed at all times without performing the process of step S106.

Next, the control unit 101 performs control so as to notify the predicted endurance life to the outside (step S108). Examples of the control include a control for notifying an external organization that manages maintenance of the image forming apparatus 1 via a communication unit 71 or the like to notify the predicted endurance life. After step S108, the process returns to step S104.

Returning to the determination in step S105, when the amount of frequency change is equal to or greater than the absolute value of the predetermined frequency V0 (step S105, YES), the control unit 101 displays on the display unit 21 and the like that the sliding sheet 65 has a durable life. (Step S109). After that, this control ends.

Next, a second operation example when the durable life prediction determination control in the image forming apparatus 1 is executed will be described. FIG. 9 is a flowchart showing a second operation example when the durable life prediction determination control in the image forming apparatus 1 is executed. The process in FIG. 9 is premised on the process from the time when the sliding sheet 65 is replaced until the sliding sheet 65 reaches the endurance life.

As shown in FIG. 9, the control unit 101 acquires frequency analysis information in the initial state of the sliding sheet 65 (step S201). The acquisition of frequency analysis information is the same as in step S101 of FIG.

Next, the control unit 101 stores the acquired frequency analysis information in the storage unit 72 as predetermined frequency analysis information (step S202). Next, the control unit 101 starts the operation in the image forming apparatus 1 (step S203).

Next, the control unit 101 acquires the sound generated from the fixing unit 60 and performs frequency analysis of the sound to acquire frequency analysis information (step S204). The timing for acquiring the frequency analysis information is the same as in step S104 of FIG.

Next, the control unit 101 calculates a frequency change amount which is a difference between the acquired frequency analysis information and the predetermined frequency analysis information stored in the storage unit 72, and the frequency change amount is shown, for example, in FIG. It is determined whether or not it is equal to or greater than the absolute value of V2 (step S205).

As a result of the determination, when the frequency change amount is smaller than the absolute value of V2 (step S205, NO), the process proceeds to step S209. On the other hand, when the frequency change amount is equal to or greater than the absolute value of V2 (step S205, YES), the control unit 101 determines whether or not the frequency change amount is equal to or greater than the absolute value of the predetermined frequency V0 (step S206).

As a result of the determination, when the frequency change amount is smaller than the absolute value of the predetermined frequency V0 (step S206, NO), the control unit 101 determines whether or not to extend the predicted endurance life (step S207). The determination in step S207 may be determined based on the operation instruction of the user, or may be determined based on the setting of the image forming apparatus 1.

As a result of the determination, when it is determined that the predicted endurance life is not lengthened (step S207, NO), the process proceeds to step S209. On the other hand, when it is determined that the predicted endurance life is to be extended (step S207, YES), the control unit 101 controls to slow down the conveying speed of the paper S (step S208). In step S208, any control may be performed as long as the control can extend the durable life of the sliding sheet 65.

Next, the control unit 101 determines whether or not to calculate the predicted endurance life (step S209). If the predicted endurance life is not calculated as a result of the determination (step S209, NO), the process returns to step S204.

On the other hand, when calculating the predicted endurance life (step S209, YES), the control unit 101 calculates the predicted endurance life (step S210). As a method for calculating the predicted durable life, the methods shown in FIGS. 5 and 6 are used. It should be noted that the process of step S210 may be performed at all times without performing the process of step S209.

Next, the control unit 101 performs control so as to notify the predicted endurance life to the outside (step S211). The control is the same as in step S108 of FIG. After step S211 the process returns to step S204.

Returning to the determination in step S206, when the amount of frequency change is equal to or greater than the absolute value of the predetermined frequency V0 (step S206, YES), the control unit 101 displays on the display unit 21 and the like that the sliding sheet 65 has a durable life. (Step S212). After that, this control ends.

According to the present embodiment as described above, the durability state of the sliding sheet 65 is determined based on the amount of frequency change between the frequency analysis information and the predetermined frequency analysis information. Therefore, it is possible to accurately recognize the change in the sound generated during the operation of the sliding sheet 65, and to accurately determine the durability state of the sliding sheet 65.

Further, since the durable life of the sliding sheet 65 is predicted based on the amount of frequency change between the frequency analysis information and the predetermined frequency analysis information, the durable life of the sliding sheet 65 can be easily predicted, and eventually the sliding sheet 65 can be easily predicted. The moving sheet 65 can be used for the correct durable life.

Further, since the durability state of the sliding sheet 65 is determined and predicted based on the amount of frequency change between the frequency analysis information and the predetermined frequency analysis information, the durability state of the sliding sheet 65 can be accurately determined even if it is a consumable part having a surface layer. Can be determined and predicted.

In addition, since it becomes easier to determine the guideline for parts replacement in the sliding sheet 65, the number of times the serviceman for maintaining the image forming apparatus 1 performs the parts replacement work can be reduced, and unnecessary parts replacement can be suppressed. As a result, the cost of replacing parts can be reduced.

In the above embodiment, the control unit 101 performs frequency analysis of the sound collected by the sound collecting member 73, but the present invention is not limited to this and has a CPU different from that of the control unit 101. The control unit 101 may acquire the frequency analysis information analyzed by the frequency analysis unit. Further, the control unit 101 may acquire the frequency analysis information analyzed by the frequency analysis unit outside the image forming apparatus 1.

Further, in the above embodiment, the sound collecting member 73 is located on the downstream side of the fixing nip in the fixing portion 60, but the present invention is not limited to this, and for example, the sound collecting member 73 may be located on the upstream side of the fixing nip. good.

Further, in the above embodiment, the sound collecting member 73 is provided in the image forming apparatus 1, but the present invention is not limited to this, and the sound collecting member 73 may not be provided in the image forming apparatus 1. In this case, the control unit 101, the frequency analysis unit, or the like may acquire sound information from the sound collecting member located outside the image forming apparatus 1.

Further, in the above embodiment, the sliding sheet 65 is exemplified as a consumable part, but the present invention is not limited to this, for example, other than the sliding sheet 65 such as the fixing belt 61 and the pressure roller 63 in the fixing portion 60. It may be a part of. Further, the consumable parts may be parts in the image forming unit 41, parts in the intermediate transfer unit 42, and the like.

Further, in the above embodiment, as the first feature portion, the first frequency W1, that is, the peak value of the sound intensity in the frequency analysis information is exemplified, and as the second feature portion, the second frequency W2, that is, a predetermined frequency. Although the peak value of the sound intensity in the analysis information is exemplified, the present invention is not limited to this. For example, when a characteristic part in the frequency characteristic waveform is detected other than the peak value of the sound intensity, the first characteristic part and the second characteristic part are set to a part other than the peak value of the frequency characteristic waveform. May be.

Further, in the above embodiment, the frequency characteristics in the initial state are exemplified as the predetermined frequency analysis information, but the present invention is not limited to this, and for example, the history information of the frequency characteristics stored in the storage unit 72 or the like. The frequency characteristic selected from among them may be used as predetermined frequency analysis information. For example, when the power of the image forming apparatus 1 is turned on, the history information when the power was turned on last time may be used as the predetermined frequency analysis information.

In addition, the above embodiments are merely examples of embodiment of the present invention, and the technical scope of the present invention should not be construed in a limited manner by these. That is, the present invention can be implemented in various forms without departing from its gist or its main features.

1 Image forming device 60 Fixing part 61 Fixing belt 62 Heating roller 63 Pressurizing roller 64 Pad member 65 Sliding sheet 72 Storage unit 73 Sound collecting member 101 Control unit

Claims (8)

Consumable parts used for predetermined operation and
A frequency acquisition unit that acquires frequency analysis information of the sound generated during operation of the consumable parts, and
A calculation unit that calculates the amount of frequency change between the frequency analysis information acquired by the frequency acquisition unit and the predetermined frequency analysis information, and a calculation unit.
A prediction unit that predicts the durable life of the consumable parts based on the frequency change amount calculated by the calculation unit.
An image forming apparatus. A control unit for determining whether or not the durable life of the consumable part is longer than the predicted durable life according to the predicted durable life predicted by the predicted unit is provided.
The image forming apparatus according to claim 1 . The calculation unit has a first frequency corresponding to the first characteristic portion of the parameter related to the sound in the frequency analysis information and a second frequency corresponding to the second characteristic portion of the parameter related to the sound in the predetermined frequency analysis information. Calculate the difference,
The image forming apparatus according to claim 1 or 2 . The first characteristic portion is a peak value of a parameter related to the sound in the frequency analysis information.
The second characteristic portion is the peak value of the parameter related to the sound in the frequency analysis information.
The image forming apparatus according to claim 3 . A storage unit for storing the history information of the frequency analysis information is provided.
The calculation unit calculates the frequency change amount by using the history information stored in the storage unit as the predetermined frequency analysis information.
The image forming apparatus according to any one of claims 1 to 4 . The calculation unit calculates the frequency change amount by using the frequency analysis information in the initial state of the consumable parts as the predetermined frequency analysis information.
The image forming apparatus according to any one of claims 1 to 5 . It is provided with a frequency analysis unit that acquires a sound generated during operation of the consumable part and analyzes the frequency of the sound.
The image forming apparatus according to any one of claims 1 to 6 . A sound collecting unit for collecting sounds generated during operation of the consumable parts is provided.
The image forming apparatus according to any one of claims 1 to 7 .

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