JP2021039267A - Life determination device, life determination method, and life determination program - Google Patents

Abstract

To provide a life determination device, a life determination method, and a life determination program that can determine the life of an image forming member with high accuracy satisfying a quality request from a user.SOLUTION: A life determination device comprises: a setting unit that is used to determine whether an image forming member used for image formation has reached the end of its life, and sets a threshold of a related parameter related to the occurrence of an image defect based on a real image determined by a user as an image defect; and a life determination unit that determines whether the image forming member has reached the end of its life based on a measured value and the threshold of the related parameter related to an image obtained through image formation.SELECTED DRAWING: Figure 5

Description

The present invention relates to a life determination device, a life determination method, and a life determination program.

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.

Further, in an image forming apparatus, it is required to always output an image of a quality satisfying the user, but in general, the image output on paper is gradually but inevitably deteriorated due to the durability of parts and the like. It has the property of going on. For this reason, it is necessary to regularly perform quality inspection of the image output on the paper, investigation of the cause when the image quality deteriorates, and maintenance work such as replacement and cleaning of parts. A service person to do it visits the user on a regular basis.

Further, in the image forming apparatus, the quality of the image output on the paper is inspected, and processing such as presence / absence of image defects, diagnosis of parts causing image defects, and life prediction are performed. Some models are equipped with a life prediction device (see, for example, Patent Document 1).

In an image forming apparatus of such a model, various image forming members related to image forming inside the apparatus (hereinafter, for the sake of simplicity) occur regularly or when an image defect (also referred to as a defective image, an abnormal image, etc.) occurs. Performs diagnostic mode processing for diagnosing failures, defects, durability, etc. of (simply referred to as "parts").

In this diagnostic mode, for example, parts are based on various data such as the mode of image defect (type, feature amount, etc.) and past usage history (number of prints, time when each part is replaced, etc.) in the image forming apparatus. Failure diagnosis and prediction of parts replacement time (life, that is, end of durability). Here, regarding whether or not the replacement time (life) of a part has arrived, it is determined by using various methods such as machine learning whether or not the actual amount of the part actually used has reached a predetermined “life threshold”. (presume.

Regarding this, in Patent Document 1, in order to more accurately predict the part to be replaced and the timing, the degree of image defect and the part that caused the image defect are specified from the difference between the master image and the output image, and the relevant part is specified. Techniques for estimating the life of parts are described.

JP-A-2015-34807

By the way, in many conventional life prediction devices or diagnostic modes, an inspection image (test chart) in which the color and shape of the output toner image are predetermined is output on paper, and the predetermined image is read. The diagnosis (analysis, etc.) was performed on the presence or absence of defective images.

As another example, in the technique of Cited Document 1, the master image based on the input image data is compared with the inspection target image actually printed and read on the paper, and it is abnormal when there are pixels having different pixel values. It is determined that there is an image (image defect) (see paragraph 0032, etc.).

On the other hand, the required quality of the output image of the image forming apparatus actually differs for each individual user. For example, a user who outputs a lot of low print rate images such as characters tends not to be concerned even if some white streaks appear, but on the other hand, a user who outputs a lot of high print rate images such as photographs and figures. Often judges that there is a problem with quality even with a small amount of white streaks.

In view of the above situation, in the conventional configuration in which the life of parts is uniformly determined (estimated) using the threshold value determined by the developer of the image forming apparatus, the following is used for many users. Problems are likely to occur.

In other words, for users who often output many images with low print rates, parts that should still be usable will be replaced or cleaned at the stage of image defects at a level that is not yet noticeable, which is unnecessary. Problems such as reduced printing productivity and higher costs due to the occurrence of waiting time occur.

On the other hand, for users who output many images with a high printing rate, image defects often occur before parts are replaced, and printing work cannot be performed until a serviceman is called after the occurrence of waste paper and a response is made. , The problem of more waiting time and reduced productivity occurs.

In addition, regardless of the required quality of the image, if a serviceman visits the user and maintenance work such as parts replacement due to failure or wear or cleaning of defective parts occurs, printing work cannot be performed during that time. There is a user disadvantage of reduced productivity.

For this reason, conventionally, the configuration has been such that the presence or absence of image defects is diagnosed based on a strict standard (threshold value) required by a user who outputs many images with a high printing rate. However, when such a strict standard (threshold value) is used, for users with low demand for image quality, parts that can still be used sufficiently are replaced, in other words, maintenance work that is less necessary is performed. Therefore, disadvantages such as a decrease in productivity occur.

Regarding the threshold value that serves as a reference for the presence or absence of image defects, Patent Document 1 proposes a configuration that can be arbitrarily set by the user in advance for each type of abnormal image (image defect). However, the technique described in Patent Document 1 has a problem that the burden on the user side at the threshold setting stage becomes excessive, and the details of such a problem will be described later.

In general, according to the prior art, the timing of parts replacement tends to deviate from the situation in which the user is actually using the image forming apparatus, and the difference in the user's requirements for image quality and changes in the requirements, etc. There were various problems such as inability to operate flexibly in response to the above.

An object of the present invention is to provide a life determination device, a life determination method, and a life determination program capable of determining the life of an image forming member with high accuracy corresponding to a user's quality requirements and the like.

The life determination device according to the present invention is
It is used to determine whether the image forming member used for image formation has reached the end of its life, and the threshold value of the related parameter related to the occurrence of image defect is based on the actual image judged to be image defect by the user. And the setting part to set
A life determination unit that determines whether or not the image forming member has reached the end of its life based on the actually measured values of the related parameters related to the image formed and the threshold value.
To be equipped.

The life determination method according to the present invention is
It is used to determine whether the image forming member used for image formation has reached the end of its life, and the threshold value of the related parameter related to the occurrence of image defect is based on the actual image judged to be image defect by the user. Set and set
It is determined whether or not the image forming member has reached the end of its life based on the actually measured values of the related parameters related to the image formed and the threshold value.

The life determination program according to the present invention is
On the computer
It is used to determine whether the image forming member used for image formation has reached the end of its life, and the threshold value of the related parameter related to the occurrence of image defect is based on the actual image judged to be image defect by the user. And the process to set
A process of determining whether or not the image forming member has reached the end of its life based on the actually measured values of the related parameters and the threshold value of the image formed.
To execute.

According to the present invention, the life of the image forming member can be determined with high accuracy corresponding to the user's quality requirements and the like.

It is a figure which shows schematic the whole structure of the image forming apparatus in this embodiment. It is a block diagram which shows the main part of the control system in the image forming apparatus of FIG. It is a flowchart which shows the flow of processing in a normal diagnostic mode. It is a table explaining an example which classifies and stores an image defect. It is a flowchart which shows an example of the process of setting or updating the user threshold value (threshold value of a related parameter) used in the diagnostic mode of this embodiment. It is a flowchart for demonstrating the outline of the process flow in the diagnostic mode of this embodiment.

Hereinafter, embodiments of the image forming apparatus 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 shows a main part of the control system of the image forming apparatus 1 in the present embodiment.

The image forming apparatus 1 shown in FIGS. 1 and 2 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 toner image is formed by secondary transfer to the paper S.

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 conveying unit 50, a fixing unit 60, an output image reading unit 80, and a control unit. It is equipped with 100 and the like.

The control unit 100 includes a CPU (Central Processing Unit) 101, a ROM (Read Only Memory) 102, a RAM (Random Access Memory) 103, and the like. The CPU 101 reads a program according to the processing content from the ROM 102, develops it in the RAM 103, 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.

In the present embodiment, the control unit 100 also plays a main role as the "lifetime determination device" of the present invention, and the method for determining the lifespan and the like will be described later.

The control unit 100 transmits and receives various data to and 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. Do. The control unit 100 receives, for example, image data transmitted from an external device, and causes the paper S to form a toner image based on the image data (input image data).

The communication unit 71 is composed of a communication control card such as a LAN card. In the present embodiment, the communication unit 71 functions as a "transmission unit" that transmits various diagnostic results and data described later by the control unit 100 to an external device such as a server.

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 can continuously read a large number of images (including both sides) of the 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 scanning result by the original image scanning device 12. The image processing unit 30 performs predetermined image processing on the input image data.

The operation display unit 20 is composed of, for example, a liquid crystal display (LCD) with a touch panel, and functions as a display unit 21 and an operation unit 22. The display unit 21 displays various operation screens, an image status display, an operation status of each function, and the like according to a display control signal input from the control unit 100. 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 100.

The image processing unit 30 includes a circuit or the like that performs digital image processing according to initial settings or user settings on the input image data. For example, the image processing unit 30 performs gradation correction based on the gradation correction data (gradation correction table LUT) in the storage unit 72 under the control of the control unit 100. Details of such gradation correction processing will be described later. 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.

The image forming unit 40 is an image forming unit 41Y, 41M, 41C, 41K, and an intermediate transfer unit 42 for forming an image with each colored toner of Y component, M component, C component, and K component based on the input image data. Etc. are provided.

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 they are distinguished from each other, they are indicated by adding Y, M, C, or K to the reference numerals. In FIG. 1, the 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 has, for example, an undercoat layer (UCL: Under Coat Layer), a charge generation layer (CGL: Charge Generation Layer), and a charge transport layer (CGL) on the peripheral surface of a conductive cylindrical body (aluminum tube) made of aluminum. It is a negatively charged organic photo-conductor (OPC) in which CTL: Charge Transport Layer) is sequentially laminated. The charge generation layer is made of an organic semiconductor in which a charge generation material (for example, a phthalocyanine pigment) is dispersed in a resin binder (for example, polycarbonate), and a pair of positive charges and negative charges are generated by exposure by an exposure apparatus 411. The charge transport layer is composed of a hole transport material (electron donating nitrogen-containing compound) dispersed in a resin binder (for example, polycarbonate resin), and transports positive charges generated in the charge generation layer to the surface of the charge transport layer. To do.

The control unit 100 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 uniformly charges the surface of the photoconductor drum 413 having photoconductivity to a negative electrode property. 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. Positive charges are generated in the charge generation layer of the photoconductor drum 413 and transported to the surface of the charge transport layer, so that the surface charge (negative charge) of the photoconductor drum 413 is neutralized. An electrostatic latent image of each color component is formed on the surface of the photoconductor drum 413 due to the potential difference from the surroundings.

The developing device 412 is, for example, a developing device of a two-component developing method, and forms a toner image by visualizing an electrostatic latent image by adhering toner of each color component to the surface of the photoconductor drum 413.

The drum cleaning device 415 has a drum cleaning blade or the like that is in sliding contact with the surface of the photoconductor drum 413, and removes the transfer residual toner remaining on the surface of the photoconductor drum 413 after the primary transfer.

The intermediate transfer unit 42 includes an intermediate transfer belt 421 as an image carrier, 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 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. By pressing the primary transfer roller 422 against the photoconductor drum 413 with the intermediate transfer belt 421 sandwiched between them, a primary transfer nip for transferring the toner image from the photoconductor drum 413 to the intermediate transfer belt 421 is formed.

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. By pressing the secondary transfer roller 424 against the backup roller 423B with the intermediate transfer belt 421 sandwiched between them, a secondary transfer nip for transferring the toner image from the intermediate transfer belt 421 to the paper S is formed.

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 opposite to that of the toner is applied to the back surface side (the side that abuts the primary transfer roller 422) of the intermediate transfer belt 421 to obtain a toner image. 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 toner image is obtained by applying a secondary transfer bias to the secondary transfer roller 424 and applying a charge having a polarity opposite to that of the toner on the back surface side of the paper S (the side that comes into 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 has a belt cleaning blade or the like that is in sliding contact with the surface of the intermediate transfer belt 421, and removes the transfer residual toner remaining on the surface of the intermediate transfer belt 421 after the secondary transfer.

The fixing portion 60 is on the upper fixing portion 60A having a fixing surface side member arranged on the fixing surface (the surface on which the toner image is formed) side of the paper S, and on the back surface (opposite surface of the fixing surface) side of the paper S. It includes a lower fixing portion 60B having a back surface side support member to be arranged, a heating source 60C, and the like. By pressing the back surface side support member against the fixing surface side member, a fixing nip that narrowly holds and conveys the paper S is formed.

The fixing unit 60 fixes the toner image on the paper S by secondarily transferring the toner image and heating and pressurizing the conveyed paper S with the fixing nip. The fixing unit 60 is arranged as a unit in the fixing device F. Further, the fuser F is provided with an air separation unit 60D that separates the paper S from the fixing surface side member by blowing air.

The paper transport unit 50 includes a paper feed unit 51, a paper discharge unit 52, a transport path unit 53, and the like. The three paper feed tray units 51a to 51c constituting the paper feed unit 51 accommodate the paper S (standard paper, special paper) identified based on the basis weight, size, etc. for each preset type. .. The transport path portion 53 has a plurality of transport roller pairs such as a resist roller pair 53a.

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. At this time, the resist roller portion in which the resist roller pair 53a is arranged corrects the inclination of the fed paper S and adjusts the transfer timing. Then, 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.

The output image reading unit 80 reads an image (toner image) output (formed) on the paper S as an image carrier. In the present embodiment, the output image reading unit 80 receives a plurality of light emitting elements (for example, an infrared LED array that emits infrared light) as a light emitting unit that emits light, and a light receiving light that receives the reflected light of the light. It is an optical sensor including a light receiving element (for example, a photodiode) as a unit.

The output image reading unit 80 operates based on the control signal of the control unit 100, and outputs an image (toner image) formed on the paper to the control unit 100 as read image data.

In the present embodiment, the output image reading unit 80 is arranged downstream of the fixing unit 60 and upstream of the paper ejection unit 52. The output image reading unit 80 is arranged so that the plurality of infrared LED arrays are located in the width direction (direction orthogonal to the transport direction) of the paper S.

The output image reading unit 80 irradiates the image-formed paper S with infrared light from each infrared LED array, receives the reflected light with a photodiode, and receives the received light amount (of the image on the paper S). The electric signal corresponding to the density) is A / D converted and output to the control unit 100 as read image data.

In the present embodiment, the output image reading unit 80 is the actual image on the paper S on which the image of the print job is printed (output or formed) by the image forming apparatus 1, or the test chart output (printed) on the paper S. Is read, and the data of the read image is output to the control unit 100.

Here, the "actual image" on the paper S means an image that the user outputs as a printed matter (manuscript, delivery, etc.) at the time of actual printing (actual printing), and the paper at the time of image inspection (diagnosis mode) described later. The explanation will be made separately from the test chart (inspection image) output (printed) to S.

(Diagnosis mode processing)
By the way, while the image forming apparatus 1 is required to output an image of a quality that the user is satisfied with, the image output on the paper is gradually but inevitably deteriorated due to the durability of the parts and the like. It has the property of going on. For this reason, it is necessary to periodically diagnose the presence or absence of image defects in the toner image output on the paper, and the identification of parts that cause the image defects.

The control unit 100 of the image forming apparatus 1 of the present embodiment inspects the image quality of the toner image, defective parts, and the like based on the reading result of the output image reading unit 80 provided in the own machine as described above. Predict the life of replaceable parts, determine whether they have reached the end of their life, etc.) on a regular basis. Hereinafter, this diagnosis will be referred to as a "diagnosis mode".

In the present embodiment, the control unit 100 mainly corresponds to the "lifetime determination device" of the present invention, and the output image reading unit 80 also forms a part of such a lifespan determination device.

That is, the control unit 100 functions as an "analysis unit" that analyzes the type and degree of deterioration of the image read by the output image reading unit 80, and is a consumable component (image forming) used for image forming in the image forming apparatus 1. It also functions as a "prediction unit" that predicts the life of the member).

Further, in correspondence with the present invention, the control unit 100 functions as a "life determination unit" for determining whether or not the image forming member has reached the end of its life, and a "setting unit" described later. In addition, the control unit 100 also functions as a "specific unit" that identifies an image forming member that causes the image defect when an image defect occurs in the image formed.

Hereinafter, with reference to FIG. 3, an outline of processing in a normal diagnostic mode according to the prior art, which is executed by the image forming apparatus 1 of the present embodiment, will be described.

For example, when a predetermined button of the operation unit 22 is selected by the user, the control unit 100 of the image forming apparatus 1 shifts to the diagnostic mode and forms a predetermined inspection image (test chart) on the paper S. Each part is controlled so as to be (printed) (step S101).

In one specific example, the inspection image is a strip-shaped halftone image (or solid image) classified by each toner color (Y, M, C, K). The image data for such inspection is stored in the storage unit 72 in advance. In the following, in order to distinguish from the above-mentioned "real image", the image for inspection is simply referred to as "inspection image".

At this time, the control unit 100 reads the image data of the inspection image from the storage unit 72, develops it in a work area such as the RAM 103, and prints the inspection image on the paper S, so that the image processing unit 30 and the image forming unit 30 40, the paper transport unit 50, the fixing unit 60, and the like are controlled. At this time, the control unit 100 operates the output image reading unit 80 to cause the output image reading unit 80 to read the inspection image on the paper S.

Subsequently, the control unit 100 acquires inspection image data (density information) from the output image reading unit 80, and temporarily stores the acquired data in a memory (RAM 103 or the like) (step S102).

Further, the control unit 100 analyzes the image (here, the inspection image) on the paper S read by the output image reading unit 80 based on the function of the “analysis unit”, and is read by the output image reading unit 80. It is determined whether the inspection image on the paper S is normal (whether there is an image defect) (step S103).

In one specific example, in this analysis and determination, the image data of the inspection image developed in the work area as described above is regarded as a so-called "correct image", and the density (density distribution) of the correct image and the inspection on the paper S are performed. Image reading This is performed by specifying the difference (density difference) from the density (density distribution) of the image.

As the correct image of the inspection image, in addition to the case where the image expanded in the RAM 103 is directly used, the output image reading unit 80 is made to read the sample image in which the inspection image is already printed (printed recording medium). The scanned image may be used.

Here, when the control unit 100 determines that the inspection image on the paper S is normal and there is no image defect (step S103, YES), the control unit 100 proceeds to step S104. On the other hand, when the control unit 100 determines that the inspection image on the paper S has an image defect (step S103, NO), the control unit 100 proceeds to step S106.

In step S104 after determining that there is no image defect, the control unit 100 obtains usage condition information (usage amount up to now, current temperature / humidity information, etc.) of the image forming member (part) to be diagnosed. , Update for each part to be diagnosed. Then, the control unit 100 predicts the life of each component by using the updated information (step S105).

In this life prediction, among the parts constituting the image forming apparatus 1, the part (here, the image forming member used for image forming) to be the target of the life prediction is the usage amount (actual use) at which the life (use limit) is reached. The amount) is defined for each part as a "life threshold", and the time when these parts reach the life threshold is predicted. Then, the control unit 100 determines whether or not each of the parts to be predicted has reached the end of its life based on whether or not the predicted time has been reached.

Further, the control unit 100 is used to eliminate the transition of image deterioration in the future, the type of image defect that may occur first, and the image defect based on the above-mentioned usage condition information and the analysis result of the density difference. By identifying the parts that need to be replaced, the time when the parts reach the life threshold is predicted.

The contents of the usage condition information and the like will be described later as appropriate.

On the other hand, in step S106, the control unit 100 identifies the type of image defect that has occurred.

Here, a specific example of a method for identifying the type of image defect by the control unit 100 will be described with reference to FIG. FIG. 4 shows an example of classifying the types of image defects when a rectangular image defect (so-called noise image) occurs in the inspection image read by the output image reading unit 80.

In the example shown in FIG. 4, the control unit 100 identifies (classifies) into any one of "pot", "vertical streak", "horizontal streak", and "band" according to the size of the rectangular image defective portion. Specifically, when the length (width) of the defective image portion along the transport direction (paper-passing direction) and the length (width) in the direction orthogonal to the paper-passing direction are both less than 1 mm, the control unit 100 is used. , The defective part of the image is specified as "Pochi".

On the other hand, when the length of the defective image portion is less than 1 mm and the width is 1 mm or more, it is specified as a "horizontal streak", and conversely, when the length of the defective image portion is 1 mm or more and the width is less than 1 mm. Is identified as a "vertical streak". Further, when the length and width of the defective image portion are both 1 mm or more, it is classified as a "band", and when the width is longer than the length, it is a "horizontal band", and the width is larger than the length. If it is short, it is identified as a "vertical band".

In addition, the control unit 100 also identifies (classifies) the color of the type of image defect described above. That is, when the defective image portion is an image missing (so-called white spot), the control unit 100 specifies it as "white spot", "white vertical streak", "white horizontal streak", and "white band". On the other hand, when the defective image portion is a noise image of a specific color, the control unit 100 specifies it as a "color spot", a "color vertical streak", a "color horizontal streak", and a "color band".

When the defective image portion has an irregular shape other than a rectangle, the control unit 100 classifies (specifies the type) the defective image as "density unevenness".

In the following step S107, the control unit 100 specifies the degree (level) of image defects, in other words, the degree or level (grade) of image deterioration.

For example, when white streaks occur in the paper passing direction, the control unit 100 generates streaks (in this case, white vertical streaks) based on the density difference between the density of the image defect occurrence portion and the density of the peripheral portion. In addition to the presence or absence, the degree of streaks (grade, etc.) can be specified.

When a plurality of types of image defect portions are generated in step S106, the control unit 100 specifies the degree of image defect for each type specified in the previous step in step S107.

Further, the control unit 100 updates the usage condition information (usage history) of the consumable part (image shape member) to be diagnosed for each part in the same manner as in step S104 described above (step S108).

Here, the usage condition information (usage history) includes, for example, the usage amount of the part (operating time, paper transport distance, total number of prints, etc.), change in the physical property value of the part (for example, transition of resistance value, etc.). ) And usage conditions (average temperature and humidity, average number of prints per day, etc.).

Then, the control unit 100 uses various information such as the type and degree of the image defect specified in steps S106 and S107, the usage condition information updated in step S108, and the like, and causes the defect that caused the image defect. The component is specified (step S109).

For example, if foreign matter such as dust is caught in the blade (regulatory part) of the developing apparatus 412 (see FIG. 1) and vertical streaks are generated, even if the vertical streaks are thin and thin at the beginning of the image defect, the foreign matter is present. Since it grows larger due to the adhesion of toner, it gradually becomes darker and wider as vertical stripes according to the number of sheets to be passed.

On the other hand, as an example of the life threshold value of the blade (regulatory unit), the values of "width" and "concentration" that the above-mentioned vertical streaks can be visually recognized (or conspicuous) are registered. The specific values of the width and the concentration are determined exclusively from the viewpoint of the manufacturer or the serviceman.

Thus, the control unit 100 refers to the life threshold set for each of the parts to be diagnosed, refers to the diagnosis result in the diagnosis mode executed in the past, and further repeatedly executes the processes of steps S101 to S108 as appropriate. By doing so, it is possible to identify defective parts.

In other words, the process of identifying the defective component in step S109 is a process of identifying or determining (discriminating) a component that has reached the end of its useful life among various components (image forming members) used for image forming.

Then, in step S110, the control unit 100 communicates with an external server or the like through the communication unit 71 to indicate that an image defect has occurred, the type and degree of the image defect that has occurred, and the specified defective component (in this example, the defective component). The process of notifying the serviceman of the blade), etc. is performed.

In the above case, the cause of the image defect (that is, the defective part) is relatively easy to understand, and depending on the mode of the image defect, it may be difficult to identify the defective part or narrow down to one. Even in such a case, by notifying the service person of information such as the type and degree of image defects, it can be used as an effective clue for identifying defective parts.

Thus, in the normal diagnostic mode in the image forming apparatus 1, a test inspection image in which the shape of the toner image and the like are predetermined is output on the paper S, and the inspection image is read to check for the presence or absence of defective images and defective parts. , Diagnose (analyze, judge, etc.) the life of each part.

By the way, the usage (printing) of the image forming apparatus 1 and the quality required for the output image differ depending on each user. For example, user A who prints full-color photo data on thick paper or coated paper mainly for producing photo books and pamphlets, and black text (character data) on plain paper or backing paper mainly for manuscript creation. The quality required for the output image is significantly different from that of User B, who prints a large amount every day.

That is, as a general tendency, the user A has a higher level of quality required for the output image than the user B. Further, when printing is frequently used like User B, there is a high tendency to dislike the occurrence of so-called waiting time during which the image forming apparatus 1 cannot be used due to a failure, maintenance, or the like.

Furthermore, even if the same image forming apparatus 1 is used by the user A and the user B, if the printing purpose as described above and the type and frequency of the output paper are significantly different, the image forming apparatus 1 is consumed or malfunctions. Parts that are easy to use also tend to be different.

Based on this situation, as explained in FIG. 3, a relatively simple (so-called standardized) inspection image is used, and a threshold value related to image defect is set and executed from the viewpoint of the serviceman. It has been found that normal diagnostic modes do not always give good results.

Further, for example, in the technique described in Patent Document 1, the presence or absence of an abnormal image (image defect) is determined by comparing the master image based on the input image data with the inspection target image actually printed and read on the paper. I try to do it (see paragraph 0032, etc.). In addition, in the technique described in Patent Document 1, it is proposed that the threshold value can be arbitrarily set by the user in advance for each type of abnormal image (image defect).

However, the technique described in Patent Document 1 has a problem that the burden on the user side at the threshold setting stage becomes excessive as described below.

Specifically, when the image forming apparatus is new when the threshold value is set, image defects rarely occur from the initial stage. Therefore, according to the technique described in Patent Document 1, there are many users. It is necessary to compare the sample images of the above, select a sample that does not meet the required quality, and set a corresponding threshold value.

However, as described above, the threshold setting for image defects based on the sample image is burdensome for the user when setting for each type of image defect (vertical streaks, horizontal streaks, spots, bands, unevenness, etc.). It becomes excessive. In addition, setting the threshold value for image defects based on the sample image tends to cause deviation from the actual defective image that will occur in the future, and it is difficult to flexibly respond to changes in the quality required by the user. , There is a problem.

In general, it is difficult to set a threshold value that matches the image quality desired by the user at the initial stage of bringing in the image forming apparatus, which is unlikely to cause image defects, and at the stage when an unacceptable image defect of the user actually occurs. It is considered that setting the threshold value is more practical and less wasteful.

Further, at the timing when the image deterioration occurs to the extent that the user who sees the output of the image forming apparatus 1 feels that "this is about time for maintenance of the apparatus", the part causing the image deterioration is a serviceman. It is thought that a mechanism to be notified to is should be built.

In view of the above circumstances, the image forming apparatus 1 in the present embodiment inspects the diagnosis target in the diagnosis mode, that is, the "real image", that is, the image printed as the output or the delivery in the actual print job. Use as an alternative to or additionally for images.

Further, in the present embodiment, the image forming member used for image forming determines the value of the image deterioration degree of the actual image at the time when the user actually feels that "unacceptable image deterioration has occurred". It is set as an image defect threshold value related to the life threshold of the usage amount that becomes the life.

Here, the image defect threshold value corresponds to the "threshold value of the related parameter" of the present invention, and is used to determine whether or not the image forming member used for image forming has reached the end of its life. Further, the related parameter is a parameter related to the occurrence of image defects, and in the present embodiment, "difference in density in the image" is used.

In correspondence with the present invention, the operation display unit 20 and the control unit 100 play the role of a "setting unit" for setting the above-mentioned image defect threshold value (threshold value of related parameters).

Then, the control unit 100 uses the set image defect threshold value to identify the image forming member that caused the image defect, and to determine whether or not the image forming member has reached the end of its life. Further, a process of predicting the time when another image forming member reaches the life threshold, and the like are performed.

As an actual operation example, in the initial carry-in stage in which the image forming apparatus 1 is exclusively operating normally, a general threshold value for image defects is defined by the manufacturer side or the serviceman side of the image forming apparatus 1. A standard (hereinafter, this threshold value is referred to as "inspection threshold value") is used.

On the other hand, when the durability of the image forming apparatus 1 is advanced, or when dust enters the inside of the apparatus even at the initial carry-in stage and an image defect (that is, unacceptable image deterioration) occurs for the user, the above-mentioned The image defect threshold value for each user is set using the setting unit. Hereinafter, this image defect threshold value set for each user from the viewpoint of the user of the image forming apparatus 1 will be referred to as a “user threshold value”.

Such a user threshold can be set, for example, by updating or rewriting the inspection threshold as a general reference described above. On the other hand, since such a setting operation is complicated for a general user, the serviceman performs an input operation of the above-mentioned setting unit (for example, the setting screen of the diagnostic mode displayed on the display unit 21) for the user threshold value. It is good to set. Then, after the user threshold value is set, the control unit 100 uses the currently set user threshold value as a criterion for determining the presence or absence of an image defect in the diagnostic mode (see step S103 in FIG. 3).

Thus, in the present embodiment, the judgment on the image defect according to the preference and the actual situation of each user is reflected in the diagnosis of the parts, and at the time when the image deterioration to the extent that "maintenance may be required soon" occurs. Build a mechanism for notifying service personnel.

By constructing a mechanism based on such a concept, for example, it becomes easier to identify that consumable parts according to the actual printing conditions of each user are the cause of image defects, and as a result, for any user, The waiting time associated with the occurrence of maintenance work can be reduced, and printing productivity can be improved.

That is, a user who has a strict demand for image quality can minimize the time required to stop the printing work due to the occurrence of an image defect, and can further improve the printing productivity. On the other hand, for users with low (loose) image quality requirements, cost reduction can be achieved by using consumable parts to the extent that they are close to the durability limit, and the number of maintenances per fixed period is reduced. , Printing productivity can be increased.

Further, in the present embodiment, the threshold values related to the presence or absence of image defects are set as the inspection threshold value (so to speak, the first threshold value) defined from the viewpoint of the manufacturer or the serviceman, and the viewpoint of the user (required quality, etc.). It was decided to use two user threshold values (so to speak, a second threshold value) defined (set) based on the above. Then, the user threshold value (second threshold value) among them corresponds to the "threshold value of the related parameter" of the present invention.

Further, in the present embodiment, when the user threshold value (second threshold value) is updated, the value of each user threshold value set before the update is also used (added) instead of simply rewriting the previous user threshold value. Generate and update a new user threshold.

With the above configuration, even if the user's request for image quality changes after the user threshold is set, it is possible to flexibly deal with the update of the user threshold, the processing of the diagnostic mode, and the like.

Hereinafter, the flow of processing in the diagnostic mode in the present embodiment based on the above-mentioned concept will be described with reference to the flowcharts of FIGS. 5 and 6. The same processing as that of the flowchart of FIG. 3 described above will be appropriately assigned the same or similar step numbers, and the description thereof will be omitted.

First, the process of generating or updating (accumulating) the user threshold (second threshold) defined by the required quality on the user side is shown in the flowchart of FIG. The routine shown in FIG. 5 can be automatically started, for example, when a print job is executed after the total number of prints and the total usage time exceed a predetermined amount. Alternatively, the routine shown in FIG. 5 can be executed by a user who feels that the quality of the output image of the print job by the image forming apparatus 1 has deteriorated through the operation of the setting screen of the diagnostic mode.

In step S101A, the control unit 100 controls each of the above-described units of the image forming apparatus 1 so as to start the printing operation and output the input image of the print job to the paper S. This printing operation itself is the same as the case of executing a normal print job.

Note that step S101A and subsequent step S102A correspond to step S101 and step S102 described above in FIG. 3, and at this time, the control unit 100 is formed on the paper S by operating the output image reading unit 80. The output image reading unit 80 is made to read an actual image (an image based on the input image data of the print job).

Subsequently, the control unit 100 acquires the data of the actual image from the output image reading unit 80, and temporarily stores the acquired data in a memory (RAM 103 or the like) (step S102A).

Further, the control unit 100 determines whether or not it is pointed out that an image defect has occurred during the execution of the print job (step S13). The control unit 100 determines whether or not such an indication is made based on whether or not a predetermined switch (for example, a switch displayed on the display unit 21 for pointing out "an unacceptable image defect occurrence") is selected by the user. ..

Here, when the control unit 100 determines that no image defect has occurred during the execution of the print job (step S13, NO), the control unit 100 ends the print job and ends the routine. The control unit 100 can execute the processes of steps S104 and S105 described above in FIG. 3 until the print job is completed.

On the other hand, when the control unit 100 determines that an image defect has occurred during the execution of the print job (steps S13, YES), the control unit 100 proceeds to step S16. At this time, the control unit 100 can temporarily stop or suspend (end) the print job arbitrarily or according to the user setting.

In step S16, the control unit 100 specifies the type and degree of image defects in the actual image. This process is the same as the process of step S106 and step S107 described above in FIG.

In step S17, the control unit 100 generates or updates a user threshold value (second threshold value) for each type of image defect for each type of image defect specified in the previous step. Here, the user threshold value (second threshold value) can be generated as a new threshold value by rewriting the existing standard threshold value (first threshold value) in the specified image defect type.

On the other hand, when updating the already set user threshold value (second threshold value), the control unit 100 changes the existing user threshold value (second threshold value) in the specified image defect type. Here, in the present embodiment, when updating the user threshold value (second threshold value), the past user threshold value (second threshold value) is saved without being deleted.

Then, in the present embodiment, when the user threshold value is updated from the existing value in step S17, the control unit 100 weights and updates the value specified in step S16. In other words, the control unit 100 sets (updates) the user threshold value (threshold value of the related parameter) by weighting the actual image determined to be image defect later than the actual image determined to be image defect earlier by the user. That is, reset).

As a result, the user threshold value is updated (corrected) so as to flexibly respond to changes in the user's senses, values, etc., and the user threshold value before the update (second threshold value, that is, the image defect threshold value) and the user threshold value after the update (the second threshold value, that is, the image defect threshold value) The life of a component (image forming member) can be predicted by using the image defect threshold value.

Subsequently, the control unit 100 performs the processes of steps S108 to S110 described above in FIG. 3 to end this routine. In step S110, in addition to the above-mentioned information, the control unit 100 sets the data of the entire image on the paper pointed out by the user and the image defect occurs, and the value of the generated or updated user threshold value (second threshold value). Also notify the serviceman.

By performing the process of identifying defective parts (step S109) using the user threshold value (second threshold value) generated as described above or all user threshold values (second threshold value) generated and updated in the past, more It is possible to identify defective parts accurately and according to the actual situation.

Further, by additionally notifying the serviceman of the entire image pointed out by the user or the value of the generated or updated user threshold value (second threshold value) (step S110), the serviceman can, for example, be a defective part. It can be useful for narrowing down the exchange target when there are multiple candidates.

In the example shown in FIG. 5, a flow in which the user threshold value (second threshold value) is automatically generated or updated in step S17 has been described. As another processing example or setting example, the processing of step S17 in the flowchart of FIG. 5 may be suspended or skipped, and the user threshold value (second threshold value) may be manually set or updated. In this case, the serviceman who visits the user after the notification in step S110 may set or update the user threshold value (second threshold value) after listening to the user's judgment, the request for image quality, and the like.

Next, the processing of the diagnostic mode executed after the user threshold value (second threshold value, that is, the threshold value of the related parameter) is set or accumulated to some extent will be described with reference to the flowchart of FIG.

The flow chart shown in FIG. 6 can be processed at the time of executing a normal print job, or may be performed periodically or at an arbitrary time by a setting operation through the operation display unit 20 of the user.

In step S1, the control unit 100 controls each of the above-described units of the image forming apparatus 1 so as to start the printing operation. This printing operation itself is the same as the case of executing a normal print job.

Note that step S1 and subsequent step S2 correspond to step S101 and step S102 described above in FIG. That is, the control unit 100 operates the output image reading unit 80 to cause the output image reading unit 80 to read the toner image (actual image based on the input image data) formed on the paper S.

Subsequently, the control unit 100 acquires the actual image data (measured value) for one page (one sheet of paper) from the output image reading unit 80, and temporarily stores the acquired image data in the work area of the RAM 103. At the same time, the density analysis of the image data is performed (step S2).

Next, the control unit 100 determines whether the image for one page read and actually measured by the output image reading unit 80 is normal, that is, deterioration of the actual image and generation of noise images and the like (hereinafter collectively referred to as "actual image". The presence or absence of (referred to as "abnormality") is determined (step S3).

In one specific example, the control unit 100 compares the density analysis of the actual image in step S2 with the density value of the corresponding portion of the input image stored in the RAM or the like when the print job is executed, and compares the density value of the corresponding portion. When the difference is equal to or greater than the inspection threshold value, it is determined that there is an abnormality in the actual image (step S3, YES).

The threshold value regarding the presence / absence of abnormality in the actual image here may be set to a value equivalent to the case of the determination of “presence / absence of image defect” in step S103 described above in FIG. In one specific example, the threshold value for determining the presence or absence of abnormality in the actual image in step S3 can be set based on whether or not there is deterioration or noise image that exceeds the variation in the error of the output image reading unit 80.

In general, the threshold value for determining the presence or absence of abnormality in the actual image should be set based on the user who has the highest (strict) demand for image quality. In other words, at this point, the user threshold value (second threshold value), that is, the judgment standard according to the user's preference and the like is not applied, and the uniform judgment standard (first threshold value) is applied.

Here, when the control unit 100 determines that the density difference within one page is not equal to or greater than the inspection threshold value (step S3, NO), it determines that the actual image for one page is normal, and steps S4 to step S4 to step 100. S11 is skipped and the process proceeds to step S12. On the other hand, when the control unit 100 determines that the density difference within one page is equal to or greater than the inspection threshold value (step S3, YES), the control unit 100 determines that there is an abnormality in the actual image for one page, and proceeds to step S4.

In step S4, the control unit 100 classifies the shape of the abnormal image portion (hereinafter, referred to as “abnormal image portion”) on the paper S. The process of step S4 is the same as the identification or classification of the type of image defect in step S106 described in FIG. 3, and the control unit 100 has streaks (vertical streaks, horizontal streaks), white spots, color spots, bands, and so on. Identify or identify color unevenness, etc.

In the following step S5, the control unit 100 specifies the degree or level (concentration difference in this example) of the abnormal image unit (that is, image deterioration) for each shape (that is, type) classified (specified) in the previous step. , Each shape and the corresponding density difference are stored in the storage unit 72. By such processing, for example, the size of the actually generated streaks (length and width), the detailed size of the color spots and the white spots, and the like are specified and stored. The control unit 100 stores the specific result in a database in the storage unit 72 (see FIG. 4 as appropriate).

Note that step S6 and subsequent step S7 correspond to step S108 and step S109 described above in FIG. First, the control unit 100 updates the "use condition information" of the image forming apparatus 1 (user) for each image forming member (part) to be diagnosed (step S6). This usage condition information is information (data) stored (stored) in a memory (storage unit 72, etc.) of the image forming apparatus 1, and corresponds to the "usage history" of the present invention.

Here, the "use condition information" includes the use information of the image forming member (part) to be diagnosed. This usage information includes the actual usage amount of the component (number of times of use, usage time, etc.), transition of physical properties of the component (change in resistance value, etc.), image formation conditions at the time of printing by the image forming apparatus 1, and the like. Here, the "image forming conditions" include, for example, the temperature and humidity around the image forming apparatus 1 (that is, inside and outside the machine), the number of prints per unit time (for example, the average number of prints per day), and one print job. The total number of prints in. It should be noted that this is an example, and various other information can be used depending on the type of parts and the like.

Then, the control unit 100 uses various information such as the type and degree of the abnormal image unit (in other words, the image defect) identified in steps S4 and S5, the usage condition information updated in step S5, and the like. The defective part (image forming member) that caused the abnormal occurrence of the image is identified (step S7).

In the following step S8, the control unit 100 determines whether or not there is an image defect in one page of the paper S on which the actual image is printed by the same method as in step S3 described above. However, as the threshold value regarding the presence or absence of image defects here, the user threshold value (second threshold value), that is, the image defect threshold value to which the judgment criteria according to the user's preference and the like are applied is used.

In one specific example of step S8, the control unit 100 determines the actual image (measured value of density) analyzed in density in step S2 and the density value of the corresponding portion of the input image stored in the RAM or the like when the print job is executed. Is compared to determine whether or not the density difference at the corresponding portion is equal to or greater than the image defect threshold value (that is, the user threshold value as the second threshold value).

Therefore, the image defect threshold value (user threshold value, second threshold value) is set to a value equivalent to the inspection threshold value (first threshold value) for users seeking high quality, and a value looser than the inspection threshold value (first threshold value). Even if the specific result of step S7 is the same as that of the user set to, the determination result of step S8 may be different.

Then, when the control unit 100 determines that the density difference within one page is equal to or greater than the image defect threshold value (step S8, YES), there is an image defect that the user cannot tolerate, and the defective component identified in step S7 has a lifetime. It is determined that the threshold value has been reached, and the process proceeds to step S9.

On the other hand, when the control unit 100 determines that the density difference within one page is not equal to or greater than the image defect threshold value (step S8, NO), the generated abnormal image unit is not an image defect but a level that the user can tolerate. It is determined that the defective part identified in S7 has not reached the life threshold value, and the process proceeds to step S11.

In step S9, the control unit 100 is connected to an external server or the like through the communication unit 71 in the same manner as in step S110 described in FIG. Performs processing to notify the service person of defective parts, etc.

Further, in the following step S10, the control unit 100 notifies the serviceman that an image defect has occurred, the type and degree of the image defect that has occurred, the identified defective part, and the like, and the like. Is displayed on the display screen of the operation display unit 20 to notify the user, and the process proceeds to step S12.

On the other hand, in step S11, the control unit 100 uses the information condition information of the component unit updated in step S6 as in step S105 described in FIG. 3, and the defective component (image forming member) identified in step S7. ) Is predicted, and then the process proceeds to step S12.

In the life prediction process in step S11, the control unit 100 can appropriately correct the life threshold value of the defective component specified in step S7. Further, the control unit 100 may appropriately correct the life threshold value of other image-forming members in accordance with the correction of the life threshold value of the defective component.

Further, in the life prediction process in step S11, the control unit 100 transmits, for example, the defective component identified in step S7 and the life period predicted for the defective component to an external device such as a server via the communication unit 71. Or you may notify the service person.

By such processing, the parts that cause the image deterioration are released before the image deterioration occurs to the extent that the user who sees the output of the image forming apparatus 1 feels that "this may require maintenance of the device". Since the serviceman is notified, it is convenient for the user and the serviceman.

Thus, the control unit 100 corrects each life threshold value of the plurality of (N pieces) parts (image forming members) using the image defect threshold value set based on the user's judgment, and each part is corrected. The life of individual parts is predicted by estimating the time until the life threshold is reached.

In step S12, the control unit 100 determines whether or not the print job has been completed, and if it is determined that the print job has been completed (YES in step S12), the control unit 100 ends this routine. On the other hand, when the control unit 100 determines that the print job has not been completed yet (step S12, NO), the control unit 100 returns to step S1 to start the printing operation on the next paper S, and performs the operations up to step S12 described above. Execute repeatedly.

In the present embodiment, in step S11 above, the control unit 100 focuses on predicting the life of the image-forming member identified as a defective part in step S7.

For example, in steps S4 and S5 described above, it is specified that "color spots" are generated, and in step S7, "secondary transfer roller 424" is specified as one of the candidates for the cause of such color spots. Suppose the case that was done.

Generally, the secondary transfer roller 424 has a property that its resistance value changes according to the temperature and humidity in the machine and the number of prints in the daytime. Therefore, image defects such as color spots caused by an increase in the resistance of the secondary transfer roller 424 may change in the deterioration transition of the image defects depending on the usage conditions of the image forming apparatus 1.

In such a case, in addition to the transition of the image defect of the actual image, the control unit 100 obtains the user's usage conditions and the usage information of the secondary transfer roller 424 (in this case, the transition of the resistance value, etc.) described in step S6. By referring to it, it is possible to predict the life of parts more accurately.

(Accumulation of user threshold for image defects)
For example, image defects may occur due to irregular causes that are not related to the life of parts, such as dust adhering during actual use. In such a case, it is usually necessary for a service person to visit and clean the inside of the image forming apparatus 1. By storing the information of the output image before cleaning at this time, the user threshold value for determining that the image is defective is accumulated. More specifically, information is accumulated for various image defects such as white streaks, color streaks, white spots, black spots, and uneven density.

The user threshold information may be stored in a recording medium (for example, a USB memory) via the above-mentioned communication unit 71 of the image forming apparatus 1 or an input / output interface (for example, a USB connector). With such a configuration, even when a machine (image forming apparatus) is replaced or additionally purchased, this information (user threshold value) is transferred to a new machine and the threshold value as before is set ( Can be taken over).

Alternatively, when one user is using a plurality of image forming devices at the same time through a network such as a LAN, the user threshold value is stored in the network server, for example, so that the user threshold value can be set in each image forming device. You can also share it.

(Correction method when changing the user threshold)
Depending on the circumstances of the user, for example, when the required quality of the operator or the reader of the printed matter changes, it is necessary to change the user threshold value of the image defect, that is, the boundary value for determining that the user has the image defect.

When changing the user threshold as described above, it is advisable to weight the user so that the latest judgment of the user can be prioritized. With such a setting, the user threshold value can be corrected so as to flexibly correspond to changes in the user's senses, values, and the like. As a result, it is possible to perform lifespan prediction or lifespan determination that reflects the latest feelings of the user.

In one specific example, the control unit 100 displays a user threshold input screen for setting or updating the user threshold on the display unit. This user threshold input screen can input (set) a user threshold for each type of image defect (white streaks, color streaks, ..., Etc.) described above.

Then, the serviceman inputs and sets a new user threshold value on the user threshold value input screen every time the boundary value for determining that the user has an image defect changes. At this time, the control unit 100 does not simply change (update to replace) the previous user threshold value with a new user threshold value, but weights the latest user threshold value to the previous user threshold value to the latest user threshold value. Update to a value between the user thresholds that is closer to the latest user threshold.

By performing the above-mentioned update process, it is possible to perform life prediction and life judgment that reflect the latest user feeling without discarding all the user feelings for image defects up to that point.

(Identification of defective parts that cause image defects)
In order to identify (estimate) the parts that cause image defects and predict the replacement time of the parts (hereinafter also referred to as "defective parts"), it is not enough to analyze the actual image output by the user. In some cases, it may be better to output and analyze a specific inspection image (test chart, etc.) as described above.

In that case, when a serviceman visits the residence of the user in which the image forming apparatus 1 is installed for a regular visit or the like, in the processing of the diagnostic mode of the present embodiment described above in FIG. 6, based on the operation of the serviceman, The inspection image is set to be printed on the paper S. In this case, the control unit 100 causes the output image reading unit 80 to read the inspection image (test chart, etc.) output on the paper S, and the type and degree of image defects (deterioration) that occur in the read inspection image. Is analyzed (step S2). By performing such processing, the control unit 100 can more easily identify the defective component that causes the image defect in step S7.

Therefore, a serviceman who visits the user's place of residence can easily identify or estimate a part that is nearing the end of its life, which causes an unacceptable image defect for the user. As a result, it is possible to determine the time and cost of the next visit to the user's place at an early stage, and it is possible to reduce the waiting time of the user.

In one specific example, when a streak occurs during printing of an actual image (step S4), the control unit 100 occurs in all the colors C, M, Y, and K, or occurs in a single color. By determining whether or not the component is defective, it is possible to identify defective parts to some extent without outputting an inspection image or the like. On the other hand, when streaks occur during printing of the actual image (step S4), it becomes difficult to identify defective parts when the user outputs only the actual image of mixed colors.

In the above case, the serviceman outputs an inspection image composed of C, M, Y, and K monochromatic charts, and the output image is analyzed by the control unit 100 to detect defective parts that cause image defects. It can be identified more clearly (or the candidates for defective parts are narrowed down).

Specifically, when the control unit 100 has streaks on the charts of all colors C, M, Y, and K in the inspection image, the defective part is the secondary transfer roller 424 or the intermediate transfer belt 421. It can be judged that the possibility is high.

On the other hand, in the control unit 100, when the streaks of the inspection image appear only in any one of C, M, Y, and K, the defective parts are the photoconductor drum 413, the charging device 414, the exposure device 411, and the developing. It can be determined that there is a high possibility that it is a component on the primary transfer side such as the device 412.

In addition, the control unit 100 uses the above-mentioned usage history (driving time, physical property transition, humidity and temperature, number of prints during the day, cleaning of each part of the serviceman) stored in the memory (storage unit 72, etc.). By referring to or adding to the work contents such as, etc.), it becomes easier to identify defective parts.

(Forecasting the life of specific parts)
As described above, the control unit 100 predicts the life of the specified defective part after identifying the defective part in step S7 (step S11).

At this time, the control unit 100 can predict the life of the defective part from the transition of the image defect and the usage condition of the user, but by considering the transition of the physical properties of the defective part, the life of the defective part can be predicted more accurately. can do.

As a specific example, consider a case where it is determined that an image defect (white streak) has occurred by image analysis of the control unit 100, and then the blade of the developing device is identified as a defective component. Here, in general, in order to predict the life of a blade, not only the average CW (Contact Width) of the blade edge and the usage environment (temperature, humidity, etc.), but also various as shown in the following formula 1. Factors need to be considered.
[Formula 1]
Blade life prediction value = _{(a 1} × average CW) + _{(a 2} × use environment) + _{(a 3} × monthly print number) + _{(a 4} × idling _{time) + ···· + (a n ×} ○○ ) + B ₁

In the above formula 1, a indicates an arbitrary coefficient, n as a subscript of the coefficient a indicates the total number of factors serving as explanatory factors, and b ₁ indicates an offset value. Further, it is shown that the larger the blade life predicted value, the closer to the above-mentioned "life threshold".

Each explanatory factor in Equation 1 corresponds to the "caused parameter" of the present invention and also corresponds to the "use history of the image forming member and / or the image forming condition". More specifically, the "average CW", "monthly number of prints", and "idle rotation time" correspond to the "amount of image forming member used" of the present invention. In addition, the "monthly number of prints" corresponds to the "number of prints within a predetermined time" of the present invention. Further, the "use environment" corresponds to the "temperature and humidity" of the present invention.

In general, the predicted life value of the blade, and thus the predicted life value of each component that becomes an image forming member, _{increases as the explanatory factor (number of n} ) increases, and increases as the value of the coefficient a is set larger, and further. It can be seen that the larger the offset value b _{1, the larger the value.}

Then, in the present embodiment, the control unit 100 uses the above-mentioned user threshold value (image defect threshold value) in the life prediction of defective parts (step S11), and the image output from the image forming apparatus 1 is equal to or larger than the user threshold value. The predicted time (timing) is specified as the life of the defective part, that is, the time when the life threshold is reached.

In the example of Equation 1 described above, that is, in the case where the defective part is identified as the blade of the developing device, the control unit 100 uses the user threshold value set for the white streaks, and the user whose blade life predicted value is applied. The time (timing) to reach the life threshold corresponding to the threshold is calculated.

Thus, in one specific example of the present embodiment, as illustrated in Equation 1, the relationship of the life prediction value (objective variable or dependent variable) with respect to a plurality (n) explanatory factors (explanatory variable or independent variable) is defined. (Clarification of causal relationship). Then, the control unit 100 determines the life prediction value of the consumable part in consideration of the result of the multivariate analysis in which the replacement time of the consumable part is set as the objective variable and the plurality of usage information up to the replacement is set as the explanatory variable.

Preferably, the control unit 100 corrects the predicted life value by performing multivariate analysis of the information of each factor up to the replacement of the component and the timing of the actual replacement.

As described in detail above, according to the present embodiment, the parts (image forming members) that should be replaced or will be replaced in the near future according to the quality requirements of the user of the image forming apparatus 1 and the like. More accurate prediction (life judgment, etc.) can be performed for the specified and the specified part.

From another aspect, according to the present embodiment, the result of life prediction at an appropriate time according to the image quality requirement of the user of the image forming apparatus 1 can be obtained, so that the waiting time of each user can be reduced. Can be planned.

In the above-described embodiment, a configuration example in which the output image reading unit 80 is arranged inside the image forming apparatus 1 (after the fixing unit 60) has been described.

As another example, an image forming system in which a dedicated output image reading device is provided outside the image forming apparatus 1 may be used. In this case, the image data acquired by the output image reading device may be stored in a storage unit or the like of the image forming apparatus 1, and the control unit 100 of the image forming apparatus 1 may perform the above-described processing.

In the above-described embodiment, an example of the image forming apparatus 1 provided with the image forming unit 40 of the intermediate transfer method using the electrophotographic process technique has been described. On the other hand, the image forming method in the image forming apparatus 1 is not limited to such a method, and various other methods can be applied.

In addition, the above-described 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 10 Image reading unit 20 Operation display unit (setting unit)
21 Display unit 22 Operation unit 30 Image processing unit 40 Image forming unit 50 Paper transport unit 60 Fixing unit 71 Communication unit (transmitting unit)
72 Storage unit 80 Output image reader (image reader)
100 Control unit (life judgment device, setting unit, life judgment unit, specific unit)
101 CPU
102 ROM
103 RAM
S paper

Claims (16)

It is used to determine whether the image forming member used for image formation has reached the end of its life, and the threshold value of the related parameter related to the occurrence of image defect is based on the actual image judged to be image defect by the user. And the setting part to set
A life determination unit that determines whether or not the image forming member has reached the end of its life based on the actually measured values of the related parameters related to the image formed and the threshold value.
Lifespan determination device. The setting unit sets the threshold value by weighting the actual image that is later determined to be image defect than the actual image that is determined to be image defect earlier by the user.
The life determination device according to claim 1. A transmission unit that transmits the threshold value to an external device is provided.
The life determination device according to claim 1 or 2. The actual image includes an inspection image formed for image inspection.
The life determination device according to any one of claims 1 to 3. When an image defect occurs in the image formed, the image-forming member is provided with a specific portion for identifying the image-forming member that causes the image defect.
The life determination unit determines whether or not the specified image forming member has reached the end of its life based on the measured value and the threshold value.
The life determination device according to any one of claims 1 to 4. The life determination unit determines that the specified image forming member has reached the end of its life when the measured value is equal to or greater than the threshold value, while the specified image forming member determines that the specified image forming member has reached the end of its life. Judge that the forming member has not reached the end of its life,
The life determination device according to claim 5. When the life-determining unit determines that the specified image-forming member has not reached the end of its life, the life-determining unit reaches the end of the life of the image-forming member based on the usage history and / or image-forming conditions of the image-forming member. Predict the time of
The life determination device according to claim 6. The usage history includes the usage amount of the identified image forming member.
The life determination device according to claim 7. The usage history includes changes in the physical property values of the identified image-forming member.
The life determination device according to claim 7. The related parameter is the density difference in the image.
The life determination device according to any one of claims 1 to 9. The image forming condition includes the temperature and humidity around the life determination device.
The life determination device according to any one of claims 7 to 10. The image forming condition includes the number of images formed per unit time.
The life determination device according to any one of claims 7 to 10. The image forming condition includes the number of images formed per unit printing job.
The life determination device according to any one of claims 7 to 10. When the life-determining unit determines that the image-forming member has not reached the end of its life, the life-determining unit reaches the end of the life of the image-forming member based on a plurality of causative parameters caused by a change in the life of the image-forming member. Predict time,
The life determination device according to claim 7. It is used to determine whether the image forming member used for image formation has reached the end of its life, and the threshold value of the related parameter related to the occurrence of image defect is based on the actual image judged to be image defect by the user. Set and set
It is determined whether or not the image forming member has reached the end of its life based on the actually measured values of the related parameters and the threshold value of the image formed.
Life judgment method. On the computer
It is used to determine whether the image forming member used for image formation has reached the end of its life, and the threshold value of the related parameter related to the occurrence of image defect is based on the actual image judged to be image defect by the user. And the process to set
A process of determining whether or not the image forming member has reached the end of its life based on the actually measured values of the related parameters and the threshold value of the image formed.
Life judgment program to execute.

Images