Image forming device, processing system and program

Abstract

To suppress the occurrence of in-machine contamination or BCO when forming an image under various conditions with respect to charging and exposure, compared to a configuration in which a toner image is lastly formed without performing charging or exposing.SOLUTION: There is provided an image forming device which comprises an image forming part which transfers a toner image formed on an image holder to a recording medium by an electrophotographic method and one or a plurality of processors which control operations of the image forming part, wherein the processors includes at least an operation of forming a toner image by charging and exposing an image holder and an operation of forming a toner image without charging and exposing the image holder, when a plurality of operations with different conditions regarding charging and exposure are performed by the image forming part, an operation of forming a toner image by performing charging and exposing is lastly performed.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to an image forming apparatus, a processing system, and a program. [Background technology]

[0002] Electrophotographic image forming apparatuses have a function of forming a toner image without charging or exposing a photosensitive drum, and malfunctions in the apparatus are examined using images formed under various conditions regarding charging and exposure. Prior art document 1 discloses that an exposure system uniformly exposes the entire surface of a photosensitive drum to light, forming a toner image on the drum, which is then transferred to transfer paper and fixed to create a test sample S1, and then similarly pre-exposure and primary charging are performed, exposure by the exposure system is blocked to create a test sample S2, and the cause of exposure unevenness in the exposure sequence is identified based on the results of determining whether or not there is exposure unevenness in sample S1 with uniform exposure over the entire surface and whether or not there is exposure unevenness that has disappeared in sample S2 with exposure blocked. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 7-68842 Summary of the Invention [Problem to be solved by the invention]

[0004] If a toner image is formed without charging or exposing the photosensitive drum, there is a possibility that toner may accumulate in places inside the developing device where it should not be supplied, resulting in contamination inside the device, or that the carrier contained in the developer may migrate onto the photosensitive drum (bead-carry-out).

[0005] The present invention aims to suppress the occurrence of in-machine contamination and BCO when forming images under various conditions regarding charging and exposure, compared to a configuration in which a toner image that is not charged or exposed is formed last. [Means for solving the problem]

[0006] The invention described in claim 1 is an image forming apparatus comprising an image forming unit that transfers a toner image formed on an image holder by an electrophotographic method to a recording medium, and one or more processors that control the operation of the image forming unit, wherein the processor causes the image forming unit to perform a plurality of operations with different conditions related to charging and exposure, including at least an operation of charging and exposing the image holder to form a toner image, and an operation of forming a toner image without charging or exposing the image holder, and then causes the processor to later perform an operation of charging and exposing to form a toner image. The invention described in claim 2 is the image forming apparatus described in claim 1, characterized in that when the operations to be performed by the image forming unit include an operation of charging and exposing an image carrier to form a toner image, and an operation of charging the image carrier and forming a toner image without exposing it to light, the processor later causes the operation of charging and exposing to light to form a toner image to be performed. The invention described in claim 3 is the image forming apparatus described in claim 2, characterized in that when the operations that the processor causes the image forming unit to execute include an operation of forming a toner image without charging or exposing an image carrier, and an operation of charging the image carrier and forming a toner image without exposing it, the operation of charging and forming a toner image without exposing it is executed later. The invention described in claim 4 is the image forming apparatus described in claim 1, characterized in that the image forming unit is capable of operating in a normal mode, which is a normal image output, and a diagnostic mode for diagnosing the image forming unit, as an operation for forming a toner image, and the processor, in operation in the diagnostic mode, causes the image carrier to perform an operation of forming a toner image with charging and exposure conditions different from those in the normal mode, and finally causes the image carrier to perform an operation of forming a toner image with charging and exposure conditions the same as those in the normal mode. The invention described in claim 5 is the image forming apparatus described in claim 4, characterized in that, when operating in the diagnostic mode, the processor executes an operation of forming a toner image without charging or exposing the image carrier to light under conditions different from those in the normal mode to form a toner image, after an operation of forming a toner image without charging or exposing the image carrier, and before an operation under the same conditions as those in the normal mode. The invention described in claim 6 is a processing system comprising an image forming apparatus as described in claims 1 to 5, a reading device that reads the recording medium on which a toner image is formed by the image forming apparatus, a display device that displays an image of the recording medium read by the reading device, a reception device that accepts input of an evaluation result of the image displayed on the display device, and a diagnostic device that diagnoses the condition of the image forming apparatus based on the evaluation result accepted by the reception device. The invention described in claim 7 is the processing system described in claim 6, characterized in that the reading device reads the recording medium in the reverse order to the order in which it was output by the image forming device, and the display device displays images of the recording medium in the order in which it was read by the reading device. The invention described in claim 8 is a program for controlling the computer of an image forming apparatus including an image forming unit having a function of transferring a toner image formed on an image holder by an electrophotographic method to a recording medium and forming a toner image without charging and exposing the image holder, and a computer for controlling the operation of the image forming unit, characterized in that when the image forming unit is to perform multiple operations with different conditions regarding charging and exposing the image holder, the program causes the computer to perform a process of forming a toner image without charging and exposing the image holder, and then to perform a process of charging and exposing the image holder to form a toner image. Effect of the Invention

[0007] According to the first aspect of the present invention, in-machine contamination and the occurrence of BCO can be suppressed, compared to a configuration in which a toner image that is not charged or exposed to light is formed last. According to the invention of claim 2, it is possible to suppress the occurrence of contamination inside the machine and BCO, compared to a configuration in which a toner image that is not charged or exposed to light is formed last. According to the invention of claim 3, it is possible to suppress the occurrence of contamination inside the machine and BCO, compared to a configuration in which a non-charged toner image is formed last. According to the invention of claim 4, compared to a configuration in which a toner image that is not charged or exposed is formed last, an image is formed last under the same conditions as in the normal mode, making it possible to suppress in-machine contamination and the occurrence of BCO. According to the invention of claim 5, compared to a configuration in which a toner image is finally formed under conditions different from those used in normal mode operation, image formation is performed last under the same conditions as in normal mode, making it possible to suppress in-machine contamination and the occurrence of BCO. According to the invention of claim 6, the state of the image forming apparatus can be diagnosed based on images outputted under different conditions related to charging and exposure. According to the invention of claim 7, by first displaying the image formed by charging and exposing, it is possible to identify and evaluate a portion of interest in the image. According to the eighth aspect of the present invention, in-machine contamination and the occurrence of BCO can be suppressed, compared to a configuration in which a toner image that is not charged or exposed to light is formed last. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram showing a configuration of a processing system to which the present embodiment is applied. [Diagram 2] 1 is a diagram illustrating an image forming apparatus according to an embodiment of the present invention. [Diagram 3] FIG. 2 is a diagram illustrating an example of an image forming unit. [Figure 4] FIG. 1 illustrates an example of a hardware configuration of a control device. [Diagram 5]These are diagrams showing the state of the image forming unit in the diagnostic mode, where Figure 5(A) is a diagram showing the state of the image forming unit under a first image forming condition, Figure 5(B) is a diagram showing the state of the image forming unit under a second image forming condition, Figure 5(C) is a diagram showing the state of the image forming unit under a third image forming condition, Figure 5(D) is a diagram showing the state of the image forming unit under a fourth image forming condition, and Figure 5(E) is a diagram showing the state of the image forming unit under a fifth image forming condition. [Figure 6] FIG. 13 is a diagram showing the order in which sheets are output. [Figure 7] FIG. 13 is a diagram showing the order in which the paper is visually recognized. [Figure 8] FIG. 1 illustrates an example of the configuration of an information processing device. [Figure 9] FIG. 13 is a diagram showing an example of an evaluation input screen. [Figure 10] FIG. 13 is a diagram showing an example of a diagnosis result screen. [Figure 11] FIG. 13 is a diagram illustrating an example of diagnosis of an image forming apparatus. [Figure 12] 11A and 11B are diagrams illustrating an example of a diagnosis result of an image forming apparatus. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. <Processing system configuration> 1 is a diagram showing the configuration of a processing system 1 to which the present embodiment is applied. The processing system 1 includes an image forming apparatus 2 and an information processing apparatus 3. The apparatuses 2 and 3 are connected via a network. The network is a communication means used for information communication between the image forming apparatus 2 and the information processing apparatus 3, and for example, a LAN (Local Area Network) is used. The image forming apparatus 2 and the information processing apparatus 3 may be connected via the Internet or a public line, or the image forming apparatus 2 and the information processing apparatus 3 may be directly connected via a communication cable.

[0010] The image forming device 2 is a device that reads an original and forms an image on a sheet P, which is an example of a recording medium, in response to a user's operation. The information processing device 3 is a device that reads the sheet P on which the image has been formed, and determines the state of the image forming device 2. The information processing device 3 will be described later.

[0011] <Configuration of Image Forming Apparatus> FIG. 2 is a diagram showing an image forming apparatus 2 according to the present embodiment. As shown in FIG. 2, the image forming apparatus 2 has a housing 10. In the image forming apparatus 2, an image forming section 20, an intermediate transfer belt 30, a secondary transfer roll 40, a belt cleaner 50, a paper feed section 60, a fixing device 70, a display device 80, and a control device 90 are provided in the housing 10. The image forming apparatus 2 also has a communication interface (not shown) used for information communication. On the top surface of the housing 10, an image reading device 100 that reads an image of a document placed on a document table is disposed. The dashed line shown in FIG. 2 indicates a transport path (R1) for the paper P. In this embodiment, the image forming apparatus 2 employs an electrophotographic system.

[0012] FIG. 3 is a diagram illustrating an example of the image forming unit 20. As shown in FIG. The image forming unit 20 is configured using four image forming units 20Y, 20M, 20C, and 20K that individually form toner images of four colors, for example, yellow (Y), magenta (M), cyan (C), and black (K). In Fig. 3, the image forming unit 20 will be described using one of the image forming units 20 (Y, M, C, K).

[0013] The image forming unit 20 is provided with a photoconductor drum 21. The photoconductor drum 21 receives power from a drive device (not shown) and rotates in the direction of arrow A to form an electrostatic latent image. In addition, a charging device 22, an exposure device 23, a developing device 24, a primary transfer roll 25, and a drum cleaner 26 are provided around the photoconductor drum 21. The charging device 22 charges the surface of the photoconductor drum 21 to a predetermined potential.

[0014] The exposure device 23 exposes the photoconductor drum 21 to, for example, a laser beam, thereby forming an electrostatic latent image on the surface. In FIG. 3, the light emitted from the exposure device 23 is indicated by the symbol Bm. The potential of the exposed portion of the photoconductor drum 21, which has been charged by the charging device 22, decreases. Note that the exposure of the photoconductor drum 21 by the exposure device 23 is not limited to using a laser beam. For example, a light source such as an LED (Light Emitting Diode) may be provided for each image forming unit 20, and the photoconductor drum 21 may be exposed to light emitted from the light source.

[0015] The developing device 24 visualizes the electrostatic latent image formed on the photosensitive drum 21 with a developer. The developing device 24 includes a storage section 241 that stores the developer. The storage section 241 is formed of, for example, a resin storage housing. The developing device 24 is disposed so as to extend in a direction from the front side to the rear side of the image forming apparatus 2 (a direction perpendicular to the paper surface of FIG. 3).

[0016] Further, the storage section 241 is provided with an opening 243 at a position facing the photosensitive drum 21 (see FIG. 3). The opening 243 is provided with a developing roll 245 for adhering toner to the surface of the photosensitive drum 21. The developing roll 245 is formed in a cylindrical shape and arranged to extend along a direction from the front side to the rear side of the image forming apparatus 2 (a direction perpendicular to the paper surface of FIG. 3). The developing roll 245 receives power from a driving device (not shown) and adheres toner to the surface of the photosensitive drum 21 while rotating in the direction of arrow C shown in FIG. 3.

[0017] The developer in this embodiment is composed of a powdered dry carrier and a powdered dry toner, and each of the image forming units 20 (Y, M, C, K) uses the powdered dry carrier and the powdered dry toner to form a toner image on the photoconductor drum 21. In this example, the carrier has a positive charging polarity, and the toner has a negative charging polarity.

[0018] The primary transfer roll 25 electrostatically transfers the toner image formed on the photoconductor drum 21 onto the image bearing surface of the intermediate transfer belt 30 at the primary transfer position T1. At the primary transfer position T1, a potential difference (primary transfer bias) is generated between the photoconductor drum 21 and the primary transfer roll 25, so that the toner image on the photoconductor drum 21 is transferred to the intermediate transfer belt 30 sandwiched between the photoconductor drum 21 and the primary transfer roll 25. The drum cleaner 26 is a cleaning member that removes residual toner on the surface of the photoconductor drum 21 after the primary transfer.

[0019] The intermediate transfer belt 30 conveys the toner image transferred onto its image bearing surface to a secondary transfer position T2. ​​As shown in FIG. 2, the intermediate transfer belt 30 is disposed below the image forming units 20 (Y, M, C, K). The intermediate transfer belt 30 is disposed in a state sandwiched between the photoconductor drums 21 and primary transfer rolls 25 provided in each of the image forming units 20 (Y, M, C, K). As shown in FIG. 2, the intermediate transfer belt 30 is rotated at a predetermined speed in the direction of arrow B by a drive roll 31a and support rolls 31b-e driven by a drive device (not shown).

[0020] The support roll 31b cooperates with the drive roll 31a to hold the primary transfer surface. The support roll 31c applies tension to the intermediate transfer belt 30. The support roll 31d is a backup roll that supports the transfer performed by the secondary transfer roll 40. The support roll 31e is a roll that supports the belt cleaner 50 in cleaning the residual toner on the intermediate transfer belt after the secondary transfer.

[0021] The secondary transfer roll 40 electrostatically transfers the toner image held on the image holding surface of the intermediate transfer belt 30 to the paper P at the secondary transfer position T2. ​​As shown in FIG. 2, the secondary transfer roll 40 is disposed facing the support roll 31d via the intermediate transfer belt 30. At the secondary transfer position T2, a potential difference (secondary transfer bias) is generated between the support roll 31d and the secondary transfer roll 40, so that the toner image is transferred from the intermediate transfer belt 30 sandwiched between the support roll 31d and the secondary transfer roll 40 to the paper P. The belt cleaner 50 is a cleaning member that removes residual toner and the like on the intermediate transfer belt 30 after the secondary transfer.

[0022] The paper feed section 60 is composed of a paper container 61 and a plurality of feed rolls 62. The paper container 61 stores various types of paper P to be supplied to the secondary transfer position T2. ​​The feed rolls 62 send out the paper P one by one from the paper container 61 to the paper transport path R1, and transport the paper P to the secondary transfer position T2. ​​As shown in FIG. 2, the paper feed section 60 is disposed below the intermediate transfer belt 30. The number of paper containers 61 may be increased or decreased as necessary. In addition, a manual feed tray (not shown) connected to the paper transport path R1 may be disposed outside the housing 10.

[0023] The fixing device 70 is a device that fixes the toner image that has been secondarily transferred onto the paper P. As shown in Fig. 2, the fixing device 70 is disposed below the intermediate transfer belt 30. The fixing device 70 also includes a heating roll and a pressure roll, and as shown in Fig. 2, a fixing process is performed on the paper P by applying heat and pressure at a position where the heating roll and the pressure roll come into contact with each other.

[0024] The paper transport path R1 is a path along which the paper P is transported, and is provided to connect from the paper feed unit 60 to a paper discharge tray (not shown). The paper transport path R1 is indicated by a dashed line in FIG. 2. As shown in FIG. 2, the feed roll 62, the transport roll 71, and the discharge roll 72 are arranged on the paper transport path R1. As described above, the feed roll 62 sends out the paper P from the paper container 61 to the paper transport path R1 and transports it to the secondary transfer position T2. ​​The transport roll 71 transports the paper P onto which the toner image has been transferred at the secondary transfer position to the fixing device 70. The discharge roll 72 transports the paper P onto which the toner image has been fixed to the paper discharge tray (not shown).

[0025] The display device 80 is, for example, a display installed on the outer surface of a housing. The display device 80 receives instructions from a user and displays information to the user. The display device 80 is, for example, configured with a touch panel or the like, and is used as a display device and an operation device.

[0026] The control device 90 is provided inside the housing 10 and controls each operation of the image forming device 2. For example, operations such as image reading and image formation, and an image formation operation in a diagnostic mode described later, are controlled by the control device 90. These operations are performed by a CPU 91a (see FIG. 4) as an example of a processor described later, which loads a program stored in an information storage device 92 or the like into a RAM 91c used as a work area and executes it.

[0027] <Control device hardware configuration> FIG. 4 is a diagram showing an example of the hardware configuration of the control device 90. As shown in FIG. The control device 90 is provided with an arithmetic processing unit 91 and an information storage device 92 that stores information. The arithmetic processing unit 91 is configured by a computer. The arithmetic processing unit 91 has a CPU (Central Processing Unit) 91a as an example of a processor that executes various processes described later. The arithmetic processing unit 91 also has a ROM (Read Only Memory) 91b in which a program is stored and a RAM (Random Access Memory) 91c used as a work area. The information storage device 92 is realized by an existing device such as a hard disk drive or a semiconductor memory. The arithmetic processing unit 91 and the information storage device 92 are connected via a bus 93 or a signal line (not shown).

[0028] The program executed by the CPU 91a may be provided to the control device 90 in a state where it is stored in a computer-readable recording medium such as a magnetic recording medium (magnetic tape, magnetic disk, etc.), an optical recording medium (optical disk, etc.), a magneto-optical recording medium, or a semiconductor memory. The program executed by the CPU 91a may also be provided to the control device 90 using a communication means such as the Internet. The program provided to the control device 90 is stored in the information storage device 92.

[0029] In this specification, the term "processor" refers to a processor in a broad sense, including general-purpose processors (e.g., CPU: Central Processing Unit, etc.) and dedicated processors (e.g., GPU: Graphics Processing Unit, ASIC: Application Specific Integrated Circuit, FPGA: Field Programmable Gate Array, programmable logic device, etc.). In addition, the operations of the processor may not only be performed by one processor, but may be performed by multiple processors in physically separate locations working together. The order of the operations of the processor is not limited to the order described in this embodiment, and may be changed.

[0030] <Image Forming Operation by Image Forming Apparatus> Next, the image forming operation performed by the image forming apparatus 2 will be described with reference to Figures 2 and 3. This operation is performed by a CPU 91a, which is an example of a processor, reading a program stored in a ROM 91b or the like into a RAM 91c used as a work area and executing it. Here, a case where a full-color image is formed by combining toner images of four colors (Y, M, C, K) will be described as an example. On the other hand, it is also possible to form a monochrome image by operating only the image forming unit 20(K), for example.

[0031] For example, when the image forming device 2 receives a request for an image forming operation by a user's operation, the image forming device 2 rotates the photoconductor drum 21 in each image forming unit 20 (Y, M, C, K) in the direction of arrow A. Next, the charging device 22 charges the surface of each photoconductor drum 21 to a predetermined potential.

[0032] Furthermore, when image data output from the image reading device 100, a PC, or the like is received together with a request for an image forming operation, the image forming device 2 performs image processing on the image data. As a result, image data corresponding to each image forming unit 20 (Y, M, C, K) is generated. The generated image data is then output to the exposure device 23.

[0033] The exposure device 23 irradiates the photoconductor drum 21 with light emitted from, for example, a laser in accordance with the input image data. In this embodiment, after the surface of each photoconductor drum 21 is charged to a predetermined potential by the charging device 22, the surface is exposed by the exposure device 23. As a result, an electrostatic latent image of the predetermined potential is formed on the surface of the photoconductor drum 21.

[0034] Next, the developing device 24 causes the developing roll 245 to adhere toner to the electrostatic latent image formed on the surface of the photoconductor drum 21. As a result, a toner image corresponding to each of the four colors (Y, M, C, K) is formed individually on the surface of each photoconductor drum 21.

[0035] Next, as the intermediate transfer belt 30 rotates in the direction of arrow B, the toner images formed on the surfaces of the photoconductor drums 21 of the image forming units 20 (Y, M, C, K) are electrostatically transferred in order (Y, M, C, K) to the image bearing surface of the intermediate transfer belt 30 at the primary transfer position T1. In addition, the toner remaining on the image bearing surface of the photoconductor drum 21 is cleaned by the drum cleaner 26.

[0036] Next, as the intermediate transfer belt 30 further rotates in the direction of arrow B, the intermediate transfer belt 30 transports the toner image that has been primarily transferred and held on its image bearing surface to secondary transfer position T2. ​​Meanwhile, in the paper feed section 60, a feed roll 62 sends out paper P from a paper container 61 through paper conveyance path R1 to secondary transfer position T2. ​​Then, at secondary transfer position T2, the toner image held on the image bearing surface of the intermediate transfer belt 30 is secondarily transferred to the paper P. In addition, the toner remaining on the image bearing surface of the intermediate transfer belt 30 is cleaned by a belt cleaner 50.

[0037] Next, the paper P onto which the toner image has been transferred is transported to the fixing device 70 by the transport rolls 71. Then, in the fixing device 70, the paper P is heated and pressed by a heating roll and a pressure roll. This causes the toner image on the paper P to be fixed to the paper P. Then, the paper P is discharged to a discharge tray (not shown) by the discharge rolls 72. The above operations are the image forming operation performed when performing a normal image forming operation (normal time) in the image forming apparatus 2 of this embodiment. When a request for image forming operation for multiple sheets is received, the image forming operation described above is similarly repeated for the number of sheets.

[0038] Here, in this embodiment, it is possible to diagnose a malfunction for each of the image forming units 20 (Y, M, C, K). More specifically, in this embodiment, it is possible to identify the presence or absence of a malfunction and to identify the location of the malfunction for each of the image forming units 20 (Y, M, C, K). In this embodiment, when diagnosing an image forming unit 20, for example, first, an operator or other such person operates the display device 80 or the like to specify the image forming unit 20 to be diagnosed.

[0039] In this embodiment, the image forming unit 20 designated by the operator as Y, M, C, or K is the target of diagnosis. The image forming unit 20 to be diagnosed may be designated by the control device 90 of the image forming device 2 according to a predetermined condition, not by the operator. The control device 90 may designate each image forming unit 20 (Y, M, C, K) in order, so that diagnosis is performed for all image forming units 20. When diagnosing the image forming unit 20, the image forming device 2 performs image forming operations in order under a plurality of image forming conditions described later, and forms diagnostic images (hereinafter, diagnostic images are referred to as "diagnostic images") obtained under each image forming condition on the paper P. In the following, in describing the diagnostic image forming operation, the case where a normal image forming operation is performed as described above is referred to as a normal mode. Also, the case where a diagnostic image forming operation is performed is referred to as a diagnostic mode. Each mode is performed by the CPU 91a, which is an example of a processor, reading a program stored in the information storage device 92 or the like into the RAM 91c used as a work area and executing it.

[0040] <Diagnostic mode> In the diagnosis mode in this embodiment, there are five image forming conditions, from the first image forming condition to the fifth image forming condition. In this embodiment, image forming operations under these image forming conditions are performed on the image forming unit 20 to be diagnosed in a predetermined order, and the obtained diagnostic image is formed on the paper P. Note that, in this embodiment, diagnosis is performed using the five image forming conditions, but some of these image forming conditions may be specified and used.

[0041] Figure 5 is a diagram showing the state of the image forming unit 20 in the diagnostic mode, where Figure 5(A) is a diagram showing the state of the image forming unit 20 under a first image forming condition, Figure 5(B) is a diagram showing the state of the image forming unit 20 under a second image forming condition, Figure 5(C) is a diagram showing the state of the image forming unit 20 under a third image forming condition, Figure 5(D) is a diagram showing the state of the image forming unit 20 under a fourth image forming condition, and Figure 5(E) is a diagram showing the state of the image forming unit 20 under a fifth image forming condition. In explaining the potentials in FIG. 5, the potential of the photoconductor drum 21 is represented by a solid line, and the potential of the developing roll 245 is represented by a dashed line.

[0042] <First image forming conditions> In the first image forming condition shown in Fig. 5(A), the image forming unit 20 is in the same state as in the normal mode. In other words, the first image forming condition is the same as the image forming condition in the normal mode. In this embodiment, in the normal mode, as shown in Fig. 5(A), the photoconductor drum 21 is charged using the charging device 22, and the surface potential of the photoconductor drum 21 is set to VH.

[0043] Furthermore, during normal operation, the exposure device 23 is used to selectively irradiate the surface of the photoconductor drum 21 with light. Then, as shown in FIG. 5A, the potential of the photoconductor drum 21 is set to a potential VL that is lower than the potential of the development roll 245 for the portion on which the image is to be formed. As a result, toner from the development roll 245 adheres to the portion of the photoconductor drum 21 that has been set to potential VL, and a toner image is formed on the portion that has been set to potential VL. Then, this toner image is transferred to the paper P via the intermediate transfer belt 30, and the toner image is formed on the paper P. As a result, a diagnostic image is formed on the paper P.

[0044] In normal cases, when the density of the image to be formed is reduced, a period during which the photoconductor drum 21 is not irradiated with light is provided in addition to a period during which the photoconductor drum 21 is irradiated with light, so that a non-image forming portion is formed where no image is formed, as shown by reference symbol 5a in Fig. 5(A). A dot-shaped toner image is formed in the portion of the photoconductor drum 21 that is irradiated with light, but no toner adheres to the portion not irradiated with light, resulting in a blank region.

[0045] In this embodiment, the density of the image formed changes depending on the size of the dot-shaped toner image and the size of the blank area, and when the blank area becomes relatively large, the image density appears to the user to be reduced.

[0046] <Second image forming conditions> 5B, similarly to the above, the photoconductor drum 21 is charged, and the surface potential of the photoconductor drum 21 is set to VH. Moreover, under the second image forming condition, the exposure device 23 is used to continuously irradiate the photoconductor drum 21 with light. In other words, under the second image forming condition, the photoconductor drum 21 is continuously irradiated with light so that the blank area is not formed.

[0047] Moreover, under the second image forming condition, a diagnostic image with a low image density is formed. Specifically, under the second image forming condition, the output of the exposure device 23 is reduced compared to the normal time shown in FIG. 5A, and the difference Vs between the potential of the surface of the photoconductor drum 21 and the potential of the developing roll 245 is reduced. As a result, under the second image forming condition, a diagnostic image with a low image density is formed. Here, under the second image forming condition, when forming a diagnostic image with a low image density, a blank area is not provided as described above, but the exposure amount itself is reduced to form a diagnostic image with a low density.

[0048] Under the second image forming condition, exposure is performed uniformly with a low exposure output, and toner from the developing roll 245 adheres to the entire area where this exposure is performed uniformly, and a diagnostic image is formed over the entire area. Under the second image forming condition, if there is unevenness in the light emitted from the exposure device 23, the shading caused by this unevenness appears more clearly in the diagnostic image that is formed. In this case, it is possible to identify a problem with the image forming unit 20 to be diagnosed.

[0049] When the density of the image is reduced by creating dot images and blank areas as in the above normal state, even if there is unevenness in the formed dot images, the effect of this unevenness is unlikely to appear in the diagnostic image. In contrast, under the second image forming condition shown in Fig. 5(B), for example, density unevenness appears more prominently in the diagnostic image, making it clearer that there is a problem with the image forming unit 20.

[0050] <Third image forming condition> 5(C), the charging potential VH of the photoconductor drum 21 and the potential of the developing roll 245 are made smaller than those in the second image forming condition. Also, in the third image forming condition, the exposure device 23 is used to continuously irradiate the photoconductor drum 21 with light, and the output of the exposure device 23 is increased compared to those in the second image forming condition.

[0051] Under the third image forming condition, the charged potential VH of the photoconductor drum 21 is small, and furthermore, the output of the exposure device 23 is increased, so that when exposure is performed, the potential of the photoconductor drum 21 drops to the residual potential of the photoconductor drum 21. Furthermore, under the third image forming condition, the surface of the photoconductor drum 21 is uniformly exposed, as in the above. Over the entire area where this exposure has been performed uniformly, toner from the developing roll 245 adheres, and a diagnostic image is formed over the entire area.

[0052] Under the third image forming condition, even if there is a malfunction in the charging device 22 or the exposure device 23, the influence of the malfunction will not affect the potential of the photoconductor drum 21. In this case, even if there is a malfunction in the charging device 22 or the exposure device 23, the influence of the malfunction will not be easily seen in the diagnostic image. Under this condition, regardless of the presence or absence of a malfunction in the charging device 22 or the exposure device 23, the potential of the photoconductor drum 21 will drop to the residual potential, and regardless of the presence or absence of a malfunction in the charging device 22 or the exposure device 23, the potential of the photoconductor drum 21 will be a constant potential value.

[0053] Here, it is assumed that an image defect such as uneven density or streaks appears in the diagnostic image formed under the second image forming condition described above, where the potential of the photoconductor drum 21 does not drop to the residual potential. On the other hand, it is assumed that the image defect does not appear in the diagnostic image formed under the third image forming condition, where the potential of the photoconductor drum 21 drops to the residual potential. In this case, it becomes possible to detect that there is no problem with the developing device 24 or the primary transfer roll 25.

[0054] <Fourth image forming condition> In the fourth image forming condition shown in FIG. 5(D), as indicated by reference numeral 5d in FIG. 5(D), the potential of the developing roll 245 is made higher than the charging potential VH of the photoconductor drum 21. In addition, in this fourth image forming condition, the exposure process is not performed on the photoconductor drum 21. Since the exposure process is not performed, the potential of the photoconductor drum 21 does not decrease, but since the potential of the developing roll 245 is increased, a development bias is generated between the photoconductor drum 21 and the developing roll 245. Therefore, in this case as well, the toner from the developing roll 245 adheres to the surface of the photoconductor drum 21, and a uniform toner image is formed on the surface of the photoconductor drum 21.

[0055] In the case of the fourth image forming condition, since the exposure process is not performed, the toner adhesion location is not controlled. Therefore, the toner from the developing roll 245 adheres to the entire surface of the charged photoconductor drum 21, and a diagnostic image is formed over the entire surface.

[0056] Under the fourth image forming condition, it is possible to detect whether or not there is a malfunction in the exposure device 23. Here, if, for example, a streak-like image defect occurs in the diagnostic image under the above-mentioned second image forming condition in which the charging process and the exposure process are performed, and if this streak-like image defect does not occur under the fourth image forming condition in which the exposure process is not performed, it is possible to detect that there is a malfunction in the exposure device 23.

[0057] <Fifth Image Forming Condition> In the fifth image forming condition shown in FIG. 5(E), the potential of the photoconductor drum 21 is set to zero. That is, in the fifth image forming condition, the photoconductor drum 21 is not charged. In addition, the potential of the developing roll 245 is set higher than the potential of the photoconductor drum 21. In the fifth image forming condition, the photoconductor drum 21 is not exposed. In the fifth image forming condition, neither the charging nor the exposure is performed, but the potential of the developing roll 245 is increased, so that a developing bias is generated between the photoconductor drum 21 and the developing roll 245. As a result, the toner from the developing roll 245 adheres to the surface of the photoconductor drum 21. In this case, a diagnostic image is also formed over the entire surface of the photoconductor drum 21.

[0058] Under the fifth image forming condition, it is possible to detect a malfunction that may exist in the charging device 22 or the exposure device 23. Here, if an image defect occurs under the above-mentioned second image forming condition in which the charging process and the exposure process are performed, and this image defect does not occur under the fifth image forming condition in which the charging process and the exposure process are not performed, it is possible to detect that there is a malfunction in either the charging device 22 or the exposure device 23.

[0059] Here, the above-mentioned second image forming condition can be said to be a condition for identifying whether or not a malfunction has occurred in the image forming unit 20 of the diagnosis target. Also, the diagnostic image formed under the second image forming condition can be said to be a diagnostic image for identifying whether or not a malfunction has occurred in the image forming unit 20 of the diagnosis target.

[0060] The third to fifth image forming conditions can be considered as conditions for identifying a component having a malfunction among the multiple components constituting the image forming unit 20 to be diagnosed. The diagnostic images formed under the third to fifth image forming conditions can be considered as diagnostic images for identifying a component having a malfunction among the multiple components constituting the image forming unit 20 to be diagnosed.

[0061] <Secondary damage caused by diagnostic mode> In this embodiment, when the diagnosis mode is executed by the operator, an image forming operation is performed on the image forming unit 20 to be diagnosed using five image forming conditions. Therefore, under conditions different from the normal image forming conditions, for example, special image forming conditions in which charging processing, exposure processing, etc. are not performed, secondary failures may occur. Specifically, secondary failures include in-machine contamination in which toner accumulates in places where toner should not be supplied, and bead-carry-out (BCO), in which carrier in the developing device 24 moves to the photoconductor drum 21. Note that when a secondary failure occurs, a dot image originating from the toner or carrier is formed on the output paper P.

[0062] For example, in the fifth image forming condition, charging and exposure processes are not performed. Therefore, as shown in FIG. 5E, the potential of the developing roll 245 is made higher than the potential of the photoconductor drum 21 to generate a developing bias between the photoconductor drum 21 and the developing roll 245, thereby forming a toner image. Therefore, depending on the potential difference between the photoconductor drum 21 and the developing roll 245, there is a risk of contamination inside the machine or BCO occurring.

[0063] In the fourth image forming condition, the charging process is performed but the exposure process is not performed. Therefore, as shown in Fig. 5(D), the potential of the developing roll 245 is made higher than the charging potential VH of the photoconductor drum 21, thereby generating a developing bias between the photoconductor drum 21 and the developing roll 245 to form a toner image. In this case, too, there is a risk of in-machine contamination or BCO occurring depending on the potential difference between the photoconductor drum 21 and the developing roll 245.

[0064] In addition, in each of the first to third image forming conditions, the charging process and the exposure process are performed as described above. Therefore, in each of the first to third image forming conditions, the potential of the developing roll 245 does not become higher than the charging potential VH of the photoconductor drum 21. The toner and carrier in the developing device 24 are attracted to the developing roll 245. Therefore, the possibility of a secondary failure occurring is low compared to when the image forming operation is performed using the fifth or fourth image forming condition.

[0065] <Execution sequence of image formation operations in diagnostic mode> In the diagnosis mode in this embodiment, image forming operations are performed in order starting from the fifth image forming condition, and finally, image forming operations are performed under the first image forming condition. Therefore, between an operation of forming a toner image by performing charging and exposure processes on the photoconductor drum 21 and an operation of forming a toner image without performing charging and exposure processes on the photoconductor drum 21, the operation of forming a toner image by performing charging and exposure processes is executed later. Also, between an operation of forming a toner image by performing charging and exposure processes on the photoconductor drum 21 and an operation of forming a toner image by performing charging and exposure processes on the photoconductor drum 21 and without performing exposure processes on the photoconductor drum 21, the operation of forming a toner image by performing charging and exposure processes is executed later. Also, between an operation of forming a toner image without performing charging and exposure processes on the photoconductor drum 21 and an operation of forming a toner image by performing charging and exposure processes on the photoconductor drum 21 and without performing exposure processes on the photoconductor drum 21, the operation of forming a toner image by performing charging and without performing exposure processes is executed later.

[0066] Also, in the operation in the diagnosis mode, an operation is performed to form a toner image on the photoconductor drum 21 under conditions different from those in the normal mode for the charging process and the exposure process, and then finally an operation is performed to form a toner image on the photoconductor drum 21 under conditions the same as those in the normal mode for the charging process and the exposure process. Also, in the operation in the diagnosis mode, the operation to form a toner image by performing the charging process and the exposure process on the photoconductor drum 21 under conditions different from those in the normal mode is performed after the operation to form a toner image without performing the charging process or the exposure process on the photoconductor drum 21 and before the operation under the same conditions as those in the normal mode.

[0067] FIG. 6 is a diagram showing the output order of the sheets P. As shown in FIG. As shown in Fig. 6, by performing image forming operations in order starting from the fifth image forming condition, in terms of output order, first, a diagnostic image formed in an image forming operation under the fifth image forming condition is output onto paper P. Then, after that, image forming operations under each image forming condition are performed in order, and each diagnostic image is output onto paper P. Then, finally, a diagnostic image formed in an image forming operation under the first image forming condition is output onto paper P. In this way, by performing an image forming operation under the first image forming condition, which is similar to the normal image forming condition, last in a series of image forming operations in the diagnostic mode, toner that causes in-machine contamination can be adhered to paper P even if in-machine contamination occurs under the previous special image forming condition.

[0068] <Detection of image defects> Next, image defects that appear in diagnostic images in the diagnostic mode will be described. An example of an image defect is a streak that appears in a diagnostic image. A streak appears, for example, as a single line along the paper feed direction of the paper P. Streaks include colorless white streaks and colored streaks. When a streak appears in a diagnostic image, a malfunction has occurred in the image forming device 2. In this embodiment, the malfunction of the image forming device 2 is identified based on such an image defect.

[0069] FIG. 7 is a diagram showing the order in which the paper P is visually recognized. As shown in Fig. 7, by performing image forming operations in order starting from the fifth image forming condition, in terms of output order, first, the diagnostic image formed in the image forming operation under the fifth image forming condition is output onto paper P. Then, after that, image forming operations under each image forming condition are performed in order, and each diagnostic image is output onto paper P. Then, lastly, the diagnostic image formed in the image forming operation under the first image forming condition is output onto paper P. Therefore, by checking the topmost paper P of the outputted paper P stack, the operator can visually confirm the last outputted paper P, that is, the diagnostic image outputted under the normal image forming condition.

[0070] Here, if a streak appears in the diagnostic image output under normal image forming conditions, it is determined that the cause of the streak is due to a malfunction of the image forming unit 20. Then, the diagnostic image output under normal image forming conditions can be used as a reference to check diagnostic images under other image forming conditions. Note that the state of the diagnostic image refers to, for example, the presence or absence of streaks in the diagnostic image and the location of the streaks. Then, by comparing the states of the diagnostic images output under each image forming condition, the location of the failure can be identified. The information processing device 3 may be used to identify the location of the failure.

[0071] <Configuration of information processing device 3> FIG. 8 is a diagram showing an example of the configuration of the information processing device 3. The information processing device 3 is provided with an arithmetic processing unit 301, an information storage device 302 that stores information, a display device 303, and an input device 304. The information processing device 3 is also provided with a communication interface (not shown). The arithmetic processing unit 301 is configured by a computer. The arithmetic processing unit 301 has a CPU 301a as an example of a processor that executes various processes described below. The arithmetic processing unit 301 also has a ROM 301b in which a program is stored, and a RAM 301c used as a work area. The information storage device 302 is realized by an existing device such as a hard disk drive or a semiconductor memory. The arithmetic processing unit 301, the information storage device 302, the display device 303, and the input device 304 are connected via a bus 305 or a signal line not shown.

[0072] In addition, the operations of the processor may not only be performed by one processor, but may be performed by multiple processors in physically separate locations working together. The order of the operations of the processor is not limited to the order described in this embodiment, and may be changed.

[0073] The display device 303 is a device that displays information to a user. For example, a display is used as the display device 303. The input device 304 is a device that accepts input from a user. For example, a keyboard, a mouse, a touch sensor, etc. are used as the input device 304. Also, it may be configured as a touch panel that combines a touch sensor and a display. The communication interface is used for information communication with the image forming device 2.

[0074] In this embodiment, the information processing device 3 diagnoses the state of the image forming device 2 based on the diagnostic image formed on the paper P. This operation is performed by the CPU 301a, which is an example of a processor, reading a program stored in the information storage device 302 or the like into the RAM 301c used as a work area and executing the program.

[0075] Specifically, for example, an operator reads the paper P using the image reading device 100 provided in the image forming apparatus 2 in the reverse order to the order in which the paper P was output. Next, the image forming apparatus 2 transmits information on the read paper P to the information processing apparatus 3 using a communication interface between the image forming apparatus 2 and the information processing apparatus 3. Then, the display device 303 displays the diagnostic images in the order in which the paper P was read by the image reading device 100. Then, the operator uses the input device 304 to input an evaluation of the diagnostic images displayed on the display device 303. Then, the CPU 301a of the information processing apparatus 3 diagnoses the state of the image forming apparatus 2 based on the evaluation input by the operator, and displays the result on the display device 303.

[0076] FIG. 9 is a diagram showing an example of the evaluation input screen. In the diagram shown in FIG. 9, a display field 303A for displaying which image forming condition is selected, a display field 303B for displaying a diagnostic image, and a display field 303C for displaying options for the operator to input an evaluation of the diagnostic image are provided. In the display field 303A shown in the figure, one image forming condition is displayed, in the display field 303B, one diagnostic image is displayed, and in the display field 303C, options for receiving an input of an evaluation from the operator are displayed. Then, the operator inputs an evaluation of the diagnostic image while visually checking the diagnostic image for each image forming condition. Note that the arrow shown in the diagnostic image indicates the paper feed direction.

[0077] FIG. 10 is a diagram showing an example of a diagnosis result screen. In the diagram shown in FIG. 10, a screen showing the diagnosis result is displayed. More specifically, the diagnosis result screen is provided with a display field 303D for displaying each of the components of the image forming unit 20, a display field 303E for displaying the failure probability, and a display field 303F for displaying the diagnosis result. In the display field 303D, "LPH", "Drum", "Developer", and "1stBTR" are displayed. Here, "LPH" refers to the exposure device 23. Also, "Drum" refers to the photoconductor drum 21 and the charging device 22. Also, "Developer" refers to the developing device 24. Also, "1stBTR" refers to the primary transfer roll 25. In the display field 303E, the failure probability is displayed. Here, for example, "High", "Medium", and "Low" are displayed in order of the likelihood of failure, and the failure probability is displayed by the number of stars for each. In the display field 303F, the diagnosis result by the CPU 301a is displayed. In the diagram shown in FIG. 10, for example, one star is displayed for "LPH". Therefore, it is understood that there is a low possibility that there is a malfunction in the exposure device 23. The operator visually checks the diagnosis result and identifies the location of the malfunction.

[0078] FIG. 11 is a diagram showing an example of diagnosing the image forming apparatus 2. In FIG. Here, as an example for explaining diagnosis of the image forming device 2 using the information processing device 3, a case will be explained in which color streaks appear in the diagnostic image in each image forming operation under the first image forming condition to the fourth image forming condition, and the streaks disappear in the diagnostic image in the image forming operation under the fifth image forming condition. Note that this is just one example.

[0079] The operator reads the paper P in the reverse order of the paper P output using the image reading device 100 provided in the image forming device 2. That is, the paper P is read in the order starting from the paper P output under the first image forming condition. The first image forming condition is the normal image forming condition as described above. Next, the image forming device 2 transmits the information of the paper P that has been read to the information processing device 3 using the communication interface between the image forming device 2 and the information processing device 3. Then, the CPU 301a of the information processing device 3 displays the diagnostic images on the display device 303 in the order in which they were read by the image reading device 100. That is, the diagnostic images formed under each image forming condition are displayed in order starting from the first image forming condition. As shown in FIG. 11, the display device 303 first displays the diagnostic image under the first image forming condition and options for inputting the state of the diagnostic image. Then, as shown in the figure, color streaks appear in this diagnostic image. Therefore, the operator uses the input device 304 to select the color streaks. In this embodiment, as described above, color streaks occur in the diagnostic images from the first image forming condition to the fourth image forming condition. Therefore, color streaks are selected in each image forming condition from the first image forming condition to the fourth image forming condition. Then, color streaks disappear in the diagnostic image in the fifth image forming condition. Therefore, the operator selects "no streaks" using the input device 304. The CPU 301a diagnoses the fault location based on the input of this evaluation.

[0080] FIG. 12 is a diagram showing the diagnosis result of the image forming apparatus 2. As shown in FIG. In the above example, color streaks appear under the fourth image forming condition where charging is performed but exposure is not performed, and disappear under the fifth image forming condition where charging and exposure are not performed, so the CPU 301a of the information processing device 3 determines that the cause of the color streaks is highly likely to be the charging device 22. Therefore, as shown in FIG. 12, three stars are displayed in "Drum" on the screen showing the diagnosis result. This allows the operator to identify the location of the failure if the charging device 22 in the image forming device 2 is faulty.

[0081] In the above description, the image is read using the image reading device 100 provided in the image forming apparatus 2, but this is not limiting. An image reading device may be provided separately from the image forming apparatus 2. In this case, the information processing apparatus 3 obtains information on the read image from the image reading device using a communication interface.

[0082] The diagnosis of the image forming unit 20 to be diagnosed may be performed by the operator through visual inspection. In this embodiment, the order of performing the image forming operations under each image forming condition is determined in advance, so that by visually checking the output diagnostic images in order, it is possible to identify which diagnostic image was diagnosed under which image forming condition. In this way, the operator may diagnose the image forming unit 20 to be diagnosed.

[0083] Although the embodiment of the present invention has been described above, the technical scope of the present invention is not limited to the above embodiment. For example, in this embodiment, the diagnostic image is outputted on the paper P using five image forming conditions, but the present invention is not limited to this. When diagnosing the image forming unit 20, the image forming conditions to be used may be changed as long as the first image forming condition, the fourth image forming condition, and the fifth image forming condition are included. Even if the image forming conditions to be used are changed, the image forming operation is finally performed using the first image forming condition, that is, the normal image forming condition. This allows the in-machine contamination to be attached to the paper P even if it occurs, and the presence or absence of the in-machine contamination can be determined by checking the outputted paper P.

[0084] In this embodiment, the diagnostic image formed under the first image forming condition is first displayed on the display device 303, and then the diagnostic images are displayed in order up to the fifth image forming condition. However, these diagnostic images may be displayed all at once. Since the display field 303A of the display device 303 indicates which image forming condition an image was formed under, the operator can visually confirm this to identify which diagnostic image was formed under which image forming condition. In addition, various modifications and alternative configurations that do not depart from the scope of the technical idea of ​​the present invention are included in the present invention.

[0085] <Additional Notes> (((1))) An image forming apparatus comprising: an image forming unit that transfers a toner image formed on an image carrier by an electrophotographic method onto a recording medium; and one or more processors that control the operation of the image forming unit, wherein the processor, when causing the image forming unit to perform a plurality of operations with different conditions related to charging and exposure, including at least an operation of forming a toner image by charging and exposing the image carrier and an operation of forming a toner image without charging or exposing the image carrier, later causes the processor to perform an operation of forming a toner image by charging and exposing the image carrier. (((2))) The image forming apparatus described in (((1))), wherein, when the operations to be executed by the image forming unit include an operation of charging and exposing an image carrier to form a toner image, and an operation of charging the image carrier and forming a toner image without exposing it to light, the processor later executes the operation of charging and exposing to light to form a toner image. (((3))) The image forming apparatus described in (((1))) or (((2))), characterized in that when the operations that the processor causes the image forming unit to execute include an operation of forming a toner image without charging or exposing an image carrier, and an operation of charging an image carrier and forming a toner image without exposing it, the operation of charging and forming a toner image without exposing it is executed later. (((4))) The image forming apparatus of any of (((1))) to (((3))), characterized in that the image forming unit is capable of operating in a normal mode for normal image output and a diagnostic mode for diagnosing the image forming unit as an operation for forming a toner image, and the processor, in the operation in the diagnostic mode, causes an operation to be performed in which charging and exposure of an image carrier are performed under conditions different from those in the normal mode, and finally causes an operation to be performed in which charging and exposure of an image carrier are performed under the same conditions as those in the normal mode. (((5))) The image forming apparatus described in (((4))) is characterized in that, when, during operation in the diagnostic mode, an image carrier is charged and exposed to light under conditions different from those used in operation in the normal mode to form a toner image, the processor executes the diagnostic mode after an operation of forming a toner image without charging or exposing the image carrier and before an operation under the same conditions as those used in operation in the normal mode. (((6))) A processing system comprising: an image forming apparatus as described in any one of (((1))) to (((5))); a reading device that reads the recording medium on which a toner image has been formed by the image forming apparatus; a display device that displays an image of the recording medium read by the reading device; a reception device that receives input of an evaluation result of the image displayed on the display device; and a diagnosis device that diagnoses a condition of the image forming apparatus based on the evaluation result received by the reception device. (((7))) The processing system described in (((6))) is characterized in that the reading device reads the recording medium in the reverse order to the order in which it was output by the image forming device, and the display device displays the images of the recording medium in the order in which they were read by the reading device. (((8))) A program for controlling the computer of an image forming apparatus including an image forming unit having a function of transferring a toner image formed on an image holder by an electrophotographic method to a recording medium and forming a toner image without charging or exposing the image holder, and a computer for controlling the operation of the image forming unit, the program causing the computer to perform a process of forming a toner image without charging or exposing the image holder, and then to perform a process of charging and exposing the image holder to form a toner image, when the image forming unit is to perform a plurality of operations with different conditions regarding charging and exposing the image holder.

[0086] According to the invention (((1))), it is possible to suppress contamination inside the machine and the occurrence of BCO, compared to a configuration in which a toner image that is not charged or exposed to light is formed last. According to the invention (((2))), in-machine contamination and the occurrence of BCO can be suppressed, compared to a configuration in which a toner image that is not charged or exposed to light is formed last. According to the invention (((3))), it is possible to suppress contamination inside the machine and the generation of BCO, compared to a configuration in which a toner image that is not charged is formed last. According to the invention of (((4))), compared to a configuration in which a toner image that is not charged or exposed is formed last, an image is formed last under the same conditions as in the normal mode, making it possible to suppress in-machine contamination and the occurrence of BCO. According to the invention of (((5))), compared to a configuration in which a toner image is formed last under conditions different from operation in normal mode, image formation is performed last under the same conditions as in normal mode, making it possible to suppress in-machine contamination and the occurrence of BCO. According to the invention of ((6)), the condition of the image forming apparatus can be diagnosed based on images output by changing the conditions related to charging and exposure. According to the invention of ((7))), by first displaying the image formed by charging and exposing, it is possible to identify and evaluate a portion of the image that is of interest. According to the invention (((8))), in-machine contamination and the occurrence of BCO can be suppressed compared to a configuration in which a toner image that is not charged or exposed to light is formed last. [Explanation of symbols]

[0087] 1... processing system, 2... image forming apparatus, 3... information processing apparatus, 10... housing, 20... image forming section, 21... photosensitive drum, 22... charging device, 23... exposure device, 24... developing device, 25... primary transfer roll, 26... drum cleaner, 30... intermediate transfer belt, 40... secondary transfer roll, 50... belt cleaner, 60... paper feed section, 70... fixing device, 80... display device, 90... control device, 100... image reading device

Claims

1. an image forming unit that transfers a toner image formed on an image carrier by an electrophotographic method onto a recording medium; one or more processors for controlling operation of the image forming unit; the processor, when causing the image forming unit to execute a plurality of operations with different conditions related to charging and exposure, including at least an operation of forming a toner image by charging and exposing an image carrier and an operation of forming a toner image without charging and exposing an image carrier, causes the processor to later execute an operation of forming a toner image by charging and exposing; An image forming apparatus comprising:

2. The processor, When the operations to be executed by the image forming unit include an operation of forming a toner image by charging and exposing an image carrier and an operation of charging an image carrier and forming a toner image without exposing the image carrier, executing the operation of forming a toner image by charging and exposing the image later; 2. The image forming apparatus according to claim 1,

3. When the operations to be executed by the processor in the image forming unit include an operation of forming a toner image without charging and exposing an image carrier, and an operation of charging an image carrier and forming a toner image without exposing the image carrier, the operation of charging and forming a toner image without exposing the image carrier is executed later; 3. The image forming apparatus according to claim 2 .

4. the image forming unit is operable in a normal mode for normal image output and a diagnosis mode for diagnosing the image forming unit as an operation for forming a toner image, the processor, in the operation in the diagnostic mode, executes an operation of forming a toner image on an image carrier under charging and exposure conditions different from those in a normal mode, and finally executes an operation of forming a toner image on an image carrier under charging and exposure conditions the same as those in the normal mode; 2. The image forming apparatus according to claim 1,

5. The processor, In the operation in the diagnostic mode, when a toner image is formed by charging and exposing an image carrier under conditions different from those in the operation in the normal mode, the diagnostic mode is executed after an operation of forming a toner image without charging or exposing an image carrier and before an operation under the same conditions as those in the operation in the normal mode.

5. The image forming apparatus according to claim 4,

6. An image forming apparatus according to any one of claims 1 to 5, a reading device that reads the recording medium on which a toner image is formed by the image forming device; a display device that displays an image of the recording medium read by the reading device; a reception device that receives an input of an evaluation result of the image displayed on the display device; a diagnostic device that diagnoses a state of the image forming apparatus based on the evaluation result received by the reception device; A processing system comprising:

7. the reading device reads the recording medium in a reverse order to the order in which the recording medium was output by the image forming device; the display device displays the images of the recording medium in the order in which they were read by the reading device; The processing system according to claim 6 .

8. an image forming section that has a function of transferring a toner image formed on an image carrier by an electrophotographic method onto a recording medium and forming a toner image without charging or exposing the toner image to light; A computer that controls the operation of the image forming unit; A program for controlling the computer of an image forming apparatus comprising: The computer includes: When the image forming unit is caused to execute a plurality of operations with different conditions regarding charging and exposure of the image carrier, A process of forming a toner image on an image carrier without charging and exposing the image carrier to light is performed; Thereafter, the program causes the image carrier to be charged and exposed to light to form a toner image.

Images