Image forming apparatus, drum cartridge, and control method for image forming apparatus

Abstract

To provide an image forming apparatus that can appropriately address the degree of deterioration of a drum cartridge and cause a cleaning roller to perform a cleaning operation at a more appropriate frequency, a drum cartridge, and a method for controlling an image forming apparatus.SOLUTION: An image forming apparatus (1) is provided with: a controller (101); and drum cartridges (51) each including a photoreceptor drum, a cleaning roller, and a drum memory (51M) that can store at least either one of drum deterioration information representing the state of deterioration of the photoreceptor drum or roller deterioration information representing the state of deterioration of the cleaning roller. The controller (101) executes determination processing of determining the frequency of the cleaning operation for the photoreceptor drum executed by the cleaning roller based on the drum deterioration information or the roller deterioration information stored in the drum memory (51M).SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] This disclosure relates to an image forming apparatus, a drum cartridge, and a method for controlling the image forming apparatus. [Background technology]

[0002] Image forming apparatuses such as electrophotographic printers are equipped with drum cartridges. A drum cartridge includes, for example, a photosensitive drum and a cleaning member for cleaning the photosensitive drum. Patent Document 1 describes a drum cartridge that uses a cleaning roller that contacts the photosensitive drum as the cleaning member. Patent Document 1 also describes counting the number of dots for forming a toner image on the photosensitive drum. Furthermore, Patent Document 1 proposes performing a cleaning operation using the cleaning roller based on the result of the dot count. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2021-51139 [Overview of the project] [Problems that the invention aims to solve]

[0004] In image forming apparatuses like the one described above, deterioration occurs in the photoreceptor drum and cleaning roller of the drum cartridge with use. Therefore, a challenge for conventional image forming apparatuses and drum cartridges is to ensure that the cleaning operation by the cleaning roller is performed at a more appropriate frequency in order to adequately address the degree of deterioration in the drum cartridge.

[0005] The purpose of this disclosure is to provide an image forming apparatus, a drum cartridge, and a control method for the image forming apparatus that can appropriately respond to the degree of deterioration of the drum cartridge and allow the cleaning operation by the cleaning roller to be performed at a more appropriate frequency. [Means for solving the problem]

[0006] To solve the above problems, the image forming apparatus of the present disclosure includes a controller and a drum cartridge comprising a photoreceptor drum, a cleaning roller that contacts the surface of the photoreceptor drum, and a memory capable of storing at least one of drum deterioration information representing the deterioration state of the photoreceptor drum or roller deterioration information representing the deterioration state of the cleaning roller, wherein the controller performs a determination process to determine the frequency of performing a cleaning operation of the photoreceptor drum by the cleaning roller based on the drum deterioration information or roller deterioration information stored in the memory.

[0007] According to the above configuration, the drum cartridge has a photoreceptor drum, a cleaning roller, and memory. The memory stores at least one of drum degradation information representing the degradation state of the photoreceptor drum and roller degradation information representing the degradation state of the cleaning roller. The controller performs a decision process to determine the frequency of the cleaning operation based on the drum degradation information or roller degradation information stored in the memory. This allows the cleaning operation by the cleaning roller to be performed at a more appropriate frequency, appropriately corresponding to the degree of degradation in the drum cartridge.

[0008] In the image forming apparatus of this disclosure, the drum degradation information may be information representing the degradation state of the photoreceptor drum, defined by the cumulative number of rotations of the photoreceptor drum.

[0009] According to the above configuration, the drum degradation information is defined by the cumulative number of rotations and represents the degradation state of the photoreceptor drum, so the drum degradation information of the photoreceptor drum can be appropriately determined. As a result, the controller can reliably determine the appropriate frequency for performing the cleaning operation.

[0010] In the image forming apparatus of this disclosure, the drum degradation information may be information representing the degradation state of the photoreceptor drum, defined by the cumulative number of rotations of the photoreceptor drum and the allowable total number of rotations.

[0011] According to the above configuration, the drum degradation information is defined by the cumulative number of rotations and the allowable total number of rotations, representing the degradation state of the photoreceptor drum. Therefore, the drum degradation information of the photoreceptor drum can be appropriately determined. As a result, the controller can reliably determine the appropriate frequency for performing the cleaning operation.

[0012] In the image forming apparatus of this disclosure, the roller deterioration information may be information representing the deterioration state of the cleaning roller, defined by the cumulative number of rotations of the cleaning roller.

[0013] According to the above configuration, the roller deterioration information is defined by the cumulative number of rotations and represents the deterioration state of the cleaning roller, so the roller deterioration information of the cleaning roller can be appropriately determined. As a result, the controller can reliably determine the appropriate frequency for performing the cleaning operation.

[0014] In the image forming apparatus of this disclosure, the roller deterioration information may be information representing the deterioration state of the cleaning roller, defined by the cumulative number of rotations of the cleaning roller and the allowable total number of rotations.

[0015] According to the above configuration, the roller deterioration information is defined by the cumulative number of rotations and the allowable total number of rotations, representing the deterioration state of the cleaning roller. Therefore, the roller deterioration information of the cleaning roller can be appropriately determined. As a result, the controller can reliably determine the appropriate frequency for performing the cleaning operation.

[0016] In the image forming apparatus of the present disclosure, when the controller receives an instruction for image forming processing, it may obtain at least one of the rotation speed of the photoreceptor drum or the rotation speed of the cleaning roller according to the content of the received instruction, and perform an update process to update the drum deterioration information or the roller deterioration information stored in the memory based on the obtained rotation speed of the photoreceptor drum or the rotation speed of the cleaning roller.

[0017] According to the above configuration, drum degradation information or roller degradation information stored in memory is updated according to the content of the image formation processing instructions. As a result, the controller can more appropriately determine the frequency of performing the cleaning operation.

[0018] In the image forming apparatus of this disclosure, the controller may sequentially execute the update process and the determination process upon receiving an instruction for image forming processing.

[0019] According to the above configuration, the controller updates drum degradation information or roller degradation information before performing a decision. As a result, the controller can more reliably determine the appropriate frequency for performing cleaning operations.

[0020] The image forming apparatus of the present disclosure further comprises a humidity sensor for measuring humidity, and the controller may perform the determination process using the detection result of the humidity sensor in addition to the drum deterioration information or the roller deterioration information.

[0021] According to the above configuration, since the controller executes the determination process using the detection result of the humidity sensor in addition to the drum deterioration information or the roller deterioration information, the controller can more accurately determine the appropriate frequency of performing the cleaning operation.

[0022] In the image forming apparatus of the present disclosure, in the determination process, the controller discriminates that a first life value representing the remaining life of the photosensitive drum obtained from the drum deterioration information or a second life value representing the remaining life of the cleaning roller obtained from the roller deterioration information is equal to or greater than a threshold value. Further, when it is discriminated that the detection result of the humidity sensor is equal to or greater than a first humidity threshold value, the frequency of performing the cleaning operation may be increased.

[0023] According to the above configuration, when the life of the photosensitive drum or the cleaning roller is relatively long and the humidity is relatively high, the frequency of performing the cleaning operation becomes high. Thereby, paper dust can be efficiently collected by the cleaning roller, and adhesion of paper dust to the photosensitive drum can be suppressed.

[0024] In the image forming apparatus of the present disclosure, in the determination process, when the controller does not discriminate that the first life value or the second life value is equal to or greater than the threshold value, and when it is discriminated that the detection result of the humidity sensor is less than a second humidity threshold value, the frequency of performing the cleaning operation may be increased.

[0025] According to the above configuration, when the life of the photosensitive drum or the cleaning roller is relatively short and the humidity is relatively low, the frequency of performing the cleaning operation becomes high. Thereby, toner on the cleaning roller can be efficiently discharged, and generation of remaining toner on the cleaning roller can be suppressed.

[0026] The image forming apparatus of the present disclosure comprises a plurality of drum cartridges and a fixing unit arranged sequentially along a predetermined direction, and the controller may set the frequency of performing the cleaning operation on the drum cartridge located at the uppermost position in the predetermined direction to be higher than the frequency of performing the cleaning operation on the other drum cartridges.

[0027] With the above configuration, when performing image formation processing, paper dust can be efficiently collected by the cleaning roller of the upstream drum cartridge. As a result, the deterioration of image quality can be suppressed.

[0028] In the image forming apparatus of the present disclosure, the controller may perform the following operations by causing the cleaning operation: a toner discharge operation from the cleaning roller to the photoreceptor drum and a paper dust collection operation from the photoreceptor drum to the cleaning roller.

[0029] The above configuration simultaneously suppresses the generation of residual toner on the cleaning roller and the adhesion of paper dust on the photoreceptor drum. As a result, image quality and reliability in the image forming apparatus can be improved.

[0030] The image forming apparatus disclosed herein further comprises a main body housing and a toner cartridge having a developing roller, wherein the drum cartridge is used together with the toner cartridge and may be mounted in the main body housing together with the toner cartridge.

[0031] With the above configuration, since both the drum cartridge and the toner cartridge are used, the replacement of these drum cartridges and toner cartridges can be easily performed.

[0032] In the image forming apparatus disclosed herein, the drum cartridge and the toner cartridge may be detachably attached to and detached from the main body housing independently of each other.

[0033] According to the above configuration, an image forming apparatus can be configured in which the drum cartridge and toner cartridge can be replaced separately.

[0034] In the image forming apparatus of this disclosure, the cleaning roller may clean the surface by contacting the surface.

[0035] According to the above configuration, the cleaning roller can clean the surface of the photoreceptor drum by contacting the surface of the photoreceptor drum.

[0036] In the image forming apparatus of this disclosure, the cleaning roller may recover any deposits on the surface by cleaning the surface.

[0037] With the above configuration, the cleaning roller can collect deposits from the surface of the photoreceptor drum.

[0038] The control method for an image forming apparatus according to the present disclosure is a control method for an image forming apparatus comprising a drum cartridge having a photoreceptor drum, a cleaning roller that contacts the surface of the photoreceptor drum, and a memory, comprising: a reading step of reading drum deterioration information representing the deterioration state of the photoreceptor drum or roller deterioration information representing the deterioration state of the cleaning roller from the memory; and a determination step of determining the frequency of performing a cleaning operation of the photoreceptor drum by the cleaning roller based on the read drum deterioration information or roller deterioration information.

[0039] According to the above configuration, in the reading process, drum degradation information representing the degradation state of the photoreceptor drum or roller degradation information representing the degradation state of the cleaning roller is read from the memory. In the determination process, the frequency of the cleaning operation of the photoreceptor drum by the cleaning roller is determined based on the read drum degradation information or roller degradation information. This allows the cleaning operation by the cleaning roller to be performed at a more appropriate frequency in accordance with the degree of degradation of the drum cartridge.

[0040] The drum cartridge of this disclosure is a drum cartridge comprising: a photoreceptor drum; a cleaning roller that contacts the surface of the photoreceptor drum; and a memory that stores at least one of drum deterioration information representing the deterioration state of the photoreceptor drum or roller deterioration information representing the deterioration state of the cleaning roller, wherein the drum deterioration information or the roller deterioration information is information for determining the frequency of performing a cleaning operation of the photoreceptor drum by the cleaning roller.

[0041] According to the above configuration, the memory stores information for determining the frequency of cleaning the photoreceptor drum by the cleaning roller, and stores at least one of drum degradation information representing the degradation state of the photoreceptor drum and roller degradation information representing the degradation state of the cleaning roller. This makes it possible to perform a decision process to determine the frequency of cleaning the photoreceptor drum by the cleaning roller based on the drum degradation information or roller degradation information, thereby configuring a drum cartridge that can determine an appropriate frequency for performing the cleaning operation. [Effects of the Invention]

[0042] According to one aspect of this disclosure, it is possible to provide an image forming apparatus, a drum cartridge, and a control method for the image forming apparatus that can appropriately respond to the degree of deterioration of the drum cartridge and cause the cleaning operation by the cleaning roller to be performed at a more appropriate frequency. [Brief explanation of the drawing]

[0043] [Figure 1] This is a schematic diagram illustrating the configuration of an image forming apparatus according to one embodiment of the present disclosure. [Figure 2] This is a block diagram showing the functional blocks of the image forming apparatus described above. [Figure 3] This figure shows the details of the drum cartridge information shown in Figure 2. [Figure 4]This figure shows the details of the toner cartridge information shown in Figure 2. [Figure 5] (A) is a diagram illustrating the toner collection operation by the cleaning roller shown in Figure 1 during the image forming process, and (B) is an enlarged view of the area enclosed by rectangle VB in Figure 5(A). [Figure 6] (A) is a diagram illustrating the paper dust removal operation during the image forming process, where paper dust is removed from the cleaning roller, and (B) is an enlarged view of the area enclosed by rectangle VIB in Figure 6(A). [Figure 7] This is a flowchart illustrating the main operating examples of the image forming apparatus described above. [Figure 8] This is a flowchart illustrating a specific example of the operation of the image forming apparatus described above. [Figure 9] (A) is a diagram illustrating the cleaning operation by the cleaning roller described above, and (B) is an enlarged view of the area enclosed by rectangle IXB in Figure 9(A). [Figure 10] This diagram illustrates the specific effects of the process for determining the cleaning operation using the cleaning roller described above. [Figure 11] This figure illustrates the specific effects of the process for determining the cleaning operation by the cleaning roller in the modified example 1. [Modes for carrying out the invention]

[0044] <Configuration of Image Forming Apparatus 1> Figure 1 is a schematic diagram illustrating the configuration of an image forming apparatus 1 according to one embodiment of the present disclosure. In this embodiment, as an example of the image forming apparatus 1, the case of an LED printer that performs image forming processing of full-color images will be described.

[0045] As shown in Figure 1, the image forming apparatus 1 comprises a paper feeding unit 20, an image forming unit 30, and a paper discharge unit 90 within a main housing 10. The paper feeding unit 20 supplies paper P. The image forming unit 30 forms an image on the fed paper P. The paper discharge unit 90 discharges the paper P on which the image has been formed. Furthermore, the image forming apparatus 1 includes a main board 100 that controls each part when forming an image. The main board 100 is equipped with a controller 101 for controlling each part.

[0046] The image forming apparatus 1 includes an upper cover 11. The upper cover 11 is located on the upper part of the main body housing 10. The upper cover 11 is provided so as to be able to rotate up and down with a pivot shaft 12 as the pivot point. The upper cover 11 opens and closes an opening provided in the main body housing 10. The upper surface of the upper cover 11 functions as a paper output tray 13. The paper output tray 13 stores the paper P discharged from the main body housing 10. In addition, a plurality of holding members 14 are provided on the lower surface of the upper cover 11. The plurality of holding members 14 hold the LED unit 40, which is an exposure device. Inside the upper cover 11, there is an LED control board 110 and a shield plate 120 facing the LED control board 110.

[0047] The paper feeding unit 20 comprises a paper feeding tray 21 and a paper supply mechanism 22. The paper feeding tray 21 is located in the lower part of the main body housing 10. The paper feeding tray 21 is detachably attached to the main body housing 10. The paper supply mechanism 22 comprises a paper feeding roller 23, a separation roller 24, and a separation pad 25. The paper supply mechanism 22 is located on the front side of the paper feeding tray 21. The paper supply mechanism 22 transports the paper P from the paper feeding tray 21 to the image forming unit 30.

[0048] In the paper feeding unit 20, the paper sheets P in the paper tray 21 are separated one by one and fed upward. Then, in the paper feeding unit 20, paper dust is removed as the paper passes between the paper dust removal roller 26 and the pinch roller 27. After that, the paper sheets P are turned backward through the transport path 28. After that, the paper sheets P are supplied to the image forming unit 30.

[0049] The image forming unit 30 comprises four process cartridges 50, four LED units 40, a belt unit 70, and a fixing unit 80.

[0050] The LED unit 40 comprises an LED print head 41 and a support frame 42. The LED print head 41 is positioned above the photoreceptor drum 53 and opposite the photoreceptor drum 53.

[0051] The support frame 42 is a component that supports the LED print head 41. The support frame 42 is pivotably attached to the upper cover 11 via the holding member 14. As a result, the LED unit 40 (LED print head 41) moves from the exposure position facing the photoreceptor drum 53 to an upward retracted position by rotating the upper cover 11 upward.

[0052] The process cartridge 50 is arranged in a front-to-back direction between the upper cover 11 and the paper feed section 20. The process cartridge 50 comprises a drum cartridge 51 and a toner cartridge 60. This process cartridge 50 can be replaced through an opening in the main body housing 10 after rotating the upper cover 11 upward. In other words, in the process cartridge 50, the toner cartridge 60 is used together with the drum cartridge 51 and is integrally and detachably mounted to the main body housing 10 together with the drum cartridge 51. Furthermore, in the process cartridge 50, the drum cartridge 51 and the toner cartridge 60 are configured to be separable from each other.

[0053] Each process cartridge 50 is identical in its configuration, differing only in the color of the toner (developer) contained in the toner storage chamber 66 of the toner cartridge 60.

[0054] The drum cartridge 51 comprises a drum frame 52, a photoreceptor drum 53, and a charger 54. The photoreceptor drum 53 is rotatably supported on the drum frame 52. The charger 54 is, for example, a scorotron-type charger or a charger having charging rollers.

[0055] Furthermore, the drum cartridge 51 has a cleaning roller 55 that is in constant contact with the surface of the photoreceptor drum 53. The cleaning roller 55 is configured to clean the surface of the photoreceptor drum 53 by contacting it. In other words, the cleaning roller 55 is configured to remove and recover toner and paper dust, which are deposits adhering to the surface of the photoreceptor drum 53, by cleaning the surface of the photoreceptor drum 53.

[0056] Furthermore, the cleaning roller 55 is configured to perform a cleaning operation of the photoreceptor drum 53 in accordance with instructions from the controller 101. The cleaning operation here refers to the simultaneous performance of a toner discharge operation, which discharges toner from the surface of the cleaning roller 55 to the surface of the photoreceptor drum 53, and a paper dust collection operation, which collects paper dust from the surface of the photoreceptor drum 53 to the surface of the cleaning roller 55. Moreover, as will be described in detail later, the controller 101 performs the cleaning operation by applying a voltage control to the cleaning roller 55 that is different from the voltage control used during image forming processing.

[0057] The toner cartridge 60 includes a developer for developing the electrostatic latent image formed on the photoreceptor drum 53. The toner cartridge 60 comprises a developing frame 62, a developing roller 63, and a supply roller 64. The developing roller 63 and the supply roller 64 are rotatably supported on the developing frame 62. The toner cartridge 60 also includes a blade assembly 65 and a toner storage chamber 66 for storing toner.

[0058] In the above description, we have described a case in which a process cartridge 50 is used in which the drum cartridge 51 and the toner cartridge 60 are separable from each other. However, this embodiment is not limited to this, and for example, an integrated process cartridge in which the drum cartridge and the toner cartridge are not separable can also be used.

[0059] The belt unit 70 is located between the paper feed unit 20 and each process cartridge 50. The belt unit 70 comprises a drive roller 71, a driven roller 72, a transport belt 73, a transfer roller 74, and a cleaning unit 75. The belt unit 70 has a transport belt 73 positioned opposite the four process cartridges 50. The transport belt 73 functions as a transfer belt. In other words, the belt unit 70 constitutes a transfer belt unit for forming a full-color image.

[0060] The drive roller 71 and the driven roller 72 are arranged parallel to each other and spaced apart in the front-rear direction. A conveyor belt 73, which is an endless belt, is provided between the drive roller 71 and the driven roller 72. The outer surface of the conveyor belt 73 is in contact with each photoreceptor drum 53. Inside the conveyor belt 73, four transfer rollers 74 are arranged opposite each photoreceptor drum 53, sandwiching the conveyor belt 73 between them. A transfer bias, which is the transfer voltage, is applied to these transfer rollers 74 by constant current control during transfer.

[0061] The cleaning unit 75 is located below the conveyor belt 73. The cleaning unit 75 includes, for example, a cleaning roller, a recovery roller, a blade, and a toner storage unit 76. The cleaning roller contacts the conveyor belt 73. The recovery roller contacts the cleaning roller. The blade contacts the recovery roller. The toner storage unit 76 is located below the blade. As a result, in the cleaning unit 75, toner is removed from the conveyor belt 73 by the cleaning roller. Furthermore, in the cleaning unit 75, foreign matter is dropped into the toner storage unit 76 via the recovery roller and the blade. In addition to the above description, a cleaning blade or cleaning brush may be used to contact the conveyor belt 73 instead of the cleaning roller.

[0062] The fixing unit 80 is located behind each process cartridge 50 and belt unit 70. That is, the fixing unit 80 is located downstream of each process cartridge 50 and belt unit 70 in a predetermined direction from left to right in Figure 1. The fixing unit 80 includes a heating roller 81 and a pressure roller 82 which is positioned opposite the heating roller 81 and presses against it.

[0063] In the image forming unit 30 configured in this way, first, the surface of each photoreceptor drum 53 is uniformly charged by the charger 54, and then exposed by LED light irradiated from each LED print head 41. As a result, an electrostatic latent image based on image data is formed on each photoreceptor drum 53.

[0064] Furthermore, the toner in the toner storage chamber 66 is supplied to the developing roller 63 by the rotation of the supply roller 64, and by the rotation of the developing roller 63, it enters the space between the developing roller 63 and the blade assembly 65 and is carried on the developing roller 63 as a thin layer of a certain thickness.

[0065] The toner supported on the developing roller 63 is supplied to the electrostatic latent image formed on the photoreceptor drum 53 when the developing roller 63 comes into contact with the photoreceptor drum 53. As a result, the toner is selectively supported on the photoreceptor drum 53, the electrostatic latent image is made visible, and a toner image is formed by inversion development.

[0066] Then, as the paper P supplied onto the transport belt 73 passes between each photoreceptor drum 53 and each transfer roller 74 located inside the transport belt 73, the toner images formed on each photoreceptor drum 53 are sequentially transferred onto the paper P. When the paper P passes between the heating roller 81 and the pressure roller 82, the toner images transferred onto the paper P are heat-fixed.

[0067] The paper discharge section 90 includes a paper discharge side transport path 91 that extends upward from the outlet of the fuser unit 80 and is formed to invert towards the front, and a plurality of pairs of transport rollers 92 for transporting the paper P. The paper P, on which the toner image has been transferred and heat-fixed, is transported along the paper discharge side transport path 91 by the transport rollers 92, discharged to the outside of the main body housing 10, and accumulated in the paper discharge tray 13.

[0068] <Software configuration of image forming apparatus 1> Figure 2 is a block diagram showing the functional blocks of the image forming apparatus 1. The image forming apparatus 1 comprises a controller 101, a main memory 102, a humidity sensor 103, and a display 104. The image forming apparatus 1 also has connectors 201 and 202.

[0069] The connector 201 is electrically connected to the drum memory 51M provided on the drum cartridge 51. When the connector 201 and the drum memory 51M are electrically connected, the controller 101 becomes able to communicate with the drum memory 51M. That is, the controller 101 becomes able to write information to and rewrite information in the drum memory 51M, and read information from the drum memory 51M.

[0070] The drum memory 51M is a memory capable of reading and writing information. The type of drum memory 51M is not particularly limited. For example, the drum memory 51M may be flash ROM, EEPROM®, or an IC chip.

[0071] The connector 202 is electrically connected to the toner memory 60M provided in the toner cartridge 60. When the connector 202 and the toner memory 60M are electrically connected, the controller 101 becomes able to communicate with the toner memory 60M. That is, the controller 101 becomes able to write information to and rewrite information in the toner memory 60M, and read information from the toner memory 60M.

[0072] The toner memory 60M is a memory capable of reading and writing information. The type of toner memory 60M is not particularly limited. For example, the toner memory 60M may be flash ROM, EEPROM®, or an IC chip.

[0073] In addition to the above description, the belt unit 70 may be provided with a belt memory that stores predetermined belt information, and the controller 101 may read and write belt information to and from the belt memory.

[0074] <Controller 101> The controller 101 includes, for example, a CPU, RAM, ROM, and input / output circuits, and performs image formation control by performing calculations based on information from the installed cartridge and programs and data stored in the ROM. In addition, the controller 101 also performs control processing other than image formation control as appropriate, according to information acquired from each part of the image forming apparatus 1.

[0075] The controller 101 reads drum cartridge information 510 from the drum memory 51M at a predetermined timing. The controller 101 stores the read drum cartridge information 510 in the main memory 102 as drum cartridge information 1021.

[0076] The controller 101 reads the toner cartridge information 600 from the toner memory 60M at a predetermined timing. The controller 101 stores the read toner cartridge information 600 in the main unit memory 102 as toner cartridge information 1022.

[0077] The timing at which the controller 101 reads information from the drum memory 51M or the toner memory 60M is not particularly limited. For example, the controller 101 may read information from the drum memory 51M or the toner memory 60M when the drum cartridge 51 or the toner cartridge 60 is installed in the image forming apparatus 1. Alternatively, the controller 101 may read information from the drum memory 51M or the toner memory 60M when the power to the image forming apparatus 1 changes from an off state to an on state. The controller 101 may then store the read information in the main unit memory 102.

[0078] Based on the information read from the drum memory 51M, the controller 101 performs a decision process to determine the frequency of cleaning the photoreceptor drum 53 by the cleaning roller 55 contained in each drum cartridge 51. As a result of the decision process, the controller 101 also selects one of the following modes: drum sticking suppression mode, cleaning residual ghost suppression mode, or normal cleaning operation mode. Then, for each drum cartridge 51, the controller 101 causes the cleaning roller 55 to perform the cleaning operation based on the selected mode.

[0079] In addition to the above explanation, the controller 101 may also perform a decision process based on the information it reads from the drum memory 51M and stores in the main unit memory 102.

[0080] <Main unit memory 102> The main memory 102 is a memory that can read and write information. The main memory 102 is, for example, flash ROM or EEPROM (registered trademark, Electronically Erasable and Programmable Read Only Memory).

[0081] The main memory 102 stores drum cartridge information 1021, toner cartridge information 1022, device ID 1023, and page count counter 1024.

[0082] The drum cartridge information 1021 is information relating to the drum cartridge 51 installed in the image forming apparatus 1. In this embodiment, the drum cartridge information 1021 includes the same information as the drum cartridge information 510. The drum cartridge information 1021 is stored separately for each drum cartridge 51.

[0083] The toner cartridge information 1022 is information relating to the toner cartridge 60 installed in the image forming apparatus 1. In this embodiment, the toner cartridge information 1022 includes the same information as the toner cartridge information 600. The toner cartridge information 1022 is stored separately for each toner cartridge 60.

[0084] The device ID 1023 is the identification information for image forming apparatus 1. The device ID 1023 may also be, for example, the serial number of the image forming apparatus.

[0085] The sheet count counter 1024 is a counter that indicates the cumulative number of prints in the image forming apparatus 1. The sheet count counter 1024 is incremented by the controller 101 each time printing, i.e., each image forming process is performed. The sheet count counter 1024 may also be initialized according to instructions from the controller 101. Furthermore, the value of the sheet count counter 1024 may be read by the controller 101 as appropriate and transmitted to a server (not shown) via a communication unit (not shown).

[0086] In addition to the various information described above, the main memory 102 may also store images to be displayed on the display 104. Furthermore, the main memory 102 may also store a control program that implements a control method for the image forming apparatus 1.

[0087] The humidity sensor 103 is a sensor that detects the humidity outside the main unit housing 10. The humidity sensor 103 outputs the measurement result to the controller 101. Specifically, for example, when a print job is completed, the controller 101 instructs the humidity sensor 103 to detect the humidity.

[0088] The humidity sensor 103 then detects the humidity outside the main unit housing 10 at the end of the print job and outputs the detection result to the controller 101. The type of humidity sensor 103 and the output format of the detection result are not particularly limited.

[0089] Furthermore, in this embodiment, the controller 101 performs a decision process using the detection result of the humidity sensor 103, specifically the detected humidity, in addition to the drum deterioration information or roller deterioration information (details will be described later).

[0090] In addition to the above explanation, for example, a humidity sensor may be provided to detect the humidity inside the main unit housing 10, and the controller 101 may perform a decision process using the results of the humidity detection from this humidity sensor. In this case, a temperature and humidity sensor capable of detecting both the humidity and temperature inside the main unit housing 10 can be used.

[0091] The display 104 is an output interface capable of displaying characters and images. An example of the display 104 is a liquid crystal display. The display surface of the display 104 may be located on the outer surface of the main body housing 10 so that the user of the image forming apparatus 1 can easily see the information displayed on the display surface. The display 104 displays images input from the controller 101 on its display surface.

[0092] Furthermore, the display 104 in this embodiment is equipped with a touch panel function, and the display 104 constitutes an operation reception unit that receives user operation instructions, such as print job instructions, i.e., instructions for image formation processing.

[0093] In addition to the above description, the operation reception unit may also include, for example, at least one of the operation buttons (not shown) located near the display 104 and a communication unit (not shown) that receives instruction data from an external source online.

[0094] <Drum Cartridge Information 510> Figure 3 shows the details of the drum cartridge information 510 shown in Figure 2. The drum memory 51M stores, as drum cartridge information 510, at least drum deterioration information 513 representing the deterioration state of the photoreceptor drum 53 and roller deterioration information 514 representing the deterioration state of the cleaning roller 55. The drum memory 51M may also store drum ID 511, drum specification information 512, and print count 515 as drum cartridge information 510.

[0095] The drum degradation information 513 is information that represents the degradation state of the photoreceptor drum 53, defined, for example, by the cumulative number of rotations 513A of the photoreceptor drum 53 and the total number of rotations 513B that is permitted for the photoreceptor drum 53.

[0096] The cumulative rotation count 513A represents the cumulative rotation count of the photoreceptor drum 53 since the start of use of the drum cartridge 51. The allowable total rotation count 513B represents the remaining usable rotation count of the photoreceptor drum 53 at the present time. In other words, the allowable total rotation count 513B is the value obtained by subtracting the value of the cumulative rotation count 513A from the predetermined life rotation count value for the photoreceptor drum 53. The controller 101 may perform a determination process using the first life value, described later, which represents the remaining life of the photoreceptor drum 53 and is obtained from the drum degradation information 513.

[0097] The roller deterioration information 514 is information that represents the deterioration state of the cleaning roller 55, defined, for example, by the cumulative number of rotations 514A of the cleaning roller 55 and the total number of rotations 514B that are permitted for the cleaning roller 55.

[0098] The cumulative rotation count 514A represents the cumulative rotation count of the cleaning roller 55 since the start of use of the drum cartridge 51. The allowable total rotation count 514B represents the remaining usable rotation count of the cleaning roller 55 at the present time. In other words, the allowable total rotation count 514B is the value obtained by subtracting the value of the cumulative rotation count 514A from the predetermined life rotation count value for the cleaning roller 55. The controller 101 may perform a decision process using the second life value, described later, which represents the remaining life of the cleaning roller 55 and is obtained from the roller deterioration information 514.

[0099] In addition to the above explanation, for example, the drum memory 51M may store the cumulative rotation speeds 513A and 514A, and the main unit memory 102 may store the total allowable rotation speeds 51A and 514B.

[0100] Drum ID 511 is identification information for drum cartridge 51. Drum specification information 512 may include one or more of the following: type, size, shape of photoreceptor drum 53, material of photoreceptor, degree of wearability of photoreceptor drum 53, and parameters for determining rotational speed or rotations per unit time. Print count 515 is information indicating the number of prints since the start of use of drum cartridge 51.

[0101] The various pieces of information in the drum cartridge information 510 listed above are merely examples of the information that may be included in the drum cartridge information 510. The drum cartridge information 510 may also include other information besides the various pieces of information mentioned above. Furthermore, some of the various pieces of information in the drum cartridge information 510 mentioned above may be omitted as appropriate.

[0102] <Toner Cartridge Information 600> Figure 4 shows the details of the toner cartridge information 600 shown in Figure 2. The toner memory 60M stores at least the cumulative dot count 604 and the cumulative rotation count of the developer roller 605 as toner cartridge information 600. The toner memory 60M may also store the toner ID 601, capacity information 602, toner cartridge specification information 603, and the number of printed pages 606 as toner cartridge information 600.

[0103] Toner ID 601 is the identification information for toner cartridge 60. Capacity information 602 indicates the toner capacity in toner cartridge 60. In other words, capacity information 602 indicates the amount of toner filled in toner cartridge 60 when it is new.

[0104] The toner cartridge specification information 603 contains information regarding the specifications of the developing roller 63 and the toner. The specifications of the developing roller 63 refer to one or more of the following: the type, size, shape, material, characteristics, and various setting values ​​of the developing roller 63. The specifications of the toner refer to one or more of the following: the average particle size, circularity, material, characteristics, and various setting values ​​of the toner. In this embodiment, the toner cartridge specification information 603 includes the type of developing roller 63 and parameters for determining the rotation speed of the developing roller 63. The parameters for determining the rotation speed of the developing roller 63 may be predetermined based on the various specifications of the developing roller 63.

[0105] The cumulative dot count of 604 is the cumulative number of dots printed since the start of use of toner cartridge 60. The cumulative developer roller rotation count of 605 is the cumulative number of rotations of the developer roller 63 since the start of use of toner cartridge 60. Toner is a consumable item, and the developer roller 63 also deteriorates with rotation. Therefore, the cumulative dot count of 604 and the cumulative developer roller rotation count of 605 can be said to be information indicating the lifespan of toner cartridge 60. The number of printed pages of 606 is information indicating the number of pages printed since the start of use of toner cartridge 60.

[0106] The various pieces of information in the toner cartridge information 600 listed above are merely examples of the information that may be included in the toner cartridge information 600. The toner cartridge information 600 may also include other information besides the various pieces of information mentioned above. Furthermore, some of the various pieces of information in the toner cartridge information 600 mentioned above may be omitted as appropriate.

[0107] <Operation of Image Forming Apparatus 1> The operation of the image forming apparatus 1 of this embodiment will be described in detail below. In the following description, the operation of the cleaning roller 55 in contact with the photoreceptor drum 53 during the image forming process will be explained using Figures 5 and 6.

[0108] <Toner recovery operation by cleaning roller 55> First, the toner recovery operation by the cleaning roller 55 will be explained in detail using Figures 5(A) and 5(B). Figure 5(A) is a diagram illustrating the toner recovery operation by the cleaning roller 55 shown in Figure 1 during image formation processing, and Figure 5(B) is an enlarged view of the area enclosed by rectangle VB in Figure 5(A).

[0109] In the following explanation, the operation of the cleaning roller 55 included in the drum cartridge 51 located at the uppermost position in a predetermined direction among the four drum cartridges 51 will be used as an example (the same applies to Figures 6(A) and 9(A) shown later). Also, in the following explanation, when the image forming apparatus 1 is in operation, for example, the polarity of charge on the toner will be considered positive, and the polarity of charge on the paper dust will be considered negative.

[0110] As shown in Figure 5(A), when the image forming apparatus 1 is performing an image forming process, the photoreceptor drum 53, cleaning roller 55, developing roller 63, and transfer roller 74 rotate in the directions indicated by arrows R1, R2, R3, and R4, respectively. The transport belt 73, with a sheet of paper P (not shown) on it, transports it in the predetermined direction indicated by arrow H in Figure 5(A).

[0111] Furthermore, a paper dust collection chamber R for collecting paper dust is provided near the cleaning roller 55. The paper dust collection chamber R comprises a collection shaft RS and a collection box RB. The collection shaft RS is configured to contact the surface of the cleaning roller 55. The controller 101 controls the power supply of the image forming apparatus 1 so that the collection shaft RS is at a positive potential when the image forming apparatus 1 is operating, thereby applying a voltage of -100V to the collection shaft RS, for example, so that the potential difference with respect to the cleaning roller 55 is +200V.

[0112] Furthermore, when the image forming apparatus 1 is performing image forming processing, the surface potential V of the cleaning roller 55 CLN The surface potential V of the photoreceptor drum 53 LThe controller 101 controls the power supply of the image forming apparatus 1 so that the potential is lower than (=+150V). Specifically, as shown in Figure 5(A), the controller 101 controls the surface potential V of the cleaning roller 55. CLN By controlling the power supply of the image forming apparatus 1 so that the voltage becomes negative, a voltage of, for example, -300V is applied to the cleaning roller 55.

[0113] As a result, during the toner recovery operation by the cleaning roller 55, an electric field is generated in the direction from the photoreceptor drum 53 towards the cleaning roller 55, as shown by arrow E in Figure 5(B). Consequently, as shown in Figure 5(B), of the positively charged toner T and the negatively charged paper dust, only the toner T is attracted from the surface of the photoreceptor drum 53 to the surface of the cleaning roller 55 and recovered by the cleaning roller 55.

[0114] In other words, when the image forming apparatus 1 is performing an image forming process, the cleaning roller 55 contacts the surface of the photoreceptor drum 53 and cleans the surface, thereby recovering toner T from the surface of the photoreceptor drum 53. As a result, the transfer of unwanted toner T to the paper P in the next image forming process is suppressed, thereby reducing the occurrence of image quality degradation during the image forming process.

[0115] <Paper dust removal operation from cleaning roller 55> Next, the paper dust removal operation, which removes paper dust from the cleaning roller 55, will be specifically explained using Figures 6(A) and 6(B). Figure 6(A) is a diagram illustrating the paper dust removal operation during the image forming process, and Figure 6(B) is an enlarged view of the area enclosed by rectangle VIB in Figure 6(A). This paper dust removal operation is performed by the controller 101 simultaneously when, for example, the image forming process exemplified in Figure 5(A) is executed.

[0116] As shown in Figure 6(A), when the controller 101 performs the paper dust removal operation, the controller 101 controls the surface potential V of the cleaning roller 55. CLNThe controller 101 controls the power supply of the image forming apparatus 1 so that the potential of the surface potential of the cleaning roller 55 is lower than the potential of the recovery shaft RS. Specifically, the controller 101 controls the power supply of the image forming apparatus 1 so that the potential of the recovery shaft RS becomes positive during the paper dust removal operation, for example, by applying a voltage of -100V to the recovery shaft RS so that the potential difference with respect to the cleaning roller 55 is +200V. On the other hand, as shown in Figure 6(A), the controller 101 controls the surface potential V of the cleaning roller 55. CLN By controlling the power supply of the image forming apparatus 1 so that the voltage becomes negative, a voltage of, for example, -300V is applied to the cleaning roller 55.

[0117] As a result, during the paper dust removal operation from the cleaning roller 55, an electric field is generated in the direction from the photoreceptor drum 53 towards the cleaning roller 55, as shown by arrow E in Figure 5(B). This causes only the toner T to be drawn from the surface of the photoreceptor drum 53 to the surface of the cleaning roller 55 and collected by the cleaning roller 55, similar to the toner T recovery operation shown in Figure 5(B). Meanwhile, as shown in Figure 6(B), the paper dust K is drawn from the surface of the cleaning roller 55 to the surface of the recovery shaft RS. Furthermore, the paper dust K is collected from the surface of the recovery shaft RS into the recovery box RB and removed from the surface of the recovery shaft RS.

[0118] Next, with reference to Figures 7 and 8, we will specifically describe the operation examples of the image forming apparatus 1 of this embodiment. Figure 7 is a flowchart illustrating the main operation examples of the image forming apparatus 1. Figure 8 is a flowchart illustrating a specific operation example of the image forming apparatus 1.

[0119] <Examples of main operations of the image forming apparatus 1> As shown in step S1 of Figure 7, the controller 101 determines whether or not the operation reception unit has received a print job. In other words, the controller 101 determines, for example, whether or not the touch panel on the display 104 has received an instruction for image formation processing as a print job. If the controller 101 determines that it has not received an instruction (NO in step S1), the controller 101 enters a standby state.

[0120] On the other hand, when the controller 101 determines that it has received an instruction (YES in step S1), the controller 101 obtains at least one of the rotation speeds of the photoreceptor drum 53 or the cleaning roller 55, depending on the content of the received instruction.

[0121] Specifically, based on the content of the instruction, the controller 101 calculates and obtains for each drum cartridge 51 at least one of the rotation speeds of the photoreceptor drum 53 that are actually rotated by executing the received print job or the rotation speeds of the cleaning roller 55 that are actually rotated. Then, based on the obtained rotation speeds of the photoreceptor drum 53 or cleaning roller 55, the controller 101 performs an update process for each drum cartridge 51 to update the drum deterioration information 513 or roller deterioration information 514 stored in the drum memory 51M (step S2).

[0122] Specifically, the controller 101 adds the acquired rotation speed value of the photoreceptor drum 53 to the cumulative rotation speed value 513A of the drum degradation information 513, and rewrites the cumulative rotation speed value 513A to the value after the addition. The controller 101 also subtracts the acquired rotation speed value of the photoreceptor drum 53 from the allowable total rotation speed value 513B of the drum degradation information 513, and rewrites the allowable total rotation speed value 513B to the value after the subtraction.

[0123] Furthermore, the controller 101 adds the acquired value of the cleaning roller 55's rotation speed to the value of the cumulative rotation speed 514A in the roller deterioration information 514, and rewrites the value of the cumulative rotation speed 514A to the value after the addition. Also, the controller 101 subtracts the acquired value of the cleaning roller 55's rotation speed to the value of the allowable total rotation speed 514B in the roller deterioration information 514, and rewrites the value of the allowable total rotation speed 514B to the value after the subtraction.

[0124] Next, the controller 101 performs a decision process to determine the frequency of cleaning operations for each drum cartridge 51, based on the drum deterioration information 513 or roller deterioration information 514 stored in the drum memory 51M (step S3).

[0125] <Specific examples of operation of the image forming apparatus 1> Next, using Figure 8, a specific example of the operation of the image forming apparatus 1 of this embodiment 1 will be described. In the following description, the example will be that the controller 101 performs the decision process using the drum deterioration information 513 from the drum deterioration information 513 and roller deterioration information 514 of the drum cartridge information 510. As described above, the controller 101 performs the decision process for each drum cartridge 51.

[0126] As shown in step S11 of Figure 8, the controller 101 performs a read operation to read drum cartridge information 510 from the drum memory 51M. Specifically, the controller 101 reads the value of cumulative rotations 513A and the value of the allowable total rotations 513B contained in the drum degradation information 513 from the drum memory 51M. Then, the controller 101 calculates a first life value representing the remaining life of the photoreceptor drum 53, for example, the value of the drum remaining life percentage (%). Specifically, the controller 101 obtains the value of the drum remaining life percentage by dividing the value of the allowable total rotations 513B by the life rotations value for the photoreceptor drum 53 and multiplying by 100, i.e., converting it to a percentage.

[0127] Next, the controller 101 determines whether the calculated drum remaining life percentage value is above a threshold, for example, 50% (step S12). If the controller 101 determines that the drum remaining life percentage value is above the threshold (YES in step S12), the controller 101 reads the humidity detection result value from the humidity sensor 103 (step S13).

[0128] Next, the controller 101 determines whether the value of the read humidity detection result is above the first humidity threshold, for example, 60% (step S14).

[0129] <Cleaning operation in drum adhesion suppression mode> When the controller 101 determines that the humidity detection result is greater than or equal to the first humidity threshold (YES in step S14), the controller 101 selects the drum sticking suppression mode as a result of the decision process (step S15). Subsequently, the controller 101 controls each part of the image forming apparatus 1 to start the printing operation based on the print job received in step S1.

[0130] Next, the controller 101 causes the cleaning roller 55 to perform a cleaning operation every 50 sheets of paper P that have been printed, i.e., every 1st print run (step S16). During this cleaning operation, the controller 101 interrupts the printing operation and changes the voltage control to the cleaning roller 55 from the voltage control used during the printing operation.

[0131] Furthermore, the controller 101 performs a cleaning operation when the printing operation for that print job is completed.

[0132] <Cleaning operation in normal cleaning mode> On the other hand, if the controller 101 does not determine that the humidity detection result is equal to or greater than the first humidity threshold (NO in step S14), the controller 101 selects the normal cleaning operation mode as a result of the decision process (step S20). Subsequently, the controller 101 controls each part of the image forming apparatus 1 to start the printing operation based on the print job received in step S1.

[0133] Next, the controller 101 causes the cleaning roller 55 to perform a cleaning operation every second number of printed pages, for example, every 100 pages (step S21).

[0134] Furthermore, the controller 101 performs a cleaning operation when the printing operation for that print job is completed.

[0135] <Cleaning operation in cleaning ghost suppression mode> On the other hand, if the controller 101 does not determine that the calculated drum remaining life percentage value is above a threshold (NO in step S12), the controller 101 reads the humidity detection result value from the humidity sensor 103 (step S31).

[0136] Next, the controller 101 determines whether the value of the read humidity detection result is less than the second humidity threshold, for example, 20% (step S32). If the controller 101 determines that the value of the humidity detection result is less than the second humidity threshold (YES in step S32), the controller 101 selects the cleaning residual ghost suppression mode as a result of the decision process (step S33). After that, the controller 101 controls each part of the image forming apparatus 1 to start the printing operation of the print job received in step S1.

[0137] Next, the controller 101 causes the cleaning roller 55 to perform a cleaning operation every third number of prints, for example, every 50 prints (step S34).

[0138] Furthermore, the controller 101 performs a cleaning operation when the printing operation for that print job is completed.

[0139] <Cleaning operation in normal cleaning mode> On the other hand, if the controller 101 does not determine that the humidity detection result is less than the second humidity threshold (NO in step S32), the controller 101 selects the normal cleaning operation mode as a result of the decision process (step S20). Subsequently, the controller 101 performs the operation shown in step S21.

[0140] In the above explanation, the first and third print counts were set to 50 sheets each, and the second print count to 100 sheets, but this embodiment is not limited to this. It is not limited in any way as long as the first and third print counts are less than the second print count.

[0141] Furthermore, the above description described a case in which the controller 101 uses drum deterioration information 513 to determine the frequency of performing the cleaning operation. However, this embodiment is not limited to this, and the controller 101 may also use roller deterioration information 514 to determine the frequency of performing the cleaning operation.

[0142] Specifically, the controller 101 obtains a second life value representing the remaining life of the cleaning roller from the roller deterioration information 514, and determines whether the obtained second life value is above a predetermined threshold. This second life value, like the first life value, is calculated, for example, as a percentage of the roller's remaining life. Specifically, the controller 101 obtains the percentage of the roller's remaining life by dividing the allowable total rotations 514B by the life rotations value for the cleaning roller 55 and multiplying by 100, i.e., converting it to a percentage.

[0143] Next, the controller 101 determines that the second life value is above a predetermined threshold, and further determines that the detection result of the humidity sensor 103 is above the first humidity threshold, and selects the drum sticking suppression mode. Then, in the drum sticking suppression mode, the controller 101 increases the frequency of cleaning operations compared to the normal cleaning operation mode, as shown in step S16.

[0144] Furthermore, the predetermined threshold can be set to the same value as the threshold for the first lifespan value. In other words, since the deterioration state of the photoreceptor drum 53 and the deterioration state of the cleaning roller 55 are correlated, the threshold in the determination process can be set to the same value. That is, in the image forming apparatus 1, since the rotation speed of the photoreceptor drum 53 and the rotation speed of the cleaning roller 55 are correlated, the threshold for the first lifespan value and the predetermined threshold for the second lifespan value in the determination process can be set to the same value.

[0145] Furthermore, if the controller 101 does not determine that the second lifetime value is equal to or greater than a predetermined threshold, the controller 101 selects the cleaning residual ghost suppression mode when it determines that the detection result of the humidity sensor 103 is less than the second humidity threshold. Then, in the cleaning residual ghost suppression mode, the controller 101 increases the frequency of cleaning operations compared to the normal cleaning operation mode, as shown in step S34.

[0146] In the above description, the controller 101 was described in the case where the drum remaining life ratio value and the roller remaining life ratio value were used as the first life value and second life value, respectively. However, the first life value and second life value in this embodiment are not limited to these, and the drum remaining rotations and the roller remaining rotations can also be used, respectively. Here, the drum remaining rotations is the subtracted value obtained by subtracting the cumulative rotations from the life rotations of the photoreceptor drum 53, and the roller remaining rotations is the subtracted value obtained by subtracting the cumulative rotations from the life rotations of the cleaning roller 55.

[0147] In addition to the above description, the controller 101 may perform determination processing on the frequency of performing the cleaning operation using both the drum deterioration information 513 and the roller deterioration information 514.

[0148] <Toner ejection operation and paper dust collection operation by the cleaning operation> Next, referring also to FIG. 9, the cleaning operation in the present embodiment will be specifically described. FIG. 9(A) is a diagram for explaining the cleaning operation by the cleaning roller 55, and FIG. 9(B) is an enlarged view of the portion surrounded by the rectangle IXB in FIG. 9(A).

[0149] As shown in FIG. 9(A), in the cleaning operation, the controller 101 controls the power supply of the image forming apparatus 1 so that the surface potential V of the cleaning roller 55 CLN is higher than the surface potential V of the photosensitive drum 53. L Specifically, the controller 101 applies a voltage of +650 V to the recovery shaft RS so that the potential of the recovery shaft RS becomes a positive potential during the paper dust removal operation, for example, so that the potential difference from the cleaning roller 55 is +200 V. On the other hand, the controller 101 performs the cleaning operation by controlling the voltage for the cleaning roller 55 as a voltage control different from that during the image forming process.

[0150] More specifically, as shown in FIG. 9(A), the controller 101 controls the power supply of the image forming apparatus 1 so that the surface potential V of the cleaning roller 55

[0151] is higher than the surface potential V of the photosensitive drum 53 CLN (= +150 V), and applies a voltage of +450 V, for example. L (= +150 V), and applies a voltage of +450 V, for example.

[0152] As a result, during the cleaning operation by the cleaning roller 55, an electric field is generated in the direction from the cleaning roller 55 toward the photoreceptor drum 53, as indicated by arrow E in Figure 9(B). This allows the toner T to be ejected and the paper dust K to be collected simultaneously during the cleaning operation, as shown in Figure 9(B).

[0153] In other words, during the cleaning operation, the toner T is positively charged, so the toner T is attracted from the surface of the cleaning roller 55 toward the surface of the photoreceptor drum 53 by the toner T ejection operation and ejected toward the photoreceptor drum 53. The ejected toner T is then collected and stored in the toner storage unit 76 via the conveyor belt 73 from the surface of the photoreceptor drum 53.

[0154] Furthermore, during the cleaning operation, since the paper dust K is negatively charged, the paper dust K is drawn from the surface of the photoreceptor drum 53 toward the surface of the cleaning roller 55 during the paper dust K recovery operation and is recovered by the cleaning roller 55.

[0155] In other words, when the image forming apparatus 1 is performing a cleaning operation, the cleaning roller 55 contacts the surface of the photoreceptor drum 53 and cleans the surface, thereby recovering paper dust K from the surface of the photoreceptor drum 53. As a result, it is possible to suppress the adhesion of unwanted paper dust K to the paper P for the next image forming process, thereby suppressing the occurrence of image quality degradation during the image forming process.

[0156] Thus, in this embodiment, the controller 101 performs a cleaning operation, which involves both the discharge of toner T from the cleaning roller 55 to the photoreceptor drum 53 and the collection of paper dust K from the photoreceptor drum 53 to the cleaning roller 55. As a result, in this embodiment, the generation of residual toner at the cleaning roller 55 and the accumulation of paper dust K at the photoreceptor drum 53 can be simultaneously suppressed. Consequently, in this embodiment, the image quality and reliability of the image forming apparatus 1 can be improved.

[0157] <Effects and Actions> The image forming apparatus 1 of this embodiment, configured as described above, comprises a controller 101, a photoreceptor drum 53, and a cleaning roller 55. The image forming apparatus 1 of this embodiment also comprises a drum cartridge 51 equipped with a drum memory 51M capable of storing at least one of drum deterioration information 513 representing the deterioration state of the photoreceptor drum 53 or roller deterioration information 514 representing the deterioration state of the cleaning roller 55. The controller 101 performs a decision process to determine the frequency of cleaning the photoreceptor drum 53 by the cleaning roller 55 based on the drum deterioration information 513 or roller deterioration information 514 stored in the drum memory 51M. Thus, in this embodiment, the image forming apparatus 1 can be configured to perform cleaning by the cleaning roller 55 at a more appropriate frequency in response to the degree of deterioration in the drum cartridge 51.

[0158] Furthermore, in this embodiment, the drum degradation information 513 is defined by the cumulative rotation count 513A and the allowable total rotation count 513B, and represents information indicating the degradation state of the photoreceptor drum 53. Therefore, in this embodiment, the drum degradation information of the photoreceptor drum 53 can be appropriately determined. As a result, in this embodiment, the controller 101 can reliably determine the appropriate frequency for performing the cleaning operation.

[0159] Furthermore, in this embodiment, the roller deterioration information 514 is information representing the deterioration state of the cleaning roller 55, defined by the cumulative rotational speed 514A and the allowable total rotational speed 514B. Therefore, in this embodiment, the roller deterioration information of the cleaning roller 55 can be appropriately determined. As a result, in this embodiment, the controller 101 can reliably determine the appropriate frequency for performing the cleaning operation.

[0160] Furthermore, in this embodiment, as illustrated in step S2 of Figure 7, the controller 101 performs the update process, so the controller 101 can more appropriately determine the frequency of performing the cleaning operation.

[0161] Furthermore, in this embodiment, as illustrated in steps S2 and S3 of Figure 7, the controller 101 sequentially executes the update process and the decision process, so that the controller 101 can more reliably determine the appropriate frequency for performing the cleaning operation.

[0162] In the above description, as shown in Figure 7, the case in which the controller 101 performs the update process before the image forming process was described. However, this embodiment is not limited to this, and a configuration in which the update process is performed after the image forming process is also possible. However, as described above, it is preferable for the controller 101 to perform the update process before the image forming process because it is possible to more appropriately determine the frequency of the cleaning operation according to the deterioration state of the photoreceptor drum 53 or the deterioration state of the cleaning roller 55.

[0163] Furthermore, in this embodiment, the controller 101 performs a decision process using the detection result of the humidity sensor 103 in addition to the drum deterioration information 513 or roller deterioration information 514. As a result, in this embodiment, the controller 101 can determine the appropriate frequency for performing the cleaning operation with greater accuracy.

[0164] Furthermore, in this embodiment, the controller 101 selects the drum adhesion suppression mode when it determines that the first life value is above a threshold, and when it further determines that the detection result of the humidity sensor 103 is above the first humidity threshold. The controller 101 also increases the frequency of cleaning operations compared to the normal cleaning operation mode. As a result, in this embodiment, when the lifespan of the photoreceptor drum 53 or the cleaning roller 55 is relatively long and the humidity is relatively high, the cleaning operation can be performed relatively often. Consequently, in this embodiment, by selecting the drum adhesion suppression mode, paper dust can be efficiently collected by the cleaning roller 55, and the adhesion of paper dust to the photoreceptor drum 53 can be suppressed.

[0165] Furthermore, in this embodiment, the controller 101 selects the cleaning residual ghost suppression mode when it determines that the first life value is above a threshold, and also when it determines that the detection result of the humidity sensor 103 is below a second humidity threshold. The controller 101 also increases the frequency of cleaning operations compared to the normal cleaning operation mode. As a result, in this embodiment, when the lifespan of the photoreceptor drum 53 or the cleaning roller 55 is relatively short and the humidity is relatively low, the cleaning operation can be performed relatively often. As a result, in this embodiment, the toner on the cleaning roller 55 can be efficiently ejected, and the generation of residual toner on the cleaning roller 55 can be suppressed.

[0166] <Specific effects> Here, using Figure 10, we will explain the specific effects of the decision process performed by the controller 101 in this embodiment. Figure 10 is a diagram illustrating the specific effects of the decision process for the cleaning operation by the cleaning roller 55.

[0167] As shown in Figure 10, the surface condition of the photoreceptor drum 53 differs depending on the value of the drum remaining life percentage. When the drum remaining life percentage of the photoreceptor drum 53 is relatively large, the surface irregularities are relatively small and smooth, so the adhesion force of paper dust to the surface is large and paper dust adheres relatively easily.

[0168] Furthermore, in high-humidity environments, paper dust is relatively easily generated from the paper P, and the high amount of moisture present in the atmosphere increases the adhesion of the paper dust to the surface of the photoreceptor drum 53. In such high-humidity environments, if the drum remaining life percentage is high, drum sticking due to paper dust is more likely to occur.

[0169] Specifically, the drum adhesion phenomenon occurs when paper dust or toner is present on the surface of the photoreceptor drum 53, and the cleaning roller 55 presses against it, causing the attached material containing paper dust or toner to adhere to the surface of the photoreceptor drum 53. In addition, when the cleaning roller 55, which has paper dust or toner on its surface, presses against the photoreceptor drum 53, the attached material adheres to the surface of the photoreceptor drum 53.

[0170] Furthermore, drum adhesion can manifest in the image forming apparatus 1 as filming, color spots, or perforation spots. Additionally, as drum adhesion progresses and the filming level deteriorates, fogging and density unevenness become more likely to occur. Fogging refers to the phenomenon where toner adheres to areas on the paper P where it should not. Fogging occurs when the potential difference between the dark and bright areas of the photosensitive drum 53 decreases. Density unevenness refers to the density unevenness of the printed material on the paper P.

[0171] Furthermore, "color spots" refer to the localized degradation of image quality caused by toner being printed on white areas outside the printable area of ​​the paper. Additionally, as drum adhesion progresses and the level of perforation spots worsens, white areas may appear in the printed areas, resulting in localized degradation of image quality.

[0172] Furthermore, since the drum adhesion phenomenon tends to increase relatively rapidly as the photoreceptor drum 53 deteriorates, it is preferable to suppress the progression of the drum adhesion phenomenon and slow down the growth of deposits when the lifespan of the photoreceptor drum 53 is relatively long.

[0173] Therefore, in this embodiment, the controller 101 selects the drum adhesion suppression mode when, for example, the drum remaining life percentage is above a threshold of 50% and the humidity is above 60%. The controller 101 then performs cleaning operations relatively frequently. Specifically, in this embodiment, as shown in Figure 10 with a first print count of 50 sheets, the maximum number of consecutive prints before performing a cleaning operation is reduced. As a result, in this embodiment, by performing cleaning operations relatively frequently, paper dust can be efficiently collected by the cleaning roller 55, and the adhesion of paper dust to the photoreceptor drum 53 can be suppressed.

[0174] Furthermore, it is difficult to achieve 100% toner ejection efficiency in the cleaning roller 55, and the toner that is not ejected gradually accumulates in the cells of the cleaning roller 55. As a result, when the drum remaining life percentage decreases, the cells on the surface of the cleaning roller 55, for example, the semicircular cells shown in Figure 5(B), become relatively clogged with toner. In other words, as the cleaning roller 55 deteriorates, the amount of toner held in the cells on its surface decreases.

[0175] Furthermore, in low-humidity environments, residual toner is relatively likely to accumulate on the surface of the cleaning roller 55, making it relatively difficult for the cleaning roller 55 to adequately recover toner from the surface of the photoconductor drum 53. As a result, image quality degradation such as cleaning residue ghosting may occur on the paper P.

[0176] Therefore, in this embodiment, the controller 101 selects the cleaning residual ghost suppression mode when, for example, the drum remaining life percentage is less than a threshold of 50% and the humidity is less than 20%. The controller 101 then performs cleaning operations relatively frequently. Specifically, in this embodiment, as shown in Figure 10 with 50 pages for the third print run, the maximum number of consecutive prints before performing a cleaning operation is reduced. As a result, in this embodiment, by performing cleaning operations relatively frequently, the toner on the cleaning roller 55 can be efficiently ejected, and the generation of residual toner on the cleaning roller 55 can be suppressed.

[0177] Thus, in this embodiment, the controller 101 determines the frequency of the cleaning operation based on drum degradation information 513 or roller degradation information 514, thereby suppressing the occurrence of residual ghosting from cleaning. As a result, in this embodiment, the durability of the image forming apparatus 1 until image quality deteriorates can be improved, and a high-quality and highly reliable image forming apparatus 1 can be constructed.

[0178] In the above description, the controller 101 performed a determination process for each drum cartridge 51 to ensure that the cleaning operation is performed at the same frequency for all drum cartridges 51. However, this embodiment is not limited to this. For example, the controller 101 can also set the cleaning operation of the drum cartridge 51 located at the uppermost position in a predetermined direction to be performed at a higher frequency than the cleaning operation of the other drum cartridges 51 located on the fixing unit 80 side. In this case, when performing image forming processing, paper dust can be efficiently collected by the cleaning roller 55 of the uppermost drum cartridge 51. As a result, a decrease in image quality can be suppressed.

[0179] Furthermore, the image forming apparatus 1 of this embodiment comprises a main body housing 10 and a toner cartridge 60 having a developing roller 63. The drum cartridge 51 is used together with the toner cartridge 60 and is mounted in the main body housing 10 together with the toner cartridge 60. This makes it easy to replace the drum cartridge 51 and the toner cartridge 60 in this embodiment.

[0180] (Variation 1) Figure 11 is a diagram illustrating the specific effects of the process for determining the cleaning operation by the cleaning roller 55 in the modified example 1.

[0181] In Figure 11, in this modified example 1, the range of the drum remaining life percentage when the controller 101 selects the drum sticking suppression mode is expanded compared to the case of Embodiment 1. Furthermore, in this modified example 1, the range of the drum remaining life percentage when the cleaning residual ghost suppression mode is selected is also expanded.

[0182] Specifically, if the drum remaining life percentage is not only above the 50% threshold but also above the first intermediate threshold of 25% and below 50%, the controller 101 determines whether the value of the read humidity detection result is above the first humidity threshold of 60%. If the controller 101 determines that the value of the humidity detection result is above the first humidity threshold, the controller 101 selects the drum sticking suppression mode as a result of the decision process.

[0183] Then, the controller 101 causes the cleaning roller 55 to perform a cleaning operation every fourth number of printed pages, for example, every 75 pages. In this modified example 1, the controller 101 expands the range of the drum remaining life percentage when selecting the drum sticking suppression mode.

[0184] Furthermore, if the drum remaining life percentage is not only below the 50% threshold but also below the second intermediate threshold of 75% and above 50%, the controller 101 determines whether the value of the read humidity detection result is below the second humidity threshold of 20%. If the controller 101 determines that the value of the humidity detection result is below the second humidity threshold, the controller 101 selects the cleaning residual ghost suppression mode as a result of the decision process.

[0185] Then, the controller 101 causes the cleaning roller 55 to perform a cleaning operation every 5th print count, for example, every 75 prints. In this modified example 1, the controller 101 expands the range of the drum remaining life percentage when selecting the cleaning ghost suppression mode.

[0186] In the above explanation, the case where the fourth and fifth print counts are both 75 sheets was used as an example. However, this embodiment is not limited to this, and it is preferable that the fourth and fifth print counts are greater than the second print count and less than either the first or second print count, as this allows the cleaning operation to be performed appropriately.

[0187] With the above configuration, in this modified example 1, compared to the first embodiment, the controller 101 can respond appropriately to the degree of deterioration in the drum cartridge 51 and cause the cleaning operation by the cleaning roller 55 to be performed at a more appropriate frequency.

[0188] (Modification 2) The developing roller 63 in this embodiment may be provided on the toner cartridge 60 or on the drum cartridge 51, as long as it can realize the functions described in this embodiment.

[0189] (Variation 3) Furthermore, in the image forming apparatus 1, the drum cartridge 51 and the toner cartridge 60 may be independently detachable from the main body housing 10. In this case, the image forming apparatus 1 can be configured such that the drum cartridge 51 and the toner cartridge 60 can be replaced separately.

[0190] (Modification 4) Furthermore, the image forming apparatus 1 may also be an MFP (Multi-Function Printer) equipped with other functions such as a scanner or facsimile. Even if the image forming apparatus 1 is an MFP, the image forming apparatus 1 may perform the various processes described in the embodiment in the same way as the image forming apparatus 1 of the embodiment. The modified image forming apparatus 1 will have the same effects as the image forming apparatus 1 of the embodiment.

[0191] In addition to the above explanation, the drum degradation information 513 may also be defined solely by the cumulative rotation count 513A of the photoreceptor drum 53. In this case, the controller 101 may determine whether the cumulative rotation count 513A of the photoreceptor drum 53 is equal to or greater than a threshold. Based on this, the controller 101 performs a decision process to determine the frequency of performing the cleaning operation based on the cumulative rotation count 513A of the photoreceptor drum 53 stored in the drum memory 51M.

[0192] In addition to the above explanation, the drum degradation information 513 may be determined solely by the cumulative rotation count 513A of the photoreceptor drum 53, and the main unit memory 102 may store a predetermined life rotation count for the photoreceptor drum 53. In this case, after the read operation in step S11, the controller 101 may calculate a first life value based on the read cumulative rotation count 513A and the life rotation count stored in the main unit memory 102, and then execute the processing from step S12 onward. As a result, the controller 101 performs a decision process to determine the frequency of performing the cleaning operation based on the cumulative rotation count 513A of the photoreceptor drum 53 stored in the drum memory 51M.

[0193] In addition to the above description, the drum degradation information 513 may also be defined by the cumulative number of rotations 513A of the photoreceptor drum 53 and a predetermined life rotation count for the photoreceptor drum 53. In this case, the controller 101 can read the drum degradation information 513 from the drum memory 51M and then calculate the first life value in the same manner as described in Embodiment 1.

[0194] In addition to the above explanation, the cumulative number of printed pages may be used instead of the cumulative rotation count 513A. The allowable total number of printed pages may be used instead of the allowable total rotation count 513B. The lifespan of the photoconductor drum 53 may be used instead of the lifespan rotation count. Furthermore, the first lifespan value may be calculated based on the cumulative number of printed pages.

[0195] In addition to the above explanation, the roller deterioration information 514 may also be defined solely by the cumulative rotation count 514A of the cleaning roller 55. In this case, the controller 101 may determine whether the cumulative rotation count 514A of the cleaning roller 55 is above a threshold. Based on this, the controller 101 performs a decision process to determine the frequency of performing the cleaning operation based on the cumulative rotation count 514A of the cleaning roller 55.

[0196] In addition to the above explanation, the roller deterioration information 514 may be determined solely by the cumulative rotation count 514A of the cleaning roller 55, and the main unit memory 102 may store a predetermined life rotation count for the cleaning roller 55. In this case, after performing the reading process in step S11, the controller 101 may calculate a second life value based on the read cumulative rotation count 515A of the cleaning roller 55 and the life rotation count stored in the main unit memory 102, and then perform the processing from step S12 onward. As a result, the controller 101 performs a decision process to determine the frequency of performing the cleaning operation based on the cumulative rotation count 514A of the cleaning roller 55.

[0197] In addition to the above explanation, the roller degradation information 514 may also be defined by the cumulative number of rotations 514A of the cleaning roller 55 and a predetermined life rotation count for the cleaning roller 55. In this case, the controller 101 can read the roller degradation information 514 from the drum memory 51M and then calculate the second life value in the same manner as described in Embodiment 1.

[0198] In addition to the above explanation, the cumulative number of printed pages may be used instead of the cumulative rotation count 514A. Similarly, the allowable total number of printed pages may be used instead of the allowable total rotation count 514B. Furthermore, the lifespan of the cleaning roller 55 may be used instead of the lifespan rotation count. The second lifespan value may also be calculated based on the cumulative number of printed pages.

[0199] This disclosure is not limited to the embodiments described above, and various modifications are possible within the scope of the claims. Configurations obtained by appropriately combining the technical means disclosed in each embodiment are also included in the technical scope of this disclosure. [Explanation of symbols]

[0200] 1. Image forming apparatus 51 Drum Cartridge 51M Drum Memory 53 Photoconductor Drum 55 Cleaning Roller 60 Toner Cartridges 80 Fuser Unit 101 Controller 513 Drum Degradation Information 513A Cumulative rotations 513B Allowable total rotations 514 Laura deterioration information 514A Cumulative rotations 514B Allowable total rotational speed

Claims

1. Controller and A humidity sensor that measures humidity, It is a drum cartridge, Photosensitive drum and A cleaning roller that contacts the surface of the photosensitive drum, A memory capable of storing at least one of drum deterioration information representing the deterioration state of the photosensitive drum or roller deterioration information representing the deterioration state of the cleaning roller, A drum cartridge equipped with, The controller performs a determination process to determine the frequency of performing the cleaning operation of the photoreceptor drum by the cleaning roller, based on the drum deterioration information or roller deterioration information stored in the memory. In the decision process, the controller When it is determined that a first life value representing the remaining life of the photoreceptor drum obtained from the drum degradation information, or a second life value representing the remaining life of the cleaning roller obtained from the roller degradation information, is greater than or equal to a threshold, and further when it is determined that the detection result of the humidity sensor is greater than or equal to a first humidity threshold, the frequency of performing the cleaning operation is increased. An image forming apparatus that, if it is not determined that the first life value or the second life value is greater than or equal to the threshold, increases the frequency of performing the cleaning operation when it is determined that the detection result of the humidity sensor is less than the second humidity threshold.

2. The image forming apparatus according to claim 1, wherein the drum degradation information is information representing the degradation state of the photoreceptor drum, defined by the cumulative number of rotations of the photoreceptor drum.

3. The image forming apparatus according to claim 1, wherein the drum degradation information is information representing the degradation state of the photoreceptor drum, defined by the cumulative number of rotations of the photoreceptor drum and the allowable total number of rotations.

4. The image forming apparatus according to any one of claims 1 to 3, wherein the roller deterioration information is information representing the deterioration state of the cleaning roller, defined by the cumulative number of rotations of the cleaning roller.

5. The image forming apparatus according to any one of claims 1 to 3, wherein the roller deterioration information is information representing the deterioration state of the cleaning roller, defined by the cumulative number of rotations of the cleaning roller and the allowable total number of rotations.

6. The image forming apparatus according to any one of claims 1 to 5, wherein the controller, upon receiving an instruction for image forming processing, obtains at least one of the rotation speed of the photoreceptor drum or the rotation speed of the cleaning roller according to the content of the received instruction, and performs an update process to update the drum deterioration information or roller deterioration information stored in the memory based on the obtained rotation speed of the photoreceptor drum or the rotation speed of the cleaning roller.

7. The image forming apparatus according to claim 6, wherein the controller, upon receiving an instruction for image forming processing, sequentially executes the update processing and the determination processing.

8. The system comprises a plurality of drum cartridges and a fixing unit arranged sequentially along a predetermined direction, The image forming apparatus according to any one of claims 1 to 7, wherein the controller makes the frequency of performing the cleaning operation on the drum cartridge located at the uppermost position in the predetermined direction higher than the frequency of performing the cleaning operation on the other drum cartridges.

9. The image forming apparatus according to any one of claims 1 to 8, wherein the controller performs the cleaning operation, thereby performing the toner discharge operation from the cleaning roller to the photoreceptor drum and the paper dust collection operation from the photoreceptor drum to the cleaning roller.

10. The main casing and A toner cartridge having a developing roller, and further comprising The image forming apparatus according to any one of claims 1 to 9, wherein the drum cartridge is used together with the toner cartridge and is mounted in the main body housing together with the toner cartridge.

11. The image forming apparatus according to claim 10, wherein the drum cartridge and the toner cartridge are detachably attached to and removed from the main body housing independently of each other.

12. The image forming apparatus according to any one of claims 1 to 11, wherein the cleaning roller cleans the surface by contacting the surface.

13. The image forming apparatus according to claim 12, wherein the cleaning roller cleans the surface and recovers any deposits on the surface.

14. A control method for an image forming apparatus comprising a photoreceptor drum, a drum cartridge having a cleaning roller that contacts the surface of the photoreceptor drum and memory, and a humidity sensor for measuring humidity, A reading step of reading drum deterioration information representing the deterioration state of the photoreceptor drum or roller deterioration information representing the deterioration state of the cleaning roller from the memory, The system includes a determination step of determining the frequency of performing a cleaning operation of the photoreceptor drum by the cleaning roller based on the read-out drum deterioration information or roller deterioration information, In the aforementioned decision-making process, A first life value representing the remaining life of the photoreceptor drum obtained from the drum degradation information or A second life value, which represents the remaining life of the cleaning roller obtained from the roller deterioration information, When it is determined that the humidity is above a threshold, and further determined that the detection result of the humidity sensor is above a first humidity threshold, the frequency of performing the cleaning operation is increased. If it is not determined that the first life value or the second life value is equal to or greater than the threshold, the frequency of performing the cleaning operation is increased when it is determined that the detection result of the humidity sensor is less than the second humidity threshold. A control method for an image forming apparatus.

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