Image forming apparatus with a toner supply device

文档序号：1323632 发布日期：2020-07-14 浏览：9次中文

阅读说明：本技术 图像形成装置 (Image forming apparatus with a toner supply device ) 是由望月正贵阿部克市于 2020-01-08 设计创作，主要内容包括：本发明公开了图像形成装置。图像形成装置具有分别具有显影剂承载构件的不同旋转圆周速度比的第一模式和第二模式,该图像形成装置存储与第一模式对应的显影装置的第一寿命阈值和与第二模式对应的显影装置的第二寿命阈值；当显影剂承载构件在第一模式和第二模式下操作时,基于驱动量信息更新显影装置的寿命确定值；基于第一寿命阈值和寿命确定值执行与第一模式下的寿命相关的第一确定；基于第二寿命阈值和寿命确定值执行与第二模式下的寿命相关的第二确定；以及基于确定结果进行通知。(The invention discloses an image forming apparatus. An image forming apparatus having a first mode and a second mode respectively having different rotational circumferential speed ratios of the developer carrying member, the image forming apparatus storing a first life threshold of a developing device corresponding to the first mode and a second life threshold of the developing device corresponding to the second mode; updating a life determination value of the developing device based on the driving amount information when the developer carrying member operates in the first mode and the second mode; performing a first determination related to lifetime in the first mode based on the first lifetime threshold and the lifetime determination value; performing a second determination related to lifetime in the second mode based on the second lifetime threshold and the lifetime determination value; and notifying based on the determination result.)

1. An image forming apparatus, comprising:

a rotatable image bearing member; and

a developing device including a developer carrying member that supplies a developer to the image bearing member and develops an electrostatic latent image on the image bearing member,

the image forming apparatus has a first mode in which the developer bearing member rotates at a first peripheral speed ratio with respect to the image bearing member, and a second mode in which the developer bearing member rotates at a second peripheral speed ratio with respect to the image bearing member that is greater than the first peripheral speed ratio, wherein the image forming apparatus includes:

a storage unit that stores a first life threshold of the developing device corresponding to the first mode and a second life threshold of the developing device corresponding to the second mode;

a controller that adds the driving amount information of the developer carrying member to the lifetime determination value of the developing device or subtracts the driving amount information of the developer carrying member from the initial value in increments, based on first driving amount information when the developer carrying member operates in the first mode and second driving amount information when the developer carrying member operates in the second mode, to update the lifetime determination value; and

a notification unit for notifying, among other things,

the controller performs the following processing:

performing a first determination related to life in the first mode based on (i) the first life threshold and the life determination value or (ii) the life determination value and a third life threshold calculated using one of the second life threshold and the reference life threshold; and

performing a second determination related to life in the second mode based on (i) the second life threshold and the life determination value or (ii) the life determination value and a fourth life threshold calculated using one of the first life threshold and the reference life threshold, and

the notification unit performs notification based on a determination result of the controller.

2. The image forming apparatus according to claim 1, wherein

Controller

Comparing the life determination value to a first life threshold and determining whether the life determination value exceeds or falls below the first life threshold, an

The life determination value is compared to a second life threshold and a determination is made as to whether the life determination value exceeds or falls below the second life threshold.

3. The image forming apparatus according to claim 2, further comprising

A remaining amount acquiring section acquiring an amount of the developer stored in the developer container to be supplied to the developer carrying member, wherein

The controller determines that the developing device has reached the life of the developing device when the remaining amount of the developer is small, even when the life determination value does not exceed the first life threshold or the second life threshold.

4. An image forming apparatus, comprising:

a rotatable image bearing member; and

a developing device including a developer carrying member that supplies a developer to the image bearing member and develops an electrostatic latent image on the image bearing member,

a storage unit that stores any one of a first life threshold value of the developing device corresponding to the first mode, a second life threshold value of the developing device corresponding to the second mode, and a reference life threshold value;

a controller that calculates a lifetime determination value based on first driving amount information when the developer carrying member operates in the first mode and second driving amount information when the developer carrying member operates in the second mode; and

a notification unit for notifying, among other things,

the controller performs the following processing:

the notification unit performs notification based on a determination result of the controller.

5. The image forming apparatus according to claim 4, wherein

Controller

Comparing the life determination value to the first or third life threshold and determining whether the life determination value exceeds or falls below the first or third life threshold, an

The life determination value is compared to the second or fourth life threshold and a determination is made as to whether the life determination value exceeds or falls below the second or fourth life threshold.

6. The image forming apparatus according to claim 5, further comprising

A remaining amount acquiring section acquiring an amount of the developer stored in the developer container to be supplied to the developer carrying member, wherein

7. The image forming apparatus according to any one of claims 1 to 6, wherein

After the controller makes a notification based on the determination result of the second determination, the controller allows the continued execution of the first mode.

8. The image forming apparatus according to any one of claims 1 to 6, wherein

The storage unit stores a first correction coefficient, an

The controller updates the lifetime determination value by reading the first correction coefficient stored in the storage unit and using the read first correction coefficient with respect to the first driving amount information and/or the second driving amount information, by making a magnitude of the driving amount information to be added or subtracted successively based on the second driving amount information larger than a magnitude of the driving amount information to be added or subtracted successively based on the first driving amount information with respect to the same driving amount of the developer carrying member.

9. The image forming apparatus according to claim 8, wherein

The first correction coefficient includes at least one of a second correction coefficient according to information relating to a usage amount of the developing device and a third correction coefficient according to a rotational peripheral speed ratio between the image bearing member and the developer bearing member.

10. The image forming apparatus according to claim 8, wherein

The storage unit stores a fourth correction coefficient according to a remaining life of the developer bearing member, an

The controller uses the first correction coefficient, which has been corrected with the fourth correction coefficient, with respect to the first driving amount information and/or the second driving amount information.

11. The image forming apparatus according to any one of claims 1 to 6, wherein

The second life threshold is divided into a plurality of ranges according to the remaining life of the developer carrying member, an

The controller performs a second determination regarding the lifetime in the second mode based on the lifetime determination value and a second lifetime threshold value that has been divided by the plurality of ranges.

12. The image forming apparatus according to any one of claims 1 to 6, wherein

The storage unit stores a fifth correction coefficient according to a remaining life of the developer bearing member, an

The controller performs the second determination based on the life determination value and the second life threshold value that has been corrected by the fifth correction coefficient.

13. An image forming apparatus, comprising:

a rotatable image bearing member; and

a developing device including a developer carrying member that supplies a developer to the image bearing member and develops an electrostatic latent image on the image bearing member,

a storage unit storing a life threshold of the developing device;

a controller that calculates a first life determination value corresponding to the first mode and a second life determination value corresponding to the second mode based on first driving amount information when the developer carrying member operates in the first mode and second driving amount information when the developer carrying member operates in the second mode; and

a notification unit for notifying, among other things,

the controller causes:

the notification unit performs a first notification relating to a lifetime of the developing device in the first mode based on a comparison between the lifetime threshold value and the first lifetime determination value; and

the notification unit performs a second notification relating to the lifetime of the developing device in the second mode based on a comparison between the lifetime threshold value and the second lifetime determination value.

Technical Field

The present invention relates to a technique for determining the life of a developing device provided in an image forming apparatus such as a copying machine, a printer, a facsimile machine, or the like using an electrophotographic system, an electrostatic recording system, or the like.

Background

In an image forming apparatus such as a printer using an electrophotographic image forming system (electrophotographic process), an electrophotographic photosensitive member (hereinafter referred to as "photosensitive member") as an image bearing member is uniformly charged and the charged photosensitive member is selectively exposed to form an electrostatic image on the photosensitive member. The electrostatic image formed on the photosensitive member is developed as a toner image with toner as a developer. Subsequently, image recording is performed by transferring the toner image formed on the photosensitive member onto a recording material such as a recording paper sheet or a plastic sheet, and further applying heat and pressure to the toner image having been transferred onto the recording material to fix the toner image to the recording material.

Such image forming apparatuses generally require replenishment of developer and maintenance of various process components (means). In order to facilitate such replenishing operation of the developer and maintenance of various process components, a process cartridge, which is made by disposing a photosensitive member, a charging unit, a developing unit, a cleaning unit, and the like together inside a frame body and is attachable to and detachable from an image forming apparatus main body, is put into practical use. According to the process cartridge system, an image forming apparatus having excellent usability can be provided.

With such a process cartridge, as the number of times image formation is performed increases, toner that is repeatedly recovered without being developed on a photosensitive drum as an example of a photosensitive member is generated. Such a toner may cause deterioration because repeated formation of a toner image causes the added external additive to be released from or embedded in the resin particles constituting the basis of the toner. In this case, since the toner cannot obtain a desired amount of charge, so-called fogging or the like in which the toner adheres to a white portion of an image may occur. In view of this, japanese patent No.4743273 proposes to calculate the degree of deterioration of toner in an image forming apparatus, and determine that the developing apparatus has reached the end of its life by integrating the degree of deterioration. Further, japanese patent application laid-open No. 2016-.

In recent years, one of various market demands is to increase image density (density) and expand hue (tint) to enable an image with enhanced color to be obtained. For this reason, the following techniques are known. There is a technique which includes a mode for changing a peripheral speed ratio between the photosensitive drum and the developing roller as a means for achieving a high image density and increasing a color tone, in addition to a mode for obtaining a general image density, and which increases a toner supply amount to the photosensitive drum to increase a toner amount on a recording medium.

Studies performed by the present inventors have shown that performing printing by increasing the circumferential speed ratio between the photosensitive drum and the developing roller using such a technique affects the deterioration of the developing roller. When the developing roller is prematurely deteriorated, the volume resistance value increases, and since the charge of the toner on the developing roller is less likely to be discharged to the developing roller, the toner starts to store the charge. Therefore, for example, the electric charge held by the toner on the developing roller becomes excessive, and the control of the control member becomes insufficient. For this reason, a so-called control failure may occur at an early timing, and an increase in the amount of toner on the developing roller due to the control failure may cause banding to occur due to slippage of the developing roller and the photosensitive drum. In other words, it is desirable to notify the user of the life of the developing device at an appropriate timing.

Disclosure of Invention

In order to achieve the above object, an image forming apparatus of the present invention includes:

a rotatable image bearing member; and

a developing device including a developer carrying member that supplies a developer to the image bearing member and develops an electrostatic latent image on the image bearing member,

a storage unit that stores a first life threshold of the developing device corresponding to the first mode and a second life threshold of the developing device corresponding to the second mode;

a controller that adds or subtracts the driving amount information of the developer carrying member to or from a progressive order of a lifetime determination value of the developing device based on first driving amount information when the developer carrying member operates in the first mode and second driving amount information when the developer carrying member operates in the second mode to update the lifetime determination value; and

a notification unit for notifying, among other things,

the controller performs the following processing:

the notification unit performs notification based on a determination result of the controller.

In order to achieve the above object, an image forming apparatus of the present invention includes:

a rotatable image bearing member; and

a developing device including a developer carrying member that supplies a developer to the image bearing member and develops an electrostatic latent image on the image bearing member,

a notification unit for notifying, among other things,

the controller performs the following processing:

the notification unit performs notification based on a determination result of the controller.

In order to achieve the above object, an image forming apparatus of the present invention includes:

a rotatable image bearing member; and

a developing device including a developer carrying member that supplies a developer to the image bearing member and develops an electrostatic latent image on the image bearing member,

a storage unit storing a life threshold of the developing device;

a notification unit for notifying, among other things,

the controller causes:

Further features of the invention will become apparent from the following description of exemplary embodiments (with reference to the attached drawings).

Drawings

FIG. 1 is a schematic view of an image forming apparatus;

FIG. 2 is a schematic view of a drum cartridge;

fig. 3 is a schematic view of the developing cartridge;

FIG. 4 is a hardware block diagram of the image forming apparatus;

fig. 5A to 5C are explanatory diagrams of the relationship between the traveling distance of the developing roller, the control failure, and the belt;

fig. 6A and 6B are sequence charts of lifetime determination of the developing cartridge;

fig. 7A and 7B are sequence diagrams of another life determination of the developing cartridge;

fig. 8A and 8B are sequence diagrams of another life determination of the developing cartridge;

fig. 9A and 9B are sequence diagrams of another life determination of the developing cartridge;

fig. 10A to 10C are graphs of the relationship between the remaining toner amount and the remaining life of the developing roller;

FIG. 11 is an explanatory diagram of a developing roller life line;

fig. 12 is a diagram showing the notification timing of the lifetime of the developing cartridge; and

fig. 13 is a diagram showing the occurrence of banding in the high density mode.

Detailed Description

Hereinafter, exemplary embodiments for performing the present invention will be described in detail with reference to the accompanying drawings. The size, material, shape, and relative arrangement of the components described in the embodiments may be appropriately changed depending on the configuration of the apparatus to which the present invention is applied and various conditions. That is, the scope of the present invention is not limited to the following examples.

First embodiment

The overall configuration of an embodiment of an electrophotographic image forming apparatus (image forming apparatus) will be described. Fig. 1 is a sectional view of an image forming apparatus 100 according to the present embodiment. The image forming apparatus 100 according to the present embodiment is a full-color laser beam printer employing an in-line (in-line) system and an intermediate transfer system. The image forming apparatus 100 is capable of forming a full-color image on a recording material (e.g., recording paper, plastic sheet, and cloth) according to image information. Image information is input to the image forming apparatus main body from an image reading apparatus connected to the image forming apparatus main body or a host device such as a personal computer connected to the image forming apparatus main body so as to be able to communicate. The image forming apparatus 100 has SY, SM, SC, and SK as a plurality of image forming portions for forming images of each color of yellow (Y), magenta (M), cyan (C), and black (K), respectively. In the present embodiment, the image forming portions SY, SM, SC, and SK are arranged in a single line in a direction intersecting the vertical direction.

Although a detailed description will be given later, in the image forming apparatus 100 according to the present embodiment, the photosensitive drum 1, the charging roller 2, the cleaning blade 6, and the drum cartridge frame body 11 shown in fig. 2 are integrally configured as a drum cartridge 210 for the purpose of simplifying maintenance and the like. Further, the developing roller 4, the toner supplying roller 5, the toner amount control member 8, and the developer container 22 constituting the developing chamber 20a and the developer storage chamber 20b shown in fig. 3 are integrally configured in a similar manner as a developing cartridge 200 as a developing device.

The previously described image forming portion is constituted by the drum cartridges 210(210Y, 210M, 210C, and 210K) and the developing cartridges 200(200Y, 200M, 200C, and 200K). The drum cartridge 210 and the developing cartridge 200 are configured to be attachable to and detachable from the image forming apparatus 100 via a mounting member (such as a mounting guide, a positioning member, or the like) provided on the image forming apparatus main body. In the present embodiment, all the drum cartridges 210 and the developing cartridges 200 for the respective colors have the same shape, and the toners of the respective colors of yellow (Y), magenta (M), cyan (C), and black (K) are stored in the developing cartridges 200 for the respective colors. Although a configuration in which the drum cartridge 210 and the developing cartridge 200 are independently attachable and detachable will be described in the present embodiment, alternatively, a configuration may be adopted in which the drum cartridge 210 and the developing cartridge 200 are integrated and are attachable to and detachable from the image forming apparatus main body as a single component.

The photosensitive drum 1 is rotationally driven by a driving member (driving source) (not shown). A scanner unit (exposure device) 30 is arranged around the photosensitive drum 1. The scanner unit 30 is an exposure unit that irradiates a laser beam based on image information and forms an electrostatic image (electrostatic latent image) on the photosensitive drum 1. For each scanning line, writing by laser exposure is performed in the main scanning direction (direction perpendicular to the conveying direction of the recording material 12) in accordance with a position signal called BD inside the polygon scanner. Meanwhile, in the sub-scanning direction (the conveying direction of the recording material 12), writing of laser exposure is performed after a delay of a prescribed time in accordance with a TOP signal originating from a switch (not shown) inside the conveying path of the recording material 12. Therefore, in the four process stations Y, M, C and K, laser exposure can always be performed with respect to the same position on the photosensitive drum 1.

An intermediate transfer belt 31 as an intermediate transfer member for transferring the toner images on the photosensitive drums 1 to the recording material 12 is disposed opposite to the four photosensitive drums 1. The intermediate transfer belt 31, which is an intermediate transfer member formed of an endless belt, is in contact with all the photosensitive drums 1, and is circularly moved (rotated) in the direction of the illustrated arrow B (counterclockwise). Four primary transfer rollers 32 as a primary transfer unit are arranged in parallel with each other on the inner peripheral surface side of the intermediate transfer belt 31 so as to be opposed to each photosensitive drum 1. Further, a bias having a polarity opposite to the normal charging polarity of the toner is applied to the primary transfer roller 32 from a primary transfer bias power source (high-voltage power source) as a primary transfer bias applying unit (not shown). Thus, the toner image on the photosensitive drum 1 is transferred (primary transfer) onto the intermediate transfer belt 31.

Further, a secondary transfer roller 33 as a secondary transfer unit is disposed on the outer peripheral surface side of the intermediate transfer belt 31. Further, a bias having a polarity opposite to the normal charging polarity of the toner is applied to the secondary transfer roller 33 from a secondary transfer bias power source (high-voltage power source) as a secondary transfer bias applying unit (not shown). Thus, the toner image on the intermediate transfer belt 31 is transferred (secondary transfer) onto the recording material 12. For example, when a full-color image is formed, the above-described processes are sequentially performed by the image forming portions SY, SM, SC, and SK, and the toner images of the respective colors are primarily transferred onto the intermediate transfer belt 31 by being sequentially superimposed on one another. Subsequently, the recording material 12 is conveyed to the secondary transfer portion in synchronization with the movement of the intermediate transfer belt 31. Further, the four color toner images on the intermediate transfer belt 31 are collectively secondary-transferred onto the recording material 12 due to the action of the secondary transfer roller 33 contacting the intermediate transfer belt 31 via the recording material 12.

The recording material 12 to which the toner image has been transferred is conveyed to a fixing device 34 as a fixing unit. The fixing device 34 applies heat and pressure to the recording material 12 to fix the toner image onto the recording material 12.

Drum box

The configuration of the drum cartridge 210 to be mounted to the image forming apparatus 100 according to the present embodiment will be described. Fig. 2 is a sectional (front sectional) view of the drum cartridge 210 according to the present embodiment as viewed along the longitudinal direction (rotation axis direction) of the photosensitive drum 1.

The photosensitive drum 1 is rotatably attached to the drum cartridge 210 via a bearing (not shown). By receiving the driving force of the drive motor as the photosensitive drum drive unit (drive source M210), the photosensitive drum 1 is rotationally driven in the illustrated arrow a direction according to the image forming operation.

As the photosensitive drum 1, an organic photosensitive member in which an outer circumferential surface of an aluminum cylinder having a diameter of 30mm is coated with an undercoat layer as a functional film (membranes), a high resistance layer, a carrier layer, and a carrier transfer layer in this order was used. Since the carrier transfer layer is scraped and abraded by the image forming operation, it is necessary to form a film thickness corresponding to the life of the drum cartridge 210. To accommodate recent market demands, the present embodiment employs a film thickness of 25 μm to achieve an extended lifetime.

Further, the charging roller 2 and the cleaning blade 6 formed of an elastic body are arranged in the drum cartridge 210 so as to be in contact with the outer peripheral surface of the photosensitive drum 1. Further, a drum cartridge frame body 11 is provided, the drum cartridge frame body 11 having a storage space for storing the toner on the photosensitive drum 1 which has been removed by the cleaning blade 6. A bias sufficient to cause any charge to be carried on the photosensitive drum 1 is applied to the charging roller 2 from a charging bias power supply (high-voltage power supply) as a charging bias applying unit (not shown). In this embodiment, the applied bias is set so that the potential (charging potential: Vd) on the photosensitive drum 1 is-500V. Based on the image information, a laser beam 35 is irradiated from the scanner unit 30, and an electrostatic image (electrostatic latent image) is formed on the photosensitive drum 1. As a result of irradiation of the laser beam 35, in the irradiated portion, the charge on the surface of the photosensitive drum 1 is eliminated by the carriers from the carrier generation layer, and the potential drops. Thus, an electrostatic latent image is formed in which the portion irradiated with the laser beam 35 has a prescribed bright portion potential (Vl), and the portion not irradiated has a prescribed dark portion potential (Vd).

Further, the drum cartridge 210 is provided with a nonvolatile memory (hereinafter referred to as an O memory m1) as a storage unit. The O memory m1 stores information such as the number of rotations, serial number, and the like of the photosensitive drum 1, and based on the information stored in the O memory m1, the amount of use of the drum cartridge can be evaluated. The O memory m1 is configured to be capable of communicating (writing and reading information) with the control portion 300 of the image forming apparatus 100 illustrated in fig. 1 in a non-contact manner or by contact via electrical contacts (not shown).

Developing box

Next, the configuration of the developing cartridge 200 to be mounted to the image forming apparatus 100 according to the present embodiment will be described. Fig. 3 is a sectional (front sectional) view of the developing cartridge 200 according to the present invention as viewed along the longitudinal direction (rotational axis direction) of the developing roller 4.

The developing cartridge 200 includes a developing chamber 20a and a developer storage chamber 20b, a developing roller 4, a toner supplying roller 5, and a developer container 22 constituting the developing chamber 20a and the developer storage chamber 20 b. The developer storage chamber 20b is disposed below the developing chamber 20 a. The toner 9 as the developer is stored in the developer storage chamber 20 b. In the present embodiment, a negative polarity is used as the normal charging polarity of the toner 9, and hereinafter, a case of using a negatively charged toner will be described. However, the present invention is not limited to negatively charged toners.

Further, the developer storage chamber 20b is provided with a developer conveying member 21 for conveying the toner 9 to the developing chamber 20a, and the developer conveying member 21 conveys the toner 9 to the developing chamber 20a by rotating in the direction of the illustrated arrow G. The developer conveying member 21 is constituted by a sheet-like member having elasticity extending in the longitudinal direction of the cartridge.

The developing chamber 20a is provided with a developing roller 4 as a developer bearing member, the developing roller 4 being in contact with the corresponding photosensitive drum 1 and rotated in the direction of an arrow D shown by receiving a driving force from a driving motor as a development driving unit (driving source M200). In the present embodiment, the developing roller 4 and the photosensitive drum 1 are respectively rotated so that the surfaces thereof move in the same direction at the opposing portions (contact portions). Further, the developing roller 4 is configured such that a conductive elastic rubber layer having a prescribed volume resistance is provided around the metal core. Further, a bias voltage sufficient to develop and visualize the electrostatic latent image on the photosensitive drum 1 as a toner image is applied from a developing bias power source (high-voltage power source) as a developing bias applying unit (not shown).

Further, a toner supply roller (hereinafter simply referred to as "supply roller") 5 that supplies the toner conveyed from the developer storage chamber 20b to the developing roller 4 and a toner amount control member (hereinafter simply referred to as "control member") 8 that controls the coating amount and supplies an electric charge to the toner on the developing roller 4 that has been supplied by the supply roller 5 are arranged inside the developing chamber 20 a.

Further, the developing cartridge 200 is provided with a nonvolatile memory (hereinafter referred to as DT memory m2) as a storage unit. The DT memory m2 stores the total driving amount of the developing roller 4, the remaining toner amount, and the like, and based on the information stored in the DT memory m2, the usage amount of the developing cartridge can be evaluated. The remaining toner amount is an amount of toner remaining in the toner stored inside the developing cartridge 200. The DT memory m2 is configured to be able to communicate (write and read information) with the control portion 300 of the image forming apparatus 100 in a non-contact manner or by contact via electrical contacts (not shown).

Image forming mode

The image forming apparatus 100 according to the present embodiment has two image forming modes. The first mode is an image forming mode for obtaining a normal image density (hereinafter referred to as a normal mode). The second mode is an image forming mode for obtaining a high density or increasing a tone selection range by increasing a rotational peripheral speed ratio between the photosensitive drum 1 as an image bearing member and the developing roller 4 as a developer bearing member while lowering a dark portion potential on the image bearing member (hereinafter referred to as a high density mode). As described above, the rotational peripheral speed ratio in the second mode (second peripheral speed ratio) is larger than the rotational peripheral speed ratio in the first mode (first peripheral speed ratio).

Specific differences in control between the normal mode and the high concentration mode according to the present embodiment are shown in table 1 below.

[ Table 1]

In table 1, the dark portion potential Vd indicates a potential on the surface of the photosensitive drum 1 after the surface of the photosensitive drum 1 is charged by the charging roller 2. Further, the bright portion potential Vl represents a potential on the surface of the photosensitive drum 1 after irradiation of the laser beam 35. The development potential Vdc represents a potential applied to the development roller 4 by the development bias power source.

The rotational peripheral speed ratio according to the present embodiment is the rotational peripheral speed ratio of the developing roller 4 when the rotational peripheral speed of the photosensitive drum 1 is 1. Specifically, in the normal mode, the rotational peripheral speed of the photosensitive drum 1 is set to 200 mm/sec, and the rotational peripheral speed of the developing roller 4 is set to 280 mm/sec. Meanwhile, in the high density mode, the rotational peripheral speed of the photosensitive drum 1 is set to 100 mm/sec, and the rotational peripheral speed of the developing roller 4 is set to 250 mm/sec. Assuming that the amount of toner on the recording material 12 has been increased, the rotational peripheral speed of the photosensitive drum 1 is slowed in the high density mode in order to ensure good fixability. Although the amount of heat applied to the recording material 12 in the fixing device 34 can be increased, since this also increases power consumption, in the present embodiment, the rotational peripheral speed of the photosensitive drum 1 is reduced.

As shown in table 1, in the high density mode, the difference between the development potential Vdc and the bright portion potential Vl (hereinafter referred to as development contrast) is set larger than in the normal mode. Therefore, in the high density mode, a large amount of toner among the toners coating the developing roller 4 is developed onto the photosensitive drum 1 as compared with the normal mode. Further, by setting a large rotational peripheral speed ratio between the photosensitive drum 1 and the developing roller 4, the amount of toner supplied from the developing roller 4 per unit area of the photosensitive drum 1 increases. Due to these two effects, the amount of toner on the recording material 12 can be increased, and an image having high density and high color gamut (color gamut) can now be printed.

Remaining toner amount detection method

The remaining toner amount detection method by the video counting system used in the present embodiment will now be described. Fig. 4 is a hardware block diagram of the image forming apparatus according to the present embodiment. The control part 300 of the image forming apparatus 100 is provided with a CPU501, and the CPU501 executes various calculation processes and also functions as a correction information acquisition part that acquires correction amount information such as a correction distance of the developing roller 4 and a remaining amount acquisition part that acquires information on the amount of remaining toner, which will be described later. Further, an image forming apparatus main body side memory 502 is provided which stores information necessary for controlling the motor driving portion 511 and the high voltage power supply 512. Further, communication with the control section 300 is performed by inputting and outputting information stored in the O memory m1 of the drum cartridge 210 and the DT memory m2 of the developing cartridge 200 to and from the CPU501 from the input/output I/F503 via the memory communication section 500. Also, a video count measuring section 305 that measures a video signal output according to an image forming operation is connected to the control section 300.

The principle of remaining toner amount detection using video counting will now be described. A separate control device (not shown) is disposed on the upstream side of the control section 300, a laser driving signal (video signal) from the control device is branched, and the video signal is sampled during a period in which an electrostatic latent image is formed on the photosensitive drum. The sampled video signal is input to a hardware counter inside the control section 300, and the number of ON among ON/OFF of the video signal is counted and the value thereof is read by the CPU 501. The read value indicates consumption of toner, and a value obtained by subtracting the count value from a prescribed initial value in increments is information indicating the amount of remaining toner. Further, by dividing the number of ONs of the video signal by the count of ONs measured when it is assumed that a full black image is printed in an area ON the recording material where an image is to be printed, a ratio indicating how long the laser beam has been emitted so as to form an electrostatic latent image can be obtained. An electrostatic latent image is formed in a portion irradiated with the laser beam, and since toner adheres to the portion, the remaining toner amount can be calculated based on the light emission ratio of the laser beam. Although the count of the video count measuring section 305 specifically corresponds to the count of the ON video signal during which the laser beam is irradiated, the sampling period thereof does not have to be synchronized with the video clock of the video signal. The video count measurement section 305 may count the pixel information asynchronously with the video clock if sampling is to be performed at a shorter period than the video clock. Further, the CPU501 provided in the control section 300 calculates the remaining amount of the toner 9 inside the developing cartridge 200 from the measured video count value.

The video count measurement section 305 measures pixel information (video count value VCn) of the output image. In the present embodiment, a sheet of output recording material 12 is employed as a video count value VCn. The CPU501 calculates the remaining toner amount according to the following procedure. First, the video count value VCn measured by the video count measuring portion 305 is added to the accumulated video count value VCr since the development cartridge 200 was started to be used, which is stored in the DT memory m2 of the development cartridge 200, to calculate the total video count value VCt.

VCt＝VCr+VCn

Next, the CPU501 calculates the remaining toner amount TP inside the developing cartridge 200 from the video count threshold VCth and the total video count value VCt stored in the DT memory m 2.

TP[％]＝(1-VCt/VCth)×100

Subsequently, the CPU501 writes the total video count value VCt as an accumulated video count value VCr into the DT memory m 2.

At this time, the remaining toner amount TP of 100% represents a state in which the toner 9 inside the developing cartridge 200 is full and the developing cartridge 200 is brand-new. Further, the remaining toner amount TP of 0% represents a state in which the remaining amount of the toner 9 inside the developing cartridge 200 is almost zero and it has been time to replace the developing cartridge 200.

In the present embodiment, the video count threshold VCth at the time when the remaining toner amount TP is 0% is set based on the remaining amount of toner 9, which prevents toner supply from the supply roller 5 to the developing roller 4 from being insufficient even when a high-print image such as a solid image is printed. Thus, for example, TP may be set to 5% of the actual remaining toner amount.

Developing roller service life calculation method

Next, a method of calculating the lifetime of the developing roller 4 will be described. The life of the developing roller 4 is determined according to the travel distance Wu of the developing roller 4. Although a description will be given below using the travel distance Wu as an example of the driving amount information indicating how much the developing roller 4 has been driven, various parameters may be used as the driving amount information as long as the parameters indicate how much the developing roller 4 has been driven. For example, the total driving time of the developing cartridge 200 may be used, or the total number of revolutions of the developing roller 4 may be used. Alternatively, the number of prints formed by using the developing cartridge 200 may be used.

The image forming apparatus 100 is provided with a developing roller travel distance measuring section 302 that measures the travel distance Wu of the developing roller 4, and the CPU501 corrects the measured travel distance Wu of the developing roller 4 using the developing roller travel distance correction coefficient k.

The developing roller traveling distance measuring portion 302 calculates the traveling distance Wu from the driving time Td of the developing cartridge 200, the process speed Ps of the image forming apparatus 100, and the peripheral speed ratio Sr of the developing roller 4 with respect to the photosensitive drum 1.

Wu＝Td×Ps×Sr

In this case, the travel distance Wu indicates how far a given point on the surface of the developing roller 4 has advanced due to the rotation of the developing roller 4. The process speed Ps of the image forming apparatus 100 is the rotation speed of the photosensitive drum 1.

The CPU501 reads a developing roller travel distance correction coefficient k, which is a first correction coefficient stored in the DT memory m 2. The CPU501 may read the developing roller travel distance correction coefficient k (second correction coefficient) from the information relating to the usage amount of the developing cartridge 200. The information related to the usage amount of the developing cartridge 200 may include information such as the cumulative number of rotations of the developing roller 4, the cumulative rotational time of the developing roller 4, the usage amount of toner, and the remaining toner amount TP. The used amount of toner is the amount of toner 9 used among the toner 9 stored inside the developing cartridge 200. The remaining toner amount TP is an amount of the toner 9 remaining among the toners 9 stored inside the developing cartridge 200. The usage amount of toner may be obtained by subtracting the remaining toner amount TP from the amount of toner inside the developing cartridge 200 before the start of use. The remaining toner amount TP may be obtained by subtracting the amount of toner used from the amount of toner inside the developing cartridge 200 before the start of use. The information related to the usage amount of the developing cartridge 200 may be a value obtained by dividing the cumulative number of revolutions or the cumulative rotational time of the developing roller 4 by a first prescribed value related to the developing roller 4. The first prescribed value related to the developing roller 4 is the number of revolutions or the rotation time of the developing roller 4 and is a value set based on the lifetime of the developing roller 4. The information related to the usage amount of the developing cartridge 200 may be a value obtained by dividing the usage amount of the toner by the amount of the toner inside the developing cartridge 200 before the start of use. The information related to the usage amount of the developing cartridge 200 may be a value obtained by dividing the remaining toner amount TP by the amount of toner inside the developing cartridge 200 before the start of use. Based on the information retained in the DT memory m2, the CPU501 can acquire information relating to the usage amount of the developing cartridge 200.

The CPU501 may read the developing roller travel distance correction coefficient k (third correction coefficient) according to the image forming mode. Specifically, the CPU501 reads the developing roller travel distance correction coefficient k according to the rotational peripheral speed ratio between the photosensitive drum 1 and the developing roller 4. For example, the developing roller travel distance correction coefficient k read by the CPU501 may be set so that k is 1 in the normal mode and 1.5 in the high density mode. Further, the CPU501 may read the developing roller travel distance correction coefficient k calculated by multiplying the correction coefficient k1 according to the information relating to the usage amount of the developing cartridge 200 by the correction coefficient k2 according to the image forming mode. Correction coefficients k1 and k2 are stored in DT memory m 2.

Further, as a corrected distance acquisition unit, the CPU501 calculates a corrected developing roller travel distance Hu by multiplying a prescribed travel distance Wu by a developing roller travel distance correction coefficient k.

Hu＝Wu×k

Next, the CPU501 adds the corrected developing roller travel distance Hu to the post-progressive addition development roller travel distance HT stored in the DT memory m2 in increments since the start of use of the developing cartridge 200_n-1. Therefore, the CPU501 calculates the corrected distance to the total or, in other words, the latest after-addition developing roller travel distance HT_nCorresponding total corrected developer roller travel distance HT_n(n＝1，2，...，n，HT₀＝0)。

HT_n＝HT_n-1+Hu

Subsequently, according to the developing roller travel distance threshold Wth in the normal mode stored in the DT memory m2₁And the latest after-addition developing roller travel distance HT_nThe CPU501 calculates the developing roller remaining life DP1 in the normal mode using the following calculation formula.

DP1[％]＝(1-HT_n/Wth₁)×100

Further, according to the developing roller travel distance threshold Wth in the high density mode stored in the DT memory m2₂And the latest after-addition developing roller travel distance HT_nThe CPU501 calculates the developing roller remaining life DP2 in the high density mode using the following calculation formula.

DP2[％]＝(1-HT_n/Wth₂)×100

Developing roller travel distance threshold Wth in normal mode₁(hereinafter referred to as a travel distance threshold Wth)₁) Is an example of the first life threshold value relating to the life of the developing roller 4. Developing roller travel distance threshold Wth in high density mode₂(hereinafter referred to as a travel distance threshold Wth)₂) Is an example of the second life threshold value relating to the life of the developing roller 4.

Subsequently, the latest after-addition developing roller travel distance HT_n(life determination value) is written in the DT memory m2 and updated to the post-increment development roller travel distance HT at the next life determination_n-1。

It should be noted that the case where the remaining life DP1 or DP2 of the developing roller is 100% represents a completely new developing cartridge 200. Further, the case where the remaining life DP1 or DP2 of the developing roller is equal to or less than 0% indicates that the replacement timing of the developing cartridge 200 is reached.

In the present embodiment, the travel distance threshold Wth in the normal mode₁Is set based on the developing roller traveling distance at which the control member 8 no longer sufficiently controls the toner application amount on the developing roller 4 and fogging of toner to a white portion occurs due to a control failure in the normal mode. Travel distance threshold value Wth in high density mode₂Is set based on a developing roller traveling distance at which slippage of the photosensitive drum 1 and the developing roller 4 causes image density unevenness due to banding when the circumferential speed ratio between the photosensitive drum 1 and the developing roller 4 is set high in a prescribed state. The prescribed state is a state in which: although a control failure significant enough to cause fogging of toner to a white portion has not occurred, it is at the developing roller 4A slight control failure still occurs in the latter half of the life.

The relationship between the travel distance of the developing roller, the control failure, and the belt will now be described. The surfaces of the supply roller 5, the control member 8, and the photosensitive drum 1 are in contact with the developing roller 4, and a prescribed potential difference is generated between the developing roller 4 and the surfaces of the supply roller 5, the control member 8, and the photosensitive drum 1. At this time, a current flows to the developing roller 4, and the resistance value of the developing roller 4 increases (energization deterioration). When the resistance value of the developing roller 4 rises, the electric charge held by the toner 9 on the developing roller 4 is less easily discharged and the electric charge amount of the toner 9 increases. When the adhesion of the toner 9 to the developing roller 4 increases and the adhesion of the toner 9 exceeds the control force of the control member 8, the control member 8 is no longer able to sufficiently control the toner 9 and a control failure occurs.

The energization deterioration varies depending on the magnitude of the current flowing to the developing roller 4. Fig. 5A is a diagram illustrating a relationship between the rotational peripheral speed ratio between the developing roller 4 and the photosensitive drum 1 and the current value of the current flowing from the photosensitive drum 1 to the developing roller 4. When the rotational peripheral speed ratio between the photosensitive drum 1 and the developing roller 4 is changed, as shown in fig. 5A, the larger the rotational peripheral speed ratio, the larger the current value of the current flowing to the developing roller 4. In other words, the larger the rotational circumferential speed ratio, the more the energization deterioration progresses. When there are modes having different rotational peripheral speed ratios, it is necessary to correct them.

Referring to fig. 5B, a band that occurs when the amount of toner on the developing roller 4 increases due to a control failure in the latter half of the life of the developing roller 4 in the case where the high density mode is set will be described. Due to the control failure, when the amount of toner on the developing roller 4 increases at the position indicated by the arrow G1 in fig. 5B and at the same time the peripheral speed ratio between the developing roller 4 and the photosensitive drum 1 increases, the developing roller 4 can no longer follow the rotation of the photosensitive drum 1 at the nip portion 41. Therefore, when the developing roller 4 slips and speed unevenness occurs in the developing roller 4, unevenness in the amount of toner developed on the photosensitive drum 1 occurs at the position indicated by the arrow G2 in fig. 5B. Therefore, as shown in fig. 5C, image density unevenness (banding) occurs over the entire image printed on the recording material 12. When there are modes having different peripheral speed ratios between the photosensitive drum 1 and the developing roller 4, the timings at which the control failure occurs are different as in the case of the normal mode and the high density mode. Further, regarding the banding that occurs in the high density mode, since the larger the peripheral speed ratio, the earlier the timing of the banding occurs, it is necessary to set the developing roller travel distance threshold value for each image forming mode. Further, the degree of the process of the electrification deterioration varies depending on the characteristics of the developing roller 4. Since the specification of the developing roller 4 may be changed, it is preferable to store the developing roller traveling distance threshold in each image forming mode in the DT memory m2 mounted to the developing cartridge 200. However, the storage of the developing roller travel distance threshold in each image forming mode is not limited to this, but may instead be stored in a memory of the image forming apparatus main body.

Developing cartridge life determining sequence

Fig. 6A and 6B are sequence charts of lifetime determination of the developing cartridge 200 according to the first embodiment. By executing the processing shown in the flowcharts of fig. 6A and 6B as a controller (control unit) or determination unit based on the information in the DT memory m2 mounted to the developing cartridge 200, the CPU501 built in the control portion 300 determines the lifetime of the developing cartridge 200 and notifies the user of the determination result thereof.

The flowcharts shown in fig. 6A and 6B will be described. First, the image forming apparatus 100 receives print data based on a document created by an external computer via the external I/F504 (S501).

For example, the CPU501 selects the normal mode when "0" is set in the setting information included in the print data, and selects the high density mode when "1" is set in the setting information, and executes the subsequent processing (S502).

Next, the CPU501 starts an image forming operation of the image forming apparatus 100 including the developing cartridge 200 (S503). The image forming operation at this time includes all operations necessary for image formation, such as setting the charging potential of the charging roller 2, setting the developing potential of the developing roller 4, and rotationally driving the photosensitive drum 1 and the developing roller 4 having the prescribed rotational peripheral speed ratio described with reference to table 1. When the travel distance Wu is measured by the CPU501 at the start of driving of the developing roller 4, such measurement processing is also included in the image forming operation at this time. Further, the travel distance Wu measured when the normal mode is selected in S501 corresponds to the first driving amount information in the first mode, and the travel distance Wu measured when the high density mode is selected in S501 corresponds to the second driving amount information in the second mode.

Next, the CPU501 reads the developing roller travel distance correction coefficient k from the DT memory m2 (S504). As described previously, the CPU501 reads the developing roller travel distance correction coefficient k according to the information relating to the usage amount of the developing cartridge 200 and/or the developing roller travel distance correction coefficient k according to the image forming mode. When the CPU501 reads the developing roller travel distance correction coefficient k according to the image forming mode, for example, when the image forming mode is the high density mode, the CPU501 reads k 1.5, or when the image forming mode is the normal mode, the CPU501 reads k 1. When the correction coefficient of the selected image forming mode is 1, the CPU501 may skip the process of S102 because it is not necessary to perform correction.

Next, the CPU501 calculates a corrected developing roller travel distance Hu using the read developing roller travel distance correction coefficient k (S505). The timing at which the CPU501 calculates the corrected developing roller travel distance Hu may be after the end of printing or at predetermined intervals. In any case, the object of calculation is the distance of travel Wu that is not calculated.

Further, according to the corrected developing roller travel distance Hu and the previous post-addition developing roller travel distance HT stored in the DT memory m2_n-1The CPU501 calculates the latest after-addition developing roller travel distance HT_nAs the lifetime determination value (S506).

Next, the CPU501 determines whether the image forming mode is the normal mode or the high density mode (S507). When the image forming mode is the normal mode, the CPU501 reads the travel distance threshold Wth in the normal mode from the DT memory m2₁(S508). Subsequently, the CPU501 advances the latest post-addition developing roller by a distance HT_nTravel distance threshold Wth from normal mode₁Comparing and determining the bestNew step-up post developer roller travel distance HT_nWhether or not the travel distance threshold Wth in the normal mode has been exceeded₁(S509). Further, the developing roller travel distance HT after the latest step-up_nHas exceeded the travel distance threshold Wth in the normal mode₁At this time, the CPU501 advances the latest post-addition developing roller by the distance HT_nAnd writes to the DT memory m2 (S511). Subsequently, the CPU501 notifies the user that the developing cartridge 200 has reached its life via the external I/F504 using the notification unit (S512). Although a main body display unit such as a monitor or an audio speaker is conceivable as the notification unit, the notification unit is not limited thereto, and for example, a message may be transmitted to an external apparatus such as a PC connected to the image forming apparatus.

In S509, although the life of the developing roller 4 is the travel distance threshold Wth in the normal mode stored in the DT memory m2 is used₁The method is deterministic, but not limiting. Travel distance threshold value Wth in high density mode₂And the developing roller life threshold correction coefficient C1 in the normal mode may be stored in the DT memory m 2. In S508, the CPU501 may read the travel distance threshold Wth in the high density mode₂And a developing roller life threshold value correction coefficient C1 in the normal mode, and a travel distance threshold value Wth in the normal mode is obtained using the following calculation formula_1-1。

Wth_1-1＝Wth₂×C1

Subsequently, in S509, the CPU501 may advance the latest post-addition developing roller by the distance HT_nTravel distance threshold Wth from normal mode_1-1The comparison is made, and the latest after-addition developing roller travel distance HT is determined_nWhether or not the travel distance threshold Wth in the normal mode has been exceeded_1-1. Travel distance threshold Wth in normal mode_1-1Is an example of the third life threshold value relating to the life of the developing roller 4. It should be noted that the travel distance threshold value Wth in the normal mode is calculated using the developing roller life threshold value correction coefficient C1 in the normal mode_1-1The method of (3) is similarly applied to fig. 7A to 9B which will be described later. Table 2 below shows the high concentration modeTravel distance threshold Wth₂And a developing roller life threshold correction coefficient C1 in the normal mode. However, the numerical values shown in table 2 are merely examples, and are not limiting.

[ Table 2]

Travel distance threshold value Wth in high density mode₂	2400000[mm]
		Developing roller life threshold correction coefficient C1 in normal mode	1.25

Although in the description given above, the CPU501 performs the development roller travel distance HT on the basis of the latest post-addition development roller travel distance_nWhether or not the travel distance threshold Wth in the normal mode has been exceeded₁The life of the developing roller 4 is determined, but the determination by the CPU501 is not limited thereto. Specifically, in S509, the CPU501 may obtain the developing roller remaining life DP1 in the normal mode using the following calculation formula, and determine the life of the developing roller 4 based on whether the developing roller remaining life DP1 in the normal mode has fallen below 0 or a prescribed value.

DP1[％]＝(1-HT_n/Wth₁)×100

Further, the CPU501 may use the travel distance threshold Wth in the normal mode_1-1The developing roller remaining life DP1 is calculated. The method of using the developing roller remaining life DP1 in the normal mode is similarly applicable to fig. 8A and 8B which will be described later.

In S509, the developing roller travel distance HT after the latest increment_nDoes not exceed the travel distance threshold Wth in the normal mode₁At this time, the CPU501 advances the latest post-addition developing roller by the distance HT_nWrite to DT memory m2 to updateProgressive post developer roller travel distance HT_n(S510). Further, the image forming apparatus 100 performs preparation for the next image formation. When using Wth in S509 and S510_1-1When the CPU501 executes and uses Wth₁The processing at the time is similar to that at the time.

When the image forming mode is the high density mode, the CPU501 reads the travel distance threshold Wth in the high density mode from the DT memory m2₂(S513). Subsequently, the CPU501 advances the latest post-addition developing roller by a distance HT_nWith a travel distance threshold Wth in the high density mode₂The comparison is made, and the latest after-addition developing roller travel distance HT is determined_nWhether or not the travel distance threshold Wth in the high density mode has been exceeded₂(S514). Further, the developing roller travel distance HT after the latest step-up_nHas exceeded the travel distance threshold Wth in the high density mode₂At this time, the CPU501 advances the latest post-addition developing roller by the distance HT_nAnd writes to the DT memory m2 (S516). Subsequently, the CPU501 notifies the user that the developing cartridge 200 has reached its life via the external I/F504 using the notification unit (S512). After executing the notification processing in S512, the CPU501 may permit or prohibit the image forming apparatus 100 from performing an image forming operation in the normal mode according to an instruction from the user. Alternatively, after executing the notification processing in S512, the CPU501 may allow or prohibit the image forming apparatus 100 from performing the image forming operation in the normal mode regardless of an instruction from the user.

Although the travel distance threshold Wth in the high density mode stored in the DT memory m2 is used in the description given above₂The life of the developing roller 4 is determined, but the method is not limited. Travel distance threshold Wth in normal mode₁And the developing roller life threshold correction coefficient C2 in the high density mode may be stored in the DT memory m 2. In S513, the CPU501 may read the travel distance threshold Wth in the normal mode₁And a developing roller life threshold value correction coefficient C2 in the high density mode, and a travel distance threshold value Wth in the high density mode is obtained using the following calculation formula_2-1。

Wth_2-1＝Wth₁×C2

Subsequently, in S514, the CPU501 may advance the latest post-addition developing roller by the distance HT_nWith a travel distance threshold Wth in the high density mode_2-1The comparison is made, and the latest after-addition developing roller travel distance HT is determined_nWhether or not the travel distance threshold Wth in the high density mode has been exceeded_2-1. Travel distance threshold value Wth in high density mode_2-1Is an example of the fourth life threshold value relating to the life of the developing roller 4. It should be noted that the travel distance threshold value Wth in the high density mode is calculated using the developing roller life threshold value correction coefficient C2 in the high density mode_2-1The method of (3) is similarly applied to fig. 7A to 9B which will be described later. Table 3 below shows the travel distance threshold Wth in the normal mode₁And a developing roller life threshold correction coefficient C2 in the high density mode. However, the numerical values shown in table 3 are merely examples and are not limiting.

[ Table 3]

Travel distance threshold Wth in normal mode₁	3000000[mm]
		Developing roller life threshold correction coefficient C2 in high density mode	0.8

Although in the description given above, the CPU501 performs the development roller travel distance HT on the basis of the latest post-addition development roller travel distance_nWhether or not the travel distance threshold Wth in the high density mode has been exceeded₂The life of the developing roller 4 is determined, but the determination by the CPU501 is not limited thereto. Specifically, in S514, the CPU501 may obtain the developing roller remaining life DP2 using the following calculation formula and based on the displayWhether the developing roller remaining life DP2 has fallen below 0 or a prescribed value determines the life of the developing roller 4.

DP2[％]＝(1-HT_n/Wth₂)×100

Further, the CPU501 may use the travel distance threshold Wth in the high density mode_2-1The developing roller remaining life DP2 is calculated. The method of using the developing roller remaining life DP2 in the high density mode is similarly applicable to fig. 8A and 8B which will be described later.

Further, the reference travel distance threshold value Wth_RThe developing roller life threshold correction coefficient C1 in the normal mode and the developing roller life threshold correction coefficient C2 in the high density mode may be stored in the DT memory m 2. Reference travel distance threshold Wth_RIs an example of the reference life threshold value related to the life of the developing roller 4.

In S508, the CPU501 may read the reference travel distance threshold Wth_RAnd a developing roller life threshold value correction coefficient C1 in the normal mode, and obtains a travel distance threshold value Wth in the normal mode using the following calculation formula_1-2。

Wth_1-2＝Wth_R×C1

Subsequently, in S509, the CPU501 may advance the latest post-addition developing roller by the distance HT_nTravel distance threshold Wth from normal mode_1-2The comparison is made, and the latest after-addition developing roller travel distance HT is determined_nWhether or not the travel distance threshold Wth in the normal mode has been exceeded_1-2. Travel distance threshold Wth in normal mode_1-2Is an example of the third life threshold value relating to the life of the developing roller 4. It should be noted that the travel distance threshold Wth in the normal mode is used_1-2The method of (3) is similarly applied to fig. 7A to 9B which will be described later.

In S513, the CPU501 may read the reference travel distance threshold Wth_RAnd a developing roller life threshold value correction coefficient C2 in the high density mode, and a travel distance threshold value Wth in the high density mode is obtained using the following calculation formula_2-2。

Wth_2-2＝Wth_R×C2

Subsequently, in S514, the CPU501 may advance the latest post-addition developing roller by the distance HT_nWith a travel distance threshold Wth in the high density mode_2-2The comparison is made, and the latest after-addition developing roller travel distance HT is determined_nWhether or not the travel distance threshold Wth in the high density mode has been exceeded_2-2. Travel distance threshold value Wth in high density mode_2-2Is an example of the fourth life threshold value relating to the life of the developing roller 4. It should be noted that the travel distance threshold Wth in the high density mode is used_2-2The method of (3) is similarly applied to fig. 7A to 9B which will be described later.

In S514, when the latest after-development-roller travel distance HT as the total after-correction development-roller travel distance_nDoes not exceed the travel distance threshold Wth₂At this time, the CPU501 advances the latest post-addition developing roller by the distance HT_nWrite to DT memory m2 to update the post-increment developer roller travel distance HT_n(S515). Further, the image forming apparatus 100 performs preparation for the next image formation.

Meanwhile, after receiving the image information based on the print data (S517), the CPU501 measures the video count value VC with the video count measuring section 305 and calculates the total video count value VCt (S518). Subsequently, the CPU501 calculates the remaining toner amount TP (S519), and determines whether the remaining toner amount TP is small, or, in other words, whether the remaining toner amount TP is equal to or less than 0% (whether the remaining toner amount TP is equal to or lower than a prescribed threshold remaining amount) (S520). When the remaining toner amount TP has reached 0% or less, the CPU501 writes the accumulated video count value VCr into the DT memory m2(S522), and notifies the user that the developing cartridge 200 has reached its life (S512). Meanwhile, when the remaining toner amount TP does not reach 0% or less, the CPU501 writes the accumulated video count value VCr into the DT memory m2 (S521). Further, the image forming apparatus 100 performs preparation for the next image formation.

Although the calculation of the remaining toner amount TP has been described as a method of determining whether the remaining toner amount is small, the method is not limiting. For example, since the total video count value VCt itself indicates toner consumption, the CPU501 can determine whether the total video count value VCt exceeds a prescribed threshold value set in advance and determine whether the remaining toner amount is small. Further, although the remaining toner amount detection method according to the video counting system has been described as an example, this example is not limitative. For example, a remaining amount detection system using a capacitor, a light-transmitting remaining amount detection system, or a combination thereof may be used. Specifically, when the remaining toner amount acquired by the video counting system is equal to or less than the prescribed remaining amount, any one of the capacitance system and the light transmission system may be used. In other words, a configuration may be adopted in which a more appropriate remaining amount acquisition method is selected according to the degree of the remaining toner amount. It should be noted that the capacitance system refers to a method of acquiring the amount of toner 9 based on the detected change in capacitance using an electrode whose detected capacitance changes in accordance with the change in state of toner 9 inside the developer storage chamber (for example, by sticking a conductive member on the inner wall of the chamber). Since this is a conventional and known method, a detailed description thereof will be omitted. Further, the light transmission system refers to a system that uses a light source that irradiates the inside of the developer storage chamber with light and a light receiving portion that receives the light that has passed through the inside of the chamber and acquires the amount of toner 9 based on a change in the light receiving state of the light receiving portion. Since this method is also conventional and known, a detailed description thereof will be omitted. Similar descriptions also apply to the flowcharts that will be described later.

In the first embodiment in which this series of flowcharts is to be executed, the travel distance threshold Wt of the developing roller 4 is set according to the image forming mode. Therefore, the life of the developing cartridge 200 can be appropriately determined and notified to the user. Further, by also using the detection result of the remaining toner amount, the fact that the amount of toner inside the developing cartridge 200 is almost zero is also detected. Therefore, not only the life of the developing roller 4 due to the deterioration of the energization but also the life of the developing cartridge 200 based on the remaining amount of the toner 9 can be notified in combination, and the user can be notified of the life of the developing cartridge 200 more appropriately.

First replacement developing cartridge life determining sequence

In the description of fig. 6A and 6B, a method is described in which the post-correction developing roller travel distance Hu is added in increments to HT corresponding to the previous total post-correction developing roller travel distance_n-1The latest post-addition developing roller travel distance (total travel distance) HT is obtained as necessary_nTo determine the life of the developing roller 4. However, this method is not limiting. For example, the CPU501 subtracts the corrected developing roller travel distance Hu in increments from the developing roller travel distance TD (total distance) stored in the DT memory m2 as an initial value at the time of starting to use the developing cartridge 200. Thus, the travelable distance HT 'can be calculated'_nAs a lifetime determination value for determining the lifetime of the developing roller 4. It should be noted that HT₀Matching the developing roller travelable distance TD as an initial value.

HT'_n＝HT'_n-1-Hu

Hereinafter, the developing cartridge life determining sequence according to the decrementing process of the CPU501 will be described in detail with reference to the flowcharts shown in fig. 7A and 7B. First, since the processes of S601 to S605 in fig. 7A are similar to the processes of S501 to S505 described with reference to fig. 6A, detailed description thereof will be omitted. Next, from the initial value (developing roller travelable distance TD) stored in the DT memory m2 or the previous travelable distance HT'_n-1The corrected developing roller travel distance Hu is subtracted one by one to calculate the latest travel distance HT'_n(S606). Latest distance to travel HT'_nCorresponding to the lifetime determination value.

Since the processes of S607 and S608 in fig. 7B are similar to those of S507 and S508 described with reference to fig. 6B, a detailed description thereof will be omitted. Subsequently, CPU501 will update the latest travelable distance HT'_nTravel distance threshold Wth from normal mode₁A comparison is made and the latest distance to travel HT 'is determined'_nWhether or not it has fallen below the travel distance threshold value Wth in the normal mode₁(S609). When the CPU501 determines the travelable distance HT 'in S609'_nHas fallen below a travel distance threshold Wth in the normal mode₁At time, CPU501 will decrement the distance to travel after HT'_nWriting into DT memory m2 (S611). Subsequently, the CPU501 notifies the user that the developing cartridge 200 has reached its life via the external I/F504 using the notification unit (S612).

In S609, although CPU501 is based on the travelable distance HT'_nWhether or not it has fallen below the travel distance threshold value Wth in the normal mode₁The life of the developing roller 4 is determined, but the determination by the CPU501 is not limited thereto. Specifically, in S609, the CPU501 may obtain the developing roller remaining life DP1 'in the normal mode using the following calculation formula, and determine the life of the developing roller 4 based on whether the developing roller remaining life DP1' in the normal mode has fallen below 0 or a prescribed value.

DP1'[％]＝(HT'_n/Wth₁)×100

The method of using the developing roller remaining life DP1' in the normal mode is similarly applicable to fig. 9A and 9B which will be described later.

In S609, when the latest travelable distance HT'_nHas not fallen below the travel distance threshold Wth in the normal mode₁While, CPU501 will have the latest distance HT'_nWrite to DT memory m2 to update travelable distance HT'_n(S610). Further, the image forming apparatus 100 performs preparation for the next image formation.

Since the process of S613 in fig. 7B is similar to the process of S513 described with reference to fig. 6B, a detailed description thereof will be omitted. Subsequently, CPU501 will update the latest travelable distance HT'_nWith a travel distance threshold Wth in the high density mode₂A comparison is made and the latest distance to travel HT 'is determined'_nWhether or not it has fallen below the travel distance threshold value Wth in the high density mode₂(S614). When the CPU501 determines the travelable distance HT 'in S614'_nHas fallen below a travel distance threshold value Wth in the high density mode₂At time, CPU501 will decrement the distance to travel after HT'_nAnd writes to the DT memory m2 (S616). Subsequently, the CPU501 notifies the user that the developing cartridge 200 has reached its life via the external I/F504 using the notification unit (S612). After the notification processing is executed in S612, the CPU501 may allow or prohibit the image forming apparatus 100 from being normal according to an instruction from the userThe image forming operation is performed in the mode. Alternatively, after executing the notification processing in S612, the CPU501 may allow or prohibit the image forming apparatus 100 from performing the image forming operation in the normal mode regardless of an instruction from the user.

In S614, when the latest travelable distance HT'_nHas not fallen below the travel distance threshold value Wth in the high density mode₂While, CPU501 will have the latest distance HT'_nWrite DT memory m2 to update travelable distance HT'_n(S615). Further, the image forming apparatus 100 performs preparation for the next image formation. Since other processes are similar to those in the flowcharts shown in fig. 6A and 6B, detailed descriptions thereof will be omitted.

In S614, although CPU501 is based on the travelable distance HT'_nWhether or not it has fallen below the travel distance threshold value Wth in the high density mode₂The life of the developing roller 4 is determined, but the determination by the CPU501 is not limited thereto. Specifically, in S614, the CPU501 may obtain the developing roller remaining life DP2 'in the high density mode using the following calculation formula, and determine the life of the developing roller 4 based on whether the developing roller remaining life DP2' in the high density mode has fallen below 0 or a prescribed value.

DP2'[％]＝(HT'_n/Wth₂)×100

The method of using the developing roller remaining life DP2' in the high density mode is similarly applicable to fig. 9A and 9B which will be described later.

It should be noted that the frequency at which the processing of S604 to S616 is to be performed is not limited to a specific frequency. For example, the processes of S604 to S616 may be performed every second with respect to the travel distance Wu measured by the CPU501 as needed. Alternatively, the processing of S604 to S616 may be performed with respect to the travel distance Wu measured from the start of the print job each time the print job is completed. Further, the processing of S604 to S616 may be executed each time a prescribed number of a plurality of print jobs are completed. The description similarly applies to the previously described processes of S504 to S516 shown in fig. 6A and 6B.

Second replacement developing cartridge life determining sequence

In the description of fig. 6A, 6B, 7A, and 7B given above, the CPU501 is described as updating the post-addition developing roller travel distance HT at a prescribed frequency as needed_nAnd a travelable distance HT'_nAnd determines whether the developing cartridge 200 has reached its life. However, a similar effect may be produced by other lifetime determination sequences.

For example, the total developing roller travel distance Wt in the normal mode may be stored separately₀And the total travel distance Wt of the developing roller in the high density mode₁And CPU501 may be based on the stored Wt₀And Wt₁The life of the developing cartridge 200 is determined. Among suffixes of Wt, "0" represents the normal mode, and "1" represents the high density mode. Hereinafter, this aspect will be described in detail with reference to the flowcharts shown in fig. 8A and 8B.

First, since the processes of S701 to S703 in fig. 8A are similar to the processes of S501 to S503 described with reference to fig. 6A, a detailed description thereof will be omitted. Next, the CPU501 updates Wt based on the image forming mode selected in S702 and the travel distance Wu measured in S703₀Or Wt₁(S704). For example, when the image forming mode selected in S702 is the high density mode, the CPU501 adds the travel distance Wu measured in S703 to the developing roller total travel distance Wt₁And acquires the latest Wt₀And Wt₁. In this case, Wt₀Corresponding to a first total value obtained by adding, in increments, first driving amount information as the travel distance Wu measured in the normal mode, and Wt₁These terms will be used in the following description, corresponding to a second total value obtained by adding second driving amount information, which is the travel distance Wu measured in the high concentration mode, in increments.

Next, the CPU501 reads the developing roller travel distance correction coefficient k according to the image forming mode from the DT memory m2 (S705). Further, the CPU501 calculates the corrected developing roller travel distance Hu in the normal mode based on the developing roller travel distance correction coefficient k read in S705, respectively₀And the corrected developing roller travel distance Hu in the high density mode₁(S706). For example, when the developing roller travel distance correction coefficient k for the normal mode is 1 and the developing roller travel distance correction coefficient k for the high density mode is 1.5, the CPU501 calculates Hu₀And Hu₁So that Hu₀＝Wt₀× 1 and Hu₁＝Wt₁× 1.5.5. subsequently, the calculated Hu is used₀And Hu₁CPU501 according to H_t＝Hu₀+Hu₁The total travel distance Ht is calculated (S707). Since the processes of S708 and S709 in fig. 8B are similar to the processes of S507 and S508 described with reference to fig. 6B, a detailed description thereof will be omitted. Subsequently, the CPU501 determines whether the calculated total travel distance Ht exceeds the travel distance threshold Wth in the normal mode₁(S710). In S711 and S712, the CPU501 updates the first total value Wt in S704₀And a second total value Wt₁Write to DT memory m 2.

Since the processes of S713 and S714 in fig. 8B are similar to the processes of S512 and S513 described with reference to fig. 6B, a detailed description thereof will be omitted. Next, the CPU501 determines whether the calculated total travel distance Ht exceeds the travel distance threshold Wth in the high density mode₂(S715). In S716 and S717, the CPU501 updates the first total value Wt in S704₀And a second total value Wt₁Write to DT memory m 2. Since the processing of the other steps is as described with reference to fig. 6A and 6B, detailed description will be omitted here.

Third replacement developing cartridge life determining sequence

The flowcharts described with reference to fig. 8A and 8B may be further changed, and the second total value Wt in the high density mode may be subtracted from the developing roller travelable distance TD as an initial value₁And a first total value Wt₀The life of the developing cartridge 200 is determined. Hereinafter, this aspect will be described in detail with reference to the flowcharts shown in fig. 9A and 9B.

Since the processes of S801 to S806 in fig. 9A are similar to those of S701 to S706 described with reference to fig. 8A, detailed description thereof will be omitted. Next, the CPU501 subtracts the first total value Wt from the developing roller travelable distance TD as an initial value₀And a second total value Wt₁And calculates the travelable distance Ht' (S807).

Ht'＝TD-(Hu₀+Hu₁)

Since the processes of S808 and S809 in fig. 9B are similar to the processes of S507 and S508 described with reference to fig. 6B, a detailed description thereof will be omitted.

Next, the CPU501 determines whether the calculated travelable distance Ht' exceeds the travel distance threshold Wth in the normal mode₁(S810). In S811 and S812, the CPU501 updates the first total value Wt updated in S804₀And a second total value Wt₁Write to DT memory m 2.

Since the processes of S813 and S814 in fig. 9B are similar to those of S512 and S513 described with reference to fig. 6B, a detailed description thereof will be omitted. Next, the CPU501 determines whether the calculated travelable distance Ht' falls below the travel distance threshold Wth in the high density mode₂(S815). In S816 and S817, the CPU501 updates the first total value Wt in S804₀And a second total value Wt₁Write to DT memory m 2. Since the processing of the other steps is as described with reference to fig. 6A and 6B, detailed description will be omitted here.

For example, in fig. 6A and 6B described above, the CPU501 sets the travel distance threshold Wth in the normal mode₁(first lifetime threshold) and travel distance threshold Wth in high concentration mode₂Each of the (second life threshold) values is compared with the total developing roller travel distance HTn after the correction. Subsequently, based on the comparison result, the CPU501 determines the life of the developing cartridge 200 in each mode. Further, for example, in the flowcharts shown in fig. 8A and 8B, the CPU501 sets the travel distance threshold Wth in the normal mode₁(first lifetime threshold) and travel distance threshold Wth in high concentration mode₂Each of the (second life thresholds) is compared with the total travel distance Ht. Subsequently, based on the comparison result, the CPU501 determines the life of the developing cartridge 200 in each mode. In both flowcharts, the travel distance threshold (lifetime threshold) for each mode is used. However, this aspect is not limiting.

For example, one lifetime threshold Wth may be used, in which case the CPU501 may read the lifetime threshold from the DT memory m2 and calculate and prepare the total travel distance for separation for the normal mode and the high density mode, respectively. Hereinafter, a case where the CPU501 reads one travel distance threshold Wth from the DT memory m2 will be described.

First, the CPU501 acquires the total developing roller travel distance HTn (first life determination value) as the calculation result of step S506. furthermore, the CPU501 employs, as the total developing roller travel distance at high concentration, the total developing roller travel distance HTn '(second life determination value) obtained by multiplying the total developing roller travel distance HTn (first life determination value) by the correction coefficient D1, for example, when Wth is 3000000[ mm ], HTn is 2500000[ mm ], and D1 is 1.25, the total developing roller travel distance at high concentration HTn' is HTn × D1 is 2500000[ mm ] × 1.25 is 3125000[ mm ]. in other words, when Wth < 3125000[ mm ], the CPU 200 has determined that the developing cartridge 200 has reached its life with respect to the high concentration mode, even in the case of the flow chart shown in fig. 8A and 8B, it can produce a similar effect by multiplying the CPU501 by the step S1 in step S707.

In other words, the DT memory m2 stores a lifetime threshold Wth (travel distance threshold Wth). Further, the CPU501 obtains a first life determination value in the normal mode (first mode) and a second life determination value in the high density mode (second mode) from the developing roller travel distance HTn as the life determination value obtained according to the addition processing in S506 shown in fig. 6A. Alternatively, the developing roller travel distance HTn itself may be used as the first life determination value. Subsequently, the CPU501 compares the life threshold value Wth stored in the DT memory m2 with the first life determination value, and determines whether the latest first life determination value has exceeded the life threshold value Wth. Further, the CPU501 compares the life threshold value Wth stored in the DT memory m2 with the second life determination value, and determines whether the latest second life determination value has exceeded the life threshold value Wth. It should be noted that various processes after the CPU501 determines that each life determination value exceeds the life threshold Wth are similar to those described above, and a detailed description thereof will be omitted.

Further, in the case of the flowcharts shown in fig. 7A and 7B, the CPU501 employs the travelable distance HT 'n calculated in step S606 for the normal mode, and calculates the travelable distance (HT' n) 'at high density based on the travelable distance HT' n. More specifically, when the correction coefficient is represented by E1, the CPU501 may adopt a value obtained by subtracting E1 from the travelable distance HT ' n as the travelable distance at high density (HT ' n) '. Further, in this case, one travel distance threshold value Wth (one lifetime threshold value Wth) will be compared with the travelable distance.

For example, let us assume that E1 is 600000[ mm ], the travel distance threshold Wth (lifetime threshold) is 0[ mm ], and the travelable distance HT' n (first travelable distance) calculated in step S606 is 500000[ mm ]. In this case, the travelable distance (HT 'n)' (second travelable distance) in the high density mode is (HT 'n)' -500000 [ mm ] -600000[ mm ] -100000<0 (lifetime threshold), and therefore the CPU501 determines that the developing cartridge 200 has reached its lifetime with respect to the high density mode. Meanwhile, since the travelable distance HT' n is 500000[ mm ] >0 (life threshold Wth), the CPU501 cannot determine that the developing cartridge 200 has reached its life with respect to the normal mode. It should be noted that various processes after the CPU501 determines that each life determination value exceeds the life threshold value are similar to those described above, and a detailed description thereof will be omitted.

Further, even in the case of the flowcharts shown in fig. 9A and 9B, a similar effect can be produced by subtracting E1 from the travelable distance Ht' calculated by the CPU501 in step S807.

In other words, the DT memory m2 stores a lifetime threshold Wth (travel distance threshold Wth). Further, the CPU501 calculates a first travelable distance (first lifetime determination value) corresponding to the normal mode or a second travelable distance (second lifetime determination value) corresponding to the high concentration mode based on the travelable distance Ht 'n or the travelable distance Ht' obtained in S606 of fig. 7A or S807 of fig. 9A. The CPU501 obtains a second travelable distance (second life determination value) by, for example, subtracting E1 from the first travelable distance (first life determination value). Alternatively, the first travelable distance (first life determination value) may be the travelable distance Ht 'n or the travelable distance Ht' itself obtained in S606 of fig. 7A or in S807 of fig. 9A.

Further, the CPU501 compares each travelable distance with one travel distance threshold value Wth (lifetime threshold value Wth) stored in the DT memory m2, and determines whether each travelable distance (each lifetime determination value) has fallen below the travel distance threshold value Wth. For example, the travel distance threshold Wth may be set such that Wth becomes 0. It should be noted that various processes after the CPU501 determines that each life determination value (each travelable distance) falls below the life threshold Wth are similar to those described above, and a detailed description thereof will be omitted.

Specific examples

In the present embodiment, the developing roller travel distance correction coefficient k is changed in accordance with the remaining toner amount TP. In other words, as shown in table 4, the developing roller travel distance correction coefficient k is divided into a plurality of correction coefficients (k1 to k3) according to the range of the remaining toner amount TP. Further, the CPU501 can also use a correction coefficient divided according to the remaining toner amount TP as the developing roller travel distance correction coefficient k. A plurality of correction coefficients are stored in the DT memory m2, for example, and read by the CPU501 as appropriate. Further, the correction coefficients divided according to the remaining toner amount TP in table 4 may be applied only to the normal mode or the high density mode, or may be applied to both modes. Although the remaining toner amount TP in table 4 is divided into three parts, the number of divisions is not limited thereto. For example, the remaining toner amount TP may be more finely divided into five portions. Further, the correction coefficient may be continuously calculated and used according to the magnitude of the value of the remaining toner amount TP. When the remaining toner amount TP is replaced with the cumulative toner usage amount, similar division may be applied.

[ Table 4]

Further, in table 4, although the case where the developing roller travel distance correction coefficient k is changed according to the remaining toner amount TP has been described, this is not restrictive. The developing roller travel distance correction coefficient k may be changed according to the cumulative number of revolutions of the developing roller 4, the cumulative rotational time of the developing roller 4, or the amount of toner used, or a combination thereof may be used. The developing roller travel distance correction coefficient k only needs to be appropriately determined in accordance with the change of the parameter contributing to the deterioration of the developing roller 4 used.

Fig. 10A, 10B, and 10C are diagrams illustrating a relationship between the remaining toner amount TP and the remaining life of the developing roller 4 when printing is performed using the image forming apparatus 100 while changing the print area (print percentage) to be printed on one sheet of the recording material 12 (consumption of toner 9 per sheet). In each graph, the ordinate indicates the remaining toner amount TP [% ], and the abscissa indicates the developing roller remaining life DP [% ]. In each figure, a region 1 indicates a region to which the developing roller travel distance correction coefficient k1 is applied, a region 2 indicates a region to which the developing roller travel distance correction coefficient k2 is applied, and a region 3 indicates a region to which the developing roller travel distance correction coefficient k3 is applied. When the corrected developing roller travel distance Hu is calculated, which developing roller travel distance correction coefficient k to use is determined based on which region the remaining toner amount TP belongs to. Further, in each graph, a solid line indicates a trend of the developing roller remaining life DP when the correction of the travel distance of the developing roller 4 is performed, and a broken line indicates a trend of the developing roller remaining life DP when the correction of the travel distance of the developing roller is not performed.

Fig. 10A shows a case where printing is performed at a constant print percentage of about 1%. In the case of fig. 10A, since the solid line and the broken line always exist in the 1-zone, the developing roller travel distance correction coefficient k1 is applied to 1.0. Therefore, the developing roller remaining life DP indicated by the solid line and the uncorrected developing roller remaining life DP indicated by the broken line overlap each other. Further, at the time point (point a1) at which the developing roller remaining life DP reaches 0%, notification of the life of the developing cartridge 200 is performed.

Fig. 10B shows a case where printing is performed at a constant print percentage of about 1% to 2%. In the case of fig. 10B, since the solid line and the broken line exist in the 1 region until the remaining toner amount TP reaches 40%, the developing roller travel distance correction coefficient k1 is applied to 1.0. When the remaining toner amount TP is in the range of 40% to 21%, since the solid line and the broken line exist in the 2-zone, the developing roller travel distance correction coefficient k2 is 1.3. The gradient of the solid line changes from point B1 (remaining toner TP ═ 40%). In other words, when the correction of the travel distance W of the developing roller 4 is performed, the rate of increase in the travel distance of the developing roller 4 rises when the remaining toner amount TP is in the range of 40% to 21%. Further, when the correction of the travel distance of the developing roller 4 is performed, at the point of time (point a2) when the remaining toner amount TP reaches 20%, the developing roller remaining life DP reaches 0%, and the notification of the life of the developing cartridge 200 is performed. At the same time, the gradient of the dashed line has not changed. In other words, when the correction of the travel distance W of the developing roller 4 is not performed, the rate of increase in the travel distance of the developing roller 4 is constant regardless of the remaining toner amount TP.

Fig. 10C shows a case where printing is performed at a constant print percentage of about 7% to 8%. In the case of fig. 10C, since the solid line and the broken line exist in the 1 region until the remaining toner amount TP reaches 41%, the developing roller travel distance correction coefficient k1 is applied to 1.0. When the remaining toner amount TP falls below 41%, since the solid line and the broken line exist in the 2-zone, the developing roller travel distance correction coefficient k2 is 1.3. When the remaining toner amount TP falls below 21%, since the solid line and the broken line exist in the 3-zone, the developing roller travel distance correction coefficient k3 is applied to 5.0. The gradient of the solid line changes from point B6 (remaining toner amount TP ═ 40%) and point B7 (remaining toner amount TP ═ 20%). In other words, when the correction of the travel distance of the developing roller 4 is performed, the rate of increase of the travel distance of the developing roller 4 rises when the remaining toner amount TP is in the range of 40% to 21%, and the rate of increase of the travel distance of the developing roller 4 further rises when the remaining toner amount TP is in the range of 20% to 0%. Further, when the correction of the travel distance of the developing roller 4 is performed, the notification of the lifetime of the developing cartridge 200 is performed at the point of time (point B8) when the remaining toner amount TP reaches 0%.

Fig. 10A, 10B, and 10C are organized to show a specific example of the respective cases shown in fig. 11, a developing roller life line α connecting a point a1 in fig. 10A, a point B2 in fig. 10B, and a point B5 in fig. 10C is shown in fig. 11, the developing roller life line α is a line indicating the life of the developing cartridge 200 in the case where correction of the travel distance of the developing roller 4 is not performed, as shown in fig. 11, in the case where the remaining life of the developing roller 4 is short (the travel distance of the developing roller 4 is long) and the remaining toner amount TP is small, or, in other words, before the remaining life of the developing roller 4 reaches 0%, a developing roller life line α has been drawn because, when the travel distance of the developing roller 4 is long and the remaining amount of the toner 9 is small, adhesion of the toner 9 to the developing roller 4 increases and a control failure occurs in a region β shown in fig. 11, therefore, by performing correction of the travel distance of the developing roller 4, the life of the developing cartridge 200 may be set before reaching the region β.

For example, the travel distance threshold Wth in the normal mode may be set₁And a travel distance threshold Wth in the high density mode₂Set to the values shown in table 5.

[ Table 5]

Information forming mode	Distance of travel threshold
		Normal mode	Wth₁＝3000000[mm]
High concentration mode	Wth₂＝2400000[mm]

High concentration dieTravel distance threshold Wth of formula₂Is set lower than a travel distance threshold Wth in a normal mode₁Because, as described earlier, image density unevenness due to banding is more likely to occur in the high density mode.

In other words, in the normal mode, the developing cartridge 200 may be used up to the developing roller life line α (solid line), while in the high density mode, the developing cartridge 200 may be used up to the developing roller life line Z (dotted line) in accordance with the image forming mode.

As described above, by setting the travel distance threshold values respectively according to the image forming modes, the life notification matching the timing at which the image defect occurs can be performed for each mode, and the life of the developing cartridge 200 can be notified without causing adverse image effects in each mode.

Although the cartridge configuration divided into the developing cartridge 200 and the drum cartridge 210 has been described, the cartridge configuration is not limited to the present embodiment, and may include an AIO cartridge in which the developing cartridge 200 and the drum cartridge 210 are integrated with each other.

Although the function for storing the life-related information is described as being provided in the nonvolatile memory of the cartridge, the storage function is not limited to the present embodiment, and the information may be stored in the image forming apparatus 100 or the like. Although the normal mode and the high density mode are described as two image forming modes, the image forming mode is not limited to the present embodiment and the image forming apparatus 100 may also have a plurality of modes.

Modification of use of developing roller travel distance correction coefficient k

Although in the description of fig. 6A to 9B, the developing roller travel distance correction in the normal modeThe positive coefficient k is described as 1 and the developing roller travel distance correction coefficient k in the high density mode is described as 1.5, but these values are not limitative. As long as the developing roller travel distance correction coefficient of the corresponding mode is matched with the travel distance threshold Wth in the normal mode₁And a travel distance threshold Wth in the high density mode₂The relationship between the ratios of (a) and (b) is maintained, other correction coefficients can be assigned to the respective modes. Hereinafter, examples are shown in table 6 and table 7.

[ Table 6]

Developing roller travel distance correction coefficient in normal mode	1.0	2.0	0.5
				Developing roller travel distance correction coefficient in high concentration mode	1.5	3.0	0.75
Distance of travel threshold in normal mode	Wth₁	2Wth₁	0.5Wth₁
				Travel distance threshold in high concentration mode	Wth₂	2Wth₂	0.5Wth₂

Further, similar descriptions apply to the relationship between the developing roller traveling distance correction coefficient and the developing roller traveling distance TD in the respective modes.

[ Table 7]

Developing roller travel distance correction coefficient in normal mode	1.0	2.0	0.5
				Developing roller travel distance correction coefficient in high concentration mode	1.5	3.0	0.75
Distance that the developing roller can travel	TD	2TD	0.5TD

In this way, although various aspects of the combination of the developing roller travel distance correction coefficient and the travel distance threshold Wth can be conceived with respect to each mode, any aspect can produce a similar effect. Specifically, the lifetime determination value may be updated by making the magnitude of the driving amount information to be added or subtracted in the normal mode in increments larger than the magnitude of the driving amount information to be added or subtracted in increments in the high density mode with respect to the same driving amount of the developing roller 4.

Further, as described previously, when the developing roller travel distance correction coefficient k is 1, the reading of the correction coefficient by the CPU501 may be skipped, whereas when a correction coefficient other than 1 is assigned, the CPU501 must read the correction coefficient. Specifically, depending on which correction coefficient is assigned to each mode, the CPU501 uses the correction coefficient only for the travel distance Wu measured in the normal mode or the high density mode, or uses the correction coefficient for both the travel distances Wu measured in the respective modes. In the case of fig. 8A, 8B, 9A, and 9B, only the first total value Wt is used₀Or a second total value Wt₁Using a correction coefficient, or a first total value Wt which has been added in successive times in each of the respective modes₀And a second total value Wt₁Both use correction coefficients. In this way, in the present embodiment, the appropriate life determination of the developing cartridge 200 can be performed by changing the manner of using the correction coefficient.

In the present embodiment, the developing roller travel distance correction coefficient k may be changed in accordance with the developing roller remaining life DP. In other words, first, as shown in table 8, the developing roller travel distance correction coefficient k is divided into a plurality of correction coefficients (k1 to k3) according to the range of the developing roller remaining life DP. Further, the CPU501 can also use a correction coefficient divided according to the developing roller remaining life DP as the developing roller travel distance correction coefficient k. A plurality of correction coefficients are stored in the DT memory m2, for example, and read by the CPU501 as appropriate. Although the developing roller remaining life DP is divided into three parts in table 8, the number of divisions is not limited thereto. For example, the developing roller remaining life DP may be more finely divided into five parts. Further, the correction coefficient may be continuously calculated and used according to the magnitude of the value of the developing roller remaining life DP. Similar division may be applied when the developing roller cumulative driving amount is substituted for the developing roller remaining life DP.

[ Table 8]

Residual life DP of the developing roller	Developing roller travel distance correction coefficient k
		100 to 51 percent	k1＝1.0
50 to 21 percent	k2＝1.7
		20 to 0 percent	k3＝2.0

Further, the correction coefficients classified according to the developing roller remaining life DP in table 8 may be applied only to the normal mode or the high density mode, or may be applied to both modes. Further, in table 8, although the case where the developing roller travel distance correction coefficient k is changed in accordance with the developing roller remaining life DP has been described, this is not restrictive. The information relating to the remaining life DP of the developing roller and the information relating to the usage amount of the developing cartridge 200 may be used in combination. The developing roller travel distance correction coefficient k only needs to be appropriately determined in accordance with the change of the parameter contributing to the deterioration of the developing roller 4 used.

Second embodiment

In the present embodiment, the correction coefficient is also stored in the O memory m1 mounted to the drum cartridge 210, and the correction coefficient is determined by combining the correction coefficient stored in the O memory m1 with the correction coefficient stored in the DT memory m2 mounted to the developing cartridge 200. As shown in fig. 13, the occurrence situation of the image density unevenness due to banding in the high density mode differs depending on the combination of the remaining life of the drum cartridge 210 and the remaining life of the developing cartridge 200. This is because, when the remaining life of the drum cartridge 210 becomes short, the surface roughness of the photosensitive drum 1 increases, and the friction coefficient generated between the developing roller 4 and the photosensitive drum 1 decreases. Specifically, the slip of the developing roller 4 is suppressed, and the occurrence of the velocity unevenness with respect to the photosensitive drum 1 is suppressed. In other words, the life of the developing cartridge 200 in the high density mode is changed according to the life of the drum cartridge 210. In view of this, correction coefficients (fourth correction coefficients) divided into a plurality according to the remaining life of the drum cartridge such as shown in table 9 are stored in the O memory m1 mounted to the drum cartridge 210. Further, by combining the fourth correction coefficient with the previously described developing roller travel distance correction coefficient to determine the final developing roller travel distance correction coefficient k, a more accurate notification of the lifetime can be issued to the user. Although the drum cartridge remaining life in table 9 is divided into three parts, the number of divisions is not limited thereto. For example, the drum cartridge remaining life may be divided into five parts more finely. Further, the correction coefficient may be continuously calculated and used according to the magnitude of the value of the remaining life of the drum cartridge. Similar division can be applied when the remaining cartridge life is replaced with the accumulated cartridge drive amount.

Further, although the correction coefficient is stored in the O memory m1 attached to the drum cartridge 210 in the present embodiment, the storage method is not limited thereto as long as the relationship between the remaining life of the drum cartridge 210 and the correction coefficient can be correctly determined. For example, information indicating the relationship between the use of the drum cartridge 210 and the correction coefficient may be stored on the image forming apparatus main body side, and the CPU501 may be configured to be able to recognize the use of the drum cartridge 210 from the O memory m 1.

[ Table 9]

Drum cartridge remaining life	Developing roller travel distance correction coefficient o
		100 to 60 percent	o1＝1.0
59 to 30 percent	o2＝1.1
		29 to 0 percent	o3＝1.2

Developing roller life calculation sequence according to the present embodiment

A sequence for calculating the developing roller traveling distance according to the present embodiment will be described. It should be noted that the description of the parts overlapping with the first embodiment will be omitted. The drum cartridge remaining life is obtained using the degree of wear of the photosensitive drum 1, wherein the degree of wear of the photosensitive drum 1 is calculated from the number of rotations of the photosensitive drum 1, the scraping rate (the film thickness) of the carrier transfer layer of the photosensitive drum 1 in the initial state stored in the O memory m1, or the like. Using table 4 and table 9, the corrected developing roller travel distance Hu is obtained by multiplying the prescribed travel distance Wu by the developing roller travel distance correction coefficient kn stored in the DT memory m2 and the developing roller travel distance correction coefficient on stored in the O memory m 1. Similar description applies to the corrected developing roller travel distance Hu described with reference to fig. 8A, 8B, 9A, and 9B₀And Hu₁。

Hu＝Wu×kn×on(n＝1，2，3)

For example, when the remaining toner amount TP is 30% and the drum cartridge remaining life is 20%, the developing roller travel distance correction coefficient k is k-k 1 × o 3-1.3 × 0.85-1.105 in this way, the developing roller travel distance correction coefficient kn (developing roller travel distance correction coefficient k after correction) that has been corrected by the developing roller travel distance correction coefficient on can be used when obtaining the post-correction developing roller travel distance Hu.

According to the present embodiment, by setting the developing roller travel distance correction coefficients respectively in accordance with the remaining drum cartridge lives, it is possible to perform life notification corresponding to the occurrence timing of an image defect. Therefore, the life of the developing cartridge 200 can be notified without causing adverse image effects in each image forming mode.

Third embodiment

In the present embodiment, the developing roller travel distance threshold is stored in the O memory m1 mounted to the drum cartridge 210. A developing roller travel distance threshold value such as shown in table 10 is stored in the O memory m1 mounted to the drum cartridge 210, and the CPU501 calculates the developing roller remaining life DP from the stored developing roller travel distance threshold value. Therefore, more accurate life notification can be made to the user. For example, a travel distance threshold Wth in a high density mode that has been divided into a plurality according to the remaining life of the drum cartridge, such as shown in Table 10₂、Wth₃And Wth₄Is stored in the O memory m1 mounted to the drum cartridge 210. Although the drum cartridge remaining life is divided into three parts in table 10, the number of divisions is not limited thereto. For example, the drum cartridge remaining life may be divided into five parts more finely. Further, the threshold value may be continuously calculated and used according to the value of the remaining life of the drum cartridge. Similar division can be applied when the remaining cartridge life is replaced with the accumulated cartridge drive amount.

Further, although the developing roller travel distance threshold is stored in the O memory m1 attached to the drum cartridge 210 in the present embodiment, the storage method is not limited to this as long as the relationship between the remaining life of the drum cartridge 210 and the developing roller travel distance threshold can be correctly determined. For example, information indicating the relationship between the use of the drum cartridge 210 and the developing roller travel distance threshold may be stored on the image forming apparatus main body side, and the CPU501 may be configured to be able to recognize the use of the drum cartridge 210 from the O memory m 1.

[ Table 10]

Developing roller travel distance calculation sequence according to the present embodiment

A sequence for calculating the travel distance of the developing roller according to the present embodiment will be described. It should be noted that descriptions of parts overlapping with the first and second embodiments will be omitted.

For example, using the drum cartridge remaining life and table 10 obtained according to the second embodiment, the CPU501 determines the travel distance threshold Wth in the high density mode_L(L ═ 2, 3, 4.) CPU501 makes a correction according to total post-correction developing roller travel distance HT_nAnd a travel distance threshold value Wth in the normal mode₁The developing roller remaining life DP1 in the normal mode is calculated. Further, the CPU501 performs the developing roller travel distance HT according to the total corrected developing roller travel distance_nAnd a travel distance threshold Wth in the high density mode_LThe developing roller remaining life DP2 in the high density mode was calculated.

DP1[％]＝(1-HT_n/Wth₁)×100

DP2[％]＝(1-HT_n/Wth_L)×100(L＝2，3，4)

For example, when the drum cartridge remaining life is 20%, the travel distance threshold Wth in the normal mode₁3000000, a travel distance threshold Wth in the high density mode_L＝Wth₄Is 2700000. Further, the developing roller remaining life DP1 in the normal mode and the developing roller remaining life DP2 in the high density mode are as follows.

DP1[％]＝(1-HT_n/3000000)×100

DP2[％]＝(1-HT_n/2700000)×100

Similar description applies to the developing roller remaining life DP1 'in the normal mode and the developing roller remaining life DP2' in the high density mode described with reference to fig. 8A and 8B. In other words, CPU501 is according to distance to travel HT'_nAnd a travel distance threshold value Wth in the normal mode₁The developing roller remaining life DP1' in the normal mode is calculated. Further, CPU501 is according to the travelable distance HT'_nAnd a travel distance threshold Wth in the high density mode_LThe developing roller remaining life DP2' in the high density mode was calculated.

DP1'[％]＝(HT'_n/Wth₁)×100

DP2'[％]＝(HT'_n/Wth_L)×100(L＝2，3，4)

As described above, by setting the developing roller travel distance thresholds respectively in accordance with the drum cartridge remaining life, it is possible to perform the life notification corresponding to the occurrence timing of the image defect. Therefore, the life of the developing cartridge 200 can be notified without causing adverse image effects in each image forming mode.

Fourth embodiment

In the present embodiment, the developing roller life threshold correction coefficient pk (k 2, 3, 4) in the high density mode is stored in the O memory m1 mounted to the drum cartridge 210.

A developing roller life threshold correction coefficient pk (fifth correction coefficient) in the high density mode according to the drum cartridge remaining life such as shown in table 11 is stored in the O memory m1 mounted to the drum cartridge 210, and the CPU501 calculates the developing roller remaining life DP according to the developing roller life threshold correction coefficient pk. Although the drum cartridge remaining life is divided into three parts in table 11, the number of divisions is not limited thereto. For example, the drum cartridge remaining life may be divided into five parts more finely. Further, the threshold value may be continuously calculated and used according to the value of the remaining life of the drum cartridge. Similar division can be applied when the remaining cartridge life is replaced with the accumulated cartridge drive amount.

[ Table 11]

Drum cartridge remaining life	Developing roller life threshold correction coefficient in high-density mode
		100 to 60 percent	P2＝0.8
59 to 30 percent	P3＝0.85
		29 to 0 percent	P4＝0.9

As shown in table 11, the shorter the remaining life of the drum cartridge, the larger the value assigned to the developing roller life threshold correction coefficient pk in the high density mode. In the present embodiment, the developing roller life threshold correction coefficient pk in the high density mode according to the remaining life of the drum cartridge is stored in the O memory m1 mounted to the drum cartridge 210. However, the storage method is not limited to this as long as the relationship between the remaining life of the drum cartridge 210 and the developing roller life threshold correction coefficient pk in the high density mode can be correctly determined. For example, information indicating the relationship between the use of the drum cartridge 210 and the developing roller life threshold correction coefficient pk in the high density mode may be stored on the image forming apparatus main body side, and the CPU501 may be configured to be able to recognize the use of the drum cartridge 210 from the O memory m 1.

Developing roller travel distance determination sequence according to the present embodiment

A sequence for determining the travel distance of the developing roller according to the present embodiment will be described. It should be noted that descriptions of parts overlapping with the first to third embodiments will be omitted.

Using the remaining life of the drum cartridge and table 11, the CPU501 determines the developing roller life threshold correction coefficient pk in the high density mode. Further, the CPU501 determines the travel distance threshold Wth in the high density mode using the following formula_k。

Wth_k＝Wth₁×pk(k＝2，3，4)

The CPU501 performs the developing roller travel distance HT according to the total corrected developing roller travel distance_nAnd a travel distance threshold value Wth in the normal mode₁The developing roller remaining life DP1 in the normal mode is calculated. Further, the CPU501 performs the developing roller travel distance HT according to the total corrected developing roller travel distance_nAnd a travel distance threshold Wth in the high density mode_kThe developing roller remaining life DP2 in the high density mode was calculated.

DP1[％]＝(1-HT_n/Wth₁)×100

DP2[％]＝(1-HT_n/Wth_k)×100(k＝2，3，4)

For example,a travel distance threshold Wth in the high density mode when the drum cartridge remaining life is 20%_kIs 2700000 (Wth)₃3000000 × 0.9.9), and the developing roller remaining lives DP1 and DP2 in the normal mode and the high density mode are as follows.

DP1[％]＝(1-HT_n/3000000)×100

DP2[％]＝(1-HT_n/2700000)×100

As described above, by setting the developing roller life threshold correction coefficient in the high density mode in accordance with the drum cartridge life, it is possible to perform the life notification corresponding to the occurrence timing of the image defect. Therefore, the life of the developing cartridge 200 can be notified without causing adverse image effects in each image forming mode.

According to the description presented above, even in an image forming apparatus having a plurality of image forming modes in which the rotational peripheral speed ratio between the photosensitive drum and the developing roller is different, the life of the developing apparatus can be appropriately determined.

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

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