JP2020112782A - Image forming apparatus - Google Patents

Abstract

To appropriately determine the life of a developing device in an image forming apparatus having a plurality of image forming modes different in rotational peripheral speed ratio between a photoconductor drum and a developing roller.SOLUTION: An image forming apparatus has a first mode and a second mode different in rotational peripheral speed ratio of a developer carrier. The image forming apparatus stores 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, on the basis of first drive amount information when the developer carrier operates in the first mode and second drive amount information when the developer carrier operates in the second mode, gradually adds the drive amount information of the developer carrier to a life determination value of the developing device or gradually reduces the drive amount information from an initial value to update the life determination value, on the basis of the first life threshold or a third life threshold and the life determination value, performs first determination on the life in the first mode, on the basis of the second life threshold or a fourth life threshold and the life determination value, performs second determination on the life in the second mode, and performs notification based on results of the determination.SELECTED DRAWING: Figure 6

Description

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, and a facsimile, which uses an electrophotographic method, an electrostatic recording method, or the like.

In an image forming apparatus such as a printer using an electrophotographic image forming method (electrophotographic process), an electrophotographic photosensitive member (hereinafter referred to as “photosensitive member”) as an image carrier is uniformly charged, and the charged photosensitive member is charged. An electrostatic image is formed on the photoreceptor by selectively exposing the body. The electrostatic image formed on the photoconductor is visualized as a toner image with toner as a developer. Then, the toner image formed on the photoconductor is transferred to a recording material such as recording paper or a plastic sheet, and heat or pressure is applied to the toner image transferred onto the recording material to form the toner image on the recording material. Image recording is performed by fixing.
Such an image forming apparatus generally requires replenishment of the developer and maintenance of various process means. In order to facilitate the developer replenishment work and the maintenance of various process means, a process in which the photoconductor, the charging means, the developing means, the cleaning means, etc. are collectively made into a cartridge and can be attached to and detached from the image forming apparatus main body. It has been put to practical use as a cartridge. According to the process cartridge system, it is possible to provide an image forming apparatus having excellent usability.
In such a process cartridge, as the number of times an image is formed increases, toner is repeatedly collected without being developed on the photosensitive drum, which is an example of the photosensitive member. Such a toner may be deteriorated due to the external additive agent being released from or embedded in the resin particles as the base of the toner due to the repeated formation of the toner image. There is. In such a case, the toner cannot obtain a desired charge amount, so that the toner adheres to a white background portion on the image, so-called fog may occur. In view of this, Japanese Patent Application Laid-Open No. 2004-242242 proposes a method in which the degree of deterioration of toner in the image forming apparatus is calculated and integrated to determine that the developing device has reached the end of its life. Further, in Patent Document 2, a method is proposed in which the optimum life of the developing device is determined in consideration of the degree of deterioration of the developing roller due to the degree of so-called filming, in which toner and external additives are deposited on the developing roller. Has been done.

Japanese Patent No. 4743273 JP, 2016-161645, A

In recent years, one of a wide variety of market demands has been made to increase the image density and expand the color tone for the purpose of obtaining a richer image. The following techniques are known for achieving the purpose. In addition to the general mode for obtaining image density, as a means for achieving high density and increased tint, there is a mode for changing the peripheral speed ratio between the photosensitive drum and the developing roller, which supplies toner to the photosensitive drum. There is a technique that is realized by increasing the amount of toner and the amount of toner on the recording medium.
It has been found by the study by the inventor that if the peripheral speed ratio between the photosensitive drum and the developing roller is increased by using this technique for printing, the deterioration of the developing roller is affected. If the developing roller deteriorates early, the volume resistance value increases, and the electric charge of the toner on the developing roller does not easily escape to the developing roller, and the toner accumulates the electric charge. As a result, for example, the charge of the toner on the developing roller becomes excessive, and the regulation by the regulation member becomes insufficient. for that reason,
So-called regulation failure may occur at an early timing, or the amount of toner on the developing roller may increase due to the regulation failure and banding due to slip between the developing roller and the photosensitive drum may occur at an early timing. That is, it is desired to notify the user of the life of the developing device at an appropriate timing.
An object of the present invention is to solve such a problem. That is, it is an object of the present invention to provide a technique capable of more appropriately determining the life of a developing device in an image forming device capable of selecting an image forming mode in which the rotation peripheral speed ratio of a photosensitive drum and a developing roller is changed.

In order to achieve the above object, the image forming apparatus of the present invention,
A rotatable image carrier,
A developing device having a developer carrier for supplying a developer to the image carrier to develop the electrostatic latent image on the image carrier,
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 first mode in which the developer bearing member has a larger peripheral speed ratio with respect to the image bearing member. An image forming apparatus having a second mode of rotating at a peripheral speed ratio of 2,
Storage means for storing a first life threshold value of the developing device corresponding to the first mode and a second life threshold value of the developing device corresponding to the second mode;
The development based on first drive amount information when the developer carrier operates in the first mode and second drive amount information when the developer carrier operates in the second mode. Control means for renewing the life judgment value by cumulatively adding or subtracting the driving amount information of the developer carrier with respect to the life judgment value of the device,
And a notification means,
The control means is
(I) based on the first life threshold and the life judgment value, or (ii) a third life threshold and the life judgment value calculated using one of the second life threshold and the reference life threshold. , A first judgment relating to the life of the first mode is performed,
(I) Based on the second life threshold and the life judgment value, or (ii) a fourth life threshold calculated using one of the first life threshold and the reference life threshold and the life judgment value. And a second judgment regarding the life of the second mode based on
The notifying means is
It is characterized in that notification is performed based on the judgment result by the control means.
Further, in order to achieve the above object, the image forming apparatus of the present invention,
A rotatable image carrier,
A developing device having a developer carrier for supplying a developer to the image carrier to develop the electrostatic latent image on the image carrier,
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 first mode in which the developer bearing member has a larger peripheral speed ratio with respect to the image bearing member. An image forming apparatus having a second mode of rotating at a peripheral speed ratio of 2,
Storage means for storing any one of a first life threshold of the developing device corresponding to the first mode, a second life threshold of the developing device corresponding to the second mode, and a reference life threshold;
Life judgment based on first drive amount information when the developer carrier operates in the first mode and second drive amount information when the developer carrier operates in the second mode Control means for calculating the value,
And a notification means,
The control means is
(I) Based on the first life threshold and the life judgment value, or (ii) a third life threshold and the life judgment value calculated using one of the second life threshold and the reference life threshold. And a first judgment regarding the life of the first mode based on
(I) Based on the second life threshold and the life judgment value, or (ii) a fourth life threshold calculated using one of the first life threshold and the reference life threshold and the life judgment value. And a second judgment regarding the life of the second mode based on
The notifying means is
It is characterized in that notification is performed based on the judgment result by the control means.
Further, in order to achieve the above object, the image forming apparatus of the present invention,
A rotatable image carrier,
A developing device having a developer carrier for supplying a developer to the image carrier to develop the electrostatic latent image on the image carrier,
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 first mode in which the developer bearing member has a larger peripheral speed ratio with respect to the image bearing member. An image forming apparatus having a second mode of rotating at a peripheral speed ratio of 2,
Storage means for storing a life threshold of the developing device;
Based on first drive amount information when the developer carrier operates in the first mode and second drive amount information when the developer carrier operates in the second mode, A first life judgment value corresponding to one mode and a control means for calculating a second life judgment value corresponding to the second mode;
And a notification means,
The control means is
Based on a comparison between the life threshold value and the first life judgment value, the notifying unit is notified of the life of the developing device in the first mode,
It is characterized in that the informing unit is informed of the life of the developing device in the second mode based on a comparison between the life threshold and the second life judgment value.

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

Schematic of image forming device Schematic of drum cartridge Schematic of developer cartridge Hardware block diagram of image forming apparatus Explanatory diagram of the relationship between the traveling distance of the developing roller, defective regulation, and banding Development cartridge life judgment sequence chart Life judgment sequence chart of another developer cartridge Life judgment sequence chart of another developer cartridge Life judgment sequence chart of another developer cartridge Relationship diagram between remaining amount of toner and remaining life of developing roller Explanatory drawing of developing roller life line The figure which shows the notification timing of the life of the developing cartridge Diagram showing the occurrence of banding in high concentration mode

MODES FOR CARRYING OUT THE INVENTION Modes for carrying out the present invention will be exemplarily described in detail below based on embodiments with reference to the drawings. However, the dimensions, materials, shapes, and relative arrangements of the components described in this embodiment should be appropriately changed depending on the configuration of the apparatus to which the invention is applied and various conditions. That is, the scope of the present invention is not intended to be limited to the following embodiments.

[Example 1]
An overall configuration of an embodiment of the electrophotographic image forming apparatus (image forming apparatus) will be described. FIG. 1 is a sectional view of the image forming apparatus 100 of this embodiment. The image forming apparatus 100 of this embodiment is a full-color laser beam printer that employs an in-line method and an intermediate transfer method. The image forming apparatus 100 can form a full-color image on a recording material (for example, recording paper, plastic sheet, cloth, etc.) according to the image information. The 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 communicatively connected to the image forming apparatus main body. The image forming apparatus 100 includes SY, SM, SC, and SK for forming images of yellow (Y), magenta (M), cyan (C), and black (K), respectively, as a plurality of image forming units. Have. In this embodiment, the image forming units SY, SM, SC, SK are arranged in a line in a direction intersecting the vertical direction.

The image forming apparatus 100 in this embodiment includes the photosensitive drum 1, the charging roller 2, the cleaning blade 6, and the drum cartridge frame 11 shown in FIG. The drum cartridge 210 is configured. Further, the developing roller 4, the toner supply roller 5, the toner amount regulating member 8, the developer chamber 20a and the developer container 22 constituting the developer accommodating chamber 20b shown in FIG. The developing cartridge 200 is used.
The above-described image forming unit includes the drum cartridge 210 (210Y, 210M, 210C, 210K) and the developing cartridge 200 (200Y, 200M, 200C, 200K). The drum cartridge 210 and the developing cartridge 200 can be attached to and detached from the image forming apparatus 100 via a mounting guide, a positioning member, and other mounting means provided in the image forming apparatus main body. In this embodiment, the drum cartridge 210 for each color and the developing cartridge 200 have the same shape, and the developing cartridge 200 for each color has yellow (Y), magenta (M), and cyan (C), respectively. , And black (K) toners are stored. In this embodiment, the configuration in which the drum cartridge 210 and the developing cartridge 200 are independently attachable and detachable is described, but the configuration in which the drum cartridge 210 and the developing cartridge 200 are integrally detachable and attachable to the image forming apparatus main body may be employed.

The photosensitive drum 1 is rotationally driven by a driving unit (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 based on image information to form an electrostatic image (electrostatic latent image) on the photosensitive drum 1. In the main scanning direction (the direction orthogonal to the conveying direction of the recording material 12), the writing of the laser exposure is performed for each scanning line from a position signal in the polygon scanner called BD. On the other hand, in the sub-scanning direction (conveying direction of the recording material 12), the recording is performed with a delay of a predetermined time from the TOP signal originating from a switch (not shown) in the recording material 12 conveying path. As a result, the laser exposure can always be performed at the same position on the photosensitive drum 1 in the four process stations Y, M, C, and K.

An intermediate transfer belt 31 as an intermediate transfer member for transferring the toner image on the photosensitive drums 1 to the recording material 12 is arranged facing the four photosensitive drums 1. The intermediate transfer belt 31 formed of an endless belt as an intermediate transfer member contacts all the photosensitive drums 1 and circulates (rotates) in the direction of arrow B (counterclockwise) in the drawing. On the inner peripheral surface side of the intermediate transfer belt 31, four primary transfer rollers 32 as primary transfer means are arranged in parallel so as to face the photosensitive drums 1. Then, a bias having a polarity opposite to the regular 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). As a result, the toner image on the photosensitive drum 1 is transferred (primary transfer) onto the intermediate transfer belt 31.

Further, on the outer peripheral surface side of the intermediate transfer belt 31, the secondary transfer roller 3 as a secondary transfer unit is provided.
3 are arranged. Then, a bias having a polarity opposite to the regular 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). As a result, the toner image on the intermediate transfer belt 31 is transferred (secondary transfer) to the recording material 12. For example, when forming a full-color image, the above-described process is sequentially performed in the image forming units SY, SM, SC, and SK, and the toner images of the respective colors are sequentially superposed and primarily transferred onto the intermediate transfer belt 31. Then, the recording material 12 is conveyed to the secondary transfer portion in synchronization with the movement of the intermediate transfer belt 31. Then, the four-color toner images on the intermediate transfer belt 31 are collectively secondarily transferred onto the recording material 12 by the action of the secondary transfer roller 33 which is in contact with the intermediate transfer belt 31 via the recording material 12. It

The recording material 12 to which the toner image is transferred is conveyed to the fixing device 34 as a fixing unit. By applying heat and pressure to the recording material 12 in the fixing device 34, the toner image is fixed on the recording material 12.

[Drum cartridge]
The configuration of the drum cartridge 210 installed in the image forming apparatus 100 of this embodiment will be described. FIG. 2 is a cross-sectional view (main cross-sectional view) of the drum cartridge 210 of the present embodiment as viewed along the longitudinal direction (rotational axis direction) of the photosensitive drum 1.
The photosensitive drum 1 is rotatably attached to the drum cartridge 210 via a bearing (not shown). The photosensitive drum 1 is rotationally driven in the direction of arrow A in the figure according to the image forming operation by receiving the driving force of the drive motor as the photosensitive drum driving means (driving source M210).

The photosensitive drum 1 uses an organic photosensitive member in which an underlayer, a high resistance layer, a carrier layer, and a carrier transfer layer, which are functional films, are sequentially coated on the outer peripheral surface of an aluminum cylinder having a diameter of 30 mm. Since the carrier transfer layer is scraped and consumed by the image forming operation, it is necessary to form a film thickness according to the life of the drum cartridge 210. In order to achieve a long service life in response to recent market demand, the thickness is set to 25 μm in this embodiment.

Further, in the drum cartridge 210, the cleaning blade 6 formed of an elastic body and the charging roller 2 is arranged so as to contact the peripheral surface of the photosensitive drum 1. Further, a drum cartridge frame 11 having a storage space for storing the toner on the photosensitive drum 1 removed by the cleaning blade 6 is provided. The charging roller 2 is applied with a sufficient bias so that an arbitrary charge can be placed on the photosensitive drum 1 from a charging bias power source (high voltage power source) 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 becomes −500V. A laser 35 is emitted from the scanner unit 30 based on image information to form an electrostatic image (electrostatic latent image) on the photosensitive drum 1. As a result of the irradiation of the laser 35, the electric charge on the surface of the photosensitive drum 1 disappears due to the carriers from the carrier generation layer, and the electric potential of the irradiation portion decreases. As a result, the irradiated portion of the laser 35 forms an electrostatic latent image having a predetermined bright portion potential (Vl) and the non-irradiated portion has a predetermined dark portion potential (Vd).

Further, the drum cartridge 210 is provided with a non-volatile memory (hereinafter referred to as an O memory m1) which is a storage unit. The O memory m1 stores information such as the number of rotations of the photosensitive drum 1 and the manufacturing number, and the usage amount of the drum cartridge can be grasped based on the information held by the O memory m1. The O memory m1 is configured to be capable of communicating (writing and reading of information) with the control unit 300 of the image forming apparatus 100 shown in FIG. 1 by non-contact or by contact via an electric contact (not shown).

[Development cartridge]
Next, the configuration of the developing cartridge 200 installed in the image forming apparatus 100 of this embodiment will be described. FIG. 3 is a sectional view (main sectional view) of the developing cartridge 200 of 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, a developer accommodating chamber 20b, a developing roller 4, a toner supply roller 5, and a developer container 22 that constitutes the developing chamber 20a and a developer accommodating chamber 20b. The developer accommodating chamber 20b is arranged below the developing chamber 20a. The toner 9 as a developer is stored in the developer storage chamber 20b. In the present embodiment, the normal charge polarity of the toner 9 is negative, and the case of using a negative charge toner will be described below. However, the present invention is not limited to the negatively chargeable toner.

Further, in the developer accommodating chamber 20b, a developer conveying member 21 for conveying the toner 9 to the developing chamber 20a is provided, and by rotating in the direction of arrow G in the figure, the toner 9 is transferred to the developing chamber 20a. Is being transported to. The developer carrying member 21 is composed of an elastic sheet-shaped member extending in the longitudinal direction of the cartridge.

In the developing chamber 20a, a developing roller 4 as a developer bearing member that comes into contact with the corresponding photosensitive drum 1 and rotates in a direction of an arrow D in the drawing by receiving a driving force of a driving motor as a developing driving unit (driving source M200). Is provided. In this embodiment, the developing roller 4 and the photosensitive drum 1 rotate so that their surfaces move in the same direction at the facing portion (contact portion). Further, the developing roller 4 is provided with a conductive elastic rubber layer having a predetermined volume resistance around a metal cored bar. Then, a sufficient bias for developing and visualizing 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, inside the developing chamber 20 a, a toner supply roller (hereinafter, simply referred to as “supply roller”) 5 that supplies the toner conveyed from the developer accommodating chamber 20 b to the developing roller 4, and a supply roller 5 supply the toner. A toner amount regulating member (hereinafter, simply referred to as “regulating member”) 8 that regulates the amount of toner coated on the developing roller 4 and imparts electric charge is arranged.

Further, the developing cartridge 200 is provided with a non-volatile memory (hereinafter, DT memory m2) which is 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 the usage amount of the developing cartridge can be grasped based on the information held by the DT memory m2. The toner remaining amount is the amount of toner remaining in the toner stored in the developing cartridge 200. The DT memory m2 is configured to be able to communicate (write and read information) with the control unit 300 of the image forming apparatus 100 in a non-contact manner or a contact via an electrical contact (not shown).

[Image forming mode]
The image forming apparatus 100 of this 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). In the second mode, the rotation peripheral speed ratio between the photosensitive drum 1 as the image bearing member and the developing roller 4 as the developer bearing member is increased while lowering the dark portion potential on the image bearing member to select high density and tint. This is an image forming mode (hereinafter referred to as a high density mode) for increasing the range. Thus, the rotational peripheral speed ratio (second peripheral speed ratio) in the second mode is larger than the rotational peripheral speed ratio (first peripheral speed ratio) in the first mode.
Table 1 below shows specific differences in control between the normal mode and the high-concentration mode in this embodiment.

表１中の暗部電位Ｖｄは、帯電ローラ２で感光ドラム１表面を帯電した後の感光ドラム１表面の電位である。また、明部電位Ｖｌは、レーザ３５が照射された後の感光ドラム１表面の電位である。現像電位Ｖｄｃは現像ローラ４に現像バイアス電源によって印加される電位である。

The dark portion potential Vd in Table 1 is the potential of the surface of the photosensitive drum 1 after charging the surface of the photosensitive drum 1 with the charging roller 2. The bright portion potential Vl is the potential of the surface of the photosensitive drum 1 after being irradiated with the laser 35. The developing potential Vdc is a potential applied to the developing roller 4 by the developing bias power source.

The rotational peripheral speed ratio in this 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 rotation peripheral speed of the photosensitive drum 1 is set to 200 mm/sec, and the rotation peripheral speed of the developing roller 4 is set to 280 mm/sec. On the other hand, in the high density mode, the rotation peripheral speed of the photosensitive drum 1 is set to 100 mm/sec and the rotation peripheral speed of the developing roller 4 is set to 250 mm/sec. Here, the reason why the rotational peripheral speed of the photosensitive drum 1 is slowed down in the high density mode is to secure good fixing property because the amount of toner on the recording material 12 is increased. The heat applied to the recording material 12 in the fixing device 34 may be increased, but since the power consumption increases, the rotational peripheral speed of the photosensitive drum 1 is slowed in this embodiment.

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

[Toner level detection method]
Here, the toner remaining amount detecting method by the video counting method used in this embodiment will be described. FIG. 4 shows a hardware block diagram of the image forming apparatus in this embodiment. The control unit 300 of the image forming apparatus 100 performs various calculation processes to obtain a correction information obtaining unit that obtains correction amount information such as a correction distance of the developing roller 4, which will be described later, and a remaining amount obtaining unit that obtains information about the remaining amount of toner. A CPU 501 that also functions as a unit is provided. Further, a memory 502 and the like on the image forming apparatus main body side, which stores information necessary for controlling the motor drive unit 511 and the high-voltage power supply 512, are also provided. Further, the information stored in the O memory m1 of the drum cartridge 210 or the DT memory m2 of the developing cartridge 200 is input/output to/from the CPU 501 from the input/output I/F 503 via the memory communication unit 500 and exchanged with the control unit 300. Is going. Further, the control unit 300 is connected to a video count measuring unit 305 that measures a video signal output by an image forming operation.
The principle of toner remaining amount detection using video count will be described. Another control device (not shown) is arranged upstream of the control unit 300, and a laser drive signal (video signal) from the control device is branched to form a video during a period in which an electrostatic latent image is formed on the photosensitive drum. Sample the signal. The sampled video signal is input to the hardware counter in the control unit 300 to count the number of ON of the video signal ON/OFF, and the value is read by the CPU 501. The read value indicates the amount of toner consumed, and the value obtained by subtracting the count value from the predetermined initial value is used as information indicating the remaining amount of toner. Then, when the number of ONs of the video signal is divided by the number of ONs measured when a black image is printed on the area on the recording material where the image is to be printed, which is calculated to form an electrostatic latent image. Only the ratio of whether the laser is turned on can be obtained. The electrostatic latent image is formed on the portion irradiated with the laser, and the toner adheres to the portion. Therefore, the remaining toner amount can be calculated based on the lighting ratio of the laser. Note that the count by the video count measuring unit 305 specifically corresponds to the count of ON video signals for irradiating a laser beam, but the sampling cycle thereof does not have to be synchronized with the video clock of the video signal. If sampling is performed at a cycle shorter than the video clock, the video count measuring unit 305 may count pixel information asynchronously with the video clock. Then, the CPU 501 provided in the control unit 300 calculates the remaining amount of the toner 9 in the developing cartridge 200 from the measured video count value.

The video count measuring unit 305 measures pixel information (video count value VCn) of the output image. In this embodiment, one output of the recording material 12 is set as one video count value VCn. The CPU 501 calculates the remaining toner amount according to the following procedure. First, the video count value VCn measured by the video count measuring unit 305 is added to the cumulative video count value VCr stored in the DT memory m2 of the development cartridge 200 from the start of use of the development cartridge 200 to obtain the total video count value VCt. To calculate.
VCt=VCr+VCn

Next, the CPU 501 calculates the toner remaining amount TP in the developing cartridge 200 from the video count threshold value VCth stored in the DT memory m2 and the total video count value VCt.
TP[%]=(1-VCt/VCth)×100
Then, the CPU 501 writes the total video count value VCt as the cumulative video count value VCr in the DT memory m2.
Here, when the remaining toner amount TP=100%, the toner 9 in the developing cartridge 200 is in a full state, which means that the developing cartridge 200 is new. Further, when the remaining toner amount TP=0%, the remaining amount of the toner 9 in the developing cartridge 200 is almost exhausted, which indicates that the developing cartridge 200 is at the replacement timing.
In the present embodiment, the video count threshold VCth in the case where the toner remaining amount TP=0% is set such that the toner supply from the supply roller 5 to the developing roller 4 is insufficient even when a high print image such as a solid image is printed. It was set based on the remaining amount of the toner 9 which does not occur. Therefore, the actual remaining toner amount may be TP=5%, for example.

[Development roller life calculation method]
Next, a method for calculating the life of the developing roller 4 will be described. The life of the developing roller 4 is determined according to the traveling distance Wu of the developing roller 4. In the following description, the travel distance Wu will be described as an example of drive amount information indicating how much the developing roller 4 has driven. However, the drive amount information may indicate how much the developing roller 4 has driven. , Various parameters can be used. For example, it may be the total driving time of the developing cartridge 200 or the total number of rotations of the developing roller 4. Alternatively, it may be the number of printed sheets formed using the developing cartridge 200.
The image forming apparatus 100 is provided with a developing roller running distance measuring unit 302 that measures the running distance Wu of the developing roller 4, and the CPU 501 measures the developing roller running distance Wu of the developing roller 4 using the developing roller running distance correction coefficient k. The traveling distance Wu is corrected.

The developing roller running distance measuring unit 302 measures the running 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 to the photosensitive drum 1.
Wu=Td×Ps×Sr
Here, the traveling distance Wu represents how much a certain point on the surface of the developing roller 4 has advanced by 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 CPU 501 reads the developing roller travel distance correction coefficient k that is the first correction coefficient stored in the DT memory m2. The CPU 501 may read the developing roller travel distance correction coefficient k (second correction coefficient) according to the information regarding the usage amount of the developing cartridge 200. The information regarding the usage amount of the developing cartridge 200 may include information such as the cumulative rotation number of the developing roller 4, the cumulative rotation time of the developing roller 4, the toner usage amount, and the toner remaining amount TP. The toner usage amount is the amount of the used toner 9 of the toner 9 stored in the developing cartridge 200. The toner remaining amount TP is the amount of the remaining toner 9 among the toner 9 stored in the developing cartridge 200. The toner usage amount may be obtained by subtracting the toner remaining amount TP from the toner amount in the developing cartridge 200 before the start of use. The toner remaining amount TP may be obtained by subtracting the toner usage amount from the toner amount in the developing cartridge 200 before the start of use. The information regarding the usage amount of the developing cartridge 200 may be a value obtained by dividing the cumulative rotation speed or the cumulative rotation time of the developing roller 4 by the first predetermined value regarding the developing roller 4. The first predetermined value for the developing roller 4 is the number of rotations or the rotation time of the developing roller 4, and is a value set based on the life of the developing roller 4. The information regarding the usage amount of the developing cartridge 200 may be a value obtained by dividing the toner usage amount by the toner amount in the developing cartridge 200 before the start of use. The information regarding the usage amount of the developing cartridge 200 may be a value obtained by dividing the toner remaining amount TP by the toner amount in the developing cartridge 200 before the start of use. The CPU 501 can acquire information regarding the usage amount of the developing cartridge 200 based on the information held in the DT memory m2.
The CPU 501 may read the developing roller running distance correction coefficient k (third correction coefficient) according to the image forming mode. Specifically, the CPU 501 reads the developing roller running 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 traveling distance correction coefficient k read by the CPU 501 can be set to k=1 in the normal mode and k=1.5 in the high density mode. Further, the CPU 501 may read the developing roller travel distance correction coefficient k calculated by multiplying the correction coefficient k1 corresponding to the information regarding the usage amount of the developing cartridge 200 by the correction coefficient k2 corresponding to the image forming mode. The correction coefficients k1 and k2 are stored in the DT memory m2.
Then, the CPU 501, as the correction distance acquisition unit, multiplies the predetermined traveling distance Wu by the developing roller traveling distance correction coefficient k to calculate the corrected developing roller traveling distance Hu.
Hu=Wu×k

Next, the CPU 501 cumulatively adds the corrected developing roller running distance Hu to the cumulative developing roller running distance HT _n−1 from the start of use of the developing cartridge 200 stored in the DT memory m2. By doing so, the CPU 501 causes the total correction distance after development roller travel distance HT _n (n=1, 2,... N, HT ₀ =0), that is, the latest cumulative development roller travel distance HT. Calculate _n .
HT _n =HT _n-1 +Hu

Then, the CPU 501 uses the developing roller running distance threshold Wth _{1 in the} normal mode stored in the DT memory m2 and the latest cumulative developing roller running distance HT _n to calculate the remaining life DP1 of the developing roller in the normal mode according to the following formula. To calculate.
_{DP1 [%] = (1-} HT n / Wth 1) × 100
Further, the CPU 501 calculates the remaining life of the developing roller in the normal mode by the following formula from the developing roller running distance threshold value Wth _{2 in the} high density mode stored in the DT memory m2 and the latest accumulated developing roller running distance HT _n. Calculate DP2.
_{DP2 [%] = (1-} HT n / Wth 2) × 100
The developing roller traveling distance threshold Wth _{1 in the} normal mode (hereinafter, referred to as traveling distance threshold Wth ₁ ) is an example of a first life threshold regarding the life of the developing roller 4. The developing roller running distance threshold Wth _{2 in the} high density mode (hereinafter, referred to as running distance threshold Wth ₂ ) is an example of a second life threshold regarding the life of the developing roller 4.

Then, the latest accumulated developing roller traveling distance HT _n (life judgment value) is written and updated in the DT memory m2 as the accumulated developing roller traveling distance HT _n-1 for the next life judgment.
Here, when the remaining life of the developing roller DP1 or DP2=100%, it means that the developing cartridge 200 is new. Further, when the remaining life DP1 of the developing roller or DP2≦0%, it indicates that the developing cartridge 200 is the replacement timing.

In the present exemplary embodiment, the running distance threshold Wth ₁ in the normal mode is such that the toner coating amount on the developing roller 4 is not sufficiently regulated by the regulating member 8 and the toner fogging on the white background portion due to the poor regulation occurs in the normal mode. It was set based on the mileage. The traveling distance threshold Wth _{2 in} the high density mode is a developing roller that causes density unevenness due to banding due to slipping of the photosensitive drum 1 and the developing roller 4 when the peripheral speed ratio of the photosensitive drum 1 and the developing roller 4 is set to be large in a predetermined state. It was set based on the mileage. The predetermined state is a state in which a slight regulation defect occurs in the latter half of the life of the developing roller 4 even if the regulation defect is not such that toner fogging occurs on the white background portion.

Here, the relationship between the traveling distance of the developing roller, the defective regulation, and the banding will be described. The supply roller 5, the regulating member 8 and the surface of the photosensitive drum 1 are in contact with the developing roller 4, and a predetermined potential difference is generated between the developing roller 4 and the surface of the supplying roller 5, the regulating member 8 and the photosensitive drum 1. Is occurring. At this time, a current flows through the developing roller 4, and the resistance value of the developing roller 4 increases (deterioration of energization). When the resistance value of the developing roller 4 increases, the charge held by the toner 9 on the developing roller 4 becomes difficult to escape, and the charge amount of the toner 9 increases. When the adhesive force of the toner 9 to the developing roller 4 increases and the adhesive force of the toner 9 exceeds the restricting force of the restricting member 8, the restricting member 8 cannot sufficiently restrict the toner 9, resulting in defective regulation.
The energization deterioration depends on the magnitude of the current flowing through the developing roller 4. FIG. 5A is a graph showing the relationship between the rotational peripheral speed ratio between the developing roller 4 and the photosensitive drum 1 and the current value flowing from the photosensitive drum 1 to the developing roller 4. When the rotation peripheral speed ratio between the photosensitive drum 1 and the developing roller 4 changes, the current value flowing through the developing roller 4 increases as the rotation peripheral speed ratio increases, as shown in FIG. That is, the larger the rotational peripheral speed ratio, the more the deterioration of energization proceeds. If there are modes with different rotational peripheral speed ratios, it is necessary to correct them.

With reference to FIG. 5B, banding that occurs when the amount of toner on the developing roller 4 increases due to poor regulation in the latter half of the life of the developing roller 4 when the high density mode is set will be described. When the amount of toner on the developing roller 4 increases and the peripheral speed ratio between the developing roller 4 and the photosensitive drum 1 increases at the location indicated by the arrow G1 in FIG. The roller 4 cannot follow the rotation of the photosensitive drum 1. As a result, the developing roller 4 slips and uneven speed is generated in the developing roller 4, which causes unevenness in the amount of toner developed on the photosensitive drum 1 at the location indicated by the arrow G2 in FIG. 5B. As a result, as shown in FIG. 5C, density unevenness (banding) occurs on the entire surface of the image printed on the recording material 12. When there are modes such as the normal mode and the high density mode in which the peripheral speed ratios of the photosensitive drum 1 and the developing roller 4 are different, the timing at which the regulation failure occurs differs. Further, regarding the banding that occurs in the high density mode, the timing at which banding occurs becomes earlier as the peripheral speed ratio becomes larger. Therefore, it is necessary to set the developing roller travel distance threshold for each image forming mode. Further, the degree of progress of deterioration due to energization changes depending on the characteristics of the developing roller 4. Since the specifications of the developing roller 4 may change, it is preferable to store the developing roller running distance threshold in each image forming mode in the DT memory M2 mounted on the developing cartridge 200. However, the present invention is not limited to this, and may be stored in the memory of the image forming apparatus main body.

[Development cartridge life judgment sequence]
FIG. 6 is a sequence chart for determining the life of the developing cartridge 200 in the first embodiment. Based on the information in the DT memory m2 installed in the developing cartridge 200, the CPU 501 incorporated in the control unit 300 performs the processing shown in the flowchart of FIG. 6 as a control unit or a determination unit to determine the life of the developing cartridge 200. The user is informed of the determination result.

The flowchart shown in FIG. 6 will be described. First, the image forming apparatus 100 receives print data based on a document created by an external computer through the external I/F 504 (S501).
The CPU 501 selects the normal mode if, for example, “0” is set in the setting information included in the print data, and the high density mode if the setting information is set to “1”, and executes the subsequent processing. (S502).

Next, the CPU 501 starts the image forming operation of the image forming apparatus 100 including the developing cartridge 200 (S503). The image forming operation here includes the charging potential of the charging roller 2, the developing potential setting of the developing roller 4, the rotational driving of the photosensitive drum 1 and the developing roller 4 having a predetermined rotation peripheral speed ratio, etc., which are described in Table 1. , Including all operations required for image formation. It should be noted that when the driving of the developing roller 4 is started, the traveling distance Wu is measured by the CPU 501, and such measurement processing is also included in the image forming operation here. The traveling distance Wu measured when the normal mode is selected in S501 corresponds to the first drive amount information of the first mode, and the traveling distance Wu measured when the high-concentration mode is selected is the second. This corresponds to the second drive amount information of the mode.

Next, the CPU 501 reads the developing roller travel distance correction coefficient k from the DT memory m2 (S504). As described above, the CPU 501 reads the developing roller travel distance correction coefficient k according to the information regarding 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 CPU 501 reads the developing roller running distance correction coefficient k corresponding to the image forming mode, for example, k=1.5 when the image forming mode is the high density mode, or k=1 when the image forming mode is the normal mode. , CPU 501 reads. If the correction coefficient of the selected image forming mode is 1, it is not necessary to perform correction, and thus the processing of S102 may be skipped by the CPU 501.

Next, the CPU 501 calculates the corrected developing roller travel distance Hu using the read developing roller travel distance correction coefficient k (S505). The timing at which the CPU 501 calculates the corrected developing roller travel distance Hu may be after the printing is completed or at a predetermined interval. In either case, the calculation target is the uncalculated traveling distance Wu.

Then, the CPU 501 runs from the corrected developing roller running distance Hu and the previous cumulative developing roller running distance HT _n−1 stored in the DT memory m2 to the latest cumulative developing roller running as a life judgment value. The distance HT _n is calculated (S506).
Next, the CPU 501 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 CPU 501 reads the traveling distance threshold Wth ₁ in the normal mode from the DT memory M2 (S508). After that, the CPU 501 compares the latest accumulated developing roller traveling distance HT _n with the traveling distance threshold Wth ₁ in the normal mode, and the latest accumulated developing roller traveling distance HT _n is the traveling distance threshold Wt in the normal mode.
It is determined whether or not h ₁ is exceeded (S509). Then, CPU 501 may, if the latest cumulative after development roller running distance HT _n exceeds the mileage threshold Wth ₁ in the normal mode, writes the latest cumulative after development roller running distance HT _n the DT memory m2 (S511). After that, the notification means is used to notify the user that the developing cartridge 200 has reached the end of its life through the external I/F 504 (S512). The notification means may be a body display means such as a monitor, a voice speaker, or the like, but is not limited to these. For example, a message may be sent to an external device such as a PC connected to the image forming apparatus. Good.

In S509, the life of the developing roller 4 is determined using the travel distance threshold Wth ₁ in the normal mode stored in the DT memory m2, but the invention is not limited to this. The traveling distance threshold Wth _{2 in} the high density mode and the developing roller life threshold correction coefficient C1 in the normal mode may be stored in the DT memory m2. In S508, the CPU 501 reads the traveling distance threshold Wth ₂ in the high density mode and the developing roller life threshold correction coefficient C1 in the normal mode, and obtains the traveling distance threshold Wth _1-1 in the normal mode using the following formula. Good.
Wth _1-1 =Wth ₂ ×C1
Then, in S<b>509, the CPU 501 compares the latest post-accumulation developing roller travel distance HT _n with the travel distance threshold Wth _1-1 in the normal mode, and the latest post-accumulation development roller travel distance HT _n is the travel distance in the normal mode. It may be determined whether or not the threshold value Wth _1-1 is exceeded. The travel distance threshold Wth _{1-1 in the} normal mode is an example of a third lifetime threshold regarding the lifetime of the developing roller 4. The method for calculating the running distance threshold Wth _1-1 in the normal mode using the developing roller life threshold correction coefficient C1 in the normal mode is the same in FIGS. 7 to 9 described later.
Table 2 below shows the development roller life threshold value correction coefficient C1 of the travel distance threshold Wth ₂ and the normal mode of the high-concentration mode. However, the numerical values shown in Table 2 are examples, and the present invention is not limited to these numerical values.

In the above, the CPU 501 determines the life of the developing roller 4 based on whether or not the latest accumulated developing roller traveling distance HT _n exceeds the traveling distance threshold Wth ₁ in the normal mode, but the present invention is not limited to this. That is, in step S<b>509, the CPU 501 calculates the remaining life DP1 of the developing roller in the normal mode by using the following formula, and determines whether the remaining life DP1 of the developing roller in the normal mode is 0 or less than a predetermined value. May determine the life of the.
_{DP1 [%] = (1-} HT n / Wth 1) × 100
Further, the remaining life DP1 of the developing roller may be calculated using the traveling distance threshold Wth _1-1 in the normal mode. The method of using the residual life DP1 of the developing roller in the normal mode is the same in FIG. 8 described later.

In step S509, if the latest accumulated developing roller traveling distance HT _n does not exceed the traveling distance threshold Wth ₁ in the normal mode, the CPU 501 writes the latest accumulated developing roller traveling distance HT _n in the DT memory m2 and updates it. Yes (S510). Then, the image forming apparatus 100 prepares for the next image formation. When Wth _1-1 is used in S509 and S510, the CPU 501 performs the same process as when Wth ₁ is used.

When the image forming mode is the high density mode, the CPU 501 reads the traveling distance threshold Wth ₂ in the high density mode from the DT memory M2 (S513). Thereafter, CPU 501 is the latest cumulative after development roller running distance HT _n compared to the travel distance threshold Wth ₂ high density mode, the latest cumulative after development roller mileage HT _n mileage threshold Wth ₂ high density mode It is determined whether or not it has exceeded (S514). Then, CPU 501 may, if the latest cumulative after development roller running distance HT _n exceeds a mileage threshold Wth ₂ high density mode, writes the latest cumulative after development roller running distance HT _n the DT memory m @ 2 (S516) .. After that, the notification means is used to notify the user that the developing cartridge 200 has reached the end of its life through the external I/F 504 (S512). After performing the notification process of S512, the CPU 501 may allow or prohibit the image forming operation of the image forming apparatus 100 in the normal mode according to an instruction from the user. Further, after performing the notification process of S512, the CPU 501 may allow or prohibit the image forming operation of the image forming apparatus 100 in the normal mode regardless of the instruction from the user.

In the above, the life of the developing roller 4 is determined using the traveling distance threshold value Wth ₂ in the high density mode stored in the DT memory m2, but the invention is not limited to this. The traveling distance threshold Wth _{1 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 m2. In S513, the CPU 501 reads the running distance threshold Wth _{1 in the} normal mode and the developing roller life threshold correction coefficient C2 in the high density mode, and obtains the running distance threshold Wth _2-1 in the high density mode using the following formula. May be.
Wth _2-1 =Wth ₁ ×C2
Then, in S514, the CPU 501 compares the latest post-accumulation developing roller travel distance HT _n with the travel distance threshold Wth _2-1 in the high density mode, and the latest post-accumulation development roller travel distance HT _n is in the high density mode. It may be determined whether or not the traveling distance threshold Wth _2-1 is exceeded. The traveling distance threshold Wth _{2-1 in} the high density mode is an example of a fourth life threshold regarding the life of the developing roller 4. The method of calculating the running distance threshold Wth _2-1 in the high density mode using the development roller life threshold correction coefficient C2 in the high density mode is the same in FIGS. 7 to 9 described later.
Table 3 below shows the traveling distance threshold value Wth ₁ in the normal mode and the developing roller life threshold value correction coefficient C 2 in the high density mode. However, the numerical values shown in Table 3 are examples, and the present invention is not limited to these numerical values.

In the above, the CPU 501 determines the life of the developing roller 4 based on whether or not the latest accumulated developing roller traveling distance HT _n exceeds the traveling distance threshold Wth ₂ in the high density mode, but the present invention is not limited to this. That is, in S514, the CPU 501 determines the remaining life DP2 of the developing roller using the following calculation formula, and determines the life of the developing roller 4 depending on whether the remaining life DP2 of the developing roller is 0 or less than a predetermined value. Good.
_{DP2 [%] = (1-} HT n / Wth 2) × 100
Further, the remaining life DP2 of the developing roller may be calculated using the traveling distance threshold Wth _2-1 in the high density mode. The method of using the residual life DP2 of the developing roller in the high density mode is the same in FIG. 8 described later.

Further, the reference running distance threshold Wth _R , the 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 m2. The reference travel distance threshold Wth _R is an example of a reference life threshold regarding the life of the developing roller 4.
In step S508, the CPU 501 may read the reference traveling distance threshold Wth _R and the developing roller life threshold correction coefficient C1 in the normal mode, and calculate the traveling distance threshold Wth _1-2 in the normal mode using the following formula.
Wth _1-2 =Wth _R ×C1
Then, in S<b>509, the CPU 501 compares the latest post-accumulation developing roller travel distance HT _n with the travel mode threshold Wth _{1-2 in the} normal mode, and compares the latest post-accumulation development roller travel distance HT _n.
May exceed the travel distance threshold Wth _1-2 in the normal mode. The travel distance threshold value Wth _{1-2 in the} normal mode is an example of a third lifetime threshold value regarding the lifetime of the developing roller 4. The method of using the travel distance threshold Wth _1-2 in the normal mode is the same in FIGS. 7 to 9 described later.
In S513, the CPU 501 reads the reference traveling distance threshold Wth _R and the developing roller life threshold correction coefficient C2 in the high density mode, and calculates the traveling distance threshold Wth _2-2 in the high density mode using the following formula. Good.
Wth _2-2 =Wth _R ×C2
Then, in S514, the CPU 501 compares the latest post-accumulation developing roller travel distance HT _n with the travel distance threshold Wth _2-2 in the high density mode, and the latest post-accumulation development roller travel distance HT _n is in the high density mode. It may be determined whether or not the traveling distance threshold Wth _2-2 is exceeded. The traveling distance threshold Wth _{2-2 in} the high density mode is an example of a fourth life threshold regarding the life of the developing roller 4. The method of using the traveling distance threshold Wth _2-2 in the high concentration mode is the same in FIGS. 7 to 9 described later.

In S514, when the latest cumulative post-accumulation developing roller travel distance HT _n, which is the total corrected development roller travel distance, does not exceed the travel distance threshold Wth ₂ , the CPU 501 sets the latest cumulative post-accumulation developing roller travel distance HT _n to DT. The data is written in the memory m2 and updated (S515). Then, the image forming apparatus 100 prepares for the next image formation.

On the other hand, after the CPU 501 receives the image information based on the print data (S517), the video count measuring unit 305 measures the video count value VC to calculate the total video count value VCt (S518). After that, the CPU 501 calculates the toner remaining amount TP (S519), and determines whether or not the toner remaining amount is small, that is, whether the toner remaining amount TP is 0% or less (whether it is a predetermined threshold remaining amount or less). (S520). If the toner remaining amount TP reaches 0% or less, the CPU 501 writes the cumulative video count value VCr in the DT memory m2 (S522) and notifies the user that the developing cartridge 200 has reached the end of its life (S512). .. On the other hand, when the toner remaining amount TP has not reached 0% or less, the CPU 501 writes the cumulative video count value VCr in the DT memory m2 (S521). Then, the image forming apparatus 100 prepares for the next image formation.

The calculation of the toner remaining amount TP has been described as the method of determining whether or not the toner remaining amount is low, but the method is not limited to this. For example, since the total video count value VCt indicates the toner consumption amount itself, the CPU 501 determines whether or not the total video count value Vct exceeds a predetermined threshold value, and whether the toner remaining amount is low or not. May be judged. Further, although the toner remaining amount detecting method by the video counting method has been described as an example, the present invention is not limited to this. For example, a remaining amount detection method based on capacitance or a light transmission remaining amount detection method may be used, or may be used in combination with these. Specifically, when the remaining amount of toner acquired by the video count method is less than or equal to a predetermined remaining amount, either the electrostatic capacity method or the light transmission method may be used. That is, a more suitable remaining amount acquisition method may be selected according to the degree of the remaining amount of toner. The electrostatic capacity method uses an electrode whose electrostatic capacity that is detected according to a change in the state of the toner 9 inside the developer accommodating chamber is used (for example, a conductive member is attached to the inner wall of the accommodating chamber). This is a method of acquiring the amount of toner 9 based on the detected change in capacitance. This is a known method in the related art, and detailed description thereof will be omitted. Further, the light transmission method uses a light source for irradiating the interior of the developer accommodating chamber with light and a light receiving portion for receiving the light that has passed through the accommodating chamber, and uses the toner 9 based on the change in the light receiving state of the light receiving portion. Is how to get the amount of. This method is also a known method in the related art, and detailed description thereof will be omitted. The same applies to the flowcharts described below.

In the first embodiment that executes this series of flowcharts, the travel distance threshold Wt of the developing roller 4 is set.
Is set according to the image forming mode. By doing so, it becomes possible to properly determine the life of the developing cartridge 200 and notify the user. Further, the detection result of the remaining amount of toner is also used to detect that the amount of toner in the developing cartridge 200 is almost exhausted. As a result, not only the service life of the developing roller 4 due to deterioration due to energization but also the service life of the developing cartridge 200 due to the remaining amount of the toner 9 can be notified, and the service life of the developing cartridge 200 can be notified to the user more appropriately.

[First different development cartridge life judgment sequence]
In the description of FIG. 6, the corrected developing roller traveling distance Hu is cumulatively added to HT _n−1 corresponding to the previous total corrected developing roller traveling distance, and the latest accumulated developing roller traveling distance (total traveling distance) HT _{n is} calculated. The method of determining the life of the developing roller 4 by determining However, it is not limited to this. For example, the post-correction developing roller travel distance Hu is cumulatively reduced from the developing roller travelable distance TD (Total Distance) stored in the DT memory m2 as an initial value at the start of use of the developing cartridge 200. By doing so, the travelable distance HT′ _n as a life judgment value for judging the life of the developing roller 4 may be calculated. Note that HT ₀ matches the developing roller travelable distance TD as an initial value.
HT' _n =HT' _n-1 -Hu

Hereinafter, the development cartridge life determination sequence by the cumulative reduction processing of the CPU 501 will be described in detail with reference to the flowchart of FIG. First, since the processing of S601 to S605 of FIG. 7 is the same as the processing of S501 to S505 described in FIG. 6, detailed description thereof will be omitted. Next, the corrected developing roller traveling distance Hu is gradually reduced from the initial value (developing roller traveling distance TD) stored in the DT memory m2 or the previous traveling distance HT′ _n−1 to obtain the latest traveling distance. to calculate the HT _'n (S606). Incidentally, the traveling distance HT _'n of the latest is equivalent to the lifetime determination value.
Since the processing of S607 and S608 of FIG. 7 is the same as the processing of S507 and S508 described in FIG. 6, detailed description thereof will be omitted. Then, CPU 501 is 'compares _n with mileage threshold Wth ₁ in the normal mode, the latest DTE HT' latest DTE HT whether the _n falls below the mileage threshold Wth ₁ in the normal mode A judgment is made (S609). If the travelable distance HT' _n is below the travel distance threshold Wth ₁ in the normal mode as determined by the CPU 501 in S609, the CPU 501 writes the travelable distance HT' _n after cumulative reduction in the DT memory m2 (S611). ). After that, the notification means is used to notify the user that the developing cartridge 200 has reached the end of its life through the external I/F 504 (S612).

In step S609, the CPU 501 determines the life of the developing roller 4 based on whether or not the travelable distance HT' _n is below the travel distance threshold Wth ₁ in the normal mode, but the present invention is not limited to this. That is, in step S609, the CPU 501 obtains the developing roller remaining life DP1′ in the normal mode using the following formula, and determines whether the remaining developing roller life DP1′ in the normal mode is 0 or less than a predetermined value. The life of the roller 4 may be determined.
DP1′[%]=(HT′ _n /Wth ₁ )×100
The method of using the residual life DP1′ of the developing roller in the normal mode is the same in FIG. 9 described later.

At S609, the latest of distance-HT 'is _n, if it is not less than the mileage threshold Wth ₁ of the normal mode, CPU501, the latest of the travel distance HT' by writing _n in the DT memory m2, to update ( S610). Then, the image forming apparatus 100 prepares for the next image formation.

Since the processing of S613 in FIG. 7 is the same as the processing of S513 described in FIG. 6, detailed description will be omitted. Then, CPU 501 is 'compares _n with mileage threshold Wth ₂ high density mode, latest DTE HT' latest DTE HT or not _n falls below the mileage threshold Wth ₂ high density mode not It is determined (S614). If the travelable distance HT' _n is below the travel distance threshold Wth ₂ in the high concentration mode as determined by the CPU 501 in S614, the CPU 501 writes the travelable distance HT' _n after cumulative reduction in the DT memory m2 ( S616). After that, the notification means is used to notify the user that the developing cartridge 200 has reached the end of its life through the external I/F 504 (S612). After performing the notification process of S612, the CPU 501 may allow or prohibit the image forming operation of the image forming apparatus 100 in the normal mode according to an instruction from the user. Further, after performing the notification process of S612, the CPU 501 may allow or prohibit the image forming operation of the image forming apparatus 100 in the normal mode regardless of the instruction from the user.

At S614, the latest DTE HT 'is _n, if not below the mileage threshold Wth ₂ high density mode, CPU 501, the latest DTE HT' writes _n to DT memory m2, updates (S615). Then, the image forming apparatus 100 prepares for the next image formation. Other processes are the same as those in the flowchart shown in FIG. 6, and detailed description thereof will be omitted.
Note that in S614, the CPU 501 determines the life of the developing roller 4 based on whether or not the travelable distance HT′ _n is below the travel distance threshold Wth ₂ in the high density mode, but the present invention is not limited to this. That is, in S614, the CPU 501 obtains the developing roller remaining life DP2′ in the high density mode using the following formula, and determines whether the developing roller remaining life DP2′ in the high density mode is 0 or less than a predetermined value. The life of the developing roller 4 may be determined.
DP2′[%]=(HT′ _n /Wth ₂ )×100
The method using the residual life DP2′ of the developing roller in the high density mode is the same in FIG. 9 described later.

Note that the frequency with which the processes of S604 to S616 are executed is not limited to a particular frequency. For example, the processing of S604 to S616 may be performed on the traveling distance Wu measured by the CPU 501 as needed every one second. Alternatively, each time the print job is completed, the processes of S604 to S616 may be performed on the traveling distance Wu measured from the start of the print job. Furthermore, the processes of S604 to 616 may be performed each time a predetermined number of print jobs are completed. The same applies to the processing of S504 to S516 of FIG. 6 described above.

[Second development cartridge life judgment sequence]
In the above description of FIGS. 6 and 7, the CPU 501 updates the post-accumulation developing roller travel distance HT _n and the travelable distance HT′ _{n at} a predetermined frequency, and whether the developing cartridge 200 has reached the end of its life. It was explained to judge whether or not. However, the same effect can be obtained by another life judgment sequence.
For example, the total running distance Wt ₀ of the developing roller in the normal mode and the total running distance Wt ₁ of the developing roller in the high density mode are respectively stored, and the CPU 501 stores the developing cartridge 200 based on the stored Wt ₀ and Wt _1. May determine the life of the. In the suffix of Wt, "0" means the normal mode and "1" means the high density mode. Hereinafter, the form will be described in detail with reference to the flowchart of FIG.

First, since the processing of S701 to S703 of FIG. 8 is the same as the processing of S101 to S103 described in FIG. 6, detailed description thereof will be omitted. Next, the CPU 501 updates Wt ₀ or Wt ₁ based on the image forming mode selected in S702 and the traveling distance Wu measured in S703 (S704). For example, the selected image forming mode in S702, in the case of high concentration mode, a running distance Wu measured in S703, and added to the developing roller total distance Wt _1, CPU 301, the latest Wt ₀ and Wt _{Get 1} . Here, Wt ₀ is the first total value obtained by accumulating the first drive amount information that is the travel distance Wu measured in the normal mode, and Wt ₁ is the second drive amount information that is the travel distance Wu measured in the high concentration mode. Respectively corresponding to the second total value, which will be described below with this term.

Next, the CPU 501 reads the developing roller running distance correction coefficient k corresponding to the image forming mode from the DT memory m2 (S705). Then, CPU 501 is in the normal mode amended development roller running distance Hu ₀ and the high concentration modes of the amended development roller running distance Hu _1, calculated on the basis of the development roller running distance correction coefficient k read in step S705, respectively (S706) .. For example, when the developing roller traveling distance correction coefficient k for the normal mode is 1 and the developing roller traveling distance correction coefficient k for the high density mode is 1.5, the CPU 501 causes Hu ₀ =Wt ₀ ×1, Hu ₁ =Wt ₁ Hu ₀ and Hu ₁ are calculated as ×1.5.
Then, the CPU 501 uses the calculated Hu ₀ and Hu ₁ to calculate the total travel distance Ht by an arithmetic expression of Ht=Hu ₀ +Hu ₁ (S707). The processes of S708 and S709 of FIG. 8 are the same as the processes of S507 and S508 described with reference to FIG. 6, and thus detailed description thereof will be omitted. After that, the CPU 501 determines whether the calculated total travel distance Ht exceeds the travel distance threshold Wth ₁ in the normal mode (S710). In S711 and S712, the CPU 501 writes the first total value Wt ₀ and the second total value Wt ₁ updated in S704 into the DT memory m2.
The processing of S713 and S714 of FIG. 8 is the same as the processing of S512 and S513 described in FIG. 6, and thus detailed description thereof will be omitted. Next, the CPU 501 determines whether the calculated total travel distance Ht exceeds the travel distance threshold Wth ₂ in the high concentration mode (S715). In S716 and S717, the CPU 501 writes the first total value Wt ₀ and the second total value Wt ₁ updated in S704 into the DT memory m2. It should be noted that the processing of each of the other steps is as described with reference to FIG. 6, and thus detailed description thereof will be omitted.

[Third Alternative Development Cartridge Lifespan Determination Sequence]
Further, by modifying the flow chart described in FIG. 8, the first total value Wt ₀ and the second total value Wt _{1 in} the high density mode are subtracted from the developing roller travelable distance TD as an initial value to determine the life of the developing cartridge 200. You may judge. Hereinafter, the form will be described in detail with reference to the flowchart of FIG.
Since the processing of S801 to S806 of FIG. 9 is the same as the processing of S701 to S706 described in FIG. 8, detailed description thereof will be omitted. Next, the CPU 501 subtracts the first total value Wt ₀ and the second total value Wt ₁ from the developing roller travelable distance TD as an initial value to calculate the travelable distance Ht′ (S807).
_{Ht '= TD- (Hu 0 +} Hu 1)
The processes of S808 and S809 in FIG. 9 are the same as the processes of S507 and S508 described in FIG. 6, and thus detailed description thereof will be omitted.
Next, the CPU 501 determines whether the calculated travelable distance Ht′ is below the traveled distance threshold Wth ₁ in the normal mode (S810). In S811 and S812, the CPU 501 writes the first total value Wt ₀ and the second total value Wt ₁ updated in S804 to the DT memory m2.
The processes of S813 and S814 of FIG. 9 are the same as the processes of S512 and S513 described with reference to FIG. 6, and detailed description thereof will be omitted. Next, the CPU 501 determines whether the calculated travelable distance Ht′ is below the travel distance threshold Wth ₂ in the high concentration mode (S815). In S816 and S817, the CPU 501 writes the first total value Wt ₀ and the second total value Wt ₁ updated in S804 to the DT memory m2. It should be noted that the processing of each of the other steps is as described with reference to FIG. 6, and thus detailed description thereof will be omitted.

また、表４では、トナー残量ＴＰに応じて現像ローラ走行距離補正係数ｋを変える場合について説明したが、これに限るものではない。現像ローラ４の累積回転数、現像ローラ４の累積回転時間又はトナー使用量に応じて替えてもよいし、これらを組み合わせて用いてもよい。用いる現像ローラ４の劣化に寄与するパラメータの変化に応じて適正に現像ローラ走行距離補正係数ｋが決められるようにすればよい。 In the above-mentioned FIG. 6, for example, the CPU 501 corrects the traveling distance threshold value Wth1 (first life threshold value) in the normal mode and the traveling distance threshold value Wth2 (second life threshold value) in the high density mode after the total developing roller traveling distance after correction. Compared to HTn. Then, the CPU 501 determines the life of the developing cartridge 200 in each mode based on the comparison result. Further, for example, in the flowchart of FIG. 8, the CPU 501 compares each of the travel distance threshold Wth1 (first life threshold) in the normal mode and the travel distance threshold Wth2 (second life threshold) in the high concentration mode with the total travel distance Ht. .. Then, the CPU 501 determines the life of the developing cartridge 200 in each mode based on the comparison result. In each of the flowcharts, the traveling distance threshold value (lifetime threshold value) of each mode is used. However, it is not limited to this form.
For example, the life threshold value Wth may be set to one, the life threshold value may be read by the CPU 501 from the DT memory m2, and the total travel distance may be calculated and prepared for the normal mode and the high concentration mode. .. Hereinafter, a case where the CPU 501 reads out one set of traveling distance threshold values Wth from the DT memory m2 will be described.
First, the CPU 501 acquires the total developing roller travel distance HTn (first life judgment value), which is the calculation result of step S506. Then, the total developing roller traveling distance HTn' (second lifetime determining value) obtained by multiplying the total developing roller traveling distance HTn (first lifetime determining value) by the correction coefficient D1 is set as the high density total developing roller traveling distance. For example, if Wth=3000000 [mm], HTn=2500000 [mm], and D1=1.25, the high-concentration total developing roller travel distance HTn′=HTn×D1=2500000 [mm]×1.25=315000[ mm]. That is, when Wth<315,000 [mm], the CPU 501 determines that the developing cartridge 200 has reached the end of its life in the high density mode. Also in the case of the flowchart of FIG. 8, the same effect can be obtained by multiplying Ht calculated by the CPU 501 in step S707 by D1.
That is, the DT memory m2 stores the life threshold value Wth (traveling distance threshold value Wth). Then, the CPU 501 determines the first life judgment value in the normal mode (first mode) and the high density mode (second mode) from the developing roller running distance HTn as the life judgment value obtained by the cumulative addition process in S506 of FIG. ) The second life judgment value is obtained. The developing roller travel distance HTn itself may be used as the first life judgment value. Then, the CPU 501 compares the lifetime threshold value Wth stored in the DT memory m2 with the first lifetime determination value, and determines whether the latest first lifetime determination value exceeds the lifetime threshold value Wth. The CPU 501 also compares the second life judgment value with the life threshold Wth stored in the DT memory m2, and determines whether the latest second life judgment value exceeds the life threshold Wth. The various processes after the CPU 501 determines that each life judgment value exceeds the life threshold Wth are the same as those described above, and a detailed description thereof will be omitted here.
Further, in the case of the flowchart of FIG. 7, the travelable distance HT′n calculated in step S606 is set for the normal mode, and the CPU 501 calculates the travelable distance (HT′n)′ of high concentration based on that. More specifically, the correction coefficient may be E1, and the value obtained by subtracting E1 from the travelable distance HT'n may be taken as the high-concentration travelable distance (HT'n)'. In this case, the travel distance threshold value Wth (lifetime threshold value Wth) that is compared with the travelable distance is set to one.
For example, E1=600,000 [mm], travel distance threshold Wth (lifetime threshold)=0 [mm], and travelable distance HT'n (first travelable distance) calculated in step S606 is 500000 [mm]. In that case, the travelable distance (HT'n) (second travelable distance)' in the high concentration mode is (HT'n)'=500,000 [mm]-600000[mm]=-100,000<0 (life threshold. Wth), and the CPU 501 determines that the developing cartridge 200 has reached the end of its life in the high density mode. On the other hand, the travelable distance HT'n (500,000 [mm])>0 (lifetime threshold value Wth) is established, and the CPU 501 does not determine that the developing cartridge 200 has reached the end of life in the normal mode. The various processes after the CPU 501 determines that each life judgment value exceeds the life threshold are the same as those described above, and a detailed description thereof will be omitted here.
Further, also in the case of the flowchart of FIG. 9, the same effect can be obtained by subtracting E1 from the travelable distance Ht′ calculated by the CPU 501 in step S807.
That is, the DT memory m2 stores the life threshold value Wth (traveling distance threshold value Wth). Then, the CPU 501, based on the travelable distance Ht′n and the travelable distance Ht′ obtained in S606 of FIG. 7 and S807 of FIG. 9, corresponds to the first travelable distance (first life determination value) corresponding to the normal mode. ) Or a second travelable distance (second life judgment value) corresponding to the high concentration mode. The CPU 501 obtains the second travelable distance (second life determination value) by subtracting, for example, E1 from the first travelable distance (first life determination value). Further, 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. 7 or S807 of FIG.
Then, the CPU 501 compares each runnable distance with one set of runnable distance thresholds Wth (lifetime threshold Wth) stored in the DT memory m2, and each runnable distance (each life determination value) is the traveled distance threshold value. It is determined whether or not it has fallen below Wth. The travel distance threshold Wth can be set to Wth=0, for example. Note that the various processes after the CPU 501 determines that each life judgment value (each travelable distance) is below the life threshold Wth are the same as those described above, and a detailed description thereof is omitted here.
<Specific example>
In this embodiment, the developing roller running distance correction coefficient k is changed according to the toner remaining amount TP. That is, 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. Then, the CPU 501 can use the correction coefficient k for the developing roller traveling distance, which is divided according to the remaining toner amount TP. The plurality of correction coefficients are stored in, for example, the DT memory m2 and read by the CPU 501 as appropriate. The correction coefficients classified 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 there are three ways to classify the remaining toner amount TP in Table 4, the method is not limited to this. For example, it may be divided into five sections in more detail. Further, the correction coefficient may be calculated and used in a continuous image manner according to the magnitude of the toner remaining amount TP. The same classification can be performed by replacing the remaining toner amount TP with the cumulative toner usage amount.

Further, although Table 4 describes the case where the developing roller traveling distance correction coefficient k is changed according to the remaining toner amount TP, the present invention is not limited to this. It may be changed according to the cumulative number of rotations of the developing roller 4, the cumulative rotation time of the developing roller 4, or the amount of toner used, or these may be used in combination. It suffices that the developing roller travel distance correction coefficient k is appropriately determined according to the change in the parameter that contributes to the deterioration of the developing roller 4 used.

10A, 10B, and 10C show the image forming apparatus 100 by changing the printing area (printing rate: toner 9 consumption amount per sheet) printed on one recording material 12. FIG. 7 is a diagram showing a relationship between the remaining toner amount TP and the remaining life of the developing roller 4 when printing is performed using the same. In each figure, the vertical axis represents the remaining toner amount TP [%], and the horizontal axis represents the remaining life DP of the developing roller DP [%]. In each drawing, Zone1 is an area to which the developing roller travel distance correction coefficient k1 is applied, Zone2 is an area to which the developing roller travel distance correction coefficient k2 is applied, and Zone3 is the developing roller travel distance correction coefficient k3. The area is shown. When calculating the corrected developing roller travel distance Hu, which developing roller travel distance correction coefficient k is to be used is determined depending on which Zone the toner remaining amount TP is. Further, in each figure, the solid line shows the transition of the remaining life DP of the developing roller when the traveling distance of the developing roller 4 is corrected, and the broken line shows the transition of the remaining life DP of the developing roller when the traveling distance of the developing roller is not corrected. Is shown.

FIG. 10A shows a case where printing is performed at a constant printing rate of about 1%. In the case of FIG. 10A, since the solid line and the broken line are always present in Zone1, the developing roller running distance correction coefficient k1=1.0 is applied. Therefore, the remaining life DP of the developing roller indicated by the solid line and the remaining life DP of the developing roller indicated by the broken line do not overlap. Then, when the remaining life DP of the developing roller reaches 0% (point A1), the life of the developing cartridge 200 is notified.

FIG. 10B shows a case where printing is performed at a constant printing rate of about 1 to 2%. In the case of FIG. 10B, since the solid line and the broken line exist in Zone 1 until the remaining toner amount TP reaches 40%, the developing roller traveling distance correction coefficient k1=1.0 is applied. When the toner remaining amount TP is in the range of 40% to 21%, the solid line and the broken line are present in Zone2, and therefore the developing roller traveling distance correction coefficient k2=1.3 is applied. The slope of the solid line changes from point B1 (toner remaining amount TP=40%). That is, when the travel distance W of the developing roller 4 is corrected, the increase in the travel distance of the developing roller 4 becomes large when the remaining toner amount TP is in the range of 40% to 21%. When the running distance of the developing roller 4 is corrected, the remaining life DP of the developing roller reaches 0% at the time when the remaining toner amount TP reaches 20% (point A2), and the remaining life of the developing cartridge 200 is reduced. Notifications are made. On the other hand, the slope of the broken line has not changed. That is, when the travel distance of the developing roller 4 is not corrected, the increase in the travel distance of the developing roller 4 is constant regardless of the toner remaining amount TP.

FIG. 10C shows a case where printing is performed at a constant printing rate of about 7-8%. In the case of FIG. 10C, since the solid line and the broken line exist in Zone 1 until the remaining toner amount TP reaches 41%, the developing roller traveling distance correction coefficient k1=1.0 is applied. When the remaining toner amount TP becomes lower than 41%, the solid line and the broken line exist in Zone2, and therefore the developing roller running distance correction coefficient k2=1.3 is applied. When the remaining toner amount TP becomes lower than 21%, the solid line and the broken line exist in Zone3, and therefore the developing roller traveling distance correction coefficient k3=5.0 is applied. The slope of the solid line changes from point B6 (remaining toner amount TP=40%) and point B7 (remaining toner amount TP=20%). That is, when the travel distance of the developing roller 4 is corrected, the increase in the travel distance of the developing roller 4 is large and the remaining toner amount TP is 20% to 0 when the remaining toner amount TP is in the range of 40% to 21%. In the range of %, the increase in the traveling distance of the developing roller 4 becomes even larger. When the traveling distance of the developing roller 4 is corrected, the life of the developing cartridge 200 is notified when the remaining toner amount TP reaches 0% (point B8).

Here, a specific example of each case of FIG. 10(A), (B), and (C) is arranged. FIG. 11 shows a developing roller life line α obtained by connecting a point A1 in FIG. 10A, a point B2 in FIG. 10B, and a point B5 in FIG. 10C with a straight line. The developing roller life line α is a line indicating the life of the developing cartridge 200 when the traveling distance of the developing roller 4 is not corrected. As shown in FIG. 11, the remaining life of the developing roller 4 is short (the running distance of the developing roller 4 is long) and the remaining toner amount TP is small, that is, before the remaining life of the developing roller 4 reaches 0%. , The developing roller life line α is drawn. This is because when the running distance of the developing roller 4 is long and the remaining amount of the toner 9 is small, the adhesive force of the toner 9 to the developing roller 4 is high, and the regulation failure occurs in the area β in FIG. 11. Therefore, by correcting the traveling distance of the developing roller 4, the life of the developing cartridge 200 can be reached before the area β is reached.

通常モードの走行距離閾値Ｗｔｈ_１よりも高濃度モードの走行距離閾値Ｗｔｈ_２を低く設定する理由は、先述したように高濃度モードにおいて、バンディングによる濃度ムラが発生しやすいためである。 For example, the traveling distance threshold Wth ₁ in the normal mode and the traveling distance threshold Wth ₂ in the high concentration mode may be set to the values shown in Table 5.

The reason why the travel distance threshold Wth ₂ in the high density mode is set lower than the travel distance threshold Wth _{1 in the} normal mode is that density unevenness due to banding is likely to occur in the high density mode as described above.

FIG. 12 shows the timing at which the life of the developing cartridge 200 is notified in the normal mode and the high density mode. The developing roller life line α shown by the solid line in FIG. 12 is the life line in the normal mode, and defective regulation occurs in the region β. The developing roller life line Z (wavy line) indicated by the broken line in FIG. 12 is the life line in the high density mode, and density unevenness due to banding occurs in the regions γ and β. That is, the developing cartridge 200 can be used up to the developing roller life line α (solid line) in the normal mode, and can be used up to the developing roller life line Z (broken line) in the high density mode. Then, the life of the developing cartridge 200 is notified at an optimal timing according to the image forming mode.
As described above, by setting the respective traveling distance thresholds according to the image forming mode, it is possible to perform the life notification in accordance with the image defect timing that occurs in each mode, without causing the image adverse effect in each mode. The life of the developing cartridge 200 can be notified.
The cartridge configuration has been described separately for the developing cartridge 200 and the drum cartridge 210, but the present invention is not limited to this embodiment such as an AIO cartridge in which the developing cartridge 200 and the drum cartridge 210 are integrated.
Although the nonvolatile memory of the cartridge is provided with the function of storing the information about the life, the image forming apparatus 100 stores the information, and the present invention is not limited to this embodiment. As the image forming mode, the two modes of the normal mode and the high density mode have been described, but the image forming apparatus 100 is not limited to the present embodiment such as having a plurality of modes.

また、各モードの現像ローラ走行距離補正係数と、現像ローラ走行可能距離ＴＤとの関係についても同様である。

このように、各モードに対する現像ローラ走行距離補正係数及び走行距離閾値Ｗｔｈの組み合わせは様々な形態が想定されるが、何れでも同様の効果を得られる。即ち、現像ローラ４の同じ駆動量に対して、通常モードにおいて累加又は累減する駆動量情報の大きさを、高濃度モードにおける累加又は累減する駆動量情報の大きさよりも大きくし、寿命判断値を更新できる。 [Modification Example of Using Developing Roller Distance Correction Coefficient k]
In the description of FIGS. 6 to 9, the developing roller travel distance correction coefficient k in the normal mode is 1 and the developing roller travel distance correction coefficient k in the high density mode is 1.5, but the invention is not limited to this. A developing roller driving distance correction factor value for each mode, the normal running distance threshold Wth ₂ mileage threshold Wth1 and high concentration mode mode, if kept ratio relationship is another correction coefficient for each mode May be assigned. Hereinafter, an example is shown in Tables 6 and 7.

The same applies to the relationship between the developing roller travel distance correction coefficient in each mode and the developing roller travelable distance TD.

As described above, various combinations of the developing roller travel distance correction coefficient and the travel distance threshold Wth are assumed for each mode, but the same effect can be obtained in any combination. That is, for the same drive amount of the developing roller 4, the size of the drive amount information that is cumulatively added or reduced in the normal mode is made larger than the size of the drive amount information that is cumulatively added or reduced in the high density mode to determine the life. You can update the value.

As described above, when the developing roller travel distance correction coefficient k is 1, the reading of the correction coefficient by the CPU 501 may be skipped, but when a correction coefficient other than 1 is assigned. The CPU 501 needs to read the correction coefficient. That is, the CPU 501 uses the correction coefficient only for the traveling distance Wu measured in the normal mode or the high concentration mode, or the traveling distance Wu measured in each mode, depending on what correction coefficient is assigned to each mode. A correction coefficient is used for both. In the case of FIGS. 8 and 9, the correction coefficient is used only for the first total value Wt ₀ or the second total value Wt _1, or the first total value Wt ₀ and the second total value accumulated in each mode are added. The correction coefficient is used for both of the values Wt ₁ . As described above, in this embodiment, the life of the developing cartridge 200 can be appropriately determined by using various correction coefficients.

In this embodiment, the developing roller running distance correction coefficient k may be changed according to the remaining life DP of the developing roller. That is, as shown in Table 8, the developing roller running distance correction coefficient k is divided into a plurality of correction coefficients (k1 to k3) according to the range of the remaining life DP of the developing roller. Then, the CPU 501 can use the above-mentioned developing roller running distance correction coefficient k as a correction coefficient divided according to the remaining life DP of the developing roller. The plurality of correction coefficients are stored in, for example, the DT memory m2 and read by the CPU 501 as appropriate. Although there are three ways of classifying the remaining life DP of the developing roller in Table 8, it is not limited to this. For example, it may be divided into five sections in more detail. Further, the correction coefficient may be calculated and used in a continuous image manner in accordance with the magnitude of the remaining life DP of the developing roller. Further, even if the remaining life DP of the developing roller is replaced with the cumulative driving amount of the developing roller, the same classification can be performed.

Then, the correction coefficients classified according to the remaining life DP of the developing roller in Table 8 may be applied only to the normal mode or the high density mode, or may be applied to both modes. Further, although Table 8 describes the case where the developing roller running distance correction coefficient k is changed according to the remaining life DP of the developing roller, the present invention is not limited to this. The remaining life DP of the developing roller and the information regarding the usage amount of the developing cartridge 200 may be used together. It suffices that the developing roller travel distance correction coefficient k be appropriately determined according to the change in the parameter that contributes to the deterioration of the developing roller 4 used.

[Example 2]
In this embodiment, the correction coefficient is also stored in the O memory m1 installed in the drum cartridge 210, and the correction coefficient is determined together with the correction coefficient stored in the DT memory m2 installed in the developing cartridge 200. It is a thing. As shown in FIG. 13, depending on the combination of the remaining life of the drum cartridge 210 and the remaining life of the developing cartridge 200, the density unevenness due to banding in the high density mode differs. This is because when the remaining life of the drum cartridge 210 decreases, 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. That is, the slip of the developing roller 4 is suppressed, and the occurrence of speed unevenness on the photosensitive drum 1 is suppressed. That is, the life of the developing cartridge 200 in the high density mode changes according to the life of the drum cartridge 210. Therefore, in the O memory m1 mounted on the drum cartridge 210, as shown in Table 9, the correction coefficient (fourth correction coefficient) divided into plural according to the remaining life of the drum cartridge is stored. By determining the final developing roller running distance correction coefficient k together with the developing roller running distance correction coefficient described above, it is possible to notify the user of the life more accurately. Although there are three ways of classifying the remaining life of the drum cartridge in Table 9, the method is not limited to this. For example, it may be divided into five sections in more detail. Further, the correction coefficient may be calculated and used in a continuous image manner according to the magnitude of the value of the remaining life of the drum cartridge. Further, even if the remaining life of the drum cartridge is replaced with the cumulative drum cartridge drive amount, the same classification can be performed.
Further, in the present embodiment, the correction coefficient is stored in the O memory m1 mounted on the drum cartridge 210, but if it is a method that can correctly determine the relationship between the remaining life of the drum cartridge 210 and the correction coefficient, this is Not limited. For example, information indicating the relationship between the usage status of the drum cartridge 210 and the correction coefficient may be stored in the main body of the image forming apparatus so that the CPU 501 can recognize the usage status of the drum cartridge 210 from the O memory m1.

[Development roller life calculation sequence in this embodiment]
A sequence for calculating the developing roller traveling distance in this embodiment will be described. The description of the same parts as those in the first embodiment will be omitted. The remaining life of the drum cartridge is obtained from the rotational speed of the photosensitive drum 1, the film thickness of the carrier transfer layer of the photosensitive drum 1 in the initial state stored in the O memory m1, the scraping speed of the carrier transfer layer, and the like. It is calculated using the degree of wear. Using the tables of Table 4 and Table 9, the corrected developing roller traveling distance Hu is stored in the predetermined traveling distance Wu in the developing roller traveling distance correction coefficient kn stored in the DT memory m2 and in the O memory m1. It is obtained by multiplying the developing roller travel distance correction coefficient on. The same applies to the corrected developing roller traveling distances Hu ₀ and Hu ₁ described in FIGS. 8 and 9.
Hu=Wu×kn×on (n=1, 2, 3)
For example, when the remaining toner amount TP is 30% and the remaining life of the drum cartridge is 20%, the developing roller running distance correction coefficient k is k=k1×o3=1.3×0.85=1.105. .. In this way, when obtaining the corrected developing roller running distance Hu, the developing roller running distance correction coefficient kn corrected by the developing roller running distance correction coefficient on (developed roller running distance correction coefficient k after correction) may be used.
According to this embodiment, by setting the developing roller travel distance correction coefficient according to the remaining life of the drum cartridge, it is possible to perform the life notification at the timing when the image defect occurs. Therefore, the life of the developing cartridge 200 can be notified without causing any adverse effect on the image in each image forming mode.

[Example 3]
In this embodiment, the developing roller travel distance threshold value is stored in the O memory m1 mounted on the drum cartridge 210. The developing roller running distance threshold as shown in Table 10 is stored in the O memory m1 mounted on the drum cartridge 210, and the CPU 501 calculates the developing roller remaining life DP accordingly. As a result, more accurate life notification can be given to the user. For example, in O memory m1 of mounting the drum cartridge 210, as shown in Table 10, the travel distance threshold _{Wth 2, Wth 3, Wth 4} of high concentration mode is divided into a plurality in accordance with the remaining service life of the drum cartridge Store it. In Table 10, there are three ways to classify the remaining life of the drum cartridge, but the method is not limited to this. For example, it may be divided into five sections in more detail. Further, the threshold value may be calculated and used continuously according to the value of the remaining life of the drum cartridge. Further, even if the remaining life of the drum cartridge is replaced with the cumulative drum cartridge drive amount, the same classification can be performed.
Further, in the present embodiment, the developing roller running distance threshold is stored in the O memory m1 mounted on the drum cartridge 210, but a method that can correctly determine the relationship between the remaining life of the drum cartridge 210 and the developing roller running distance threshold. If so, it is not limited to this. For example, information indicating the relationship between the usage status of the drum cartridge 210 and the developing roller travel distance threshold value is stored on the image forming apparatus main body side so that the CPU 501 can recognize the usage status of the drum cartridge 210 from the O memory m1. Good.

[Development roller travel distance calculation sequence in this embodiment]
A sequence for calculating the running distance of the developing roller in this embodiment will be described. In addition, the description of the same parts as those of the first and second embodiments will be omitted.
For example, the CPU 501 determines the traveling distance threshold Wth _L (L=2, 3, 4) in the high density mode using the remaining life of the drum cartridge obtained in the second embodiment and the table of Table 10. The CPU 501 calculates the remaining life DP1 of the developing roller in the normal mode from the total corrected developing roller traveling distance HT _n and the running distance threshold Wth ₁ in the normal mode. Further, the CPU 501 calculates the remaining life DP2 of the developing roller in the high density mode from the total corrected developing roller travel distance HT _n and the high-density mode travel distance threshold Wth _{L.
DP1 [%] = (1-} HT n / Wth 1) × 100
_{DP2 [%] = (1-} HT n / Wth L) × 100 (L = 2,3,4)
For example, when the remaining life of the drum cartridge is 20%, the travel distance threshold Wth ₁ =3000000 in the normal mode and the travel distance threshold Wth _L =Wth ₄ =2700000 in the high density mode. Then, the remaining life DP1 of the developing roller in the normal mode and the remaining life DP1 of the developing roller in the high density mode are as follows.
DP1[%]=(1-HT _n /3000000)×100
_{DP2 [%] = (1-} HT n / 2700000) × 100
The same applies to the remaining life DP1' of the developing roller in the normal mode and the remaining life DP2' of the developing roller in the high density mode described with reference to FIG. That is, the CPU 501 calculates the residual life DP1′ of the developing roller in the normal mode from the travelable distance HT′ _n and the traveling distance threshold Wth ₁ in the normal mode. Further, the CPU 501 calculates the remaining life DP2′ of the developing roller in the high density mode from the running distance HT′ _n and the running distance threshold Wth _L in the high density mode.
DP1′[%]=(HT′ _n /Wth ₁ )×100
DP2′[%]=(HT′ _n /Wth _L )×100 (L=2, 3, 4)
As described above, by setting the developing roller travel distance thresholds according to the life of the drum cartridge, it is possible to perform the life notification at the timing when the image defect occurs. As a result, the life of the developing cartridge 200 can be notified in each image forming mode without causing an adverse effect on the image.

表１１に示すように、ドラムカートリッジの残寿命が少なくなるほど、高濃度モードの現像ローラ寿命閾値補正係数ｐｋに割り当てられた数値が大きくなる。本実施例ではドラムカートリッジ２１０に搭載のＯメモリｍ１内に、ドラムカートリッジの残寿命に応じた高濃度モードの現像ローラ寿命閾値補正係数ｐｋを格納している。しかし、ドラムカートリッジ２１０の残寿命と高濃度モードの現像ローラ寿命閾値補正係数ｐｋとの関係を正しく判断できる方法であれば、これに限定されない。例えば、画像形成装置本体側にドラムカートリッジ２１０の使用状況と高濃度モードの現像ローラ寿命閾値補正係数ｐｋとの関係を示す情報を格納し、ＣＰＵ５０１が、ドラムカートリッジ２１０の使用状況をＯメモリｍ１から認識できるようにしてもよい。 [Example 4]
In this embodiment, the development roller life threshold correction coefficient pk (k=2, 3, 4) in the high density mode is stored in the O memory m1 mounted on the drum cartridge 210.
The developing roller life threshold correction coefficient pk (fifth correction coefficient) in the high density mode according to the remaining life of the drum cartridge as shown in Table 11 is stored in the O memory m1 mounted on the drum cartridge 210. The remaining life DP of the developing roller is calculated accordingly. In Table 11, there are three ways to classify the remaining life of the drum cartridge, but the method is not limited to this. For example, it may be divided into five sections in more detail. Further, the threshold value may be calculated and used continuously according to the value of the remaining life of the drum cartridge. Further, even if the remaining life of the drum cartridge is replaced with the cumulative drum cartridge drive amount, the same classification can be performed.

As shown in Table 11, as the remaining life of the drum cartridge decreases, the numerical value assigned to the developing roller life threshold correction coefficient pk in the high density mode increases. In this embodiment, the high-density mode developing roller life threshold correction coefficient pk corresponding to the remaining life of the drum cartridge is stored in the O memory m1 mounted on the drum cartridge 210. However, the present invention is not limited to this as long as the relationship between the remaining life of the drum cartridge 210 and the development roller life threshold correction coefficient pk in the high density mode can be correctly determined. For example, the image forming apparatus main body stores information indicating the relationship between the usage status of the drum cartridge 210 and the development roller life threshold correction coefficient pk in the high density mode, and the CPU 501 stores the usage status of the drum cartridge 210 from the O memory m1. You may make it recognizable.

[Development roller travel distance determination sequence in this embodiment]
A sequence for determining the running distance of the developing roller in this embodiment will be described. The description of the same parts as those of the first to third embodiments will be omitted.
Using the remaining life of the drum cartridge and the table of Table 11, the CPU 501 determines the developing roller life threshold correction coefficient pk in the high density mode. Then, the CPU 501 determines the traveling distance threshold Wth _k in the high concentration mode using the following formula.
Wth _k =Wth ₁ ×pk (k=2, 3, 4)
The CPU 501 calculates the remaining life DP1 of the developing roller in the normal mode from the total corrected developing roller traveling distance HT _n and the running distance threshold Wth ₁ in the normal mode. Further, CPU 501 includes a post total correction developing roller mileage HT _n, and a mileage threshold Wthk high concentration mode, calculates the developing roller remaining life DP2 high concentration mode.
_{DP1 [%] = (1-} HT n / Wth 1) × 100
_{DP2 [%] = (1-} HT n / Wth k) × 100 (k = 2,3,4)
For example, when the remaining life of the drum cartridge is 20%, the running distance threshold Wth _{k in} the high density mode is 2700000 (Wth ₃ =3000000×0.9), and the remaining life DP1 of the developing roller in the normal mode and the high density mode is DP2 is as follows.
DP1[%]=(1-HT _n /3000000)×100
_{DP2 [%] = (1-} HT n / 2700000) × 100
Further, the same 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 in FIG. 8, and the calculation method is the same as that in the third embodiment.
As described above, by setting the developing roller life threshold correction coefficient in the high density mode according to the life of the drum cartridge, it is possible to perform the life notification in accordance with the image defect occurrence timing. Therefore, the life of the developing cartridge 200 can be notified without causing any adverse effect on the image in each image forming mode.

DESCRIPTION OF SYMBOLS 1... Photosensitive drum, 4... Developing roller, 100... Image forming apparatus, 300... Control part, 501... CPU, m1... O memory, m2... DT memory

Claims (13)

A rotatable image carrier,
A developing device having a developer carrier for supplying a developer to the image carrier to develop the electrostatic latent image on the image carrier,
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 first mode in which the developer bearing member has a larger peripheral speed ratio with respect to the image bearing member. An image forming apparatus having a second mode of rotating at a peripheral speed ratio of 2,
Storage means for storing a first life threshold value of the developing device corresponding to the first mode and a second life threshold value of the developing device corresponding to the second mode;
The development based on first drive amount information when the developer carrier operates in the first mode and second drive amount information when the developer carrier operates in the second mode. Control means for renewing the life judgment value by cumulatively adding or subtracting the driving amount information of the developer carrier with respect to the life judgment value of the device,
And a notification means,
The control means is
(I) based on the first life threshold and the life judgment value, or (ii) a third life threshold and the life judgment value calculated using one of the second life threshold and the reference life threshold. , A first judgment relating to the life of the first mode is performed,
(I) Based on the second life threshold and the life judgment value, or (ii) a fourth life threshold calculated using one of the first life threshold and the reference life threshold and the life judgment value. And a second judgment regarding the life of the second mode based on
The notifying means is
An image forming apparatus, wherein notification is performed based on a determination result by the control unit. The control means is
Comparing the life judgment value with the first life threshold value to judge whether the life judgment value exceeds or falls below the first life threshold value;
The image forming apparatus according to claim 1, wherein the life judgment value is compared with the second life threshold value to judge whether the life judgment value exceeds or falls below the second life threshold value. Further comprising a remaining amount acquisition unit for acquiring the amount of the developer contained in the developer container to be supplied to the developer carrier,
Even when the life judgment value does not exceed the first life threshold value or the second life threshold value, the control unit has reached the end of life of the developing device when the remaining amount of the developer is small. The image forming apparatus according to claim 2, wherein the image forming apparatus determines. A rotatable image carrier,
A developing device having a developer carrier for supplying a developer to the image carrier to develop the electrostatic latent image on the image carrier,
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 first mode in which the developer bearing member has a larger peripheral speed ratio with respect to the image bearing member. An image forming apparatus having a second mode of rotating at a peripheral speed ratio of 2,
Storage means for storing any one of a first life threshold of the developing device corresponding to the first mode, a second life threshold of the developing device corresponding to the second mode, and a reference life threshold;
Life judgment based on first drive amount information when the developer carrier operates in the first mode and second drive amount information when the developer carrier operates in the second mode Control means for calculating the value,
And a notification means,
The control means is
(I) Based on the first life threshold and the life judgment value, or (ii) a third life threshold and the life judgment value calculated using one of the second life threshold and the reference life threshold. And a first judgment regarding the life of the first mode based on
(I) Based on the second life threshold and the life judgment value, or (ii) a fourth life threshold calculated using one of the first life threshold and the reference life threshold and the life judgment value. And a second judgment regarding the life of the second mode based on
The notifying means is
An image forming apparatus, wherein notification is performed based on a determination result by the control unit. The control means is
Comparing the life judgment value with the first life threshold value or the third life threshold value, and judging whether the life judgment value exceeds or falls below the first life threshold value or the third life threshold value,
Comparing the life judgment value with the second life threshold or the fourth life threshold, and judging whether the life judgment value exceeds or falls below the second life threshold or the fourth life threshold. The image forming apparatus according to claim 4. Further comprising a remaining amount acquisition unit for acquiring the amount of the developer contained in the developer container to be supplied to the developer carrier,
Even when the control unit does not exceed the first life threshold value, the second life threshold value, the third life threshold value, or the fourth life threshold value, the remaining amount of the developer remains. The image forming apparatus according to claim 5, wherein, when the number is small, it is determined that the developing device has reached the end of its life. The image forming apparatus according to claim 1, wherein the control unit allows the execution of the first mode after the notification based on the determination result of the second determination. The storage means stores a first correction coefficient,
The control unit reads the first correction coefficient stored in the storage unit and uses the first correction coefficient for the first drive amount information and/or the second drive amount information so that the same drive of the developer carrier is performed. With respect to the amount, the size of the drive amount information that is cumulatively added or reduced by the second drive amount information is made larger than the size of the drive amount information that is cumulatively added or reduced by the first drive amount information, and the life is increased. The image forming apparatus according to claim 1, wherein the determination value is updated. The first correction coefficient is at least one of a second correction coefficient according to information on the usage amount of the developing device and a third correction coefficient according to a rotational peripheral speed ratio between the image carrier and the developer carrier. The image forming apparatus according to claim 8, further comprising: The storage means stores a fourth correction coefficient according to the remaining life of the developer carrying member,
10. The control unit uses the first correction coefficient corrected by the fourth correction coefficient for the first drive amount information and/or the second drive amount information. The image forming apparatus described. The second life threshold value is divided into a plurality of ranges according to the remaining life of the developer carrier,
The control means makes a second determination regarding the lifetime of the second mode based on the second lifetime threshold value divided into the plurality of ranges and the lifetime determination value. Item 11. The image forming apparatus according to any one of items 1 to 10. The storage means stores a fifth correction coefficient according to the remaining life of the developer carrier,
12. The control unit makes the second judgment based on the second life threshold value corrected by the fifth correction coefficient and the life judgment value. The image forming apparatus according to item 1. A rotatable image carrier,
A developing device having a developer carrier for supplying a developer to the image carrier to develop the electrostatic latent image on the image carrier,
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 first mode in which the developer bearing member has a larger peripheral speed ratio with respect to the image bearing member. An image forming apparatus having a second mode of rotating at a peripheral speed ratio of 2,
Storage means for storing a life threshold of the developing device;
Based on first drive amount information when the developer carrier operates in the first mode and second drive amount information when the developer carrier operates in the second mode, A first life judgment value corresponding to one mode and a control means for calculating a second life judgment value corresponding to the second mode;
And a notification means,
The control means is
Based on a comparison between the life threshold value and the first life judgment value, the notifying unit is notified of the life of the developing device in the first mode,
An image forming apparatus, characterized in that the informing unit is informed of the life of the developing device in the second mode based on a comparison between the life threshold value and the second life judgment value.

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