JP5587056B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus having elements of a developing process such as an electrostatic latent image carrier, a developing device, and a cleaner container, and these elements are unitized into a plurality of units and detachable from an image forming apparatus main body.

  Conventionally, a process cartridge is used as a unit detachable from the image forming apparatus main body. In the conventional process cartridge, each element of the developing process such as a photosensitive member (electrostatic latent image carrier), a developing device (developing device), a charger, a toner hopper, a cleaning unit, a cleaner container, etc. is integrated into one cartridge. It was unitized. By the way, the lifetime of each element unitized in one process cartridge may be long or short. The cost of each element may be high or low. As a result, the lifetime of the entire process cartridge must be set as the lifetime of the process cartridge in combination with the element having the shortest lifetime. Moreover, expensive parts and cheap parts have to be exchanged together, resulting in an excessive economic burden on the user.

In order to solve such a problem, a configuration in which the process cartridge is divided into two units has been proposed. The first unit is a drum unit in which a photoconductor, a charger, a cleaning unit, and a waste toner box are unitized. The second unit is a developing unit in which a developing device and a toner hopper are unitized. When the photosensitive member has reached the end of its life or when the cleaner container is full of waste toner (hereinafter referred to as full tank), only the first unit is replaced, and the toner in the toner hopper is exhausted. Only the unit can be replaced. Thereby, the user's economic burden can be reduced. For this reason, in order to determine the replacement timing of the first unit, waste toner life management in the first unit has become important.
In addition, the developing units (second units) of each color of Y (yellow), M (magenta), C (cyan), and Bk (black) are mounted on a rotating support member and sequentially switched, and the drum unit (first unit) is exposed. There is an image forming apparatus that forms an image on a body. This image forming apparatus is called a four-cycle color image forming apparatus. Even in this configuration, if many second units are exchanged and used continuously, the waste toner becomes full in the cleaner container of the first unit. Therefore, in order to replace the first unit at a timing immediately before the waste toner is full in the cleaner container, it is important to manage the life of the waste toner in the first unit.

  As a means for solving this problem, Patent Document 1 proposes a configuration in which waste toner life management is performed by providing a light transmission type waste toner full sensor in a waste toner storage portion in a cleaner container. However, providing an optical window for transmitting light in the cleaner container and providing an optical detection sensor in the image forming apparatus causes a cost increase. Therefore, in Patent Document 2, it is proposed to calculate the accumulated amount of waste toner from the consumed toner amount and the transfer efficiency. More specifically, the integrated toner consumption and transfer efficiency are calculated from the pixel count and the print ratio. According to this, the transition of the accumulated amount of the waste toner can be notified at any time without increasing the cost, and the user can grasp the accumulated amount of the waste toner accurately and sequentially.

Japanese Patent Laid-Open No. 07-084480 JP 2003-316224 A

  However, even when the technique of Patent Document 2 is adopted, when the life of the photoconductor in the first unit is extended, the waste toner life management becomes inaccurate, and the waste toner becomes full in the cleaner container. Occurred. In addition, when there are a plurality of types in the second unit, more specifically, when there are a plurality of nominal lifetimes, that is, when a developer and a toner hopper having different toner storage amounts are mounted, the waste toner lifetime management is performed. This resulted in inaccuracy and a problem that the cleaner container was filled with waste toner.

  An object of the present invention is to accurately calculate the life of a cleaner container that decreases as the cumulative removal developer increases in the cleaner container of the first unit.

In order to solve the above problems, an image forming apparatus according to the present invention provides:
An electrostatic latent image carrier;
A developing device having a developer carrying member disposed opposite to the electrostatic latent image carrying member, and developing the electrostatic latent image formed on the electrostatic latent image carrying member into a developer image;
A cleaner container containing the removed developer removed from the electrostatic latent image carrier after the developer image is transferred to the transfer body;
With
The electrostatic latent image carrier and the cleaner container are provided in a first unit, the developing device is provided in a second unit separate from the first unit, and the first unit and the second unit are devices. An image forming apparatus detachable from a main body,
In the image forming apparatus that calculates the amount of removed developer that is removed every image formation, and calculates the life of the cleaner container from the amount of cumulative removed developer that is accommodated in the cleaner container.
A first storage unit is provided in the second unit for storing the usage level of the developer carrier.
One of the parameters for calculating the amount of removed developer that is removed for each image formation includes the degree of use of the developer carrier stored in the first storage unit ,
The degree of use of the developer carrier and the fogging of the developer that changes depending on the degree of use and adheres to an area of the electrostatic latent image carrier that does not become an electrostatic latent image when developed by the developing device. A reference table with a predetermined relationship with the quantity is provided,
Calculating the amount of removed developer to be removed for each image formation based on the amount of fog derived by taking the degree of use of the developer carrier stored in the first storage unit into the reference table ; Features.

  According to the present invention, it is possible to accurately calculate the lifetime of the cleaner container that decreases as the cumulatively removed developer increases in the cleaner container of the first unit.

1 is a schematic sectional view of an image forming apparatus according to Embodiment 1 of the present invention. 1 is a schematic sectional view of a process cartridge according to a first embodiment. The figure which shows the relationship between the primary transfer efficiency and the retransfer residual rate and the developing roller rotation speed A flowchart showing a waste toner life calculation routine 1 according to the first embodiment. 7 is a flowchart illustrating a primary transfer residual toner amount calculation subroutine according to the first embodiment. 7 is a flowchart illustrating a retransfer toner amount calculation subroutine according to the first embodiment. Schematic sectional view of an image forming apparatus according to Embodiment 2 2 is a schematic cross-sectional view of two types of process cartridges according to Embodiment 2. FIG. Diagram showing the relationship between fog and developing roller speed 8 is a flowchart illustrating a waste toner life calculation routine 2 according to the second embodiment. Diagram showing the relationship between fog and developing roller speed 10 is a flowchart illustrating a waste toner life calculation routine 3 according to the third embodiment.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be exemplarily described in detail with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention only to those unless otherwise specified. .

<Example 1>
(Image forming device)
FIG. 1 is a schematic diagram of a schematic configuration of an image forming apparatus according to Embodiment 1 of the present invention. This image forming apparatus forms an image on a sheet-like recording material P as a recording medium based on an electric image signal input to a controller unit (control means: CPU) 100 from a host device 99 such as a personal computer or a facsimile.
This image forming apparatus has a rotating drum type electrophotographic photosensitive member (photosensitive drum: hereinafter referred to as drum) 1 as an electrostatic latent image carrier that carries an electrostatic latent image on its surface. The drum 1 is rotationally driven at a predetermined speed in the counterclockwise direction indicated by the arrow R1 around the drum axis.
The charging means 2 is a means for uniformly charging the surface of the drum 1, and in this embodiment, a contact charging roller is used. The exposure means 3 is a means for forming an electrostatic latent image on the surface of the drum 1, and a laser scanner unit is used in this embodiment. The exposure unit 3 outputs laser light modulated in accordance with image information of each color input from the host device 99 to the controller unit 100, and scans and exposes the charged surface of the drum 1 at the exposure site A via the reflection mirror 4. To do. Thereby, an electrostatic latent image is formed on the surface of the drum 1.
At this time, the image information of each color input to the controller unit 100 is arithmetically processed, for example, as a printing ratio on A4 size standard paper, or the output time of the laser light modulated corresponding to the image information is arithmetically processed. The method is called pixel count. In the image forming apparatus of the present embodiment, the controller unit 100 processes pixel counts in a method of arithmetically processing the laser light output time.
FIG. 2 is an enlarged schematic view of the developing device 5 located at the developing position C. FIG. The developing device 5 as a developing device has a toner storage container 21 as a developer storage chamber in which the toner T is stored. The developing device 5 has a developing roller 25 as a developer carrying member disposed to face the drum 1 in order to develop the electrostatic latent image formed on the drum 1 into a developer image. Further, it has a coating roller 24 as a developer supply member that contacts the developing roller 25 and supplies toner. In addition, a regulating blade 27 is provided as a developer layer thickness regulating member that regulates the toner layer on the developing roller 25.
The image forming apparatus of this embodiment includes a plurality of developing devices. In this embodiment, each of the first to fourth developing devices 5a, 5b, 5c, and 5d is a contact developing type reversal developing device using a negatively charged nonmagnetic toner as a developer. The first developing device 5 a stores Y (yellow) toner in the toner storage container 21. The second developing device 5 b stores M (magenta) toner in the toner storage container 21. The third developing device 5 c stores C (cyan) toner in the toner storage container 21. The fourth developing device 5 d stores Bk (black) toner in the toner storage container 21.
These developing devices are held in a rotary 50 as a developing device holder (conversion means). Each of these developing devices is a developing unit as one second unit, and can be attached to and detached from the image forming apparatus main body by a take-out means (not shown).
A non-volatile cartridge memory 52 is provided as a first storage unit at a predetermined position of each color developing unit, and can be read and written by the CPU 100 of the image forming apparatus main body. In the cartridge memory 52, information relating to the life of the developing unit, for example, the number of rotations of the developing roller, the toner usage amount as the calculation result of the pixel count, and the like are written.
The rotary 50 is indexed and rotated at 90 ° intervals in the clockwise direction of the arrow R2 by a driving means (a motor (not shown) or the like). As a result, the first to fourth developing devices 5a, 5b, 5c, and 5d are sequentially moved to the developing position C that faces the drum 1 in a predetermined manner, and the electrostatic latent image is transferred to the toner image at this position C. Develop as.
The pixel count described above calculates the image information part on the drum surface by integrating the output time of the laser beam. That is, it is possible to obtain information correlating with the toner usage amount of the developing device 5 (5a, 5b, 5c, 5d: development unit), which is provided when developing the electrostatic latent image as a toner image.
The transfer unit 6 is a unit that transfers the toner image formed on the surface of the drum 1 to the recording material P. In this embodiment, an intermediate transfer belt unit is used. The transfer means 6 has an endless intermediate transfer belt (hereinafter referred to as a belt) 61 made of a dielectric material and having flexibility as a primary transfer body. The toner image is transferred from the drum 1 to the belt 61 in order to superimpose the toner images developed by a plurality of developing devices. The primary transfer roller 62 is in pressure contact with the drum 1 with the belt 61 interposed therebetween.
The secondary transfer roller 66 can be moved by a swing mechanism (not shown) to an operation position that is in contact with the secondary transfer counter roller 64 with the belt 61 interposed therebetween and a non-operation position that is separated from the surface of the belt 61. . The secondary transfer roller 66 is normally held at the non-operating position and moves to the operating position at a predetermined control timing.
The belt cleaning means 67 can be moved to a working position where the cleaning member contacts the surface of the belt 61 by a swing mechanism (not shown) and a non-working position where the cleaning member is separated from the surface of the belt 61, and has a predetermined control. Move to the working position at the timing.
The drum cleaning unit 7 scrapes off the primary transfer residual toner from the drum surface after the primary transfer (after the developer image has been transferred) with a cleaning blade. In addition, a toner image transferred to the belt 61, which will be described later, is returned from the belt 61 to the drum 1 when passing again through a primary transfer nip B formed at the contact portion between the drum 1 and the belt 61. Scrape off the retransfer toner. Waste toner (removed developer) removed from the drum surface is accommodated in a cleaner container 71.
In this embodiment, the photosensitive drum 1, the charging unit 2, the drum cleaning unit 7, and the cleaner container 71 are integrated into a unit to form a drum unit as a first unit, which is detachable from the main body of the image forming apparatus. . The drum unit is a unit separate from the developing unit.
Also at a predetermined position of the drum unit, a non-volatile cartridge memory 72 is provided as a second storage unit and can be read and written by the CPU 100 of the image forming apparatus main body. In the cartridge memory 72, information relating to the life of the drum 1, for example, the number of rotations of the drum 1, the bias application time by the charging means 2, the calculation results thereof, and the like are written. Further, information on the life of the cleaner container 71 (hereinafter referred to as “waste toner life”), which decreases as the amount of waste toner stored in the cleaner container 71 increases, is written.

Next, the image forming process will be described. When the image forming start signal is input, the controller unit 100 drives a main motor (not shown). Thereby, the drum 1 is rotationally driven at a predetermined speed in the counterclockwise direction of the arrow R1. Further, the rotary rotation of the rotary 50 is performed so that the first developing device 5a is moved to the developing position C. Then, the driving force is transmitted to the first developing device 5a. The exposure unit 3 is also driven. The belt 61 is rotationally driven at a speed corresponding to the speed of the drum 1 in the clockwise direction of the arrow R3 (forward direction with respect to the drum rotation). The secondary transfer roller 66 and the belt cleaning unit 67 are moved to and held at a non-operating position apart from the belt 61.
As a result, the surface of the rotating drum 1 is uniformly charged to about −500 V by the charging means 2. Laser light modulated in accordance with the Y color component image signal of the full-color image is output from the exposure unit 3 to the charged drum 1 to scan and expose the drum surface. The exposed part has a surface potential of −100V. Thereby, an electrostatic latent image corresponding to the Y color component image is formed on the drum surface. The electrostatic latent image is developed as a Y color toner image (developer image) by the first developing device 5a located at the development position C. At this time, a predetermined developing bias of −300 V is applied to the developing roller 25.
In this embodiment, the electrostatic latent image is reversely developed using a negative toner having the same polarity as the charging polarity (negative polarity) of the drum 1. The Y color toner image is primarily transferred onto the surface of the belt 61 at the primary transfer nip B. A primary transfer bias +500 V is applied to the primary transfer roller 62. The drum surface after the primary transfer is cleaned by the drum cleaning means 7, and the waste toner is removed to the cleaner container 71.
When the primary transfer of the Y-color toner image to the belt 61 is completed, the rotary 50 is intermittently rotated 90 ° in the clockwise direction, and the second developing device 5b moves to the developing position C. Then, charging / exposure / development steps for forming an M-color toner image corresponding to the M-color component image of the full-color image on the drum 1 are executed. In the primary transfer nip portion B, the M color toner image is superimposed and primary transferred in a state of being aligned with the Y color toner image already transferred on the belt 61.
Further, when the primary transfer of the M color toner image to the belt 61 is completed, the rotary 50 is further intermittently rotated by 90 ° in the clockwise direction, and the third developing device 5c is moved to the developing position C this time. Then, charging / exposure / development steps for forming a C-color toner image corresponding to the C-color component image of the full-color image on the drum 1 are executed. In the primary transfer nip portion B, the C color toner image is superimposed and primary-transferred in a state of being aligned with the Y color + M color toner image already transferred onto the belt 61.
Finally, when the primary transfer of the C-color toner image to the belt 61 is completed, the rotary 50 is further rotated by 90 ° in the clockwise direction, and the fourth developing device 5d is moved to the developing position C this time. Then, charging, exposure, and development steps for forming a Bk color toner image corresponding to the Bk color component image of the full color image on the drum 1 are performed. In the primary transfer nip portion B, the Bk color toner image is superimposed and primary-transferred while being aligned with the Y color + M color + C color toner image already transferred onto the belt 61.
In this way, four color full-color unfixed toner images of Y color + M color + C color + Bk color are superimposed on the belt 61 to form a composite. Note that the color order of the respective color toner images formed on the drum 1 is not limited to the order of Y color → M color → C color → Bk color as in this embodiment, but is performed in an appropriate color order. be able to.
The action of the secondary transfer roller 66 coming into contact with the belt 61 before the leading edge of the four-color full-color unfixed toner image formed on the belt 61 reaches the position of the secondary transfer roller 66 by the movement of the belt 61. Move to position. Further, the belt cleaning means 67 is also moved to the operating position with respect to the belt 61.
On the other hand, a sheet-like recording material P as a recording medium is separated and fed from a recording material feeding unit (not shown) at a predetermined control timing. The recording material P is introduced into a secondary transfer nip portion D which is a contact portion between the secondary transfer roller 66 and the belt 61 at a predetermined control timing by a registration roller unit (not shown). A secondary transfer bias + 1500 V is applied to the secondary transfer roller 66. As a result, in the process in which the recording material P is nipped and conveyed through the secondary transfer nip portion D, the four-color superimposed toner images on the belt 61 are successively and collectively transferred onto the surface of the recording material P.
The recording material P is separated from the surface of the belt 61 and introduced into the fixing unit 15, and is heated and pressurized at the fixing nip portion of the fixing unit 15. As a result, each color toner image is fixed (melted mixed color) to the recording material P. Then, the recording material P exits the fixing unit 15 and is discharged as a full-color image formed product to a discharge unit (not shown).
The secondary transfer residual toner remaining on the surface of the belt 61 after the recording material P is separated is removed by the belt cleaning unit 67.
When one or a plurality of continuous image forming jobs are completed, the controller unit 100 places the image forming apparatus in a standby state and waits for the input of the next image formation start signal. That is, the driving of the drum 1, the exposure means 3, the belt 61, etc. is stopped. The secondary transfer roller 66 and the belt cleaning unit 67 are moved to the non-operation position.

(Waste toner life)
In this embodiment, there are two types of waste toners removed and stored in the cleaner container 71, that is, the primary transfer residual toner and the retransfer toner. By estimating the amount of these toners, the waste toner life (cleaner container 71) is estimated. Lifespan) can be estimated.

(Primary transfer residual toner)
The primary transfer residual toner will be described. The primary transfer residual toner is toner that remains on the drum 1 without being transferred to the belt 61 when the toner image is primarily transferred from the drum 1 to the belt 61. As the developing roller 25 rotates, the toner T is thinly coated on the developing roller 25 by the action of the application roller 24 and the regulating blade 27. In this process, the toner T is rubbed and its own charging performance is lowered. Along with this, the amount of poorly charged toner contained in the thin coat increases. That is, there is a correlation between the rotation speed of the developing roller 25 and the primary transfer efficiency. Specifically, the rotational speed of the developing roller 25 and the primary transfer efficiency have a relationship in which the primary transfer efficiency decreases as the rotational speed of the developing roller 25 increases. Here, the rotation speed of the developing roller 25 corresponds to the degree of use of the developer carrier of the present invention. The primary transfer efficiency is a ratio of the toner on the drum 1 transferred to the belt 61 when the toner image is transferred to the belt 61.

(Retransfer toner)
The retransfer toner will be described. The retransfer is a phenomenon in which the toner of the toner image transferred to the belt 61 is returned from the belt 61 to the drum 1 again. This retransfer phenomenon is caused by the fact that when the drum 1 during the formation of the other color image passes through the primary transfer nip portion B, the high resistance substances are rotated in contact with each other in a high voltage application state, and therefore, peeling discharge in accordance with the Paschen's law occurs. Is caused. As a result of the peeling discharge, the toner having negative chargeability is positively charged and electrostatically transferred to the drum 1. Here, in the developing device 5, the toner is thinly coated on the developing roller 25 by the action of the application roller 24 and the regulating blade 27 as the developing roller 25 rotates. In this process, the toner is rubbed and its own charging performance is lowered. Along with this, the proportion of positive chargeability increases due to peeling discharge. That is, there is a correlation between the number of rotations of the developing roller 25 and the retransfer residual rate. Specifically, the rotation speed of the developing roller 25 and the retransfer residual rate have a relationship that the retransfer residual rate decreases as the rotation speed of the developing roller 25 increases. Here, the rotation speed of the developing roller 25 corresponds to the degree of use of the developer carrier of the present invention. The retransfer residual rate is a ratio of the toner on the belt 61 remaining without being transferred to the drum 1 when another toner image is transferred onto the toner image transferred onto the belt 61.
Therefore, in this embodiment, the waste toner life is determined based on the primary transfer efficiency and the retransfer residual rate that change according to the rotation speed of the developing roller 25. In other words, the waste toner life which is one of the drum unit lifespans is added to the amount of waste toner which changes according to the number of rotations of the developing roller 25 written in the cartridge memory 52 which is the first storage unit provided in the developing unit. And decide. That is, the rotation speed of the developing roller 25 is included as one of the parameters of the waste toner life calculated for each image formation.
FIG. 3A shows the relationship between the rotation speed of the Y color developing roller and the primary transfer efficiency of the Y color toner when the Y color toner image is primarily transferred to the belt 61.
In FIG. 3B, when the M toner image formed on the drum 1 is primary-transferred at the primary transfer nip B, superimposed on the Y-color toner image already transferred on the belt 61, The relationship between the Y color developing roller rotation speed and the Y color toner retransfer residual rate is shown.
The developing roller 25 of this embodiment rotates 10 times per A4 size recording material. The number of rotations of the developing roller can be measured by integrating the driving time of the motor that drives the developing roller 25. Further, since the number of rotations of the developing roller per A4 size recording material is constant, it can be converted into the number of formed images.
The rotation speed of the developing roller is stored in the cartridge memory 52 of the developing unit. The cartridge memory 52 also stores information relating to the toner color stored in the developing device 5, and the image forming apparatus main body can recognize the toner color stored in each developing device held by the rotary 50.
The image forming apparatus main body is provided with a primary transfer efficiency reference table (first reference table) for each toner color with respect to the rotation speed of the developing roller. In this reference table, the relationship between the rotation speed of the developing roller and the primary transfer efficiency that changes according to the rotation speed of the developing roller is determined in advance. In addition, the primary transfer efficiency for each toner color can be calculated by having only one primary transfer efficiency reference table for the rotation speed of the developing roller and performing arithmetic processing from the coefficient for each toner color.
Further, the image forming apparatus main body is provided with a reference table (second reference table) of the retransfer residual rate with respect to the rotation speed of the developing roller for each toner color. In this reference table, the relationship between the developing roller rotation speed and the retransfer residual rate that changes in accordance with the developing roller rotation speed is determined in advance. In addition to this, it is also possible to calculate the residual retransfer rate for each toner color by having only one retransfer residual rate reference table with respect to the rotation speed of the developing roller and performing arithmetic processing from the coefficient for each toner color.
Here, in the main body of the image forming apparatus, the printing percentage exposed by the laser beam is calculated by pixel count for each image forming sheet. At the same time, a value obtained by subtracting the exposed printing percentage from the number of pixels per A4 size recording material, that is, the non-printing percentage not exposed is calculated.

(Waste toner life calculation method)
A method for calculating the waste toner life will be described. For example, the printing percentage of Y color is XY%, the printing percentage of M color is XM%, the printing percentage of C color is XC%, and the printing percentage of Bk color is XBk%.
First, the rotation speed of the Y developing roller is read from the cartridge memory 52. The first developing device 5a develops the Y color toner image corresponding to the Y color component image of the full color image. The Y color toner image is primarily transferred at the primary transfer nip B. The primary transfer efficiency W at this time is read from the reference table of the image forming apparatus main body shown in FIG. 3A with respect to the developing roller rotation time read from the cartridge memory 52. Then, a value obtained by multiplying the Y color print% by (100−W) Y%, XY% × (100−W) Y%, is calculated as the primary transfer residual toner amount.
Next, the second developing device 5b develops the M color toner image corresponding to the M color component image of the full color image. The M color toner image is primarily transferred at the primary transfer nip B. Similarly to the Y color, XM% × (100−W) M% is calculated as the primary transfer residual toner amount.
At the same time, Y-color retransfer occurs. The color information and the developing roller rotation speed of the developing device 5 a that accommodates the Y color are read from the cartridge memory 52. The image forming apparatus main body derives the retransfer residual rate from the reference table of the retransfer residual rate Z with respect to the rotation speed of the developing roller corresponding to the toner color shown in FIG. 3B, and XY% × WY% × (100−Z ) Y% is calculated as the retransfer toner amount. That is, the amount of toner on the Y-color belt 61 is XY% × WY%, and if this is multiplied by the retransfer residual rate, it can be estimated as the retransfer toner amount at this time.
Further, in the primary transfer for forming the C color toner image, similarly, XC% × (100−W) C% is the primary transfer residual toner amount. At this time, the Y retransfer toner amount is XY% × WY% × ZY% × (100−Z) Y%, and the M retransfer amount is XM% × WM% × (100−Z) M%. It is.
Finally, charging / exposure / development steps for forming a Bk color toner image are performed. When the Bk color toner image is primarily transferred, XBk% × (100−W) Bk% is the primary transfer residual toner amount. The Y-color retransfer toner amount is XY% × WY% × ZY% × ZY% × (100−Z) Y%, and the M-color retransfer amount is XM% × WM% × ZM% × (100 -Z) The retransfer amount of M% and C color is XC% x WC% x (100-Z) C%.
Bk, which is the final image forming color, does not retransfer due to the apparatus configuration.

In summary, the Y color that is the first image forming color is a waste toner that is obtained by adding the following primary transfer residual toner amount and retransfer toner amount.
Primary transfer residual toner amount: XY% × (100−W) Y%
Retransfer toner amount: XY% × WY% × (100−Z) Y% + XY% × WY% × ZY% × (100−Z) Y% + XY% × WY% × ZY% × ZY% × (100−Z Y%
The M color which is the second image forming color is a waste toner obtained by adding the following primary transfer residual toner amount and retransfer toner amount.
Primary transfer residual toner amount: XM% × (100-W) M%
Retransfer toner amount: XM% × WM% × (100−Z) M% + XM% × WM% × ZM% × (100−Z) M%
The C color, which is the third image forming color, is a waste toner obtained by adding the following primary transfer residual toner amount and retransfer toner amount.
Primary transfer residual toner amount: XC% × (100-W) C%
Retransfer toner amount: XC% × WC% × (100-Z) C%
For the Bk color as the fourth image forming color, only the following primary transfer residual toner amount becomes waste toner.
Primary transfer residual toner amount: XBk% × (100-W) Bk%

  The amount of Y, M, C, and Bk waste toner calculated during the image forming operation this time is determined from the amount of toner that can be stored in the cleaner container 71 (capacity of the cleaner container 71), Subtracted with cumulative removed developer amount). This can be used as a subtraction counter, or can be shown as a percentage with respect to the cleaner container 71, for example, the remaining amount of remaining toner life. When the waste toner life is reached, the user can be notified that the life of the drum unit has expired or that the drum unit should be replaced. In addition, when the waste toner life reaches a predetermined threshold, for example, the remaining life of the drum unit can be notified to the user as a notice. In addition, as the life factor of the drum unit, it is also possible to notify the respective life for a plurality of factors.

(Waste toner life calculation routine 1)
A waste toner life calculation routine 1 for executing the above waste toner life calculation method is shown as a flowchart in FIG. FIG. 4 is a diagram illustrating a waste toner life calculation routine 1 according to the present embodiment.
When the waste toner life calculation routine 1 shown in FIG. 4 is executed, first, in S101, a Y-color image forming operation is performed.
In S102, a primary transfer residual toner amount calculation subroutine for the Y color image forming operation is called. FIG. 5 is a diagram illustrating a primary transfer residual toner amount calculation subroutine. When the primary transfer residual toner amount calculation subroutine during the Y color image forming operation is executed, in step S201, the print portion% (XY%) is calculated from the pixel count. In S202, the color information indicating that the color is Y is read from the cartridge memory 52 of the Y color development unit. In S203, a reference table for the primary transfer efficiency of the corresponding Y color is selected from the read Y color information. In S204, the developing roller rotation speed is read from the cartridge memory 52 of the Y developing unit. In S205, the developing roller rotation speed read in S204 is taken into the reference table shown in FIG. 3A selected in S203, and the primary transfer efficiency W% is derived. In S206, the primary transfer residual toner amount by the Y-color image forming operation is obtained by multiplying the printing portion% (XY%) by the primary transfer residual ratio (100-W) Y% remaining on the drum 1 by the primary transfer efficiency W%. XY% × (100−W) Y% is calculated.
In S103, an M color image forming operation is performed.
In S104, the primary transfer residual toner amount calculation subroutine shown in FIG. 5 during the M color image forming operation is called to calculate the primary transfer residual toner amount during the M color image forming operation. Processing similar to S102 is performed, and a primary transfer residual toner amount XM% × (100−W) M% by the M color image forming operation is calculated.
In S105, a retransfer toner amount calculation subroutine for the M color image forming operation is called. FIG. 6 is a diagram illustrating a retransfer toner amount calculation subroutine. When the retransfer toner amount calculation subroutine at the time of the M color image forming operation is executed, the Y color print portion% (XY%) is calculated from the pixel count in S301. In S302, the color information indicating that the color is Y is read from the cartridge memory 52 of the Y color development unit. In step S303, a reference table for the corresponding Y color retransfer residual rate is selected from the read Y color information. In S304, the developing roller rotation speed is read from the cartridge memory 52 of the Y developing unit. In S305, the developing roller rotation speed read in S304 is taken into the reference table shown in FIG. 3B selected in S303 to derive the retransfer residual rate Z%. In S306, the printing portion% (XY%) is multiplied by the primary transfer efficiency WY% and the actual retransfer rate (100-Z) Y% retransferred from the belt 61 to the drum 1 by the retransfer residual rate Z%. Then, the retransfer toner amount XY% × WY% × (100−Z) Y% by the M color image forming operation is calculated.
In S106, a C color image forming operation is performed.
In S107, the primary transfer residual toner amount calculation subroutine shown in FIG. 5 during the C color image forming operation is called to calculate the primary transfer residual toner amount in C color. Processing similar to S102 is performed, and a primary transfer residual toner amount XC% × (100−W) C% by the C-color image forming operation is calculated.
In S108, the retransfer toner amount calculation subroutine shown in FIG. 6 during the C color image forming operation is called to calculate the Y retransfer toner amount during the C color image forming operation. A process similar to S105 is performed on the Y color toner image. Since the amount of Y-color toner carried on the belt 61 is XY% × WY% × ZY%, this is multiplied by the actual retransfer rate (100−Z) Y% to obtain Y by the C-color image forming operation. The amount of color retransfer toner can be calculated as XY% × WY% × ZY% × (100−Z) Y%.
In S109, a retransfer toner amount calculation subroutine shown in FIG. 6 during the C color image forming operation is called to calculate the M retransfer toner amount during the C color image forming operation. Processing similar to S105 is performed for the M color toner image. The amount of M retransfer toner can be calculated in the same manner as the amount of Y retransfer toner in S105.
Thus, the retransfer toner amount XY% × WY% × ZY% × (100−Z) Y% + XM% × WM% × (100−Z) M% by the C color image forming operation is calculated.
In S110, a Bk color image forming operation is performed.
In S111, a primary transfer residual toner amount subroutine shown in FIG. 5 during the Bk color image forming operation is called to calculate the primary transfer residual toner amount in Bk color. The same processing as S102 is performed, and a primary transfer residual toner amount XBk% × (100−W) Bk% by the Bk color image forming operation is calculated.
In S112, the retransfer toner amount calculation subroutine shown in FIG. 6 during the Bk color image forming operation is called to calculate the Y retransfer toner amount during the Bk color image forming operation. A process similar to S105 is performed on the Y color toner image. The amount of Y-color toner carried on the belt 61 is XY% × WY% × ZY% × ZY%. Therefore, this is multiplied by the actual retransfer rate (100−Z) Y%, and the Y retransfer toner amount in the Bk color image forming operation is XY% × WY% × ZY% × ZY% × ( 100-Z) Y%.
In S113, the retransfer toner amount calculation subroutine shown in FIG. 6 during the Bk color image forming operation is called to calculate the M retransfer toner amount during the Bk color image forming operation. Processing similar to S105 is performed for the M color toner image. Since the amount of M color toner carried on the belt 61 is XM% × WM% × ZM%, this is multiplied by the actual retransfer rate (100−Z) M%, and M by the Bk color image forming operation is obtained. The amount of color retransfer toner can be calculated as XM% × WM% × ZM% × (100−Z) M%.
In S114, the retransfer toner amount calculation subroutine shown in FIG. 6 during the Bk color image forming operation is called to calculate the C retransfer toner amount during the Bk color image forming operation. A process similar to S105 is performed on the C-color toner image. The amount of C retransfer toner can be calculated in the same manner as the amount of C retransfer toner in S105.
Thus, the amount of retransfer toner XY% × WY% × ZY% × ZY% × (100−Z) Y% + XM% × WM% × ZM% × (100−Z) M% + XC% due to the Bk color image forming operation. * WC% * (100-Z) C% is calculated.
In S115, the sum of the primary transfer residual toner amount calculated in S102, S104, and S107 and the retransfer toner amount calculated in S105, S108, S109, S112, S113, and S114 are taken, and the waste toner due to the current image forming operation is obtained. Calculate the amount.
In S116, the waste toner life is calculated by subtracting the waste toner amount of the current image forming operation calculated in S115 from the capacity of the cleaner container 7 and the accumulated waste toner amount up to the previous time.
In S117, the developing roller rotation speed of the cartridge memory 52 of each developing unit is updated.
In S118, the waste toner life in the cartridge memory of the drum unit is updated to the waste toner life calculated in S116.
In step S119, it is determined whether the waste toner life updated in step S118 has reached a threshold for exhausting the life. If a positive determination is made in S119, the process proceeds to S120. If a negative determination is made in S119, this routine is once terminated.
In S120, the user is notified that the life of the drum cartridge has expired.

  In the present embodiment described above, the waste toner lifetime calculation method in the configuration in which the plurality of developing units as the second units act on the drum unit as the first unit has been described. In particular, in this embodiment, it is possible to accurately calculate the waste toner life of the first unit in consideration of the rotation speed of the developing roller stored in the cartridge memory 52 of the second unit. For this reason, even if the first unit and the second unit can be separately attached to and detached from the image forming apparatus main body, the waste toner life of the first unit can be accurately calculated.

<Example 2>
(Image forming device)
Next, Example 2 will be described. FIG. 7 is a diagram illustrating a schematic configuration of the image forming apparatus according to the present embodiment. The image forming apparatus 200 is mounted with a process cartridge composed of a first unit and a second unit. The first unit of the process cartridge is a drum unit 209 in which a photosensitive drum 205, a charging roller 206, a cleaning blade 207, and a cleaner container 208 are unitized. The second unit of the process cartridge is a developing unit 210 in which a developing device that develops the electrostatic latent image on the photosensitive drum 205 and the toner container 204 are unitized. The photosensitive drum 205 corresponds to the electrostatic latent image carrier of the present invention.
The drum unit 209 and the developing unit 210 are connected to each other at a place where the photosensitive drum 205 of the drum unit 209 and the developing device of the developing unit 210 face each other to form an integral process cartridge. Therefore, the drum unit 209 and the developing unit 210 are integrated with each other in the form of a process cartridge and can be detached from the image forming apparatus main body. However, the drum unit 209, which is the first unit, or the development unit 210, which is the second unit, can be detached from the image forming apparatus main body.
The developing device in the developing unit 210 includes a developing roller 201 as a developer carrier, a supply roller 202 as a developer supply member, and a regulating blade 203 as a developer regulating member. The developing roller 201 develops the electrostatic latent image formed on the photosensitive drum 205 into a toner image (developer image) using toner T which is a non-magnetic one-component developer as a developer. The supply roller 202 rotates in contact with the developing roller 201 and supplies the toner T to the developing roller 201. The regulating blade 203 abuts on the developing roller 201 and regulates the toner T supplied to the developing roller 201 into a thin layer. As the developing roller 201 is driven to rotate, the toner T is charged and thinly coated on the developing roller 201 by the action of the supply roller 202 and the regulating blade 203.
The developing unit 210 includes a toner storage container 204 that stores the toner T. In this embodiment, the toner container 204 is provided with toner remaining amount detecting means (not shown) for measuring the remaining amount of toner, and detects the amount of toner in the toner container 204. As a detection method, either a capacitance detection method or an optical detection method can be applied, and reports that the user has little toner remaining in a predetermined toner remaining amount, or prompts the developer unit 210 to be replaced. .
As will be described later, the developing unit 210 shown in FIG. 8 includes a plurality of types of developing units in which the shape of the toner storage container 204 and the amount of toner stored therein are different. In this embodiment, there are development units of A type (FIG. 8B) capable of forming 1000 sheets of images at a standard 5% printing rate and X type (FIG. 8A) capable of forming 2000 sheets of images. Any of them can be attached to and detached from the drum unit 209 and the image forming apparatus main body.
A non-volatile cartridge memory 211 is provided as a first storage unit at a predetermined position of the developing unit 210 and can be read and written by the CPU of the main body of the image forming apparatus. In the cartridge memory 211, information relating to the life of the developing unit 210, for example, the number of rotations of the developing roller, the amount of toner used as the calculation result of the pixel count, the detection result of the toner remaining amount detecting means, and the like are written. Since the pixel count has the same form as that of the first embodiment, the description thereof is omitted. In the cartridge memory 211, information on the type of the developing unit 210 and information on the type, for example, nominal life, toner storage amount, and the like are written.
Also at a predetermined position of the drum unit 209, a non-volatile cartridge memory 212 is provided as a second storage unit and can be read and written by the CPU of the image forming apparatus main body. In the cartridge memory 212, information relating to the life of the photosensitive drum 205, for example, the rotational speed of the photosensitive drum, the bias application time by the charging roller 206, and the calculation results thereof are written. In addition, information on the waste toner life (life of the cleaner container 208) is written.

  Next, the image forming process will be described. The photosensitive drum 205 rotates in the direction of arrow A. First, the photosensitive drum 205 is uniformly negatively charged by a charging roller 206 as charging means. Then, it exposes with the laser beam from the laser optical apparatus 213 which is an exposure means, and an electrostatic latent image is formed in the surface. This electrostatic latent image is developed by the developing unit 210 and visualized as a toner image. In this embodiment, the toner adheres to the exposed portion of the photosensitive drum 205 and is reversely developed. The visualized toner image on the photosensitive drum 205 is transferred to a recording material 215 as a transfer member by a transfer roller 214. Untransferred toner remaining on the photosensitive drum 205 without being transferred is scraped off by a cleaning blade 207 as a cleaning member and removed to the cleaner container 208. The cleaned photosensitive drum 205 repeats the above-described operation to form an image. On the other hand, the recording material 215 onto which the toner image has been transferred is permanently fixed by the fixing device 217 and then discharged outside the apparatus.

(Waste toner life)
In the present embodiment, there are two types of toners that are removed and collected in the cleaner container 208, that is, untransferred toner and fog toner, and by estimating the amount of these toners, the life of the waste toner can be estimated.

(Transfer residual toner)
The transfer residual toner will be described. The untransferred toner is a toner remaining on the photosensitive drum 205 without being transferred to the recording material 215 at a constant ratio with respect to the toner amount of the toner image obtained by visualizing the electrostatic latent image formed on the photosensitive drum 205. It is. In this embodiment, the ratio of the residual toner amount is 10% of the transferred toner amount.

(Cabritoner)
The fog toner will be described. The fog toner is poorly charged toner that adheres from the developing roller 201 to an area that does not form an electrostatic latent image on the photosensitive drum 205. In this embodiment, the fog toner amount is determined to be a predetermined amount per 1% of the fog amount that changes according to the rotation speed of the developing roller. As the developing roller 201 rotates, the toner T is thinly coated on the developing roller 201 by the action of the supply roller 202 and the regulating blade 203. In this process, the toner T is rubbed and its own charging performance is lowered. Along with this, the amount of poorly charged toner contained in the thin coat increases. That is, there is a correlation between the rotation speed of the developing roller 201 and the fog toner amount. Specifically, the rotational speed of the developing roller 201 and the fog toner amount have a relationship in which the fog amount increases and the fog toner amount increases as the rotational speed of the developing roller 201 increases. Here, the rotation speed of the developing roller 201 corresponds to the degree of use of the developer carrier of the present invention.
Further, according to the amount of toner stored in the toner storage container 204, the probability that the toner moves to the vicinity of the developing roller 201 and is rubbed by the action of the supply roller 202 and the regulating blade 203 changes. In other words, there is a correlation between the shape of the toner container 204 and the type of the developing unit 210 that differs in the amount of toner stored therein and the amount of fog toner. Specifically, in the developing unit type and the fog toner amount, the X type having a large capacity reduces the probability that the toner is rubbed and increases the amount of poorly charged toner compared to the A type having a small capacity. The fog amount increases and the fog toner amount increases.
Therefore, in this embodiment, the waste toner life is determined based on the amount of fog that varies depending on the rotation speed of the developing roller and the developing unit type. That is, when determining the waste toner life that is one of the drum unit lifetimes, the rotation speed of the developing roller 201 and the information on the developing unit type written in the cartridge memory 211 provided in the developing unit 210 are included as one of the parameters. As a result, the waste toner life is determined by adding the fog toner amount corresponding to the fog amount that varies depending on the rotation speed of the developing roller 201 and the development unit type information.
FIG. 9 shows the transition of the fog amount with respect to the rotation speed of the developing roller 210 of the A type capable of forming 1000 sheets of images with a standard 5% printing rate document and the X type developing unit 210 capable of forming 2000 sheets of images. The developing roller 201 of this embodiment rotates 10 times per A4 size recording material. The number of rotations of the developing roller can be measured by integrating the driving time of the motor that drives the developing roller 201. Further, since the number of rotations of the developing roller per A4 size recording material is constant, it can be converted into the number of formed images.
The number of rotations of the developing roller is stored in the cartridge memory 211 of the developing unit 210. In the cartridge memory 211, the type of the developing unit 210 is also stored. The cartridge memory 211 may store information on the nominal life, and the image forming apparatus main body may distinguish the type of the developing unit 210 from the information on the nominal life.
The image forming apparatus main body, for each type according to the type, are plurality fog amount of the reference table (see table) to the developing roller rotational speed. In this reference table, the relationship between the rotation speed of the developing roller and the fog amount that changes in accordance with the rotation speed of the developing roller is determined in advance. In addition, the fog amount for each type of the development unit 210 can be calculated by having only one reference table for the fog amount with respect to the rotation speed of the developing roller and performing arithmetic processing using the development unit type as a coefficient.
Here, in the image forming apparatus main body, the print portion% exposed by the laser beam is calculated by pixel count for each image formation. At the same time, a value obtained by subtracting the exposed printed part% from the number of pixels per A4 size recording material, that is, the non-exposed part% not exposed is calculated.

(Waste toner life calculation method)
A method for calculating the waste toner life will be described. In this embodiment, the amount of toner that can be stored in the cleaner container 208 (the capacity of the cleaner container 208) is 20 g. Further, the developing unit 210 consumes 20 mg of toner for image formation of a standard 5% printing rate original. That is, 4 mg of toner is consumed per 1% of image formation.
If the exposed printed part% is calculated, the developing unit 210 consumes toner for the exposed part. Therefore, as the residual toner amount, the toner consumed amount for the printed part% is multiplied by 10%. It can be calculated by value. For example, in 5% printing, 20 mg of toner is consumed, and 2 mg, which is 10%, is stored in the cleaner container 208 as the amount of residual toner. The fog toner is toner that adheres to a region where a toner image is not formed. First, the non-printing portion% is calculated, and the developing roller rotation speed and the developing unit type at this time are read from the cartridge memory 211 of the developing unit 210. Recognizing the developing unit type, an appropriate reference table for the fog toner amount with respect to the rotation speed of the developing roller is selected, and the fog amount is derived from this reference table. For example, when the number of rotations of the developing roller of 1000 A type cartridges is 20000, the fog amount is 2%. Here, the fog toner amount per 1% fog amount is 0.4 mg. When an image of a document having a 5% printing rate is formed, the non-printing portion% is 95%. That is, as the fog toner amount, a value obtained by multiplying 0.95, 2 and 0.4 is calculated. Eventually, 0.76 mg is stored in the cleaner container 208 as a fog toner amount.
Therefore, the waste toner amount is calculated by adding the transfer residual toner amount and the fog toner amount. The waste toner life is calculated by adding the amount of toner remaining after transfer and the amount of fog toner to the amount of toner that can be accommodated in the cleaner container 208 (capacity of the cleaner container 208), and the cumulative amount of waste toner up to the previous time (the amount of cumulative removed developer). It is calculated by subtracting. In the above-described example, assuming that 2.76 mg of waste toner has been accommodated in the cleaner container 208 this time, it is subtracted together with the accumulated waste toner amount from 20 g which is the capacity of the cleaner container 208. It is also possible to indicate this as a ratio with respect to the cleaner container 208, for example, the remaining amount%.

(Waste toner life calculation routine 2)
A waste toner life calculation routine 2 for executing the above-described waste toner life calculation method is shown as a flowchart in FIG. FIG. 10 is a diagram illustrating a waste toner life calculation routine 2 according to the present embodiment.
When the waste toner life calculation routine 2 shown in FIG. 10 is executed, first, in S401, an image forming operation is performed.
In S402 to S403, a transfer residual toner amount is calculated. In S402, the print part% is calculated from the pixel count. In S403, the remaining toner amount is calculated by multiplying the print portion% by a predetermined coefficient (for example, 10%).
In S404 to S409, the amount of fog toner is calculated. In S404, the non-printing portion% is calculated from the pixel count. In step S405, the development unit type information is read from the cartridge memory 211 of the development unit 210. In step S406, a corresponding fog amount reference table is selected from the read development unit type information. In S407, the developing roller rotation speed is read from the cartridge memory 211 of the developing unit 210. In S408, the developing roller rotation speed read in S407 is taken into the reference table shown in FIG. 9 selected in S406, and the fog amount is derived. In step S409, the fogging amount by the image forming operation is calculated by multiplying the non-printing portion% by the fogging amount and the fogging toner amount per 1% fogging amount.
In S410, the amount of residual toner calculated in S403 and the amount of fog toner calculated in S409 are calculated, and the amount of waste toner due to the current image forming operation is calculated.
In S411, the waste toner life is calculated by subtracting the waste toner amount by the current image forming operation calculated in S410 and the accumulated waste toner amount up to the previous time from the capacity of the cleaner container 208.
In S412, the developing roller rotation speed of the cartridge memory 211 of the developing unit 210 is updated.
In S413, the waste toner life in the cartridge memory 212 of the drum unit 209 is updated to the waste toner life calculated in S411.

  In the present embodiment described above, the waste toner lifetime calculation method in the configuration in which one developing unit 210 as the second unit acts on the drum unit 209 as the first unit has been described. In particular, in this embodiment, since different types of second units can be mounted, the waste toner life of the first unit is accurately calculated based on the type stored in the cartridge memory 211 of the second unit and the rotation speed of the developing roller. can do. For this reason, even if the first unit and the second unit can be separately attached to and detached from the image forming apparatus main body, the waste toner life of the first unit can be accurately calculated.

<Example 3>
(Image forming device)
Next, Example 3 will be described. In this embodiment, the photosensitive layer 205 of the photosensitive drum 205 is further adapted to the image forming apparatus described in the second embodiment. In the present embodiment, the description overlapping that of the second embodiment is omitted.
In this embodiment, a DC voltage of −1000 V is applied to the charging roller 206 to charge the surface of the photosensitive drum 205 to about −500 V. This potential is referred to as dark portion potential Vd. Waiting for the dark portion potential Vd of the photosensitive drum 205 to be stabilized, the photosensitive drum 205 is exposed by laser light from the laser optical device 213 serving as exposure means, and an electrostatic latent image is formed on the surface thereof. The surface potential of the exposed part is about −100V. This potential is called a bright portion potential Vl. By applying a DC voltage of −300 V to the developing roller 201 and electrostatically adhering the thin layer coated toner to the light portion potential Vl as described above, the electrostatic latent image is converted into a toner image. Visualize development as The visualized toner image is electrostatically transferred to the recording material 215 by applying a DC voltage of +1500 V to the transfer roller 214.

(Thinner drum thinning)
A phenomenon in which toner adheres to the dark portion potential Vd instead of the light portion potential Vl to be originally attached due to poor charging of the toner coated on the developing roller 201 with a thin layer is called fogging. Is called fog toner. Further, as described above, the toner that is not successfully transferred from the visualized toner image to the recording material 215 and remains on the photosensitive drum 205 is referred to as “transfer residual toner”.
The fog toner tends to change in the amount of adhesion due to the potential difference between the dark portion potential Vd and the DC voltage applied to the developing roller 201. In the image forming apparatus of this embodiment, the fog difference tends to increase. The amount also tends to increase.
In the present embodiment, there are two types of toners that are removed and collected in the cleaner container 208, that is, untransferred toner and fog toner, and by estimating the amount of these toners, the life of the waste toner can be estimated.

The photosensitive drum 205 in this embodiment has a photosensitive layer with a layer thickness of 30 μm on an aluminum cylinder at the start of use. The photosensitive layer is scraped and thinned by repeating image formation by the action of the charging roller 206 and the cleaning blade 207. The degree of thinning relates to the number of sheets of recording material that is the number of image formations, and the thinning is performed at -2 μm / 1000 sheets. The photosensitive drum 205 can form an image until the photosensitive layer becomes 10 μm. If the photosensitive layer 205 is made thinner than this, the dark portion potential Vd is not stable and a desired electrostatic latent image cannot be formed. Therefore, the photoconductor drum 205 has a life when 10000 sheets of images are formed.
As the photosensitive layer becomes thinner, the dark portion potential Vd, which is the surface potential of the photosensitive drum 205, increases in the negative direction at 10 V / μm. For example, when the photosensitive layer reaches 20 μm, the surface of the photosensitive drum 205 is charged to about −600V. In the initial stage of use of the photosensitive drum 205, the potential difference between the dark portion potential Vd and the DC voltage applied to the developing roller 201 was 200V, whereas the potential difference becomes 300V when the photosensitive layer reaches 20 μm. Therefore, as the photosensitive layer becomes thinner, the potential difference increases, so that the toner is easily attracted to the photosensitive drum 205, and the fog toner amount tends to increase.
On the other hand, since the transfer residual toner acts on the recording material 215 from the visualized toner image, it acts on the bright portion potential Vl in the configuration of this embodiment. Therefore, if the light portion potential Vl does not change even when the photosensitive layer of the photosensitive drum 205 is thinned, the transfer residual toner does not show an increasing tendency.

(Cabritoner)
The fog toner will be described. As the developing roller 201 rotates, the toner T is thinly coated on the developing roller 201 by the action of the supply roller 202 and the regulating blade 203. In this process, the toner T is rubbed and its own charging performance is lowered. Along with this, the amount of poorly charged toner contained in the thin coat increases. That is, there is a correlation between the rotation speed of the developing roller 201 and the fog toner amount. Specifically, the rotational speed of the developing roller 201 and the fog toner amount have a relationship in which the fog amount increases and the fog toner amount increases as the rotational speed of the developing roller 201 increases. Here, the rotation speed of the developing roller 201 corresponds to the degree of use of the developer carrier of the present invention.
Further, the probability that the toner moves to the vicinity of the developing roller 201 and is rubbed by the action of the supply roller 202 and the regulating blade 203 changes with respect to the amount of toner stored in the toner storage container 204. In other words, there is a correlation between the developing unit type in which the shape of the toner storage container 204 and the amount of toner stored therein differ, and the fog toner amount. Specifically, in the developing unit type and the fog toner amount, the X type having a large capacity reduces the probability that the toner is rubbed and increases the amount of poorly charged toner compared to the A type having a small capacity. The fog amount increases and the fog toner amount increases.
Further, as described above, there is a correlation between the thinning of the photosensitive drum 205 and the amount of fog toner. Specifically, the thinning of the photosensitive drum 205 and the amount of fog toner have a relationship in which the fog toner amount increases as the thickness of the photosensitive drum decreases. Here, the layer thickness of the photosensitive layer of the photosensitive drum to be thinned corresponds to the degree of use of the electrostatic latent image carrier of the present invention.
Therefore, in this embodiment, the waste toner life is determined based on the number of rotations of the developing roller, the developing unit type, and the layer thickness of the photosensitive drum photosensitive layer of the drum unit 209. That is, the amount of fog that changes the waste toner lifetime, which is one of the drum unit lifetimes, according to the rotation speed of the developing roller 201 and the information of the development unit type, is determined according to the layer thickness information of the photosensitive drum. This is determined by adding the amount of fog toner obtained after correction. Here, the rotation speed of the developing roller 201 and information on the developing unit type are written in a cartridge memory 211 provided in the developing unit 210. Information on the layer thickness of the photosensitive layer of the photosensitive drum is written in a cartridge memory 212 provided in the drum unit 209.
FIG. 11 shows the development of the A type capable of forming 1000 images with a standard 5% printing rate original and the X type capable of forming 2000 images when the photosensitive layer in the initial use of the photosensitive drum 205 has a layer thickness of 30 μm. The transition of the fog amount with respect to the rotation speed of the developing roller of the unit 210 is shown. The developing roller 201 of this embodiment rotates 10 times per A4 size recording material. The number of rotations of the developing roller can be measured by integrating the driving time of the motor that drives the developing roller 201. Further, since the number of rotations of the developing roller per A4 size recording material is constant, it can be converted into the number of formed images. Further, FIG. 11 also shows the transition of the fog amount with respect to the rotation speed of the developing roller of the developing unit 210 when the photosensitive layer of the photosensitive drum 205 reaches 20 μm. In the initial stage of use of the photosensitive drum, the potential difference between the dark portion potential Vd and the DC voltage applied to the developing roller 201 was 200 V. However, when the photosensitive layer reached a layer thickness of 20 μm, the potential difference became 300 V. As the layer is reduced, the amount of fog toner increases at that rate.
The number of rotations of the developing roller is stored in the cartridge memory 211 of the developing unit 210. The cartridge memory 211 also stores a development unit type.
The image forming apparatus main body, for each type, and plurality fog amount of the reference table (see table) to the developing roller rotational speed. In this reference table, the relationship between the rotation speed of the developing roller and the fog amount that changes in accordance with the rotation speed of the developing roller is determined in advance. In addition, the fog amount for each type of the development unit 210 can be calculated by having only one reference table for the fog amount with respect to the rotation speed of the developing roller and performing arithmetic processing using the development unit type as a coefficient.
The layer thickness of the photosensitive layer of the photosensitive drum 205 correlates with the number of sheets of recording material that is the number of image formations. The number of sheets passed can be measured by the main body of the image forming apparatus. The thickness of the photosensitive drum photosensitive layer can be converted with a predetermined coefficient with respect to the number of sheets passed. It can also be calculated as a ratio to the layer thickness of the photosensitive drum photosensitive layer. In this embodiment, the converted information about the thickness of the photosensitive drum photosensitive layer is stored in the cartridge memory 212 of the second storage unit provided in the drum unit 209. Further, as the information stored in the cartridge memory 212, the number of sheets passed before being converted into the layer thickness of the photosensitive drum photosensitive layer may be stored. Then, it may be converted into the layer thickness of the photosensitive drum photosensitive layer from the number of passing sheets at the time of reading.
Here, in the image forming apparatus main body, the print portion% exposed by the laser beam is calculated by pixel count for each image formation. At the same time, a value obtained by subtracting the exposed printed part% from the number of pixels per A4 size recording material, that is, the non-exposed part% not exposed is calculated.

(Waste toner life calculation method)
A method for calculating the waste toner life will be described. In this embodiment, the amount of toner that can be stored in the cleaner container 208 (the capacity of the cleaner container 208) is 20 g. Further, the developing unit 210 consumes 20 mg of toner for image formation of a standard 5% printing rate original. That is, 4 mg of toner is consumed per 1% of image formation.
If the exposed printed part% is calculated, the developing unit 210 consumes toner for the exposed part. Therefore, as the residual toner amount, the toner consumed amount for the printed part% is multiplied by 10%. It can be calculated by value. For example, in 5% printing, 20 mg of toner is consumed, and 2 mg, which is 10%, is stored in the cleaner container 208 as the amount of residual toner.
The fog toner is toner that adheres to an unexposed area where a toner image is not formed. First, the non-printing portion% is calculated, and the developing roller rotation speed and the developing unit type at this time are read from the cartridge memory 211 of the developing unit 210. Recognizing the developing unit type, an appropriate reference table for the fog toner amount with respect to the rotation speed of the developing roller is selected, and the fog amount is derived from this reference table. For example, when the number of rotations of the developing roller of 1000 A type cartridges is 20000, the fog amount is 2%. Further, the layer thickness of the photosensitive drum photosensitive layer is read from the cartridge memory 212 of the drum unit 209. For example, when the layer thickness of the photosensitive layer is 20 μm, the potential difference between the dark portion potential Vd and the developing roller applied bias is 300V. Since the amount of fog in the reference table is a value when the potential difference is 200 V, it is calculated as a predetermined coefficient, that is, a value that is multiplied by 1.5 in this embodiment. Therefore, 2% is multiplied by 1.5. Here, the fog toner amount per 1% fog amount is 0.4 mg. When an image of a 5% printed document is formed, the non-printed portion% is 95%. That is, as the fog toner amount, a value obtained by multiplying 0.95, 2, 1.5, and 0.4 is calculated. Eventually, 1.14 mg is stored in the cleaner container 208 as a fog toner amount.
Therefore, the waste toner amount is calculated by adding the transfer residual toner amount and the fog toner amount. The waste toner life is calculated by adding the amount of toner remaining after transfer and the amount of fog toner to the amount of toner that can be accommodated in the cleaner container 208 (capacity of the cleaner container 208), and the cumulative amount of waste toner up to the previous time (the amount of cumulative removed developer). It is calculated by subtracting. In the above-described example, assuming that 3.14 mg of waste toner has been accommodated in the cleaner container 208 this time, it is subtracted together with the accumulated waste toner amount from 20 g which is the capacity of the cleaner container 208. It is also possible to indicate this as a ratio with respect to the cleaner container 208, for example, the remaining amount%.

(Waste toner life calculation routine 3)
A waste toner life calculation routine 3 for executing the above-described waste toner life calculation method is shown as a flowchart in FIG. FIG. 12 is a diagram illustrating a waste toner life calculation routine 3 according to the present embodiment. Note that the description of the same processing as the waste toner life calculation routine 2 shown in FIG.
When the waste toner life calculation routine 3 shown in FIG. 12 is executed, steps S401 to S407 are the same as the waste toner life calculation routine 2 shown in FIG.
In S501, the rotation speed of the developing roller read out in S407 is taken into a reference table such as that shown in FIG. 11 selected in S406, and the photosensitive drum 205 derives the initial standard fog amount. In S502, information on the layer thickness of the photosensitive drum photosensitive layer is read from the cartridge memory 212 of the drum unit 209. In S503, the corrected fog amount is calculated by multiplying the reference fog amount derived in S501 by a predetermined coefficient corresponding to the layer thickness of the photosensitive drum photosensitive layer read in S502. In step S504, the amount of fog toner due to the image forming operation is calculated by multiplying the non-printed portion% by the corrected fog amount and the fog toner amount per 1% fog amount.
In S505, the amount of residual toner calculated in S403 and the amount of fog toner calculated in S504 are calculated, and the amount of waste toner due to the current image forming operation is calculated.
In S <b> 506, the waste toner life is calculated by subtracting the waste toner amount by the current image forming operation calculated in S <b> 505 and the accumulated waste toner amount until the previous time from the capacity of the cleaner container 208.
In step S507, the developing roller rotation speed of the cartridge memory 211 of the developing unit 210 is updated.
In S508, the layer thickness of the photosensitive drum photosensitive layer in the cartridge memory 212 of the drum unit 209 is updated.
In S509, the waste toner life in the cartridge memory 212 of the drum unit 209 is updated to the waste toner life calculated in S506.

  In the present embodiment described above, the waste toner lifetime calculation method in the configuration in which one developing unit 210 as the second unit acts on the drum unit 209 as the first unit has been described. In particular, in this embodiment, since different types of second units can be mounted, the waste toner life of the first unit is accurately calculated based on the type stored in the cartridge memory 211 of the second unit and the rotation speed of the developing roller. can do. Further, considering that the amount of fog toner increases as the photosensitive drum photosensitive layer is thinned, the fog amount is based on the photosensitive drum photosensitive layer thickness stored in the cartridge memory 212 of the first unit. And the waste toner life can be accurately calculated. For this reason, even if the first unit and the second unit can be separately attached to and detached from the image forming apparatus main body, the waste toner life of the first unit can be accurately calculated.

  In the above embodiment, the developing roller rotation speed is used as the degree of use of the developer carrying member, which is one of the parameters for calculating the amount of waste toner to be removed every image formation. However, in order to see the deterioration of the toner in the toner container, the developing roller rotation time may be used as a parameter in addition to the developing roller rotation speed as the degree of use of the developer carrier. Further, the developing roller rotation speed and the developing roller rotation time may be combined as the degree of use of the developer carrier.

1: photosensitive drum, 5: developing device, 25: developing roller, 52: cartridge memory, 61: belt, 71: cleaner container, 201: developing roller, 205: photosensitive drum, 208: cleaner container, 209: drum unit, 210: Development unit 211: Cartridge memory

Claims (7)

An electrostatic latent image carrier;
A developing device having a developer carrying member disposed opposite to the electrostatic latent image carrying member, and developing the electrostatic latent image formed on the electrostatic latent image carrying member into a developer image;
A cleaner container containing the removed developer removed from the electrostatic latent image carrier after the developer image is transferred to the transfer body;
With
The electrostatic latent image carrier and the cleaner container are provided in a first unit, the developing device is provided in a second unit separate from the first unit, and the first unit and the second unit are devices. An image forming apparatus detachable from a main body,
In the image forming apparatus that calculates the amount of removed developer that is removed every image formation, and calculates the life of the cleaner container from the amount of cumulative removed developer that is accommodated in the cleaner container.
A first storage unit is provided in the second unit for storing the usage level of the developer carrier.
One of the parameters for calculating the amount of removed developer that is removed for each image formation includes the degree of use of the developer carrier stored in the first storage unit ,
The degree of use of the developer carrier and the fogging of the developer that changes depending on the degree of use and adheres to an area of the electrostatic latent image carrier that does not become an electrostatic latent image when developed by the developing device. A reference table with a predetermined relationship with the quantity is provided,
Calculating the amount of removed developer to be removed for each image formation based on the amount of fog derived by taking the degree of use of the developer carrier stored in the first storage unit into the reference table ; An image forming apparatus. A plurality of the developing devices are provided,
A primary transfer member to which a developer image is transferred from the electrostatic latent image carrier in order to superimpose developer images developed by a plurality of the developing devices;
The developer of the electrostatic latent image carrier is transferred to the primary transfer body when the developer image is transferred to the primary transfer body, which varies depending on the usage level of the developer carrier and the usage level. A first reference table that predetermines a relationship with a primary transfer efficiency that is a ratio;
The degree of use of the developer carrier and the development of the primary transfer body when another developer image is transferred onto the developer image transferred to the primary transfer body, which changes according to the degree of use. A second reference table that predetermines the relationship with the retransfer residual rate, which is the rate at which the agent remains without being transferred to the electrostatic latent image carrier,
Further comprising
Based on the primary transfer efficiency and the retransfer residual rate derived by taking the degree of use of the developer carrier stored in the first storage unit into the first reference table and the second reference table. The image forming apparatus according to claim 1, wherein an amount of the removed developer to be removed is calculated. Before hexane irradiation table, provided in plural in accordance with the plurality of types of quantities for accommodating the developer is different from the second unit,
It said second select pre hexane irradiation table from unit type, fogging the degree use of said developer carrying member which is stored in the first storage unit is derived incorporated into hexane irradiation table before said selected based on the amount, an image forming apparatus according to claim 1 or 2, characterized in that to calculate the amount of the removed developer to be removed for each image formation. The first unit is provided with a second storage unit that stores the degree of use of the electrostatic latent image carrier.
Based fog amount derived from the previous hexane irradiation table fog amount was corrected by about the use of the second stored in the storage unit the electrostatic latent image bearing member, the removed developer to be removed for each image forming the image forming apparatus according to any one of claims 1 to 3, characterized in that to calculate the amount of. An electrostatic latent image carrier;
A developing device having a developer carrying member disposed opposite to the electrostatic latent image carrying member, and developing the electrostatic latent image formed on the electrostatic latent image carrying member into a developer image;
A cleaner container containing the removed developer removed from the electrostatic latent image carrier after the developer image is transferred to the transfer body;
A Bei obtain an image forming apparatus,
In the image forming apparatus that calculates the amount of removed developer that is removed every image formation, and calculates the life of the cleaner container from the amount of cumulative removed developer that is accommodated in the cleaner container.
Providing a first storage unit for storing the degree of use of the developer carrier;
One of the parameters for calculating the amount of removed developer that is removed for each image formation includes the degree of use of the developer carrier stored in the first storage unit,
The degree of use of the developer carrier and the fogging of the developer that changes depending on the degree of use and adheres to an area of the electrostatic latent image carrier that does not become an electrostatic latent image when developed by the developing device. A reference table with a predetermined relationship with the quantity is provided,
Calculating the amount of removed developer to be removed for each image formation based on the amount of fog derived by taking the degree of use of the developer carrier stored in the first storage unit into the reference table ; An image forming apparatus. A plurality of the developing devices are provided,
A primary transfer member to which a developer image is transferred from the electrostatic latent image carrier in order to superimpose developer images developed by a plurality of the developing devices;
The developer of the electrostatic latent image carrier is transferred to the primary transfer body when the developer image is transferred to the primary transfer body, which varies depending on the usage level of the developer carrier and the usage level. A first reference table that predetermines a relationship with a primary transfer efficiency that is a ratio;
The degree of use of the developer carrier and the development of the primary transfer body when another developer image is transferred onto the developer image transferred to the primary transfer body, which changes according to the degree of use. A second reference table that predetermines the relationship with the retransfer residual rate, which is the rate at which the agent remains without being transferred to the electrostatic latent image carrier,
Further comprising
Based on the primary transfer efficiency and the retransfer residual rate derived by taking the degree of use of the developer carrier stored in the first storage unit into the first reference table and the second reference table. The image forming apparatus according to claim 5 , wherein an amount of the removed developer to be removed is calculated. The provided second storage unit for storing the order of use before Kisei latent image bearing member,
Based fog amount derived from the previous hexane irradiation table fog amount was corrected by about the use of the second stored in the storage unit the electrostatic latent image bearing member, the removed developer to be removed for each image forming The image forming apparatus according to claim 5, wherein an amount of the image is calculated.

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