JP7362362B2 - Image forming device - Google Patents

Description

The present invention relates to an image forming apparatus such as a copying machine, a printer, a facsimile machine, and a multifunctional device having multiple functions thereof.

The image forming apparatus includes a developing device that develops an electrostatic latent image formed on an image carrier such as a photosensitive drum using toner. The developing device includes a regulating member that faces the developer carrier with a predetermined gap therebetween, and the regulating member regulates the layer thickness (amount) of the developer carried by the developer. A thick layer of developer is conveyed to an area facing the image carrier. In this opposing region, developer is supplied from the developer carrier to the image carrier to develop the electrostatic latent image with toner (Patent Document 1).

Japanese Patent Application Publication No. 2015-34929

Here, the regulating member gradually wears out due to contact with the developer. When the gap between the regulating member and the developer carrier increases due to wear, the layer thickness of the developer carried on the developer carrier after passing through the regulating member increases, and the developer is developed in the area facing the image carrier. The agent will remain and cause image defects. In this case, the developing device has reached the end of its service life and must be replaced. Therefore, it is required to accurately predict the replacement life of the developing device due to wear of such a regulating member.

SUMMARY OF THE INVENTION An object of the present invention is to provide a configuration that can accurately predict the replacement life of a developing device due to wear of a regulating member.

The image forming apparatus of the present invention is a cartridge that is removably attached to the image forming apparatus and includes a developing device that develops an electrostatic latent image formed on an image carrier with toner, the cartridge including a toner and a carrier. a developer container that accommodates a developer, a developer carrier that rotates while supporting the developer in the developer container, and a developer that faces the developer carrier with a predetermined gap therebetween and that is The cartridge has a regulating member that regulates the amount of developer that has been applied, and a concentration detection means that detects the toner concentration in the developer container, and a toner concentration detected by the concentration detection means and a display means for displaying information regarding replacement of the cartridge based on the distance traveled, the display means configured to display information regarding replacement of the cartridge based on the distance traveled by the developer carrying member, and the display means displays information regarding replacement of the cartridge based on the distance traveled by the toner cartridge, and the display means is configured to display information regarding replacement of the cartridge based on the distance traveled by the developer carrying member; Assuming that the density is constant, the information regarding replacement of the cartridge is better when the toner density is higher than the first density than when the toner density is the first density. It is characterized by being displayed slowly .

Further, the image forming apparatus of the present invention is a cartridge that is removably attached to the image forming apparatus and includes a developing device that develops an electrostatic latent image formed on an image bearing member with toner, and the cartridge includes a developing device that develops an electrostatic latent image formed on an image carrier with toner. a developer container that contains a developer, a developer carrier that rotates while supporting the developer in the developer container, and a developer carrier that faces the developer carrier through a predetermined gap and that The cartridge includes a regulating member that regulates the amount of developer carried thereon, a concentration detection means that detects the toner concentration in the developer container, a toner concentration detected by the concentration detection means, and the developer carried. transmitting means for transmitting information regarding replacement of the cartridge to an external device based on the traveling distance of the developer carrier; Assuming that the toner concentration detected by the means is constant, when the toner concentration is higher than the first concentration, the second concentration is higher than when the toner concentration is the first concentration. The present invention is characterized in that information regarding cartridge replacement is transmitted to the external device late .

According to the present invention, the replacement life of the developing device due to wear of the regulating member can be accurately predicted.

1 is a schematic cross-sectional view of an image forming apparatus according to a first embodiment; FIG. FIG. 1 is a schematic configuration diagram of an image forming section according to the first embodiment. FIG. 1 is a block diagram showing a system configuration of an image forming apparatus according to a first embodiment. FIG. 1 is a schematic cross-sectional view of a developing device according to a first embodiment. FIG. 2 is a partially omitted view of the developing device according to the first embodiment as seen from above. FIG. 1 is a schematic configuration diagram showing a developer replenishment device according to a first embodiment. A graph showing the relationship between video count and toner consumption. 7 is a graph showing the relationship between the difference (ΔTD) between the target toner concentration and the detected toner concentration and the toner replenishment amount (second replenishment amount) in the inductance method. FIG. 3 is a schematic diagram showing how the layer thickness of the developer is regulated in the vicinity of the regulation blade. FIG. 3 is a control block diagram for predicting the amount of wear of the regulating blade and determining the lifespan of the developing device according to the first embodiment. FIG. 2 is a table showing the relationship between linear rotation speed and wear rate of the developing sleeve according to the first embodiment. FIG. 5 is a table showing the relationship between average toner density and correction coefficient β according to the first embodiment. A graph showing the relationship between the total amount of wear of the regulating blade and the amount of developer coating. 7 is a flowchart of control for predicting the amount of wear of the regulating blade and determining the lifespan of the developing device according to the first embodiment. A graph showing the relationship between the number of images formed and the amount of wear on the regulating blade. A graph showing the relationship between the number of images formed and the life of the developing device. 7 is a graph showing the relationship between the image ratio and the wear amount ratio of the regulating blade according to the second embodiment. 7 is a graph showing the relationship between the number of images formed and the toner deterioration index according to the second embodiment. 7 is a table showing the relationship between image ratio and saturated toner deterioration index according to the second embodiment. 7 is a table showing the relationship between the toner deterioration index and the correction coefficient β' according to the second embodiment. 7 is a flowchart of control for predicting wear amount of a regulating blade and determining life of a developing device according to a second embodiment. 7 is a graph showing changes in image ratio and toner deterioration index according to the second embodiment. Graph showing changes in image ratio and correction coefficient β'. A graph showing changes in the life of the developing device. FIG. 7 is a table showing the relationship between linear rotation speed and wear rate of the developing sleeve according to the third embodiment. FIG. 7 is a graph showing the relationship between linear rotation speed and wear rate of the developing sleeve according to the third embodiment. 10 is a flowchart of control for predicting wear amount of a regulating blade and determining life of a developing device according to a third embodiment; A graph showing the relationship between the number of images formed and the amount of wear on the regulating blade. A graph showing the relationship between the number of images formed and the life of the developing device. 7 is a graph showing the relationship between variations in the layer thickness regulating magnetic pole N1 of the developing sleeve and the magnetic force Fr around the regulating blade according to the fourth embodiment. 12 is a flowchart of control for predicting wear amount of a regulating blade and determining life of a developing device according to a fourth embodiment. 12 is a table showing the relationship between the gap D between the developing sleeve and the regulating blade and the correction coefficient σ according to the fifth embodiment. 12 is a graph showing the relationship between the gap D between the developing sleeve and the regulating blade, the amount of developer coating, and the amount of wear of the regulating blade according to the fifth embodiment. A table showing the relationship between the initial gap amount and the wear threshold value d1 according to the fifth embodiment. 10 is a flowchart of control for predicting wear amount of a regulating blade and determining life of a developing device according to a fifth embodiment. A graph showing the relationship between the number of images formed and the amount of wear on the regulating blade. A graph showing changes in the life of the developing device.

<First embodiment>
A first embodiment will be described using FIGS. 1 to 16. First, the schematic configuration of the image forming apparatus of this embodiment will be explained using FIGS. 1 to 3.

[Image forming device]
The image forming apparatus 100 of this embodiment forms an image on a recording material according to image information from a host device such as a document reading device connected to the apparatus main body 101 or a personal computer (PC) communicably connected to the apparatus main body 101. Form. For example, a four-color full-color image of yellow (Y), magenta (M), cyan (C), and black (K) can be created using an electrophotographic image forming unit (described later) on paper or plastic sheet as a recording material. Form into a sheet of cloth, etc.

The image forming apparatus 100 of this embodiment is a four-unit tandem type image forming apparatus, and includes image forming units PY, PM, PC, and a plurality of image forming units that form yellow, magenta, cyan, and black images, respectively. Has PK. Then, while the intermediate transfer belt 51 as an intermediate transfer member included in the transfer device 5 moves in the direction of the arrow in FIG. ~Toner images (images) of each color formed with PK are superimposed. Then, a recorded image is obtained by transferring the superimposed toner images onto a recording material on this intermediate transfer belt 51.

In the following embodiments, the configurations of the image forming units PY, PM, PC, and PK are substantially the same except for different developing colors. Hereinafter, the image forming unit PK will be used as a representative example.

The image forming section PK includes a photosensitive drum 1 that is a drum-shaped photosensitive member and serves as an image carrier that carries an electrostatic latent image according to image information. On the outer periphery of the photosensitive drum 1, a charging roller 2 serving as a charging device, an exposure device 3 consisting of a laser exposure optical system, a developing device 4, a transfer device 5, and a cleaning device 7 are provided. The developing device 4 is supplied with developer from a replenishing developer storage container (toner cartridge) 8 . The transfer device 5 includes an intermediate transfer belt 51 as an intermediate transfer member. The intermediate transfer belt 51 is wound around a plurality of rollers and rotates in the direction of the arrow in FIG. Further, primary transfer members 52 are arranged at positions facing the photosensitive drums 1 of each image forming section via the intermediate transfer belt 51. Further, a secondary transfer roller 53 as a secondary transfer member is provided at a position facing one of the rollers around which the intermediate transfer belt 51 is wound.

During image formation, first, the charging roller 2 uniformly charges the surface of the rotating photosensitive drum 1. Next, an electrostatic latent image is formed on the photosensitive drum 1 by scanning and exposing the charged surface of the photosensitive drum 1 using the exposure device 3 in accordance with an image information signal. The electrostatic latent image formed on the photosensitive drum 1 is visualized as a toner image using toner of a developer using a developing device 4 .

The toner image formed on the photosensitive drum 1 is transferred onto the intermediate transfer belt 51 by the action of the primary transfer bias voltage applied to the primary transfer member 52 at the primary transfer nip where the intermediate transfer belt 51 and the photosensitive drum 1 are in contact with each other. is primarily transferred to. For example, when forming a four-color full-color image, toner images are sequentially transferred from each photosensitive drum 1 onto the intermediate transfer belt 51 from the image forming portion PY, and the four-color toner images are superimposed on the intermediate transfer belt 51. Multiple toner images are formed.

On the other hand, the recording material stored in the feeding cassette 9 is transferred onto the intermediate transfer belt 51 by a pickup roller, a conveyance roller, a registration roller, etc., into a secondary transfer nip portion where the intermediate transfer belt 51 and the secondary transfer roller 53 are in contact with each other. The toner image is conveyed in synchronization with the toner image. Then, the multiple toner images on the intermediate transfer belt 51 are transferred onto the recording material at the secondary transfer nip section by the action of the secondary transfer bias voltage applied to the secondary transfer roller 53.

Thereafter, the recording material separated from the intermediate transfer belt 51 is conveyed to the fixing device 6. The toner images transferred onto the recording material are heated and pressurized by the fixing device 6 to be melted and mixed, and are also fixed onto the recording material. After that, the recording material is discharged outside the machine.

The toner and other deposits remaining on the photosensitive drum 1 after the primary transfer process are collected by a cleaning device 7. Thereby, the photosensitive drum 1 is prepared for the next image forming process. In addition, adherents such as toner remaining on the intermediate transfer belt 51 after the secondary transfer process are removed by an intermediate transfer body cleaner 54.

Note that the image forming apparatus 100 of the present embodiment is capable of forming a single-color or multi-color image, such as a single-color black image, using image forming sections for a desired single color or some of four colors. is also possible.

Next, the system configuration of the image processing unit in the image forming apparatus 100 of this embodiment will be described using FIG. 3. Color image data is input to the image processing unit as RGB image data from an external device (not shown) such as a document scanner or a computer (information processing device) as necessary via an external input interface (external input I/F) 200. be done.

The LOG conversion unit 201 converts the luminance data of the input RGB image data into CMY density data (CMY image data) based on a look-up table (LUT) configured from data stored in the ROM 210 and the like. The masking/UCR unit 202 extracts black (K) component data from the CMY image data, and performs matrix calculation on the CMYK image data in order to correct color turbidity of recording color materials.

A lookup table unit (LUT unit) 203 uses a gamma lookup table (γ lookup table) to match the image data to the ideal gradation characteristics of the printer unit. Perform density correction. Note that the γ lookup table is created based on data developed on the RAM 211, and the contents of the table are set by the CPU 206.

The pulse width modulation unit 204 outputs a pulse signal with a pulse width corresponding to the level of image data (image signal) input from the LUT unit 203. Based on this pulse signal, the laser driver 205 drives a laser light emitting element of the exposure device 3, and irradiates the photosensitive drum 1 with the laser, thereby forming an electrostatic latent image.

The video signal counting unit 207 integrates the level (0 to 255 levels) of each pixel (at 600 dpi in this embodiment) of the image data input to the LUT unit 203 for one image. This image data integrated value is called a video count value. This video count value has a maximum value of 1023 when the output image is 255 levels all over the entire surface of one side of A4 paper. Note that if there is a restriction due to the circuit configuration, the video count value can be obtained by using the laser signal counting section 208 instead of the video signal counting section 207 and calculating the image signal from the laser driver 205 in the same way. is possible.

Further, the image forming control section 209 drives and controls the configuration of each section of each image forming station described above. For example, the laser driver 205 drives a laser light emitting element via the image forming control unit 209 using a pulse signal based on image data.

The image forming apparatus 100 also includes a display section 220 such as an operation panel. The display unit 220 serving as a display unit is disposed on the side where the user operates the image forming apparatus, that is, on the front side, and is capable of displaying various states of the image forming apparatus 100 and making various settings of the image forming apparatus 100. . For example, output from the CPU 206, which will be described in detail later, is displayed on the display unit 220. Note that various states of the image forming apparatus 100 may be displayed on an external terminal such as a personal computer connected to the image forming apparatus 100. In this case, output from CPU 206 is sent to the personal computer.

[Developing device]
Next, the configuration of the developing device 4 will be further explained with reference to FIGS. 4 and 5. The developing device 4 as a cartridge is removably attachable to the apparatus main body 101 (FIG. 1) of the image forming apparatus 100. It has a developer container 41 that contains a two-component developer containing a non-magnetic toner and a magnetic carrier. The developing container 41 is provided with a developing sleeve 44 as a developer carrier, and a magnet roll 44a that is fixedly disposed within the developing sleeve 44 and is made of a magnet as a magnetic field generating means. Furthermore, a regulating blade 42 for forming a thin layer of developer on the surface of the developing sleeve 44, and screw members 41d and 41e for stirring and transporting the developer in the developing container 41 are arranged.

The inside of the developer container 41 is divided into a developer chamber 41a and a stirring chamber 41b by a partition wall 41c extending in the vertical direction. A screw member 41d is arranged in the developing chamber 41a, and a screw member 41e is arranged in the stirring chamber 41b. Transfer portions 41f and 41g are provided at both ends of the partition wall 41c in the longitudinal direction (direction of the rotational axis of the developing sleeve 44) to allow the developer to pass between the developing chamber 41a and the stirring chamber 41b. In this embodiment, the developing chamber 41a and the stirring chamber 41b are arranged on the left and right in the horizontal direction, but a developing device in which the developing chamber 41a and the stirring chamber 41b are arranged vertically, or in other types of developing devices, may also be used. The present invention is applicable.

The screw members 41d and 41e are arranged substantially parallel to each other along the direction of the rotational axis of the developing sleeve 44. Then, the screw member 41d and the screw member 41e stir and convey the developer in opposite directions along the rotational axis direction of the developing sleeve 44 by the developing drive motor 230 (FIG. 10). In this manner, the developer is circulated within the developer container 41 via the delivery portions 41f and 41g by the screw members 41d and 41e. That is, due to the conveying force of the screw members 41d and 41e, the developer in the developing chamber 41a, whose toner concentration has decreased due to the toner consumed in the developing process, moves into the stirring chamber 41b via the one delivery section 41f.

Further, a replenishment port 43 for replenishing toner is provided at the most upstream part of the stirring chamber 41b, and the replenishment developer storage container 8, which serves as a replenishment container in which the replenishment toner shown in FIG. 5 is stored, is provided. I'm in touch. Further, the screw member 41e uniformizes the toner concentration under automatic toner replenishment control (hereinafter referred to as "ATR: Automatic Toner Replenisher" control). That is, the toner supplied at the replenishment port 43 and the developer consisting of the toner and magnetic carrier already in the stirring chamber 41b are stirred and conveyed to make the toner concentration uniform.

Here, as shown in FIG. 5, a toner concentration sensor as a concentration detection means is provided below the wall of the outside of the stirring chamber 41b (on the opposite side to the developing chamber 41a) so that its detection surface is exposed to the stirring chamber 41b. 45 are fixedly arranged. The toner concentration sensor 45 is an inductance sensor that detects the magnetic permeability inside the developer container, and detects the toner concentration (TD ratio) of the developer being conveyed by the screw member 41e, and outputs a voltage according to the detection result. do. Further, the toner concentration sensor 45 is disposed downstream of the center of the stirring chamber 41b in the developer transport direction and in front of the transfer section 41g that transfers the developer from the stirring chamber 41b to the developing chamber 41a.

The CPU 206 replenishes the developer from the replenishment developer storage container 8 using the above-mentioned ATR control. In this embodiment, the operation of the replenishing developer storage container 8 is controlled according to the image ratio during image formation, the density detection result of the patch image by the toner density sensor 45, and the patch image density detection sensor 55 (FIG. 2). Toner is supplied to the most upstream portion of the stirring chamber 41b. Then, the developer in the stirring chamber 41b, which is replenished with toner and stirred, moves to the developing chamber 41a via the other delivery section 41g. The patch image density detection sensor 55 has, for example, a light emitting part and a light receiving part, and is arranged to face the intermediate transfer belt 51 as shown in FIG. The reflected light is detected by the light receiving section. Thereby, the image density of the patch image as a control toner image formed on the intermediate transfer belt 51 is detected.

The developing chamber 41a of the developing device 4 is open at a position corresponding to the developing area facing the photosensitive drum 1, and the developing sleeve 44 is partially exposed in the opening 41j of the developing container 41. It is arranged so that it can rotate. In this embodiment, the developing sleeve 44 is made of a non-magnetic material and rotates in the direction of the arrow in FIG. 4 during the developing operation. Further, the developing sleeve 44 is a grooved sleeve in which a plurality of grooves are formed along the entire circumference in parallel to the rotational axis direction of the developing sleeve 44 on the outer peripheral surface. Note that the outer circumferential surface of the developing sleeve 44 may have a structure other than the plurality of grooves as described above. For example, it may be one in which a plurality of recesses are formed by blasting, or it may be one in which a plurality of recesses in a shape such as an ellipse, which is larger than the recess formed by blasting, are regularly formed. .

A magnet roll 44a having a plurality of magnetic poles along the circumferential direction is fixed inside the developing sleeve 44 as a magnetic field generating means. In this embodiment, a magnet roll having five magnetic poles magnetized was used. The S2 pole is an attraction magnetic pole that causes the developing sleeve 44 to carry the developer sent from the screw member 41d. The N1 pole is a layer thickness regulation magnetic pole that regulates the amount of developer transported to the development area. The S1 pole is a development pole that contributes to development. The N2 pole is a transporting magnetic pole that transports the developer. The S3 pole is a separating magnetic pole that strips off the developer supported on the developing sleeve 44.

The developer in the developing chamber 41a is supplied to the developing sleeve 44 by the screw member 41d, and the developer supplied to the developing sleeve 44 is deposited in a predetermined amount onto the developing sleeve 44 by the magnetic attraction pole S2 generated by the magnet roll 44a. is supported and forms a developer reservoir. The two-component developer (magnetic spike of developer) on the developing sleeve 44 is conveyed to the layer thickness regulating magnetic pole N1 as the developing sleeve 44 rotates. Then, the layer thickness (developer coating amount) is regulated by a regulation blade 42, which will be described later, and the toner is transported to a development area facing the photosensitive drum 1 to supply toner to the electrostatic latent image.

Thereafter, the developer on the developing sleeve 44 is transported to the inside of the developing container by maintaining the adsorption of the developer to the surface of the developing sleeve 44 by the transporting magnetic pole N2, and the developer is transported to the inside of the developing container by the separating magnetic pole S3. spaced from the sleeve surface. In this embodiment, the diameter of the developing sleeve 44 is 20 mm, the diameter of the photosensitive drum 1 is 30 mm, and the distance between the developing sleeve 44 and the photosensitive drum 1 is approximately 300 μm. With this configuration, development can be performed while the developer conveyed to the developing section is in contact with the photosensitive drum 1. At this time, a developing bias voltage in which a DC voltage and an AC voltage are superimposed is applied to the developing sleeve 44 from the power source. In this embodiment, a DC voltage of -500V and an AC voltage with a peak-to-peak voltage Vpp of 1800V and a frequency f of 12kHz were used.

By setting the rotational linear velocity (circumferential velocity) of the developing sleeve 44 faster than the rotational linear velocity of the photosensitive drum 1, toner can be supplied by increasing the amount of magnetic spikes of developer in contact with each unit area of the photosensitive drum 1. Increase the amount. In this embodiment, when plain paper is used as the recording material, the rotational linear velocity of the photosensitive drum 1 is 300 mm/s, and the rotational linear velocity of the developing sleeve 44 is 540 mm/s multiplied by the peripheral speed ratio of 1.8. Furthermore, when using cardboard with a basis weight of 100 g/m2 or ^more, the rotation linear speed of the photosensitive drum 1 is changed to 200 mm/s or 150 mm/s, and the rotation linear speed of the developing sleeve 44 is changed to 360 mm/s or 270 mm/s, respectively. becomes.

Generally, in the two-component magnetic brush development method as described above, application of an alternating current voltage increases development efficiency and produces a high-quality image, but conversely fog is more likely to occur. For this reason, fogging is prevented by providing a potential difference between the DC voltage applied to the developing sleeve 44 and the charging potential of the photosensitive drum 1 (ie, the white background potential). In this embodiment, the potential difference between the DC voltage applied to the developing sleeve 44 and the charging potential of the photosensitive drum 1 is set to 150 V, thereby making it difficult to generate fog.

The regulating blade 42 as a regulating member is made of resin. That is, the regulating blade 42 is a resin member extending along the rotational axis direction of the developing sleeve 44, and is molded integrally with the developing container 41. As the resin material used for the regulation blade 42, one having relatively high rigidity, such as PC+AS resin material or PC+ABS resin material, is selected. Note that, for the regulating blade 42, in addition to such a resin material, a soft metal such as an aluminum alloy may be used, for example. Furthermore, instead of being formed integrally with the developer container 41, the regulating blade 42 may be formed separately from the developer container 41 and fixed to the developer container 41 with a fixing member such as a screw.

Further, the regulating blade 42 is disposed on the upstream side in the rotational direction of the developing sleeve 44 with respect to the opposing region facing the photosensitive drum 1 so as to face the developing sleeve 44 with a predetermined gap therebetween. Both the developer toner and the carrier pass between the regulating blade 42 and the developing sleeve 44 and are sent to the developing area.

Note that by adjusting the gap between the regulating blade 42 and the surface of the developing sleeve 44, the amount of developer carried on the developing sleeve 44 cut by the magnetic brush is regulated, and the amount of developer conveyed to the developing area can be controlled. be adjusted. In this embodiment, the regulating blade 42 regulates the amount of developer coated per unit area on the developing sleeve 44 to 30 mg/cm ² . Further, it is preferable that the gap between the regulating blade 42 and the developing sleeve 44 is 200 to 1000 μm, and in this embodiment, the gap is set to 300 μm.

[Replenishment device]
Next, a toner replenishment configuration will be described using FIG. 6. The developer replenishment device 80 of the present embodiment is based on a configuration in which a replenishment transport path 83 extends from the discharge port 82 of the replenishment developer storage container 8 and is connected to the replenishment port 43 of the developing device 4 . I will explain in detail. In the above-described developing device 4, the supply port 43 is provided at the most upstream side of the stirring chamber 41b and outside the developer circulation path. There is almost no developer in the developer circulation path in the developer transport member near the replenishment port 43, and only replenishment developer passes therethrough. The replenishment port 43 is connected to the lower end of a cylindrical member with a square cross section, which is a replenishment transport path 83. Further, the upper end, which is the other end of the cylindrical member, is connected to the discharge port 82 of the replenishment developer storage container 8 .

The replenishment developer storage container 8 has a configuration in which a spiral groove is cut in the inner wall of a cylindrical container, and a replenishment drive motor (not shown) is driven to rotate the replenishment developer storage container 8 itself. The replenishing developer is conveyed to the discharge port 82 by generating a conveying force in the longitudinal direction. The replenishment developer conveyed to the discharge port 82 is discharged to the replenishment transport path 83 through the discharge port 82 by air pressure generated by a pump 81 that makes the volume within the replenishment developer storage container 8 variable.

[Toner supply control]
Next, toner replenishment control according to this embodiment will be explained using FIGS. 7 and 8. In this embodiment, replenishment control is performed using both a video count replenishment method and an inductance replenishment method. FIG. 7 shows the relationship between toner consumption and video count value. In the video count replenishment method, the predicted toner consumption amount Tv predicted according to a predetermined video count is set as the first replenishment amount.

However, the relationship between the video count and the amount of toner consumption is not always the same due to individual differences in image forming apparatuses, deterioration over time, user usage environment, output images, etc. As shown in FIG. 7, a consumption error occurs even in the same video count. When a difference occurs between the predicted toner consumption amount and the actual toner consumption amount, the toner concentration within the developer container 41 increases or decreases. For this reason, an inductance replenishment method is also used in which the replenishment amount is determined based on the output of the toner concentration sensor 45 that detects the toner concentration.

FIG. 8 shows the relationship between the toner replenishment amount and the deviation between the toner concentration target value and the toner concentration in the inductance replenishment method. If the difference between the target toner concentration and the detected toner concentration is ΔTD, and the conversion rate to the replenishment toner amount, that is, the toner concentration feedback rate (FB rate) is Kp, the toner replenishment amount Ttd (second replenishment amount) in the inductance method can be expressed by the following formula.
Ttd=Kp×ΔTD...(1)

When the toner concentration is lower than the target value, the necessary amount of toner is replenished, and if it is higher than the target value, it is regarded as excess toner, and the toner concentration is kept constant by subtracting from the replenishment amount. Therefore, the amount of replenishment that is actually replenished in this embodiment is as shown in the following equation.
T=Tv-Ttd...(2)

Further, the toner density target value is changed according to the density detection result of the patch image by the patch image density detection sensor 55.

[Overview of developer]
Here, the two-component developer containing toner and carrier contained in the developer container 41 will be explained in detail. The toner has colored resin particles containing a binder resin, a colorant, and other additives as necessary, and colored particles to which an external additive such as colloidal silica fine powder is externally added. There is.

Examples of external additive particles include amorphous silica subjected to hydrophobic treatment, and fine particles of inorganic oxides such as titanium oxide and titanium compounds. It is preferable to control the powder fluidity and charge amount of the toner by externally adding these fine particles to the toner matrix. The particle size of the external additive particles is preferably about 1 nm to 100 nm. In this embodiment, 0.5 wt% of titanium oxide with an average particle size of 50 nm and 0.5 wt% and 1.0 wt% of amorphous silica with average particle sizes of 2 nm and 100 nm, respectively, are used. there was.

The toner is a negatively chargeable polyester resin, and preferably has a volume average particle diameter of 4 μm or more and 8 μm or less. Furthermore, in recent toners, toners with a low melting point or toners with a low glass transition point Tg (for example, Tg≦70° C.) are often used to improve fixing properties. Furthermore, the toner may contain wax in order to improve its separation after fixing. The developer of this embodiment is a pulverized toner containing wax.

Further, as the carrier, for example, surface oxidized or unoxidized metals such as iron, nickel, cobalt, manganese, chromium, rare earths, alloys thereof, or oxide ferrite can be suitably used. The manufacturing method is not particularly limited. The carrier has a weight average particle diameter of 20 to 60 μm, preferably 30 to 50 μm, and a resistivity of 10 ⁷ Ωcm or more, preferably 10 ⁸ Ωcm or more. In this embodiment, one with a resistance of 10 ⁸ Ωcm was used.

Note that the volume average particle diameter of the toner used in this embodiment was measured using the apparatus and method shown below. As a measuring device, an SD-2000 sheath flow electrical resistance particle size distribution measuring device (manufactured by Sysmex Corporation) was used. The measurement method is as shown below. That is, in 100 to 150 ml of an electrolytic aqueous solution of 1% NaCl aqueous solution prepared using primary sodium chloride, 0.1 ml of a surfactant, preferably an alkylbenzene sulfonate, is added as a dispersant, and 0.5 to 50 mg of the measurement sample is added. Add. The electrolytic aqueous solution in which the sample is suspended is dispersed using an ultrasonic disperser for about 1 to 3 minutes. Then, the particle size distribution of particles of 2 to 40 μm is measured using the SD-2000 sheath flow electrical resistance particle size distribution analyzer described above using a 100 μm aperture as an aperture to obtain a volume average distribution. The volume average particle diameter is obtained from the volume average distribution thus determined.

Further, for the resistivity of the carrier used in this embodiment, a sandwich type cell with a measurement electrode area of 4 cm and an inter-electrode spacing of 0.4 cm was used. The measurement was performed by applying a voltage E (V/cm) between both electrodes under a pressure of 1 kg to one electrode, and obtaining the resistivity of the carrier from the current flowing through the circuit.

The weight ratio of the toner in the two-component developer, that is, the toner concentration is approximately 9 wt%. This ratio should be appropriately adjusted depending on the amount of charge of the toner, the carrier particle size, the configuration of the image forming apparatus, the usage conditions, etc., and does not necessarily have to be in accordance with this numerical value. In this embodiment, the initial developer amount was 200 g and the toner concentration was 9%.

[Wear of regulation blade]
Next, wear of the regulating blade 42 will be explained using FIG. 9. FIG. 9 is a schematic diagram of regulating the layer thickness near the regulating blade 42 while the developing sleeve 44 is rotating. When the developer supported on the developing sleeve 44 approaches the layer thickness regulating magnetic pole N1 due to the rotation of the developing sleeve 44, it forms a magnetic spike. The gap between the developing sleeve 44 and the regulating blade 42 is set narrower than the length of the magnetic spike, and the magnetic spike that comes into contact with the regulating blade 42 is cut to the length of the gap and conveyed to the developing area. Therefore, the developer stagnates upstream of the regulating blade 42 in the rotational direction of the developing sleeve 44, and the stagnant developer tries to flow into the gap between the developing sleeve 44 and the regulating blade 42, increasing the developer density near the regulating blade 42. . At this time, the regulation blade 42 is worn out due to the sliding friction between the carrier and toner in the developer and the external additive.

The amount of wear of the regulating blade 42 is calculated using Ratner's wear formula,
V=K×N×v×t
It is indicated by.

here,
V: Amount of wear (mm ³ )
N: Vertical component of load on regulation blade (N)
v: moving speed of developer (mm/s)
t: time (s)
K: A coefficient that varies depending on the material of the developer and the regulation blade.

In particular, the characteristics of the developer vary depending on the usage environment of the user and the output image. When the characteristics of the developer change, the coefficient K, which varies depending on the material of the developer and the regulating blade 42, changes. Here, the characteristic of the developer includes, for example, toner density. Generally, carriers made of metal have a higher hardness than toners made of resin. Therefore, when the toner concentration decreases, the toner coverage rate on the carrier decreases (the exposed amount of carrier increases), and the regulation blade 42 becomes more likely to wear.

Further, the characteristics of the developer include the state of coating of the external additive on the surface of the toner. If images with a low image ratio continue, the toner remains in the developing device for a long time, and the external additive is released from the toner or embedded in the toner surface, resulting in so-called toner deterioration. Therefore, as toner deterioration progresses, the state of the external additive that comes into contact with the regulation blade 42 changes, so the amount of wear of the regulation blade 42 changes. As toner deterioration progresses, the coverage of the external additive to the toner decreases, and the regulating blade 42 becomes less likely to wear. Therefore, in this embodiment, the amount of wear of the regulation blade 42 is predicted according to changes in toner concentration.

[Determining the lifespan of the developing device based on the wear of the regulating blade]
Next, a method for predicting the amount of wear of the regulating blade 42 and determining the lifespan of the developing device will be described. In this embodiment, the amount of wear of the regulating blade 42 is predicted based on the traveling distance of the developing sleeve 44 and the toner concentration. FIG. 10 is a circuit block diagram for predicting the wear amount of the regulating blade 42 and determining the lifespan of the developing device in this embodiment. When the image forming operation is started, the CPU 206 drives the development drive motor 230, thereby rotationally driving the development sleeve 44. The CPU 206 includes a drive time calculation section 212, an average toner concentration calculation section 213, a replenishment amount calculation section 214, a toner deterioration index calculation section 215, a wear amount calculation section 216, and a developing device life calculation section 217, and performs various calculations. Note that in this embodiment, the toner deterioration index calculation unit 215 may be omitted. Further, in FIG. 10, the CPU 206 can communicate with the developing device memory tag 900 via the communication unit 901, but in this embodiment, the developing device memory tag 900 and the communication unit 901 may be omitted.

First, the driving time calculation unit 212 obtains the driving time t of the developing drive motor 230. The average toner density calculation unit 213 averages the toner density calculated according to the output of the toner density sensor 45 at a predetermined timing. The purpose of the averaging process is to reduce detection errors of the toner concentration sensor 45 and local variations in toner concentration within the developing device. In this embodiment, averaging is performed at the circulation cycle in which the developer circulates within the developer container 41. However, the method of toner density averaging processing is not limited to this.

The wear amount calculation unit 216 calculates the amount of wear on the regulating blade 42 as follows. In this embodiment, the timing for calculating the amount of wear of the regulating blade 42 is set for each image formation (for each sheet of recording material). However, the process is not limited to every image formation, but may be every multiple image formations. Alternatively, it may be calculated at fixed time intervals such as every second. Furthermore, it may be performed during execution of an image forming job (time between successive recording materials), after various adjustments have been made, or at or after the end of an image forming job.

Next, from the Ratner's wear equation described above, the wear amount Δd(m) of the m-th regulating blade 42 is defined as follows.
Δd(m)=Δt(m)×α(m)×β(m)...(3)

Here, Δd (m): Amount of wear in calculation interval m (μm)
Δt (m): Drive time of development drive motor (s)
α(m): Wear rate proportional to the rotational linear speed of the developing sleeve β(m): Correction coefficient according to the toner concentration of the developer.

α(m) is the amount of wear (wear rate) per unit time that is proportional to the rotational linear speed of the developing sleeve 44. As described above, the regulation blade 42 is likely to wear out due to contact with the carrier in the developer. Therefore, when the rotational linear speed of the developing sleeve 44 is high, there are many opportunities for the regulating blade 42 to come into contact with the developer, and the regulating blade 42 is likely to wear out. That is, when comparing cases where the rotational linear speed of the developing sleeve 44 is fast and slow, the travel distance (rotational linear speed x time) of the developing sleeve 44 in the same time is longer when the rotational linear speed is faster. When the developing sleeve 44 travels a long distance, the opportunity for contact between the regulating blade 42 and the developer increases accordingly, making the regulating blade 42 more likely to wear out.

FIG. 11 shows the wear rate of each developing sleeve 44 at a rotational linear speed at a toner concentration of 9%. As is clear from FIG. 11, the higher the rotational linear speed of the developing sleeve 44, the more likely the regulation blade 42 will wear out. In FIG. 11, the wear rate α (m) is shown for three stages of process speed (rotational linear speed of the photosensitive drum), but the wear rate α (m) can be set according to the process speed of the image forming apparatus. is preferred.

Further, β(m) is a correction coefficient depending on the toner concentration of the developer. As described above, the wear rate changes because the toner coverage rate on the carrier changes depending on the toner concentration. Therefore, in this embodiment, as described above, the amount of wear of the regulating blade 42 according to the traveling distance of the developing sleeve 44 is corrected according to the toner concentration.

FIG. 12 shows a table showing the relationship between the average toner density of the developer and the correction coefficient β. Based on a toner concentration of 9%, the correction coefficient β is changed depending on the toner coverage. As is clear from FIG. 12, the higher the toner concentration, the harder the regulating blade 42 will wear out, and the lower the toner concentration, the easier the regulating blade 42 will wear out. In addition, in the table of FIG. 12, linear interpolation is performed between tables.

Next, using the wear amount Δd (m) of the m-th piece and the total wear amount d (m-1) up to the previous time, the total wear amount of the m-th piece is:
d(m)=d(m-1)+Δd(m)...(4)
becomes.

In this embodiment, the amount of wear of the regulating blade 42 is predicted based on the traveling distance of the developing sleeve 44 and the toner concentration by using the above-described equations (3) and (4).

The developing device life calculating section 217 calculates the developing device life L based on the total wear amount d(m) calculated by the wear amount calculating section 216. FIG. 13 is a graph showing the total wear amount d(m) of the regulating blade 42 and the variation in the amount of developer coated on the developing sleeve 44 whose layer thickness (amount of developer) is regulated by the regulating blade 42. The amount of coating increases as the total amount of wear d(m) increases. And the coating amount is 45mg/cm²Exceeding this will cause image defects. Therefore, the total wear amount at this time is d₁(=10 μm) is used as a threshold value to determine the lifespan of the developing device. That is, the life L of the developing device is calculated using the following formula.
L=d(m)/dl ×100[%] ...(5)

Further, the CPU 206 displays the life L of the developing device calculated by the developing device life calculating unit 217 on a display unit 220 serving as a display means to notify the user. The life L of the developing device is notified to the user in 1% increments, and is counted up as the life of the developing device progresses. Then, when the life L of the developing device reaches a predetermined value Lth, a message prompting the user to replace the developing device is displayed on the display unit 220. In this embodiment, the lifespan L of the developing device corresponds to information regarding the lifespan of the cartridge, and the message prompting replacement of the developing device corresponds to information regarding cartridge replacement.

Further, the image forming apparatus 100 of this embodiment includes a notification unit 800 that can communicate with an external device such as an external server or a PC. At a predetermined timing, the CPU 206 uses the notification unit 800 to notify the serviceman of the current lifespan L of the developing device via the server, and urges the serviceman to systematically replace service parts. Then, when the life L of the developing device reaches a predetermined value Lth, the notification unit 800 notifies the server of replacement and prompts the service person to replace the parts. That is, the notification unit 800 serving as a transmitting means transmits information regarding cartridge replacement to an external device such as a server.

[Flow of calculating the lifespan of the developing device]
FIG. 14 shows a flowchart for calculating the life of the developing device in this embodiment. When the life prediction of the developing device is started, the CPU 206 obtains the driving time (developing driving time) Δt(m) of the developing drive motor 230 for each image formation (S101). Next, the CPU 206 selects the wear rate α (m) from the table (FIG. 11) of the rotational linear speed (that is, process speed) of the developing sleeve 44 during image formation and the wear rate α (FIG. 11) (S102). Next, the toner concentration is detected by the toner concentration sensor 45 (S103), and the toner concentration is averaged (S104). Then, the CPU 206 obtains the toner density correction coefficient β(m) from the table (FIG. 12) of the average toner density calculated by the averaging process and the toner density correction coefficient β (S105).

Next, the CPU 206 uses Δt, α, and β acquired up to S105 to calculate the amount of wear Δd(m) of the regulating blade 42 using the above equation (3) (S106). Next, the total wear amount d(m) is updated by adding the wear amount Δd(m) of the m-th sheet to the total wear amount d(m-1) of the m-1th sheet (S107). The CPU 206 calculates the life L(m) of the developing device based on the total wear amount d(m) and the threshold value _d1 (S108), and displays it on the display unit 220 or notifies the server through the notification unit 800 (S109). Further, the CPU 206 determines whether the life L (m) of the developing device calculated in S108 is less than a predetermined value Lth (S110). If the lifespan L(m) is greater than or equal to the predetermined value Lth (N in S110), the CPU 206 displays a replacement message on the display unit 220 or sends a replacement notification to the server using the notification unit 800 (S111).

In this embodiment, if the traveling distance of the developing sleeve 44 is the same and the toner concentration detected by the toner concentration sensor 45 is constant, the display section 220 will display the following information depending on the toner concentration. display. First, the CPU 206 displays the developing device replacement message on the display unit 220 later when the toner density is higher than the first density than when the toner density is the first density. . Similarly, the CPU 206 sets the life L (m ) is displayed.

[Effects of this embodiment]
Next, the effects of this embodiment will be described using Example 1 and a comparative example that satisfy the configuration of this embodiment. In Example 1, images with an image ratio of 5% are continuously formed under the image forming conditions of 30° C. and 80% high humidity. In a high humidity environment, the toner concentration was controlled at 7% in order to maintain a constant charge amount of the toner. On the other hand, as a comparative example, the predicted wear amount of the regulation blade 42 in the case where the wear rate is not corrected based on the toner concentration is shown. In the comparative example, when an image was formed under the same conditions as in Example 1, the amount of wear of the regulating blade 42 was predicted from the running time of the developing sleeve 44 with a toner concentration of 9%.

FIG. 15 shows the relationship between the amount of wear of the regulating blade 42 and the number of images formed under such image forming conditions. The black circles in FIG. 15 indicate the amount of wear on the regulation blade 42 that was actually measured, the solid line indicates the amount of wear on the regulation blade 42 predicted by the comparative example, and the broken line indicates the amount of wear on the regulation blade 42 predicted according to Example 1.

As shown in FIG. 15, when an image is formed with a toner concentration of 7%, the amount of wear on the regulating blade 42 increases. On the other hand, the amount of wear in the comparative example calculated based on the running time of the developing sleeve 44 without considering the toner concentration gradually deviates from the actually measured amount of wear (black circles in FIG. 15) as image formation progresses. ing. Therefore, in the comparative example, it can be seen that the accuracy of wear amount prediction is low depending on the usage environment of the user. On the other hand, in Example 1, since the amount of wear is predicted in consideration of the toner concentration, the deviation from the amount of actually measured wear is small and the prediction accuracy is high.

FIG. 16 shows the life transition of the developing device based on the amount of wear shown in FIG. 15. Further, the lifespan of the developing device can be confirmed in units of 1% on the display section 220. According to FIG. 16, the actual life of the developing device is reached after approximately 500,000 sheets, whereas in the comparative example, the life of the developing device is displayed as 75%. As a result, there is a possibility that image defects may occur even though the displayed life of the developing device has not reached 100%. On the other hand, in Example 1, the accuracy of predicting the amount of wear of the regulating blade 42 was high, so it was found that the life of the developing device could be predicted more accurately than in the comparative example.

As described above, in this embodiment, by predicting the amount of wear of the regulation blade 42 in consideration of the toner concentration, the replacement life of the developing device due to the wear of the regulation blade 42 can be predicted with high accuracy.

<Second embodiment>
The second embodiment will be described using FIGS. 17 to 24 while referring to FIGS. 1 to 6 and 10. In the first embodiment described above, the amount of wear of the regulating blade 42 is corrected using the toner concentration as the developer characteristic. On the other hand, in this embodiment, the amount of wear of the regulating blade 42 is corrected using the toner deterioration index as a characteristic of the developer. Other configurations and operations are the same as those in the first embodiment, so the same configurations are given the same reference numerals and explanations and illustrations will be omitted or simplified, and the points different from the first embodiment will be described below. I will mainly explain.

First, FIG. 17 shows the relationship between the image ratio and the wear amount ratio of the regulating blade. The wear amount ratio of the regulating blade is defined as the wear amount of the regulating blade 42 when an image is formed at a predetermined image ratio, and the wear amount of the regulating blade when an image is formed at an image ratio different from the predetermined image ratio. It is the ratio of the amount of wear of No. 42 to the reference amount of wear. The standard wear amount is the wear amount of the regulation blade 42 when continuous image formation is performed at an image ratio of 5% under the conditions that the amount of developer in the developing device (inside the developer container 41) is 200 g and the toner concentration of the developer is 9%. . According to the inventor's study, when continuous images are formed at an image ratio of 5% and an image ratio of 40% under the conditions of a developer amount of 200 g and a toner concentration of 9%, the image ratio of 40% is approximately 1.2 times larger. It was found that the amount of wear on the regulation blade was large. However, this is not the case because the regulated blade wear ratio changes depending on the type and amount of external additives added.

If images with a low image ratio continue, the toner remains in the developing device for a long time, causing toner deterioration in which external additives are separated from the toner or embedded in the toner surface. Therefore, as toner deterioration progresses, the coverage rate of the external additive to the toner decreases. Since the external additive has a higher hardness than the toner, the regulation blade 42 is less likely to wear out as the toner deteriorates. Therefore, the lower the image ratio, the less the amount of wear on the regulating blade 42.

Therefore, in this embodiment, toner deterioration is defined as the average time that the toner in the developing device stays in the developing device by repeating replenishment and consumption, and the toner deterioration index T_index, which is an index thereof, is defined by the following formula. do.
T_index(m)={T_index(m-1)+Δt(m)}×Mt(m)/{Mt(m)+mt(m)}...(6)

Here, Δt (m): Drive time (s) of the development drive motor in calculation interval m
Mt(m): Amount of toner in the developing device in calculation interval m mt(m): Replenishment amount in calculation interval m.

The amount Mt of toner in the developing device is 18 g when the toner concentration is 9%, assuming that the design center value of the amount of developer in the developing device is 200 g. For the replenishment amount mt(m) in the calculation interval m, the predicted toner consumption amount Tv (first replenishment amount) predicted according to the video count is used, but the rotation time of the replenishment developer storage container 8, etc. I do not care. Alternatively, T=Tv−Ttd (formula (2) above) may be used, which takes into account the toner replenishment amount Ttd (second replenishment amount) in the inductance method.

FIG. 18 shows the transition of the toner deterioration index T_index when an image is formed with a developer amount of 200 g, a toner concentration of 9%, and an image ratio of 5% and 40%. The lower the image ratio, the slower the replacement of toner due to consumption and replenishment, so the toner deterioration index indicating the average residence time in the developing device is large. FIG. 19 shows the image ratio and the saturation value of the toner deterioration index (saturated toner deterioration index) at that image ratio under the above conditions.

In this embodiment, the wear amount Δd(m) of the m-th regulation blade 42 is defined as follows from the Ratner's wear formula described above.
Δd(m)=Δt(m)×α(m)×β′(m)...(7)

Here, Δd (m): Amount of wear in calculation interval m (μm)
Δt (m): Drive time of development drive motor (s)
α(m): Wear rate proportional to the rotational linear speed of the developing sleeve β'(m): Correction coefficient according to the toner deterioration index.

α(m) is the amount of wear per unit time (wear rate) that is proportional to the rotational linear speed of the developing sleeve, as in the first embodiment. Further, β'(m) is a correction coefficient according to the toner deterioration index T_index. As described above, as the toner deteriorates, the coverage ratio of the external additive to the toner changes, so the wear rate changes. As described above, the toner deterioration index has a correlation with the image ratio. Therefore, in this embodiment, as described above, the amount of wear of the regulating blade 42 according to the traveling distance of the developing sleeve 44 is corrected according to the image ratio (specifically, the toner deterioration index).

FIG. 20 shows a table showing the relationship between the toner deterioration index and the correction coefficient β'. Based on a toner concentration of 9%, the correction coefficient β' is changed according to the toner deterioration index. As is clear from FIG. 20, the larger the toner deterioration index is, the smaller the coverage of the external additive is, so the regulating blade 42 is less likely to wear out, and the smaller the toner deterioration index is, the more easily the regulating blade 42 is worn out. In the table of FIG. 20, linear interpolation is performed between the tables.

Here, with reference to FIG. 10, a circuit block diagram for predicting the wear amount of the regulating blade 42 and determining the lifespan of the developing device in this embodiment will be described. In this embodiment, in addition to the configuration of the first embodiment, a video signal counting section 207, a replenishment amount calculating section 214, and a toner deterioration index calculating section 215 are used to calculate the wear amount of the regulation blade.

The replenishment amount calculating section 214 calculates the replenishment amount mt(m) in the calculation interval m based on the video count value calculated by the video signal counting section 207. The replenishment amount mt(m) is assumed to be the predicted toner consumption amount Tv (first replenishment amount). The toner deterioration index calculation unit 215 calculates the toner based on the driving time Δt(m) of the developing drive motor, the amount of toner in the developing device Mt(m), and the amount of replenishment mt(m) using the above equation (6). Calculate the deterioration index T_index (m).

The wear amount calculation unit 216 calculates the wear amount d(m) of the regulating blade 42 using the above-mentioned equation (7), and calculates the wear amount d(m) of the regulating blade 42 by the drive time Δt(m) of the developing drive motor and the wear rate proportional to the rotational linear speed of the developing sleeve. It is calculated based on α(m) and a correction coefficient β'(m) according to the toner deterioration index. Similar to the first embodiment, the developing device life calculating section 217 calculates the developing device life L based on the total wear amount d(m) calculated by the wear amount calculating section 216 (Equation (4), (See (5)).

Similarly to the first embodiment, the CPU 206 displays the life L of the developing device calculated by the developing device life calculating unit 217 on the display unit 220 serving as a display means to notify the user. The life L of the developing device is notified to the user in 1% increments, and is counted up as the life of the developing device progresses. Then, when the life L of the developing device reaches a predetermined value Lth, a message prompting the user to replace the developing device is displayed on the display unit 220. Furthermore, the CPU 206 uses the notification unit 800 to notify the serviceman of the current lifespan L of the developing device via the server at a predetermined timing, and urges the serviceman to replace service parts systematically. Then, when the life L of the developing device reaches a predetermined value Lth, the notification unit 800 notifies the server of replacement and prompts the service person to replace the part.

[Flow of calculating the lifespan of the developing device]
FIG. 21 shows a flowchart for calculating the life of the developing device in this embodiment. The flow other than the flow for calculating the toner deterioration index correction coefficient β'(m) is the same as that of the first embodiment shown in FIG. 14, so the description thereof will be omitted. That is, S201 to S203 in FIG. 21 correspond to S101 to S103 in FIG. 14, respectively, and S209 to S213 in FIG. 21 correspond to S107 to S111 in FIG. 14, respectively.

In this embodiment, the CPU 206 obtains the video count of each image after S203 (S204). Then, the CPU 206 calculates the first replenishment amount Tv(m) using the replenishment amount calculation unit 214 (S205). The CPU 206 calculates the toner deterioration index T_index(m) using equation (6) based on the information obtained in S201, S203, and S205 (S206). Then, the CPU 206 obtains the toner deterioration index correction coefficient β'(m) from the table of toner deterioration index and correction coefficient β' shown in FIG. 21 (S207). Next, the CPU 206 calculates the amount of wear Δd(m) of the regulating blade 42 using the above equation (7) using Δt, α, and β′ acquired up to S207 (S208). Thereafter, the flow of calculating the total wear amount d(m) and the lifespan L(m) of the developing device, displaying the information on the display unit 220, and notifying the server is the same as in the first embodiment. .

In the case of this embodiment, if the traveling distance of the developing sleeve 44 is the same and the image ratio is constant, the display section 220 performs the following display according to the image ratio. First, the CPU 206 displays a developing device replacement message on the display unit 220 more quickly when the image ratio is at the second ratio, which is higher than the first ratio, than when the image ratio is at the first ratio. . Similarly, the CPU 206 sets the life L (m ) is displayed.

[Effects of this embodiment]
Next, the effects of this embodiment will be described using Example 2 and a comparative example that satisfy the configuration of this embodiment. In Example 2, the regulations apply when 10 images with an image ratio of 40% and images with an image ratio of 5% are alternately formed on 10 sheets under the conditions that the amount of developer in the developing device is 200 g and the toner concentration of the developer is 9%. The operation of predicting the amount of blade wear will be explained. However, as an initial condition, the toner deterioration index is set to 190 (see FIG. 19, the saturated toner deterioration index when the image ratio is 40%). As comparative examples, Comparative Example 1 is a case in which toner deterioration index correction coefficient β' is not performed (that is, toner deterioration index correction coefficient β' = 1), and a case in which toner deterioration index correction coefficient β' is changed by image ratio (table in FIG. 17). This is shown as Comparative Example 2. In Comparative Examples 1 and 2, image formation was also performed under the same conditions as in Example 2.

FIG. 22 shows changes in image ratio and toner deterioration index T_index (m) under such image forming conditions. As shown in FIG. 22, the toner deterioration index gradually increases from the saturated toner deterioration index when the image ratio is 40%, which is the initial condition. In Example 2, the toner deterioration index gradually changes as the image ratio is switched, whereas in the case of the correction in Comparative Example 2, when the image ratio is switched, the toner deterioration index changes to the saturated toner deterioration index for each image ratio. This means instant switching.

FIG. 23 shows the change in the correction coefficient β'(m) when an image is formed under the above conditions. The solid line is the change in the correction coefficient β' of Comparative Example 1, the broken line is Comparative Example 2, and the dotted line is Example 2. In Comparative Example 1, the correction coefficient β'=1 regardless of the image ratio. In Comparative Example 2, the correction coefficient β' is changed for each image ratio. That is, according to FIG. 17, β'=1.2 when the image ratio is 40%, and β'=1 when the image ratio is 5%. On the other hand, in the second embodiment, the correction coefficient β' is changed depending on the toner deterioration index. Therefore, the correction coefficient β' in Example 2 gradually changes as the image ratio is switched.

FIG. 24 shows the life transition of the developing device under the above conditions. The black circles in FIG. 24 indicate the life of the developing device based on the actually measured wear amount of the regulation blade, the solid line indicates the life of the developing device predicted by Comparative Example 1, and the broken line indicates the life of the developing device predicted by Comparative Example 2. The dotted line is the life expectancy of the developing device predicted by Example 2.

As shown in FIG. 24, when forming an image by switching the image ratio, Comparative Example 1 (correction coefficient β' = 1), which is calculated based on the running time of the developing sleeve, has low accuracy in predicting the amount of wear depending on the user's usage environment. , it can be seen that the accuracy of predicting the life of the developing device is low. Furthermore, it can be seen that Comparative Example 2, in which the correction coefficient β' is changed according to the image ratio, has higher accuracy in predicting the life of the developing device than Comparative Example 1. Furthermore, it can be seen that Example 2, in which the correction coefficient β' was changed according to the toner deterioration index, has higher accuracy in predicting the life of the developing device than Comparative Example 2.

As described above, in this embodiment, by predicting the amount of wear of the regulation blade 42 in consideration of the image ratio, it is possible to accurately predict the replacement life of the developing device due to wear of the regulation blade 42. Further, when the toner deterioration index is used, the replacement life of the developing device can be predicted with even higher accuracy.

Note that when using the toner deterioration index, as explained in equation (6) above, when calculating the toner amount Mt (m) in the developing device, the toner concentration is set to the design central value of the developing device in the developing device. is multiplied by Therefore, it can be said that the life prediction of the developing device using the toner deterioration index is based on the toner concentration in addition to the image ratio.

Further, although FIG. 20 shows the toner deterioration index and correction coefficient β' based on a toner concentration of 9%, it is also possible to have a table of toner deterioration index and correction coefficient β' for each of a plurality of toner concentrations. good. In this case, the lifetime prediction of the developing device using the toner deterioration index is performed based on the toner density in addition to the image ratio.

<Third embodiment>
The third embodiment will be described using FIGS. 25 to 29 while referring to FIGS. 1 to 6, FIG. 10, and FIGS. 17 to 20. In the first and second embodiments described above, α(m) is a wear rate proportional to the rotational linear speed of the developing sleeve, and the regulating blade 42 is adjusted using a wear rate that changes linearly with the rotational linear speed of the developing sleeve. Corrected the amount of wear. On the other hand, in this embodiment, the amount of wear of the regulating blade 42 is corrected using the wear rate α'(m) that changes non-linearly with respect to the rotational linear speed of the developing sleeve. Other configurations and operations are the same as those in the second embodiment, so the same configurations will be given the same reference numerals and explanations and illustrations will be omitted or simplified, and the points different from the second embodiment will be described below. I will mainly explain.

When the rotational linear speed (peripheral speed) of the developing sleeve 44 is constant, the amount of wear on the regulating blade 42 is the product of the wear rate α (m), which is proportional to the rotational linear speed of the developing sleeve 44, and the driving time (rotation time) t. proportional to a certain distance traveled. However, if there are multiple circumferential speeds at which the developing sleeve 44 is driven, an error may occur in the amount of wear of the regulating blade 42. This is because the speed of the developer passing near the regulating blade 42 (that is, the amount of developer passing near the blade and causing wear) changes non-linearly depending on the circumferential speed of the developing sleeve 44. Since the amount of wear occurs as the developer passes, it is desirable to correct the amount of wear depending on the amount (and passing speed) of the developer near the blade.

Therefore, in this embodiment, the amount of wear is corrected based on the developer speed and drive time, which vary depending on the rotational linear speed of the developing sleeve 44. In this embodiment, the configuration other than the wear rate is the same as that of the second embodiment.

FIGS. 25 and 26 show the relationship between the wear rate α' (m) and the rotation linear speed (sleeve peripheral speed) of the developing sleeve 44. This wear rate is based on the amount of wear of the regulating blade 42 when images are formed continuously at an image ratio of 5% under conditions of a developer amount of 200 g in the developing device and a toner concentration of 9%, and images are formed at each sleeve circumferential speed. Calculated from the wear amount data when This is the same relationship as the ratio of the speed of the developer near the blade to the circumferential speed of the sleeve. This is because as the sleeve circumferential speed increases, the speed ratio of the developer to the sleeve circumferential speed decreases, so the slope of the wear rate α'(m) becomes smaller. However, since the speed of the developer conveyed to the developing sleeve changes depending on the shape of the sleeve, the magnetic force of the magnet roll 44a near the blade portion, the carrier, etc., the shape of this graph of the amount of wear changes. Furthermore, the amount of wear on the regulating blade changes depending on the type and amount of external additives added to the toner.

In this embodiment, the wear amount Δd(m) of the m-th regulation blade 42 is defined as follows from the Ratner's wear formula described above.
Δd (m) = Δt (m) × α' (m) × β' (m) ... (8)

Here, Δd (m): Amount of wear in calculation interval m (μm)
Δt (m): Drive time of development drive motor (s)
α'(m): Wear rate according to the rotational linear speed of the developing sleeve β'(m): Correction coefficient according to the toner deterioration index.

α'(m) is the amount of wear per unit time (wear rate) depending on the rotational linear speed of the developing sleeve. Further, β'(m) is a correction coefficient according to the toner deterioration index T_index, as in the second embodiment. As described in the second embodiment, the coverage rate of the external additive to the toner changes due to toner deterioration, so the wear rate changes. In this embodiment, images will be continuously formed at an image ratio of 5%, and the wear rate in a region where the toner deterioration index T_index is stable will be described. As described in the second embodiment, FIGS. 19 and 20 are tables showing the relationship between the toner deterioration index and the correction coefficient β'. In this embodiment, since an image is formed with a toner density of 9% and an image ratio of 5%, β' is calculated as 1.

Here, with reference to FIG. 10, a circuit block diagram for predicting the wear amount of the regulating blade 42 and determining the lifespan of the developing device in this embodiment will be described. In this embodiment as well, in addition to the configuration of the first embodiment, the amount of wear of the regulating blade is calculated using a video signal counting section 207, a replenishment amount calculating section 214, and a toner deterioration index calculating section 215.

In the case of the present embodiment, as in the second embodiment, the replenishment amount calculating section 214 calculates the replenishment amount mt(m) in the calculation interval m based on the video count value calculated by the video signal counting section 207. calculate. The replenishment amount mt(m) is assumed to be the predicted toner consumption amount Tv (first replenishment amount). The toner deterioration index calculation unit 215 calculates the toner based on the driving time Δt(m) of the developing drive motor, the amount of toner in the developing device Mt(m), and the amount of replenishment mt(m) using the above equation (6). Calculate the deterioration index T_index (m).

The wear amount calculation unit 216 calculates the wear amount d(m) of the regulating blade 42 using the above-mentioned formula (8), and calculates the wear amount d(m) of the regulating blade 42 from the wear rate according to the driving time Δt(m) of the developing drive motor and the rotational linear speed of the developing sleeve. It is calculated based on α'(m) and a correction coefficient β'(m) according to the toner deterioration index. Similar to the first embodiment, the developing device life calculating section 217 calculates the developing device life L based on the total wear amount d(m) calculated by the wear amount calculating section 216 (Equation (4), (See (5)).

[Flow of calculating the lifespan of the developing device]
FIG. 27 shows a flowchart for calculating the life of the developing device in this embodiment. This embodiment is the same as the second embodiment except that α'(m) is used as the wear rate. That is, in this embodiment, when images are formed at different process speeds, the wear rate α'(m) is used depending on the developer speed.

When the developing device life prediction is started, the CPU 206 acquires the developing drive time Δt(m) for each image formation (S301). Next, the wear rate α' (m) is obtained from the table (FIG. 25) of the rotational linear speed of the developing sleeve during image formation and the wear rate α' (S302). Next, the toner density is detected and averaging processing is performed (S303). In S304, the video count of each image is acquired. Then, the first supply amount Tv(m) is calculated (S305). A toner deterioration index T_index (m) is calculated based on the information obtained in S301, S303, and S305 (S306). Then, the toner deterioration index correction coefficient β'(m) is obtained from the table of toner deterioration index and correction coefficient β' shown in FIG. 20 (S307).

Then, the amount of wear Δd(m) is calculated using Δt, α', and β' acquired up to S307 (S308). In S309, the total wear amount d(m) is updated by adding the m-th sheet wear amount Δd(m) to the m-1 sheet total wear amount d(m-1). The lifespan L(m) of the developing device is calculated based on the threshold value _dl (S310), and is displayed on the display unit 220 or notified to the server (S311). Further, in S312, it is determined whether the life L (m) of the developing device is less than a predetermined value Lth. If the value is greater than or equal to the predetermined value (N at S312), an exchange message is displayed on the display unit 220 or an exchange notification is sent to the server (S313). As described above, in the case of the present embodiment, the replacement message and lifespan of the developing device are displayed on the display unit 220 or sent to the server based on the rotational linear speed of the developing sleeve 44.

[Effects of this embodiment]
Next, the effects of this embodiment will be described using Example 3 and a comparative example that satisfy the configuration of this embodiment. Embodiment 3 describes the operation of predicting the amount of wear of the regulation blade 42 when images with an image ratio of 5% are continuously formed under the conditions that the amount of developer in the developing device is 200 g and the toner concentration of the developer is 9%. do. Two circumferential speeds of the developing sleeve 44 are compared: 270 mm/s (PS 150 mm/s) and 540 mm/s (PS 300 mm/s). Note that "PS" is a process speed, and corresponds to the rotational linear speed of the photosensitive drum in FIG. 25.

When the circumferential speed of the developing sleeve 44 is 270 mm/s (PS 150 mm/s), α (m): a wear rate proportional to the rotational linear speed of the developing sleeve, and α′ (m): a wear rate according to the developer speed. are the same. Therefore, the relationship between the amount of wear and the number of images formed is the same as in the comparative example shown in FIG.

FIG. 28 shows the relationship between the amount of wear of the regulating blade 42 and the number of images formed when images are formed at a circumferential speed of the developing sleeve 44 of 540 mm/s (PS 300 mm/s). The black circle in FIG. 28 is the amount of wear of the regulating blade 42 actually measured at a circumferential speed of the developing sleeve 44 of 540 mm/s. The solid line is the case predicted from the wear rate α proportional to the rotational linear speed of the developing sleeve 44 (Comparative Example 3), and the broken line is the amount of wear of the regulation blade 42 predicted according to Example 3.

As shown in FIG. 28, when an image is formed with a toner concentration of 7%, the amount of wear on the regulating blade 42 increases. It can be seen that Comparative Example 3, which was predicted from the wear rate α proportional to the rotational linear speed of the developing sleeve 44, had lower accuracy in predicting the amount of wear than Example 3.

FIG. 29 shows the life transition of the developing device based on the amount of wear shown in FIG. 28. According to FIG. 29, the actual life of the developing device is reached at approximately 734,100 sheets, whereas in Comparative Example 3, the life of the developing device is displayed as 100% at 666,600 sheets. As a result, the lifespan of the developing device reaches 100% earlier than its actual lifespan, resulting in an increase in costs associated with maintenance. In Example 3, the prediction accuracy for the amount of wear of the regulating blade 42 is high, so that the life of the developing device can be predicted with higher accuracy than in Comparative Example 3.

As described above, in this embodiment, by predicting the amount of wear of the regulating blade 42 using the wear rate α' corresponding to the developer speed, the replacement life of the developing device due to the wear of the regulating blade 42 can be accurately predicted. Note that in this embodiment, the wear rate α is set to α' in the configuration of the second embodiment, but the wear rate α may be set to α' in the first embodiment.

<Fourth embodiment>
The fourth embodiment will be described using FIGS. 30 and 31 while referring to FIGS. 1 to 6 and 10. In the first embodiment described above, the amount of wear of the regulating blade 42 is corrected using the toner concentration as the developer characteristic. On the other hand, in this embodiment, the amount of wear of the regulating blade 42 is corrected by taking into account the magnetic force of the magnet roll 44a included in the developing sleeve 44. Other configurations and operations are the same as those in the first embodiment, so the same configurations are given the same reference numerals and explanations and illustrations will be omitted or simplified, and the points different from the first embodiment will be described below. I will mainly explain.

There are manufacturing variations in the magnet roll 44a included in the developing sleeve 44, resulting in differences in magnetic flux density and magnetic pole position. In particular, among the plurality of magnetic poles of the magnet roll 44a, variations in the layer thickness regulating magnetic pole N1 at the position facing the regulating blade 42 affect the magnitude of the magnetic force Fr_b at the tip position of the regulating blade 42, depends largely on wear rate.

Therefore, in this embodiment, the amount of wear Δd(m) of the m-th regulation blade 42 is defined as follows from the above-mentioned Ratner's wear equation, taking into account the variation in the magnetic force Fr.
Δd(m)=Δt(m)×α(m)×β(m)×γ(m)...(9)

Here, Δd (m): Amount of wear in calculation interval m (μm)
Δt (m): Drive time of development drive motor (s)
α (m): Wear rate proportional to the rotational linear speed of the developing sleeve β (m): Correction coefficient according to the toner concentration of the developer γ (m): Magnetic force correction coefficient according to Fr_b at the tip of the regulation blade be.

FIG. 30 shows the relationship between variations in the layer thickness regulating magnetic pole N1 of the developing sleeve 44 and the magnetic force Fr around the regulating blade 42. The magnetic force Fr increases or decreases depending on the upper and lower limits of manufacturing variations in the magnetic flux density of the layer thickness regulating magnetic pole N1, and the position where the layer thickness regulating magnetic pole N1 faces the regulating blade 42 changes due to variations in the magnetic pole position. Therefore, as shown in FIG. 30, the magnetic force Fr_b at the tip position of the regulating blade 42 is up to Fr_max at the maximum and Fr_min at the minimum with respect to the position of the center of the layer thickness regulating magnetic pole N1 and the magnetic force Fr_m at the center of the magnetic flux density. It varies. In this embodiment, the magnetic flux density of the layer thickness regulating magnetic pole N1 was 65 mT±5 mT, and the magnetic pole position (angle) was ±3 degrees from the opposing position of the regulating blade 42. At this time,
Fr_max=1.33×Fr_m
Fr_min=0.72×Fr_m
It became.

The larger the magnetic force Fr_b at the tip of the regulating blade 42 is, the greater the sliding friction between the regulating blade 42 and the developer becomes, and the wear of the regulating blade 42 progresses. Therefore, Fr_b at the tip of the regulating blade 42, that is, the magnetic force correction coefficient correction coefficient γ corresponding to the magnetic force at the tip position of the regulating blade 22 facing the developing sleeve 44 is as follows.
γ(m)=Fr_b/Fr_m...(10)

The magnetic flux density data of the developing sleeve 44 unique to the developing device is measured in the manufacturing process of the developing device 4, and the magnetic force Fr_b is calculated from the measurement result to determine the magnetic force correction coefficient γ(m). The number assigned to each magnetic force correction coefficient γ(m) is written on the developing device 4 together with the Lot number of the developing device 4. When the developing device 4 is installed in the image forming apparatus 100, the number written for each of the image forming units PY, PM, PC, and PK is input from the display unit 220 such as an operation panel.

Note that, as shown in FIG. 10, in addition to the configuration of the first embodiment, the image forming apparatus 100 may include a developing device memory tag 900 and a communication unit 901. The developing device memory tag 900 is provided in the developing device 4, and stores at least one of the above-mentioned magnetic flux density data, magnetic force Fr_b, and magnetic force correction coefficient γ(m). The communication unit 901 is provided in the apparatus main body 101 of the image forming apparatus 100, communicates with the developing device memory tag 900 of the developing device 4 attached to the apparatus main body 101, and reads data from the developing device memory tag 900. If the read data is the magnetic force correction coefficient γ(m), the CPU 206 uses this in the calculation using the above equation (9), and if the data is other than that, it uses the above equation (10) to calculate the read data. Calculate the magnetic force correction coefficient γ (m).

[Flow of calculating the lifespan of the developing device]
FIG. 31 shows a flowchart for calculating the life of the developing device in this embodiment. This embodiment is the same as the first embodiment except that the magnetic force correction coefficient γ(m) is used. First, S401 to S405 are the same as S101 to S105 in FIG. 14 of the first embodiment. After S405, the CPU 206 obtains the magnetic force correction coefficient γ(m) according to Fr_b from the information input when installing the developing device (S406). Then, the CPU 206 calculates the wear amount Δd(m) using Δt, α, β, and γ acquired up to S406 (S407).

Next, the total wear amount d(m) is updated by adding the wear amount Δd(m) of the m-th sheet to the total wear amount d(m-1) of the m-1th sheet (S408). The CPU 206 calculates the life L(m) of the developing device based on the total wear amount d(m) and the threshold value _d1 (S409), and displays it on the display unit 220 or notifies the server through the notification unit 800 (S410). Further, the CPU 206 determines whether the life L (m) of the developing device calculated in S409 is less than a predetermined value Lth (S411). If the lifespan L(m) is greater than or equal to the predetermined value Lth (N in S411), the CPU 206 displays a replacement message on the display unit 220 or sends a replacement notification to the server using the notification unit 800 (S412).

In this embodiment, the amount of wear of the regulation blade 42 is predicted by considering the magnetic force Fr_b at the tip position of the regulation blade 22 facing the developing sleeve 44, thereby preventing replacement of the developing device due to wear of the regulation blade 42. Lifespan can be predicted with high accuracy. In addition, in this embodiment, in addition to the configuration of the first embodiment, the amount of wear of the regulating blade 42 is predicted by considering the magnetic force Fr_b. However, in addition to the configurations of the second embodiment and the third embodiment, the amount of wear of the regulating blade 42 is predicted by considering the magnetic force Fr_b, and a message for replacing the developing device and the lifespan are displayed. Also good.

<Fifth embodiment>
The fifth embodiment will be described using FIGS. 32 to 37 while referring to FIGS. 1 to 6, FIG. 10, FIG. 30, and FIG. 31. In the fourth embodiment described above, the amount of wear of the regulating blade 42 is corrected in consideration of the magnetic force of the magnet roll 44a included in the developing sleeve 44. On the other hand, in this embodiment, the amount of wear of the regulating blade 42 is corrected in consideration of a predetermined gap (gap amount) between the developing sleeve 44 and the regulating blade 42. Other configurations and operations are the same as those in the first and fourth embodiments, so the same configurations are designated by the same reference numerals and explanations and illustrations are omitted or simplified. The explanation will focus on the points that are different from the embodiment.

In this embodiment, the amount of wear d(m) is corrected according to the size of a predetermined gap (gap amount) between the developing sleeve 44 and the regulating blade 42 of the developing device 4, and _dl , which is the life threshold of the developing device 4, is corrected. make a decision The gap between the developing sleeve 44 and the regulating blade 42 varies, for example, from 270 to 330 μm from developing device to developing device due to manufacturing variations.

Here, the gap amount D (m) is calculated as follows.
Gap amount D (m) = D (m-1) + Δd (m) ... (11)

Note that Δd(m) used to calculate the gap amount D(m) is calculated using equation (9) in the above-mentioned fourth embodiment. Further, when m=1, the gap amount D(1)=D(0)+Δd(m) is obtained, and this D(0) is the difference between the developing sleeve 44 and the regulating blade 42 at the time of manufacturing the developing device 4. This is the predetermined gap (initial gap amount) between. As will be described later, the initial gap amount D(0) is measured at the time of manufacturing the developing device 4, and is acquired by the CPU 206 when the developing device 4 is attached (installed) to the device main body 101 of the image forming device 100. It is something.

FIG. 32 is a table showing the relationship between the gap amount D(m) between the developing sleeve 44 and the regulating blade 44 and the gap correction coefficient σ(m). As the gap becomes narrower, the pressure of the developer between the developing sleeve 44 and the regulating blade 42 increases, the sliding friction between the regulating blade 42 and the developer increases, and the amount of wear of the regulating blade 42 increases. In the table of FIG. 32, linear interpolation is performed between the tables.

In this embodiment, considering the variation in the amount of gap between the developing sleeve 44 and the regulating blade 42 during manufacturing of the developing device 4, the amount of wear of the regulating blade 42 at the m-th sheet is calculated from the Ratner's wear formula described above. Δd(m) is defined as follows.
Δd(m)=Δt(m)×α(m)×β(m)×γ(m)×σ(m)...(12)

Here, Δd (m): Amount of wear in calculation interval m (μm)
Δt (m): Drive time of development drive motor (s)
α (m): Wear rate proportional to the rotational linear speed of the developing sleeve β (m): Correction coefficient according to the toner concentration of the developer γ (m): Magnetic force correction coefficient according to Fr_b at the tip of the regulating blade σ (m): Gap correction coefficient according to the gap between the developing sleeve 44 and the regulating blade 42.

Next, calculation of _d1 , which is the life threshold in this embodiment, will be explained. FIG. 33 shows the relationship between the gap D (m) between the developing sleeve 44 and the regulating blade 44, the amount of developer coating (layer thickness), and the amount of wear d. When the gap D (m) is narrow, the developer coating amount is small, so the wear threshold d ₁ reaches the coating amount threshold at which a fogged image occurs due to developer retention upstream of the regulating blade 42 in the rotational direction of the developing sleeve 44. becomes larger.

FIG. 34 shows the relationship between the initial gap amount D(0) and the wear threshold value _d1 calculated from this relationship. The gap between the developing sleeve 44 and the regulating blade 42 is determined by photographing the gap with a camera during manufacturing of the developing device 4, performing image judgment on the edges of the developing sleeve 44 and regulating blade 42, and measuring the difference between the edges. The measured initial gap amount D(0) is written on the developing device 4 together with the Lot number, and when the developing device 4 is installed in the image forming apparatus 100, it is displayed on each image forming unit from the display unit 220 such as an operation panel. Enter the numbers written for each of PY, PM, PC, and PK.

In the case of this embodiment as well, as shown in FIG. 10, in addition to the configuration of the first embodiment, the image forming apparatus 100 may include a developing device memory tag 900 and a communication unit 901. The developing device memory tag 900 is provided in the developing device 4, and stores the above-mentioned initial gap amount D(0). The communication unit 901 is provided in the apparatus main body 101 of the image forming apparatus 100, communicates with the developing device memory tag 900 of the developing device 4 attached to the apparatus main body 101, and reads data from the developing device memory tag 900.

[Flow of calculating the lifespan of the developing device]
FIG. 35 shows a flowchart for calculating the life of the developing device in this embodiment. This embodiment is the same as the fourth embodiment except that the gap force correction coefficient σ(m) is used and the wear threshold value _d1 is obtained from the initial gap amount D(0). First, S501 to S506 are the same as S401 to S406 in FIG. 31 of the fourth embodiment. After S506, the CPU 206 calculates the gap amount D(m) using the above equation (11) (S507). At this time, the CPU 206 uses Δt, α, β, and γ acquired up to S506 to calculate the wear amount Δd(m) using equation (9) of the fourth embodiment. Further, when calculating D(m), the initial gap amount D(0) is obtained from information inputted at the time of installing the developing device.

Next, the CPU 206 obtains the gap correction coefficient σ(m) from the table (FIG. 32) of the gap amount D(m) and the gap correction coefficient σ(m) (S508). Then, using Δt, α, β, γ, and σ obtained up to S508, the wear amount Δd(m) is calculated again using the above equation (12) (S509).

Next, the total wear amount d(m) is updated by adding the wear amount Δd(m) of the m-th sheet to the total wear amount d(m-1) of the m-1th sheet (S510). Further, the CPU 206 obtains the wear threshold value d ₁ from the initial gap amount D(0) using the table of FIG. 34 (S511). Then, the CPU 206 calculates the life L (m) of the developing device based on the total wear amount d (m) and the wear threshold value _d1 (S512), and displays it on the display unit 220 or notifies the server through the notification unit 800 ( S513). Further, the CPU 206 determines whether the life L (m) of the developing device calculated in S512 is less than a predetermined value Lth (S514). If the lifespan L(m) is greater than or equal to the predetermined value Lth (N in S514), the CPU 206 displays a replacement message on the display unit 220 or sends a replacement notification to the server using the notification unit 800 (S515).

[Effects of this embodiment]
Next, the effects of this embodiment will be described using Examples 4 and 5 and a comparative example that satisfy the configuration of this embodiment. In Examples 4 and 5, images with an image ratio of 5% are continuously formed under the image forming conditions of 30° C. and 80% high humidity. In Examples 4 and 5, the magnetic flux density of the layer thickness regulating magnetic pole N1 was large and Fr_b=1.2×Fr_m, that is, the magnetic force correction coefficient γ(m)=1.2. Further, Examples 4 and 5 were prepared in which the initial gap amount D(0) was 300 μm (Example 4) and 280 μm (Example 5), respectively. Further, the rotational linear speed of the developing sleeve 44 was fixed at 540 mm/s, the toner concentration was fixed at 9%, and the coefficients α(m) and β(m) were the same. On the other hand, as Comparative Example 4, the predicted wear amount of the regulating blade 42 in the case where the wear rate is not corrected by the magnetic force and the gap amount is shown. In Comparative Example 4, when images were formed under the same conditions as Examples 4 and 5, the amount of wear of the regulating blade 42 was predicted from the running time of the developing sleeve 44 with a toner concentration of 9%.

FIG. 36 shows the relationship between the amount of wear of the regulating blade 42 and the number of images formed under such image forming conditions. The squares in FIG. 36 represent the conditions of Example 4, and the black circles represent the amounts of wear of the regulating blade 42 actually measured under the conditions of Example 5. The solid line indicates the amount of wear of the regulating blade 42 predicted by Comparative Example 4. The broken line shows the wear amount of the regulating blade 42 predicted by Example 4, and the chain line shows the wear amount of the regulating blade 42 predicted by Example 5.

As shown in FIG. 36, the amount of wear on the regulating blade 42 varies depending on the magnetic force of the layer thickness regulating magnetic pole N1 unique to the developing device and the amount of gap between the developing sleeve 44 and the regulating blade 42. On the other hand, it can be seen that in Comparative Example 4, which was calculated without considering variations in the characteristic values of the developing device, the accuracy of wear amount prediction was lower than in Examples 4 and 5. On the other hand, in Examples 4 and 5, since the amount of wear is predicted in consideration of the magnetic force and the amount of gap, it can be seen that the deviation from the amount of actually measured wear is small and the prediction accuracy is high.

FIG. 37 shows the life transition of the developing device based on the amount of wear shown in FIG. 36. From FIG. 34, the wear threshold value _d1 for life judgment in Examples 4 and 5 is 10 μm and 12.2 μm, respectively. Further, the lifespan of the developing device can be confirmed in units of 1% on the display section 220. According to FIG. 36, the total wear amount of Examples 4 and 5 at the time of 500,000 sheets of image formation is 8.8 μm and 9.8 μm, respectively, and the life of the developing device is 88% and 80% from FIG. 37. . Although the total wear amount is larger in Example 5 in which the initial gap amount D(0) is smaller, the achieved life is smaller due to the difference in the wear threshold value _d1 for life judgment.

In this embodiment, by predicting the wear amount of the regulation blade 42 in consideration of the magnetic force and the gap amount, the replacement life of the developing device due to wear of the regulation blade 42 can be predicted with high accuracy. In addition, in this embodiment, in addition to the configuration of the first embodiment, the amount of wear of the regulating blade 42 was predicted by considering the magnetic force and the amount of gap. However, in addition to the configurations of the second and third embodiments, the amount of wear on the regulation blade 42 is predicted by considering the magnetic force and the amount of gap, and a message for replacing the developing device and the lifespan are displayed. You can also do it. Further, in this embodiment, the magnetic force Fr_b explained in the fourth embodiment is also taken into consideration, but without taking this into consideration, for example, the gap amount may be changed to the configuration of any one of the first to third embodiments. The amount of wear of the regulating blade 42 may be predicted by taking this into account.

<Other embodiments>
In the first embodiment described above, the amount of wear of the regulating blade 42 is predicted by considering the toner concentration, and in the second embodiment, the image ratio (specifically, the toner deterioration index) is predicted, and the amount of wear of the regulating blade 42 is predicted. The lifespan was predicted. However, these embodiments may be combined. For example, the amount of wear of the regulating blade 42 determined by taking into account the toner concentration as in the first embodiment may be corrected by taking into account the toner deterioration index. Further, the first to fifth embodiments can be implemented by appropriately combining two or more embodiments.

In each of the above-described embodiments, a configuration in which the developing device is replaceable as a cartridge has been described, but the cartridge may be a process cartridge that includes a developing device and a photosensitive drum as an image carrier.

1... Photosensitive drum (image carrier) / 4... Developing device (cartridge) / 41... Developing container / 42... Regulating blade (regulating member) / 44... Developing sleeve (developer carrying member) Body)/44a...Magnet roll (magnetic field generating means)/45...Toner density sensor (density detection means)/100...Image forming apparatus/101...Device main body/206...CPU/220 ...Display section (display means)/800...Notification section (transmission means)

Claims (16)

An image forming apparatus,
a developing container that is removably attached to the image forming apparatus and includes a developing device that develops an electrostatic latent image formed on an image carrier with toner, and that stores a developer containing toner and a carrier; A developer carrier that rotates while carrying the developer in the developer container, and a developer carrier that faces the developer carrier with a predetermined gap therebetween and regulates the amount of developer carried on the developer carrier. the cartridge including a regulating member and a concentration detection means for detecting the toner concentration in the developer container;
Display means for displaying information regarding replacement of the cartridge based on the toner concentration detected by the concentration detection means and the travel distance of the developer carrier,
The display means may be configured to display an image of a first density when the traveling distance of the developer carrier is the same and the toner density detected by the density detection means is a first density. , displaying information regarding replacement of the cartridge later at a second density in which the toner density is higher than the first density;
An image forming apparatus characterized by: The display means displays information regarding the lifespan of the cartridge based on the toner concentration detected by the concentration detection means and the travel distance of the developer carrier.
The image forming apparatus according to claim 1 , characterized in that: The display means may be configured to display an image of a first density when the traveling distance of the developer carrier is the same and the toner density detected by the density detection means is a first density. , displaying information regarding the lifespan of the cartridge such that the lifespan of the cartridge is longer when the toner density is higher at a second density than the first density;
The image forming apparatus according to claim 2 , characterized in that: The display means further displays information regarding replacement of the cartridge based on the image ratio of the toner image formed on the image carrier.
The image forming apparatus according to any one of claims 1 to 3 , characterized in that: The display means further displays information regarding the lifespan of the cartridge based on the image ratio of the toner image formed on the image carrier.
The image forming apparatus according to claim 4 , characterized in that: The display means displays information regarding replacement of the cartridge based on the rotational linear velocity of the developer carrier.
The image forming apparatus according to any one of claims 1 to 5 , characterized in that: The developer carrier has a magnetic field generating means having a plurality of magnetic poles therein,
The display means displays information regarding replacement of the cartridge based on magnetic force at a tip position of the regulating member facing the developer carrier.
The image forming apparatus according to any one of claims 1 to 6 , characterized in that: The display means displays information regarding replacement of the cartridge based on the predetermined gap between the developer carrier and the regulating member.
The image forming apparatus according to any one of claims 1 to 7 , characterized in that: The display means displays information regarding replacement of the cartridge based on the predetermined gap between the developer carrier and the regulating member at the time of manufacturing the cartridge.
The image forming apparatus according to any one of claims 1 to 8 , characterized in that: An image forming apparatus,
a developing container that is removably attached to the image forming apparatus and includes a developing device that develops an electrostatic latent image formed on an image carrier with toner, and that stores a developer containing toner and a carrier; A developer carrier that rotates while carrying the developer in the developer container, and a developer carrier that faces the developer carrier with a predetermined gap therebetween and regulates the amount of developer carried on the developer carrier. the cartridge including a regulating member and a concentration detection means for detecting the toner concentration in the developer container;
transmitting means for transmitting information regarding replacement of the cartridge to an external device based on the toner concentration detected by the concentration detecting means and the travel distance of the developer carrier ;
The transmitting means may be configured to detect a first density of toner when the traveling distance of the developer carrier is the same and the toner density detected by the density detecting means is a first density. , when the second toner density is higher than the first density, information regarding replacement of the cartridge is transmitted to the external device later;
An image forming apparatus characterized by: The transmitting means transmits information regarding the lifespan of the cartridge to the external device based on the toner concentration detected by the concentration detecting means and the traveling distance of the developer carrier.
The image forming apparatus according to claim 10 . The transmitting means may be configured to detect a first density of toner when the traveling distance of the developer carrier is the same and the toner density detected by the density detecting means is a first density. , transmitting information regarding the lifespan of the cartridge to the external device so that the lifespan of the cartridge is longer when the toner density is higher at a second density than the first density;
The image forming apparatus according to claim 11 , characterized in that: The transmitting means further transmits information regarding replacement of the cartridge to the external device based on an image ratio of the toner image formed on the image carrier.
The image forming apparatus according to any one of claims 10 to 12 . The transmitting means further transmits information regarding the lifespan of the cartridge to the external device based on the image ratio of the toner image formed on the image carrier.
The image forming apparatus according to claim 13 , characterized in that: The regulating member is made of resin.
The image forming apparatus according to any one of claims 1 to 14 , characterized in that: The cartridge is the developing device,
The image forming apparatus according to any one of claims 1 to 15 , characterized in that:

Images