JP2016161645A - Image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technology capable of more appropriately determining the life of a developing device.SOLUTION: An image forming apparatus comprises: a remaining amount acquisition part that acquires the amount of a developer to be stored in a developer container; a coefficient acquisition part that acquires a correction coefficient according to the amount of the developer to be stored in the developer container; a correction distance acquisition part that, every time the distance of travel of a developer carrier increases by a predetermined distance, acquires a correction distance obtained by correcting the predetermined distance with the correction coefficient, and acquires the total correction distance obtained by integrating the correction distances; and a life determination part that the life of a developing device has expired when the total correction distances acquired by the correction distance acquisition part exceeds a predetermined threshold or the amount of the developer acquired by the remaining amount acquisition part falls to a predetermined threshold or less.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an image forming apparatus using an electrophotographic system.

  An image forming apparatus that forms an image on a recording material such as paper by an electrophotographic image forming process such as a copying machine or a printer forms an image using a developer. Specifically, the charged photosensitive drum is exposed to form an electrostatic latent image corresponding to the image information on the drum surface, the electrostatic latent image is developed with a developer and visualized as a developer image, An image is formed by transferring and fixing the developer image onto a recording material. In the image forming process, the developer remaining on the photosensitive drum or the like is collected by a cleaning device or the like and used for the next image forming process.

  As the number of image formation increases, a developer that is collected many times without being transferred to the recording material is generated. Such a developer is deteriorated by repeating the formation of a developer image many times, so that the added external additive is released from or embedded in the resin particles as a base of the developer. May occur. In such a case, the developer cannot obtain a desired amount of charge, which may result in an image density that is not appropriate, and so-called fogging or the like in which the developer adheres to the white background portion of the transfer material may occur. . Therefore, Patent Document 1 and Patent Document 2 disclose what calculates the degree of deterioration of the developer in the developing device of the image forming apparatus and determines that the developing device has reached the end of its life by integrating the calculated degrees. Yes.

Japanese Patent No. 4743273 Japanese Patent No. 5383750

  However, the apparatus disclosed in Patent Document 1 also has the following problems. In the developing device, the developer accommodated in the developer accommodating portion is supplied to the developing roller (developer carrier) by the supply roller, and the layer thickness on the developing roller is regulated by the developing blade (regulating member), A desired charge amount is given by rubbing with the developing blade. Thereafter, the developer is conveyed to a developing position that is a portion where the developing roller and the photosensitive drum are opposed to each other, and is used for developing the electrostatic latent image on the photosensitive drum. By performing such an image forming operation, the developer image formation is continued repeatedly. During this time, the developing roller constantly rubs against the developing blade and the supply roller. Therefore, due to this rubbing, the developer and the external additive added to the developer may adhere to the developing roller. Then, as image formation is repeated, that is, as the cumulative travel distance of the developing roller from the start of use of the developing roller becomes longer, the developer and the external additive added to the developer become more developed. It will accumulate on the roller.

  When the developer or the external additive added to the developer accumulates on the developing roller as described above (hereinafter, this phenomenon is called filming), the surface roughness of the developing roller is reduced, and the developing roller The electrical resistance value increases. Due to this filming, that is, because the developing roller is deteriorated, a desired charge amount cannot be given to the developer, and the developer layer thickness on the developing roller necessary for developing the electrostatic latent image cannot be secured. And other harmful effects are caused. As a result, an appropriate image density cannot be obtained, and problems such as density unevenness in fog and halftone are generated.

  Further, not all of the developer on the developing roller is necessarily used for developing the electrostatic latent image. In a white background portion (a portion where no image is formed) of a recording material such as paper, the developer remains on the developing roller. The developer on the developing roller that has not been used for developing the electrostatic latent image is returned again to the developer container of the developing device. The developer that has not been used for developing the electrostatic latent image is deteriorated by being rubbed between the developing roller and the developing blade and between the developing roller and the supply roller. As the image forming apparatus is used and the amount of developer in the developer accommodating portion is reduced, the deterioration of the developer is further advanced as a whole. In such a state where the remaining amount of the developer is small and the developer is generally deteriorated, filming of the developing roller is likely to occur. Further, when the developer has been further deteriorated and the cumulative travel distance of the developing roller from the start of use of the developing roller is long, filming of the developing roller may occur more remarkably. Therefore, it is necessary to determine a more optimal life of the developing device in consideration of deterioration (filming) of the developing roller.

  An object of the present invention is to provide a technique capable of more appropriately determining the life of a developing device.

In order to achieve the above object, an image forming apparatus of the present invention includes:
An image forming apparatus for forming an image on a recording material,
An image carrier that carries a developer image transferred to a recording material;
A developing device comprising: a developer carrying member that carries a developer for forming the developer image; and a developer container that contains a developer supplied to the developer carrying member;
A remaining amount acquisition unit for acquiring the amount of developer accommodated in the developer container;
A coefficient acquisition unit that acquires a correction coefficient according to the amount of developer contained in the developer container;
Whenever the travel distance of the developer carrier increases by a predetermined distance, a correction distance obtained by correcting the predetermined distance by the correction coefficient is obtained, and a total correction distance obtained by integrating the correction distance is obtained. And
When the total correction distance acquired by the correction distance acquisition unit exceeds a predetermined threshold, or when the amount of developer acquired by the remaining amount acquisition unit is equal to or less than a predetermined threshold remaining amount, the development A life determination unit that determines that the device has reached the end of its life;
It is characterized by providing.

  According to the present invention, it is possible to more appropriately determine the life of the developing device.

1 is a schematic configuration diagram of an image forming apparatus according to a first embodiment. 1 is a schematic configuration diagram of a process cartridge P in Embodiment 1. FIG. Lifetime judgment sequence chart of developing device 400 in Embodiment 1 Relationship between developer remaining amount TJ and developing roller travel distance correction coefficient k in Example 1 Transition of remaining life of developing roller 401 in cases 1 and 2 in the first embodiment Transition of remaining life of developing roller 401 in case 3 in the first embodiment Development roller life line in embodiment 1 Schematic configuration diagram of an image forming apparatus in Embodiment 2. Life Determining Sequence Chart of Developing Device 400 in Embodiment 2 Relationship between absolute water content and environmental correction coefficient z in Example 2 Transition of remaining life of developing roller 401 in Embodiment 2 Life Determining Sequence Chart of Developing Device 400 in Embodiment 3 Transition of remaining life of developing roller 401 in Embodiment 3

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be exemplarily described in detail with reference to the drawings. However, the dimensions, materials, shapes, and relative arrangements of the components described in this embodiment should be appropriately changed according to the configuration of the apparatus to which the invention is applied and various conditions. That is, it is not intended to limit the scope of the present invention to the following embodiments.

<Example 1>
With reference to FIG. 1, an image forming apparatus according to Embodiment 1 of the present invention will be described. FIG. 1 is a schematic configuration diagram of an image forming apparatus according to the first embodiment. The image forming apparatus according to the first exemplary embodiment is an electrophotographic image forming apparatus that forms an image on a recording medium by executing a series of image forming processes of charging, exposing, developing, transferring, and cleaning the photosensitive drum. . Specific examples of the image forming apparatus include an electrophotographic copying machine, an electrophotographic printer (for example, a laser beam printer, an LED printer), a facsimile machine, and a word processor.

  Here, the image forming apparatus that executes the above-described series of image forming processes is roughly the photosensitive drum 100, the charging device 200, the latent image exposing device 300, the developing device 400, the transfer device 500, the fixing device 800, the cleaning device 600, Is provided. The charging device 200 is a charging unit that uniformly charges the surface of the photosensitive drum 100, and the latent image exposure device 300 exposes the charged photosensitive drum 100 according to image data to generate an electrostatic latent image. Form. The developing device 400 visualizes an electrostatic latent image formed on the photosensitive drum 100 as an image carrier using a developer T by bringing a developing roller 401 as a developer carrier into contact with the electrostatic latent image. Let The transfer device 500 transfers the developer image formed on the photosensitive drum 100 to a recording medium 900 (recording material) such as paper, and the fixing device 800 fixes the developer image on the recording medium 900. The cleaning device 600 cleans the surface of the photosensitive drum 100 after transfer.

(Overall configuration of image forming apparatus)
In the image forming apparatus according to the first exemplary embodiment, a charging device 200, a latent image exposure device 300, a developing device 400, a transfer device 500, and a cleaning device 600 are sequentially arranged on the peripheral surface of the photosensitive drum 100. The photosensitive drum 100 rotates in the direction of R1 in FIG. 1 to form an image. As the photosensitive drum 100, a photosensitive drum in which an undercoat layer, a carrier generation layer, and a carrier transport layer were sequentially formed on a conductive aluminum cylinder was used. The charging device 200 contacts the photosensitive drum 100 and rotates following the photosensitive drum 100 to form an image. A predetermined charging bias is applied to the charging device 200 to uniformly charge the photosensitive drum 100. The latent image exposure apparatus 300 scans and outputs laser light modulated in accordance with an image signal. When the photosensitive drum 100 uniformly charged by the charging device 200 is irradiated with laser light from the latent image exposure device 300, an electrostatic latent image is formed.

  The developing device 400 includes a developing roller 401 (developer carrying member), a supply roller 402 (developer supplying member), a developing blade 403 (regulating member), and a developer container having a developing chamber 405 and a developer containing chamber 404. Prepare. Developer T is stored in developer storage chamber 404. The developing roller 401 rotates with a predetermined peripheral speed ratio with respect to the photosensitive drum 100, and contacts the photosensitive drum 100 to convert the electrostatic latent image formed on the photosensitive drum 100 to the developer T. To develop a visible image as a developer image. Here, a predetermined developing bias is applied to the developing roller 401. For developer T, a non-magnetic one-component developer was used.

The recording medium 900 is supplied and transported to the transfer device 500 in synchronization with the formation of the electrostatic latent image on the photosensitive drum 100 by the paper feed roller 701. A predetermined transfer bias is applied to the transfer device 500, and the developer image on the photosensitive drum 100 is transferred onto the recording medium 900. The recording medium 900 to which the developer image has been transferred is conveyed to the fixing device 800 and permanently fixed, and then discharged outside the image forming apparatus main body. On the other hand, the developer T remaining on the photosensitive drum 100 without being transferred is removed by the cleaning device 600 using the cleaning blade 601 formed of an elastic blade and stored in the cleaning container 602.

  In Embodiment 1, the photosensitive drum 100, the charging device 200, the cleaning device 600, and the developing device 400 are integrated to form a process cartridge P that can be easily attached to and detached from the image forming apparatus. The process cartridge P further includes a memory M which is a nonvolatile storage unit. The memory M also stores use information and life information of the developing roller 401, and use information and life information of the developer T. As a result, even when the image forming apparatus main body power is turned ON / OFF or when the process cartridge P is replaced, the usage status and replacement time (life) of the developing device 400 can be calculated accurately and quickly. Can do.

  The image forming apparatus is also provided with a developing roller travel distance calculating device 1001. The developing roller travel distance calculating device 1001 includes a developing roller travel distance measuring unit 1002 that counts the travel distance W of the developing roller 401 and a developing roller travel distance calculating unit 1003 that corrects the travel distance W of the developing roller 401. It has been. Further, the control unit 1000 configured by a CPU or the like that controls the image forming apparatus main body has reached the life of the developing device 400 from the remaining developing roller life GJ calculated by the developing roller travel distance calculating device 1001 as a life determination unit. Judge whether or not.

(Developing device 400)
With reference to FIG. 2, the developing device 400 of Example 1 will be described in detail. FIG. 2 is a schematic configuration diagram of the process cartridge P. In the developing device 400, the developing roller 401 and the supply roller 402 are rotatably supported in the developing chamber 405. The supply roller 402 is disposed so as to be in contact with the peripheral surface of the developing roller 401. The rotation direction of the developing roller 401 and the supply roller 402 is the same direction (reverse direction on the peripheral surface of the contact portion) as indicated by arrows R2 and R3 in FIG. The developing roller 401 is provided with a conductive elastic rubber layer having a predetermined volume resistance around a metal core. The supply roller 402 has a foamed urethane layer around a metal core. In the surface layer of the foamed urethane layer, foamed cells are opened so that the developer T can be easily held and transported.

  The developing blade 403 is made of an elastic plate such as flexible phosphor bronze, and one end thereof is fixed to the developing chamber 405. The plate surface near the free end of the developing blade 403 is disposed so as to slide on the surface of the conductive elastic rubber layer of the developing roller 401. The developer agitating member 406 is provided inside the developer storage chamber 404 and is configured to be rotatable about a rotation shaft 407. As a result, the developer T in the developer container 404 is agitated and the developer T is fed into the developing chamber 405.

The movement of the developer T in the driving developing device 400 will be described.
When the developing device 400 is driven by a driving device (not shown), each of the developing roller 401, the supply roller 402, and the developer stirring member 406 rotates in the direction of the arrow in FIG. As the developer stirring member 407 in the developer storage chamber 404 rotates, the developer T in the developer storage chamber 404 is stirred and transported toward the supply roller 402 in the development chamber 405. The developer T held on the foamed urethane layer of the supply roller 402 is sent to the contact portion with the development roller 401 by the rotation of the supply roller 402. The developer T reaching the contact portion is rubbed by the surfaces of the developing roller 401 and the supply roller 402 moving in opposite directions, and a part of the developer T is transferred and adhered to the surface of the developing roller 401.

The developer T adhering to the surface of the developing roller 401 is sent to the developing blade 403 as the developing roller 401 rotates. The developing blade 403 regulates the amount of the developer T adhering to the surface of the developing roller 401 to form a uniform thin layer, and frictionally charges the developer T. The thinned developer T is sent to the contact portion with the photosensitive drum 100 as the developing roller 401 rotates, and is used to develop the electrostatic latent image formed on the photosensitive drum 100. The developer T that is not used for development and remains on the surface of the developing roller 401 is conveyed to a contact portion with the supply roller 402 and is removed from the surface of the developing roller 401 by the supply roller 402. The removed developer T is sent into the developer container 404 and stirred and mixed with the developer T in the developer container 404.

(Developer remaining amount detection device 1004)
The developer remaining amount detection device 1004 (remaining amount acquisition unit) based on the video count method employed in the first embodiment will be described. The image forming apparatus includes a developer remaining amount detecting device 1004 that detects the remaining amount of developer T in the developing device 400. The developer remaining amount detection device 1004 includes a video count measuring unit 1005 that measures pixel information (number of pixel signals: video count value) of an output image formed on the recording medium 900 by an image forming operation. The developer remaining amount detecting device 1004 includes a developer remaining amount calculating unit 1006 that calculates the remaining amount of the developer T in the developing device 400 from the measured video count value.

The video count measurement unit 1005 measures pixel information (video count value VCn) of the output image. In this embodiment, one recording medium 900 to be output is defined as one video count value VCn (amount of developer used). In the developer remaining amount calculating unit 1006, first, the video count value VCn measured by the video count measuring unit 1005 is added to the cumulative video count value VCr from the start of use of the process cartridge P stored in the memory M of the process cartridge P. to add. Thereby, the total video count value VCt is calculated.
VCt = VCr + VCn

Next, the developer remaining amount calculation unit 1006 calculates the developer remaining amount TJ in the developing device 400 from the video count threshold value VCth and the total video count value VCt stored in the memory M.
TJ [%] = (1-VCt / VCth) × 100
Then, the remaining developer calculating unit 1006 writes the total video count value VCt in the memory M as the cumulative video count value VCr.

  Here, when the developer remaining amount TJ = 100%, the developer T in the developing device 400 is in a full state and the process cartridge P is new. In addition, when the developer remaining amount TJ = 0%, the remaining amount of the developer T in the developing device 400 almost disappears, indicating that it is time to replace the process cartridge P.

(Developing roller travel distance calculation device 1001)
Next, the developing roller travel distance calculating device 1001 that corrects the travel distance W of the developing roller 401, which is a feature of the present invention, will be described in detail. In the first embodiment, for each predetermined developing roller travel distance Wu, the remaining amount of the developer T in the developing device 400 is referred to, and the developing roller travel distance correction coefficient k corresponding to the remaining amount of the developer T is used. Thus, the travel distance W of the developing roller 401 is corrected. The developing roller travel distance calculating device 1001 uses the developing roller travel distance measuring unit 1002 that measures the travel distance W of the developing roller 401 and the developing roller travel distance correction coefficient k to correct the travel distance W of the developing roller 401. A roller travel distance calculation unit 1003.

The developing roller travel distance measuring unit 1002 measures the travel distance W from the driving time Td of the developing device 400, the process speed Ps of the image forming apparatus, and the peripheral speed ratio Sr of the developing roller 401 to the photosensitive drum 100. Here, the travel distance W is the distance that a certain point on the surface of the developing roller 401 has advanced by the rotation of the developing roller 401. Further, the process speed Ps of the image forming apparatus is the rotational speed of the photosensitive drum 100. Specifically, the travel distance W of the developing roller 401 is obtained by the following calculation formula.
W = Td × Ps × Sr

The developing roller travel distance calculation unit 1003 first performs development by the remaining amount detection device 1004 for each predetermined development roller travel distance Wu measured by the development roller travel distance measurement unit 1002 (every time the travel distance increases by a predetermined distance). The remaining amount TJ is referred to. Then, the developing roller travel distance calculation unit 1003 reads the developing roller travel distance correction coefficient k corresponding to the developer remaining amount TJ stored in the memory M as a coefficient acquisition unit. In the first embodiment, the predetermined developing roller travel distance Wu is about two A4 sheets = 300 mm. The developing roller travel distance calculation unit 1003 calculates a corrected development roller travel distance Hu (correction distance) by multiplying a predetermined development roller travel distance Wu by the development roller travel distance correction coefficient k as a correction distance acquisition unit. To do. Specifically, the corrected developing roller travel distance Hu is obtained by the following calculation formula.
Hu = k × Wu

Next, the development roller travel distance Hu after correction is added (integrated) to the development roller travel distance Hr after the cumulative correction from the start of use of the process cartridge P stored in the memory M, whereby the development roller after the total cumulative correction is added. The travel distance Ht (total correction distance) is calculated. Specifically, it is obtained by the following calculation formula.
Ht = Hr + Hu
Then, the developing roller remaining life GJ is calculated from the developing roller travel distance threshold Wth stored in the memory M and the development roller travel distance Ht after total accumulation correction.
GJ [%] = (1-Ht / Wth) × 100

Then, the development roller travel distance Ht after total accumulation correction is written in the memory M as the development roller travel distance Hr after accumulation correction.
Here, when the developing roller remaining life GJ = 100%, the developing device 400 is new. When the remaining developing roller life GJ ≦ 0% (that is, when the development roller travel distance Ht after the total cumulative correction exceeds the development roller travel distance threshold Wth), the developing device 400 has reached the end of its life. This indicates that the cartridge P is in the replacement period.

(Developing device 400 life determination sequence)
FIG. 3 is a sequence chart for determining the life of the developing device 400 according to the first embodiment. The control unit 1000 can detect the lifetime of the developing device 400 and notify the user of the detection result by performing each process shown in the flowchart of FIG. 3 based on the information in the memory M of the process cartridge P. .

First, when a print signal is sent to the image forming apparatus (S101), the developing device 400 is driven to start an image forming operation (S102). The developing roller travel distance calculation unit 1003 refers to the developer remaining amount TJ of the developer remaining amount detecting device 1004 for each predetermined developing roller travel distance Wu (S103). Then, the corrected developing roller travel distance Hu is calculated using the developing roller travel distance correction coefficient k corresponding to the developer remaining amount TJ (S104). From the corrected development roller travel distance Hu and the corrected corrected development roller travel distance Hr stored in the memory M, the total corrected development roller travel distance Ht is calculated (S105). Thereafter, a developing roller remaining life GJ is calculated (S106). Then, it is determined whether the developing roller remaining life GJ is 0% or less (S107). If it has reached 0% or less, the accumulated developing roller travel distance Hr is written in the memory M (S109), and the developing device 400 has reached the end of its life on the operation panel OP provided in the image forming apparatus main body. (S110). If it has not reached 0% or less, the cumulatively corrected developing roller travel distance Hr is written in the memory M (S108) and prepared for the next image formation.

  On the other hand, in the developer remaining amount detecting device 1004, after receiving the image information (S111), the video count measuring unit 1005 measures the video count value VC, and the developer remaining amount calculating unit 1006 calculates the total video count value VCt. Calculate (S112). Thereafter, a developer remaining amount TJ is calculated (S113). Then, it is determined whether or not the developer remaining amount TJ is 0% or less (whether or not it is less than a predetermined threshold remaining amount) (S114). If it has reached 0% or less, the cumulative video count value VCr is written to the memory M (S116), and the remaining amount of the developer T of the developing device 400 is almost eliminated in the operation panel OP, and the developing device 400 is replaced at the time of replacement. A notification is made (S110). If it has not reached 0% or less, the cumulative video count value VCr is written in the memory M (S115) and prepared for the next image formation. The timing for acquiring the developer amount may be a predetermined traveling distance Wu that is a detection timing of the traveling distance, that is, a time interval for traveling the predetermined traveling distance. Alternatively, it may be a time interval obtained by multiplying the time required to travel a predetermined travel distance by a multiple (multiple times within the time required to travel a predetermined travel distance).

  By executing this series of flowcharts, in the first embodiment, the developing device 400 corrects and accumulates the travel distance W of the developing roller 401 with the developing roller travel distance correction coefficient k corresponding to the remaining amount of the developer T. Can be notified to the user by determining the lifetime. Further, in the first embodiment, the detection result of the developer remaining amount detection device 1004 is also used together to notify that the developer T of the developing device 400 is almost gone. In this way, not only the life of the developing device 400 due to the deterioration (filming) of the developing roller 401 but also the life of the developing device 400 due to the remaining amount of the developer T can be notified, and a more optimal life of the developing device 400 can be reported. Can be notified to the user.

  Further, the life warning threshold WL may be set before the developing roller travel distance threshold Wth reaches the development roller travel distance threshold Wth. That is, when the development roller travel distance Ht after the total cumulative correction reaches or exceeds the life warning threshold WL, control may be performed so as to issue a life warning of the developing device 400. For example, when the lifetime notice threshold WL is set to be 90% of the developing roller travel distance threshold Wth, when the remaining life GJ of the developing roller 401 reaches 10%, the lifetime of the developing device 400 is near to the user. It becomes possible to alert | report the warning of being. Therefore, the user can prepare for the replacement of the process cartridge P in advance.

  Further, in Example 1, when the remaining developing roller life GJ reaches 0%, the life of the developing device 400 is determined. However, the developing roller remaining life GJ can be displayed on the operation panel OP each time the developing roller travel distance Ht after the total cumulative correction is updated. In that case, since it is possible to inform the user of how long the developing roller 401 is, it is possible to provide an image forming apparatus with more excellent usability.

<Specific example>
With reference to FIGS. 4-7, the specific example which applied Example 1 more concretely is demonstrated. In Example 1, the developing roller travel distance correction coefficient k is set as shown in FIG. 4 according to the developer remaining amount TJ. That is, the amount of the developer stored in the developer container is divided into a plurality of ranges, and one correction coefficient (a constant coefficient within one section) is assigned to one section.

FIGS. 5A, 5B, and 6 show an example in which an image forming apparatus is used by changing a printing area (printing rate: consumption of developer per sheet) printed on one recording medium 900. FIG. FIG. 6 is a diagram illustrating a relationship between a developer remaining amount TJ at the time when printing is performed and a remaining life of the developing roller 401; In each figure, the vertical axis represents the developer remaining amount TJ, and the horizontal axis represents the remaining life of the developing roller 401. Here, in each figure, Zone 1 is an area to which the developing roller travel distance correction coefficient k 1 is applied, Zone 2 is an area to which the developing roller travel distance correction coefficient k 2 is applied, and Zone 3 is an area to which the developing roller travel distance correction coefficient k 3 is applied. Represents the area to be applied. When calculating the corrected developing roller travel distance Hu, it is determined which developing roller travel distance correction coefficient k is used depending on which zone the developer remaining amount TJ is. In each figure, the solid line represents the transition of the developing roller remaining life GJ when the traveling distance W of the developing roller 401 is corrected, and the wavy line represents the developing roller 401 when the traveling distance W of the developing roller 401 is not corrected. It shows the transition of remaining life.

<Case 1>
FIG. 5A shows a case where printing is performed at a constant printing rate of about 1%. In this case, since it is always Zone1, the developing roller travel distance correction coefficient k1 = 1.0 is applied. Therefore, the remaining lifetime GJ of the developing roller overlaps with the remaining lifetime of the developing roller 401 that has not been corrected. At point A1, the developing roller remaining life GJ reaches 0%, and the life of the developing device 400 is notified. Further, when printing is continued beyond the point A1, image defects such as fogging due to filming of the developing roller 401 occur.

<Case 2>
FIG. 5B shows a case where printing is performed at a constant printing rate of about 1 to 2%. In this case, the developer remaining amount TJ up to 40% (first amount) is Zone1, and the developing roller travel distance correction coefficient k1 = 1.0 is applied. Further, when the developer remaining amount TJ is 40% or more (second amount), Zone 2 is set, and the developing roller travel distance correction coefficient k2 = 1.7 is applied. Therefore, the developing roller remaining life GJ indicated by the solid line changes from the point B1 where the developer remaining amount TJ = 40%. That is, as compared with the case where the travel distance W of the broken developing roller 401 is not corrected, the traveling distance W of the developing roller 401 proceeds from the point B1 even if the same amount of developer T is consumed. Appears to be faster. The solid line developing roller remaining life GJ reached 0% at the point A2, and the life of the developing device 400 was notified. Here, in the case where the travel distance W of the developing roller 401 indicated by the broken line is not corrected, if the printing is further continued beyond the point B 2, image defects such as fogging due to filming of the developing roller 401 occur. Therefore, by correcting the traveling distance W of the developing roller 401, the life of the developing device 400 can be notified without causing image defects due to filming of the developing roller 401.

<Case 3>
FIG. 6 shows a case where printing is performed at a constant printing rate of about 7 to 8%. In this case as well, the developer remaining amount TJ is Zone 1 up to 40%, and the developing roller travel distance correction coefficient k1 = 1.0 is applied. Further, when the developer remaining amount TJ is 40% or later, Zone 2 is obtained, and the developing roller travel distance correction coefficient k2 = 1.7 is applied. In addition, when the developer remaining amount TJ is 20% or later, Zone 3 is obtained, and the developing roller travel distance correction coefficient k3 = 6.0 is applied. Therefore, the inclination of the solid developing roller remaining life GJ changes from the point B6 where the developer remaining amount TJ = 40% and the point B7 where the developer remaining amount 20%. That is, compared to the case where the travel distance W of the developing roller 401 indicated by the broken line is not corrected, the traveling distance W of the developing roller 401 is apparently faster from the points B6 and B7. When the remaining developing roller remaining life GJ reaches the point B8, the remaining developer amount TJ by the remaining developer detecting device 1004 becomes 0%, and the life of the developing device 400 is notified.

Here, specific examples of <Case 1> to <Case 3> are arranged. In each case, when the developing roller remaining life GJ with the travel distance W of the developing roller 401 corrected reaches 0%, the reaching point of the remaining life% of the developing roller 401 without correction is connected with a straight line. FIG. 7 shows the development roller life line GS. The developing roller life line GS is a line on which the developing roller 401 reaches the end of life when the travel distance W of the developing roller 401 is not corrected. In other words, when the traveling distance W of the developing roller 401 that has not been corrected crosses the developing roller life line GS, the life of the developing roller 401 is reached.

  As can be seen from FIG. 7, when the remaining life of the developing roller 401 is small (the cumulative travel distance of the developing roller 401 is long) and the remaining amount of developer TJ is small, that is, the remaining life of the developing roller 401 reaches 0%. The developing roller life line GS is drawn in front. As described above, when the cumulative traveling distance of the developing roller 401 is long and the remaining amount of the developer T is reduced, filming of the developing roller 401 is likely to occur. That is, filming is likely to occur in the region F shown in FIG. Therefore, by correcting the traveling distance W of the developing roller 401, the life of the developing roller 401 can be extended before reaching the region F, that is, before filming of the developing roller 401 occurs.

  As described above, the optimum life of the developing roller 401 is notified by correcting the traveling distance W of the developing roller 401 using the developing roller traveling distance correction coefficient k corresponding to the remaining amount of the developer T. I can do it. In particular, when the developer remaining amount TJ in the developing device 400 is small and the cumulative travel distance of the developing roller 401 from the start of use of the process cartridge P is long, a more optimal life of the developing roller 401 can be notified. In this case, a good image can be obtained without causing image degradation due to deterioration (filming) of the developing roller 401. Further, it is possible to notify the user of the further optimal life of the developing device 400 by notifying the developer remaining amount detecting device 1004 that the developer T is almost exhausted.

  In the first embodiment, the developer remaining amount detecting device 1004 using the video count method has been described. However, the developer remaining amount detecting device 1004 is not limited to this. For example, a remaining amount detection method using electrostatic capacity or a light transmission remaining amount detection method may be used, or a combination thereof may be used. Specifically, when the developer remaining amount acquired by the video count method (first acquisition method) is equal to or less than a predetermined remaining amount (second predetermined threshold remaining amount), the electrostatic capacity method (first 3 acquisition method) or a light transmission method (second acquisition method) may be used. In other words, a more suitable remaining amount acquisition method may be selected according to the level of the remaining amount of developer. Note that the electrostatic capacity method uses an electrode whose electrostatic capacity that is detected in accordance with a change in the state of the developer inside the container portion of the developer container (for example, a conductive member is attached to the inner wall of the container). In this method, the amount of developer is acquired based on the detected change in capacitance. This is a conventionally well-known method and will not be described in detail. The light transmission method uses a light source that irradiates light inside the developer accommodating portion of the developer container and a light receiving portion that receives light that has passed through the accommodating portion, and changes the light receiving state of the light receiving portion. This is a method for obtaining the amount of the developer based on the above. This method is also a well-known method and will not be described in detail.

Furthermore, in the first embodiment, the relationship between the developer remaining amount TJ and the developing roller travel distance correction coefficient k as shown in FIG. 4 is used, but the present invention is not limited to this. It is also possible to set the developer remaining amount TJ more finely and to set a different developing roller travel distance correction coefficient k for each. Further, the life determination of the developing device 400 based on the various calculations described above may be calculated and controlled during the operation of the device, or may be controlled using a table stored in advance in the storage unit of the CPU. Further, the specific numerical value of the correction coefficient is not limited to 1.0 or more as in the above embodiment. The progress of deterioration of the developing roller differs depending on the atmospheric environment (low temperature, low humidity, high temperature, high humidity, etc.) and color (yellow, magenta, cyan, black), etc., and the total correction distance becomes longer than the total non-correction distance. In some cases. For example, the correction coefficient may be 0.8 or the like.
In this embodiment, the amount of developer is divided into three ranges and one correction coefficient is assigned to one division. However, the present invention is not limited to this. What is necessary is just to make several divisions, and if it controls more finely, what is necessary is just to increase divisions, such as four or five.
In this embodiment, if the amount of the developer is reduced, the value of the correction coefficient corresponding to the developer is increased. However, the present invention is not limited to this. There may be a case where the correction coefficient becomes smaller in the middle of the plurality of sections. This is because the developer is also consumed, but the case where a new developer is added and the state of the developer changes may be considered depending on the cartridge configuration.
In this embodiment, the correction coefficient in the category is constant.

<Example 2>
A second embodiment of the present invention will be described. Note that matters not described below are the same as those in the first embodiment. The deterioration (filming) of the developing roller 401 depends on the temperature and humidity of the environment in which the image forming apparatus is used (atmosphere environment of the image forming apparatus). In particular, in a low-temperature and low-humidity environment, the charge amount of the developer T becomes high, so that the developers T aggregate and the fluidity tends to decrease. Therefore, when the developing roller 401 rubs against the developing blade 403 and the supply roller 402, the external additive added to the developer T is likely to adhere to the surface of the developing roller 401. Such a phenomenon becomes more prominent as the developer remaining amount TJ in the developing device 400 is small and the cumulative travel distance of the developing roller 401 from the start of use of the process cartridge P becomes longer.
In the second embodiment, a case where the developing roller travel distance correction coefficient k is corrected by the temperature and humidity of the environment in which the image forming apparatus is used will be described. The overall configuration of the image forming apparatus is almost the same as that of the first embodiment.

(Image forming device)
FIG. 8 is a schematic configuration diagram of an image forming apparatus in Embodiment 2 of the present invention. The image forming apparatus according to the second exemplary embodiment includes a temperature / humidity sensor 1007 (temperature / humidity detection unit) that detects temperature and humidity of an environment in which the image forming apparatus is used. The controller 1000 calculates absolute humidity (moisture content per unit volume: absolute water content [g / m ³ ]) from the temperature / humidity detection result of the temperature / humidity sensor 1007.

  In the memory M of the process cartridge P, the developing roller 401 including an accumulated correction developing roller traveling distance Hr, a developing roller traveling distance threshold Wth, a developing roller traveling distance correction coefficient k, and an environmental correction coefficient z corresponding to the absolute moisture amount, and the like. Stores usage information and lifetime information. Further, the memory M also stores usage information and life information of the developer T such as the cumulative video count value VCr and the video count threshold value VCth.

(Developing roller travel distance calculation device 1001)
Next, the developing roller travel distance calculating device 1001 that corrects the travel distance W of the developing roller 401 using the environment correction coefficient z, which is a feature of the second embodiment, will be described in detail. The developing roller travel distance calculating device 1001 uses the developing roller travel distance measuring unit 1002 that measures the travel distance W of the developing roller 401 and the developing roller travel distance correction coefficient k to correct the travel distance W of the developing roller 401. A roller travel distance calculation unit 1003.

The developing roller travel distance measuring unit 1002 measures the travel distance W from the driving time Td of the developing device 400, the process speed Ps of the image forming apparatus, and the peripheral speed ratio Sr of the developing roller 401 to the photosensitive drum 100. Here, the travel distance W is the distance that a certain point on the surface of the developing roller 401 has advanced by the rotation of the developing roller 401. Further, the process speed Ps of the image forming apparatus is the rotational speed of the photosensitive drum 100. Specifically, the travel distance W of the developing roller 401 is obtained by the following calculation formula.
W = Td × Ps × Sr

The developing roller travel distance calculation unit 1003 first refers to the developer remaining amount TJ by the developer remaining amount detection device 1004 for each predetermined developing roller travel distance Wu measured by the developing roller travel distance measuring unit 1002. Then, the developing roller travel distance calculation unit 1003 reads the developing roller travel distance correction coefficient k corresponding to the developer remaining amount TJ stored in the memory M as a coefficient acquisition unit. In the second embodiment, the predetermined developing roller travel distance Wu is about two A4 sheets = 300 mm. Further, the developing roller travel distance calculation unit 1003 also reads out an environmental correction coefficient z corresponding to the absolute water content stored in the memory M as an environmental coefficient acquisition unit. Then, the developing roller travel distance calculation unit 1003, as a correction distance acquisition unit, multiplies the predetermined developing roller travel distance Wu by the development roller travel distance correction coefficient k and the environment correction coefficient z to obtain the corrected development roller travel distance Hu. Calculate (acquire). Specifically, the corrected developing roller travel distance Hu is obtained by the following calculation formula.
Hu = k × z × Wu

Next, the corrected development roller travel distance Hu is added to the cumulative correction development roller travel distance Hr from the start of use of the process cartridge P stored in the memory M, whereby the total cumulative correction development roller travel distance Ht. Is calculated. Specifically, it is obtained by the following calculation formula.
Ht = Hr + Hu
Then, the developing roller remaining life GJ is calculated from the developing roller travel distance threshold Wth stored in the memory M and the development roller travel distance Ht after total accumulation correction.
GJ [%] = (1-Ht / Wth) × 100

Then, the development roller travel distance Ht after total accumulation correction is written in the memory M as the development roller travel distance Hr after accumulation correction.
Here, when the developing roller remaining life GJ = 100%, the developing device 400 is new. Further, when the developing roller remaining life GJ = 0%, the developing device 400 has reached the end of its life and the process cartridge P is in the replacement period.

(Developing device 400 life determination sequence)
FIG. 9 is a sequence chart for determining the life of the developing device 400 according to the second embodiment. The control unit 1000 can detect the lifetime of the developing device 400 and notify the user of the detection result by performing each process shown in the flowchart of FIG. 9 based on the information in the memory M of the process cartridge P. .

  First, when a print signal is sent to the image forming apparatus (S201), the control unit 1000 calculates the absolute moisture content of the environment in which the image forming apparatus is used from the detection result of the temperature / humidity sensor 1007 (S202). Thereafter, the developing device 400 is driven to start an image forming operation (S203). The developing roller travel distance calculation unit 1003 refers to the developer remaining amount TJ of the developer remaining amount detecting device 1004 for each predetermined developing roller travel distance Wu (S204). Then, the corrected developing roller travel distance Hu is calculated using the developing roller travel distance correction coefficient k and the environment correction coefficient z corresponding to the developer remaining amount TJ (S205). From the corrected development roller travel distance Hu and the cumulative corrected development roller travel distance Hr stored in the memory M, the total corrected development roller travel distance Ht is calculated (S206). After that, the developing roller remaining life GJ is calculated (S207). Then, it is determined whether the developing roller remaining life GJ is 0% or less (S208). If it has reached 0% or less, the accumulated corrected developing roller travel distance Hr is written in the memory M (S210), and the operation panel OP is notified that the life of the developing device 400 has been reached (S211). If it has not reached 0% or less, the cumulatively corrected developing roller travel distance Hr is written in the memory M (S209) and prepared for the next image formation.

  The life determination sequences S212 to S217 and S211 based on the remaining amount of developer in the developer remaining amount detection device 1004 are the same as the life determination sequences S111 to S116 and S110 based on the remaining amount of developer in Embodiment 1 (FIG. 3). Is omitted.

By executing this series of flowcharts, in the second embodiment, the travel distance W of the developing roller 401 is corrected using the developing roller travel distance correction coefficient k and the environmental correction coefficient z, and integrated, so that the lifetime of the developing device 400 is increased. Can be notified to the user. In the second embodiment, the detection result of the developer remaining amount detecting device 1004 is also used, and the fact that the developer T of the developing device 400 is almost gone is also notified.

  Further, the life warning threshold WL may be set before the developing roller travel distance threshold Wth reaches the development roller travel distance threshold Wth. That is, when the development roller travel distance Ht after the total cumulative correction reaches or exceeds the life warning threshold WL, control may be performed so as to issue a life warning of the developing device 400. Further, in Example 2, when the remaining developing roller life GJ reaches 0%, the life of the developing device 400 is determined. However, the developing roller remaining life GJ can be displayed on the operation panel OP each time the developing roller travel distance Ht after the total cumulative correction is updated.

<Specific example>
A specific example in which the second embodiment is applied more specifically will be described with reference to FIGS. 10 and 11. In Example 2, the environment correction coefficient z is set as shown in FIG. 10 according to the absolute moisture content of the environment in which the image forming apparatus is used. Here, the absolute water content = 1.06 represents an environment of temperature 15 ° C./humidity 10% Rh. In Example 2, printing was performed in an environment where the absolute water content was less than 1.06.

<Case 4>
Here, a case where the environmental correction coefficient z is applied to <Case 2> of the first embodiment will be described.
FIG. 11 shows the relationship between the remaining amount of developer TJ and the remaining life of the developing roller 401 when printing is performed using the image forming apparatus at a constant printing rate of about 1 to 2%. In the figure, the vertical axis represents the developer remaining amount TJ, and the horizontal axis represents the remaining life of the developing roller 401. In each zone, the same developing roller travel distance correction coefficient k as in the first embodiment is applied. In FIG. 11, the alternate long and short dash line indicates the transition of the developing roller remaining life GJ when the traveling distance W of the developing roller 401 is corrected using the developing roller traveling distance correction coefficient k and the environment correction coefficient z. In FIG. 11, the solid line shows the remaining life transition of the developing roller 401 when the travel distance W of the developing roller 401 is corrected without applying the environmental correction coefficient z. Further, as a comparative example, in FIG. 11, a broken line indicates the remaining life transition of the developing roller 401 when the travel distance W of the developing roller 401 is not corrected.

  In FIG. 11, the remaining amount of developer TJ is Zone 1 up to 40%, and the developing roller travel distance correction coefficient k1 = 1.0 and the environmental correction coefficient z1 = 1.2 are applied. Therefore, in Zone 1, the developing roller travel distance correction coefficient k = k1 × z1 = 1.0 × 1.2 = 1.2. Further, when the developer remaining amount TJ is 40% or later, Zone 2 is set, and the developing roller travel distance correction coefficient k2 = 1.7 and the environment correction coefficient z1 = 1.2 are applied. Therefore, in Zone 2, the developing roller travel distance correction coefficient k = k2 × z1 = 1.7 × 1.2 = 2.04.

For this reason, the developing roller remaining life GJ of the one-dot chain line indicates that the developing roller 401 advances in Zone 1 as compared with the case where the travel distance W of the developing roller 401 is corrected without applying the solid environment correction coefficient z. Apparently it is faster, and it is even faster from point B9. The solid line developing roller remaining life GJ was 0% at point A4, and the life of the developing device 400 was notified. Here, when the travel distance W of the developing roller 401 is corrected without applying the environmental correction coefficient z of the solid line, if printing is continued beyond the point B10, fogging due to filming of the developing roller 401, etc. In some cases, image defects may occur. Further, even when the travel distance W of the developing roller 401 indicated by the broken line is not corrected, if the printing is further continued beyond the point B11, image defects such as fogging due to filming of the developing roller 401 occur. Therefore, by correcting the travel distance W of the developing roller 401 using the developing roller travel distance environment correction coefficient z corresponding to the absolute water content, the occurrence of an image defect caused by the filming of the developing roller 401 is caused more than in the first embodiment. Can be avoided more reliably.

  As described above, the travel distance W of the developing roller 401 is corrected using the environment correction coefficient z corresponding to the absolute water content in addition to the development roller travel distance correction coefficient k corresponding to the remaining amount of the developer T. As a result, the optimum life of the developing device 400 can be notified. Particularly in an environment where filming of the developing roller 401 is likely to occur, the remaining amount of developer TJ in the developing device 400 is small, and the cumulative running distance of the developing roller 401 from the start of use of the process cartridge P is long. The optimum life of the developing roller 401 can be notified. In this case, a good image can be obtained without causing image degradation due to deterioration (filming) of the developing roller 401.

  In the second embodiment, the relationship between the absolute water content and the environment correction coefficient z as shown in FIG. 11 is used, but the present invention is not limited to this. It is also possible to subdivide the absolute water content more finely and use different environmental correction factors z. Moreover, you may utilize things other than an absolute water content as an parameter | index which shows a use environment for an environmental correction coefficient. For example, an environmental correction coefficient corresponding to the humidity detected by the temperature / humidity detection unit may be used. Further, for example, a temperature detection unit that detects the temperature in the atmospheric environment may be provided, and an environment correction coefficient may be acquired according to the temperature detected by the temperature detection unit.

<Example 3>
A third embodiment of the present invention will be described. Note that matters not described below are the same as those in the first and second embodiments. As shown in the first and second embodiments, when the travel distance W of the developing roller 401 is corrected using the developing roller travel distance correction coefficient k and the environment correction coefficient z, compared to the case where the correction is not performed, The traveling distance W of the developing roller 401 is apparently faster. In particular, when the point B6 or the point B7 as shown in FIG.

  Therefore, in the third embodiment, a case will be described in which correction is performed such that the developing roller remaining life GJ decreases at a constant rate. Note that the overall configuration of the image forming apparatus is the same as that of the first embodiment, and thus detailed description thereof is omitted.

  In the memory M of the process cartridge P, the development roller travel distance Hr after accumulation correction, the development roller travel distance threshold Wth, the development roller travel distance correction coefficient k, and the uncorrected development roller travel distance Wr before correction. , Is stored. The memory M also stores developer T usage information and lifetime information such as a cumulative video count value VCr and a video count threshold value VCth obtained by the developer remaining amount detection device 1004.

(Developing roller travel distance calculation device 1001)
Next, a developing roller travel distance calculating device 1001 that performs the remaining life% correction of the developing roller remaining life GJ, which is a feature of the third embodiment, will be described. The developing roller travel distance calculating device 1001 uses the developing roller travel distance measuring unit 1002 that measures the travel distance W of the developing roller 401 and the developing roller travel distance correction coefficient k to correct the travel distance W of the developing roller 401. A roller travel distance calculation unit 1003.

The developing roller travel distance measuring unit 1002 measures the travel distance W from the driving time Td of the developing device 400, the process speed Ps of the image forming apparatus, and the peripheral speed ratio Sr of the developing roller 401 to the photosensitive drum 100. Here, the travel distance W is the distance that a certain point on the surface of the developing roller 401 has advanced by the rotation of the developing roller 401. Further, the process speed Ps of the image forming apparatus is the rotational speed of the photosensitive drum 100. Specifically, the travel distance W of the developing roller 401 is obtained by the following calculation formula.
W = Td × Ps × Sr

The developing roller travel distance calculation unit 1003 first refers to the developer remaining amount TJ by the developer remaining amount detection device 1004 for each predetermined developing roller travel distance Wu measured by the developing roller travel distance measuring unit 1002. The developing roller travel distance correction coefficient k corresponding to the developer remaining amount TJ stored in the memory M is read out. In the third embodiment, the predetermined developing roller travel distance Wu is about two A4 sheets = 300 mm. The corrected developing roller travel distance Hu is calculated by multiplying the predetermined developing roller travel distance Wu by the development roller travel distance correction coefficient k. Specifically, the corrected developing roller travel distance Hu is obtained by the following calculation formula.
Hu = k × Wu

Next, the corrected development roller travel distance Hu is added to the cumulative correction development roller travel distance Hr from the start of use of the process cartridge P stored in the memory M, whereby the total cumulative correction development roller travel distance Ht. Is calculated. Specifically, it is obtained by the following calculation formula.
Ht = Hr + Hu
At this time, the developing roller travel distance calculation unit 1003 adds a predetermined developing roller travel distance Wu to the pre-accumulation development roller travel distance Wr from the start of use of the process cartridge P stored in the memory M, thereby obtaining a total. The developing roller travel distance Wt before correction is also calculated. The development roller travel distance Wt before total correction is the total travel distance when the life is reached when correction is not performed (the total uncorrected distance when the life is reached, the first distance).
Wt = Wr + Wu

Then, the developing roller remaining life GJ is calculated from the developing roller travel distance threshold Wth (predetermined threshold distance) stored in the memory M and the development roller travel distance Ht after total accumulation correction.
GJ [%] = (1-Ht / Wth) × 100
At the same time, the developing roller remaining life WGJ before correction is calculated from the developing roller travel distance threshold Wth stored in the memory M and the development roller travel distance Wt before total accumulation correction. The development roller remaining life WGJ before correction is an uncorrected remaining life (first remaining life) when the life is reached.
WGJ [%] = (1-Wt / Wth) × 100

  Then, the development roller travel distance Ht after the total cumulative correction is written in the memory M as the development roller travel distance Hr after the cumulative correction, and the development roller travel distance Wt before the total cumulative correction is written as the development roller travel distance Wr before the cumulative correction.

Here, in Zone 2 and Zone 3 shown in FIG. 6 of the first embodiment, as described above, the remaining of the developing roller 401 is obtained when the traveling distance W of the developing roller 401 is corrected and when it is not corrected. The way of life is different. Therefore, the developing roller remaining life GJ is corrected by estimating the developing roller remaining life WGJ before correction when the developing roller remaining life GJ reaches 0%. Specifically, a point where a straight line formed by the inclination of the developing roller remaining life WGJ before correction intersects with the developing roller life line GS shown in FIG. Remaining life WE. The developing roller remaining life WE before correction at the end of life is the ratio of the total uncorrected distance (second distance) at the time of determining the life to the developing roller travel distance threshold Wth. Life). That is, assuming that the horizontal axis in FIG. 7 is the x-axis and the vertical axis is the y-axis, the slope of the straight line connecting the current (during life determination) coordinates (x, y) and the y-intercept (0, 100) (current (Slope) is first calculated. Next, the slope of the straight line connecting (0, 100) and the point B5 (the slope of the point B5), the slope of the straight line connecting (0, 100) and the point B2 (the slope of the point B2), (0, 100) and the point The slope of the straight line connecting A1 (the slope of the point A1) is obtained. These 3
Compare the slope of one line with the current slope. For example, when the current inclination is between the inclination of the point B5 and the inclination of the point B2, the straight line of the current inclination intersects with the straight line connecting the points B5 and B2. Therefore, the intersection point between the current straight line and the straight line connecting points B5 and B2 is calculated. The x coordinate of the intersection is the developing roller remaining life WE before correction at the end of the life. The post-correction developing roller residual life HGJ is calculated using the pre-correction developing roller residual life WE at that time and the current pre-correction developing roller residual life WGJ.
HGJ [%] = {1- (100-WGJ) / (100-WE)} × 100

  Here, when the corrected developing roller remaining life HGJ = 100%, the developing device 400 is new. When the corrected developing roller remaining life HGJ = 0%, the developing device 400 has reached the end of its life and the process cartridge P is in the replacement period.

(Developing device 400 life determination sequence)
FIG. 12 is a sequence chart for determining the life of the developing device 400 according to the third embodiment. The control unit 1000 can detect the life of the developing device 400 and notify the user of the detection result by performing each process shown in the flowchart of FIG. 12 based on the information in the memory M of the process cartridge P. .

  First, when a print signal is sent to the image forming apparatus (S301), the developing device 400 is driven to start an image forming operation (S302). The developing roller travel distance calculation unit 1003 refers to the developer remaining amount TJ of the developer remaining amount detecting device 1004 for each predetermined developing roller travel distance Wu (S303). Then, the corrected developing roller travel distance Hu is calculated using the developing roller travel distance correction coefficient k corresponding to the developer remaining amount TJ (S304). From the corrected development roller travel distance Hu and the corrected corrected development roller travel distance Hr stored in the memory M, the total corrected development roller travel distance Ht is calculated (S305). Further, the pre-correction developing roller travel distance Wt and the pre-correction development roller travel distance Wt stored in the memory M are calculated (S306). Thereafter, the developing roller remaining life GJ and the corrected developing roller remaining life WGJ are calculated (S307). Then, when the developing roller remaining life GJ reaches 0%, the developing roller remaining life WE before the correction at the lifetime is estimated (S308). Thereafter, the post-correction developing roller residual life HGJ is calculated using the pre-correction developing roller residual life WE and the pre-correction developing roller residual life WGJ at that time (S309). Next, it is determined whether the corrected developing roller remaining life HGJ is 0% or less (S310). If it has reached 0% or less, the development roller travel distance Hr after cumulative correction and the development roller travel distance Wr before cumulative correction are written in the memory M (S313). Thereafter, the operation panel OP provided in the image forming apparatus is notified that the developing device 400 has reached the end of its life (S314). If it has not reached 0% or less, the development roller travel distance Hr after cumulative correction and the development roller travel distance Wr before cumulative correction are written in the memory M (S311). Then, the corrected developing roller remaining life HGJ at that time is displayed on the operation panel OP (S312), and in preparation for the next image formation.

  The life determination sequences S315 to S320 and S314 based on the remaining amount of developer in the developer remaining amount detection device 1004 are the same as the life determination sequences S111 to S116 and S110 (FIG. 3) based on the remaining amount of developer in the first embodiment. Is omitted.

By executing this series of flowcharts, in the third embodiment, the development roller remaining life GJ is corrected by estimating the developing roller travel distance WE before correction at the time of life, and the life of the developing device 400 is notified. I can do it. Further, in the third embodiment, as in the first and second embodiments, the detection result of the developer remaining amount detection device 1004 is also used together to notify that the developer T of the developing device 400 is almost gone. did. In this way, not only the life of the developing device 400 due to the deterioration (filming) of the developing roller 401 but also the life of the developing device 400 due to the remaining amount of the developer T can be notified, and a more optimal life of the developing device 400 can be reported. Can be notified to the user.

  Further, the life warning threshold WL may be set before the developing roller travel distance threshold Wth reaches the development roller travel distance threshold Wth. That is, when the development roller travel distance Ht after the total cumulative correction reaches or exceeds the life warning threshold WL, control may be performed so as to issue a life warning of the developing device 400. For example, when the lifetime notice threshold WL is set to be 90% of the developing roller travel distance threshold Wth, when the remaining life GJ of the developing roller 401 reaches 10%, the lifetime of the developing device 400 is near to the user. It becomes possible to alert | report the warning of being. Therefore, the user can prepare for the replacement of the process cartridge P in advance.

<Specific example>
A specific example in which the third embodiment is applied more specifically will be described with reference to FIG. The developing roller travel distance correction coefficient k used in the third embodiment is the same as that shown in the first embodiment.

<Case 5>
Here, a case where the remaining life% correction of the developing roller remaining life GJ is applied to <Case 2> of the first embodiment will be described.
FIG. 13 shows the relationship between the remaining amount of developer TJ and the remaining life of the developing roller 401 at the time when printing is performed using the image forming apparatus at a constant printing rate of about 1 to 2%. In the figure, the vertical axis represents the developer remaining amount TJ and the remaining life of the developing roller 401. In each zone, the same developing roller travel distance correction coefficient k as in the first embodiment is applied. In FIG. 13, the solid line shows the transition of the remaining developing roller life GJ when the traveling distance W of the developing roller 401 is corrected using the developing roller traveling distance correction coefficient k in <Case 2> of the first embodiment. Yes. In FIG. 13, the broken line indicates the remaining life transition of the developing roller 401 when the travel distance W of the developing roller 401 is not corrected in <Case 2> of the first embodiment. In FIG. 13, the alternate long and two short dashes line indicates the corrected developing roller remaining life HGJ obtained by performing the remaining life% correction of the developing roller 401 with respect to <Case 2> of Example 1 of the solid line.

  In FIG. 13, as described in the first embodiment, the developing roller remaining life GJ indicated by the solid line changes in inclination from the point B1 where the developer remaining amount TJ = 40%, and the traveling distance W of the developing roller 401 advances. Is apparently faster. That is, the progress of the developing roller remaining life GJ changes between point B1 and point B1. Therefore, when the solid developing roller remaining life GJ reaches 0% (point A2), a point on the developing roller life line GS at which the developing roller remaining life WGJ before broken line reaches is estimated, that is, the point B2. Then, assuming that the developing roller remaining life WGJ before correction at the point B2 is 0%, the current developing roller remaining life WGJ before correction is calculated. This is the corrected developing roller remaining life HGJ indicated by a two-dot chain line. The corrected developing roller remaining life HGJ reaches the remaining life of 0% at the point A2 without bending in the middle and changing in advancing manner, that is, without changing suddenly in the middle. At that time, the operation panel OP is notified that the developing device 400 has reached the end of its life.

  As described above, the remaining life% of the developing roller remaining life GJ is corrected by using the developing roller remaining life WGJ before correction, so that the remaining life% of the developing roller 401 does not change abruptly. The lifetime of the device 400 can be notified. As a result, a good image can be obtained without causing image damage due to deterioration (filming) of the developing roller 401.

  DESCRIPTION OF SYMBOLS 400 ... Developing apparatus, 401 ... Developing roller, 1001 ... Developing roller traveling distance calculation apparatus, 1002 ... Developing roller traveling distance measurement part, 1003 ... Developing roller traveling distance calculation part, 1004 ... Developer remaining amount detection apparatus, 1005 ... Video count Measuring unit, 1006... Developer remaining amount calculating unit

Claims (10)

An image forming apparatus for forming an image on a recording material,
An image carrier that carries a developer image transferred to a recording material;
A developing device comprising: a developer carrying member that carries a developer for forming the developer image; and a developer container that contains a developer supplied to the developer carrying member;
A remaining amount acquisition unit for acquiring the amount of developer accommodated in the developer container;
A coefficient acquisition unit that acquires a correction coefficient according to the amount of developer contained in the developer container;
Whenever the travel distance of the developer carrier increases by a predetermined distance, a correction distance obtained by correcting the predetermined distance by the correction coefficient is obtained, and a total correction distance obtained by integrating the correction distance is obtained. And
A life determination unit that determines that the developing device has reached the end of its life when the total correction distance acquired by the correction distance acquisition unit exceeds a predetermined threshold;
An image forming apparatus comprising:   The life determination unit has a developer amount acquired by the remaining amount acquisition unit equal to or less than a predetermined threshold remaining amount even when the total correction distance acquired by the correction distance acquisition unit does not exceed a predetermined threshold. The image forming apparatus according to claim 1, wherein the image forming apparatus determines that the developing device has reached the end of its life. The remaining amount acquisition unit
A first acquisition method for acquiring a usage amount of a developer in forming the image from information of an image formed on a recording material, and acquiring an amount of the developer stored in the developer container based on the usage amount;
The developer using a light source that irradiates light inside the developer accommodating portion of the developer container and a light receiving portion that receives the light that has passed through the interior, and based on a change in a light receiving state of the light receiving portion A second acquisition method for acquiring the amount of developer contained in the container; and
Using an electrode whose electrostatic capacity that is detected in accordance with a change in the state of the developer in the inside, an amount of the developer stored in the developer container is acquired based on the change in the electrostatic capacity. 3 acquisition methods,
The image forming apparatus according to claim 1, wherein an amount of the developer stored in the developer container is acquired using at least one of the above.   When the amount of developer acquired by the first acquisition method becomes equal to or less than a second predetermined threshold remaining amount, the remaining amount acquisition unit performs either the second acquisition method or the third acquisition method. The image forming apparatus according to claim 3, wherein an amount of the developer stored in the developer container is acquired.   5. The remaining amount acquiring unit acquires the amount of developer at every time interval that travels the predetermined distance or a plurality of times within the time that travels the predetermined distance. The image forming apparatus according to claim 1.   The correction coefficient corresponding to the amount of developer accommodated in the developer container is characterized in that the amount of developer is divided into a plurality of ranges, and one correction coefficient is assigned to one section. The image forming apparatus according to claim 1.   The image forming apparatus according to claim 6, wherein the correction coefficient is constant within one of the sections. A temperature / humidity detection unit for detecting temperature / humidity in the atmospheric environment of the image forming apparatus, or a temperature detection unit for detecting temperature in the atmospheric environment;
An environmental correction coefficient according to the absolute moisture content or humidity acquired based on the temperature and humidity, or an environmental coefficient acquisition unit for acquiring an environmental correction coefficient according to the temperature;
Further comprising
The correction distance acquisition unit acquires a correction distance obtained by correcting the predetermined distance with the correction coefficient and the environmental correction coefficient each time the travel distance increases by the predetermined distance, and adds up the correction distance. The image forming apparatus according to claim 1, wherein a correction distance is acquired. The life determination unit
When determining whether the developing device has reached the end of its life,
The first distance is acquired as the total uncorrected distance at the end of life, which is the travel distance of the developer carrying member that has not been corrected at the end of life when the total corrected distance reaches the predetermined threshold,
Obtaining a first remaining life as an uncorrected remaining life at the end of the life, which is a ratio of the first distance to a predetermined threshold distance;
The second distance is acquired as the total uncorrected distance at the time of life determination, which is the travel distance of the developer carrier that has not been corrected at the time of life determination,
The second remaining life is obtained as an uncorrected remaining life at the time of life determination, which is a ratio of the second distance to the predetermined threshold distance,
The image forming apparatus according to claim 1, wherein the remaining life of the developing device when correction is performed is acquired using the first remaining life and the second remaining life. apparatus. When there is a first amount and a second amount greater than the first amount in the amount of developer contained in the developer container,
The image forming apparatus according to claim 1, wherein the correction coefficient corresponding to the first amount is smaller than the correction coefficient corresponding to the second amount.

Images