Developing device, process cartridge, and image forming apparatus

Abstract

To reduce the harmful effect on an image due to deteriorated toner that is a concern in recycling, to improve recyclability.SOLUTION: An image forming apparatus has: calculation means that acquires information on the use of a developer supply member, and calculates the life of the developer supply member by using the information; a storage unit that stores first information being information that a developing unit is a new item and second information being information that the developing unit is a recycled item; a driving unit that drives to rotate the developer supply member; and a control unit that controls the driving unit to execute a first rotation operation and a second rotation operation different from the first rotation operation on the basis of the information stored in the storage unit. When the information stored in the storage unit is the first information, the control unit controls the driving unit to execute the first rotation operation, and when the information stored in the storage unit is the second information, controls the driving unit to execute the second rotation operation.SELECTED DRAWING: Figure 10

Description

[Technical Field]

[0001] The present invention relates to an image forming apparatus that uses an electrophotographic recording method, such as a laser printer, a copier, or a facsimile. The image forming apparatus forms an image on a recording medium using an image forming process, such as an electrophotographic process, an electrostatic recording process, or a magnetic recording process. Examples of the image forming apparatus include copiers, printers (such as LED printers and laser beam printers), facsimile machines, word processors, and multifunction machines thereof. [Background technology]

[0002] Image forming apparatuses, such as electrophotographic image forming apparatuses, and cartridges used in such image forming apparatuses are, for example, process cartridges, developer cartridges, or drum cartridges that are removable from the main body of the image forming apparatus. Taking the aforementioned process cartridge as an example, it is a cartridge that integrates an image carrier on which a latent image is formed and at least one of a charging means, a developing means, a cleaning means, or the like, which serves as an image forming process means that acts on the image carrier. This type of cartridge configuration allows users to easily install and remove it from the main body of the image forming apparatus, making it a widely used technology because it facilitates maintenance of the image forming apparatus.

[0003] In recent years, recycling has become popular, with the aim of collecting used developer cartridges, process cartridges, etc., and reusing their components. When recycling, it is common to determine whether the components of the developer cartridges or process cartridges should be disposed of or whether they can be reused.

[0004] A technology is known in which the control performed when starting to use such a recycled cartridge is different from the control performed when starting to use a new cartridge. Patent Document 1 discloses a control that changes the pre-rotation time when starting to use a recycled developer cartridge based on the serial number of the developer cartridge and the result of toner remaining amount detection. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-139712 Summary of the Invention [Problem to be solved by the invention]

[0006] However, Cited Document 1 has the following problems. Conventionally, supply rollers that are made conductive by adding an ionic conductive agent to a urethane sponge have been known and widely used. When such conductive supply rollers are used in recycled cartridges, there are concerns that the following problems may occur. Mixing of deteriorated toner contained inside the supply roller with fresh toner at the time of recycling can cause image defects such as toner dripping and fogging. Furthermore, if the color of the toner used changes before and after recycling, the toner inside the supply roller and the refilled toner can mix, resulting in a change in color.

[0007] The present invention has been made in view of the above problems, and aims to improve recyclability. [Means for solving the problem]

[0008] In order to achieve the above object, the image forming apparatus of the present invention comprises: An image forming apparatus for forming an image on a recording material, a rotatable photoreceptor; a developing unit including: a developer carrier that is rotatably provided, that contacts the surface of the photosensitive member to form a developing section, and that supplies developer to the surface of the photosensitive member in the developing section; and a developer supply member that is rotatably provided, that contacts the surface of the developer carrier, and that supplies developer to the surface of the developer carrier; a calculation unit that acquires information regarding the use of the developer supply member and calculates the life of the developer supply member using the information; a storage unit that stores first information indicating that the developing unit is new and second information indicating that the developing unit is a recycled product; a drive unit that rotates the developer supply member; a control unit that controls the drive unit to perform a first rotation operation and a second rotation operation different from the first rotation operation based on information stored in the storage unit, The control unit controls the memory unit to perform the first rotation operation when the information stored in the memory unit is the first information, and controls the memory unit to perform the second rotation operation when the information stored in the memory unit is the second information. [Effects of the Invention]

[0009] As explained above, it is possible to improve recyclability. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a schematic configuration diagram of an image forming apparatus according to a first embodiment. [Figure 2] FIG. 2 is a control block diagram of the image forming apparatus according to the first embodiment. [Figure 3] FIG. 2 is a schematic functional block diagram of a control unit according to the first embodiment. [Figure 4] 1 is a flowchart showing an outline of a procedure for detecting the end of life in the first embodiment. [Figure 5] 5 is a flowchart showing an outline of detection of remaining toner amount in the first embodiment. [Figure 6] 10 is a diagram showing detection of the life of the developing roller in the first embodiment. [Figure 7] 1 shows the results of verification 1 in Example 1. [Figure 8] FIG. 10 is a detailed flowchart of calculating the life span of the supply roller in the first embodiment. [Figure 9]FIG. 3 is a timing chart showing a transition of a supply voltage in the first embodiment. [Figure 10] 10 is a detailed flowchart at the start of use in the first embodiment. [Figure 11] 4 is a timing chart showing the transition of the supply voltage when a new product is detected in the first embodiment. FIG. [Figure 12] 10 is a timing chart showing the transition of the supply voltage when detecting that the life span is 60% or more in the first embodiment. FIG. [Figure 13] 10 is a timing chart showing the transition of the supply voltage when detecting that the life span is 30% or more in the first embodiment. FIG. [Figure 14] 10 is a timing chart showing the transition of the supply voltage when it is detected that the lifespan is less than 30% in the first embodiment. FIG. [Figure 15] FIG. 10 is a schematic configuration diagram of an image forming apparatus according to a second embodiment. [Figure 16] 10 is a detailed flowchart at the start of use in the second embodiment. [Figure 17] 10 is a timing chart showing the transition of the supply voltage when detecting that the lifespan is 60% or more in Example 2 and when the toner before and after recycling is different. [Figure 18] 10 is a timing chart showing the transition of the supply voltage when detecting that the lifespan is 30% or more and when the toner before and after recycling is different in Example 2. [Figure 19] 10 is a timing chart showing the transition of the supply voltage when it is detected that the lifespan is less than 30% in Example 2 and the toner before and after recycling is different. DETAILED DESCRIPTION OF THE INVENTION

[0011] [Example 1] <Outline of image forming device> Referring to FIG. 1, the overall configuration and image forming operation of an electrophotographic image forming apparatus (hereinafter referred to as an image forming apparatus) of the first embodiment will be described. FIG. 1 is a cross-sectional view showing a schematic configuration of an image forming apparatus 100. As part of the image forming process, the image forming apparatus 100 has a rotatable photosensitive drum 1 (image carrier) that carries a toner image. The surface of the photosensitive drum 1 is made of an organic photosensitive material. A charging roller 2 charges the surface of the photosensitive drum 1 before forming a latent image. An exposure device 3 exposes the charged portion of the surface of the photosensitive drum 1 to form a latent image. A developing device 4 supplies a developer to the photosensitive drum 1 and visualizes the latent image formed and carried on the surface of the photosensitive drum 1 using the developer. A transfer roller 20 is rotatably supported and transfers the visualized image formed and carried on the surface of the photosensitive drum 1 to a recording material 50, which serves as a sheet-like recording medium, to form an unfixed image. The recording medium 50 is transported by a transport roller 59.

[0012] The fixing device 30 performs a fixing process on the recording medium 50, fixing and recording the unfixed image on the recording medium 50. The cleaning device 40 removes and collects residues on the surface of the photosensitive drum 1 after the transfer process, in preparation for the next latent image formation.

[0013] Next, we will explain the details of each part.

[0014] The photosensitive drum 1 is rotated at a predetermined process speed (204 mm / sec). A charging roller 2 is biased toward the photosensitive drum 1 by a pressure spring (not shown) and is pressed against the surface of the photosensitive drum 1 with a predetermined pressing force (500 g force).

[0015] The surface of the photosensitive drum 1 is uniformly charged by the charging roller 2. In the first embodiment, the charging roller 2 is a conductive roller having a conductive rubber layer provided on a metal core, and is disposed in parallel with the photosensitive drum 1 in contact with it at a predetermined pressure, rotating as the photosensitive drum 1 rotates. A charging voltage can be applied to the charging roller 2 from a high-voltage power supply 224, which serves as a power supply means. In the first embodiment, the photosensitive drum 1 is charged by applying a DC voltage of, for example, -1150 V to the charging roller 2, and the surface potential of the photosensitive drum 1 at this time is approximately -500 V. The voltage applied to the charging roller 2 is not limited to a DC voltage; an AC voltage can also be applied and controlled at a constant current.

[0016] An exposure device 3, which is an exposure unit, scans a laser beam corresponding to an image signal over the surface of the photosensitive drum 1. As a result, an electrostatic latent image corresponding to the image signal is formed on the charged surface of the photosensitive drum 1. The image signal is input in response to a request from a user, for example, from an image reading device (not shown) connected to the image forming apparatus main body, or from a host device (not shown) such as a personal computer connected to the image forming apparatus main body so as to be able to communicate with the image forming apparatus main body.

[0017] The developing device 4, which serves as a developing unit, deposits toner 90, charged with the same polarity as the charge polarity of the photosensitive drum 1, onto portions (image portions, exposed portions) of the surface of the photosensitive drum 1 where the charge has decayed due to exposure, thereby forming a toner image, which is a developer image. In the first embodiment, the developing device 4 contains toner 90 as a non-magnetic single-component developer, for example, whose normal charge polarity (the charge polarity for developing an electrostatic latent image) is negative. The developing device 4 includes a rotatable developing roller 42, which serves as a developer carrier; a supply roller 43, which has a rotatable roller shape and serves as a developer supply member; and a regulating blade 44, which serves as a regulating member. The developing roller 42 contacts the photosensitive drum 1 to form a developing section, and supplies the toner 90, charged with the normal charge polarity, to the photosensitive drum 1 in the developing section. The recording medium 50 bearing the unfixed image is subjected to a fixing process by the fixing device 30, and the unfixed image is fixed and recorded on the recording medium 50. The fixed recording medium 50 is then ejected from the image forming apparatus 100.

[0018] After the transfer process, any residue remaining on the surface of the photosensitive drum 1 is removed and collected by the cleaning device 40, and the photosensitive drum 1 is prepared for the next latent image formation.

[0019] The cleaning device 40 is equipped with a cleaning blade 12 having urethane rubber fixed to the tip of a blade-shaped metal plate, and is installed so as to contact the surface of the photosensitive drum 1 at a contact angle of 24° and a contact pressure of 50 g / cm, rubbing against the surface of the photosensitive drum 1. The cleaning blade 12 removes residue from the surface of the photosensitive drum 1 after the transfer process and collects it inside the cleaning device 40. In this embodiment, the material of the cleaning blade 12 that contacts the photosensitive drum 1 is urethane rubber, but the material is not limited to this and may be any polymeric rubber elastic body such as chloroprene rubber, ethylene propylene diene rubber, or nitrile rubber.

[0020] In the developing device 4, toner 90 is supplied to the surface of the developing roller 42 by a supply roller 43. The toner 90 held on the developing roller 42 (on the developer carrier) is then thinned by a regulating blade 44, which regulates the layer thickness (hereinafter referred to as "layer thickness"). The regulating blade 44 not only regulates the layer thickness of the toner 90 on the developing roller 42, but also functions as a developer charging means that imparts a predetermined charge to the toner 90 on the developing roller 42. The thinned toner 90 is transported to the contact portion with the photosensitive drum 1 as the developing roller 42 rotates, and develops the electrostatic latent image formed on the surface of the photosensitive drum 1. Furthermore, toner 90 that is not used for development and remains on the developing roller 42 is removed from the developing roller 42 at the contact portion with the supply roller 43. The removed toner 90 is then stirred and mixed with the toner 90 in the developing device 4.

[0021] The developing roller 42 has a conductive elastic rubber layer with a predetermined volume resistivity provided on the outer periphery of a metal core, and the surface of the developing roller 42 is further provided with a predetermined surface roughness. The developing roller 42 can be a single-layer roller or a roller with a multi-layer configuration. A single-layer roller is one in which an elastic layer made of a rubber material such as silicone rubber, urethane rubber, or hydrin rubber is formed on a core. A multi-layer roller is one in which a surface layer is formed by coating the surface of an elastic layer with a material such as silicone resin, urethane resin, polyamide resin, or fluororesin. In the first embodiment, in order to obtain an appropriate image density, the developing roller 42 is rotated at a speed such that the moving speed of the surface of the developing roller 42 is, for example, 130% of the moving speed of the surface of the photosensitive drum 1.

[0022] The supply roller 43 is an elastic sponge roller with a conductive foam formed on the outer periphery of a metal core. The supply roller 43 is disposed so as to contact the developing roller 42 with a predetermined penetration depth. Here, the penetration depth refers to the penetration depth of the developing roller 42 into the outer diameter of the supply roller 43. In Example 1, the supply roller 43 has a urethane foam layer and contains an ionic conductive agent. As an example, the supply roller 43 of Example 1 is configured such that an ionic conductive agent composed of a salt of a cation and an anion having a reactive functional group that reacts with an isocyanate group is chemically bonded to the urethane foam layer via the reactive functional group. For example, a supply roller 43 with such a configuration can be manufactured by foaming and curing a urethane composition containing an ionic conductive agent. By forming the urethane surface layer into an open-cell structure, toner can be contained within the toner supply roller 43, enabling stable toner supply to the surface of the developing roller 42. Note that the resistance of the supply roller 43 in this example is 1×10 7The resistance of the supply roller 43 is measured in Ω (Ω). The method for measuring the resistance of the supply roller 43 is described below. The supply roller 43 is placed in contact with an aluminum sleeve with a diameter of 30 mm, with a penetration depth of 1.5 mm. By rotating the aluminum sleeve, the supply roller 43 is driven to rotate at 30 rpm relative to the aluminum sleeve. Next, a DC voltage of −50 V is applied to the developing roller 42. A 10 kΩ resistor is placed on the ground side, and the current is calculated by measuring the voltage across the resistor, thereby calculating the resistance of the supply roller 43. In this embodiment, the surface cell diameter of the supply roller 43 is set to 50 μm to 1000 μm. Here, the cell diameter refers to the average diameter of foam cells in an arbitrary cross section. First, the area of ​​the largest foam cell is measured from an enlarged image of the arbitrary cross section, and this area is converted into a diameter equivalent to a perfect circle to obtain the maximum cell diameter. Foam cells that are half or less of this maximum cell diameter are then eliminated as noise, and the average cell diameter is calculated in the same manner from the remaining individual cell areas. In this example, the cell diameter of the supply roller 43 was measured using a laser microscope, a shape measuring laser microscope (manufactured by Keyence Corporation, model number: VK-X200).

[0023] The regulating blade 44 has a plate-like elastic member that is conductive and flexible. One end of the elastic member is fixed to the developer container (frame) and supported as a cantilever, and the other end is a free end that abuts against the circumferential surface of the developing roller 42. The regulating blade 44 is disposed in contact with the circumferential surface of the developing roller 42 at a position downstream of the opposing portion (contact portion) of the supply roller 43 and the developing roller 42 in the moving direction (rotation direction) of the surface of the developing roller 42. In Example 1, a stainless steel material is used as the elastic member of the regulating blade 44. In Example 1, the regulating blade 44 is disposed such that, at the contact position with the developing roller 42, the tip end of the free end of the elastic member faces upstream in the moving direction of the surface of the developing roller 42 (counter direction).

[0024] Furthermore, a predetermined DC voltage is applied to the developing roller 42, the supply roller 43, and the regulating blade 44 from a high-voltage power supply 224 (first power supply, second power supply) as a power supply device in accordance with the image forming operation, etc. In the first embodiment, a voltage is applied according to the temperature and humidity of the image forming apparatus. In an environment of 23°C, a DC voltage of −350 V is applied to the developing roller 42, −450 V to the supply roller 43, and −450 V to the regulating blade 44. Since the normal charge polarity of the toner 90 in the first embodiment is negative, the potential difference between the supply roller 43 and the developing roller 42 is a polarity that urges (moves) the toner 90 from the supply roller 43 side toward the developing roller 42 side. In this embodiment, the potential difference between the supply roller 43 and the developing roller 42 is variably controlled according to the usage environment and the degree of deterioration of the supply roller 43. This control stabilizes the supply of toner 90 from the supply roller 43 to the developing roller 42.

[0025] On the other hand, the potential difference between the regulating blade 44 and the developing roller 42 has a polarity that urges the toner 90 from the regulating blade 44 side toward the developing roller 42 side. This stabilizes the intake of the toner into the contact area between the regulating blade 44 and the developing roller 42, and also stabilizes the application of the electric charge to the toner 90 by the regulating blade 44.

[0026] In Example 1, toner 90 was a negatively charged non-magnetic toner produced by suspension polymerization. However, the toner is not limited to this, and toner produced by other polymerization methods, such as pulverization or emulsion polymerization, may also be used. The volume average particle size of toner 90 is preferably 5.0 to 8.0 μm. The volume average particle size of the toner was measured using a Multisizer 3 precision particle size distribution analyzer manufactured by Beckman Coulter, Inc. In Example 1, the volume average particle size of toner 90 was approximately 7.0 μm.

[0027] In Example 1, all four toners 90Y, 90M, 90C, and 90K are toner particles containing a release agent and an organosilicon polymer on the surface of the toner particles. 1 / 2The toner has a T3 unit structure represented by the formula (3), where R represents an alkyl group or phenyl group having 1 to 6 carbon atoms, and the organosilicon polymer forms convex portions on the surface of the toner base particles. This creates a spacer effect between the toner base particle surface and components such as the developing roller 42, reducing adhesion. The convex portions are also characterized by surface contact with the toner base particle surface, which is expected to significantly inhibit the migration, detachment, and embedding of the convex portions. Therefore, even in a configuration in which the developing roller 42 is driven while spaced apart from the photosensitive drum 1, long-term use is possible. While Example 1 used toner 90 particles containing an organosilicon polymer on the toner base particle surface, this is not limited to this, and toner particles that do not contain an organosilicon polymer on the toner base particle surface may also be used.

[0028] Toner 90 may also contain additives (hereinafter referred to as external additives), such as a fluidizing agent and a cleaning aid, in order to improve fluidity, chargeability, cleaning properties, and the like.

[0029] Examples of external additives include inorganic oxide particles such as silica particles, alumina particles, and titanium oxide particles; inorganic stearic acid compound particles such as aluminum stearate particles and zinc stearate particles; and inorganic titanic acid compound particles such as strontium titanate and zinc titanate. These can be used alone or in combination of two or more. These inorganic particles are preferably gloss-treated with a silane coupling agent, a titanium coupling agent, a higher fatty acid, a silicone oil, or the like to improve heat-resistant storage stability and environmental stability. The BET specific surface area of ​​the external additive is 10 m 2 / g or more 450m 2 / g or less is preferable.

[0030] The BET specific surface area can be determined by a low-temperature gas adsorption method using a dynamic constant pressure method in accordance with the BET method (preferably the BET multipoint method). For example, a specific surface area measuring device (trade name: Gemini 2375 Ver. 5.0, manufactured by Shimadzu Corporation) is used to adsorb nitrogen gas onto the surface of a sample, and the BET multipoint method is used to measure the BET specific surface area (m 2 / g) can be calculated.

[0031] The total amount of these various external additives added is 0.05 to 5 parts by mass, preferably 0.1 to 3 parts by mass, per 100 parts by mass of toner. Various external additives may be used in combination.

[0032] <Process cartridge> In this embodiment, the image forming apparatus 100 has a photosensitive drum 1, a drum unit 62 in which a charging roller 2 and a cleaning device 40, which serve as process means acting on the photosensitive drum 1, are integrated, and a developing device 4. The drum unit 62 and the developing device 4 are collectively configured as a cartridge (integrated process cartridge) 10 that can be detachably attached to a predetermined attachment portion of the image forming apparatus 100.

[0033] When the process cartridge 10 is mounted in the mounting portion within the image forming apparatus 100, the drive and electrical contacts on the cartridge 10 side are connected to a high-voltage power supply 224, which is a drive and voltage output portion of the image forming apparatus 100. As a result, the drive force of the drive source on the image forming apparatus 100 side is transmitted to the cartridge 10 side, driving the photosensitive drum 1 and the developing roller 42, supply roller 43, and agitating member 55 of the developing device 4. In addition, a voltage is applied from the high-voltage power supply 224 on the image forming apparatus 100 side to the process cartridge 10 side, applying a charging voltage to the charging roller 2 and a developing voltage to the developing roller 41.

[0034] <Storage information in non-volatile memory> The process cartridge 10 is equipped with a nonvolatile memory 8 as a storage unit. The nonvolatile memory 8 stores a flag (first information) that determines whether the developing device 4 is new. In this embodiment, "new" refers to an unused state, such as having never been installed in the image forming apparatus 100 and used for image formation, or having never been installed in the image forming apparatus 100. A recycle flag (second information) can also be stored to determine whether the developing device 4 is a recycled product. In this embodiment, "recycled product" refers to a state in which a developing device has been installed in the image forming apparatus 100 and used for image formation, but can be used again as if it were new, for example, by refilling toner. Alternatively, it refers to a state in which a component once reached the end of its life and became unusable, but the component that reached the end of its life was replaced with a new component or a component in usable condition, making it usable again. Both of these information are stored in the nonvolatile memory 8 during the manufacture of the process cartridge. When a new developing container is manufactured, a new flag is stored, and when a recycled cartridge is manufactured, a recycle bit is stored. The new product flag and the recycle bit are not limited to the information on new product and recycle product themselves, as long as they are different information from each other.

[0035] The nonvolatile memory 8 of the process cartridge 10 also stores information about the usage status of the developing device 4, such as the cumulative surface travel distance of the developing roller 42, the image dot cumulative value, and the degree of deterioration of the supply roller 43 (described later). Other information stored and updated as needed is the amount of toner used, the lifespan of the photosensitive drum 1, the number of sheets of recording paper S on which an image has been recorded, and other information. The nonvolatile memory 8 also stores threshold information for calculating various lifespans, such as the cumulative image dot cumulative value, the number of sheets of recording paper S on which an image has been recorded, the cumulative surface travel distance of the developing roller 42, the amount of remaining toner, and the deterioration threshold of the supply roller 43. Other information specific to the process cartridge 10 is also stored, such as a system program for controlling the image forming apparatus, various adjustment values, the serial number of the apparatus, and system data indicating the date of manufacture.

[0036] <Control block diagram> The control configuration of the image forming apparatus 100 will be described with reference to the block diagram of FIG.

[0037] The main body controller 201 shown in FIG. 2 includes a control unit 220 (central processing unit) as a control means that is a central element for performing arithmetic processing. It also includes a main body memory 221, such as a ROM and RAM, as a storage means, and an input / output interface (I / F) 222 for inputting and outputting information to and from peripheral devices. The ROM of the main body memory 221 stores control programs, such as a program for calculating the lifespan of the supply roller 43 and a program for calculating the remaining toner amount, as described below. The control unit 220 is a control means that comprehensively controls the operation of the image forming apparatus 100, and each control target in the image forming apparatus 100 is connected to the input / output I / F 222. The control unit 220 controls the transmission and reception of various electrical information signals and drive timing, and is responsible for the processing of the flowcharts described below. The motor drive unit 223 refers to various motors, and is a power source for rotating and driving the polygon scanner, photosensitive drum 1, developing roller 42, supply roller 43, etc., inside the scanner unit 3. It operates based on control signals from the control unit 220. The high-voltage power supply 224 is a power supply that applies high voltage to the photosensitive drum 1, charging roller 2, developing roller 42, supply roller 43, transfer roller 20, fixing device 30, etc. The temperature and humidity sensor 225 is a sensor for detecting the temperature and humidity of the environment in which the image forming apparatus 100 is used, and is used to change control in accordance with the detected temperature and humidity. The nonvolatile memory 8 of the process cartridge 10 is connected to the main body controller 201 via a memory communication unit 226, and is capable of reading and writing information. In this embodiment, a non-contact non-volatile memory is used as the storage means, but other appropriate memory devices may be used, such as a contact non-volatile memory, a non-contact non-volatile memory, or a volatile memory with a power source.

[0038] <Process cartridge replacement life> - Overview of detecting the life of the developing device - Next, detection of the lifespan of the developing device 4 (process cartridge 10) in this embodiment will be described. In this embodiment, the developing device 4 is replaceable as part of the process cartridge 10, and so the lifespan of the developing device 4 means the lifespan of the process cartridge 10. Here, although it is sometimes simply referred to as "lifespan of the developing device 4" or "replacement of the developing device 4," in this embodiment they are equivalent to "lifespan of the process cartridge 10" and "replacement of the process cartridge 10," respectively. Needless to say, this can also be applied to a configuration in which only the developing device 4 is replaceable.

[0039] Fig. 3 is a schematic functional block diagram of the control unit 220 related to detecting the end of life of the developing device 4 in this embodiment. In this embodiment, each functional block shown in Fig. 3 is realized by the control unit 220 executing a program stored in the main body memory 221. Fig. 4 is a flowchart showing an outline of the procedure for detecting the end of life of the developing device 4 in this embodiment.

[0040] In this embodiment, the control unit 220 has a toner remaining amount detection unit 70, a developing roller life detection unit 60, and a supply roller life detection unit 80 as functional blocks for detecting the life of the developing device 4. The toner remaining amount detection unit 70 is configured to include a first video count measurement unit 71 and a toner remaining amount calculation unit 72. The developing roller life detection unit 60 is configured to include a developing roller surface movement distance calculation unit 61. The supply roller life detection unit 80 is configured to include a supply voltage application time calculation unit 81, a supply voltage measurement unit 82, a second video count measurement unit 83, and a supply roller deterioration level calculation unit 84. Details of the toner remaining amount detection unit 70, the developing roller life detection unit 60, and the supply roller life detection unit 80 will be described later.

[0041] Here, an outline of the procedure for detecting the life of the developing device 4 will be described using FIG. 4. When a print signal (job information) is input (S101), the control unit 220 starts a print operation (job) (S102). Then, at a predetermined timing (e.g., during the post-rotation process) during the print operation (job execution), the control unit 220 determines whether the developing device 4 has reached the end of its life (S103-S105). Specifically, in this embodiment, the control unit 220 determines whether the remaining toner amount TJ (%) in the developing device 4 has reached a predetermined threshold value (e.g., 0%) (S103). It also determines whether the remaining developing roller life GJ (%) has reached a predetermined threshold value (e.g., 0%) (S104) and whether the remaining supply roller life ηJ (%) has reached a predetermined threshold value (e.g., 0%) (S105). The remaining toner amount TJ is determined by the toner remaining amount detection unit 70. The remaining developing roller life GJ is determined by the developing roller life detection unit 60. The remaining supply roller life ηJ is determined by the supply roller life detection unit 80. Specific methods for this will be described later.

[0042] If the control unit 220 determines that none of the remaining toner amount TJ, the remaining life of the developing roller GJ, and the remaining life of the supply roller ηJ have reached the predetermined threshold (S103: NO, S104: NO, S105: NO), the control unit 220 terminates the print operation (S106). This is because it can be determined that the developing device 4 has not reached the end of its life. On the other hand, if the control unit 220 determines that any one of the remaining toner amount TJ, the remaining life of the developing roller GJ, and the remaining life of the supply roller ηJ has reached the predetermined threshold (YES in at least one of S103, S104, and S105), the control unit 220 performs the following control: Executes a process to notify the user of information regarding the life (replacement) of the developing device 4 (S107). This is because it can be determined that the developing device 4 has reached the end of its life and needs to be replaced. Specifically, in this embodiment, the control unit 220 controls the operation unit 160 of the image forming apparatus 100 and the display unit of the external device 300 to display information regarding the life (replacement) of the developing device 4. This display may simply indicate that the developing device 4 has reached the end of its life, or may be a display urging the user to replace the developing device 4. Then, the control unit 220 ends the printing operation (S106).

[0043] In Figure 4, the detection of the life of the developing device 4 based on the remaining toner amount TJ, the remaining life of the developing roller GJ, and the remaining life of the supply roller ηJ is shown to be performed in this order, but these may be performed in parallel or in an order different from that shown in Figure 4.

[0044] Furthermore, it is also possible to notify independently that the remaining toner amount TJ, the remaining life of the developing roller GJ, and the remaining life of the supply roller ηJ have reached a predetermined threshold (no toner, the life of the developing roller 42, or the life of the supply roller 43). In this case, it is possible to simply notify that there is no toner remaining or that the developing roller 42 or the supply roller 43 has reached the end of its life, or to notify that the developing device 4 needs to be replaced due to each of these causes (prompting the user to replace the developing device 4).

[0045] Furthermore, for example, assuming the reuse of components of the developing device 4, information regarding the degree of deterioration of the developing roller 42 and the supply roller 43 is acquired and stored in the memory 221, but it is also possible not to detect or notify the end of the life of the developing device 4 based on this information. This information can be read from the memory 221 during the regeneration and reuse process of the developing device 4, and used to determine whether or not the developing roller 42 and the supply roller 43 can be reused.

[0046] -Detecting remaining toner- Next, detection of the remaining amount of toner in the developing device 4 in this embodiment will be described. Fig. 5 is a flowchart showing an outline of the procedure for detecting the end of life of the developing device 4, focusing on detection of the remaining amount of toner. The process according to the flowchart in Fig. 5 is executed by the control unit 220 (mainly the remaining toner amount detection unit 70).

[0047] In this embodiment, the control unit 220 detects (calculates) the remaining toner amount in the toner remaining amount detection unit 70, with the aim of prompting the user to replace the developing device 4 when the remaining toner amount is low. In this embodiment, the toner remaining amount detection unit 70 employs a video counting method (or a pixel counting method) as a developer remaining amount detection method. The video counting method (or a pixel counting method) is a method of obtaining information regarding the number of pixels in the printed portion of an image by counting laser exposure ON signals (signals that cause the laser to emit light, pixel signals) generated based on image data. Although the video counting method is employed in this embodiment, a known toner remaining amount detection means that detects parameters that are correlated with the physical properties of the toner may also be employed.

[0048] When a print signal (job information) is input (S201), the control unit 220 starts a print operation (job) (S202). At a predetermined timing during the print operation (e.g., during the post-rotation process), the first video count measurement unit 71 receives pixel information of an image to be formed and output on the recording material 50 (hereinafter also referred to as an "output image") (S203) and measures a video count value VCn, which is the number of pixel signals (S204). In this embodiment, the first video count measurement unit 71 acquires pixel information of all images in the print operation (job) contained in the print signal and measures a video count value VCn of all images. This video count value VCn correlates with the amount of toner 90 used to form images in the print operation (job).

[0049] Next, the remaining toner amount calculation unit 72 calculates a total video count value VCt, which is the cumulative value of the video count value since the start of use of the developing device 4 (process cartridge 10) (S205). That is, as shown in equation (1), the remaining toner amount calculation unit 72 adds (integrates) the video count value VCn measured by the first video count measurement unit 71 to the cumulative video count value VCr since the start of use of the developing device 4, which is stored in the memory 221. In this way, the total video count value VCt is calculated. VCt = Vcr + VCn (1) Next, the remaining toner amount calculation unit 72 calculates the remaining toner amount TJ in the developing device 4 using the video count threshold value VCth that is set in advance and stored in the memory 221 and the calculated total video count value VCt, using the following equation (2) (S206). TJ[%]=(1-VCt / VCth)×100···(2) As described above, the remaining toner amount calculation unit 72 updates the calculated total video count value VCt as a new cumulative video count value VCr and stores it in the memory 221 (S207). The remaining toner amount calculation unit 72 may also update the calculated remaining toner amount TJ and store it in the memory 221.

[0050] Here, when the toner remaining amount TJ=100%, the toner 90 in the developing device 4 is full, and the developing device 4 is brand new at the start of use. When the toner remaining amount TJ≦0%, the toner 90 in the developing device 4 is almost gone, and it is time to replace the developing device 4. In other words, when the toner remaining amount TJ≦0%, the total video count value VCt has reached the video count threshold value VCth, and the developing device 4 has reached the end of its life.

[0051] Therefore, the control unit 220 determines whether the remaining toner amount TJ calculated by the remaining toner amount calculation unit 72 is 0% or less (S208). If the control unit 220 determines in S208 that the remaining toner amount TJ is not 0% or less, it ends the printing operation (S209). On the other hand, if the control unit 220 determines in S208 that the remaining toner amount TJ is 0% or less, it controls to execute a process to notify the user of information related to the life of the developing device 4 (S210). Then, the control unit 220 ends the printing operation (S209).

[0052] In this embodiment, the first video count measurement unit 71 measures the video count value VCn for each print operation (job), but it may also be configured to measure, for example, the number of pixel signals of an image for one sheet of recording material 50 as one video count value VCn. Also, in this embodiment, the toner is considered to be full when the toner remaining amount TJ=100%, but it is also possible to use the toner consumption amount as a reference and consider 0% to be full.

[0053] -Detecting the life of the developing roller- Next, detection of the lifespan of the developing roller 42 in this embodiment will be described. Fig. 6 is a flowchart outlining the procedure for detecting the lifespan of the developing device 4, focusing on detection of the lifespan of the developing roller 42. The processing according to the flowchart in Fig. 6 is executed by the control unit 220 (mainly the developing roller lifespan detection unit 60).

[0054] In this embodiment, the remaining life of the developing roller 42 is detected (calculated) by the developing roller life detection unit 60 in order to prompt the user to replace the developing device 4 when the developing roller 42 has deteriorated. In this embodiment, the remaining life of the developing roller 42 is detected (calculated) based on the surface movement distance (rotation distance, rotation speed, etc.) of the developing roller 42. As the surface movement distance increases, the developing roller 42 deteriorates due to an increase in electrical resistance and contamination by deposits, and so it is known that there is a lifespan that corresponds to the surface movement distance.

[0055] When a print signal (job information) is input (S301), the control unit 220 starts a print operation (job) (S302). During the print operation, the developing roller surface movement distance calculation unit 61 calculates a total developing roller surface movement distance Ht for each predetermined developing roller surface movement distance Hu (S303). That is, as shown in the following equation (3), the developing roller surface movement distance calculation unit 61 adds (integrates) Hu to the cumulative developing roller surface movement distance Hr stored in the memory 221 for each predetermined developing roller surface movement distance Hu. In this way, the total developing roller surface movement distance Ht is calculated. Ht = Hr + Hu (3) Next, the developing roller surface movement distance calculation unit 61 calculates the remaining life GJ of the developing roller using the developing roller surface movement distance threshold Hth, which is set in advance and stored in memory 221, and the calculated total developing roller surface movement distance Ht, using the following equation (4) (S304). GJ[%]=(1-Ht / Hth)×100···(4) Furthermore, the developing roller surface movement distance calculation unit 61 updates the calculated total developing roller surface movement distance Ht as a new cumulative developing roller surface movement distance Hr and stores it in the memory 221 (S305). The developing roller surface movement distance calculation unit 61 may also update the calculated developing roller remaining life GJ and store it in the memory 221.

[0056] Here, when the developing roller remaining life GJ=100%, it indicates that the developing device 4 is brand new at the start of use. When the developing roller remaining life GJ≦0%, it indicates that it is time to replace the developing device 4. In other words, when the developing roller remaining life GJ≦0%, the total developing roller surface movement distance Ht has reached the developing roller surface movement distance threshold Hth, and the developing device 4 has reached the end of its life.

[0057] Therefore, the control unit 220 determines whether the developing roller remaining life GJ calculated by the developing roller surface movement distance calculation unit 61 is 0% or less (S306). If the control unit 220 determines in S306 that the developing roller remaining life GJ is not 0% or less, it ends the print operation (S307). On the other hand, if the control unit 220 determines in S306 that the developing roller remaining life GJ is 0% or less, it controls to execute a process to notify the user of information related to the life of the developing device 4 (S308). Then, the control unit 220 ends the print operation (S307).

[0058] -Detecting the life of the supply roller- In this embodiment, the supply roller life detection unit 80 detects (calculates) the remaining life of the supply roller 43 in order to prompt the user to replace the developing device 4 when the supply roller 43 deteriorates. The detection of the life of the supply roller 43 in this embodiment will be explained in detail after explaining the mechanism of deterioration of the supply roller 43.

[0059] <Deterioration of supply roller> - Supply roller deterioration mechanism - Next, deterioration of supply roller 43 will be described. In this embodiment, the material of urethane foam layer 43b of the elastic sponge roller constituting supply roller 43 contains an ion conductive agent. Supply roller 43 having such a configuration is preferably used from the viewpoints of production stability and cost. According to the study by the present inventors, deterioration of supply roller 43 having such a configuration can be broadly classified into two types.

[0060] The first type of deterioration of the supply roller 43 is deterioration due to the passage of current through the supply roller 43. This mechanism of deterioration of the supply roller 43 is well known. As mentioned above, the supply roller 43 is given electrical conductivity by adding an ionic conductive agent during manufacturing. Generally, when a voltage of the same polarity is continuously applied to a material having ionic conductivity, the ionic conductive agent becomes unevenly distributed, reducing the number of ions dispersed within the material capable of transporting electrons compared to the initial state, resulting in an increase in electrical resistance. In this embodiment, a potential difference is established between the supply roller 43 and the developing roller 42 such that the potential of the supply roller 43 is more negative than the potential of the developing roller 42. In other words, in this embodiment, a voltage of a negative polarity is applied to the supply roller 43 relative to the developing roller 42. When such a voltage is continuously applied to the supply roller 43 of this embodiment, the ionic conductive agent tends to migrate to the inside of the supply roller 43 (toward the core metal) and become unevenly distributed. This uneven distribution of the ionic conductive agent progresses in correlation with the applied voltage value and application time. Therefore, it is possible to predict the degree of deterioration of the supply roller 43 due to energization from the value and duration of the voltage applied to the supply roller 43 .

[0061] The second type of deterioration of the supply roller 43 is deterioration due to a decrease in the ionic conductive agent in the supply roller 43. Conventionally, no efforts have been made to acquire information on the degree of deterioration of the supply roller 43 while focusing on this second mechanism of deterioration. The toner contained in the urethane foam layer 43b of the supply roller 43 is replaced successively during rotation of the supply roller 43. The inventors' research has confirmed that the ionic conductive agent in the urethane foam layer 43b electrically adheres to the charged toner and is removed from the urethane foam layer 43b as the toner moves from the supply roller 43 to the developing roller 42. This phenomenon is particularly pronounced when the print rate of the output image is high and the amount of toner moving from the supply roller 43 to the developing roller 42 increases. This phenomenon causes the amount of ionic conductive agent in the urethane foam layer 43b of the supply roller 43 to decrease compared to the initial state. As a result, the electrical resistance of the supply roller 43 increases, and its sensitivity to the applied voltage decreases, reducing its ability to supply toner to the developing roller 42.

[0062] As the supply roller 43 deteriorates, image defects such as poor solid image tracking may occur, as described above.

[0063] -Verification 1: Effect of electrical degradation- Tests were conducted to examine the effects of degradation due to energization of the supply roller 43. The following print endurance tests were conducted under conditions of a supply voltage Vrs of -450V and -650V. The development voltage Vdc was set to -350V in both cases. The electrical resistance of the supply roller 43 was measured at predetermined intervals. Here, the current flowing through the supply roller 43 when a predetermined voltage was applied to the supply roller 43 was measured as a proxy for the supply roller 43's electrical resistance. Continuous operation without toner consumption eliminates the effects of conductive agent reduction, described below. For the print endurance test, continuous printing of images with a print rate of 0% was performed in the operating environment (ambient environment) of the image forming apparatus 100, which was a temperature of 15°C and a humidity (relative humidity) of 10%. Setting the print rate to 0% eliminates the effects of reduced electrical resistance due to the conductive agent carried away by the toner, described below.

[0064] The results are shown in FIG. 7(a). The vertical axis represents the rate of decrease in current value when the initial current value (a substitute for electrical resistance value) is set to 100%, and the horizontal axis represents the rotational drive time of the supply roller 43 (= supply voltage application time). As shown in FIG. 8(a), the decrease in current value (the increase in electrical resistance value) tends to be greater when the supply voltage Vrs is −650 V than when the supply voltage Vrs is −450 V. This is because the ionic conductive agent contained in the supply roller 43 moves and becomes unevenly distributed due to continuous current flow. As such, it can be seen that a larger supply voltage Vrs (i.e., the potential difference between the supply voltage Vrs and the development voltage Vdc) causes a larger amount of movement of the ionic conductive agent, resulting in a larger increase in the electrical resistance value of the supply roller 43.

[0065] - Verification 2: Differences in the amount of toner contained in the supply roller depending on the printing rate - A test was conducted to examine the difference in the amount of toner contained in the supply roller 43 depending on the printing rate. The following print durability test was conducted under two conditions: a printing rate of 0% and a printing rate of 100%. The amount of toner contained in the supply roller 43 was measured at predetermined intervals. The amount of toner contained in the supply roller 43 was calculated from the difference between the weight of a supply roller 43 that did not contain toner (unused) and the weight of the supply roller 43 at each interval. For the print durability test, intermittent printing of one sheet was performed in the operating environment (ambient environment) of the image forming apparatus 100, which was a temperature of 23°C and a humidity of 50%. The supply voltage Vrs was −450 V, and the development voltage Vdc was −350 V. Note that N-sheet intermittent printing refers to a printing method in which a printing operation is performed in which images are continuously formed on N sheets of recording material 50, the operation is temporarily stopped, and then a printing operation is performed again in which images are continuously formed on N sheets of recording material 50. This operation is repeated.

[0066] The results are shown in Figure 7(b). The vertical axis represents the amount of toner contained in the supply roller 43, and the horizontal axis represents the number of prints. As shown in Figure 7(b), throughout the print durability test, there was a difference in the amount of toner held on the supply roller 43 between the condition of a 0% print rate and the condition of a 100% print rate (less toner held on the supply roller 43 when the print rate was 100% than when the print rate was 0%). This is because when the print rate of the output image is high, the amount of toner moving from the development roller 42 to the photosensitive drum 1 increases, and therefore the amount of toner supplied from the supply roller 43 to the development roller 42 also increases. The overall decrease in the amount of toner contained in the supply roller 43 as the number of prints increases is due to, among other things, the decrease in the amount of toner supplied to the supply roller 43 as the amount of toner in the development device 4 decreases.

[0067] -Verification 3: Impact of reduced conductive agent- A test was conducted to examine the difference in the amount of conductive agent reduction depending on the printing rate. The following print durability test was conducted under two conditions: a 1% printing rate and a 100% printing rate. Measurements were also conducted to evaluate the amount of conductive agent components contained in the supply roller 43 at predetermined timings. The amount of conductive agent components was evaluated by measuring the current flowing through the supply roller 43 when a predetermined voltage was applied to the supply roller 43. If the current value decreased, applying a voltage of the opposite polarity to the predetermined voltage did not increase (recover) the current value by the amount of the decrease, thereby confirming that the amount of conductive agent components had been reduced. For the print durability test, intermittent printing of one sheet was conducted in the operating environment (ambient environment) of the image forming apparatus 100, which was a temperature of 23°C and humidity of 50%. The supply voltage Vrs was set to -450V, and the development voltage Vdc was set to -350V.

[0068] The results are shown in Figure 7(c). The vertical axis represents the rate of decrease in current value when the initial current value (a proxy value for the amount of conductive agent component) is set to 100%, and the horizontal axis represents the rotational drive time of the supply roller 43 (= the time during which the supply voltage is applied). It can be seen that the decrease in current value (the decrease in the amount of conductive agent) tends to be greater under conditions of a high print rate (100%) than under conditions of a low print rate (1%). This is because when the print rate is high and the amount of toner replacement within the supply roller 43 per unit time is large, a larger amount of conductive agent is discharged from the developing device 4 along with the toner during printing than when the print rate is low. As such, it can be seen that the decrease in the amount of conductive agent is greater when the print rate is high than when the print rate is low. In this invention, the deterioration level of the supply roller 43 is calculated taking into account the characteristics of the supply roller 43 discovered by the inventors.

[0069] In other words, the phenomenon of the conductive agent added to the material of the foamed elastic layer of the supply roller 43 decreasing is more pronounced when a high-print-ratio image is formed and toner consumption is high, compared to when a low-print-ratio image is formed and toner consumption is low. Therefore, the degree of deterioration of the supply roller 43 varies depending on the usage conditions of the image forming apparatus 100 by the user. Therefore, it is desirable to obtain information regarding the degree of deterioration of the supply roller 43 more accurately depending on the usage conditions of the image forming apparatus 100.

[0070] Furthermore, in recent years, from the viewpoint of usability, a toner supply system has been adopted in which only the toner container can be separated from the developing device 4 (process cartridge 10) and replaced. In such a configuration, the supply roller 43 is required to have higher durability, and the supply roller 43 often has a longer lifespan. Therefore, in such a configuration, there is a possibility that the timing at which the supply roller 43 reaches the end of its lifespan will vary greatly depending on the degree of deterioration of the supply roller 43 depending on the user's usage of the image forming apparatus 100. Therefore, in such a configuration, it is even more necessary to obtain more accurate information regarding the degree of deterioration of the supply roller 43 depending on the user's usage so that the developing device 4 can be replaced at the appropriate time.

[0071] <Calculating the degree of deterioration of the supply roller (detecting the end of the supply roller's life)> Next, detection of the lifespan of the supply roller 43 (calculation of the deterioration level of the supply roller 43) in this embodiment will be described. Fig. 8 is a flowchart outlining the procedure for detecting the lifespan of the developing device 4, focusing on detection of the lifespan of the supply roller 43. The process according to the flowchart in Fig. 8 is executed by the control unit 220 (mainly the supply roller lifespan detection unit 80). Fig. 9 is a timing chart showing the transition of the supply voltage Vrs applied to the supply roller 43 during a printing operation in this embodiment.

[0072] In this embodiment, the supply roller life detection unit 80 detects (calculates) the remaining life of the supply roller 43 in order to prompt the user to replace the developing device 4 when the supply roller 43 deteriorates. In this embodiment, the degree of deterioration of the supply roller 43 is calculated for each print operation (job) taking into account the voltage value of the supply voltage Vrs (or the potential difference between the supply voltage Vrs and the developing voltage Vdc), the application time of the supply voltage Vrs, and the print rate of the output image. The deterioration degree of the supply roller 43 is then added up for each print operation (job), and when a predetermined deterioration level is reached, information regarding the life of the developing device 4 is notified to the user. That is, in this embodiment, the supply roller life detection unit 80 detects (calculates) the remaining life of the supply roller 43 based on the voltage value of the supply voltage Vrs (or the potential difference between the supply voltage Vrs and the developing voltage Vdc), the application time of the supply voltage Vrs, and the print rate of the output image.

[0073] When a print signal (job information) is input (S401), the control unit 220 starts the print operation (job) (S402). Furthermore, with the start of the print operation, the control unit 220 acquires the detection result of the temperature and humidity sensor 130 (S403) and determines the supply voltage Vrs based on the detection result (particularly, temperature in this embodiment) of the temperature and humidity sensor 130 (S404). The supply voltage Vrs applied to the supply roller 43 by the power supply 123 is measured and controlled by the supply voltage measurement unit 82. In this embodiment, the control unit 220 reads and determines the supply voltage Vrs corresponding to the temperature from table data shown in Table 1, which is preset and stored in the main body memory 221. The table data in Table 1 is an example of information indicating the relationship between the environment and the supply voltage Vrs.

[0074] [Table 1]

[0075] Subsequently, during the printing operation, the supply voltage application time calculation unit 81 measures the time for which the supply voltage Vrs is applied to the supply roller 43 (S405), and calculates the supply voltage application time tnow for the printing operation (S406). If the supply voltage application start timing for the printing operation is tS and the supply voltage application end timing for the printing operation is tE, the supply voltage application time tnow for the printing operation can be expressed by the following formula (5). tnow=tE-tS···(5) Furthermore, at a predetermined timing during the printing operation (e.g., during the post-rotation process), the second video count measurement unit 83 receives pixel information of the output image and calculates the section printing rate γnow, which is the printing rate for the printing operation, based on the measured video count value VCn (S407). In this embodiment, the second video count measurement unit 83 acquires pixel information for all images in the printing operation (job) contained in the print signal and measures the video count value VCn for all images. The second video count measurement unit 83 then calculates the section printing rate γnow for all images. Note that the printing rate (image printing rate, image ratio) indicates the area ratio (proportion) of the printed area, where 100% is the area where all pixels in the image formation area (area where a toner image can be formed) are printed. The printing rate for all images in the printing operation can be expressed as the area ratio (proportion) of the printed area for all images, where the total number of pixels in all images is the total pixel count. Then, the supply roller deterioration level calculation unit 84 determines the deterioration correction coefficient ε based on the section printing rate γnow acquired by the second video count measurement unit 83 (S408). In this embodiment, the supply roller deterioration level calculation unit 84 reads and determines the deterioration correction coefficient ε corresponding to the section printing rate γnow from table data shown in Table 2, which is set in advance and stored in the memory 221. The table data in Table 2 is an example of information indicating the relationship between the printing rate and the deterioration correction coefficient ε.

[0076] [Table 2]

[0077] Next, the supply roller deterioration level calculation unit 84 calculates the section supply roller deterioration level ηnow, which is an index showing the degree of deterioration of the supply roller 43 in the print operation, using the following formula (6) (S409). ηnow=tnow×|Vrs|×ε···(6) Next, the supply roller deterioration level calculation unit 84 calculates a total supply roller deterioration level ηt, which is an index showing the degree of deterioration of the supply roller 43 since the start of use of the developing device 4 (supply roller 43) (S410). That is, as shown in the following formula (7), the supply roller deterioration level calculation unit 84 adds (integrates) the calculated section supply roller deterioration level ηnow to the cumulative supply roller deterioration level ηr since the start of use of the developing device 4 (supply roller 43), which is stored in the memory 221. In this way, the total supply roller deterioration level ηt is calculated. Then, the supply roller deterioration level calculation unit 84 updates the calculated total supply roller deterioration level ηt with the calculated total supply roller deterioration level ηt and stores it in the memory 221 as a new cumulative supply roller deterioration level ηr. ηt=ηnow+ηr (7) Next, the supply roller deterioration level calculation unit 84 calculates the supply roller remaining life ηJ from the supply roller deterioration level threshold ηth, which is preset and stored in the memory 221, and the calculated total supply roller deterioration level ηt, using the following formula (8) (S411). The supply roller deterioration level threshold ηth is determined in advance through experiments or the like so that image defects such as poor solid image tracking do not occur even when the toner remaining amount is 0%. The supply roller deterioration level threshold ηth may vary depending on, for example, the elastic material constituting the foamed elastic layer of the supply roller 43, the type and amount of conductive agent contained in the material of the foamed elastic layer, the type of toner 90, and the like. The supply roller deterioration level calculation unit 84 may update and store the calculated supply roller remaining life ηJ in the memory 221. ηJ[%]=(1-ηt / ηth)×100 (8) Here, when the supply roller remaining life ηJ=100%, it indicates that the developing device 4 is brand new. When the supply roller remaining life ηJ≦0%, it indicates that it is time to replace the developing device 4. When the supply roller remaining life ηJ≦0%, the total supply roller deterioration level ηt has reached the supply roller deterioration level threshold value ηth, and the developing device 4 has reached the end of its life.

[0078] Therefore, the control unit 220 determines whether the supply roller remaining life ηJ calculated by the supply roller deterioration level calculation unit 84 is 0% or less (S412). If the control unit 220 determines in S412 that the supply roller remaining life ηJ is not 0% or less, it ends the print operation (S413). On the other hand, if the control unit 220 determines in S412 that the supply roller remaining life ηJ is 0% or less, it controls to execute a process to notify the user of information related to the life of the developing device 4 (S414). Then, the control unit 220 ends the print operation (S413).

[0079] While FIG. 9 shows the calculation of the supply voltage application time tnow and the calculation of the section printing rate γnow (and the determination of the deterioration correction coefficient ε) performed in parallel, these may be performed sequentially, and the order in which they are performed is arbitrary. In this embodiment, the section printing rate γnow (and the deterioration correction coefficient ε), the section supply roller deterioration degree ηnow, and the total supply roller deterioration degree ηt are calculated for each print operation (job) at a predetermined timing (e.g., during the post-rotation process) during the print operation (during job execution). However, the present invention is not limited to this, and these may be calculated sequentially at predetermined timings during the print operation. For example, the supply voltage application time tnow, the section printing rate γnow (and the deterioration correction coefficient ε), the section supply roller deterioration degree ηnow, and the total supply roller deterioration degree ηt may be calculated each time an image is formed. Furthermore, for example, each time the section supply roller deterioration degree ηnow increases by a predetermined value, the ηnow may be added (integrated) to the cumulative supply roller deterioration degree ηr stored in memory 221 to calculate the total supply roller deterioration degree ηt. If the supply roller remaining life ηJ becomes 0% or less during a print operation (job), a process may be executed to notify the user of information regarding the life of the developing device 4, and the print operation may be terminated (interrupted). This also applies to the remaining toner amount TJ and the remaining development roller life GJ described above. This also applies to other embodiments described later.

[0080] Note that cartridge life detection is not limited to the method of detecting the remaining amount of developer described above. In an all-in-one process cartridge 10, the life of the photosensitive drum 1 can also be detected. The film thickness of the photosensitive layer (charge generating layer) of the photosensitive drum 1 decreases over time. Therefore, a suitable means for detecting drum life (cartridge life) is a means for determining drum life by detecting an increase in the current value when a constant voltage is applied to the photosensitive drum 1. Alternatively, a suitable means for determining life may be used, such as a means for calculating the drum film thickness from a deterioration coefficient according to the user's usage conditions and determining the life.

[0081] In addition to detecting the drum life, cartridge life can be detected by various means, such as detecting by comparing the cumulative number of sheets of paper passed (cumulative number of images formed) with a predetermined threshold value, or, in the case of a drum cleaner, detecting by comparing the amount of waste toner accumulated in the waste toner storage section with a predetermined threshold value.

[0082] <Recycled form> The recycling method for the process cartridge 10 in this embodiment will now be described. Used cartridges removed from the image forming apparatus 100 by the user based on a lifespan forecast or lifespan warning for the process cartridge 10 are collected at a recycling plant. If the components (image forming process members) of the collected used cartridge are recyclable, the cartridge is disassembled in a recycling process and the recyclable components are extracted. These are then regenerated as necessary and reused as components for new cartridges. In this embodiment, the new cartridges described above are defined as recycled products.

[0083] Here, when a component part of a used cartridge is recyclable, it means that even if it is reused as a component part of a new cartridge, it will be in a state where it will not cause image defects during use throughout the guaranteed life of the cartridge. Furthermore, with regard to the determination of whether or not to recycle, at least in this embodiment, it is possible to determine recycling based on the life of the supply member. This is because, as mentioned above, depending on the user's usage history, the usable life of the supply member may be shorter than that of other parts.

[0084] In the present invention, the collected process cartridge 10 is disassembled into the developing container 4 and the drum unit 62. The disassembled developing container 4 is cleaned to remove the toner 90 remaining inside. In this embodiment, to reduce the load during recycling, the developer regulating member and the supply member are not removed from the developing container, and air is blown from the top surface (not shown) of the developing container 4 to remove the toner 90 remaining inside.

[0085] It should be noted that the means for cleaning the inside of the developing container is not limited to the above cleaning, and for example, it is also possible to remove the developing roller 42 and clean the inside of the developing container with an air gun or the like while leaving the supply roller 43 attached to the developing container 4. Similarly, it is also possible to remove all of the developing roller 42, supply roller 43, and developer regulating member 44 from the developing container 4 and clean the inside of the container.

[0086] In either case, in the recycling process after cleaning, the recyclable supply roller 43 is assembled as is into the developer container 4, and the container is filled with toner 90 again. In addition, a new recycling bit is stored in the nonvolatile memory 8, and the life of the supply member 43 at the time of recycling is also stored in the nonvolatile memory 8.

[0087] <Risks when reusing recycled developer containers> Next, we will discuss the risks involved in reusing the recycled developer container in this embodiment. This embodiment is a so-called monochrome developer container, and the toner used before and after recycling is the same color. A risk when starting to use this recycled developer container is that degraded toner remaining inside the supply member and newly filled toner may aggregate, resulting in image defects such as toner dripping and fogging. Research by the inventors has shown that the toner contained inside the supply roller at the time of recycling is accumulated with degraded toner. Degraded toner here refers to toner with a high degree of irregularity, toner cracks, or toner in a parent state with external additives peeled off. Such toner has significantly different chargeability and fluidity from new toner when refilled. These differences can cause the toner to aggregate, forming clumps, resulting in streaks, and image defects such as toner dripping and fogging. This problem becomes more pronounced when the container is refilled with some residual toner remaining after cleaning during recycling. For this reason, when a recycled developer container is first used, it is desirable to discharge the toner remaining in the supply member out of the developer container. In this embodiment, discharge control is performed during the control at the start of use. It has also been found that this discharge control is also affected by the degree of deterioration of the supply member. That is, in order to move the toner inside the supply roller to the developing roller, not only physical contact but also potential difference is important. As the deterioration of the supply roller progresses, it becomes necessary to increase the applied voltage to obtain the potential difference necessary to move the toner. In this embodiment, taking these factors into consideration, a feature is that the applied voltage to the supply member and the discharge time are optimized according to the degree of deterioration of the supply member. In this way, by optimizing the initial control when recycling and reusing, recycling can be achieved with a simple cleaning process.

[0088] <Selective control of start-up sequence> Next, a detailed description will be given of the start-up control at the start of use of the developing container, which is a feature of the present invention. In this embodiment, the feature of this proposal is that the control is switched depending on the new product flag as the first information stored in advance in the nonvolatile memory 8, the recycle flag as the second information, and the life of the supply roller 43. This makes it possible to perform optimal start-up control depending on the degree of deterioration of the supply roller.

[0089] FIG. 10 shows a detailed flowchart of the start-up process in this embodiment. First, the image forming apparatus 1 is powered on (S501). At that time, the control unit 220 checks whether or not there is a new product flag in the non-volatile memory 8 (S502). If the control unit 220 detects the new product flag, it executes start-up control by the first rotation operation for a new SQ (S503), as shown in FIG. 11. After execution, the apparatus enters a print-ready state (S504) and a job standby state.

[0090] The purpose of the initial control in this case is to loosen the toner in the developing container and rotate it to improve circulation.

[0091] Next, if the control unit 220 does not detect the new product flag in (S502), it checks whether or not there is a recycle bit (S505). If the control unit 220 detects the recycle bit, it checks whether the life of the supply roller is 60% or more (S506). If the life of the supply roller is 60% or more, the control unit 220 executes start-of-use control by recycle SQ(A) as the second rotation operation shown in FIG. 12 (S507). Thereafter, the printer enters a print-ready state (S504) and a job standby state.

[0092] The purpose of the initial control in this case is to loosen the toner in the developing container, rotate the roller to improve circulation, and efficiently expel the toner from inside the supply roller 43. Because the supply roller is in a state where it has little deterioration, the applied voltage required for expelling the toner can be kept low.

[0093] Next, in (S506), if the lifespan of the supply roller is less than 60%, the control unit 220 checks whether the lifespan of the supply roller is 30% or more (S508). If the lifespan of the supply roller is less than 60% but greater than 30%, the control unit 220 executes start-of-use control using recycle SQ (B) as the second rotation operation shown in Fig. 13 (S509). Thereafter, the printer enters the print-ready state (S504) and waits for a job.

[0094] The purpose of the initial control in this case is to loosen the toner in the developer container, rotate the roller to improve circulation, and efficiently expel the toner from inside the supply roller. Because the supply roller is in an advanced state of deterioration, the frequency of expulsion is increased as shown in Figure 12, and the amount expelled is increased to suppress contamination. In other words, the execution time of the second rotation operation is increased.

[0095] If the control unit 220 determines in (S508) that the life of the supply roller is less than 30%, it executes start-of-use control using the recycle SQ (C) as the second rotation operation shown in Fig. 14 (S510). After that, it enters the print ready (S504) state and waits for a job. If the control unit 220 does not detect the recycle bit in (S505), it enters the print ready (S504) state and waits for a job.

[0096] The purpose of the initial control in this case is to loosen the toner in the developer container, rotate the roller to improve circulation, and efficiently expel the toner from inside the supply roller. Because the supply roller is in a deteriorated state, the frequency of expelling the toner is increased and the applied voltage during expelling is strengthened to compensate for the decrease in the amount of toner expelled due to the deterioration of the supply roller.

[0097] In this way, the amount of toner discharged is controlled to be increased according to the life of the supply member, and a proper image can be obtained without causing contamination between the durable toner remaining on the supply member and the newly filled toner.

[0098] <Comparative verification> In order to verify the effect of initial discharge of toner from a recycled developer container in the configuration of an embodiment of the present invention, verification was carried out using this embodiment and the following comparative example.

[0099] <Evaluation method> The effect of the control is confirmed by preparing recycled developer containers with different supply roller lifespans.

[0100] Specifically, a developing machine having the following configuration was prepared. i) Recycled developer container with supply roller life of 75% ii) A recycled developer container with a supply roller life of 35% iii) Recycled developer container with supply roller life of 15% The developing containers i) to iii) above were subjected to an image output test in an environment of a temperature of 23° C. and a relative humidity of 50%.

[0101] Then, the occurrence of image defects was evaluated for each evaluation developer. In this evaluation, the image defects were evaluated by visually judging and evaluating density unevenness in halftone image printing according to the following criteria. ○: No uneven density ×: Conspicuous unevenness in density occurs, causing practical problems [Comparative Example 1] The control at the start of use is the same as that when the product is new.

[0102] Comparative Example 2 This is a control that repeats the new product control twice, assuming a conventional example, with the aim of extending the rotation time at the start of use.

[0103] The results are shown in Table 3 below.

[0104] [Table 3]

[0105] In the conventional control, the degree of deterioration of the supply roller is not taken into consideration, so if the start control after recycling is not performed appropriately, the residual toner inside the supply roller and the newly replenished toner will electrostatically aggregate, resulting in poor images. On the other hand, in the control of the present invention, the discharge control at the start of use that corresponds to the deterioration of the supply member is selected, so it was confirmed that stable images can be obtained without suppressing the occurrence of poor images at the start of use of the recycled developer container.

[0106] As described above, in the present invention, the discharge control at the start of use is selected in response to deterioration of the supply member, so that it is possible to provide the user with stable images without image defects at the start of use of the recycled developing machine. Furthermore, by optimizing the initial control at the time of recycling and reuse in this embodiment, recycling with a simple cleaning process can be realized.

[0107] This embodiment has the following configuration.

[0108] The image forming apparatus 100 forms an image on a recording material 50 and includes a rotatable photosensitive member 1. The image forming apparatus 100 includes a developer carrier 42 that is rotatably mounted and contacts the surface of the photosensitive member 1 to form a development section, supplying developer 90 to the surface of the photosensitive member 1 in the development section. The image forming apparatus 100 includes a developer supply member 43 that is rotatably mounted and contacts the surface of the developer carrier 42 to supply developer to the surface of the developer carrier 42. The image forming apparatus 100 includes a developing unit that includes the developer carrier 42 and the developer supply member 43. The image forming apparatus 100 includes a calculation means 61 that serves as a developing roller travel distance calculation section that acquires information regarding the use of the developer supply member 43 and calculates the life of the developer supply member 43 using the information. The image forming apparatus 100 includes a storage unit 8 that serves as a non-volatile memory that stores first information that is information indicating that the developing unit 4 is new and second information that is information indicating that the developing unit 4 is a recycled product. The developing device includes a motor driving unit 223 that drives and rotates the developer supplying member 43, and a control unit 220 that controls the motor driving unit 223 to perform a first rotation operation and a second rotation operation different from the first rotation operation based on information stored in the storage unit 8. The control unit 220 controls the motor driving unit 223 to perform the first rotation operation when the information stored in the storage unit 8 is the first information, and controls the motor driving unit 223 to perform the second rotation operation when the information stored in the storage unit 8 is the second information.

[0109] [Example 2] The overall configuration and image forming operation of an electrophotographic image forming apparatus (hereinafter referred to as an image forming apparatus) of Example 2 will be described with reference to FIG. 15. FIG. 15 is a schematic cross-sectional view showing the general configuration of an image forming apparatus 200. In Example 2, image forming stations (hereinafter referred to as image forming units 18) of four colors, yellow, magenta, cyan, and black, are arranged side by side from left to right in the drawing. Each image forming unit is an electrophotographic image forming mechanism of similar configuration except for the color of developer (hereinafter referred to as toner) 90 contained in each developing device. In the following description, unless a particular distinction is required, the suffixes Y (yellow), M (magenta), C (cyan), and K (black) given to reference numerals to indicate that the element is provided for one of the colors will be omitted and the description will be generalized.

[0110] Each image forming unit mainly comprises a photosensitive drum 1 as a photosensitive member, a charging roller 2 as a charging means, a developing device 4, a primary transfer device 51, a cleaning member 5, etc. The exposure device 3 may be common to all the image forming units, or may be provided for each image forming unit.

[0111] The photosensitive drum 1 is a rotatable cylindrical photosensitive body, and is rotated around its axis in the direction of the arrow (counterclockwise direction) by a drive motor 223, which is a motor drive unit. In the first embodiment, the outer circumferential surface of the photosensitive drum 1 is rotated at a rotational speed of, for example, 140 mm / sec.

[0112] The surface of the photosensitive drum 1 is uniformly charged by the charging roller 2. In the first embodiment, the charging roller 2 is a conductive roller having a conductive rubber layer provided on a metal core, and is disposed in parallel with the photosensitive drum 1 in contact with it at a predetermined pressure, rotating in conjunction with the rotation of the photosensitive drum 1. Furthermore, a charging voltage can be applied to the charging roller 2 from a high-voltage power supply 224, which serves as a power supply means. In the first embodiment, the photosensitive drum 1 is charged by applying a DC voltage of, for example, -1150V to the charging roller 2, and the surface potential of the photosensitive drum 1 at this time is approximately -500V.

[0113] An exposure device 3, which is an exposure unit, scans a laser beam corresponding to an image signal over the surface of the photosensitive drum 1. As a result, an electrostatic latent image corresponding to the image signal is formed on the charged surface of the photosensitive drum 1. The image signal is input in response to a request from a user, for example, from an image reading device (not shown) connected to the image forming apparatus main body, or from a host device (not shown) such as a personal computer connected to the image forming apparatus main body so as to be able to communicate with the image forming apparatus main body.

[0114] The developing device 4 deposits toner 90, which is charged to the same polarity as the charge polarity of the photosensitive drum 1, onto portions (image portions, exposed portions) of the surface of the photosensitive drum 1 where the charge has decayed due to exposure, thereby forming a toner image, which is a developer image. In the first embodiment, the developing device 4 contains toner 90 as a non-magnetic one-component developer whose normal charge polarity (the charge polarity for developing an electrostatic latent image) is negative, for example. The developing device 4 is equipped with a rotatable developing roller 42, which is a developer carrier, a rotatable supply roller 43, which is a supply member, and a regulating blade 44, which is a regulating member. The developing roller 42 contacts the photosensitive drum 1 to form a developing section, and supplies the toner 90, which is charged to the normal charge polarity, to the photosensitive drum 1 in the developing section.

[0115] The toner image formed on the photosensitive drum 1 is electrostatically transferred to an intermediate transfer belt 53, which is a transfer receiving member, by a primary transfer device 51, which is one of the transfer members. Toner images of each color are sequentially transferred onto the intermediate transfer belt 53, superimposed on one another, to form a full-color toner image. The full-color toner image is then transferred to a recording material 50 by a secondary transfer device 52, which is a transfer member different from the primary transfer device 51. The unfixed toner image on the recording material 50 is then fixed to the recording material 50 by a fixing device 6 using pressure and heat, and the recording material 50 is discharged as a formed image outside the image forming apparatus 100. A belt cleaning device 7 is disposed downstream of the secondary transfer device 52 in the direction of movement of the intermediate transfer belt 53, and removes and collects toner 90 remaining on the intermediate transfer belt 53. Meanwhile, toner 90 remaining on the surface of the photosensitive drum 1 after the primary transfer is removed and collected by a cleaning member 5. However, the effects of the present invention are not limited to the above-described configuration. For example, an image carrier cleanerless system may be used in which the photosensitive drum 1 is not provided with a dedicated cleaning member, and the toner 90 remaining on the surface of the photosensitive drum 1 after primary transfer is collected by the developing device 4.

[0116] In the first embodiment, the photosensitive drum 1, charging roller 2, developing device 4, and cleaning member 5 are integrated as a process cartridge 10, and are configured to be detachable from the image forming apparatus main body (the portion of the image forming apparatus 100 excluding the process cartridge 10). However, the present invention is not limited to this, and the process cartridge in the present invention may be configured such that, for example, the developing device 4 is detachable from the apparatus main body alone.

[0117] <Recycled form> The recycling mode of the process cartridge 10 in the second embodiment will be described. As in the first embodiment, a used cartridge removed from the image forming apparatus 200 by a user based on a lifespan forecast or lifespan warning of the process cartridge 10 is collected at a recycling factory. If the components (image forming process members) of the collected used cartridge are recyclable, the cartridge is disassembled in a recycling process and the recyclable components are extracted. They are then regenerated as necessary and reused as components of a new cartridge.

[0118] In the recycling process after cleaning in this embodiment, the recyclable supply roller 43 is assembled as is into the developer container 4, and the developer container is filled with toner 90 anew. A new recycling bit is stored in the nonvolatile memory 8, and the life of the supply member 43 at the time of recycling is also stored in the nonvolatile memory 8. Color information of the toner at the time of recycling is also stored in the nonvolatile memory 8.

[0119] <Risks when reusing recycled developer containers> Next, we will discuss the risks involved in reusing the recycled developer container in this embodiment. This embodiment is a so-called full-color developer container, and there are cases in which the toner color used before and after recycling is different. The risks when the toner color is the same before and after recycling are the same as those described in Example 1. When the toner color is different before and after recycling, the risk at the start of use of the recycled developer container is that the toner remaining inside the supply member and the newly filled toner are different in color, resulting in color mixing. For this reason, this mixed color toner must be discharged outside the developer container to achieve the appropriate color. It is known that the degree of deterioration of the supply member affects the discharge control until the appropriate color is achieved. In other words, if the supply member is severely deteriorated, it takes a lot of voltage and time to discharge the toner.

[0120] In this embodiment, taking these factors into consideration, the voltage applied to the supply voltage and the discharge time are optimized according to the degree of deterioration of the supply member. Also, by optimizing the initial control during recycling and reuse in this embodiment, recycling can be achieved with a simple cleaning process.

[0121] <Selective control of start-up sequence> Next, a detailed description will be given of the control at the start of use of the developing container, which is a feature of the present invention. In this embodiment, the control is switched depending on the new product flag, recycle flag, and life of the supply roller, which are stored in advance in the nonvolatile memory 8. This makes it possible to perform optimal control at the start of use depending on the degree of deterioration of the supply roller.

[0122] Fig. 16 shows a detailed flowchart of the start-up process in this embodiment. First, the image forming apparatus 1 is powered on (S601). At that time, the control unit 220 checks whether or not a new product flag is present in the non-volatile memory 8 (S602). If the control unit 220 detects a new product flag, it executes the start-up control using the new product SQ shown in Fig. 11, as in the first embodiment (S603). After execution, the apparatus enters a print-ready state (S604) and waits for a job.

[0123] The purpose of the initial control in this case is the same as in the first embodiment, mainly to loosen the toner in the developing container and rotate it to improve circulation.

[0124] Next, in (S602), if the new product flag is not detected, the control unit 220 checks whether or not there is a recycle bit (S605). If the control unit 220 detects the recycle bit, it checks whether the life of the supply roller is 60% or more (S606). If the life of the supply roller is 60% or more, the control unit 220 determines whether the toner used in the recycled toner is the same as the toner information before recycling (S607). If the toner used before and after recycling is the same, the control unit 220 executes start-of-use control by recycle SQ (2A) as the second rotation operation shown in FIG. 12 (S608). Thereafter, the device enters a print-ready state (S604) and a job standby state.

[0125] The purpose of the initial control in this case is the same as in Example 1, because there is no change in the color information of the toner before and after recycling, and so control can be performed using the same concept. That is, the main purpose is to loosen the toner in the developing container, rotate the roller to improve circulation, and also to efficiently expel the toner inside the supply roller. Because the supply roller is in a state where it is not significantly deteriorated, the applied voltage required for expelling the toner can be kept low.

[0126] In step S607, if there is a change in the toner information to be used, the control unit 220 executes the start-of-use control by the recycle SQ (2B) as the second rotation operation shown in FIG. 17 (step S609).

[0127] The purpose of the initial control in this case is to loosen the toner in the developer container, rotate the roller to improve circulation, and efficiently expel the toner from inside the supply roller. The toner expelled in this state is mixed color toner. For this reason, the voltage applied when expelling toner from inside the supply roller is strengthened and the voltage application time is extended to strengthen the expulsion.

[0128] Next, in (S606), if the life of the supply roller is less than 60%, the control unit 220 checks whether the life of the supply roller is 30% or more (S610). If the life of the supply roller is less than 60% but greater than 30%, the control unit 220 determines whether the toner used in the recycled toner is the same as the toner information before recycling (S611). If the toner used before and after recycling is the same, the control unit 220 executes start-of-use control by recycle SQ (2C) as the second rotation operation shown in FIG. 13 (S612). Thereafter, the printer enters a print-ready state (S604) and a job standby state.

[0129] The purpose of the initial control in this case is the same as in Example 1, because there is no change in the color information of the toner before and after recycling, and so control can be performed using the same concept. That is, the main purpose is to loosen the toner in the developing container, rotate the roller to improve circulation, and also to efficiently expel the toner inside the supply roller. Because the supply roller is in a state where it is not significantly deteriorated, the applied voltage required for expelling the toner can be kept low.

[0130] In step S611, if there is a change in the toner information to be used, the control unit 220 executes the start-up control by the recycle SQ (2D) as the second rotation operation (S613) shown in Fig. 19. After that, the printer enters the print ready state (S604) and waits for a job.

[0131] The purpose of the initial control in this case is to loosen the toner in the developer container, rotate the roller to improve circulation, and efficiently expel the toner from inside the supply roller. The toner expelled in this state is mixed color toner. For this reason, the voltage applied when expelling the toner from inside the supply roller is increased and the voltage application time is extended to improve expulsion. However, because the supply roller is deteriorating, the time required for expulsion is longer than when the supply roller has a long remaining life.

[0132] Next, in (S610), if the life of the supply roller is less than 30%, the control unit 220 determines whether the toner used in the recycled toner is the same as the toner information before recycling (S614). If the toner used before and after recycling is the same, the control unit 220 executes start-up control by the recycle SQ (2E) as the second rotation operation shown in Figure 13 (S615). Thereafter, the printer enters the print ready state (S604) and waits for a job.

[0133] The purpose of the initial control in this case is the same as in Example 1, because there is no change in the color information of the toner before and after recycling, and so control can be performed using the same concept. That is, the main purpose is to loosen the toner in the developing container, rotate the roller to improve circulation, and also to efficiently expel the toner inside the supply roller. Because the supply roller is in a state where it is not significantly deteriorated, the applied voltage required for expelling the toner can be kept low.

[0134] If there is a change in the toner information to be used (S614), the control unit 220 executes the start-up control by the recycle SQ as the second rotation operation (S616) shown in Fig. 19. After that, the printer enters the print ready state (S604) and waits for a job.

[0135] The purpose of the initial control in this case is to loosen the toner in the developer container, rotate the roller to improve circulation, and efficiently expel the toner from inside the supply roller. The toner expelled in this state is mixed color toner. For this reason, the voltage applied when expelling toner from inside the supply roller is increased and the voltage application time is extended to improve expulsion. However, because the supply roller is deteriorating, the time required for expulsion is even longer than when the supply roller has a long remaining life. Previously, the control would end operation at tE, but this has been changed to a control that extends the expulsion time until tE is revised to improve expulsion.

[0136] <Comparative verification> In order to verify the effect of initial discharge of toner from a recycled developer container in the configuration of an embodiment of the present invention, verification was carried out using this embodiment and the following comparative example.

[0137] <Evaluation method> The effect of the control is confirmed by preparing recycled developer containers with different supply roller lifespans.

[0138] Specifically, a developing container having the following configuration was prepared. i) Recycled developer container with supply roller life of 75% ii) A recycled developer container with a supply roller life of 35% iii) Recycled developer container with supply roller life of 15% The developing containers i) to iii) above were subjected to an image output test in an environment of a temperature of 23° C. and a relative humidity of 50%.

[0139] Then, the occurrence of image defects was evaluated for each evaluation developing container. In this evaluation, the image defects were evaluated by visually judging and evaluating density unevenness in halftone image printing according to the following criteria. ○: No uneven density ×: Conspicuous unevenness in density occurs, causing practical problems Comparative Example 3 The control at the start of use is the same as that when the product is new.

[0140] Comparative Example 4 This is a control that repeats the new product control twice, assuming a conventional example, with the aim of extending the rotation time at the start of use.

[0141] The results are shown in Table 4 below.

[0142] [Table 4]

[0143] From the above verification, it was found that the conventional control did not take into account the degree of deterioration of the supply roller and did not take into account the toner color information before and after recycling, which resulted in electrostatic coagulation of the residual toner inside the supply roller and the newly replenished toner, resulting in image defects. Furthermore, because the colors of the residual toner inside the supply roller and the newly replenished toner were different, there were cases of color mixing. On the other hand, the control of the present invention selects the initial discharge control corresponding to the deterioration of the supply member, and it was confirmed that the recycled developer was stable at the start of use without suppressing the occurrence of image defects.

[0144] Furthermore, with regard to color mixing, the most severe situation occurs when the recycled toner is yellow. This is because color mixing is easily noticeable with yellow. On the other hand, when the recycled toner is black, there is little impact from color mixing, regardless of whether the toner before recycling is yellow, magenta, or cyan. When the recycled toner is magenta or cyan, the problem is less than with yellow, but more noticeable than with black. The most severe situation occurs when the toner before recycling is black and the toner after recycling is yellow. As mentioned above, color mixing is easily noticeable with yellow, and yellow is sensitive to changes in color tone caused by black.

[0145] Therefore, in a case such as iii) where the toner before recycling is black and the toner after recycling is yellow, control may be performed to increase the amount of toner 90 expelled from the supply roller 43. For example, the absolute value of the supply voltage may be increased to increase the effect of expelling toner 90, or the rotation time of the supply roller 43 may be extended. Conversely, when the recycled toner is black, control may be performed to reduce the amount of toner 90 expelled from the supply roller 43 compared to other states. When the recycled toner is magenta or cyan, control may be performed between yellow and black. The above control may also be changed depending on the toner before recycling. For example, since the black toner is the most severe, the effect of expelling toner 90 may be increased in the case of black compared to other colors. On the other hand, when the recycled toner is yellow, the effect of expelling toner 90 is less noticeable, so the effect of expelling toner 90 may be reduced compared to other colors.

[0146] As described above, in the present invention, the discharge control at the start of use is selected in response to deterioration of the supply member, so that it is possible to provide the user with stable images without image defects at the start of use of the recycled developing machine. Furthermore, by optimizing the initial control at the time of recycling and reuse in this embodiment, recycling with a simple cleaning process can be realized.

[0147] Summary of the Disclosure The present disclosure includes at least the following:

[0148] (Configuration 1) An image forming apparatus for forming an image on a recording material, a rotatable photoreceptor; a developing unit including: a developer carrier that is rotatably provided, that contacts the surface of the photosensitive member to form a developing section, and that supplies developer to the surface of the photosensitive member in the developing section; and a developer supply member that is rotatably provided, that contacts the surface of the developer carrier, and that supplies developer to the surface of the developer carrier; a calculation unit that acquires information regarding the use of the developer supply member and calculates the life of the developer supply member using the information; a storage unit that stores first information indicating that the developing unit is new and second information indicating that the developing unit is a recycled product; a drive unit that rotates the developer supply member; a control unit that controls the drive unit to perform a first rotation operation and a second rotation operation different from the first rotation operation based on information stored in the storage unit, The control unit controls the memory unit to perform the first rotation operation when the information stored in the memory unit is the first information, and controls the memory unit to perform the second rotation operation when the information stored in the memory unit is the second information.

[0149] (Configuration 2) 2. The image forming apparatus according to claim 1, wherein the control unit controls the second rotation operation so as to change the execution time of the second rotation operation based on information relating to use of the developer supply member.

[0150] (Configuration 3) a first power source for applying a supply voltage to the developer supply member; 2. The image forming apparatus according to claim 1, wherein the control unit controls the supply voltage to be applied in the second rotation operation based on information relating to use of the developer supply member.

[0151] (Configuration 4) a second power source that applies a development voltage to the developer carrier; 2. The image forming apparatus according to claim 1, wherein the control unit controls the developing voltage to be applied in the second rotation operation based on information relating to use of the developer supply member.

[0152] (Configuration 5) The image forming apparatus according to configuration 3 or 4, wherein the control unit controls the second rotation operation to change the potential difference generated between the developer carrier and the developer supply member based on information regarding the use of the developer supply member.

[0153] (Configuration 6) The image forming apparatus according to configuration 1, wherein the control unit controls the second rotation operation so that the developer carried on the surface of the developer carrier is supplied to the surface of the photosensitive member.

[0154] (Configuration 7) 2. The image forming apparatus according to claim 1, wherein the information regarding the use of the developer supplying member is the number of rotations of the developer supplying member.

[0155] (Configuration 8) a first power source for applying a supply voltage to the developer supply member; 2. The image forming apparatus according to claim 1, wherein the information regarding the use of the developer supply member is the application time during which a supply voltage is applied to the developer supply member.

[0156] (Configuration 9) The image forming apparatus according to configuration 5, wherein the control unit controls the potential difference generated between the developer carrier and the developer supply member during the first rotation operation to be changed to the potential difference generated between the developer carrier and the developer supply member during the second rotation operation.

[0157] (Configuration 10) 2. The image forming apparatus according to claim 1, wherein the developer supplying member is roller-shaped and made of a foam.

[0158] (Configuration 11) 2. The image forming apparatus according to claim 1, wherein the developer supplying member contains an ion conductive agent. [Explanation of symbols]

[0159] 1 Photosensitive drum 2 Charging roller 3 Exposure equipment 4. Developing device 8 Non-volatile memory 42 Developing roller 43 Supply roller 100 Image forming device

Claims

1. An image forming apparatus for forming an image on a recording material, a rotatable photoreceptor; a developing unit including: a developer carrier that is rotatably provided, that contacts the surface of the photosensitive member to form a developing section, and that supplies developer to the surface of the photosensitive member in the developing section; and a developer supply member that is rotatably provided, that contacts the surface of the developer carrier, and that supplies developer to the surface of the developer carrier; a calculation unit that acquires information regarding the use of the developer supply member and calculates the life of the developer supply member using the information; a storage unit that stores first information indicating that the developing unit is a new product and second information indicating that the developing unit is a recycled product; a drive unit that rotates the developer supply member; a control unit that controls the drive unit to perform a first rotation operation and a second rotation operation different from the first rotation operation based on information stored in the storage unit, The control unit controls the image forming apparatus so that the first rotation operation is performed when the information stored in the memory unit is the first information, and controls the image forming apparatus so that the second rotation operation is performed when the information stored in the memory unit is the second information.

2. 2. The image forming apparatus according to claim 1, wherein the control section controls the second rotation operation so as to change the execution time of the second rotation operation based on information relating to the use of the developer supply member.

3. a first power source for applying a supply voltage to the developer supply member; 2. The image forming apparatus according to claim 1, wherein the control section controls the supply voltage to be applied during the second rotation operation to be changed based on information relating to the use of the developer supply member.

4. a second power source that applies a development voltage to the developer carrier; 2. The image forming apparatus according to claim 1, wherein the control section controls the developing voltage to be applied in the second rotation operation based on information relating to use of the developer supply member.

5. 5. The image forming apparatus according to claim 3, wherein the control unit controls the second rotation operation to change the potential difference generated between the developer carrier and the developer supply member based on information regarding the use of the developer supply member.

6. 2. The image forming apparatus according to claim 1, wherein the control unit controls the second rotation operation so that the developer carried on the surface of the developer carrier is supplied to the surface of the photosensitive member.

7. 2. The image forming apparatus according to claim 1, wherein the information regarding the use of the developer supplying member is the number of rotations of the developer supplying member.

8. a first power source for applying a supply voltage to the developer supply member; 2. The image forming apparatus according to claim 1, wherein the information regarding the use of the developer supply member is the application time during which a supply voltage is applied to the developer supply member.

9. 6. The image forming apparatus according to claim 5, wherein the control unit controls the developer carrier and the developer supply member during the first rotation operation so as to change the potential difference between the developer carrier and the developer supply member during the second rotation operation.

10. 2. The image forming apparatus according to claim 1, wherein the developer supplying member is roller-shaped and made of a foam material.

11. 2. The image forming apparatus according to claim 1, wherein the developer supplying member contains an ion conductive agent.

Images