Image forming apparatus

Abstract

Regarding the playback unit, promptly encourage users to replace the unit before significant image quality degradation occurs. [Solution] An image forming apparatus is provided on which an image forming unit is mounted. The image forming unit includes a developing means for developing an electrostatic latent image with a developer, a storage means for storing the developer, and a storage means for storing remanufacturing information written when the image forming unit is remanufactured. The image forming apparatus includes a notification means and a control means for controlling the notification means to notify the user when the amount of developer consumed reaches a notification threshold. The control means obtains a correction coefficient for correcting a parameter used to determine whether the amount of developer consumed has reached the notification threshold, based on the remanufacturing information, corrects the parameter according to the obtained correction coefficient, and determines whether the amount of developer consumed has reached the notification threshold using the corrected parameter.

Description

Technical Field

[0001] The present invention relates to an image forming apparatus. Background Art

[0002] An image forming apparatus that operates in an electrophotographic method typically forms an electrostatic latent image on the surface of an image carrier, develops the electrostatic latent image using a developer (also referred to as toner) to form a developer image, and transfers the developer image from the image carrier to a sheet (directly or indirectly via an intermediate transfer member). In many such image forming apparatuses, components that have a shorter service life than the main body are arranged in replaceable units to facilitate maintenance work. For example, a unit generally called a process cartridge is a unit in which components involved in image formation such as a developing roller are integrated with a container containing a developer. The process cartridge is detachably mounted to the image forming apparatus during use.

[0003] In recent years, against the backdrop of growing environmental awareness, efforts have been advanced to pre-design used units so that they can be remanufactured instead of discarded for reuse in image forming apparatuses. Remanufacturers perform operations such as disassembling, cleaning, replacing deteriorated parts, refilling developer, and reassembling the collected used units. Since a remanufactured unit (hereinafter also referred to as a recycled unit) may be inferior or different in characteristics or performance from a brand-new unit, it is desirable that the image forming apparatus equipped with the recycled unit forms images under image forming conditions suitable for the recycled unit.

[0004] Patent Document 1 proposes that a remanufacturer writes information indicating the content of remanufacturing into the nonvolatile memory of a recycled unit on the premise that the content of remanufacturing differs between different remanufacturers. The image forming apparatus of Patent Document 1 reads the above information from the nonvolatile memory of the mounted recycled unit, and forms an image under image forming conditions corresponding to the content of remanufacturing. Prior Art Documents Patent Documents

[0005] [Patent Document 1] Japanese Patent Publication No. 2001-242752 [Overview of the project] [Problems that the invention aims to solve]

[0006] However, conventionally, in image forming machines equipped with a regeneration unit, when the toner level was detected to be low in the same way as when a new unit was installed, a phenomenon occurred where image quality degradation, such as white spots, occurred before the user was recommended to replace the unit. The cause of this degradation could be a decrease in the performance of the components that carry, transport, or supply the developer, a decrease in the fluidity of the toner, or the deterioration of these components over time.

[0007] In view of the above, the present invention aims to provide an improved mechanism that can prompt the user to replace the playback unit in a timely manner before the deterioration of image quality becomes significant. [Means for solving the problem]

[0008] From one perspective, an image forming apparatus is provided in which an image forming unit is detachably mounted, the image forming unit includes developing means for developing an electrostatic latent image formed on the surface of an image carrier with a developer, storage means for storing the developer, and storage means for storing remanufacturing information written when the image forming unit is remanufactured, the image forming apparatus further includes notification means and control means for controlling the notification means to notify the user when the amount of developer consumed reaches a notification threshold, the control means obtains at least one correction coefficient for correcting a parameter used to determine whether the amount of developer consumed has reached the notification threshold based on the remanufacturing information read from the storage means, corrects the parameter according to the obtained at least one correction coefficient, and determines whether the amount of developer consumed has reached the notification threshold using the corrected parameter. [Effects of the Invention]

[0009] According to the present invention, it is possible to prompt the user to replace the playback unit in a timely manner before the image quality deteriorates significantly. [Brief explanation of the drawing]

[0010] [Figure 1] A schematic cross-sectional view showing an example of the overall configuration of an image forming apparatus according to one embodiment. [Figure 2] A block diagram showing an example of the configuration of a controller and related units of an image forming apparatus according to one embodiment. [Figure 3] An explanatory diagram showing an example of the configuration of information stored in the memory device of an image forming unit. [Figure 4] A flowchart showing an example of the flow of notification control processing that can be performed in the first embodiment. [Figure 5] An explanatory diagram showing another example of the configuration of information stored in the memory device of an image forming unit. [Figure 6] A flowchart showing an example of the flow of notification control processing that may be executed in the second embodiment. [Figure 7] An explanatory diagram showing another example of the configuration of information stored in the memory device of an image forming unit. [Figure 8] A flowchart showing an example of the flow of notification control processing that may be executed in the third embodiment. [Figure 9] A schematic cross-sectional view showing an example of the overall configuration of an image forming apparatus according to the second modified example. [Figure 10] A block diagram showing an example of the configuration of the controller and related units of an image forming apparatus according to the second modified example. [Modes for carrying out the invention]

[0011] The embodiments will be described in detail below with reference to the attached drawings. Note that the following embodiments do not limit the invention as defined in the claims. While the embodiments describe multiple features, not all of these features are essential to the invention, and the features may be combined in any way. Furthermore, in the attached drawings, identical or similar configurations are given the same reference numerals, and redundant descriptions are omitted.

[0012] <1. Example of overall configuration of an image forming apparatus> First, an example of the overall configuration of an image forming apparatus 100 according to one embodiment will be described using Figure 1. The image forming apparatus 100 is an image forming apparatus in which an image forming unit is detachably mounted. In this section, an example in which the image forming apparatus 100 is a monochrome printer will be mainly described. However, the technology according to this disclosure is also applicable to color printers. Furthermore, the technology according to this disclosure is also applicable to other types of image forming apparatuses such as copiers, multifunction printers, and facsimile receivers.

[0013] Referring to Figure 1, the image forming apparatus 100 comprises an exposure unit 3, an image forming unit 10, a paper feed tray 20, a transport path 25, a transfer roller 30, a fixing unit 40, an output tray 45, and a controller 110. The image forming unit (also called a process cartridge) 10 includes a photoreceptor 1, a charging roller 2, a developing unit 4, and a cleaning unit 8. The developing unit 4 has a supply roller 5, a regulating blade 6, a developing roller 7, a toner storage section 11, and a stirrer 12. The cleaning unit 8 has a cleaning blade 9 and a waste toner storage section 13. The image forming unit 10, together with the exposure unit 3 and the transfer roller 30, functions as an image forming means for forming an image on a sheet based on input image data. The image forming apparatus 100 further includes a power supply (not shown).

[0014] The photosensitive member 1 is a cylindrical image bearing member. The photosensitive member 1 is driven by a motor (not shown) and rotates clockwise in the drawing at a predetermined process speed. The charging roller 2 is a charging unit to which a predetermined charging voltage is applied from a power source, and which charges the surface of the photosensitive member 1 to a uniform potential. The charging roller 2 is in pressure contact with the photosensitive member 1 and rotates following the rotation of the photosensitive member 1. The exposure unit 3 is an exposure unit that forms an electrostatic latent image on the surface of the photosensitive member 1 by exposing the charged surface of the photosensitive member 1 with light modulated in accordance with input image data. The exposure unit 3 may be a laser-type device that scans the surface of the photosensitive member 1 with laser light from a semiconductor laser, or may be a solid-state exposure-type device that focuses light from a plurality of light-emitting elements (LEDs) arranged along the axial direction of the photosensitive member 1 onto the surface of the photosensitive member 1. The photosensitive member 1 carries the electrostatic latent image. The toner storage portion 11 is a storage unit that stores therein toner T used for developing the electrostatic latent image. The agitator 12 has a plate-like member that rotates around a rotation axis, and agitates the toner T in the toner storage portion 11. The supply roller 5 and the developing roller 7 are developing units rotatably supported by the developing unit 4. The supply roller 5 carries the toner supplied from the toner storage portion 11 and applies the toner to the developing roller 7. The regulating blade 6 is an elastic member, and regulates and uniformizes the thickness of the layered toner applied to the surface of the developing roller 7. A predetermined developing voltage is applied to the developing roller 7 from a power source, and the electrostatic latent image on the surface of the photosensitive member 1 is developed with toner to form a toner image (developer image). The developing voltage promotes the supply of toner from the developing roller 7 to the surface of the photosensitive member 1.

[0015] When the toner is a non-magnetic one-component developer, the developing roller 7 can carry the toner mainly by intermolecular force or electrostatic force (image force). When the toner is a magnetic one-component developer or a two-component developer containing non-magnetic toner particles and a magnetic carrier, the developing roller 7 may be a cylindrical developing sleeve having a magnet inside, and can carry the toner by its magnetism.

[0016] The sheet feed tray 20 accommodates a bundle of sheets. When a print job is executed, sheets are fed one by one from the sheet feed tray 20 to the conveyance path 25. The sheets are conveyed by a plurality of conveyance rollers and reach the transfer nip between the photoreceptor 1 and the transfer roller 30. The transfer roller 30 is applied with a predetermined transfer voltage from a power supply, and transfers the toner image on the surface of the photoreceptor 1 to the sheet. The sheet to which the toner image has been transferred is further conveyed downstream along the conveyance path 25 and reaches the fixing unit 40.

[0017] The fixing unit 40 heats the toner image with heat from a heat source (for example, a ceramic heater) while nipping and conveying the sheet, and pressurizes the sheet with a pressure roller. Thereby, the toner of the toner image melts, and the toner image is fixed to the sheet. The fixing unit 40 may include a sensor (for example, a thermistor) for measuring the temperature of the fixing film in contact with the sheet, and the fixing temperature can be maintained near the target temperature based on the sensor output. The sheet that has passed through the fixing unit 40 is discharged to a discharge tray 45 by a discharge roller.

[0018] The cleaning blade 9 is a plate-shaped member fixedly disposed in the cleaning unit 8. The cleaning blade 9 removes toner remaining on the surface of the photoreceptor 1 after the toner image is transferred to the sheet. The waste toner storage portion 13 stores the toner removed by the cleaning blade 9. Note that the image forming unit 10 does not have to include the cleaning unit 8. In that case, the toner remaining on the surface of the photoreceptor 1 may be collected by a collection mechanism additionally disposed in the developing unit 4.

[0019] Note that the image forming unit that is detachably attached to the image forming apparatus 100 is not limited to the example of the image forming unit 10 described above. For example, while the image forming unit including only the developing unit 4 is detachable from the image forming apparatus 100, the photoreceptor 1, the charging roller 2, and the cleaning unit 8 may be integrated with the image forming apparatus 100.

[0020] <2. Details of the developing unit> As described above, the supply roller 5 supplies toner to the surface of the developing roller 7. The toner applied to the surface of the developing roller 7 is thinned by the regulating blade 6, which restricts its thickness. The regulating blade 6 restricts the thickness of the toner and also charges the toner, thereby charging it to the same polarity as the photoreceptor 1. The developing roller 7, carrying the thinned toner, rotates while in contact with the photoreceptor 1. The charge in the region on the surface of the photoreceptor 1 where an electrostatic latent image is formed (hereinafter referred to as the image region) is attenuated by exposure compared to the charge in other regions (hereinafter referred to as the non-image region). Therefore, the charged toner carried by the developing roller 7 adheres to the image region on the surface of the photoreceptor 1, thereby developing the electrostatic latent image. The toner remaining on the surface of the developing roller 7 can be collected in the toner storage section 11, mixed with toner T, and agitated again.

[0021] The developing roller 7 may be a single-layer roller having, for example, a metal core and a conductive elastic rubber layer around the core. The elastic rubber layer may be made of a material such as silicone rubber, urethane rubber, or hydrin rubber. Alternatively, the developing roller 7 may be a multi-layer roller having a surface layer further formed of a material such as silicone resin, urethane resin, polyamide resin, or fluororesin around the elastic rubber layer. The surface of the developing roller 7 has sufficient surface roughness to support toner. Surface roughness is expressed, for example, as arithmetic mean roughness Ra or ten-point mean roughness RzJIS, and the greater the surface roughness, the greater the amount of toner supported by the developing roller 7. The ratio of the peripheral speed of the developing roller 7 to the peripheral speed of the photoreceptor 1 is set to a predetermined value (e.g., 130%) so that the desired image density is obtained.

[0022] The supply roller 5 may be, for example, an elastic sponge roller having a metal core and a conductive foam layer around the core. For example, the conductive foam layer may be formed as a urethane foam layer containing an ionic conductive agent. The ionic conductive agent is, for example, composed of a salt of a cation and anion having a reactive functional group that reacts with an isocyanate group, and chemically bonds to the urethane foam layer via the reactive functional group. The supply roller 5 may be formed, for example, by foaming and curing a urethane composition containing an ionic conductive agent. The supply roller 5 is arranged to contact the developer roller 7 with a predetermined amount of penetration. The supply roller 5 carries and transports toner on its surface and within the foam cells inside the foam layer, and supplies toner to the developer roller 7 at the contact surface with the developer roller 7. At this time, the supply of toner T from the supply roller 5 to the developer roller 7 is stabilized by a predetermined polarity potential difference formed between the supply roller 5 and the developer roller 7. The shape and characteristics of the foam layer of the supply roller 5 (e.g., number of surface cells, cell diameter, and air permeability) and conductivity are designed to match the required toner supply performance.

[0023] The regulating blade 6 is a cantilevered, flexible elastic member that is conductive. One end of the regulating blade 6 is fixedly supported by the housing of the developing unit 4. The other end of the regulating blade 6 is a free end and contacts the outer circumferential surface of the developing roller 7 downstream in the rotational direction of the developing roller 7 from the contact surface between the supply roller 5 and the developing roller 7. In the example in Figure 1, the free end of the regulating blade 6 is oriented in a direction opposite to the rotational direction of the developing roller 7.

[0024] A DC voltage is applied from the power supply to the supply roller 5, the regulating blade 6, and the developing roller 7 in response to the start of the image forming operation. For example, the voltages applied to the supply roller 5, the regulating blade 6, and the developing roller 7 may be -450V, -450V, and -350V, respectively. When the normal charging polarity of the toner is negative, the aforementioned potential difference between the supply roller 5 and the developing roller 7 promotes the stable transfer of toner from the supply roller 5 to the developing roller 7. In addition, the potential difference between the regulating blade 6 and the developing roller 7 biases the toner towards the developing roller 7 side rather than the regulating blade 6, promoting the stable thinning of the toner on the surface of the developing roller 7 by the regulating blade 6.

[0025] The toner may be a negative-polarity, non-magnetic toner manufactured by suspension polymerization. Alternatively, the toner may be manufactured by other polymerization methods, such as grinding or emulsion polymerization. The volume-average particle size of the toner is preferably, for example, 5.0 to 8.0 μm. The volume-average particle size can be measured using the Multisizer 3 precision particle size distribution analyzer manufactured by Beckman Coulter, Inc.

[0026] Toner may contain external additives (e.g., fluidizers or cleaning aids) to improve its fluidity, chargeability, or cleaning properties. Examples of external additives may include inorganic oxide microparticles such as silica microparticles, alumina microparticles, or titanium oxide microparticles; inorganic stearic acid compound microparticles such as aluminum stearate microparticles or zinc stearate microparticles; and inorganic titanate compound microparticles such as strontium titanate or zinc titanate microparticles. One of these may be used alone, or two or more may be used in combination. These inorganic microparticles may be gloss-treated with silane coupling agents, titanium coupling agents, higher fatty acids, or silicone oils, which may improve heat resistance during storage or environmental stability. The BET specific surface area of ​​the external additive is 10 m². 2 / g or more and 450m 2It is preferable that the value is less than or equal to / g. The BET specific surface area can be derived by a low-temperature gas adsorption method using a dynamic constant-pressure method according to the BET method (preferably the BET multi-point method). For example, by using a specific surface area measuring device (product name: Gemini 2375 Ver. 5.0, manufactured by Shimadzu Corporation), nitrogen gas is adsorbed onto the sample surface, and the measurement is performed using the BET multi-point method, thereby determining the BET specific surface area (m²). 2 / g) can be derived. The total amount of these various external additives added is 0.05 parts by mass or more and 5 parts by mass or less, preferably 0.1 parts by mass or more and 3 parts by mass or less, per 100 parts by mass of toner.

[0027] <3. Remanufacturing of the image forming unit> The image forming apparatus 100 can be fitted with not only new image forming units but also remanufactured image forming units. Remanufacturing may be carried out by the manufacturer that produces new image forming units, or by another company authorized by the manufacturer. In either case, the company that performs the remanufacturing is referred to here as the remanufacturer.

[0028] The remanufacturer receives the used unit collected from the user by the recycling company, disassembles it into several parts, and cleans each part. The remanufacturer also inspects each part and replaces any faulty, deteriorated, or nearing the end of their lifespan with other parts. In this case, the new parts are not necessarily identical to the original parts. The remanufacturer fills the cleaned toner container or the new toner container with toner. Finally, the remanufacturer reassembles the multiple parts to regenerate the image forming unit.

[0029] Therefore, the image forming apparatus 100 may be equipped with one of several types of image forming units having different characteristics or performance. The memory device M disposed in each image forming unit is a storage means for storing remanufacturing information that is written when the image forming unit is remanufactured. The memory device M may be, for example, an integrated circuit (IC) chip equipped with semiconductor memory. In the example in Figure 1, the memory device M is disposed in the housing of the cleaning unit 8. However, the memory device M may be disposed in other locations in the image forming unit 10. The information written to the memory device M will be explained further later.

[0030] <4. Example of Controller Configuration> Figure 2 is a block diagram showing an example of the configuration of the controller 110 and related units of the image forming apparatus 100. Referring to Figure 2, the controller 110 includes a communication interface (I / F) 111, a connection I / F 112, an operation I / F 113, a printer I / F 114, a CPU 115, RAM 116, and ROM 117.

[0031] The communication interface 111 is an interface for the image forming apparatus 100 to communicate with an external device (for example, a personal computer (PC) or a host computer). The connection interface 112 is an interface for connecting the controller 110 to the memory device M of the image forming unit 10. When the image forming unit 10 is mounted on the image forming apparatus 100, the connection interface 112 communicates with the memory device M to detect the mounting of the image forming unit 10. The operation interface 113 is an interface for connecting the controller 110 to an operation unit 70, which is not shown in Figure 1. The operation unit 70 provides a user interface to the user of the image forming apparatus 100. The operation unit 70 may include, for example, input devices such as touch sensors, buttons and switches, as well as output devices such as a display and a speaker. The printer interface 114 is an interface for connecting the controller 110 to the various components that constitute the image forming means described above.

[0032] The central processing unit (CPU) 115 is a control means that controls the overall functions of the image forming apparatus 100. The CPU 115 can read information from the readable storage area of ​​the memory device M of the image forming unit 10 via the connection I / F 112, and can write information to the writable storage area of ​​the memory device M. The random access memory (RAM) 116 is a volatile memory that provides the CPU 115 with a temporary storage area for calculations. The read-only memory (ROM) 117 is a non-volatile memory that pre-stores computer programs and related data. In this embodiment, the CPU 115 functions as a print control unit 121 and a notification control unit 122 by executing a computer program loaded from the ROM 117 into the RAM 116.

[0033] The print control unit 121 controls the execution of print jobs. Print jobs are received from external devices via the communication interface 111 or via the operation unit 70. The print control unit 121 controls the image forming means to form an image on the sheet based on the input image data of the received print job.

[0034] When a print job is executed, the toner stored in the toner storage unit 11 of the image forming unit 10 is consumed. The memory device M stores status information indicating the cumulative amount of toner consumed in the toner storage unit 11. The notification control unit 122 controls the notification means of the image forming apparatus 100 to notify the user when the cumulative amount of toner consumed reaches a notification threshold. For example, the display and speaker of the operation unit 70 may function as notification means that provide visual and auditory notifications, respectively. Alternatively, the communication I / F 111 may function as a notification means that transmits a notification message to an external device.

[0035] More specifically, the notification control unit 122 estimates the toner consumption each time a print job is executed and updates the status information in the memory device M. The notification control unit 122 also determines whether the cumulative toner consumption has reached a notification threshold. If the notification control unit 122 determines that the cumulative toner consumption has reached a notification threshold, it causes the notification means to issue a notification prompting the user to replace the image forming unit 10. If the notification control unit 122 determines that the cumulative toner consumption has not reached a notification threshold, it may control the notification means to notify the user of the latest toner level.

[0036] <5. Estimation of toner consumption> In this embodiment, the notification control unit 122 estimates the toner consumption for each print job based on a so-called video count value (or pixel count value). Specifically, for each page to be printed, the notification control unit 122 counts the number of exposed pixels that constitute an image area based on the input image data. The input image data here is rasterized and binarized data, and indicates whether exposure is on or off for each pixel position. Therefore, the number of pixels indicating exposure on in the input image data corresponds to the video count value of the image area. Since such a video count value correlates with the toner consumption required to print each page, in this embodiment, the video count value is treated as an indicator of toner consumption. In other embodiments, other parameters obtained by performing some unit conversion on the video count value may be treated as indicators of toner consumption.

[0037] The notification control unit 122 tracks the cumulative toner consumption by accumulating an estimated toner consumption value to a value that is initialized to zero when the image forming unit 10 is manufactured or remanufactured. To improve the accuracy of the toner consumption estimation, the notification control unit 122 may further consider a phenomenon called "fogging" in non-image areas. Fogging refers to the phenomenon in which a small amount of toner adheres to non-image areas that are not exposed in the electrostatic latent image during development, causing toner consumption. It is known that as the components involved in the development of the electrostatic latent image deteriorate over time, the proportion of toner consumed due to fogging increases. To estimate the toner consumption due to fogging, the notification control unit 122 counts the number of unexposed pixels that constitute the non-image area based on the input image data for each page to be printed, and calculates the video count value of the non-image area. Furthermore, the notification control unit 122 calculates the toner consumption of the non-image area by multiplying the video count value of the non-image area by a predetermined fogging coefficient. The fogging coefficient represents the ratio of the amount of toner consumed per unexposed pixel in the non-image area to the amount of toner consumed per exposed pixel in the image area. Typically, the value of the fogging coefficient is significantly less than 1. The notification control unit 122 may estimate the total toner consumption by adding the toner consumption of the non-image area (second consumption component), calculated in this way, to the toner consumption of the image area (first consumption component) as described above.

[0038] In this embodiment, since the video count value is treated as an indicator of toner consumption, the notification threshold that triggers notification to the user is also set in the form of the video count value. If toner consumption is expressed as a percentage of the maximum value (for example, the amount of toner filled during manufacturing or remanufacturing), the notification threshold may also be set in the form of a percentage. In addition, the arrival of the notification threshold for toner consumption may be determined indirectly using the remaining toner amount, which decreases with each print job, rather than directly using the toner consumption amount, which increases with each print job. In that case, the remaining toner amount is compared with a remaining amount threshold corresponding to the notification threshold.

[0039] <6. Examples of information stored in a memory device> Figure 3 is an explanatory diagram showing an example of the configuration of information stored in the memory device M of the image forming unit 10. Referring to Figure 3, the memory device M has an original information area M1, a remanufacturing information area M2, and a status information area M3.

[0040] The original information area M1 is a memory area where information about a new image forming unit 10 (hereinafter referred to as original information) is written. The original information area M1 is read-only (RO). That is, once the original information has been written, reading information from the original information area M1 is permitted, but writing information to the original information area M1 is prohibited.

[0041] The remanufacturing information area M2 is a memory area where information about the remanufactured image forming unit 10 (hereinafter referred to as remanufacturing information) is written. The remanufacturing information area M2 is read-write (RW). That is, both reading information from and writing information to the remanufacturing information area M2 are permitted.

[0042] The status information area M3 is a storage area where status information regarding toner usage within the image forming unit 10 is written, regardless of whether or not remanufacturing has been performed. The status information area M3 is read-write (RW).

[0043] More specifically, the original information includes the information items "printable pages", "notification threshold", and "fogging coefficient". The "printable pages" is a value calculated based on the capacity of the toner storage section 11 of the image forming unit 10 or the amount of toner filled, for example, according to the ISO / IEC 19798 standard. The "notification threshold" is a threshold for triggering the notification mentioned above regarding the decrease in toner level. As mentioned above, in this embodiment, the "notification threshold" is expressed in the form of a video count value and can be compared with the cumulative video count value described later. The "fogging coefficient" is a coefficient used to estimate the amount of toner consumed in non-image areas due to "fogging".

[0044] The remanufacturing information includes two information items: "remanufacturing flag" and "whiteout correction coefficient." The "remanufacturing flag" is a flag indicating whether the image forming unit 10 is new or remanufactured. The value of the "remanufacturing flag" is, for example, set to zero or false when a new image forming unit 10 is manufactured, and updated to 1 or true when it is remanufactured. The "whiteout correction coefficient" is an example of a correction coefficient for correcting parameters used to determine the notification timing. The use of the "whiteout correction coefficient" will be explained in detail later.

[0045] The status information includes the information items "Cumulative Video Count" and "Toner Remaining." The "Cumulative Video Count" indicates the total amount of toner consumed after the image forming unit 10 was installed in the image forming apparatus 100, in the form of a video count value. The "Toner Remaining" is the remaining amount obtained by subtracting the amount consumed from the total amount of toner, and is shown as a percentage of the total amount. Here, the value of the "Notification Threshold" is assumed to substantially represent the total amount of toner that can be consumed. The values ​​of "Cumulative Video Count" and "Toner Remaining" are updated each time a print job is executed. In addition, when the image forming unit 10 is remanufactured, the value of "Cumulative Video Count" may be reset to zero and the value of "Toner Remaining" may be reset to 100[%].

[0046] Note that the configuration of the information stored in memory device M is not limited to the example shown in Figure 3. For example, in order to enable setting a notification threshold specific to the remanufacturing unit, the remanufacturing information may include an information item called "notification threshold".

[0047] The manufacturer of the image forming unit 10 ships the image forming unit 10 with initial values ​​of original information, remanufacturing information, and status information written to the memory device M. A remanufacturer authorized by the manufacturer has means to write the remanufacturing information to the memory device M and writes the remanufacturing information to the memory device M that reflects the configuration of the remanufactured image forming unit 10. The memory device M may be capable of storing additional information (e.g., a digital signature) to guarantee that the remanufacturing information was written by a legitimate remanufacturer. Some authentication may be performed when the remanufacturing information is written by an authentication server provided by the manufacturer. Alternatively, the manufacturer may write the remanufacturing information to the memory device M at the request of the remanufacturer.

[0048] <7. Correction of parameters for determining notification timing> As described above, the performance or characteristics of the components of a remanufactured image forming unit (recycled unit) may differ from those of a new image forming unit. For example, if used supply rollers and developer rollers are cleaned and reused, the toner supply performance will decrease compared to new ones. As a result, even if the toner level is the same, white spots that would not occur in a new unit may occur earlier in a recycled unit. White spots can also occur when low-fluidity toner is used. Conversely, if the toner supply performance of a recycled unit improves compared to a new unit due to the replacement of some component, and the same threshold is used to determine the notification timing, it may result in the user being notified to replace the unit unnecessarily early. Therefore, in the embodiment described below, when the image forming unit is remanufactured, a correction coefficient for correcting the parameters used to determine the notification timing is written to the memory device M of the recycled unit.

[0049] <7-1. First Example> Through the several embodiments described below, the parameters used to determine the notification timing include toner consumption estimated based on the video count value, and a notification threshold compared to the toner consumption. In the first embodiment, the remanufacturing information includes correction coefficient information (the "whiteout correction coefficient" in Figure 3) that indicates a whiteout correction coefficient for correcting the toner consumption among these parameters.

[0050] The notification control unit 122 reads remanufacturing information from the memory device M installed in the image forming apparatus 100 and obtains a whiteout correction coefficient. When a print job is executed, the notification control unit 122 corrects the toner consumption estimated based on the video count value according to the whiteout correction coefficient. Then, if the notification control unit 122 determines that the corrected toner consumption has reached a notification threshold, it causes the notification means to notify the user to replace the unit.

[0051] For a new image forming unit 10, the initial value of the whiteout correction coefficient of the memory device M is 1.0, which means that toner consumption is not corrected. If the toner supply performance deteriorates due to remanufacturing, the whiteout correction coefficient is set to a value greater than 1.0. In this case, for the same video count value, the toner consumption is corrected to a larger value, and the notification threshold is reached faster. If the toner supply performance improves due to remanufacturing, the whiteout correction coefficient is set to a value less than 1.0. In this case, for the same video count value, the toner consumption is corrected to a smaller value, and the notification threshold is reached slower.

[0052] Figure 3 shows an example in which the remanufacturing information directly includes correction coefficient information indicating a whiteout correction coefficient, but the technology relating to this disclosure is not limited to such an example. For example, the remanufacturing information may include configuration information that identifies the components constituting the image forming unit 10 after remanufacturing. The configuration information here may be information indicating one or more types, performance, or characteristics of components such as a supply roller, a developing roller, and toner. The performance or characteristics of the components may include, for example, one or more of the surface roughness of the developing roller, the conductivity of the developing roller, the air permeability of the foam layer of the supply roller, the conductivity of the supply roller, the fluidity of the toner, and the chargeability of the toner. In this case, the notification control unit 122 can determine the value of the correction coefficient based on the configuration information contained in the remanufacturing information read from the memory device M (for example, according to a predefined correspondence between the configuration information and the correction coefficient, or according to a calculation formula).

[0053] Figure 4 is a flowchart showing an example of the flow of the notification control process that can be executed by the notification control unit 122 in this embodiment.

[0054] The notification control process shown in Figure 4 is initiated in S10 when the image forming apparatus 100 accepts a print job. Prior to accepting the print job, the notification control unit 122 is assumed to have acquired information such as the notification threshold, fringe coefficient, whiteout correction coefficient, cumulative video count, and toner level from the memory device M of the image forming unit 10 installed in the image forming apparatus 100. The processing steps following S10 may be repeated for each page of the print job.

[0055] In S12, the notification control unit 122 acquires input image data for one page to be printed. The input image data indicates whether exposure is on or off for each pixel position. Then, in S14, the notification control unit 122 counts the number of exposed pixels indicated by the input image data and derives the video count value Vn1 for the image area. The video count value Vn1 is an indicator (also called the first consumption component) of the amount of toner estimated to be consumed in the image area.

[0056] Next, in S16, the notification control unit 122 counts the number of unexposed pixels indicated by the input image data to derive a video count value Vn2 for the non-image area, and multiplies the video count value Vn2 by the overlap coefficient K. The product of the video count value Vn2 for the non-image area and the overlap coefficient K is an indicator of the amount of toner estimated to be consumed in the non-image area (also called the second consumption component).

[0057] Next, in S18, the notification control unit 122 calculates the total toner consumption Vn, which is equal to the sum of the first consumption component and the second consumption component, according to the following formula. Vn = Vn1 + K·Vn2

[0058] Next, in S20, the notification control unit 122 corrects the total toner consumption Vn by multiplying it by the whiteout correction coefficient C, according to the following formula. Vn ← C·Vn If the "remanufacturing flag" included in the remanufacturing information indicates that the image forming unit 10 is new, S20 may be skipped.

[0059] Next, in S22, the notification control unit 122 updates the cumulative video count value Vt by adding the total toner consumption Vn corrected in S20, according to the following formula. Vt ← Vt+Vn The notification control unit 122 writes the updated cumulative video count value Vt to the status information area M3 of the memory device M.

[0060] Next, in S24, the notification control unit 122 calculates the remaining toner amount Tj, expressed as a percentage, using the notification threshold Vth and the updated cumulative video count value Vt, according to the following formula. Tj = (1 - Vt / Vth) × 100 Initially, when the image forming unit 10 is installed in the image forming apparatus 100, the cumulative video count value Vt is equal to zero, and the toner level Tj shows 100%. When the updated cumulative video count value Vt reaches the notification threshold Vth, the toner level Tj shows 0% or a negative value. The notification control unit 122 writes the value of the toner level Tj to the status information area M3 of the memory device M.

[0061] Next, in S26, the notification control unit 122 determines whether the updated cumulative video count value Vt has reached the notification threshold Vth. If the updated cumulative video count value Vt is greater than or equal to the notification threshold Vth (Vt≧Vth, Tj≦0), the notification control unit 122 determines that it should notify the user about the decrease in toner level. In this case, the process proceeds to S28. On the other hand, if the updated cumulative video count value Vt falls below the notification threshold Vth (Vt<Vth、Tj> 0) It is determined that it is not necessary to notify the user about the low toner level, and the process proceeds to S32.

[0062] In S28, the notification control unit 122 notifies the user of the low toner level. For example, a notification screen is displayed on the display of the operation unit 70. Next, in S30, the notification control unit 122 receives user input indicating whether or not the running print job should be stopped. If the user is instructed to continue the print job, the process proceeds to S32. On the other hand, if the user is instructed to stop the print job, the notification control process shown in Figure 4 ends.

[0063] In S32, the notification control process branches depending on whether or not a subsequent page exists. If a subsequent page exists, the process returns to S12, and steps S12 to S30 described above are repeated for the next page. If the print job is instructed to continue in S30, even if the toner consumption for subsequent pages exceeds the notification threshold, the user may not be asked whether to continue or stop the job, and the print job may be automatically selected to continue. If no subsequent pages exist, the notification control process shown in Figure 4 terminates.

[0064] While this example describes a method for determining whether toner consumption should be estimated for each printed page and notified to the user, the technology relating to this disclosure is not limited to such an example. For example, the notification control unit 122 may estimate toner consumption (totaled across one or more pages) for each print job and determine whether to notify the user.

[0065] In the first embodiment described above, for a replaceable image forming unit, a correction coefficient for correcting the estimated toner consumption is obtained based on remanufacturing information written to the memory device of the image forming unit 10. The remanufacturing information is determined according to the performance or characteristics of the components that make up the image forming unit after remanufacturing. Therefore, for a remanufactured unit composed of components with relatively low toner supply performance, the user can be notified in a timely manner that the remanufactured unit should be replaced when the toner is consumed to the point where white spots occur. Furthermore, for a remanufactured unit composed of components with relatively high toner supply performance, it is possible to avoid a situation where the user is prompted to replace the remanufactured unit too early.

[0066] In Figure 4, an example is shown where one notification threshold is compared with the toner consumption. However, the notification control unit 122 may compare the toner consumption with multiple different notification thresholds. For example, the first notification threshold may correspond to a toner level of 10%, and the second notification threshold may correspond to a toner level of 0%. In this case, when the toner consumption reaches the first notification threshold, the notification control unit 122 will notify the user that it is soon time to replace the image forming unit. Furthermore, when the toner consumption reaches the second notification threshold, the notification control unit 122 will warn the user that the image forming unit should be replaced immediately. Through this multi-stage notification system, the user can prepare in advance for replacing the image forming unit before actual image quality degradation, such as white spots, occurs.

[0067] Furthermore, while Figure 4 illustrates an example where the user is notified when the toner consumption reaches a notification threshold, the user may be provided with remaining toner information (for example, displayed on the screen) even before the toner consumption reaches the notification threshold. This would allow the user to always know how much toner remains in the image forming unit, potentially improving usability.

[0068] <7-2. Second Example> In the second embodiment as well, the remanufacturing information includes correction coefficient information that indicates a correction coefficient for correcting toner consumption among the parameters used to determine the notification timing. However, in the second embodiment, a correction coefficient for correcting the first consumption component based on the video count value of the image area and a correction coefficient for correcting the second consumption component based on the video count value of the non-image area are given separately. In the following description, the former will be referred to as the whiteout correction coefficient and the latter as the blackout correction coefficient.

[0069] Figure 5 is an explanatory diagram showing another example of the configuration of information stored in the memory device M of the image forming unit 10. In the example of Figure 5, the remanufacturing information contained in the remanufacturing information area M2 differs from that in the example of Figure 3. In addition to the "remanufacturing flag" and "whiteout correction coefficient" described above, the remanufacturing information includes an information item called "fade correction coefficient". In this embodiment, the "whiteout correction coefficient" indicates the value of the first correction coefficient for correcting the first consumption component. The "fade correction coefficient" indicates the value of the second correction coefficient for correcting the second consumption component.

[0070] The notification control unit 122 reads remanufacturing information from the memory device M installed in the image forming apparatus 100 and obtains a whiteout correction coefficient and a fringe correction coefficient. When a print job is executed, the notification control unit 122 estimates a first consumption component based on the video count value of the image area and a second consumption component based on the video count value of the non-image area in the same manner as in the first embodiment. In this embodiment, the notification control unit 122 corrects these first and second consumption components separately by multiplying them by the whiteout correction coefficient and the fringe correction coefficient, respectively. The toner consumption may be the sum of the first and second consumption components thus corrected. When the notification control unit 122 determines that the toner consumption has reached a notification threshold, it causes the notification means to notify the user to replace the unit.

[0071] For a new image forming unit 10, the initial values ​​of the whiteout correction coefficient and the fringe correction coefficient of the memory device M are 1.0, which means that the first and second consumption components are not corrected. For a remanufactured image forming unit 10, the whiteout correction coefficient and the fringe correction coefficient may show values ​​different from the initial values.

[0072] For example, suppose an image forming unit is used to print a large number of images with a low average print density. If we compare the condition of this image forming unit to that of another image forming unit used to print a small number of images with a high average print density, even if the cumulative toner consumption is the same, the former tends to experience more toner degradation over a longer period of use. Toner degradation causes a decrease in toner fluidity, and this decrease in fluidity can cause white spots. In particular, if components with low toner supply performance are used, the effect of decreased fluidity will be more pronounced in the print results.

[0073] Therefore, in this embodiment, the second correction coefficient applied to the second consumption component, i.e., the fogging correction coefficient, is set to a larger value than the first correction coefficient applied to the first consumption component, i.e., the whiteout correction coefficient. This makes it possible to reflect the progression of toner degradation caused by printing a large number of images with low print density in the estimated toner consumption, and to notify the user in a timely manner even when toner degradation progresses more significantly.

[0074] In addition, similar to the first embodiment, the remanufacturing information may include configuration information that identifies the components constituting the remanufactured image forming unit 10, instead of directly including correction coefficient information indicating the whiteout correction coefficient and the fogging correction coefficient. In this case, the notification control unit 122 may determine the values ​​of the whiteout correction coefficient and the fogging correction coefficient based on the configuration information included in the remanufacturing information read from the memory device M (for example, according to a predefined correspondence between the configuration information and the correction coefficient, or according to a calculation formula).

[0075] Figure 6 is a flowchart showing an example of the flow of the notification control process that can be executed by the notification control unit 122 in this embodiment.

[0076] The notification control process shown in Figure 6 is initiated in S10 when the image forming apparatus 100 accepts a print job. Prior to accepting the print job, the notification control unit 122 is assumed to have acquired information such as the notification threshold, fringe coefficient, whiteout correction coefficient, cumulative video count, and toner level from the memory device M of the image forming unit 10. The processing steps following S10 may be repeated for each page of the print job.

[0077] In S12, the notification control unit 122 acquires input image data for one page to be printed. Then, in S13, the notification control unit 122 counts the number of exposed pixels and unexposed pixels indicated by the input image data to derive the video count value Vn1 for the image area and the video count value Vn2 for the non-image area.

[0078] Next, in S15, the notification control unit 122 corrects the video count value Vn1 representing the first consumption component by multiplying it by the whiteout correction coefficient C1, according to the following equation. Vn1' = C1·Vn1

[0079] Next, in S17, the notification control unit 122 corrects the second consumption component, which corresponds to the product of the video count value Vn2 of the non-image area and the overlap coefficient K, by multiplying it by the overlap correction coefficient C2, according to the following equation. Vn2' = C2·K·Vn2

[0080] Next, in S19, the notification control unit 122 calculates the total toner consumption Vn, which is equal to the sum of the corrected first consumption component Vn1' and the corrected second consumption component Vn2', according to the following formula. Vn = Vn1´+Vn2´ = C1·Vn1+C2·K·Vn2

[0081] Next, in S22, the notification control unit 122 updates the cumulative video count value Vt by adding the total toner consumption Vn calculated in S19. The subsequent steps S24 to S32 may be the same as the processing steps described with reference to Figure 4 in relation to the first embodiment, so the description of those processing steps is omitted here.

[0082] In the second embodiment described above, for a replaceable image forming unit, first and second correction coefficients for correcting the estimated toner consumption are obtained based on remanufacturing information written to the memory device of the image forming unit 10. The first correction coefficient is a coefficient for correcting the first consumption component estimated based on the number of exposed pixels, and the second correction coefficient is a coefficient for correcting the second consumption component estimated based on the number of unexposed pixels. The remanufacturing information is determined according to the performance or characteristics of the components constituting the image forming unit after remanufacturing. In this way, by making it possible to set an independent correction coefficient for the second consumption component, which represents the toner consumption caused by "fogging," the difference in the degree of toner degradation caused by differences in print density can be reflected in the parameters used to determine the notification timing. This makes it possible to provide notifications to prompt the user to replace the unit in a more timely manner.

[0083] <7-3. Third Example> In the third embodiment, the remanufacturing information includes correction coefficient information that indicates a threshold correction coefficient (third correction coefficient) for correcting the notification threshold among the parameters used to determine the notification timing.

[0084] Figure 7 is an explanatory diagram showing another example of the configuration of information stored in the memory device M of the image forming unit 10. In the example of Figure 7, the remanufacturing information contained in the remanufacturing information area M2 differs from the examples in Figures 3 and 5. In addition to the "remanufacturing flag" described above, the remanufacturing information includes an information item called a "threshold correction coefficient". In this embodiment, the "threshold correction coefficient" indicates the value of a coefficient used to correct the notification threshold, which is compared with the toner consumption amount for determining the notification timing.

[0085] The notification control unit 122 reads remanufacturing information from the memory device M installed in the image forming apparatus 100 to obtain a threshold correction coefficient, and corrects the notification threshold using the obtained threshold correction coefficient. When a print job is executed, the notification control unit 122 estimates the toner consumption by summing the first consumption component based on the video count value of the image area and the second consumption component based on the video count value of the non-image area, in the same manner as in the first embodiment. The notification control unit 122 then compares the estimated toner consumption with the corrected notification threshold, and if it determines that the toner consumption has reached the notification threshold, it causes the notification means to issue a notification prompting the user to replace the unit.

[0086] The threshold correction coefficient may be, for example, a value used to divide the notification threshold. For a new image forming unit 10, the initial value of the threshold correction coefficient of the memory device M is 1.0, which means that the notification threshold is not corrected. If toner supply performance decreases due to remanufacturing, the threshold correction coefficient is set to a value greater than 1.0. In this case, as a result of the division, the notification threshold decreases, and the toner consumption reaches the notification threshold faster. If toner supply performance improves due to remanufacturing, the threshold correction coefficient is set to a value less than 1.0. In this case, as a result of the division, the notification threshold increases, and the toner consumption reaches the notification threshold slower. Alternatively, the threshold correction coefficient may be a coefficient multiplied by the notification threshold, or an offset added to or subtracted from the notification threshold.

[0087] Similar to the first and second embodiments, the remanufacturing information may include configuration information that identifies the components constituting the remanufactured image forming unit 10, instead of directly including correction coefficient information that indicates the threshold correction coefficient. In this case, the notification control unit 122 may determine the value of the threshold correction coefficient based on the configuration information included in the remanufacturing information read from the memory device M (for example, according to a predefined correspondence between configuration information and the correction coefficient, or according to a calculation formula).

[0088] Figure 8 is a flowchart showing an example of the flow of the notification control process that can be executed by the notification control unit 122 in this embodiment.

[0089] The notification control process shown in Figure 8 is initiated in S10 when the image forming apparatus 100 accepts a print job. Prior to accepting the print job, the notification control unit 122 is assumed to have acquired information such as the notification threshold, fogging coefficient, threshold correction coefficient, cumulative video count, and toner level from the memory device M of the image forming unit 10. The processing steps following S10 may be repeated for each page of the print job.

[0090] In S12, the notification control unit 122 acquires input image data for one page to be printed. Then, in S14, the notification control unit 122 counts the number of exposed pixels indicated by the input image data and derives the video count value (first consumption component) Vn1 of the image area.

[0091] Next, in S16, the notification control unit 122 counts the number of unexposed pixels indicated by the input image data to derive a video count value Vn2 for the non-image area, and calculates the product of the video count value and the overlap coefficient (second consumption component) K·Vn2.

[0092] Next, in S18, the notification control unit 122 calculates the total toner consumption Vn (=Vn1+K·Vn2), which is equal to the sum of the first consumption component and the second consumption component.

[0093] Next, in S21, the notification control unit 122 corrects the notification threshold Vth by dividing it by the threshold correction coefficient C according to the following equation. Vth ← Vth / C If the "remanufacturing flag" included in the remanufacturing information indicates that the image forming unit 10 is new, S21 may be skipped.

[0094] Next, in S23, the notification control unit 122 updates the cumulative video count value Vt by adding the total toner consumption Vn calculated in S18, according to the following formula. Vt ← Vt+Vn The notification control unit 122 writes the updated cumulative video count value Vt to the status information area M3 of the memory device M.

[0095] Next, in S25, the notification control unit 122 calculates the remaining toner amount Tj, expressed as a percentage, using the corrected notification threshold Vth and the updated cumulative video count value Vt, according to the following formula. Tj = (1 - Vt / Vth) × 100 Initially, when the image forming unit 10 is installed in the image forming apparatus 100, the cumulative video count value Vt is equal to zero, and the toner level Tj shows 100%. When the updated cumulative video count value Vt reaches the corrected notification threshold Vth, the toner level Tj shows 0% or a negative value. The notification control unit 122 writes the value of the toner level Tj to the status information area M3 of the memory device M.

[0096] Next, in S27, the notification control unit 122 determines whether the updated cumulative video count value Vt has reached the corrected notification threshold Vth. If the updated cumulative video count value Vt is greater than or equal to the corrected notification threshold Vth (Vt≧Vth, Tj≦0), the notification control unit 122 determines that it should notify the user about the decrease in toner level. In this case, the process proceeds to S28. On the other hand, if the updated cumulative video count value Vt is less than the corrected notification threshold Vth (Vt<Vth、Tj> 0) It is determined that it is not necessary to notify the user about the low toner level, and the process proceeds to S32.

[0097] Since steps S28 to S32 are the same as the processing steps described with reference to Figure 4 in relation to the first embodiment, the explanation of those processing steps will be omitted here.

[0098] In the third embodiment described above, for replaceable image forming units, a correction coefficient for correcting the notification threshold compared with the toner consumption is obtained based on remanufacturing information written to the memory device of the image forming unit 10. The remanufacturing information is determined according to the performance or characteristics of the components that make up the image forming unit after remanufacturing. Therefore, for remanufactured units composed of components with relatively low toner supply performance, the user can be notified in a timely manner that the remanufactured unit should be replaced when the toner is consumed to the point where white spots occur. Furthermore, for remanufactured units composed of components with relatively high toner supply performance, it is possible to avoid a situation where the user is prompted to replace the remanufactured unit too early.

[0099] <8. Verification of effectiveness> To verify the effects of the above-described embodiments, verification experiments were conducted to evaluate whether the image forming apparatus according to the comparative example and the first to third embodiments provides timely notification to prompt replacement of the regeneration unit.

[0100] <8-1. Six possible configurations for image forming units> For verification experiments, we prepared image forming units with six configurations T1 to T6, as shown in Table 1. Configuration T1 corresponds to the configuration of a new image forming unit, while configurations T2 to T6 correspond to the configurations of remanufactured image forming units.

[0101] [Table 1]

[0102] The characteristics of the toners used in configurations T1 to T6 shown in Table 1 are as follows. Note that toners with higher fluidity are more advantageous in terms of toner supply performance. ·toner - Genuine product: Toner manufactured by the authorized manufacturer. -Non-genuine product A: Toner manufactured by another manufacturer. Lower fluidity compared to genuine product. -Non-genuine product B: Toner manufactured by another manufacturer. It has higher fluidity compared to genuine products.

[0103] The performance of the developing roller and supply roller used in configurations T1 to T6 shown in Table 1 is as follows: • Developing roller -Genuine and brand new: Unused rollers manufactured by the official manufacturer. - Genuine and refurbished: Used rollers manufactured by the official manufacturer. Due to repeated friction and filming, the surface roughness and conductivity are slightly deteriorated compared to genuine and new parts. - Non-genuine and new: Unused rollers manufactured by other manufacturers. Compared to genuine parts, they have less surface roughness and slightly lower toner supply performance. - Non-genuine and refurbished: Used rollers manufactured by other manufacturers. Due to repeated friction and filming, they are non-genuine and have slightly deteriorated surface roughness and conductivity compared to new products. • Supply roller -Genuine and brand new: Unused rollers manufactured by the official manufacturer. - Genuine and refurbished: Used rollers manufactured by the official manufacturer. Due to repeated electrical contact, the conductivity is slightly degraded compared to genuine and new parts. - Non-genuine and new: Unused rollers manufactured by other manufacturers. Compared to genuine parts, they have lower conductivity and slightly lower toner supply performance. - Non-genuine and refurbished: Used rollers manufactured by other manufacturers. Due to repeated electrical contact, they are non-genuine and have slightly degraded conductivity compared to new parts.

[0104] As shown in Table 1, the image forming unit of configuration T1 contains genuine toner and includes a genuine and new developer roller and a genuine and new supply roller. The image forming unit of configuration T2 contains genuine toner and includes a genuine and remanufactured developer roller and a genuine and remanufactured supply roller. The image forming unit of configuration T3 contains non-genuine toner A and includes a non-genuine and new developer roller and a non-genuine and new supply roller. The image forming unit of configuration T4 contains non-genuine toner A and includes a genuine and remanufactured developer roller and a genuine and remanufactured supply roller. The image forming unit of configuration T5 contains non-genuine toner A and includes a non-genuine and remanufactured developer roller and a non-genuine and remanufactured supply roller. The image forming unit of configuration T6 contains non-genuine toner B and includes a genuine and remanufactured developer roller and a genuine and remanufactured supply roller.

[0105] <8-2. Evaluation Method> In the following two operating modes M1 and M2, the image forming units having the above-described configurations T1 to T6 were mounted on the image forming apparatus, and the image forming operation was repeated until the toner consumption reached the notification threshold (i.e., until the remaining toner went from 100% to 0%). • Operation mode M1: Continuously prints A4-sized images with 30% print coverage. • Operation mode M2: Intermittently prints A4-sized images with 1% print coverage. Intermittent printing in operating mode M2 ​​refers to a process where, after printing a predetermined number of sheets, the image formation operation is stopped for a certain period of time, and then restarted to perform subsequent printing. In continuous printing in operating mode M1, the image formation operation is not stopped from start to finish. The experimental environment temperature was 23°C and the relative humidity was 50%. When the toner consumption reached the notification threshold and the toner level became 0%, an A4-sized all-black image was printed on another sheet, and the degree of white gaps was visually evaluated.

[0106] <8-3. Evaluation Results> The evaluation results of the degree of white spots are shown in Tables 2 to 4 below using the following symbols. ◎: No white spots occurred. ○: Minor white spots occur, but do not pose a practical problem. ×: There is a noticeable amount of white space, which poses a practical problem.

[0107] (1) Comparative Example The configuration of the image forming apparatus in the comparative example is the same as that of the image forming apparatus 100 in the first embodiment. However, in the comparative example, the whiteout correction coefficient is set to 1.0 for all cases, meaning that neither the toner consumption nor the notification threshold is corrected. Table 2 shows a list of the whiteout correction coefficient settings and evaluation results for the comparative example. [Table 2]

[0108] (2) First and Third Examples Table 3 shows a list of the correction coefficient settings and evaluation results for the first and third embodiments. Note that the multiplication of the toner consumption by the whiteout correction coefficient C in the first embodiment acts substantially similarly to the division of the notification threshold by the threshold correction coefficient in the third embodiment. Therefore, the evaluation results for the first and third embodiments are shown together here. [Table 3]

[0109] (3) Second Example Table 4 shows a list of the correction coefficient settings and evaluation results for the second embodiment. [Table 4]

[0110] <8-4. Discussion> First, focusing on configuration T1, no white spots were observed in the comparative example and all of the first to third embodiments, and the image quality was good. This means that the notification prompting the replacement of the regeneration unit was not too late. In configuration T1, the toner is genuine, and both the developing roller and the supply roller are genuine new products, resulting in proper toner supply performance for the entire unit.

[0111] Next, focusing on configurations T2 to T6 in the comparative example, significant white gaps were observed in all configurations regardless of the operating mode. This indicates that the notification prompting the replacement of the regeneration unit is too late. The reason for the delayed notification is that toner consumption and notification thresholds are not corrected, even though toner, developing rollers, or supply rollers that are inferior in characteristics or performance compared to genuine and new parts are being used.

[0112] Next, focusing on configurations T2 to T6 in the first and third embodiments, no white spots were observed in operating mode M1, and the image quality was good. This means that the notification prompting the replacement of the regeneration unit was timely. The reason the notification was timely is that the toner consumption or notification threshold was corrected according to a correction coefficient C determined in accordance with the decrease in toner supply performance in each configuration, thereby accelerating the timing at which the toner consumption reached the notification threshold. On the other hand, slight white spots were observed in operating mode M2. This is because repeated printing at a low print density over a long period in operating mode M2 ​​led to a greater decrease in toner fluidity compared to operating mode M1, and consequently, the toner supply performance also deteriorated further.

[0113] Next, focusing on configurations T2 to T6 in the second embodiment, no white spots were observed in any configuration regardless of the operating mode, and the image quality was good. This means that the notification prompting the replacement of the regeneration unit was timely. In particular, the reason why even minor white spots were not observed in operating mode M2 ​​is that the effect of fogging during printing at low print density on toner consumption was captured by an independent fogging correction coefficient and reflected in the estimated value of toner consumption.

[0114] The results of the verification experiments described above confirmed that the first, second, and third embodiments are effective in optimizing the timing for prompting users to replace remanufactured image forming units, and that the second embodiment shows particularly excellent results.

[0115] <9. Variation> Various modifications can be conceived of the embodiments and examples described above.

[0116] <9-1. First variation> As a first modification, the correction of toner consumption in non-image areas using the fogging correction coefficient in the second embodiment may be performed in the third embodiment. In this case, the notification control unit 122 estimates a first consumption component based on the number of exposed pixels, estimates a second consumption component based on the number of unexposed pixels, and corrects the second consumption component according to the fogging correction coefficient. The notification control unit 122 also estimates toner consumption by summing the first consumption component and the corrected second consumption component. The notification control unit 122 then controls the notification means to notify the user when it is determined that the estimated toner consumption has reached a notification threshold corrected according to the threshold correction coefficient.

[0117] In the first modified example, the notification timing can be changed to compensate for differences in toner supply performance by correcting the notification threshold to match the performance or characteristics of the components constituting the remanufactured image forming unit. In addition, by using an independent correction coefficient for toner consumption caused by "fogging," the difference in the degree of toner degradation caused by differences in print density can be reflected in the determination of the notification timing.

[0118] <9-2. Second variation> The technology disclosed herein is also applicable to image forming apparatuses that have a function to measure physical attributes dependent on the remaining amount of toner contained in the image forming unit. As a second modification, an apparatus that estimates toner consumption by taking into account the measurement results of physical attributes dependent on the remaining amount of toner, in addition to the video count value described above, will be described.

[0119] Figure 9 is a schematic cross-sectional view showing an example of the overall configuration of the image forming apparatus 200 according to the second modified example. The image forming apparatus 200 is an image forming apparatus in which the image forming unit is detachably mounted.

[0120] Referring to Figure 9, the image forming apparatus 200 comprises an exposure unit 3, an image forming unit 60, a paper feed tray 20, a transport path 25, a transfer roller 30, a fixing unit 40, an output tray 45, a measuring unit 50, and a controller 210. The image forming unit 60 includes a photoreceptor 1, a charging roller 2, a developing unit 64, and a cleaning unit 8. The developing unit 64 has a supply roller 5, a regulating blade 6, a developing roller 7, a toner storage section 11, a stirrer 12, and a light transmission section 65. Together with the exposure unit 3 and the transfer roller 30, the image forming unit 60 functions as an image forming means for forming an image on a sheet based on input image data. The image forming apparatus 200 further includes a power supply (not shown).

[0121] The measurement unit 50 is a measuring means for measuring a physical attribute that depends on the remaining amount of toner in the toner storage section 11 of the developing unit 64. In this embodiment, the measurement unit 50 measures the light shielding rate of the toner in the toner storage section 11 as a physical attribute that depends on the remaining amount of toner.

[0122] For example, the measuring unit 50 includes a light-emitting element that emits light into the internal space of the toner storage unit 11 via the light-transmitting section 65 of the developing unit 64, a light-receiving element that receives the light that has passed through the internal space of the toner storage unit 11 via the light-transmitting section 65, and a signal processing circuit. While the light-emitting element of the measuring unit 50 continuously emits light for a certain period of time, the agitator 12 agitates the toner in the toner storage unit 11. The measuring unit 50 then calculates the light-shielding rate of the toner by subtracting from 1 the ratio of the amount of light received by the light-receiving element (integral value of the detected light intensity) to the amount of light emitted. As the amount of toner remaining in the toner storage unit 11 decreases, the time for which the toner shields light decreases, and as a result the light-shielding rate becomes smaller. Therefore, the light-shielding rate of the toner measured by the method described above can be used as an indicator of the remaining amount of toner.

[0123] Furthermore, the physical attributes that depend on the remaining toner amount are not limited to the light-shielding rate of the toner as described above. For example, the measurement unit 50 may measure the capacitance between a pair of electrodes arranged in the toner storage section 11 as a physical attribute that depends on the remaining toner amount. Alternatively, the measurement unit 50 may measure the weight of the image forming unit 60 as a physical attribute that depends on the remaining toner amount, using a load sensor arranged at a position where the load is applied to the image forming unit 60.

[0124] Figure 10 is a block diagram showing an example of the configuration of the controller 210 and related units of the image forming apparatus 200. Referring to Figure 10, the controller 210 includes a communication I / F 111, a connection I / F 212, an operation I / F 113, a printer I / F 114, a CPU 215, RAM 116, and ROM 117.

[0125] The connection interface 212 is an interface for connecting the controller 210 to the memory device M of the measurement unit 50 and the image forming unit 60. When the image forming unit 60 is installed in the image forming apparatus 200, the connection interface 212 communicates with the memory device M to detect the installation of the image forming unit 60.

[0126] The CPU 215 is a control means that controls the overall functions of the image forming apparatus 200. The CPU 215 can read information from the readable storage area of ​​the memory device M of the image forming unit 60 via the connection I / F 212, and can write information to the writable storage area of ​​the memory device M. In this embodiment, the CPU 215 functions as a print control unit 121 and a notification control unit 222 by executing a computer program loaded from the ROM 117 into the RAM 116.

[0127] When a print job is executed in the image forming apparatus 200, the toner stored in the toner storage unit 11 of the image forming unit 60 is consumed. The memory device M stores status information indicating the cumulative amount of toner consumed in the toner storage unit 11. The notification control unit 222 controls the notification means of the image forming apparatus 200 to notify the user when the cumulative amount of toner consumed reaches a notification threshold.

[0128] More specifically, the notification control unit 222 estimates the toner consumption each time a print job is executed and updates the status information in the memory device M. In this modified example, the notification control unit 222 estimates the toner consumption based not only on the video count value described in the first to third embodiments, but also on the physical attributes of the image forming unit 60 measured by the measurement unit 50.

[0129] The aforementioned physical (e.g., optical) toner level measurement method is known to be able to estimate the remaining toner level with higher accuracy than the video count value method, within a limited numerical range, such as 80% to 20%. Therefore, as an example, the notification control unit 222 may adopt the toner level value based on the measurement result from the measurement unit 50 when the remaining toner level falls within such a numerical range, and adopt the toner level based on the video count value in other cases.

[0130] As another example, when the toner level falls within the above numerical range, the notification control unit 222 may adjust the toner level value based on the video count value (and the corresponding toner consumption value) by an adjustment amount that depends on the difference between the toner level value based on the measurement result by the measurement unit 50 and the toner level value based on the video count value. For example, if the toner level corresponding to the measurement result of physical attributes is greater than the provisional toner level based only on the video count value, the notification control unit 222 may subtract an adjustment amount from the toner consumption amount corresponding to the magnitude of the difference. Alternatively, if the toner level corresponding to the measurement result of physical attributes is smaller than the provisional toner level, the notification control unit 222 may add an adjustment amount to the toner consumption amount corresponding to the magnitude of the difference. If the difference between the provisional toner level and the toner level corresponding to the measurement result of physical attributes is large, the adjustment amount corresponding to the magnitude of the difference may be distributed over multiple toner level information update timings to avoid a sudden change in the toner level value due to the adjustment. For example, if the adjustment amount is distributed over two toner level information update timings, the change in toner level per update can be suppressed by half. Alternatively, the notification control unit 222 may adjust the toner remaining value (and the corresponding toner consumption value) little by little at the timing of each update of the remaining amount information so that the distribution of the adjustment amount is completed when the toner remaining amount reaches 0%.

[0131] The notification control unit 222 determines whether the cumulative toner consumption has reached a notification threshold (or whether the toner level has reached a threshold such as 0%). If the notification control unit 222 determines that the cumulative toner consumption has reached a notification threshold, it causes the notification means to issue a notification prompting the user to replace the image forming unit 60. If the notification control unit 222 determines that the cumulative toner consumption has not reached a notification threshold, it may control the notification means to notify the user of the latest toner level.

[0132] As in this modified example, even when physical remaining toner measurement and remaining toner estimation based on video count values ​​are used in combination, the timing of notification regarding low remaining toner can be optimized by correcting the toner consumption or notification threshold based on remanufacturing information, as in the first to third embodiments.

[0133] <9-3. Third Variation> In the third modification, toner consumption is not estimated based on the video count value; instead, the timing of the notification prompting the user to replace the unit is determined based on the physical remaining toner measurement described in the second modification.

[0134] The image forming apparatus according to the third modified example may be configured in the same manner as the image forming apparatus 200 according to the second modified example. The image forming apparatus 200 includes a measuring unit 50 that measures physical attributes dependent on the remaining amount of toner in the toner storage section 11 of the developing unit 64. The CPU 215 of the controller 210 of the image forming apparatus 200 functions as a print control unit 121 and a notification control unit 222.

[0135] The notification control unit 222 estimates the toner consumption from the results of physical toner level measurements each time a print job is executed and updates the status information in the memory device M. In this modified example, the notification control unit 222 converts the light shielding rate of the toner measured by the measurement unit 50 into the remaining toner amount. The toner consumption corresponds to the decrease in the remaining toner amount.

[0136] As described in the third embodiment, the notification control unit 222 corrects the notification threshold according to a threshold correction coefficient obtained based on the remanufacturing information read from the memory device M. The notification control unit 222 then determines whether the cumulative toner consumption has reached the corrected notification threshold. If the notification control unit 222 determines that the cumulative toner consumption has reached the corrected notification threshold, it causes the notification means to issue a notification prompting the user to replace the image forming unit 60.

[0137] As in this modified example, even when the remaining toner level is estimated solely based on physical measurement, the timing of notifications regarding low toner levels can be optimized by correcting the notification threshold based on remanufacturing information, as in the third embodiment.

[0138] <10. Other Embodiments> The above embodiment can also be implemented in the form of a process in which a program that implements one or more functions is supplied to a system or device via a network or storage medium, and one or more processors in the computer of that system or device read and execute the program. It can also be implemented by a circuit (e.g., an ASIC) that implements one or more functions.

[0139] The disclosures herein include at least the following image forming apparatuses: (Item 1) An image forming apparatus in which an image forming unit is detachably attached, The image forming unit includes a developing means for developing an electrostatic latent image formed on the surface of an image carrier with a developer, a storage means for storing the developer, and a storage means for storing remanufacturing information written during the remanufacturing of the image forming unit. The image forming apparatus is Notification methods, A control means controls the notification means to notify the user when the amount of developer consumed reaches a notification threshold, Equipped with, The control means is Based on the remanufacturing information read from the storage means, at least one correction coefficient is obtained for correcting the parameter used to determine whether the amount of developer consumed has reached the notification threshold. The parameters are corrected according to the obtained at least one correction coefficient. Using the corrected parameters, it is determined whether the amount of developer consumed has reached the notification threshold. Image forming apparatus. (Item 2) The image forming apparatus is Exposure means for forming an electrostatic latent image on the surface of the charged image carrier by exposing the image carrier to input image data, Furthermore, The control means is Based on the input image data, the number of exposed pixels exposed by the exposure means is counted. Based on the number of exposure pixels, the amount of developer consumed is estimated. The at least one correction factor includes a correction factor for correcting the estimated consumption of the developer. The image forming apparatus described in item 1. (Item 3) The control means is Based on the input image data, the number of exposed pixels and the number of unexposed pixels are counted. Based on the number of exposure pixels, the first consumption component is estimated. Based on the number of unexposed pixels, the second consumption component is estimated. By summing the first consumption component and the second consumption component, the amount of developer consumed is estimated. The at least one correction coefficient includes a first correction coefficient for correcting the first consumption component and a second correction coefficient for correcting the second consumption component. The image forming apparatus described in item 2. (Item 4) The image forming apparatus according to item 3, wherein the second correction coefficient is greater than the first correction coefficient. (Item 5) The image forming apparatus is A measuring means for measuring physical attributes that depend on the remaining amount of developer in the storage means. Furthermore, The control means further estimates the amount of developer consumed based on the physical attributes measured by the measuring means. An image forming apparatus as described in any one of items 2 to 4. (Item 6) The at least one correction coefficient includes a third correction coefficient for correcting the notification threshold, The control means is The notification threshold is corrected according to the third correction coefficient. Determine whether the amount of developer consumed has reached the corrected notification threshold. The image forming apparatus described in item 1. (Item 7) The image forming apparatus is Exposure means for forming an electrostatic latent image on the surface of the charged image carrier by exposing the image carrier to input image data, Furthermore, The control means is Based on the input image data, the number of exposed pixels and the number of unexposed pixels exposed by the exposure means are counted. Based on the number of exposure pixels, the first consumption component is estimated. Based on the number of unexposed pixels, the second consumption component is estimated. The two consumption components described above are corrected according to the second correction coefficient. The amount of developer consumed is estimated by summing the first consumption component and the corrected second consumption component. The at least one correction coefficient further includes the second correction coefficient for correcting the second consumption component. The image forming apparatus described in item 6. (Item 8) The image forming apparatus is A measuring means for measuring physical attributes that depend on the remaining amount of developer in the storage means. Furthermore, The control means estimates the amount of developer consumed based on the physical attributes measured by the measuring means. The image forming apparatus described in item 6. (Item 9) The image forming apparatus according to item 5 or 8, wherein the physical attributes measured by the measuring means include at least one of the light shielding rate, capacitance, and weight of the developer in the containment means. (Item 10) The image forming apparatus according to any one of items 1 to 9, wherein the remanufacturing information includes correction factor information indicating at least one correction factor. (Item 11) The remanufacturing information includes configuration information that identifies the components constituting the image forming unit after remanufacturing, The control means obtains the at least one correction coefficient based on the configuration information included in the remanufacturing information. An image forming apparatus as described in any one of items 1 to 9. (Item 12) The developing means includes a developing roller that supplies the developer to the electrostatic latent image, and a supply roller that supplies the developer from the storage means to the developing roller. The value of the at least one correction coefficient is determined based on one or more of the performance of the developing roller, the performance of the supply roller, and the characteristics of the developer. An image forming apparatus as described in item 10 or 11. (Item 13) The image forming apparatus according to any one of items 1 to 12, wherein the notification means includes at least one of a display for visual notification, a speaker for auditory notification, and a communication interface for transmitting notification messages to an external device.

[0140] The invention is not limited to the embodiments described above, and various modifications and variations are possible without departing from the spirit and scope of the invention. Accordingly, claims are attached to disclose the scope of the invention. [Explanation of symbols]

[0141] 1: Photoreceptor (image carrier), 2: Charging roller, 3: Exposure unit, 4, 64: Developing unit, 5: Supply roller, 6: Regulating blade, 7: Developing roller, 8: Cleaning unit, 9: Cleaning blade, 10, 60: Image forming unit (process cartridge), 11: Toner storage unit, 13: Waste toner storage unit, 20: Paper feed tray, 25: Transport path, 30: Transfer roller, 40: Fixing unit, 45: Discharge tray, 50: Measurement unit, 65: Light transmission unit, 70: Operation unit, 100, 200: Image forming apparatus, 110, 210: Controller, 111: Communication interface, 112, 212: Connection interface, 121: Printing control unit, 122, 222: Notification control unit, M: Memory device, M1: Original information area, M2: Remanufacturing information area, M3: Status information area

Claims

1. An image forming apparatus in which an image forming unit is detachably attached, The image forming unit includes a developing means for developing an electrostatic latent image formed on the surface of an image carrier with a developer, a storage means for storing the developer, and a storage means for storing remanufacturing information written during the remanufacturing of the image forming unit. The image forming apparatus is Notification methods, A control means controls the notification means to notify the user when the amount of developer consumed reaches a notification threshold, Equipped with, The control means is Based on the remanufacturing information read from the storage means, at least one correction coefficient is obtained for correcting the parameter used to determine whether the amount of developer consumed has reached the notification threshold. The parameters are corrected according to the obtained at least one correction coefficient. Using the corrected parameters, it is determined whether the amount of developer consumed has reached the notification threshold. Image forming apparatus.

2. The image forming apparatus is Exposure means for forming an electrostatic latent image on the surface of the charged image carrier by exposing the charged image carrier to input image data, Furthermore, The control means is Based on the input image data, the number of exposed pixels exposed by the exposure means is counted. Based on the number of exposure pixels, the amount of developer consumed is estimated. The at least one correction factor includes a correction factor for correcting the estimated consumption of the developer. The image forming apparatus according to claim 1.

3. The control means is Based on the input image data, the number of exposed pixels and the number of unexposed pixels are counted. Based on the number of exposure pixels, the first consumption component is estimated. Based on the number of unexposed pixels, the second consumption component is estimated. By summing the first consumption component and the second consumption component, the amount of developer consumed is estimated. The at least one correction coefficient includes a first correction coefficient for correcting the first consumption component and a second correction coefficient for correcting the second consumption component. The image forming apparatus according to claim 2.

4. The image forming apparatus according to claim 3, wherein the second correction coefficient is greater than the first correction coefficient.

5. The image forming apparatus is A measuring means for measuring physical attributes that depend on the remaining amount of developer in the storage means. Furthermore, The control means further estimates the amount of developer consumed based on the physical attributes measured by the measuring means. The image forming apparatus according to claim 2.

6. The at least one correction coefficient includes a third correction coefficient for correcting the notification threshold, The control means is The notification threshold is corrected according to the third correction coefficient. Determine whether the amount of developer consumed has reached the corrected notification threshold. The image forming apparatus according to claim 1.

7. The image forming apparatus is Exposure means for forming an electrostatic latent image on the surface of the charged image carrier by exposing the charged image carrier to input image data, Furthermore, The control means is Based on the input image data, the number of exposed pixels and the number of unexposed pixels exposed by the exposure means are counted. Based on the number of exposure pixels, the first consumption component is estimated. Based on the number of unexposed pixels, the second consumption component is estimated. The second consumption component is corrected according to the second correction coefficient. The amount of developer consumed is estimated by summing the first consumption component and the corrected second consumption component. The at least one correction coefficient further includes the second correction coefficient for correcting the second consumption component. The image forming apparatus according to claim 6.

8. The image forming apparatus is A measuring means for measuring physical attributes that depend on the remaining amount of developer in the storage means. Furthermore, The control means estimates the amount of developer consumed based on the physical attributes measured by the measuring means. The image forming apparatus according to claim 6.

9. The image forming apparatus according to claim 5 or 8, wherein the physical attributes measured by the measuring means include at least one of the light shielding rate, capacitance, and weight of the developer in the containment means.

10. The image forming apparatus according to claim 1, wherein the remanufacturing information includes correction coefficient information indicating the at least one correction coefficient.

11. The remanufacturing information includes configuration information that identifies the components constituting the image forming unit after remanufacturing, The control means obtains the at least one correction coefficient based on the configuration information included in the remanufacturing information. The image forming apparatus according to claim 1.

12. The developing means includes a developing roller that supplies the developer to the electrostatic latent image, and a supply roller that supplies the developer from the storage means to the developing roller. The value of the at least one correction coefficient is determined based on one or more of the performance of the developing roller, the performance of the supply roller, and the characteristics of the developer. The image forming apparatus according to claim 10 or 11.

13. The image forming apparatus according to claim 1, wherein the notification means includes at least one of a display for visual notification, a speaker for audible notification, and a communication interface for transmitting notification messages to an external device.

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