Image forming device

Abstract

To provide an image forming apparatus that can reduce the amount of residual toner during replacement of a toner bottle.SOLUTION: When a toner bottle is replaced in a scheduled replacement period prior to an expiration period in which toner in the toner bottle mounted in an image forming apparatus is used up (S1113: YES), the image forming apparatus increases the amount of toner supplied from the toner bottle to a sub hopper (S1114), increases a set value of the concentration of toner in a developing device (S1115), increases the frequency of executing image stabilization processing (S1116), and increases the frequency of discarding deteriorated toner from the developing device (S1117), and thereby can reduce a toner remaining in the toner bottle in the scheduled replacement period for the toner bottle.SELECTED DRAWING: Figure 11

Description

[Technical Field]

[0001] The present disclosure relates to an image forming apparatus, and more particularly to a technique for reducing toner remaining in a toner bottle and being wasted when the toner bottle is replaced. [Background technology]

[0002] In recent years, image forming apparatuses capable of forming images on recording materials such as paper, such as printers, copiers, facsimile machines, and multifunction machines that combine these functions, have become widespread and are used in a variety of situations. In particular, electrophotographic image forming apparatuses have high productivity and excellent image quality.

[0003] Such electrophotographic image forming devices are equipped with a toner bottle, and the image forming device forms images using toner supplied from the toner bottle. When the toner bottle becomes empty after repeated image formation, it is replaced with a new toner bottle.

[0004] The image forming device cannot be used from the time the toner bottle is emptied until it is replaced with a new one. In particular, in a color image forming device that uses multiple colors of toner, the toner bottle replacement period differs for each toner color, so the toner bottle needs to be replaced more frequently than in a monochrome image forming device. If the toner bottle replacement frequency is high, the image forming device will be unavailable for a long period of time while the toner bottle is being replaced, which is particularly likely to impair user convenience.

[0005] To address this issue, a technology has been developed to predict when a toner bottle will be empty. For example, a technology has been proposed that predicts when a toner bottle will be empty by estimating the amount of toner remaining in the toner bottle using the cumulative toner transport time, which is the cumulative value of the time it takes to supply toner from the toner bottle.

[0006] Even if the cumulative toner transport time is the same, the longer the time during which toner is continuously transported within the cumulative toner transport time, the more efficient the toner transport and the greater the amount of toner transported, which tends to result in the toner bottle becoming empty sooner.

[0007] Furthermore, the higher the humidity inside the image forming apparatus, the lower the fluidity of the toner, and the larger the toner lumps that are transported together, so the toner bottle also tends to run out sooner.

[0008] Taking such trends into consideration, it is possible to improve the accuracy of predicting when a toner bottle will become empty (see Patent Document 1).

[0009] By predicting the time when the toner bottle will become empty in this way, a replacement toner bottle can be obtained or a maintenance service for replacing the toner bottle can be requested before the time when the toner bottle becomes empty, so that the period during which the image forming apparatus cannot be used can be kept to a minimum, and therefore, convenience for the user can be ensured. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-65003 Summary of the Invention [Problem to be solved by the invention]

[0011] Any prediction is subject to prediction error, and predicting when a toner bottle will run out is no exception. Therefore, it is likely that the toner bottle will run out at a time within the range of prediction error, including the predicted time.

[0012] In other words, the time when the toner bottle actually becomes empty may be earlier than the predicted time within the margin of error, and the image forming device may be unusable for a longer period within the margin of error.

[0013] To cope with this problem, if the toner bottle is replaced at the earliest time within the margin of error before the time when the toner bottle is predicted to become empty, the period during which the image forming apparatus cannot be used due to the replacement of the toner bottle can be reliably shortened to the minimum necessary.

[0014] However, if the toner bottle is replaced at the earliest time within the margin of error before the time when the toner bottle is predicted to be empty, the toner bottle removed from the image forming device may not be completely empty and may still contain usable toner.

[0015] The toner bottle removed from the image forming apparatus is either discarded as is or reused after cleaning, but in either case, the residual toner is discarded.

[0016] Discarding usable toner is both economically and environmentally undesirable since it wastes resources.

[0017] The present disclosure has been made in consideration of the above-mentioned problems, and aims to provide an image forming apparatus that can reduce the amount of residual toner when replacing a toner bottle. [Means for solving the problem]

[0018] In order to achieve the above object, an image forming apparatus according to one aspect of the present disclosure is an electrophotographic image forming apparatus having a detachable toner bottle and a prediction unit for predicting when the toner stored in the toner bottle will be used up when the toner bottle is attached, the image forming apparatus including: an acquisition unit for acquiring a planned replacement time for the toner bottle; and an increase unit for increasing the amount of toner supplied from the toner bottle so that the toner will be used up earlier than the planned replacement time when the toner bottle is used up, if the planned replacement time for the toner bottle precedes the toner bottle's consumption time. a developing means for developing an electrostatic latent image when forming an image by an electrophotographic method; a sub-hopper for temporarily storing toner supplied from a toner bottle and supplying the toner to the developing means; and a sensor for detecting when the toner level in the sub-hopper has dropped to a predetermined level. Equipped with The increasing means increases the amount of toner supplied from the toner bottle to the sub-hopper and also increases the amount of toner supplied from the sub-hopper to the developing means, and the prediction means makes the prediction in response to the detection by the sensor, and then the increasing means increases the amount of toner. It is characterized by:

[0019] In this case, the device may be provided with a receiving means for receiving an instruction as to whether or not to increase the amount of toner supplied from the toner bottle, and a prohibiting means for prohibiting the increasing means from increasing the amount of toner when the receiving means receives a negative instruction.

[0021] Also ,before The above-mentioned means of increasing , the above From Nerbottle The aforementioned Supply toner to the sub-hopper When the amount of toner to be used is increased from the normal amount after replacing the toner bottle, You may do so.

[0022] Also, The aforementioned Toner density in the developing means becomes a target density, The aforementioned From the sub hopper The aforementioned A first control means for supplying toner to the developing means Steps The increasing means comprises: The aforementioned The target concentration in the first control means may be increased.

[0024] The increasing means may increase the operation of consuming toner more than when the toner consumption time is predicted.

[0025] Also, image stabilization means for executing image stabilization processing to stabilize the quality of the formed image. Equipped with The increasing means may increase the frequency at which the image stabilization means executes the image stabilization process.

[0026] Also , the above The developing means has a discharge means for discharging the deteriorated toner, and the increasing means The aforementioned The amount of deteriorated toner discharged by the discharge means may be increased.

[0027] The increasing unit may increase the amount of toner within a range that will prevent the toner from being used up earlier than the scheduled replacement time.

[0028] The prediction means may predict the consumption time using one or more of image coverage, double-sided ratio, P / J, PV, temperature, humidity, and paper size.

[0029] The acquisition means may also include a notification means for notifying the intended replacement date of the consumption date, and may acquire the intended replacement date determined by the intended replacement date according to the consumption date as the intended replacement date. [Effects of the Invention]

[0030] In this way, the amount of toner supplied from the toner bottle is increased before the toner bottle is replaced, so that the amount of toner remaining in the toner bottle when the toner bottle is replaced can be reduced. [Brief explanation of the drawings]

[0031] [Figure 1] 1 is a system configuration diagram showing a main configuration of a maintenance service system 1 according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is a sequence diagram illustrating a typical operation of the maintenance service system 1. [Figure 3] FIG. 2 is an external perspective view showing the main configuration of the image forming apparatus 100. [Figure 4] FIG. 2 is a schematic diagram showing the main internal configuration of the image forming apparatus 100. [Figure 5] 1 is a diagram showing the main configuration of a toner supply system from a toner bottle 300 to a developing device 443 via a sub-hopper 470. FIG. [Figure 6] FIG. 2 is an external perspective view showing the main components of the image forming apparatus 100 related to the toner bottles 300Y, 300M, 300C, and 300K. [Figure 7] FIG. 10 is a diagram showing the main configuration of a sub-hopper 470. [Figure 8] 10(a) to 10(c) are diagrams illustrating the operating state of the sub-hopper 470 according to the height of the top surface of the toner. [Figure 9] FIG. 2 is a diagram showing the main internal configuration of a developing device 443. [Figure 10] FIG. 3 is a block diagram showing the main components of a control unit 321. [Figure 11]10 is a flowchart illustrating a process executed by image forming apparatus 100 to reduce the amount of toner remaining in toner bottle 300 when toner bottle 300 is replaced. [Figure 12] 10 is a graph illustrating a process for estimating when the toner bottle 300 will be consumed. [Figure 13] 10 is a graph showing an example of when the toner bottle 300 will be consumed and when it will be replaced. DETAILED DESCRIPTION OF THE INVENTION

[0032] Hereinafter, an embodiment of an image forming apparatus according to the present disclosure will be described with reference to the drawings. [1] Maintenance service system for image forming devices First, a maintenance service system for an image forming apparatus according to this embodiment will be described.

[0033] 1, the maintenance service system 1 connects an image forming apparatus 100 and a maintenance service center 110 so that they can communicate with each other via a communication network 120. The communication network 120 may include, for example, the Internet.

[0034] A toner bottle containing toner used to form images is detachably attached to image forming apparatus 100. When the toner contained in the toner bottle runs out, image forming apparatus 100 can no longer form images, so the empty toner bottle must be replaced with a new toner bottle.

[0035] However, if a new toner bottle is ordered after the toner bottle is empty, the image forming apparatus 100 cannot be used until the toner bottle is replaced. To minimize this period of time during which the image forming apparatus 100 cannot be used, the image forming apparatus 100 has a function for ordering a new toner bottle before the toner bottle is empty.

[0036] Specifically, as shown in FIG. 2, the image forming device 100 estimates the time when the toner bottle will be empty (hereinafter referred to as the "expiry time") based on the remaining amount of toner contained in the toner bottle, and notifies the maintenance service center 110 of the expiry time via the communication network 120.

[0037] When maintenance service center 110 receives notification of the toner bottle consumption time from image forming device 100, it arranges for a replacement toner bottle or a service technician as preparation work for replacing the toner bottle, and determines the planned time for replacing the toner bottle of image forming device 100 (hereinafter referred to as the "planned replacement time"). Maintenance service center 110 notifies image forming device 100 of the decided planned replacement time.

[0038] When image forming apparatus 100 receives notification of the planned replacement time from maintenance service center 110, it compares the consumption time with the planned replacement time. If the planned replacement time is earlier than the consumption time, the amount of toner supplied from the toner bottle is increased to reduce the amount of toner remaining in the toner bottle at the time of replacement.

[0039] Instead of the maintenance service center 110, the user of the image forming device 100 may contact the service center to obtain information on when a service technician will be dispatched and when a replacement toner bottle will be delivered, and then input these information into the image forming device as the planned replacement time. [2] Configuration of image forming apparatus 100 Next, the configuration of the image forming apparatus 100 will be described.

[0040] As shown in FIG. 3, image forming apparatus 100 is a so-called tandem color multi-function peripheral (MPF), and is composed of an image reading unit 310, an image forming unit 320, a paper feeding unit 330, an operation panel 340, and the like.

[0041] The image reading unit 310 uses a light source (not shown) to illuminate the surface of the document to be read, and generates image data by converting the reflected light into an electrical signal using a CCD (Charge Coupled Device) image sensor (not shown).

[0042] In this case, the reflected light may be separated into three colors, red (R), green (G), and blue (B), to generate image data for each of the RGB colors, or monochrome image data may be generated without color separation. The image data generated by the image reading unit 310 is stored in, for example, the control unit 321 of the image forming unit 320.

[0043] The image forming unit 320 uses image data generated by the image reading unit 310 or image data received from another device such as a personal computer for the image.

[0044] When the image data used for image formation is RGB (Red, Green, and Blue) color image data, the image forming unit 320 converts it into image data for each reproduction color of cyan (C), magenta (M), yellow (Y), and black (K). Positional deviation may also be corrected.

[0045] Toner bottles 300Y, 300M, 300C, and 300K, which contain two-component developers containing toner of each color, Y (Yellow), M (Magenta), C (Cyan), and K (Black), and a carrier, are detachably attached to image forming unit 320. Image forming unit 320 forms a toner image using the toner supplied from toner bottles 300Y, 300M, 300C, and 300K.

[0046] Manual feed tray 322 provided in image forming unit 320 can hold a stack of recording sheets when pulled down to the side of image forming apparatus 100. When manual feed tray 322 is not in use, it can be closed as shown in FIG. 2 to save space.

[0047] Image forming unit 320 transfers a toner image onto a recording sheet supplied from manual feed tray 322 and paper feed unit 330. The recording sheet on which the image has been formed is then discharged onto paper discharge tray 323.

[0048] It should be noted that paper feed unit 330 is equipped with multiple paper feed trays, and each paper feed tray can accommodate a different type of recording sheet. It goes without saying that the number of paper feed trays equipped in paper feed tray 330 is not limited to multiple, and may be one. Furthermore, manual feed tray 322 may be omitted from image forming unit 320.

[0049] The control unit 321 monitors and controls the operation of each unit of the image forming apparatus 100. The control unit 321 also estimates when toner will be consumed and notifies the maintenance service center 110 of this, and receives notification from the maintenance service center 110 of the planned replacement time, and adjusts the amount of toner supplied from the toner bottle.

[0050] Operation panel 340 is disposed on the upper front surface of image forming apparatus 100, and under the control of control unit 321, presents information to a user of image forming apparatus 100 and receives instruction inputs from the user.

[0051] As shown in FIG. 4, a toner counter 341 may be provided on the operation panel 340 to display information such as the planned replacement time for each of the toner bottles 300Y, 300M, 300C, and 300K, the cumulative number of prints, and other information that serves as an indication of the next planned replacement time for each of the toner bottles 300Y, 300M, 300C, and 300K. [3] Configuration of image forming unit 320 Next, the configuration of image forming unit 320 will be mainly described with reference to Fig. 4. Note that, in Fig. 4, for the sake of simplicity, only one paper feed tray constituting paper feed unit 330 is shown, and other paper feed trays are omitted.

[0052] The image forming unit 320 includes image forming units 441Y, 441M, 441C, and 441K. The image forming units 441Y, 441M, 441C, and 441K are arranged in order below the intermediate transfer belt 453 at predetermined intervals.

[0053] Imaging units 441Y, 441M, 441C and 441K are respectively equipped with developing devices 443Y, 443M, 443C and 443K, photosensitive drums 444Y, 444M, 444C and 444K, charging devices 445Y, 445M, 445C and 445K, exposure devices 446Y, 446M, 446C and 446K, and cleaning devices 447Y, 447M, 447C and 447K.

[0054] Imaging units 441Y, 441M, 441C and 441K are arranged along the outer periphery of photosensitive drums 444Y, 444M, 444C and 444K in the rotational direction of photosensitive drums 444Y, 444M, 444C and 444K, in the following order: charging devices 445Y, 445M, 445C and 445K; exposure devices 446Y, 446M, 446C and 446K; developing devices 443Y, 443M, 443C and 443K; and cleaning devices 447Y, 447M, 447C and 447K.

[0055] During image formation, charging devices 445Y, 445M, 445C and 445K uniformly charge the outer circumferential surfaces of photosensitive drums 444Y, 444M, 444C and 444K.

[0056] Control unit 321 inputs image signals, obtained by reading out image data for each scan line, as drive signals for light-emitting diodes to exposure devices 446Y, 446M, 446C, and 446K. As a result, exposure devices 446Y, 446M, 446C, and 446K expose the outer circumferential surfaces of photosensitive drums 444Y, 444M, 444C, and 444K to light in accordance with the image signals to form electrostatic latent images.

[0057] Developing devices 443Y, 443M, 443C and 443K supply toner of each color of YMCK onto the outer circumferential surfaces of photosensitive drums 444Y, 444M, 444C and 444K to develop the electrostatic latent images and form toner images of each color of YMCK.

[0058] Primary transfer rollers 442Y, 442M, 442C and 442K are disposed at positions facing the photosensitive drums 444Y, 444M, 444C and 444K with the intermediate transfer belt 453 interposed therebetween.

[0059] Primary transfer rollers 442Y, 442M, 442C and 442K electrostatically transfer the YMCK toner images carried by photosensitive drums 444Y, 444M, 444C and 444K onto intermediate transfer belt 453 so that they overlap each other (primary transfer).

[0060] In this way, a color toner image is formed. When a monochrome toner image is formed, only the image forming unit 441K forms a toner image and transfers it onto the intermediate transfer belt 453 as a primary transfer.

[0061] After the primary transfer, cleaning devices 447Y, 447M, 447C, and 447K expose the outer peripheral surfaces of photosensitive drums 444Y, 444M, 444C, and 444K to light to remove residual charge, and also scrape off and discard toner remaining on the outer peripheral surfaces of photosensitive drums 444Y, 444M, 444C, and 444K.

[0062] Intermediate transfer belt 453 is an endless belt made of a resin material such as polycarbonate, polyimide, or polyimideamide, and is stretched over drive roller 451 and driven roller 452. Driven roller 452 is biased in a direction away from drive roller 451 by a biasing means (spring) (not shown), thereby applying tension to intermediate transfer belt 453.

[0063] The control unit 321 controls the primary transfer motor 454, thereby driving the drive roller 451 to rotate, and the intermediate transfer belt 453 rotates in the direction of arrow A. As a result, the toner image carried by the intermediate transfer belt 453 is transported to the secondary transfer nip 456.

[0064] In parallel with this, recording sheets are fed one by one from a stack of recording sheets stored in paper feed tray 461 and transported to the transport path indicated by dashed line B. The transport timing of the recording sheets is adjusted by timing roller 457, and then the recording sheets are transported to secondary transfer nip 456.

[0065] Secondary transfer roller 55 is pressed against drive roller 451 with intermediate transfer belt 453 sandwiched therebetween, thereby forming secondary transfer nip 456. The toner image carried on intermediate transfer belt 453 is electrostatically transferred (secondary transfer) to the recording sheet at secondary transfer nip 456. Thereafter, the recording sheet is transported to fixing device 480, where the toner image is thermally fixed, and then the recording sheet is discharged onto discharge tray 323 outside the apparatus.

[0066] After the secondary transfer, the toner remaining on the intermediate transfer belt 453 is scraped off by a cleaner 401 and collected in a waste toner box 402 .

[0067] Furthermore, line sensor 432 detects the toner image carried on intermediate transfer belt 453 on the toner image transport path from the primary transfer nip formed by pressure contact between photosensitive drum 444K of image forming unit 441K and primary transfer roller 442K to secondary transfer nip 456. The detection result of line sensor 432 is used for image stabilization processing.

[0068] In the following, in order to explain the configuration common to each of the YMCK colors, the letters YMCK will be omitted from the symbols.

[0069] In image forming apparatus 100, sub-hopper 470 is disposed below toner bottle 300. Sub-hopper 470 receives toner from toner bottle 300, temporarily stores the toner, and supplies a fixed amount of toner to developing device 443 via supply pipe 471.

[0070] Some image forming apparatuses do not have a sub-hopper 470, but supply toner directly from toner bottle 300 to developing device 443. In such image forming apparatuses, it is difficult to precisely control the amount of toner supplied to developing device 443, and it is also difficult to control the toner concentration in developing device 443 with high precision, so they are not suited to maintaining a stable high image quality.

[0071] On the other hand, if sub-hopper 470 is provided, the amount of toner supplied to developing device 443 can be controlled with high precision, as will be described later, and high image quality can be stably maintained.

[0072] When the amount of toner remaining in the sub-hopper 470 becomes low, toner is supplied from the toner bottle 300 to the sub-hopper 470. When the toner in the toner bottle 300 runs out, it is replaced with a new toner bottle 300. [4] Toner supply configuration The configuration for supplying toner from toner bottle 300 to developing device 443 will be described in more detail below. (4-1) Toner Bottle 300 5, toner bottle 300 includes bottle portion 502 that stores toner, cap portion 503 having toner supply port 503a formed on the outer circumferential surface, and shutter portion 505 that opens and closes supply port 503a. Bottle portion 502 is attached to cap portion 503 so as to be rotatable relative to the cap portion 503.

[0073] When the toner bottle 300 is attached to the image forming apparatus 100, the bottle portion 502 is connected to the driving source 501 via the connecting mechanism 501a, and when the driving source 501 drives the bottle portion 502 to rotate, the toner contained in the bottle portion 502 is transported to the cap portion 503.

[0074] 6, the image forming apparatus 100 includes two sets of drive sources 501 and coupling mechanisms 501a. Of the two sets of drive sources 501 and coupling mechanisms 501a, one of the drive sources 501 and coupling mechanisms 501a drives to rotate the toner bottles 300Y and 300M.

[0075] The other drive source 501 and coupling mechanism 501a rotate the toner bottles 300C and 300K. The coupling mechanism 501a has a clutch mechanism, which allows the drive source 501 to selectively rotate only one of the two bottle portions 502.

[0076] A spiral groove 507 is formed in the bottle part 502, and the spiral groove 507 protrudes toward the inner peripheral surface of the bottle part 502. When the drive source 501 drives and rotates the bottle part 502, the toner contained in the bottle part 502 is transported along the spiral groove 507 and led to the cap part 503.

[0077] Cap portion 503 is provided with toner supply port 503a, which is opened and closed by shutter portion 505. When shutter portion 505 is retracted and toner supply port 503a is open, toner that reaches cap portion 503 passes through toner supply port 503a and falls into sub-hopper 470.

[0078] A knob 504 is provided on the end of the toner bottle 300 on the cap portion 503 side, and by turning the knob 504, the bottle portion 502 can be rotated. (4-2) Subhopper 470 7, a float member 514 that detects the top surface level of the toner is provided inside sub-hopper 470. Float member 514 is provided so as to be able to swing freely around shaft 514a. A cam 512 is provided below float member 514.

[0079] Cam 512 is attached to agitation shaft 511a together with agitation plate 511, and as shown in Fig. 5, agitation shaft 511a is rotationally driven by drive source 521 via connection mechanism 521a. As drive source 521, for example, a stepping motor can be used.

[0080] When drive source 521 rotates agitation shaft 511a, cam 512 rotates, causing float member 514 to swing up and down, and agitation plate 511 rotates, causing the toner stored in sub-hopper 470 to be agitated.

[0081] As shown in Figure 7, a float 514b is attached to the free end of float member 514, and moves up and down following the level of the top surface of the toner. A magnet 514c is attached to the top surface of float 514b. Meanwhile, an empty sensor 515 that detects the magnetic field strength is attached to the outer surface of sub-hopper 470. A reed switch, for example, may be used as empty sensor 515.

[0082] As the float 514b moves up and down, the magnet 514c moves up and down, and as it moves away from the empty sensor 515, the magnetic field strength of the magnet 514c acting on the empty sensor 515 weakens, and as it moves closer to the empty sensor 515, the magnetic field strength strengthens. In this way, the empty sensor 515 turns on and off depending on the magnetic field strength, thereby detecting the top surface level of the toner.

[0083] 8(a), (b), and (c) show the swinging state of float member 514 for each amount of toner stored in sub-hopper 470. When there is a sufficient amount of toner in sub-hopper 470 and the top surface level of the toner is high, float member 514 swings upward as float body 514b rises upward, regardless of the rotation state of cam 512, and magnet 514c moves away from empty sensor 515, turning empty sensor 515 OFF (FIGS. 8(a) and 8(b)).

[0084] On the other hand, when the amount of toner in the sub-hopper 470 becomes low, the top surface level of the toner drops. Therefore, if the cam 512 is not lifting the float member 514, the float member 514 swings downward as the float body 514b moves downward, and the magnet 514c moves downward and approaches the empty sensor 515, turning on the empty sensor 515 (FIG. 8(c)).

[0085] When the empty sensor 515 turns on, the control unit 321 controls the drive source 501 to rotate the bottle portion 502 of the toner bottle 300 (of the same toner color) corresponding to the sub-hopper 470 whose empty sensor 515 turned on for a predetermined time (e.g., 10 seconds).

[0086] This causes toner to be replenished from toner bottle 300 to sub-hopper 470. When the top surface level of the toner in sub-hopper 470 rises due to toner replenishment, empty sensor 515 turns off.

[0087] In this embodiment, as described below, the amount of toner supplied to the sub-hopper 470 is increased by extending the time for which the bottle portion 502 of the toner bottle 300 is rotated (for example, to 15 seconds), thereby reducing the amount of toner remaining in the toner bottle 300 when the toner bottle 300 is replaced.

[0088] Note that if the amount of toner stored in sub-hopper 470 is too large, the accuracy of estimating the amount of toner in the sub-hopper may decrease. Also, the accuracy of the amount of toner supplied from sub-hopper 470 to developing device 443 may decrease.

[0089] To avoid such problems, it is desirable to set the time for which bottle portion 502 of toner bottle 300 is rotated so as not to accumulate too much toner in sub-hopper 470. Conversely, as much toner as possible may be supplied from toner bottle 300 to sub-hopper 470 within a range that does not cause such problems.

[0090] If the user of image forming apparatus 100 does not form many images and therefore the top surface of the toner in sub-hopper 470 does not drop much, there is a risk that a large amount of toner will remain in toner bottle 300 when toner bottle 300 is replaced, without having the opportunity to supply toner from toner bottle 300 to sub-hopper 470 again until toner bottle 300 is replaced.

[0091] In contrast to this, as will be described later, if as much toner as possible is supplied from toner bottle 300 to sub-hopper 470 at the time notification is received that toner bottle 300 is due to be replaced, even if there is no opportunity to supply toner from toner bottle 300 to sub-hopper 470 again, the amount of toner remaining in toner bottle 300 when toner bottle 300 is replaced can be reduced as much as possible.

[0092] If toner is supplied from the toner bottle 300 to the sub-hopper 470 while the float 514b is lowered, the float 514b may be buried in the toner, which may result in an erroneous detection of the toner amount.

[0093] In contrast, if the control unit 321 controls the drive source 521 to rotate the cam 512 before referring to the detection result of the empty sensor 515, the float member 514 can be swung to move the float 514b to the top surface of the toner, thereby preventing erroneous detection of the toner amount due to the float 514b being buried in the toner.

[0094] 5, coupling mechanism 521a couples both agitation plate 511 and supply roller 513 to drive source 521 and transmits the rotational driving force of drive source 521. Therefore, agitation plate 511 and supply roller 513 are not driven to rotate independently, and whenever one is driven to rotate, the other is also driven to rotate.

[0095] Supply roller 513 is a screw member, and when rotated, sends toner stored in sub-hopper 470 to supply pipe 471. Supply pipe 471 is a tubular member for sending toner from sub-hopper 470 to developing device 443. The toner sent out by supply roller 513 falls through supply pipe 471 by gravity and reaches developing device 443. (4-3) Developing device 443 5, the developing device 443 includes a toner concentration sensor (toner carrier ratio sensor) 431. The toner concentration sensor 431 detects the toner concentration in the developer stored in the developing device 443.

[0096] The toner concentration is the weight of the toner in the two-component developer divided by the weight of the two-component developer, which is equal to the weight of the toner plus the weight of the carrier.

[0097] Toner concentration sensor 431 may measure, for example, the magnetic permeability of an area where toner is present in developing device 443. The carrier contained in two-component developer is mainly composed of iron, and when the magnetic permeability is high, it is considered that there is a lot of carrier, and therefore it can be determined that the toner concentration is low.

[0098] Conversely, when the magnetic permeability is low, it is considered that there is little carrier, and therefore the toner concentration is determined to be high.

[0099] The control unit 321 refers to the toner concentration detected by the toner concentration sensor 431, and if the detected toner concentration becomes lower than a predetermined toner concentration, it controls the drive source 521 to rotate the supply roller 513 of the sub-hopper 470 and supply toner to the developing device 443.

[0100] For example, if the set value of the toner concentration (normally) is 6.5±1.0%, when the toner concentration falls below 5.5%, the supply roller 513 rotates and toner is replenished from the sub-hopper 470 to the developing device 443, and when the toner concentration reaches 6.5%, the rotation of the supply roller 513 stops.

[0101] In addition, since the supply roller 513 sends a predetermined number of grams of toner to the developing device 443 with one rotation, the amount of toner sent to the developing device 443 can be managed by monitoring and controlling the rotation speed of the supply roller 513.

[0102] In this embodiment, prior to replacing toner bottle 300, the toner concentration setting value of developing device 443 is increased (for example, 7.5±1.0%), thereby increasing the amount of toner stored in developing device 443.

[0103] In this way, when toner is supplied from sub-hopper 470 to developing device 443 , the top surface level of the toner in sub-hopper 470 drops, and toner is supplied from toner bottle 300 to sub-hopper 470 .

[0104] Therefore, the amount of toner remaining in the toner bottle 300 when the toner bottle 300 is replaced can be reduced. (4-4) Disposal of toner from developing device 443 In this embodiment, when cam 512 of sub-hopper 470 is driven to rotate by drive source 501, supply roller 513 is also driven to rotate at the same time. For this reason, for example, when determining whether toner bottle 300 is new or not, if cam 512 is rotated before checking the detection result of empty sensor 515, supply roller 513 will also rotate, and toner will be replenished from sub-hopper 470 to developing device 443 regardless of the level of toner concentration in developing device 443.

[0105] If toner is further replenished while the toner concentration setting in the developing device 443 is already high, and the toner concentration in the developing device 443 becomes too high, "fogging" may occur, deteriorating image quality, or the inside of the device may become dirty due to toner scattering.

[0106] Therefore, when it is determined in advance that the toner concentration in the developing device 443 will become too high, it is desirable to discard the toner in the developing device 443 in addition to driving the cam 512 to rotate.

[0107] Specifically, the outer peripheral surface of the photosensitive drum 444 is uniformly charged and exposed to form a solid electrostatic latent image, and the toner in the developing device 443 is discarded onto the photosensitive drum 444 by performing a process to develop the solid electrostatic latent image.

[0108] The discarded toner may be collected by a cleaning device 447, or may be scraped off by a cleaner 401 and collected in a waste toner box 402 after being primarily transferred onto an intermediate transfer belt 453 without being secondarily transferred. (4-5) Disposal of degraded toner In order to discard toner from developing device 443, in addition to using the electrophotographic process as described above, in this embodiment, it is also possible to discard deteriorated toner from developing device 443 by adopting a so-called trickle development method.

[0109] 9, developing device 443 includes a stirring / transporting tank 911 and a supply tank 912. A stirring / transporting screw 531 stirs the developer in stirring / transporting tank 911 and transports it in the direction of arrow C. A supply screw 532 stirs the developer in supply tank 912 and transports it in the direction of arrow D.

[0110] The agitating and transporting tank 911 and the supply tank 912 are separated by a partition wall 913. The partition wall 913 has communication paths (through holes) (not shown) formed at both ends in the developer transport direction, which connect the agitating and transporting tank 911 and the supply tank 912 and allow the developer to flow. The developer is circulated and transported between the agitating and transporting tank 911 and the supply tank 912 in the directions of arrows C and D by passing through these communication paths.

[0111] In this way, the developer is stirred in the stirring and transporting tank 911 and the supply tank 912, so that the toner in the developer can be charged and the developer can be prevented from agglomerating.

[0112] The developing roller 533 rotates with the developer in the supply tank 912 magnetically attracted to its outer surface, thereby supplying the developer in the supply tank 912 to the electrostatic latent image formed on the outer surface of the photosensitive drum 444.

[0113] A discharge section 900 is provided downstream of supply tank 912 in the developer transport direction (direction of arrow D) to discharge a portion of the developer to the outside of developing device 443. Discharge section 900 includes a reverse-winding screw 901 and is provided with a discharge port 902.

[0114] The reverse winding screw 901 shares a common rotation axis with the supply screw 532. The stirring and conveying screw 531, the supply screw 532, and the reverse winding screw 901 are driven by a common drive source and rotate in unison.

[0115] This makes it possible to restrict the developer from flowing from supply tank 912 into discharge section 902. That is, most of the developer transported in the direction of arrow D within supply tank 912 flows into stirring and transporting layer 911 via the communicating passage, and only a portion flows into discharge section 900.

[0116] Discharge port 902 is opened and closed by a shutter (not shown). When discharge port 902 is closed by the shutter, the amount of developer flowing from supply tank 912 to discharge section 900 by supply screw 532 and the amount of developer flowing back from discharge section 900 to supply tank 912 by reverse winding screw 901 are balanced according to the amount of developer in developing device 443.

[0117] Furthermore, when the discharge port 902 is open, the developer in the developing device 443 is discharged to the outside of the image forming device 443 via the discharge port 902, while new developer equivalent to the amount discharged is replenished from a supply port (not shown). In this way, it is possible to discard the toner that has deteriorated by being circulated and transported within the developing device 443. Therefore, it is possible to prevent the occurrence of development defects and deterioration of image quality due to deteriorated toner. (4-6) Toner bottle 300 replacement confirmation process Toner bottle 300 may have been replaced when the front door of image forming apparatus 100 is opened or closed, when the main power is turned on, when the image forming apparatus recovers from a sleep mode that reduces power consumption, etc. In such cases, by rotating bottle portion 502 and checking whether the detection result of empty sensor 515 switches from on to off, it can be determined whether toner bottle 300 has been replaced with a new one.

[0118] If the toner bottle has been replaced with a new one, toner is replenished to sub-hopper 470 when bottle portion 502 is rotated, and empty sensor 515 turns off when control unit 321 rotates cam 512. On the other hand, if there is no toner in toner bottle 300, toner is not replenished to sub-hopper 470 even when bottle portion 502 is rotated, and empty sensor 515 remains on. If empty sensor 515 does not turn off even when bottle portion 502 is rotated for a predetermined time, it can be determined that toner bottle 300 has not been replaced.

[0119] Therefore, when the toner bottle 300 is replaced, the process for reducing the amount of toner remaining in the toner bottle 300 is continued.

[0120] On the other hand, while monitoring the change in the TC ratio using toner concentration sensor 431, if developing device 443 is made to consume toner in excess of the capacity of sub-hopper 470 and the TC ratio does not decrease, it is assumed that toner has been replenished from toner bottle 300 to sub-hopper 470, and if toner bottle 300 was originally empty, it can be determined that toner bottle 300 has been replaced with a new one.

[0121] In this case, the process for reducing the amount of toner remaining in toner bottle 300 is terminated when toner bottle 300 is replaced. Naturally, this allows toner to be saved compared to when the process for reducing the amount of toner remaining in toner bottle 300 is continued when toner bottle 300 is replaced. [5] Configuration of control unit 321 Next, the configuration of the control unit 321 will be described.

[0122] As shown in FIG. 10, the control unit 321 includes a printer controller 1011 and an engine control unit 1021.

[0123] The printer controller 1011 receives an image formation job from a PC (Personal Computer) 1031 via a communication network 120, and instructs an engine control unit 1021 to execute mechanical control for image formation.

[0124] The printer controller 1011 is connected to a ROM (Read Only Memory) 1012, a RAM (Random Access Memory) 1013, a HDD (Hard Disk Drive) 1014, a timer 1015, a NIC (Network Interface Card) 1016, and a facsimile interface (FAX I / F) 1017.

[0125] When the image forming device 100 is powered on, the printer controller 1011 reads and starts a boot program from the ROM 1012, and monitors and controls the operation of each part of the image forming device 100 by executing the OS (Operating System) and control programs read from the HDD 1014 using the RAM 1013 as a working memory area.

[0126] The printer controller 1011 issues control instructions to the engine control unit 1021 via a serial bus 131 and transmits image data to the engine control unit 1021 via an image bus 132 .

[0127] When the printer controller 1011 receives an image formation job from the PC 1031 via the communication network 120, receives facsimile data via the facsimile line 1032, or receives a copy job on the operation panel 340 and generates image data by reading an original document with the image reading unit 310, the printer controller 1011 sends the image data to the engine control unit 1021 to execute the image formation process.

[0128] The ROM 1012 and the HDD 1014 are non-volatile storage media, and the ROM 1012 is superior in terms of transfer speed, while the HDD 1013 tends to be advantageous in terms of storage capacity. The RAM 1013 has an even faster transfer speed than the ROM 1012, and its storage capacity is intermediate between the ROM 1012 and the HDD 1013.

[0129] The NIC 1016 executes processing for communicating with other devices such as the maintenance service center 110 and PC 1031 via the communication network 120. The facsimile interface 1017 executes communication processing for sending and receiving image data by facsimile via a facsimile line 1032.

[0130] Engine control unit 1021 controls toner control unit 1022 and paper feed control unit 1024. Toner control unit 1022 controls the supply of toner from toner bottle 300 to sub-hopper 470 and the supply of toner from sub-hopper 470 to developing device 443 by controlling the drive of toner-related motor 1023a in accordance with control instructions from engine control unit 1021.

[0131] Furthermore, the toner control unit 1022 refers to the detection signal of the toner-related sensor 1023b to notify the engine control unit 1021 of status information related to toner replenishment. The above-mentioned empty sensor 515 and toner concentration sensor 431 are included in the toner-related sensor 1023b.

[0132] The paper feed control unit 1024 executes a conveying process from sending out the recording sheet from the paper feed tray 461 to discharging it outside the apparatus by controlling the driving of the conveyance motor 1025 in accordance with a control instruction from the engine control unit 1021. For this reason, the paper feed control unit 1024 starts and stops the conveyance motor 1025 and monitors its rotation. [6] Processing to reduce the amount of residual toner Next, a process for reducing the amount of toner remaining in toner bottle 300 when toner bottle 300 is replaced will be described.

[0133] As shown in FIG. 11, when the image forming device 100 receives an image forming job from a user via the operation panel 340 or receives an image forming job from another device via the communication network 120 (S1101: YES), the image forming device 100 executes the received image forming job.

[0134] Here, an image forming job is a job that requires image forming processing, such as a print job, a copy job, a facsimile receiving job, etc. When an image forming job is executed, toner is consumed.

[0135] Even if an image formation job has not been accepted (S1101: NO), when the timing for executing the image stabilization process arrives (S1103: YES), the image stabilization process is executed (S1104). Whether or not the timing for executing the image stabilization process has arrived may be determined based on whether or not the cumulative number of images formed has reached a preset cumulative number of images formed. Alternatively, the determination may be made by other methods.

[0136] Image stabilization processing is processing for forming images under various image forming conditions and identifying the image forming conditions that can form images of a predetermined quality. For example, by forming toner patches of various gradations on intermediate transfer belt 453 and transporting them to the reading position of line sensor 432 and detecting the reflection density for each toner patch, it is possible to identify the image forming conditions that will obtain the desired reflection density.

[0137] The image forming conditions include, for example, the charging bias used by the charging device 445 to uniformly charge the outer peripheral surface of the photosensitive drum 444, and the exposure amount used by the exposure device 446 to expose the outer peripheral surface of the photosensitive drum 444 to form an electrostatic latent image.

[0138] Additionally, the developing bias when developing device 443 supplies toner to the electrostatic latent image to develop it, and the primary transfer bias when the primary transfer roller electrostatically transfers the toner image from the outer circumferential surface of photosensitive drum 444 to the outer circumferential surface of intermediate transfer belt 453 also fall under the image formation conditions. In this way, toner is consumed when image stabilization processing is performed.

[0139] Furthermore, even if it is not the timing to perform image stabilization processing (S1103: NO), if the liquid level in sub-hopper 470 has dropped (S1105: YES), toner is replenished from toner bottle 300 to sub-hopper 470 (S1106). Whether the liquid level in sub-hopper 470 has dropped can be determined by referring to the detection signal of empty sensor 515, as described above.

[0140] When toner is consumed by executing an image forming job or image stabilization processing, or when the amount of toner in the toner bottle 300 decreases by supplying toner to the sub-hopper 470, the amount of remaining toner is estimated (S1107).

[0141] The amount of residual toner can be estimated using the cumulative number of dots (hereinafter referred to as the "cumulative dot count") when forming an image of the toner color contained in the toner bottle 300 since the toner bottle 300 was replaced.

[0142] If the amount of toner contained in the new toner bottle 300 is W0, the amount of remaining toner Wr is calculated by the following formula: Wr = W0 - (cumulative number of dots) × K ... (1) where K is a constant for converting the cumulative number of dots into the toner amount.

[0143] 12, by plotting each estimated residual toner amount Wr on a graph with the vertical axis representing the toner amount and the horizontal axis representing time, a line graph 1201 can be obtained. This line graph 1201 is repeatedly plotted until the amount of residual toner in toner bottle 300 becomes zero.

[0144] For example, the least squares method is used to obtain an approximate line 1202 for such a line graph 1201. By extending the approximate line 1202 until the amount of remaining toner becomes zero, it is possible to estimate when the toner will be consumed (S1108).

[0145] There is a residual error 1203 between the approximated line 1202 and the residual toner amount Wr, and the approximated line 1202 is determined so as to minimize the residual sum of squares (RRS) of the residual error 1202. For example, if a user forms images on a small number of sheets at a time and forms images periodically, the residual sum of squares RRS becomes small.

[0146] If the sum of squares of the residuals RRS is small, there is a high probability that the amount of toner remaining in the toner bottle 300 will actually become zero near the time when the toner will be consumed, as estimated using the approximate line 1202. Therefore, the error range 1204 of the time when the toner will be consumed becomes narrow.

[0147] Conversely, if the user forms images on a large number of sheets at one time and there is a large variation in the timing of forming the images, the sum of squares of the residuals RRS will be large, and it is thought that the error range 1204 of the toner consumption timing will be wide.

[0148] In this way, since the size of the error range 1204 is proportional to the RRS of the residuals, the RRS of the residuals may be used to determine the error range 1204. In this embodiment, the error range 1204 is expressed as, for example, "±3 days."

[0149] If the lower limit of the error range 1204 including the time when the toner is consumed is set as the scheduled time to replace the toner bottle 300, the period during which the image forming device 100 cannot be used from when the toner in the toner bottle 300 is used up until the replacement of the toner bottle 300 is completed can be minimized compared to when other points within the error range 1204 are set as the scheduled time to replace the toner bottle 300.

[0150] Next, the period from the present time until the toner runs out is calculated and compared with a predetermined threshold value. This threshold value is preferably a period sufficient to prepare for replacing toner bottle 300. Alternatively, instead of the period from the present time until the toner runs out, the period from the present time to the lower limit of error range 1204 for the toner run out may be used.

[0151] If the time until the toner runs out is longer than the predetermined threshold (S1109: NO), it is too early to start the process of reducing the amount of remaining toner in the toner bottle 300, so the process returns to step S1101 and the above process is repeated.

[0152] If the time until the toner runs out is equal to or less than the predetermined threshold (S1109: YES), it is confirmed whether the replacement schedule for the toner bottle 300 has been acquired from the maintenance service center 110.

[0153] If the replacement schedule has already been obtained from the maintenance service center 110 (S1110: YES), the process of reducing the amount of residual toner in the toner bottle 300 has already started, so the process returns to step S1101 and the above process is repeated.

[0154] If the planned replacement time has not yet been obtained from the maintenance service center 110 (S1110: NO), the image forming device 100 notifies the maintenance service center 110 of the consumption time and the error range (S1111), and waits for notification of the planned replacement time from the maintenance service center 110.

[0155] When the maintenance service center 10 receives the notice of the consumption time and the error range, it arranges for a replacement toner bottle 300 and a serviceman so that the toner bottle 300 can be replaced by the lower limit of the error range as much as possible, and determines the time to replace the toner bottle of the image forming device 100.

[0156] Since it is not always possible to replace the toner bottle 300 by the lower limit of the error range, if the toner bottle 300 cannot be replaced by the lower limit of the error range, it is desirable to arrange for a replacement toner bottle 300 and a service technician and determine the scheduled replacement time for the toner bottle 300 so that the toner bottle 300 can be replaced as soon as possible after the lower limit of the error range.

[0157] Depending on the contents of the maintenance contract and other circumstances, it may be possible to send only the toner bottle 300 to the manager or user of the image forming apparatus 100 without dispatching a service technician. In this case, the scheduled delivery date of the toner bottle 300 becomes the scheduled replacement date. The maintenance service center 110 notifies the image forming apparatus 100 of the determined scheduled replacement date.

[0158] When the image forming apparatus 100 receives notification of the replacement schedule from the maintenance service center 110 (S1112: YES), it compares the consumption time with the replacement schedule to determine which comes first.

[0159] If the planned replacement time is after the consumption time (S1113: NO), increasing the amount of toner supplied from the toner bottle 300 will cause the toner to run out before the toner bottle 300 is replaced, making it impossible to form images.

[0160] Therefore, the process returns to step S1101 and repeats the above process without increasing the amount of toner supplied from toner bottle 300. In this case, it is also possible to execute a process to conserve toner as much as possible, such as lowering the set value of the toner concentration in developing device 443 or reducing the frequency of executing image stabilization processing.

[0161] If the planned replacement time is earlier than the consumption time (S1113: YES), the amount of toner supplied from toner bottle 300 to sub-hopper 470 is increased (S1114). In this way, instead of leaving toner in toner bottle 300, the toner can be stored in sub-hopper 470. Therefore, the amount of toner remaining in toner bottle 300 when toner bottle 300 is replaced can be reduced.

[0162] Also, the set value of the toner concentration in developing device 443 is increased. By doing so, when the amount of toner supplied from sub-hopper 470 to developing device 443 increases, the amount of toner stored in sub-hopper 470 decreases. This makes it easier for toner to be supplied from toner bottle 300 to sub-hopper 470, so the amount of toner remaining in toner bottle 300 can be reduced.

[0163] If the toner concentration in the developing device 443 is set too high (for example, 8.5%), image defects such as fogging in the white background are likely to occur. To prevent such image defects from occurring, the set value (normally) of the toner concentration in the developing device 443 is set with a certain margin relative to the toner concentration at which image defects may occur.

[0164] The toner concentration in developing device 443 decreases when toner is supplied during image formation, and increases when toner is supplied from sub-hopper 470. Taking into consideration such fluctuations in toner concentration, the toner concentration setting value (for normal use) is set with a large margin to allow for some leeway.

[0165] Therefore, within this margin, even if the set value of the toner concentration is somewhat high, it is possible to reduce the amount of residual toner in the toner bottle 300 while avoiding the occurrence of image defects.

[0166] Furthermore, in step S1104, the frequency with which the image stabilization process is executed is increased (S1116).

[0167] In electrophotographic image forming devices, the final image density can change due to changes in the conditions of the photoconductor, developer, and transfer belt as the device is used. Changes in the operating environment, such as temperature and humidity, can also cause the final image density to change. To correct these changes and achieve stable image quality, it is common to perform image stabilization processing at regular intervals.

[0168] Specifically, a predetermined image (toner patch) is formed under a plurality of patterns of image forming conditions, and the density and line thickness are measured using line sensor 432 to determine the desired image forming conditions. Since toner is consumed during image stabilization processing, the amount consumed is usually kept to a minimum from the viewpoint of extending the life of toner bottle 300 and increasing the productivity of image forming apparatus 100.

[0169] Therefore, by increasing the frequency with which image stabilization processing is performed, the impact on image quality caused by increasing the toner concentration in the developing device 443 can be effectively suppressed, and the amount of toner remaining in the toner bottle can be reduced.

[0170] Also, the frequency of discarding deteriorated toner from the developing device is increased (S1117).

[0171] When the coverage of an image formed by a user of image forming apparatus 100 is low, the amount of toner supplied from developing device 443 onto the outer circumferential surface of photosensitive drum 444 during image formation is small, and the toner remains in developing device 443 for a long time. Meanwhile, inside developing device 443, the developer is circulated and transported while being agitated, which causes friction between the toner and the carrier.

[0172] Toner particles usually have external additives attached to their surfaces for the purpose of improving image quality, and have the function of, for example, preventing image defects such as white background fogging when developing an electrostatic latent image by charging the toner to a required level, just enough.

[0173] Such external additives may become embedded in the toner when the toner is subjected to friction with the carrier. When the external additives become embedded in the toner, they are unable to perform their original functions, and for example, the toner cannot be charged to the required level, which is one of the causes of image defects such as white background fogging.

[0174] In order to prevent such image defects from occurring, the discharge port 902 of the discharge section 900 of the developing device 443 is opened to discharge the developer only when it is determined that the toner has deteriorated in the developing device 443, such as when the formation of an image with low coverage continues.

[0175] In this way, it is possible to reduce the amount of deteriorated toner remaining in developing device 443, thereby suppressing image defects such as white background fogging. In addition, since the frequency of discharging developer is reduced, it is possible to prevent the life of toner bottle 300 from being shortened more than necessary as a result of developer in developer 443 being unnecessarily discarded.

[0176] On the other hand, when the replacement time for toner bottle 300 is approaching, there is no need to extend the life of toner bottle 300 beyond the replacement time. Therefore, by increasing the frequency of disposing of degraded toner, it is possible to reduce the amount of toner remaining in toner bottle 300 while improving image quality.

[0177] It should be noted that, as for the processing from steps S1114 to S1117, it is not necessary to execute all of the steps S1114 to S1117 as long as one or more of the steps S1114 to S1117 are executed.

[0178] In addition, the amount of toner remaining in toner bottle 300 may be reduced by performing processing other than the processing from steps S1114 to S1117, or such processing may be combined with one or more of the processing from steps S1114 to S1117.

[0179] Toner that may remain in toner bottle 300 when it is time to replace it may be used for purposes other than improving image quality. For example, in image forming apparatus 100, which uses a cleaning blade to clean the outer circumferential surface of photosensitive drum 444 and the outer circumferential surface of intermediate transfer belt 453, by supplying toner from developing device 443, friction between the outer circumferential surface of photosensitive drum 444 or intermediate transfer belt 453 and the cleaning blade can be reduced, thereby extending the life of the cleaning blade.

[0180] Therefore, by supplying toner from the developing device 443 corresponding to the toner color of YMCK whose toner bottle 300 is nearing the scheduled replacement time, the life of the cleaning blade that cleans the outer surface of the photosensitive drum 444 corresponding to that toner color can be extended.

[0181] It is also possible to extend the life of the cleaning blade that cleans the outer peripheral surface of the intermediate transfer belt 453. At the same time, the amount of toner remaining in the toner bottle 300 can be reduced.

[0182] After the process in step S1117 is completed, the process returns to step S1101 and the above process is repeated.

[0183] After replacing toner bottle 300, steps S1114 to S1117 are canceled. That is, the amount of toner supplied from toner bottle 300 to sub-hopper 470 is returned to the normal amount, and the toner concentration setting value of developing device 443 is also returned to the normal value.

[0184] Furthermore, the frequency with which the image stabilization process is performed is returned to the normal frequency, and the frequency with which degraded toner is discarded from the developing device 443 is also returned to the normal frequency.

[0185] In addition, since user convenience will be reduced if image forming apparatus 100 cannot be used by the scheduled replacement time, it is desirable to increase the amount of toner supplied from toner bottle 300 in steps S1114 to S1117 to the extent that the toner in toner bottle 300 is not used up earlier than the scheduled replacement time. [7] Example of operation Furthermore, an operation example will be given to explain the process executed by image forming apparatus 100 to reduce the amount of remaining toner when toner bottle 300 is replaced.

[0186] As shown in Figure 13(a), consider a case where it is estimated that there are eight days left until the toner bottle 300 runs out. If the estimation error is ±2 days, it will take a maximum of 10 days for the toner in the toner bottle 300 to run out. In the shortest case, the toner may run out in just six days.

[0187] During the period from when the toner runs out until the toner bottle 300 is replaced, the user cannot use the image forming apparatus 100. To shorten the period during which the image forming apparatus 100 cannot be used and ensure user convenience, it is necessary to replace the toner bottle 300 sooner than in the shortest case.

[0188] Naturally, the time when the toner in the toner bottle 300 is used up varies within a margin of error, so in many cases, toner will remain in the toner bottle 300 when the toner bottle 300 is replaced.

[0189] In such a case, when the maintenance service center 110 is notified that the toner bottle 300 will be consumed in eight days and that the margin of error is ±2 days, the maintenance service center 110 calculates the shortest possible time for consumption as six days and arranges for a replacement toner bottle 300 and a serviceman so that the toner bottle 300 can be replaced by this shortest possible time for consumption.

[0190] If a service technician is not dispatched, only a replacement toner bottle 300 is arranged. After making such arrangements, the maintenance service center 110 notifies the image forming apparatus 100 of the scheduled replacement time, ie, when a service technician will be dispatched or when the replacement toner bottle 300 will be delivered.

[0191] In the example shown in FIG. 13, the replacement date is scheduled for the 4th.

[0192] According to the estimation of image forming apparatus 100, the earliest possible time for toner bottle 300 to be used up is six days, so at least six days' worth of toner remains in toner bottle 300. However, the replacement schedule notified by maintenance service center 110 is four days' worth, which is two days behind the earliest possible time for toner to be used up. Therefore, at the time of the scheduled replacement, at least two days' worth of toner will remain in toner bottle 300.

[0193] Considering the estimation error of the consumption time, the longest consumption time is 10 days, which is 6 days behind the scheduled replacement time (4 days). Therefore, it is possible that a maximum of 6 days' worth of toner remains in toner bottle 300 at the scheduled replacement time.

[0194] However, when toner is supplied from toner bottle 300 assuming the maximum amount of remaining toner so that the remaining toner will be gone by the time of scheduled replacement, if the actual amount of remaining toner is less than the maximum amount of remaining toner, the toner in toner bottle 300 will be used up before the scheduled time of replacement arrives.

[0195] For example, if the toner in toner bottle 300 is depleted by increasing the frequency of image stabilization processing or the frequency of disposing of degraded toner, there may not be much toner remaining in sub-hopper 470 or developing device 443, and it may become impossible to perform image formation processing before the scheduled replacement time arrives.

[0196] This situation of reduced user convenience can occur not only when the longest consumption period is assumed, but also when a consumption period longer than the shortest consumption period is assumed, although this is less likely.

[0197] Therefore, in consideration of user convenience, it is safer to increase the amount of toner supplied from toner bottle 300 assuming the shortest possible time for consumption.

[0198] Therefore, when increasing the frequency of image stabilization processing, as in step S1116 of FIG. 11, it is desirable to perform the image stabilization processing the number of times obtained by dividing the amount of toner consumed for two days by the amount of toner consumed when the image stabilization processing is performed only once.

[0199] The toner consumption amount for two days may be estimated using, for example, the approximation line 1202 in FIG.

[0200] Furthermore, when increasing the frequency of discarding degraded toner, as in step S1117 of Figure 11, it is desirable to discard the amount of toner that will be consumed over two days. In other words, it is preferable to increase the amount of toner to be discarded to the extent that the toner is not used up earlier than the scheduled replacement time of toner bottle 300.

[0201] When steps S1116 and S1117 are used in combination, the amount of toner consumed over two days can be appropriately allocated to the image stabilization process and the disposal of degraded toner. [8] Variation The present disclosure has been described above based on the embodiments, but it goes without saying that the present disclosure is not limited to the above-described embodiments, and the following modified examples can be implemented. (8-1) In the above embodiment, the amount of remaining toner in toner bottle 300 is estimated, and the time of consumption is estimated using approximation line 1202 that least squares approximates the estimated amount of remaining toner. However, it goes without saying that the present disclosure is not limited to this, and other methods may be used instead to estimate the time of consumption.

[0202] The time to consume the toner bottle 300 can be estimated using one or more pieces of information from the image coverage, double-sided ratio, P / J, PV, temperature, humidity, and paper size. Here, image coverage means the ratio of the output image area (formed image area) to the total area (image formation area) on one side of the recording sheet.

[0203] The double-sided ratio is the ratio of double-sided printing to the total number of sheets on which images are formed. P / J (Pages / Job) is the number of pages printed per image forming job, and PV (Process Velocity) is the process speed.

[0204] The temperature and humidity are those within the image forming apparatus 100 and are detected by sensors installed within the image forming apparatus 100. The paper size is specified in the image forming job.

[0205] Regardless of the method of estimating the time of consumption, the present disclosure can reduce the amount of remaining toner at the time when the toner bottle 300 is scheduled to be replaced. (8-2) In the above embodiment, the example of extending the time for which the supply roller 513 is rotated in step S1114 of FIG. 11 has been described. However, it goes without saying that the present disclosure is not limited to this, and the following may be used instead.

[0206] For example, if the amount of toner stored in the sub-hopper 470 is increased, the accuracy of estimating the amount of toner stored in the sub-hopper 470 may decrease, or the accuracy of the amount of toner supplied from the sub-hopper 470 to the developing device 443 may decrease.

[0207] Considering such a problem, the amount of toner that can be supplied from the toner bottle 300 to the sub-hopper 470 may be divided into small portions and supplied within the period until the scheduled replacement time.

[0208] In this way, it is possible to prevent the above-mentioned problems that may occur when the amount of toner stored in the sub-hopper 470 is increased.

[0209] Similarly, in step S1115 of FIG. 11, since increasing the toner concentration in developing device 443 can cause problems such as fogging of white areas, the set value of the toner concentration of developing device 443 can be adjusted so that the amount of toner that can be supplied from toner bottle 300 is divided into small amounts within the period until the scheduled replacement date.

[0210] In this way, the above-mentioned problems that may occur when the toner concentration in the developing device 443 is increased can be suppressed.

[0211] Similarly, in step S1117 of FIG. 11, since discarding a large amount of developer from developing device 44 at once may result in a deterioration in image quality, the developer in developing device 443 may be discarded in small amounts within the period until the scheduled replacement date, so that the amount of developer that can just supply all the toner in toner bottle 300 is discarded.

[0212] In this way, it is possible to prevent problems that may occur when a large amount of developer in the developing device 443 is discarded at once. (8-3) In the above embodiment, the toner is supplied from the toner bottle 300 to the developing device 443 via the sub-hopper 470 on the way thereto. However, it goes without saying that the present disclosure is not limited to this, and the following may be used instead.

[0213] For example, in image forming apparatus 100 that does not have sub-hopper 470, the amount of toner directly supplied from toner bottle 300 to developing device 443 may be increased by increasing the toner concentration in developing device 443. This also makes it possible to reduce the amount of toner remaining in toner bottle 300 when it is time to replace it.

[0214] Even in this case, considering that increasing the toner concentration in developing device 443 can cause problems such as white background fogging, the set value of the toner concentration of developing device 443 may be adjusted so that the amount of toner in toner bottle 300 that can be supplied in small amounts within the period until the scheduled replacement date.

[0215] In this way, problems such as fogging on white background that may occur when the toner concentration in the developing device 443 is increased can be suppressed. (8-4) In the above embodiment, an example was described in which the consumption time is estimated using an approximation line 1202 that performs a least-squares approximation of the estimated value of the residual toner amount, and the consumption time and its error range are notified to the maintenance service center 110. However, it goes without saying that the present disclosure is not limited to this, and the following may be used instead.

[0216] For example, instead of notifying the time of consumption and the error range, only the time at the lower limit of the error range may be notified to the maintenance service center 110 as the replacement deadline for the toner bottle 300. Even in this way, the maintenance service center 110 can be made to determine and notify the scheduled replacement time.

[0217] Furthermore, image forming apparatus 100 may notify maintenance service center 110 only of the consumption time without notifying the error range. If the variation in the error range according to the usage status of image forming apparatus 100 by the user is small (for example, less than one day), maintenance service center 100 may uniformly apply a common error range to all image forming apparatuses 100 to determine the scheduled replacement time for toner bottle 300.

[0218] In addition, if the maintenance service center 100 has already received and stored notification of the error range from the image forming device 100 and is able to use the stored error range, the maintenance service center 100 may appropriately determine the scheduled replacement time for the toner bottle 300 without receiving notification of the error range.

[0219] Even in this case, the same effect can be obtained by applying the present disclosure. (8-5) In the above embodiment, an example was given of a case where processing such as increasing the amount of toner supplied from the toner bottle 300 to the sub-hopper 470 (S1114 to S1117 in Figure 11) is performed when the scheduled replacement time for the toner bottle 300 is notified. However, instead of or in addition to this, the following may be performed.

[0220] For example, when replacing toner bottle 300, prior to removing toner bottle 300 from image forming apparatus 100, the toner in toner bottle 300 may be supplied to sub-hopper 470 to the extent that it can be stored in sub-hopper 470.

[0221] In addition, in an image forming apparatus 100 that does not have a sub-hopper 470, when replacing the toner bottle 300, the toner in the toner bottle 300 may be supplied to the developing device 443 to the extent that it can be stored in the developing device 443 before removing the toner bottle 300 from the image forming apparatus 100.

[0222] In this way, when replacing toner bottle 300, if there is room to store toner in sub-hopper 470 or developing device 443, the amount of toner remaining in toner bottle 300 can be further reduced beyond the amount of toner that can be consumed by the time of replacement. (8-6) In the above embodiment, an example was described in which the image forming apparatus 100 notifies the maintenance service center 110 of the time when the toner bottle 300 is consumed and the error range thereof. However, it goes without saying that the present disclosure is not limited to this, and instead, the following may be adopted.

[0223] For example, the time when the toner bottle 300 will be consumed and its error range, or the replacement deadline as described above, may be displayed on the operation panel 340 of the image forming device 100 to prompt the user of the image forming device 100 to request a toner bottle 300 replacement service or to purchase a toner bottle 300.

[0224] As a result, when the user of the image forming device 100 obtains the planned replacement time for the toner bottle 300, instead of the image forming device 100 receiving notification of the planned replacement time for the toner bottle 300 from the maintenance service center 110, the user of the image forming device 100 may input the planned replacement time for the toner bottle 300 using the operation panel 340.

[0225] In such cases, the same effect can be obtained by applying the present disclosure. (8-7) In the above embodiment, an example was given in which, if it is determined in step S1113 of FIG. 11 that the planned replacement time is earlier than the consumption time, measures (S1114 to S1117) are always taken to reduce the amount of toner remaining in toner bottle 300 when toner bottle 300 is replaced. However, it goes without saying that the present disclosure is not limited to this, and instead, the following may be taken.

[0226] For example, in step S1113 of FIG. 11, if it is determined that the planned replacement time is earlier than the time of consumption, the user may be asked whether to take measures (S1114 to S1117) to reduce the amount of toner remaining in toner bottle 300 when replacing toner bottle 300.

[0227] This inquiry may be made, for example, by displaying a message on the operation panel 340 and outputting an alarm sound in conjunction with the message display. Also, the operation panel 340 may be used to receive a user's instruction input as to whether or not to execute the measure.

[0228] Measures such as increasing the frequency of image stabilization processing may affect the productivity of image forming device 100, whereas the above-described method allows image forming device 100 to perform appropriate operations according to the individual circumstances of each user, thereby ensuring user convenience. (8-8) In the above embodiment, the image forming apparatus 100 is described as a tandem color multifunction printer. However, the present disclosure is not limited to this, and the image forming apparatus 100 may be a color multifunction printer other than a tandem type, or may be a monochrome multifunction printer.

[0229] Furthermore, the image forming apparatus 100 may be a single-function machine such as a printer, a copy machine with a scanning function, or a facsimile machine with a facsimile communication function. In any case, the same effects can be obtained by applying the present disclosure. [Industrial Applicability]

[0230] The image forming apparatus according to the present disclosure is useful as an apparatus that can reduce the amount of toner that is wasted by reducing the amount of toner remaining in the toner bottle when the toner bottle is replaced. [Explanation of symbols]

[0231] 1. Maintenance service system 100...Image forming apparatus 110...Maintenance Service Center 120...Communication Network 300...Toner bottle 310...Image reading unit 320...Image forming unit 321...Control unit 330…Paper feed section 340...Operation panel 410...Cleaning device (for intermediate transfer belt 453) 431...Toner density sensor 443...Developing device 444...Photosensitive drum 447...Cleaning device (for photosensitive drum 444) 470...Subhopper 471…Supply pipe 502...Bottle section 503...Cap part 503a...Toner supply port 505...Shutter section 511...Stirring plate 511a...Stirring shaft 512…Cam 513...supply roller 514...Float member 514a...oscillating shaft of float member 514 514b...Floating body 514c...Magnet 515...Empty sensor 521...Drive source 521a...connection mechanism of drive source 512 531...Agitation conveying screw 532...Supply screw 533...Developing roller 900…Discharge section 901...Reverse winding screw 902...Exhaust port 911...Agitation and transport layer 912…Supply tank 1011...Printer controller 1012...Engine control unit

Claims

1. An electrophotographic image forming apparatus having a detachable toner bottle and a predicting means for predicting when the toner stored in the toner bottle will be used up when the toner bottle is attached, An acquisition means for acquiring a planned replacement time for the toner bottle; an increasing means for increasing the amount of toner supplied from the toner bottle so that the toner is used up earlier than the toner bottle's consumption time, if the scheduled replacement time of the toner bottle precedes the toner bottle's consumption time; a developing means for developing an electrostatic latent image when forming an image by an electrophotographic method; a sub-hopper for temporarily storing the toner supplied from the toner bottle and supplying the toner to the developing means; a sensor that detects when the toner level in the sub-hopper has dropped to a predetermined level; Equipped with the increasing means increases the amount of toner supplied from the toner bottle to the sub-hopper and increases the amount of toner supplied from the sub-hopper to the developing means, The prediction unit makes the prediction in response to the detection by the sensor, and thereafter, the increase unit increases the toner amount. An image forming apparatus characterized by:

2. a receiving means for receiving an instruction as to whether or not to increase the amount of toner supplied from the toner bottle; and a prohibiting means for prohibiting the increasing means from increasing the toner amount when the accepting means accepts a negative instruction.

2. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

3. The increasing means increases the amount of toner supplied from the toner bottle to the sub-hopper from a normal amount after the toner bottle is replaced.

3. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

4. A first control means for supplying toner from the sub-hopper to the developing means so that the toner concentration in the developing means becomes a target concentration; The increasing means increases the target concentration in the first control means.

4. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

5. The increasing means increases the operation of consuming the toner more than when the toner consumption time is predicted.

3. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

6. image stabilization means for executing image stabilization processing to stabilize the quality of the image to be formed; The increasing means increases the frequency with which the image stabilization means executes the image stabilization process.

6. The image forming apparatus according to claim 5,

7. The developing means has a discharge means for discharging deteriorated toner, The increasing means increases the amount of deteriorated toner discharged by the discharging means.

7. The image forming apparatus according to claim 5, wherein the image forming apparatus is a recording medium.

8. The increasing means increases the amount of toner within a range in which the toner is not used up earlier than the scheduled replacement time.

8. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

9. The prediction means predicts the consumption time using one or more of image coverage, double-sided ratio, P / J, PV, temperature, humidity, and paper size.

9. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

10. The acquisition means a notification means for notifying the source of the replacement schedule of the consumption time, The planned replacement time is determined by the supplier in accordance with the consumption time.

10. The image forming apparatus according to claim 1, wherein the image forming apparatus comprises: a first fixing member;

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