Image forming device

Abstract

To provide a configuration that can adjust an amount of developer discharged from a developer supply container in one supply operation.SOLUTION: A toner cartridge has a toner storage unit 12 that can store toner, a discharge port 15a that discharges toner, a pump unit 16, and a reciprocating link mechanism that converts driving force input from a driving motor into a direction to expand and contract the pump unit. The pump unit 16 is expanded and contracted to perform exhaust operation to exhaust air from the inside to the outside of the toner cartridge through the exhaust port 15a and intake operation to take in air from the outside to the inside of the toner cartridge through the exhaust port 15a. The pump unit can discharge the toner from the inside of the toner cartridge together with the air in association with the exhaust operation. A CPU can vary an interval from the exhaust operation to next intake operation.SELECTED DRAWING: Figure 9

Description

[Technical Field]

[0001] The present invention relates to an image forming apparatus such as a copier, printer, facsimile, or a multifunction machine having multiple functions of these. [Background technology]

[0002] A conventional image forming apparatus is known in which developer consumed during image formation is replenished from a developer supply container. As such a developer supply container, a configuration has been proposed in which developer is replenished by extending and contracting a pump portion (Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-186138 Summary of the Invention [Problem to be solved by the invention]

[0004] However, if the type of developer used in the image forming apparatus is changed and the physical properties (fluidity and density) of the developer are changed, there is a risk that the amount of developer replenished in one replenishment operation, i.e., the amount discharged from the developer replenishment container, will change. Also, even if the amount of developer replenished in one replenishment operation does not change, the amount of developer required in one replenishment operation may change as the image formation mode executed in the image forming apparatus is changed.

[0005] An object of the present invention is to provide a configuration that makes it possible to adjust the amount of developer discharged from a developer supply container in one supply operation. [Means for solving the problem]

[0006] an image forming apparatus according to the present invention, comprising: a developer supply container detachable from an image forming apparatus main body; a drive unit that drives the developer supply container attached to the image forming apparatus main body; and a control unit that controls the drive unit; wherein the developer supply container has a developer storage section that can store developer; an outlet that discharges the developer stored in the developer storage section from the developer supply container; a pump section that expands and contracts to perform an exhaust operation that discharges air from the inside of the developer supply container to the outside through the outlet and an intake operation that sucks air from the outside of the developer supply container to the inside through the outlet, and is capable of discharging the developer together with the air from inside the developer supply container as a result of the exhaust operation; and a drive conversion section that converts a drive force input from the drive unit in a direction that expands and contracts the pump section, The control unit is capable of executing a first mode and a second mode in which the image forming speed is slower than that of the first mode, and the second mode has a shorter interval from the exhaust operation to the next intake operation than the first mode. It is characterized by: [Effects of the Invention]

[0007] According to the present invention, it is possible to adjust the amount of developer discharged from the developer supply container in one supply operation. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a cross-sectional view showing a schematic configuration of an image forming apparatus according to a first embodiment. [Figure 2] 1A is a perspective view of a toner supply device according to a first embodiment, and FIG. 1B is a perspective view showing a state in which a toner cartridge is attached and detached to the toner supply device according to the first embodiment. [Figure 3] FIG. 2A is a perspective view of a toner cartridge drive device according to a first embodiment, and FIG. 2B is a perspective view of a drive transmission unit extracted from the toner cartridge drive device. [Figure 4] FIG. 2 is a perspective view showing a state in which the toner cartridge according to the first embodiment is mounted in a toner cartridge drive device. [Figure 5] FIG. 2 is a block diagram showing a control configuration for a toner supply device according to the first embodiment. [Figure 6] 1A is a perspective view of a toner cartridge according to a first embodiment, and FIG. 1B is a cross-sectional perspective view thereof. [Figure 7]FIG. 2 is a perspective view showing a part of a toner discharge portion according to the first embodiment in a cutaway view. [Figure 8] 3A and 3B are plan views of the toner discharge portion according to the first embodiment, seen from above with a portion cut away, showing the pump in a contracted state and the pump in an extended state. [Figure 9] Schematic diagrams showing the suction and exhaust operation of the pump section in the first embodiment, in which (a) the pump section is in an extended state, (b) the state immediately after the pump section has contracted from the state in (a), (c) the state after toner has been discharged from the state in (b), and (d) the state after the pump section has expanded from the state in (c). [Figure 10] (a) Graph showing the relationship between the amount of toner discharged and time from when the pump section is compressed and the internal pressure becomes positive until it reaches equilibrium with atmospheric pressure, and (b) Graph showing the relationship between the amount of toner discharged and time when the pump section is expanded before the toner discharge caused by compressing the pump section is completed. [Figure 11] 10 is a graph showing the relationship between the rotation speed of the toner cartridge and the amount of toner discharged in one expansion / contraction operation of the pump section. [Figure 12] 10 is a flowchart showing the flow of control for selecting an image forming mode and setting the speed of a drive motor according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] First Embodiment The first embodiment will be described with reference to Figures 1 to 11. First, the schematic configuration of an image forming apparatus according to this embodiment will be described with reference to Figure 1.

[0010] [Image forming equipment] The image forming apparatus 60 of this embodiment is an electrophotographic color printer. Because of its advantages of adaptability to a wide variety of sheet materials and excellent print productivity, it employs an intermediate transfer tandem system in which four color image forming units are arranged side by side on an intermediate transfer belt 61. In this embodiment, an image is formed using four colors: yellow (Y), magenta (M), cyan (C), and black (K). Of course, the number of colors is not limited to four, and the order of the colors is not limited to this. The image forming process for forming an image on a sheet serving as a recording material in the image forming apparatus of this embodiment is described below. The recording material may be, for example, a sheet material such as paper or a plastic sheet. The developer used in this embodiment is a two-component developer containing non-magnetic toner and a magnetic carrier, but a single-component developer containing toner but no carrier may also be used.

[0011] The sheets S are stored in a stacked manner in a sheet storage section 62, and are fed by a feed roller 63 in accordance with the image formation timing. The sheets S sent out by the feed roller 63 pass through a conveying path 64 and are conveyed to a registration roller 65. The registration roller 65 corrects the skew of the sheets S conveyed from the sheet storage section 62, and then conveys the sheets S to a secondary transfer section at a predetermined timing in accordance with the toner image formed on the intermediate transfer belt 61.

[0012] The secondary transfer portion is a nip portion where a toner image is transferred to the sheet S, which is formed by the portion of the intermediate transfer belt 61 stretched by the inner secondary transfer roller 66 and the outer secondary transfer roller 67. In the secondary transfer portion, a predetermined pressure force and an electrostatic load bias are applied to transfer the toner image formed on the intermediate transfer belt 61 onto the sheet S. The image formation process for forming a toner image on the intermediate transfer belt 61 will be described next.

[0013] Image forming unit 600 is mainly composed of a photosensitive drum (photoconductor) 1 as an image carrier, a charging roller 2 as a charging means, a developing device 3, a primary transfer roller 4 as a primary transfer means, and a drum cleaner 5. Similar components are arranged in parallel for four colors: yellow (Y), magenta (M), cyan (C), and black (K). A toner supply device 605 as a developer supply device is arranged above image forming unit 600, and toner cartridges 10Y, 10M, 10C, and 10K are provided as developer supply containers capable of containing toner (developer) corresponding to the image forming units of each color. The toner supply device 605 will be described in detail below.

[0014] In the image formation process, first, the photosensitive drum 1, whose surface has been uniformly charged in advance by the charging roller 2, is irradiated with exposure light by the exposure device 68 based on image information signals sent from a document reading device or external equipment, and an electrostatic latent image is formed on the surface of the photosensitive drum 1. Next, the electrostatic latent image formed on the photosensitive drum 1 is developed with toner by the developing device 3, and becomes visible as a toner image on the photosensitive drum 1. The developing device 3 includes a developing container that contains developer, a transport screw that transports the developer in the developing container, and a developing sleeve that carries and transports the developer in the developing container and develops the electrostatic latent image on the photosensitive drum 1.

[0015] After a toner image is formed on the photosensitive drum 1, a predetermined pressure and electrostatic load bias are applied to the photosensitive drum 1 via the intermediate transfer belt 61 by the primary transfer roller 4, and the toner image is transferred from the photosensitive drum 1 to the intermediate transfer belt 61. Any residual toner remaining on the photosensitive drum 1 after transfer is collected by the drum cleaner 5. The toner consumed by the developing device 3 is supplied from the toner cartridges 10Y, 10M, 10C, and 10K to prepare for the next image formation. The developer contained in the toner cartridges may contain toner and carrier, or may contain toner but not carrier. For example, if the developing device 3 is configured to automatically discharge carrier, the toner cartridges 10Y, 10M, 10C, and 10K contain a developer containing toner and carrier.

[0016] The intermediate transfer belt 61 is stretched by rollers such as driven rollers 7a and 7b, a tension roller 6, and a secondary transfer inner roller 66, and is driven to be transported in the direction of arrow X in Fig. 1. The image formation processes for each color, which are processed in parallel by the image forming units 600 for Y, M, C, and K, are performed at timings such that the image is superimposed on the toner image of the upstream color that has been primarily transferred onto the intermediate transfer belt 61. As a result, a full-color toner image is finally formed on the intermediate transfer belt 61 and is transported to the secondary transfer unit.

[0017] Through the above process, a full-color toner image is secondarily transferred onto the sheet S at the secondary transfer unit. The sheet S is then conveyed to the fixing unit 9. The fixing unit 9 applies a predetermined pressure from opposing rollers or belts, and heat, typically from a heat source such as a heater, to melt and fix the toner image on the sheet S. After being fixed by the fixing unit 9, the sheet S is discharged to a discharge tray 601 by discharge rollers 69, completing the image formation process. When an image is to be formed on both sides of the sheet S, the sheet S with an image formed on one side thereof is conveyed in a switchback direction by the discharge rollers 69 after passing through the fixing unit 9. At this time, the position of the switching member 602 is switched, and the sheet S conveyed in a switchback direction is guided to a double-sided conveying path 603. The sheet S is conveyed to the registration rollers 65 through the double-sided conveying path 603. Then, an image is formed on the back side of the sheet S in the same manner as described above.

[0018] [Toner supply device] 2(a) to 4, a toner supply device 605 serving as a developer supply device will be described. First, as shown in Figures 2(a) and 2(b), the toner supply device 605 is composed of toner cartridges 10Y, 10M, 10C, and 10K serving as developer supply containers detachably attachable to the image forming apparatus main body 60a (Figure 1), a toner cartridge tray 610, a toner cartridge drive device 611, and an inner cover 620. The toner cartridge tray 610, the toner cartridge drive device 611, and the inner cover 620 are disposed inside the image forming apparatus main body 60a.

[0019] The toner cartridge tray 610 has a guide function when the toner cartridges 10Y, 10M, 10C, and 10K are mounted in the image forming apparatus main body 60a, and a function to hold the toner cartridges 10Y, 10M, 10C, and 10K when mounted.

[0020] The toner cartridge drive device 611 has a function of rotating the toner storage units 12 (see FIG. 4, etc.) of the toner cartridges 10Y, 10M, 10C, and 10K. By rotating, the toner storage units 12 of the toner cartridges 10Y, 10M, 10C, and 10K have a function of transporting and supplying (replenishing) the toner in the toner cartridges 10Y, 10M, 10C, and 10K to the corresponding developing devices 3.

[0021] The inner cover 620 is provided with an attachment / detachment opening 621 corresponding to the toner cartridges 10Y, 10M, 10C, and 10K of each color. As shown in FIG. 2(b), the toner cartridges 10Y, 10M, 10C, and 10K are attached and detached through the attachment / detachment opening 621 in the direction of arrow A. Note that FIG. 2(b) shows the case where the magenta toner cartridge 10M is being attached and detached, and the same configuration is used for toner cartridges of other colors.

[0022] Next, the toner cartridge drive device 611 will be described in detail using Figures 3(a) to 4. Figure 3(a) is a perspective view of the toner cartridge drive device 611, and Figure 3(b) is a parts diagram extracting only the drive transmission section of the toner cartridge drive device 611. The toner cartridge drive device 611 is made up of a drive base 650, a drive motor 652 as a drive section, a pinion gear 655, a reduction gear 656, a transmission gear 657, a drive shaft 654, a drive gear 651, a drive cover 653, a toner cartridge rotation phase detection sensor 640, etc.

[0023] Drive motor 652 is fixed to drive base 650, and pinion gear 655 is press-fitted onto the motor shaft of drive motor 652. Reduction gear 656 is rotatably held by drive base 650 and drive cover 653, and is disposed in a positional relationship where the gear teeth of pinion gear 655 and transmission gear 657 mesh with each other. Drive shaft 654 is rotatably held by drive base 650, and transmission gear 657 is fixed to one end of drive shaft 654, and drive gear 651 is fixed to the other end. As described above, the rotational drive of drive motor 652 is transmitted to drive gear 651 via pinion gear 655, reduction gear 656, transmission gear 657, and drive shaft 654.

[0024] The toner cartridge rotation phase detection sensor 640 is a sensor that detects the home position of the rotation phase of the toner storage section 12 of the toner cartridges 10Y, 10M, 10C, and 10K when the toner storage section 12 of the toner cartridges 10Y, 10M, 10C, and 10K is rotated while the toner cartridges 10Y, 10M, 10C, and 10K are attached to the toner cartridge tray 610.

[0025] 4 is a diagram showing the operation when the toner cartridge 10Y (10M, 10C, 10K) is rotationally driven by the toner cartridge drive device 611. As shown in FIG. 4, when the toner cartridge 10Y (10M, 10C, 10K) is installed in the device, the cartridge gear 11 as a drive input portion provided in the toner cartridge 10Y (10M, 10C, 10K) and a drive gear 651 are disposed in a positional relationship in which the gear teeth mesh with each other. As a result, the rotation of the drive gear 651 rotates the toner storage portion 12 of the toner cartridge 10Y (10M, 10C, 10K).

[0026] [Control configuration for controlling the operation of the toner supply device] 5 is a block diagram showing a control configuration 40 that controls the operation of the toner supply device. The control configuration 40 is composed of a CPU 400, a system controller 410, a display panel 73, a toner supply control unit 421, a developing device control unit 422, an environment sensor 430, and the like. The CPU 400 as a control unit has a ROM 401, a RAM 402, and an EEPROM 403. The ROM 401 stores a control program for controlling the entire image forming apparatus 60. The RAM 402 is a volatile storage device that is used as a work area for the CPU 400 and also for temporarily storing various data such as image data. The EEPROM 403 is a non-volatile storage device that stores various data such as the toner concentration in the developing device 3.

[0027] The CPU 400 controls the entire image forming apparatus 60 by loading a control program stored in the ROM 401 into the RAM 402 and executing it. The toner supply control unit includes a drive motor 652 and a toner cartridge rotation phase detection sensor 640. The developing device control unit 422 includes a motor that drives the developing sleeve and conveying screw of the developing device 3 and a sensor that detects the toner concentration in the developing device. The environment sensor 430 can detect the temperature and humidity inside the image forming apparatus main body 60a, and the CPU 400 can calculate the relative humidity based on a signal input from the environment sensor 430. The CPU 400 is electrically connected to the drive systems of the toner supply control unit 421 and the developing device control unit 422 via control blocks and various drivers (not shown). This allows the CPU 400 to control the rotational speed of the toner cartridges 10Y, 10M, 10C, and 10K, control the developing device 3, and so on.

[0028] [Toner cartridge (developer supply container)] Next, the configuration of toner cartridges 10Y, 10M, 10C, and 10K as developer supply containers will be described with reference to Figures 6(a) to 8(b). In the following, toner cartridge 10Y will be described as a representative, but toner cartridges 10M, 10C, and 10K also have a similar configuration.

[0029] Fig. 6(a) is a perspective view of the entire toner cartridge 10Y, and Fig. 6(b) is a cross-sectional perspective view of the entire toner cartridge 10Y. The toner cartridge 10Y is composed of a cartridge gear 11, a toner storage section 12, a toner transport member 13, and a toner discharge section 14. The toner storage section 12, which serves as a developer storage section, has a hollow, approximately cylindrical shape and stores toner therein. A spiral-shaped transport protrusion 12a that protrudes toward the interior of the toner storage section 12 is formed on the inner circumferential surface of the toner storage section 12, and as the toner storage section 12 rotates, the toner stored therein is transported toward the toner discharge section 14 by the transport protrusion 12a.

[0030] The toner transport member 13 is disposed at a position spanning both the toner storage unit 12 and the toner discharge unit 14 and is fixed to the toner storage unit 12. The toner transport member 13 rotates integrally with the toner storage unit 12 as the toner storage unit 12 rotates. The toner transport member 13 is capable of transporting toner using the inclined surface formed thereon and has the function of transferring toner transported by the transport protrusions 12a to the toner discharge unit 14. The cartridge gear 11 is fixed to the toner storage unit 12 at a position coaxial with the cylindrical shape of the toner storage unit 12. The toner discharge unit 14 has an outlet 15a through which toner contained in the toner storage unit 12 is discharged from the toner cartridge 10Y to the outside, and is held at a longitudinal end of the toner storage unit 12 in a state that allows relative rotation with the toner storage unit 12. As a result, the toner storage unit 12 rotates when the driving force of the drive motor 652 is input to the cartridge gear 11 via the drive gear 651, and transports the toner contained therein toward the outlet 15a.

[0031] Next, the toner discharge unit 14 will be described in detail using Figures 7, 8(a), and 8(b). Figure 7 is a detailed explanatory diagram of the toner discharge unit 14. For ease of explanation, this diagram shows only the cross section of the cover 18, which is a component of the toner discharge unit 14, so that the interior of the toner discharge unit 14 can be seen. Figures 8(a) and 8(b) are explanatory diagrams of the operation of the toner discharge unit 14. The toner discharge unit 14 is made up of a toner discharge unit base 15, a pump unit 16, a reciprocating link mechanism 17, and a cover 18.

[0032] Toner storage unit 12 is rotatably held at one end of toner discharge unit base 15, and an opening is provided in each of the mating surfaces thereof, allowing the internal spaces of toner discharge unit base 15 and toner storage unit 12 to communicate with each other. Pump unit 16 is fixed to the other end of toner discharge unit base 15, and similarly, an opening is provided in the mating surface thereof so that the internal spaces of toner discharge unit base 15 and pump unit 16 communicate with each other. Discharge port 15a is formed in the underside of toner discharge unit base 15, connecting the external space with the internal space of toner discharge unit base 15, and toner in toner discharge unit 14 is discharged to the outside through discharge port 15a. The opening area of ​​discharge port 15a is set small enough so that toner inside is not discharged to the outside by gravity alone.

[0033] Pump section 16 employs a variable-volume resin bellows-shaped pump, and the volume inside pump section 16 can be varied by displacing the opposite end in the expansion / contraction direction while keeping one end fixed. That is, by expanding and contracting, pump section 16 performs an exhaust operation that exhausts air from the inside of the toner cartridge to the outside through outlet 15a, and an intake operation that sucks air from the outside of the toner cartridge into the inside through outlet 15a. The exhaust operation can then discharge toner together with air from the toner cartridge (developer supply container).

[0034] The reciprocating link mechanism 17 serving as the drive conversion unit has a cam groove 11a formed on the outer peripheral surface of the toner storage unit 12, and a link member 17b having one end fixed to the pump unit 16 and the other end provided with a protrusion 17a serving as an engaging unit that engages with the cam groove. The link member 17b is held by the cover 18 so as to be able to reciprocate in the direction of arrow B in FIG. 7 (the direction of the rotation axis of the toner storage unit 12), and one end is fixed to the end of the pump unit 16 that is not fixed to the toner discharge unit base 15. Furthermore, as shown in FIGS. 8(a) and 8(b), the other end of the link member 17b has a protrusion 17a formed thereon, which engages with the cam groove 11a formed in the toner storage unit 12.

[0035] The cover 18 is shaped to cover the entire surface of the toner discharge section 14 except for the surface on which the discharge outlet 15a is formed and the surface joined to the toner storage section 12, and is fixed to the toner discharge section base 15.

[0036] In this embodiment, with this configuration, when the toner storage unit 12 rotates, the link member 17b moves along the cam groove 11a, expanding and contracting the pump unit 16. In other words, the rotational movement of the toner storage unit 12 and the expansion and contraction movement of the pump unit 16 can be linked. Explaining the operation of each part in detail, first, when the toner storage unit 12 rotates due to the input of driving force to the cartridge gear 11, the cam groove 11a also moves in the rotational direction. The cam groove 11a is formed of a straight groove portion 11a1 whose position in the rotational axis direction does not change, and a V-shaped groove portion 11a2 whose position in the rotational axis direction does change.

[0037] When the V-shaped groove portion 11a2 passes the position of the protrusion 17a of the link member 17b, the link member 17b reciprocates along the V-shaped groove portion 11a2 in the direction of arrow B (= the direction of the rotation axis of the toner storage unit 12). On the other hand, when the straight groove portion 11a1 passes the position of the protrusion 17a, even if the toner storage unit 12 rotates, the link member 17b does not move in the direction of arrow B and remains stationary. Note that FIG. 8(a) shows the position where the straight groove portion 11a1 is engaged with the protrusion 17a, and FIG. 8(b) shows the position where the V-shaped groove portion 11a2 is engaged with the protrusion 17a.

[0038] Because pump section 16 and link member 17b are fixed, the fixed portion of pump section 16 and link member 17b also displaces in the same direction as link member 17b reciprocates, causing pump section 16 to expand and contract to vary the internal volume.

[0039] [Mechanism of toner being discharged from the toner cartridge] Next, we will explain how toner is discharged from inside toner cartridge 10Y to the outside. The same applies to toner cartridges 10M, 10C, and 10K. When toner cartridge 10Y shown in FIG. 4 is attached to toner supply device 605, toner discharge portion 14 is held by toner cartridge drive device 611 and fixed within the device. On the other hand, toner storage portion 12 is rotatably supported by toner cartridge tray 610. That is, when toner cartridge 10Y is attached to toner supply device 605 and drive force is applied by drive gear 651, relative rotation occurs between toner discharge portion 14 and toner storage portion 12.

[0040] As the toner storage unit 12 rotates, the toner inside the toner storage unit 12 is transferred to the toner discharge unit 14 by the transport protrusions 12a and the toner transport member 13. As described above, in the toner discharge unit 14, the pump unit 16 expands and contracts in response to the rotation of the toner storage unit 12. Because the interior of the toner cartridge 10Y is substantially sealed except for the outlet 15a, the pump unit 16 expands and contracts to and from the external space through the outlet 15a. Therefore, if the pump unit 16 expands and contracts while there is toner in the toner discharge unit 14, the toner inside the toner discharge unit 14 is discharged together with air from the outlet 15a. This mechanism allows the toner inside the toner cartridge 10 to be discharged to the outside by the rotational drive input.

[0041] [Suction and exhaust by the pump section and toner discharge in one process] Next, using Figures 9(a) to 11, we will explain the relationship between the suction and exhaust operation by the pump unit 16 and the amount of toner discharged per pump (one suction and exhaust operation, i.e., one expansion and contraction operation of the pump unit 16), and toner discharge control utilizing this characteristic. Figures 9(a) to 9(d) are conceptual diagrams for explaining the relationship between the suction and exhaust state of the pump unit 16 and the amount of toner discharged. Figures 10(a) and 10(b) are graphs showing the relationship between the amount of toner discharged per pump and the discharge time. Figure 11 is a diagram showing the relationship between the rotational speed (rotational speed rpm) of the toner cartridge 10 and the discharge amount per pump (g / p).

[0042] FIG. 9(a) shows the state when the atmospheric pressure outside the toner cartridge 10Y and the internal pressure inside the toner cartridge 10Y are in equilibrium. At this time, the pump unit 16 is in an expanded state. Because the opening area of ​​the discharge port 15a is set small enough as described above, toner is not discharged even if there is toner above the discharge port 15a. FIG. 9(b) shows the state immediately after the pump unit 16 is compressed from the state shown in FIG. 9(a). When the pump unit 16 is compressed, air V1 corresponding to the change in volume of the pump unit 16 moves toward the toner discharge unit base 15 and the toner storage unit 12. This causes the internal pressure of the toner cartridge 10Y to become positive relative to atmospheric pressure, and toner is discharged from the discharge port 15a along with the air. At this time, the speed at which the toner is discharged from the discharge port 15a is slower than the time it takes for the pump unit 16 to expand or contract. This is due to the small opening area of ​​the discharge port 15a and the greater resistance of the toner than the air.

[0043] 10(a) is a graph showing the relationship between the amount of toner discharged from discharge port 15a and time when toner is discharged from discharge port 15a until the internal pressure of toner cartridge 10 becomes positive due to compression of pump portion 16 and reaches equilibrium with the external atmospheric pressure. As mentioned above, the discharge speed of toner from discharge port 15a is slower than the time it takes to expand and contract pump portion 16, so toner discharge time T2 is longer than time T1 for compressing pump portion 16.

[0044] 9(c) shows the state in which, after the state in FIG. 9(b), pump unit 16 is expanded before the toner being discharged from discharge port 15a is completely discharged (before toner discharge time T2 in FIG. 10(a)). At this time, toner of an amount V2 (less than V1) has been discharged to the outside, and the remaining air of V1-V2 is taken in from the outside through discharge port 15a. Then, as shown in FIG. 9(d), pump unit 16 is in the expanded state, and the external atmospheric pressure and the internal pressure of toner cartridge 10Y return to equilibrium, resulting in a state in which V2 of toner has been discharged to the outside.

[0045] FIG. 10(b) is a diagram showing the relationship between the amount of toner discharged from the discharge port 15a and time when the pump unit 16 is extended before the toner discharged from the discharge port 15a shown in FIG. 9(c) finishes discharging. As described above, before the toner discharge due to compressing the pump unit 16 finishes, by extending the pump unit 16, the toner discharge time is shortened (T2'<T2), and the amount of toner discharged can be made smaller than when the pump unit 16 is not extended. Here, if the time from compressing the pump unit 16 to extending it is defined as the adjustment time T3, it becomes possible to adjust the toner discharge amount by adjusting the time of the adjustment time T3 within the range of the toner discharge time T2 by only compression.

[0046] In the present embodiment, since the pump unit 16 is expanded and contracted by the rotation of the toner storage unit 12, as the rotation of the toner storage unit 12 becomes faster, the time (adjustment time T3) from compression to extension of the pump unit 16 becomes shorter. That is, in the case of the present embodiment, the CPU 400 makes variable the interval (adjustment time T3) from the exhaust operation to the next intake operation of the pump unit 16. In particular, in the present embodiment, the rotation speed of the toner storage unit 12 is changed by changing the rotation speed of the drive motor 652 that rotationally drives the toner storage unit 12, and the time (adjustment time T3) from compression to extension of the pump unit 16 is changed.

[0047] Specifically, as shown in FIG. 11, the relationship between the rotation speed (rotation speed rpm) of the toner storage unit 12 and the discharge amount per pump (g / p) is such that the discharge amount per pump decreases as the rotation speed increases. Therefore, by controlling the rotation speed of the toner storage unit 12, it becomes possible to adjust the replenishment amount per pump.

[0048] In the present embodiment, the adjustment time T3 is adjusted by adjusting the rotation speed of the toner storage unit 12. However, a stepping motor or the like may be used as the drive source and intermittent driving (the drive is stopped during the time of the adjustment time T3) may be performed for adjustment. That is, the interval from the exhaust operation to the next intake operation of the pump unit 16 may be changed by changing the stop time of the stepping motor from the exhaust operation to the next intake operation.

[0049] As described above, in the present embodiment, it is possible to adjust the amount of toner (developer amount) discharged from the toner cartridges 10Y, 10M, 10C, and 10K in one replenishment operation (unit replenishment operation, one pump). For example, when the type of toner used in the image forming apparatus changes, and it is necessary to adjust the discharged amount of toner in one replenishment operation, it is possible to adjust the discharged amount of toner only by controlling the rotation speed and stop time of the motor without changing parts. That is, in order to match the required replenishment amount (toner discharge amount) and the supplied replenishment amount, it is conceivable to change the constituent parts of the toner supply device according to the required replenishment amount. However, adjusting the discharged amount of toner by changing the constituent parts of the toner supply device is troublesome and costly. In contrast, in the present embodiment, from the relationship between the suction and exhaust by the pump unit 16 and the toner discharge amount in one step, it is possible to adjust the toner discharge amount according to the required replenishment amount by controlling the rotation of the toner storage unit 12.

[0050] For example, when the type of toner used is changed from toner A to toner B, and assuming that toner B has higher fluidity than toner A, in the same configuration and the same control, the discharged amount of toner per pump is larger for toner B. Specifically explaining with reference to FIG. 11, when the rotation speed of the toner storage unit 12 of the toner cartridge 10Y is V1, the discharged amount per pump of toner A is P1, and the discharged amount per pump of toner B is P2, and the relationship between the amounts is P1 < P2. Here, even when using toner B, when P1 is required as the discharged amount per pump, by setting the rotation speed of the toner storage unit 12 of the toner cartridge 10Y to V2 (>V1), it is possible to adjust the discharged amount per pump without changing parts.

[0051] The type of toner is selected, for example, by a user through the display panel 73, and the CPU 400 controls the rotation of the toner storage unit 12 as described above in accordance with the selected type of toner. Controlling the rotation of the toner storage unit 12 to change the discharge amount per pump in this manner may be performed as appropriate when the specifications of the image forming apparatus are changed, for example, when the control program for the image forming apparatus is updated.

[0052] Furthermore, changes in the environment in which the image forming apparatus is placed may affect the fluidity of the toner in the toner cartridge. For example, a decrease in relative humidity increases triboelectricity and decreases bulk density, resulting in decreased toner fluidity. Therefore, in the image forming apparatus of this embodiment, the rotation of the toner accommodating unit 12 may be controlled based on the relative humidity detected by the environmental sensor 430, which is capable of detecting temperature and humidity, to change the amount of toner discharged per pump. For example, when the relative humidity is a second relative humidity that is lower than the first relative humidity, the interval between the exhaust operation and the next intake operation, i.e., the time from compression to expansion of the pump unit 16 (adjustment time T3), is shortened. Specifically, the rotation speed of the toner accommodating unit 12 is increased, or, if the motor is capable of intermittent operation, the downtime between compression and expansion of the pump unit 16 is shortened.

[0053] <Second embodiment> The second embodiment will be described with reference to FIG. 12. In the first embodiment described above, it was shown that it is possible to accommodate changes in the type of toner used or changes in the specifications of the image forming apparatus without changing the hardware (components). However, the adjustment of the toner supply amount per unit supply operation described in the first embodiment can also be effective in improving the quality of the output within the same machine. In the second embodiment, a case will be described in which the control described in the first embodiment is applied to a different image forming mode. Note that parts that overlap with the first embodiment in the description and drawings will be assigned the same reference numerals and will not be described or illustrated again.

[0054] Typically, the amount of toner replenished per unit replenishment operation is set in accordance with the upper limit of toner consumption during image formation. In other words, it is set so that the amount of toner consumed can be tracked by the upper limit of the image formation speed of the image forming device 60 and the upper limit of the amount of toner that can be placed on a sheet. Therefore, if it is known in advance that the amount of toner consumed per unit time will be lower than the upper limit, it is possible to reduce the amount of toner replenished accordingly, which makes it easier to stabilize the balance of toner concentration in the developing device 3 and improves the quality of the finished product. One possible embodiment for achieving this is, for example, to provide a mode setting that prioritizes image quality (hereinafter referred to as image quality priority mode) in addition to a normal use setting (hereinafter referred to as normal mode) for the image forming device 60. The following describes in detail an embodiment for achieving this.

[0055] First, the image forming apparatus 60 of this embodiment can execute a normal mode as a first mode and an image quality priority mode as a second mode, and can change the image formation speed (process speed). The image quality priority mode is a mode in which image quality is prioritized at the expense of lower productivity of the image forming apparatus 60 than in the normal mode, and the image formation speed is slower than in the normal mode. In the image quality priority mode, which has a slower image formation speed, the rotation speed of the photosensitive drum 1 and the intermediate transfer belt 61, the sheet conveyance speed, etc. are slower.

[0056] Therefore, for example, when forming an image with the same image ratio, the amount of toner consumed per unit time is less than in the normal mode. Regarding changes in toner concentration in the developing device 3, the smaller the amount of toner consumed and supplied, the smaller the change in toner concentration in the developing device 3, which in turn reduces the change in concentration within the image and improves image quality. Therefore, in this embodiment, the interval from the exhaust operation to the next suction operation, i.e., the time from compression to expansion of the pump section 16 (adjustment time T3), is made shorter in the image quality priority mode than in the normal mode, thereby improving the quality of the finished product in the image quality priority mode.

[0057] This will be specifically described using the flowchart of FIG. 12. First, the user selects an image formation mode (S101). The mode change between the normal mode and the image quality priority mode is performed from the display panel 73 by the user operation, and is sent to the CPU 400 through the system controller 410 for processing (see FIG. 5). When the normal mode is selected in S101 (NO in S101), the process proceeds to S102 and S103, and the image formation speed (productivity of the image forming apparatus) is set to PV1, and the rotation speed of the drive motor 652 that rotates the toner container 12 is set to VT1 (S102, S103). In this embodiment, the default setting is the setting of the normal mode.

[0058] On the other hand, when the image quality priority mode is selected in S101 (YES in S101), the process proceeds to S104 and S105, and the image formation speed (productivity of the image forming apparatus) is set to PV2, and the rotation speed of the drive motor 652 that rotates the toner container 12 is set to VT2 (S104, S105). At this time, the relationship is such that the image formation speed is PV1 > PV2, and the rotation speed of the drive motor 652 is VT1 < VT2. As a result, the toner supply amount per unit supply operation (one supply operation) in the image quality priority mode is less than the toner supply amount per unit supply operation in the normal mode, and the balance of the toner concentration in the developing device 3 is likely to be stabilized. As described above, the user can select whether to prioritize image quality or productivity according to the application at that time, improving the quality of the product and the convenience. Note that, as described in the first embodiment, in this embodiment as well, when the motor can be intermittently driven, the stop time from compression to expansion of the pump unit 16 may be changed to control the toner supply amount per unit supply operation.

Explanation of Reference Numerals

[0059] 10Y, 10M, 10C, 10K ··· toner cartridge (developer supply container) 11 ··· cartridge gear (drive input unit) 11a ··· cam groove 12 ··· toner container (developer container) 15a...Discharge port 16 Pump section 17. Reciprocating link mechanism (drive conversion part) 17a...Protrusion (engaging part) 17b Link member 60 Image forming device 60a...Image forming apparatus main body 400···CPU (control unit) 605 Toner supply device (developer supply device) 652 Drive motor (drive unit)

Claims

1. a developer supply container detachable from the image forming apparatus body; a drive unit that drives the developer supply container attached to the image forming apparatus main body; a control unit that controls the drive unit, The developer supply container is a developer storage section capable of storing a developer; a discharge port for discharging the developer accommodated in the developer accommodating portion from the developer supply container; a pump section that expands and contracts to perform an exhaust operation of exhausting air from the inside of the developer supply container to the outside through the discharge port and an intake operation of sucking air from the outside of the developer supply container to the inside through the discharge port, and that is capable of discharging the developer together with the air from inside the developer supply container in conjunction with the exhaust operation; a drive conversion unit that converts the drive force input from the drive unit into a direction that expands or contracts the pump unit, The control unit is capable of executing a first mode and a second mode in which the image forming speed is slower than that of the first mode, and the second mode has a shorter interval from the exhaust operation to the next intake operation than the first mode. An image forming apparatus characterized by:

2. the drive unit is a motor, The control unit changes the interval from the exhaust operation to the next intake operation by changing the rotation speed of the motor.

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

3. The control unit changes the interval from the exhaust operation to the next intake operation by changing the stop time of the drive unit from the exhaust operation to the next intake operation.

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

4. the developer accommodating unit has a drive input unit to which a drive force is input from the drive unit, and is rotated by the drive force being input to the drive input unit to transport the developer therein toward the discharge port; The drive conversion unit has a cam groove formed on the outer circumferential surface of the developer accommodating unit, and a link member having one end fixed to the pump unit and the other end provided with an engaging portion that engages with the cam groove, and when the developer accommodating unit rotates, the link member moves along the cam groove to expand and contract the pump unit.

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

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