JP4027361B2 - Developer supply device and image forming apparatus - Google Patents

Description

The present invention relates to a developer supply device and an image forming apparatus .

  In an image forming apparatus such as a printer, a copier, or a facsimile, a toner image is formed by a developing device using a developer generally called toner or carrier to form an image. Since the toner is consumed together with the image formation, a toner storage container for storing toner such as a toner bottle and a toner cartridge is set in the apparatus main body in the image forming apparatus, and the toner is supplied from the container to the developing device. In this type of image forming apparatus, as a method for discharging the toner in the container, a method called auger is provided in the toner container for conveyance, or a spiral protrusion is provided on the inner surface of the cylindrical toner storage container. A system is known in which toner is conveyed to an outlet little by little by rotating a container called a screw bottle.

  However, the former transport method using an auger requires a member to be provided inside the container and must be rotated, resulting in a complicated structure. In addition, there is a problem that providing a member inside the container to be replaced increases the cost of consumables. The latter transport method using screw bottles is simple without providing a member inside the container, but a cylindrical container with an outlet on one side is arranged almost horizontally, so the amount of toner stored is relatively small and can be replaced. There was a problem that it was difficult to hold even when handling.

  As a toner conveyance system that can greatly reduce such a problem, the applicant of the present application has proposed a system in which toner is discharged from a container using a suction type pump and conveyed to an arbitrary position. In toner conveyance by this suction type pump, a flexible container can be used as a toner storage container, and therefore, it can be folded small after use, and the distribution cost can be greatly reduced even if collection by the manufacturer is required.

  By the way, when a flexible container is used as the toner storage container, the volume of the container can be reduced as the toner is replenished. Further, the volume of the container can be reduced by a method of sucking air inside the container when the toner end is reached. In this way, if the volume of the used container is already reduced at the time of replacement, the container can be easily handled and the folding operation after the removal becomes unnecessary, so that the reduction of the recovery cost can be promoted.

  However, when the volume of the toner storage container is reduced as described above, there is a problem in that the reduced shape is crushed, twisted, and the like, and does not become a constant shape. As described above, if the toner container is not reduced to a substantially constant shape, the container will not be stored well even when the used container is stored or transported for collection. Work is necessary, and the effect of volume reduction is not exhibited at all. Furthermore, the irregular volume reduction may leave a large amount of toner in the container depending on the shape.

SUMMARY OF THE INVENTION An object of the present invention is to provide a developer replenishing device and an image forming apparatus that can solve the above-described conventional problems and can reduce the volume of a flexible toner container to a substantially constant shape when the volume of the flexible toner container is reduced. Yes.

In order to achieve the above object, the present invention includes a developer storage container that stores a developer and is set downward from above, and a holding member that holds the set developer storage container. In the developer supply device for supplying the developer stored in the developer storage container to the developing device, the developer storage container has a base member configured to communicate with a toner passage of the developer supply device at a lower portion, and the base member The holding member has a taper that cuts into the developer storage container with the narrow shape of the developer storage container sandwiched between the holding members and approaches the holding member toward the bottom. A developer replenishing device characterized in that a convex portion is provided.

In the developer supply device of the present invention, it is effective if the developer in the developer storage container is discharged by suction of a suction means provided outside the container.

In order to achieve the above object, the present invention includes a developer storage container that stores the developer and is set downward from above, and a holding member that holds the set developer storage container. An image forming apparatus using the developer replenishing device according to claim 1 or 2 as a developer replenishing device for replenishing the developer stored in the developer container to the developing device is proposed.

According to the configuration of the first aspect, the reduced volume developer storage containers can be arranged in a substantially constant shape, and the storage performance during storage and transportation can be improved.

According to the configuration of the second aspect , since the developer in the developer storage container is discharged by the suction of the suction means provided outside the container, each time the developer is sucked by suction from the outside of the container, The container can be reduced in volume.

According to the configuration of the third aspect, it is possible to provide an image forming apparatus capable of reducing the volume of the container to a substantially constant shape by supplying the developer.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a schematic view showing a color copying machine as an example of a color image forming apparatus according to the present invention. In this color copying machine, a copying machine main body 100 is arranged at the center, and a sheet feeding unit 200 configured in a table shape is arranged below the copying machine main body 100. A scanner 300 is disposed above the copying machine main body 100, and an automatic document feeder 400 is disposed above the scanner 300. It is the composition which arranged.

  The copying machine main body 100 is provided with an intermediate transfer belt 10 as an image carrier constituted by a flexible endless belt wound around a plurality of rollers 14, 15, 16. In the intermediate transfer belt 10, one of the plurality of rollers 14, 15, 16 is rotationally driven by a driving device (not shown), whereby the intermediate transfer belt 10 is driven to run in the clockwise direction indicated by an arrow, and the other The roller rotates. Black, cyan, magenta, and yellow image forming units 18 are arranged side by side on the upper traveling side of the intermediate transfer belt 10 that travels in this way. That is, the tandem image forming apparatus 20 is configured by arranging four image forming units 18 on the running side between the rollers 14 and 15.

  The four image forming units 18 include a photosensitive drum 40 as a latent image carrier in contact with the intermediate transfer belt 10. Around the photosensitive drum 40, a charging device, a developing device, a cleaning device, a static eliminator, and the like are disposed. Further, a transfer device is disposed inside the intermediate transfer belt 10 at a position where the photosensitive drum 40 contacts the intermediate transfer belt 10. 57 is provided. In the present embodiment, the four image forming units 18 have the same structure, but the toner color of the developing device is divided into four colors of yellow, magenta, cyan, and black. Further, an exposure device 21 for irradiating the surface of each photosensitive drum with light-modulated laser light is disposed above each image forming unit 18, and this laser light is applied to the photosensitive drum between the charging device and the developing device. To do. Although the exposure apparatus 21 may be provided for each image forming unit 18, using the common exposure apparatus 21 is advantageous in terms of cost.

  On the other hand, a secondary transfer device 22 is provided on the opposite side of the intermediate transfer belt 10 from the tandem image forming device 20. The secondary transfer device 22 is arranged so that a secondary transfer belt 24, which is an endless belt, is wound between rollers 23, and the belt is pressed against the roller 16 via the intermediate transfer belt 10. In FIG. 1, a fixing device 25 for fixing a transfer image carried on the sheet is provided on the left side of the secondary transfer device 22.

  The secondary transfer device 22 described above is also provided with a sheet transport function for transporting the image-transferred sheet to the fixing device 25. Of course, a non-contact charger may be disposed as the secondary transfer device 22. In such a case, it is necessary to separately provide a sheet conveying device for conveying the transferred sheet to the fixing device 25.

  In the illustrated example, a sheet reversing device 28 for reversing the sheet so as to record images on both sides of the sheet is provided below the secondary transfer device 22 and the fixing device 25 in parallel with the tandem image forming device 20 described above. It has.

  Now, when making a copy using a color copying machine having such a configuration, a document is set on the document table 30 of the automatic document feeder 400. Alternatively, the automatic document feeder 400 is opened, a document is set on the contact glass 32 of the scanner 300, and the automatic document feeder 400 is closed and pressed by it.

  When a start switch (not shown) is pressed, when the document is set on the automatic document feeder 400, the document is transported and moved onto the contact glass 32, and then the document is set on the other contact glass 32. When this happens, the scanner 300 is immediately driven to travel on the first traveling body 33 and the second traveling body 34. Then, the first traveling body 33 emits light from the light source and further reflects the reflected light from the document surface toward the second traveling body 34, and is reflected by the mirror of the second traveling body 34 and passes through the imaging lens 35. The document is placed in the reading sensor 36 and the original content is read.

  Further, when a start switch (not shown) is pressed, the intermediate transfer belt 10 is rotated, and at the same time, the photoconductors 40 are rotated by the individual image forming units 18 so that the black, yellow, A magenta / cyan monochrome image is formed. Then, as the intermediate transfer belt 10 travels, the monochrome images are sequentially transferred to form a composite color image on the intermediate transfer belt 10.

  On the other hand, when a start switch (not shown) is pressed, one of the paper feed rollers 42 of the paper feed unit 200 is selectively rotated, and the sheet is fed out from one of the paper feed cassettes 44 provided in multiple stages in the paper bank 43, and the separation roller The sheet is separated one by one at 45 and put into the sheet feeding path 46, conveyed by the conveying roller 47, guided to the sheet feeding path 48 in the copying machine main body 100, abutted against the registration roller 49 and stopped.

  Alternatively, when manual feeding is selected, the sheet feeding roller 50 is rotated to feed out the sheets on the manual tray 51, separated one by one by the separation roller 52, and put into the manual feeding path 53. Stop by hitting.

  Then, the registration roller 49 is rotated in synchronization with the composite color image on the intermediate transfer belt 10, the sheet is fed between the intermediate transfer belt 10 and the secondary transfer device 22, and transferred by the secondary transfer device 22. Full color images are recorded on the sheet at once.

  The image-transferred sheet is conveyed by the secondary transfer device 22 and sent to the fixing device 25. The fixing device 25 applies heat and pressure to fix the transferred image, and then the switching sheet 55 is switched and discharged. The paper is discharged by the roller 26 and stacked on the paper discharge tray 27. Alternatively, it is switched by the switching claw 55 and put into the sheet reversing device 28, where it is reversed and guided again to the transfer position, and an image is recorded also on the back surface, and then discharged onto the discharge tray 27 by the discharge roller 26.

  On the other hand, the intermediate transfer belt 10 after image transfer is removed by the intermediate transfer body cleaning device 17 to remove residual toner remaining on the intermediate transfer belt 10 after image transfer, and is prepared for re-image formation by the tandem image forming apparatus 20.

FIG. 2 is an explanatory sectional view showing a toner replenishing device as a developer replenishing device according to the present invention.
In FIG. 2, reference numeral 60 denotes a developing device, and the developing device 60 is a so-called two-component developing device in which a developer in which toner and a carrier are mixed is stored. In such a developing device 60, since toner is consumed as the image is formed, it is necessary to replenish that much toner. Various methods have been proposed for toner replenishment control. Generally, the mixing ratio of toner and carrier is detected, or the density of a pattern image formed on the photosensitive drum 1 is detected, and the detection results are as follows. The toner replenishment signal is output based on the above.

On the developing device 60, a uniaxial eccentric screw pump (hereinafter referred to as a powder pump 80) is provided as a suction unit that sucks toner in the toner storage container 70. This powder pump 80 is made of an elastic member such as rubber and formed with a female screw type stator 82 formed with a double-pitch spiral groove, and is rotatably inserted into the stator 82 and made of metal, resin, or the like. And a male threaded rotor 81. The rotor 81 is connected to the drive shaft 84 by a spring pin or the like, and is driven to rotate when the drive shaft 84 is rotated. The periphery of the stator 82 is covered with a holder 83 fixed to the case 85, and a gap is provided between the inner peripheral surface of the holder 83 and the outer peripheral surface of the stator 82.

  The toner to be supplied to the developing device 60 is stored in a toner storage container 70, and the powder pump 80 and the toner storage container 70 are communicated with each other by a toner tube 86 as a supply path. The toner tube 86 may be of any type as long as it is pipe-shaped, but if it is made of a flexible tube, there is no restriction on the arrangement relationship between the toner container 70 and the developing device 60, and the degree of freedom in design is greatly increased. Increase. As the flexible tube, it is preferable to use a rubber material excellent in toner resistance, such as polyurethane, nitrile, EPDM or the like.

  The toner storage container 70 of the present embodiment is a sealed bag-like shape in which a flexible sheet having a single-layer or multi-layer structure having a thickness of about 60 to 200 μm made of a resin such as polyethylene or nylon or a paper is used without air inflow / outflow. Made in a container. Specifically, as shown in FIG. 3, it is a bag-like container generally called a gusset container, and is composed of four sheets 70a as shown in FIG. 4, and the edges of these sheets are heat-sealed. It becomes a bag-like container by adhering. The toner container 70 is shown in FIG. 3 in a state where the toner is filled and swelled, and in FIG. 5, the toner container 70 is shown in a folded state. The toner storage container 70 has a base member 71 fixed to the lower part thereof, and a seal valve 72 made of sponge, rubber or the like and having a slit (not shown) formed on the base member 71. The toner storage container 70 is generally a rectangular parallelepiped. However, in order to improve toner discharge and container setting properties, the opening is gradually reduced toward the base member 71 in the lower region. It is formed into a shape.

  The toner storage container 20 configured as described above is used by being set in a setting unit provided at an appropriate position of the image forming apparatus. The set portion is provided with a container holder 90 made of a hard material such as a resin that supports the toner storage container 70, and a nozzle 91 that is inserted into the toner storage container 70 via a seal valve 72. . As shown in FIG. 2, the nozzle 91 has a toner passage 93, and a tip 92 is formed at the tip of the nozzle 91 so that the nozzle 91 can be smoothly inserted into the seal valve 72.

Next, the operation mode of the toner replenishing device will be described.
When the toner of the developing device 60 is consumed, the powder pump 80 rotates and generates a suction pressure. The suction pressure is transmitted to the toner storage container 70 through the toner tube 86, and the toner is sucked into the powder pump 80 through the nozzle 91 and the toner tube 86 and is replenished to the developing device 60. At this time, if the space between the powder pump 80 and the toner container 70 is substantially sealed, the suction pressure can be transmitted to the toner without waste.

  Since the toner storage container 70 is a flexible bag, the toner storage container 70 is reduced in volume by the amount of toner sucked and reduced. At this time, as shown in FIG. 3, the toner storage container 70 is formed with folds 73 extending in the vertical direction on both side surfaces thereof. If the folds 73 are broken during volume reduction, the reduced toner storage is performed. Conveniently, the container 70 is in the state shown in FIG. That is, if the toner storage container 70 is folded along the crease 73, no irregular crushing or twisting occurs, so that a large amount of toner does not remain and the volume is reduced almost on a flat plate. It is very effective in reducing costs without taking up space during transportation for storage and collection.

  Therefore, as shown in FIG. 6, the toner replenishing device according to the present embodiment is provided with a convex portion 94 as a restricting means for inserting the fold 73 portion into the container holder 90 in which the toner storage container 70 is set. The protrusion 94 is a protrusion extending in the vertical direction like the crease 73, and the amount of biting into the toner storage container 70 indicated by symbol A in FIG. 6 is set to about 2 mm to 10 mm. The convex portions 94 are preferably provided on both the left and right sides of the holder 90 as shown in FIG.

  In the toner replenishing device configured as described above, when the volume is gradually reduced as a result of toner consumption as described above, the toner storage container 70 is regulated by the convex portion 94 and folded at the fold 73, so that the toner storage container 70 is It can be folded into an almost constant shape. For example, the toner storage container 70 may be provided with an air pump to supply air into the container to increase the fluidity of the stored toner, and in this case, the container becomes a toner end. However, the volume is not reduced by the air supplied by the air pump. Therefore, in this type of toner replenishing device, the volume of the container is reduced by operating the powder pump 80 after the toner end and removing air. Even at the time of volume reduction, by providing the convex portion 94, it is possible to reduce the volume of the toner storage container 70 to a preferable substantially constant shape.

  FIG. 7 shows another embodiment of the present invention, which is a drawing according to the toner container shown in FIG. 2, and the same members as those in FIG. In the replenishing device shown in FIG. 7, the convex portions 94 provided on the left and right sides of the container holder 90 are formed in a tapered shape so as to approach each other as they go downward.

  If the convex portion 94 is formed in a taper shape in this way, not only the container regulation at the time of volume reduction but also the container set by the convex portion 94 is guided when the toner storage container 70 is set in the container holder 90. A smooth container set can be made possible.

  8 and 9 are a longitudinal sectional view and a transverse sectional view showing still another embodiment of the present invention. In this embodiment, a regulating plate 95 as a regulating means is attached via a container holder 90 and a coil spring 96. It has been. When a new toner storage container 70 is mounted on the container holder 90, the regulation plate 95 comes into contact with the toner storage container 70 with elasticity by the coil spring 96. And if volume reduction of a container progresses by use, the control board 95 will move inside by a spring force, and the crease | fold 73 can be controlled.

  In FIG. 10, the toner storage container 70 includes a flexible inner bag body 75 and a rigid outer box 76 in which the inner bag body 75 is stored. When such a toner storage container 70 is a back-in-box type, after use, the inner bag body 75 is taken out from the outer box 76 and collected, and the outer box 76 can be used repeatedly. Also in the toner storage container 70, when the inner bag body 75 is taken out from the outer box 76, if the volume is reduced to a certain shape, the take-out operation is easy and it is advantageous in storing and transporting the inner bag body 75 after taking out.

  Therefore, in the back-in-box type toner storage container 70, a regulating means is provided on the surface of the outer box 76 that faces the fold 73. In the example of FIG. 10, a convex portion 77 is provided as a restricting means.

As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to the said embodiment, Various modifications can be made.
For example, in the above embodiment, toner is transferred, but a developer composed of toner and carrier can also be transferred. Further, the developing device is not limited to the two-component developing device, and may be a one-component developing device.

1 is a schematic diagram illustrating an overall configuration of an image forming apparatus according to the present invention. FIG. 4 is a cross-sectional explanatory view showing a toner supply device as a developer supply device according to the present invention. FIG. 6 is a perspective view showing a state when toner is full in an example of a toner container. FIG. 4 is an explanatory perspective view illustrating a basic configuration of the toner container shown in FIG. 3. FIG. 4 is a perspective view showing a state in which the volume is reduced by the toner storage container shown in FIG. 3. FIG. 3 is a cross-sectional view of a toner container portion in FIG. 2. FIG. 6 is a longitudinal sectional view of a toner container portion showing another embodiment of the present invention. FIG. 6 is a longitudinal sectional view of a toner container portion showing still another embodiment of the present invention. FIG. 9 is a cross-sectional view of the toner container portion of FIG. 8. FIG. 10 is a perspective view of a toner container portion showing still another embodiment of the present invention.

Explanation of symbols

60 Developing Device 70 Toner Storage Container 73 Crease 77 Convex Part 80 Powder Pump 90 Container Holder 94 Convex Part 95 Regulating Plate 96 Coil Spring

Claims (3)

A developer storage container that stores the developer and is set downward from above, and a holding member that holds the developer storage container that has been set, and the developer stored in the developer storage container In the developer replenishing device for replenishing
The developer container is
A base member configured to communicate with a toner passage of a developer supply device at a lower portion;
A shape that narrows toward the base member,
The holding member is provided with tapered convex portions that bite into the developer storage container across the narrow shape of the developer storage container and approach each other as it goes downward. Developer replenishing device.   2. The developer replenishing device according to claim 1, wherein the developer in the developer storage container is discharged by suction of a suction means provided outside the container. A developer storage container that stores the developer and is set downward from above, and a holding member that holds the developer storage container that has been set, and the developer stored in the developer storage container An image forming apparatus using the developer replenishing device according to claim 1 or 2 as a developer replenishing device for replenishing the toner.

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