JP4351959B2 - Agent replenishing device and image forming apparatus - Google Patents

Description

The present invention is a developer where is a mixture of toner or carrier or toner and carrier, to a supply for replenishing device and an image forming apparatus to the developing device from the accommodating dosage container.

  In image forming apparatuses such as printers, copiers, facsimiles, and multifunction machines having at least two of these functions, a developing device that develops an electrostatic latent image using a two-component developer composed of toner and carrier is often used. Yes. In this type of image forming apparatus, the toner density in the developing device is kept almost constant, so that when toner is consumed together with image formation, the toner is replenished accordingly. The toner to be replenished to the developing device is stored in a toner storage container of a toner bottle or a toner cartridge, and the container is replaced when the toner in the container runs out.

JP 2000-47765 A JP 2000-81778 A JP 2000-98721 A JP 2003-131485 A

  In addition, toner replenishment from the toner container to the developing device is mainly performed using a mechanical auger. However, as described in Patent Documents 1 to 4, a powder pump called a MONO pump is used. Has been proposed and implemented. Compared with a conventional auger or the like using this powder pump, this powder pump has the advantages that the degree of freedom of the setting position of the toner storage container is increased and that unnecessary stress is not applied to the toner to be transferred.

  By the way, when the toner container is removed from the image forming apparatus by replacing the toner container, or while the toner is being replenished, the toner in the toner container may spill into the apparatus or the toner container may be stained with toner. In particular, since the contamination of the toner storage container leads to the user's hand becoming dirty, there is a demand for reducing the contamination of the toner storage container as much as possible.

  Further, when a powder pump is used for the toner replenishing method, since the path from the toner container to the powder pump is sealed, when toner is replenished to the developing device, the air pressure corresponding to the reduced toner volume in the toner container Will drop. This reduces the pressure difference between the toner container and the powder pump, which is disadvantageous for stable toner supply.

  Further, in the toner transfer method using the powder pump described above, toner is discharged from the bottom of the toner storage container. However, if the toner on the top of the container remains without falling to the bottom, the remaining amount of toner increases during replacement.

An object of the present invention is to provide an agent replenishing device and an image forming apparatus that are less contaminated with toner, can be stably replenished with toner, and have little residual toner in an agent storage container at the time of replacement. It is said.

In order to achieve the above-mentioned object, the present invention is directed to suction of screw pump means from an agent storage container having a storage portion for storing a developer therein and a discharge port for discharging the developer at the bottom of the storage portion. In the agent replenishing device for replenishing the developer discharged from the discharge port by force, the storage portion of the agent storage container is made of a resin that is not deformed by the suction force of the screw pump means, and the four side surfaces thereof are in the vertical direction. A box shape in which an inclined surface is formed in a direction to be narrowed from the middle of the extending surface toward the discharge port, and the storage portion is formed with a drop promoting surface that is convex on the inner surface side in at least one of the inclined surfaces. And a filter for taking in gas from the outside is provided, and the discharge port of the agent storage container is closed by a shutter, and the screw pump means when used Is connected in a sealed state, wherein the housing section proposes to replenishing device, characterized in that the gas is Toriira from outside through the filter by suction force of the screw pump means.

The present invention is effective when the filter is provided on the upper surface of the storage portion .

In order to achieve the above object, the present invention proposes an image forming apparatus using the agent replenishing device according to claim 1 or 2 .

According to the present invention, by reducing the opening for discharging the toner, it is possible to improve the user operability by suppressing contamination of the toner container.
Furthermore, according to the present invention, stable discharge of the toner can be obtained by keeping the air pressure in the toner storage container constant with the outside air.

  Furthermore, according to the present invention, residual toner at the time of replacement can be reduced by increasing the inclination of the inclined surface of the toner storage container.

The best mode for carrying out the present invention will be described below with reference to the accompanying drawings.
FIG. 1 is a schematic view showing a color copying machine as an example of an 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 at the lower part. A scanner 300 is provided above the copying machine main body 100, and an automatic document feeder 400 is provided 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 means 18 on the running side between the roller 14 and the roller 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. 37 is provided. In the present embodiment, the four image forming units 8 have the same structure, but the color of the toner of the developing device is divided into four colors of black, cyan, magenta, and yellow. 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 a sheet is provided on the left side of the secondary transfer device 22. The fixing device 25 of this embodiment includes a pressure roller 27 and a fixing belt 26 that is an endless belt pressed against the pressure roller 27.

  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 photosensitive member 40 is rotated by the individual image forming means 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. Are discharged and stacked on the discharge tray 57. 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 57 by the discharge roller 56.

  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 a configuration diagram of a toner supply mechanism for supplying toner to the developing device of the image forming unit 18.
In FIG. 2, a toner storage container 80 storing toner to be replenished to the developing device 60 is set in a setting unit (not shown) provided in the copying machine main body 100. The toner storage container 80 includes a bottle-shaped toner storage portion 81 and a base portion 82 in which a toner discharge port 83 is formed. The toner storage portion 81 can be a flexible and deformable bag-like body. In the embodiment, it is made of a resin such as polyethylene or nylon. The base part 82 is also made of a resin such as polyethylene or nylon, and the toner discharge port 83 is closed by a seal 84 that is in close contact with the outer periphery of the shutter 85.

  When the toner storage container 80 is set in the setting portion, as shown in FIGS. 2 and 3, the shutter 85 is pushed sideways by the nozzle 90, and the opening 92 of the nozzle 90 and the toner discharge port 83 are in communication with each other. Become. Reference numeral 91 denotes a spring for returning the shutter 85, which is used to return the shutter 85 to a position where the toner discharge port 83 is closed when the toner storage container 80 is taken out from the set portion. The nozzle 90 has a single tube structure, and a toner transfer tube 59 is connected to the end opposite to the insertion side of the nozzle 90.

  On the other hand, the developing device 60 is provided with a sub hopper 61 as a second toner storage portion at the top thereof, and the toner in the toner storage container 80 is temporarily stored in the sub hopper 61. On the sub hopper 61, screw pump means 70 is provided as toner transfer means for transferring the toner in the toner storage container 80 to the sub hopper 61. This screw pump means 70 is a uniaxial eccentric screw pump, and is made of a rotor 71 made of a screw shape eccentric with a material having rigidity such as metal, and an elastic body such as rubber, and is a double screw shape. And a holder 73 made of a resin material or the like that wraps these and forms a powder conveyance path. In the rotor 71, a driving shaft 74 connected by a pin joint is drivingly connected to driving means (not shown).

A toner suction part 77 is provided at the tip of the holder 73, that is, the right end in FIG. 2, and the toner transfer tube 59 is connected to the toner suction part 77. As the toner transfer tube 59, for example, a flexible tube having a diameter of 4 to 10 mm and made of a rubber material having excellent toner resistance (for example, polyurethane, nitrile, EPDM, silicon, etc.) is extremely used. An effective and flexible tube can be easily piped up and down, left and right. If the powder pump 70 described above is used, the toner in the toner storage container 80 is smoothly conveyed even when the toner discharge port of the toner storage means is at a lower position in the vertical direction than the toner receiving port of the sub hopper 61. be able to.

  As shown in FIG. 2, the sub popper 61 is divided in the direction of gravity by an upper and lower partition member 64, and an upper chamber 62 and a lower chamber 63 are provided. The upper chamber 62 having a larger floor area than the lower chamber 63 is provided with a pair of upper screws 67 that are driven to rotate in opposite directions, and the lower chamber 63 is provided with one lower screw 68.

As shown in FIG. 4, the toner storage portion 81 of the toner storage container 80 has a substantially rectangular parallelepiped upper surface in the set state, and a filter 86 as an air pressure adjusting member that adjusts the air pressure in the toner storage portion on the upper surface. Is installed. Since the filter 86 may be clogged with toner if it is kept in direct contact with the toner, it is preferable to install the filter 86 on the upper surface where the toner does not touch during use or on the side surface close to the upper surface.

  As shown in FIG. 5, the toner storage container 80 has an upper surface E, front and rear side surfaces A1, B1, and left and right side surfaces C1, D1, which are vertical surfaces extending from the four sides of the upper surface E. Inclined surfaces A2, B2, C2, and D2 are provided in a direction to narrow toward the discharge port 83 from the middle. At this time, if the angle θ formed by the vertical surfaces that are the side surfaces A1, B1, C1, and D1 and the inclined surface inclined surfaces A2, B2, C2, and D2 is set to a relatively steep slope in the range of 10 ° to 30 °, the toner is It can fall along the slope and reduce the remaining amount of toner at the time of replacement.

  Incidentally, if the inclined surface of the toner storage container 80 is steeply inclined as described above, the remaining amount of toner can be reduced, but the capacity of the toner container is reduced accordingly. The toner storage container having a small capacity is troublesome for the user because its replacement frequency increases.

  Therefore, the toner storage container 80 shown in FIG. 6 does not reduce the toner capacity so much and forms a convex portion 88 as a fall promotion surface protruding inward on the inclined surface portion of the container so as to form a steeply inclined portion. ing. The convex portion 88 has a length in the vertical direction that reaches the base portion 82 from slightly above the inclined surface, and the horizontal direction may be about 2 to 1/3 of the entire width at the center. The convex part 88 which becomes substantially full width like FIG. 7 may be sufficient. And the cross-sectional shape in a container is formed in the inverted V-shaped mountain shape. Although this convex part 88 may be provided by sticking a convex thing inside the container, etc., it is preferable from the point of manufacturing cost etc. to form the convex part 88 inside by denting from the outer side of a container. Further, the number of convex portions 88 may be provided on one of the four inclined surface portions, or may be provided on all inclined surfaces. Further, as shown in FIGS. 6 and 7, it is effective to provide two opposing inclined surfaces.

  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, the agent storage container is a toner storage container and the developer supply device is a toner supply device. However, the agent storage container may be a carrier storage container that stores a carrier instead of a toner storage container. The developer supply device may be a carrier supply device. If the carriers are sequentially replenished in this way, the carriers are replaced little by little without being replaced at a time, so that the image quality can be maintained at a certain level for a long time. The agent storage container can also be configured as a premix developer container in which toner and carrier are mixed.

1 is a schematic view of an image forming apparatus using a toner storage container according to the present invention. 2 is a cross-sectional explanatory view showing a toner replenishing device of the image forming apparatus. FIG. FIG. 6 is a cross-sectional view illustrating a state where a nozzle is inserted into a toner storage container. FIG. 3 is a perspective view of a toner storage container according to the present invention. It is a perspective view explaining each surface of the toner storage container. FIG. 4 is a broken sectional view of a toner storage container showing an example of a fall promoting surface. FIG. 6 is a broken cross-sectional view of a toner storage container showing another example of a fall promoting surface.

Explanation of symbols

60 Developing Device 61 Sub Hopper 70 Screw Pump Means 80 Toner Storage Container 81 Storage Portion 82 Base Portion 83 Discharge Port 85 Shutter 86 Filter 88 Projection

Claims (3)

The developer discharged from the discharge port by the suction force of the screw pump means from the agent storage container having a storage unit for storing the developer inside and a discharge port for discharging the developer at the bottom of the storage unit. In the agent replenishing device for replenishing the developing device,
The storage part of the agent storage container is made of a resin that is not deformed by the suction force of the screw pump means, and has a box shape in which four side surfaces are inclined in the direction of narrowing toward the discharge port from the middle of the surface extending in the vertical direction. And the storage part is provided with a filter for taking in gas from the outside while forming a drop promoting surface convex on the inner surface side on at least one of the inclined surfaces,
The outlet of the agent storage container is closed by a shutter;
An agent replenishing device characterized in that when in use, the agent is connected to the screw pump means in a sealed state, and gas is taken into the storage portion from the outside through the filter by the suction force of the screw pump means. In replenishing device of claim 1, wherein the filter characteristic to replenishing device that is provided on the upper surface of the housing portion.   An image forming apparatus using the agent replenishing device according to claim 1.

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