JP2007264253A - Toner replenishing device and image forming apparatus equipped therewith - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a toner replenishing device capable of achieving the reduction of driving force for stirring toner and the securement of high stirring performance with simple structure inexpensively. <P>SOLUTION: In the toner replenishing device equipped with: a toner container for storing toner; a stirring means for stirring the toner by rotating a stirring sheet member 21 in the toner container; and a toner feeding means for feeding the toner stirred by the stirring means to the developing device, an auxiliary sheet member 28 thicker in thickness and shorter in width and length than the stirring sheet member 21 of the stirring means is attached to the stirring sheet member 21. The auxiliary sheet member 28 is attached to the surface on the upstream side (or downstream side) in the rotating direction of the stirring sheet member 21. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a toner replenishing device that stirs toner stored in a toner container and supplies the toner to a developing device, and an image forming apparatus including the toner replenishing device.

  In an image forming apparatus such as a copying machine or a laser beam printer that employs an electrophotographic system, an electrostatic latent image formed on an image carrier such as a photosensitive drum is developed with toner in a developing device and is visualized as a toner image. When the toner remaining in the developing device becomes less than a predetermined value due to consumption of toner, the toner is replenished to the developing device by the toner replenishing device.

  Here, the configuration of a conventional toner replenishing device will be described with reference to FIGS.

  FIG. 12 is a perspective view showing the internal structure of a conventional toner replenishing device, and FIG. 13 is a perspective view of the toner replenishing device viewed from the back side (a view in the direction of arrow A in FIG. 12).

  The toner replenishing device 7 shown in the figure is a cartridge that is integrally provided with a toner replenishing portion and a toner collecting portion, and as shown in FIG. A container 7A is provided, and a toner collection container 7B is provided in the lower half. In the toner container 7A, toner for replenishment is stored, and the agitating means for agitating the toner by the agitating sheet member 21 driven to rotate by the rotating shaft 20 and the toner in the toner container 7A are not contained. Toner feeding means for feeding to the illustrated developing device is provided.

  The stirring sheet member 21 of the stirring means is composed of a thin film (for example, a PET film having a thickness of 0.125 mm), its base end 21A is attached to the rotary shaft 20, and the other parts are free, This free part is divided into a plurality of strip-shaped divided pieces 21a, 21b, 21c, 21d, and 21e by a plurality of (four in the illustrated example) slits S, and each of the divided pieces 21a to 21e can be bent independently. It is.

  Further, as shown in FIG. 12, the toner feeding means is configured such that a conveying screw 23 is rotatably housed inside a circular toner replenishing tube 22, and a rectangular shape is formed above the toner replenishing tube 22. The toner inlet 22a is opened, and a toner outlet (not shown) connected to the toner discharge port 19a opened on the back side of the housing 19 is opened below the toner supply tube 22 as shown in FIG.

  By the way, as shown in FIG. 13, an end portion of the rotating shaft 20 protrudes from the rear side of the housing 19, and a large-diameter gear 24 is bound to the protruding portion. A small-diameter gear 25 and a small-diameter gear 26 a of the step gear 26 are engaged with the gear 24, and the large-diameter gear 26 b of the step gear 26 is a gear 27 connected to the shaft end of the conveying screw 23. Is engaged.

  Thus, when a driving force from a motor (not shown), which is a driving source, is input to the gear 25 and the gear 25 is rotationally driven, the rotation is decelerated by the gear 24 and transmitted to the rotary shaft 20. The stirring sheet member 21 attached to the rotary shaft 20 rotates in the toner container 7A to stir the toner and loosen it.

  The rotation of the gear 24 is transmitted to the conveying screw 23 through the step gear 26 and the gear 27, and the conveying screw 23 is rotationally driven in the toner supply pipe 22. Then, the toner dropped into the toner supply tube 22 from the toner inlet 22 a is conveyed to the toner outlet side through the toner supply tube 22 by the conveying screw 23 and discharged from the toner discharge port 19 a opened on the back side of the housing 19. Then, the toner is fed and supplied to a developing device (not shown) through a route (not shown).

  By the way, in this type of toner replenishing device 7, required stirring performance is ensured by changing the shape and thickness (rigidity) of the stirring sheet member 21.

On the other hand, in Patent Document 1, two types of stirring members are provided on the rotating shaft of the stirring means in order to suppress the driving force required for stirring the toner at the time of startup, and one stirring member (fixed stirring member) is connected to the rotating shaft. The other stirring member (rotating stirring member) is rotatably provided, and at least a part of the stirring region of the rotating stirring member is stirred prior to the stirring operation of the rotating stirring member. Is disclosed.
Japanese Patent Laying-Open No. 2005-077761

  However, in the conventional method of changing the shape and thickness (rigidity) of the stirring sheet member in order to ensure the required stirring performance, if the thickness of the stirring sheet member is reduced, the rigidity is low, so that stirring of the toner is required. Although the driving force can be kept small, there is a problem that if the solidified state of the toner is high, only the toner near the rotating shaft can be loosened, and the toner remains in a chakra shape. On the contrary, if the thickness of the stirring sheet member is increased, the effect of loosening the toner is enhanced, but not only a large driving force is required, but also the unpleasant rubbing that occurs when the stirring sheet member contacts the side wall of the toner container. There is a problem that the sound becomes loud.

  On the other hand, in the configuration described in Patent Document 1, the driving force required for stirring the toner can be reduced, but there is a problem in that the number of constituent members increases and the structure is complicated and the cost is unavoidable.

  SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and its object is to provide a toner replenishing device capable of realizing a reduction in toner agitation driving force and ensuring high agitation performance with a simple structure and at a low cost. An object of the present invention is to provide an image forming apparatus provided with this.

  In order to achieve the above object, the invention according to claim 1 is agitated by the toner container for storing the toner, the agitating means for agitating the toner by rotating the agitating sheet member in the toner container, and the agitating means. In the toner replenishing device including a toner feeding unit for feeding toner to the developing device, an auxiliary sheet member that is thicker and shorter in width and length than the stirring sheet member of the stirring unit is attached to the stirring sheet member. And

  The invention according to claim 2 is characterized in that, in the invention according to claim 1, the auxiliary sheet member is attached to the upstream surface of the stirring sheet member in the rotation direction.

  A third aspect of the invention is characterized in that, in the first aspect of the invention, the auxiliary sheet member is attached to a surface on the downstream side in the rotation direction of the stirring sheet member.

  The invention according to claim 4 is the invention according to any one of claims 1 to 3, wherein the auxiliary sheet member is formed in a comb-like shape, and a plurality of bendable divided pieces arranged in the rotation axis direction are provided. It is provided.

  The invention according to claim 5 is the invention according to claim 4, wherein the stirring sheet member is divided into a plurality of divided pieces by slits, and the divided pieces of the auxiliary sheet member are not overlapped with the slits of the stirring sheet member. It is characterized by having been arranged in.

  According to a sixth aspect of the present invention, at least a latent image forming unit that forms a latent image on an image carrier, and the latent image formed on the image carrier by the latent image forming unit is developed with toner to be visible. An image forming apparatus includes the developing device that forms an image and the toner replenishing device according to any one of claims 1 to 5 as a device that replenishes toner to the developing device.

  According to a seventh aspect of the invention, in the sixth aspect of the invention, the toner replenishing device is configured as a cartridge that can be attached to and detached from the image forming apparatus main body.

  According to the first aspect of the invention, since the toner is also stirred by the auxiliary sheet member that is thicker than the stirring sheet member, the toner is effectively stirred and uniformly loosened, and high stirring performance is ensured in the stirring means. Is done. Since the contact area of the auxiliary sheet member with the toner is kept small, the stirring resistance is kept small and the driving force is also kept small. Further, since the width of the auxiliary sheet member is set smaller than that of the stirring sheet member, the thick auxiliary sheet member does not contact the side wall of the toner container, and only the thin stirring sheet member has the toner. It comes in contact with the side wall of the container, and unpleasant rubbing noise can be kept low.

  Therefore, with a simple configuration in which the auxiliary sheet member is simply attached to the stirring sheet member, it is possible to achieve a reduction in toner stirring driving force and secure high stirring performance with a simple structure and at low cost.

  According to the second aspect of the present invention, since the auxiliary sheet member is attached to the upstream surface of the stirring sheet member in the rotational direction, the rigidity of the stirring sheet member is partially increased by the auxiliary sheet member, and the toner is supplied together with the auxiliary sheet member. It can be stirred effectively to loosen it uniformly.

  According to the third aspect of the invention, since the auxiliary sheet member is attached to the downstream surface in the rotation direction of the stirring sheet member, the thick auxiliary sheet member first stirs and loosens the toner, and the thin stirring sheet member supports the thin sheet. The toner can be stirred while being largely deformed without being affected by the sheet member.

  According to the fourth aspect of the present invention, since the auxiliary sheet member is formed in a comb-teeth shape, the stirring driving force can be kept small while enhancing the toner loosening effect of the auxiliary sheet member.

  According to the fifth aspect of the present invention, each of the divided pieces of the auxiliary sheet member is disposed at a position that does not overlap with the slit of the stirring sheet member, so that independent bending deformation of the divided piece of the stirring sheet member is assisted. Without being hindered by the sheet member, the agitation resistance of the toner can be released by the slit, and thereby the agitation driving force can be kept small.

  According to the invention described in claim 6, the effect of the invention described in claims 1-5 can be obtained in the image forming apparatus.

  According to the seventh aspect of the present invention, since the toner replenishing device is configured as a cartridge that can be attached to and detached from the image forming apparatus main body, when the toner for replenishment in the toner replenishing device runs out, it is easily replaced with a new toner replenishing device. And high maintainability is ensured.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

<Embodiment 1>
[Image forming apparatus]
First, the configuration of a color copying machine as an embodiment of an image forming apparatus according to the present invention will be described with reference to FIG.

  FIG. 1 is a front cross-sectional view of a color copying machine. The illustrated color copying machine includes a document reading unit 30 at an upper portion of a main body 100, and a magenta image forming unit 1M and a cyan image forming portion at an inner central portion of the main body 100. Unit 1C, yellow image forming unit 1Y and black image forming unit 1BK are arranged in a line at regular intervals.

  The original reading unit 30 includes an original table glass 31 on which an original is placed, an exposure lamp 32 that exposes and scans the original placed on the original table glass 31, and an original reflection that the exposure lamp 32 exposes and scans. A plurality of mirrors 33 for further reflecting the light image, a lens 34 for condensing the reflected light image, a full color sensor 35 such as a charge coupled device (CCD) in which the collected reflected light image is accumulated, and the like. Yes.

  The image forming units 1M, 1C, 1Y, and 1BK are provided with drum type electrophotographic photosensitive members (hereinafter referred to as “photosensitive drums”) 2a, 2b, 2c, and 2d as image carriers. Yes. Around the photosensitive drums 2a to 2d, there are primary chargers 3a, 3b, 3c, 3d, developing devices 4a, 4b, 4c, 4d, transfer rollers 5a, 5b, 5c, 5d as primary transfer means, and drums. Cleaning devices 6a, 6b, 6c and 6d are arranged, respectively.

  The photosensitive drums 1a to 1d are drum-shaped photosensitive members, and are rotationally driven at a predetermined process speed in a direction indicated by an arrow (counterclockwise in FIG. 1) by a driving device (not shown).

  The primary chargers 3a to 3d uniformly charge the surfaces of the photosensitive drums 2a to 2d to a predetermined potential by a charging bias applied from a charging bias power source (not shown).

  Further, the developing devices 4a to 4d contain magenta (M) toner, cyan (C) toner, yellow (Y) toner, and black (BK) toner, respectively, and are formed on the photosensitive drums 2a to 2d. The toner of each color is attached to each electrostatic latent image to develop each electrostatic latent image as a toner image of each color (visualization), and the toner is consumed and the developing devices 4a to 4d When a toner supply signal is issued because the remaining amount of toner is less than a certain value, toner of each color is supplied from the toner supply devices 7a, 7b, 7c, 7d according to the present invention to the developing devices 4a to 4d. The toner replenishing devices 7a to 7d are configured as cartridges that are detachable from the copying machine main body 100 as will be described later. It can be easily replaced and high maintainability can be ensured.

  Further, the transfer rollers 5a to 5d as primary transfer means are disposed so as to be in contact with the photosensitive drums 2a to 2d via the intermediate transfer belt 8 in each primary transfer portion. Here, the intermediate transfer belt 8 is stretched between the secondary transfer counter roller 9 and the tension roller 10 so as to be able to run on the upper surface side of each of the photosensitive drums 2a to 2d. The roller 9 is disposed so as to be in contact with the secondary transfer roller 11 via the intermediate transfer belt 8 in the secondary transfer portion. As the material of the intermediate transfer belt 8, for example, a dielectric resin such as polycarbonate, polyethylene terephthalate (PET), polyvinylidene fluoride (PVdF), or the like is selected. Although not shown, a belt cleaning device is installed outside the intermediate transfer belt 8 and in the vicinity of the tension roller 10 in order to remove transfer residual toner remaining on the surface of the intermediate transfer belt 8. .

  Incidentally, a laser scanner unit 40 is disposed below each of the image forming units 1M, 1C, 1Y, and 1BK inside the copying machine main body 100, and a paper feed cassette 50 is detachably installed at the bottom of the main body 100 below the image forming units. In this paper feed cassette 50, a plurality of transfer materials (paper) (not shown) are stacked and stored. In the vicinity of the paper feed cassette 50, a pickup roller 13 for feeding transfer materials from the paper feed cassette 50 to the conveyance path 12 one by one is provided.

  Further, the conveyance path 12 arranged in the vertical direction on one side of the copying machine main body 100 extends to a paper discharge tray 14 provided on the upper surface of the main body 100, and in the middle thereof, a pair of paper feed rollers 15. A registration roller pair 16, a fixing device 17 having a fixing roller 17a and a pressure roller 17b, and a paper discharge roller pair 18 are provided.

  Next, an image forming operation by the color copying machine having the above configuration will be described.

  When an image formation start signal is issued, the photosensitive drums 2a to 2d are driven to rotate in the direction of the arrow in FIG. 1 at a predetermined process speed in each of the image forming units 1M, 1C, 1Y, and 1BK, and these photosensitive drums 2a to 2d. Are uniformly charged by the primary chargers 3a to 3d. The laser scanner unit 40 emits a laser beam modulated by a color image signal for each color separated from the document reading unit 30 from a laser output unit 41, and the laser beam is emitted from a lens 42 and a plurality of mirrors 43. And the lens 44, the projections are projected onto the surfaces of the photosensitive drums 2a to 2d, and electrostatic latent images corresponding to the color image signals of the respective colors are formed on the photosensitive drums 2a to 2d, respectively.

  First, magenta toner is adhered to the electrostatic latent image formed on the photosensitive drum 2a of the magenta image forming unit 1M by the developing device 4a to which a developing bias having the same polarity as the charged polarity of the photosensitive drum 2a is applied. The electrostatic latent image is visualized as a magenta toner image. This magenta toner image is transferred to the arrow shown in FIG. 1 by the action of the transfer roller 5a to which a primary transfer bias having a polarity opposite to that of the toner is applied at the primary transfer portion (transfer nip portion) between the photosensitive drum 2a and the transfer roller 5a. Primary transfer is performed on the intermediate transfer belt 8 that is rotationally driven in the direction.

  The intermediate transfer belt 8 on which the magenta toner image has been primarily transferred as described above moves to the next cyan image forming unit 1C. In the cyan image forming unit 1C as well, the cyan toner image formed on the photosensitive drum 2b is transferred onto the magenta toner image on the intermediate transfer belt 8 at the primary transfer portion in the same manner as described above.

  Similarly, yellow and black toner images formed on the photosensitive drums 2c and 2d of the yellow and black image forming units 1Y and 1BK are respectively formed on the magenta and cyan toner images superimposed and transferred on the intermediate transfer belt 8. In each primary transfer portion, the images are sequentially overlapped, and a full-color toner image is formed on the intermediate transfer belt 8. The transfer residual toner that is not transferred onto the intermediate transfer belt 8 and remains on the photosensitive drums 2a to 2d is removed by the drum cleaning devices 6a to 6d, and is transferred by a waste toner transfer means (not shown) to be transferred to each toner. The toner is collected as waste toner in a toner collection container 7B (see FIG. 12) formed integrally with the supply devices 7a to 7d.

  Then, the pickup is picked up from the paper feed cassette 40 in accordance with the timing when the leading end of the full color toner image on the intermediate transfer belt 8 reaches the secondary transfer portion (transfer nip portion) between the secondary transfer counter roller 9 and the secondary transfer roller 11. The transfer material fed to the transport path 12 by the roller 13 and the paper feed roller pair 15 is transported to the secondary transfer section by the registration roller pair 16. Then, a full color toner image is secondarily transferred from the intermediate transfer belt 8 to the transfer material conveyed to the secondary transfer unit by the secondary transfer roller 11 to which a secondary transfer bias having a polarity opposite to that of the toner is applied. The

  Thus, the transfer material onto which the full-color toner image has been transferred is conveyed to the fixing device 17, and the full-color toner image is heated and pressed at the fixing nip portion between the fixing roller 17a and the pressure roller 17b. After the heat fixing on the surface of the transfer material, the transfer material on which the toner has been fixed is discharged onto the paper discharge tray 14 by the paper discharge roller pair 18 to complete a series of image forming operations. The secondary transfer residual toner that is not transferred onto the transfer material but remains on the intermediate transfer belt 8 is removed by a belt cleaning device (not shown), and is transported by a waste toner transport means (not shown) to collect toner (not shown). It is collected in the container as waste toner.

[Toner supply device]
Next, the toner replenishing devices 7a to 7d according to the present invention will be described.
[Example 1]

  2 is an exploded perspective view of the stirring sheet member and auxiliary sheet member of the toner replenishing device according to the present invention, FIG. 3 is a front view of the stirring sheet member and auxiliary sheet member, and FIG. 4 is a stirring sheet member and auxiliary sheet during toner stirring. FIG. 3 is a front view of the inside of a toner container showing a state of members.

  The toner replenishing devices 7a to 7d according to the present invention are different from the conventional one shown in FIGS. 12 and 13 only in the configuration of the stirring means, and the other configurations are the same. Description is omitted. Since the four toner replenishing devices 7a to 7d have the same configuration, only one toner replenishing device 7a will be described below.

  The present embodiment is characterized in that an auxiliary sheet member 28 that is thicker and shorter in width and length than the stirring sheet member 21 is attached to the stirring sheet member 21 that constitutes the stirring means for stirring the toner in the toner container 7A. And

  Here, the stirring sheet member 21 is formed of a thin film (for example, a PET film having a thickness of 0.125 mm) as in the conventional case, and its base end 21A is attached to the rotary shaft 20 (see FIG. 4). 2 and 3, as shown in FIGS. 2 and 3, this free part is divided into five strip-shaped divided pieces 21a, 21b, 21c, 21d, and 21e having different shapes by the four slits S. The divided pieces 21a to 21e can be bent independently. Note that three attachment holes 29 are formed in the base end portion 21A of the stirring sheet member 21 at appropriate intervals in the width direction, and the stirring sheet member is inserted by screws (not shown) inserted through the attachment holes 29. 21 has a base end 21 </ b> A attached to the rotary shaft 20.

  On the other hand, as shown in FIGS. 2 and 3, the auxiliary sheet member 28 is formed in a comb-like shape and has three bendable divided pieces 28 a arranged in the direction of the rotation axis. Here, each divided piece 28a is formed in a tapered shape toward the tip, and the tip is rounded in a semicircular shape. The auxiliary sheet member 28 is made of a film thicker than the thickness of the stirring sheet member 21 (for example, a PET film having a thickness of 0.5 mm), and the width b and the length h are the width B of the stirring sheet member 21. And shorter than the length H (b <B, h <H).

  Further, the auxiliary sheet member 28 has a base end portion 28A excluding the divided piece 28a attached to the surface upstream of the base end portion 21A of the stirring sheet member 21 in the rotational direction (front side in FIGS. 2 and 3) with an adhesive. It is attached (the hatched area shown in FIG. 3 is an attachment portion), and each divided piece 28a is free and can be bent independently. Each divided piece 28a of the auxiliary sheet member 28 is disposed at a position where it does not overlap with the slit S of the stirring sheet member 21, and the two divided pieces 21b and 21c adjacent to each other with the slit S of the stirring sheet member 21 interposed therebetween. And it is not located over the split pieces 21c and 21d. The base end portion 28A of the auxiliary sheet member 28 is formed with three rectangular cutouts 28b, 28c, and 28d for avoiding the three attachment holes 29 formed in the stirring sheet member 21.

  Thus, when the rotary shaft 20 is driven to rotate by receiving a driving force from a motor (not shown), the stirring sheet member 21 attached to the rotary shaft 20 and the auxiliary sheet member 28 attached thereto are used as toner. The container 7A is integrally rotated in the direction of the arrow in FIG. 4 (counterclockwise), and the replenishing toner stored in the toner container 7A is stirred to loosen it. At this time, the stirring sheet member 21 receives the stirring resistance from the toner and bends and deforms in the anti-stirring direction as shown in FIG. 4, but the auxiliary stirring sheet 28 attached upstream in the rotational direction is bent in the same direction. Deform.

  Here, as described above, since the auxiliary sheet member 28 is thicker than the thickness of the stirring sheet member 21, the auxiliary sheet member 28 has high rigidity and is not easily deformed, and partially increases the rigidity of the stirring sheet member 21. For this reason, even if the toner is solidified in the toner container 7A, the toner is effectively stirred by the stirring sheet member 21 and the auxiliary sheet member 28 and is uniformly loosened. At this time, as described above, the width b and the length h of the auxiliary sheet member 28 are set shorter than the width B and the length H of the stirring sheet member 21 (b <B, h <H). Is smaller than that of the stirring sheet member 21, and as a result, the stirring resistance of the toner is suppressed to be small and the driving force is also suppressed to be small. Further, since each divided piece 28a of the auxiliary sheet member 28 is disposed at a position where it does not overlap the slit S of the stirring sheet member 21, independent bending deformation of the divided pieces 21a to 21e of the stirring sheet member 21 is assisted. The stirring resistance of the toner can be released by the slit S without being obstructed by the sheet member 28, and thus the stirring driving force can be kept small.

  Further, since the width b of the auxiliary sheet member 28 is set smaller than the width B of the stirring sheet member 21, the thick auxiliary sheet member 28 does not come into contact with the side wall of the toner container 7A. Since only the thin stirring sheet member comes into contact with the side wall of the toner container 7 </ b> A, it can be suppressed to a level at which an irritating and unpleasant rubbing noise is hardly noticed.

As described above, according to the present invention, a simple configuration in which the auxiliary sheet member 28 having a simple shape is simply attached to the stirring sheet member 21, and a reduction in the stirring driving force of the toner and the securing of high stirring performance are simplified. In addition, it can be realized at low cost. In particular, since the auxiliary sheet member 28 is formed in a comb-teeth shape, the stirring driving force can be reduced while increasing the toner loosening effect of the auxiliary sheet member 28.
[Example 2]

  Next, Example 2 of Embodiment 1 will be described with reference to FIGS.

  FIG. 5 is an exploded perspective view of the stirring sheet member and the auxiliary sheet member of the toner replenishing device according to the present embodiment, and FIG. 6 is a front view of the stirring sheet member and the auxiliary sheet member. In these drawings, FIGS. The same reference numerals are given to the same elements as those shown in FIG.

  This embodiment is the same as the first embodiment except that the shape of the three divided pieces 28a of the auxiliary sheet member 28 is a rectangular strip shape. In this embodiment, the auxiliary sheet member 28 is also divided. The base end portion 28A excluding the piece 28a is adhered to the surface of the base end portion 21A of the stirring sheet member 21 on the upstream side in the rotational direction (front side in FIGS. 5 and 6) with an adhesive (hatching shown in FIG. 6). The area is the sticking part).

  Therefore, also in the present embodiment, similarly to the first embodiment, it is possible to realize the reduction of the toner stirring driving force and the securing of high stirring performance with a simple structure and low cost.

<Embodiment 2>
Next, Embodiment 2 of the present invention will be described.
[Example 1]

  FIG. 7 is an exploded perspective view of the stirring sheet member and the auxiliary sheet member of the toner replenishing device according to Example 1 of the second embodiment, FIG. 8 is a front view of the stirring sheet member and the auxiliary sheet member, and FIG. FIG. 5 is a front view of the inside of the toner container showing the state of the stirring sheet member and the auxiliary sheet member. In these drawings, the same elements as those shown in FIGS. The re-explanation about is omitted.

  In this example, the auxiliary sheet member 28 used in Example 1 of the first embodiment is attached to the surface on the downstream side (front side in FIG. 8) in the rotation direction of the base end portion 21 </ b> A of the stirring sheet member 21. The other features are the same as those of the first embodiment of the first embodiment.

  Thus, when the rotating shaft 20 (see FIG. 9) is driven to rotate by receiving a driving force from a motor (not shown), the stirring sheet member 21 attached to the rotating shaft 20 and the auxiliary member attached thereto. The sheet member 28 rotates in the toner container 7A in the direction of the arrow (counterclockwise) in FIG. 9, and stirs the replenishing toner stored in the toner container 7A to loosen it. At this time, since the auxiliary sheet member 28 is attached to the surface on the downstream side in the rotation direction of the stirring sheet member 21, the thick auxiliary sheet member 28 first stirs the toner to loosen it, and the thin stirring sheet member 21 stirs the toner while being largely deformed independently without being affected by the auxiliary sheet member 28.

  Therefore, even if the toner is solidified in the toner container 7A, the toner is effectively stirred by the stirring sheet member 21 and the auxiliary sheet member 28 and is uniformly loosened. At this time, the width b and length h of the auxiliary sheet member 28 are set shorter than the width B and length H of the stirring sheet member 21 (b <B, h <H). The contact area with the toner is suppressed to be smaller than that of the agitation sheet member 21. As a result, the agitation resistance of the toner is suppressed to be small and the driving force is also suppressed to be small. Further, since each divided piece 28a of the auxiliary sheet member 28 is disposed at a position where it does not overlap the slit S of the stirring sheet member 21, independent bending deformation of the divided pieces 21a to 21e of the stirring sheet member 21 is assisted. The stirring resistance of the toner can be released by the slit S without being obstructed by the sheet member 28, and thus the stirring driving force can be kept small.

  Further, since the width b of the auxiliary sheet member 28 is set smaller than the width B of the stirring sheet member 21, the thick auxiliary sheet member 28 does not come into contact with the side wall of the toner container 7A. Only the thin stirring sheet member 21 comes into contact with the side wall of the toner container 7 </ b> A, and is suppressed to such an extent that an unpleasant and unpleasant rubbing noise is hardly noticed.

As described above, according to the present embodiment, a simple configuration in which the auxiliary sheet member 28 having a simple shape is simply attached to the agitation sheet member 21, and a reduction in toner agitation driving force and a high agitation performance are ensured. In addition, it can be realized at low cost.
[Example 2]

  Next, Example 2 of the second embodiment will be described with reference to FIGS.

  10 is an exploded perspective view of the stirring sheet member and the auxiliary sheet member of the toner replenishing device according to the present embodiment, and FIG. 11 is a front view of the stirring sheet member and the auxiliary sheet member. In these drawings, FIGS. The same reference numerals are given to the same elements as those shown in FIG.

  This embodiment is the same as the first embodiment except that the shape of the three divided pieces 28a of the auxiliary sheet member 28 is a rectangular strip shape. In this embodiment, the auxiliary sheet member 28 is also divided. A base end portion 28A excluding the piece 28a is attached to the surface of the base end portion 21A of the stirring sheet member 21 on the downstream side in the rotation direction (front side in FIG. 11) with an adhesive (the hatched area shown in FIG. 11 is attached). It is the wearing part).

  Therefore, also in the present embodiment, similarly to the first embodiment, it is possible to realize the reduction of the toner stirring driving force and the securing of high stirring performance with a simple structure and low cost.

  The present invention can be applied to a color copying machine, a monochrome copying machine, other arbitrary image forming apparatuses, and a toner replenishing device provided in the image forming apparatus.

A configuration of a color copying machine as an embodiment of an image forming apparatus according to the present invention will be described with reference to FIG. FIG. 3 is an exploded perspective view of a stirring sheet member and an auxiliary sheet member of the toner supply device according to Example 1 of Embodiment 1 of the present invention. FIG. 5 is a front view of a stirring sheet member and an auxiliary sheet member of the toner supply device according to Example 1 of Embodiment 1 of the present invention. FIG. 5 is a front view of the inside of the toner container showing the state of the stirring sheet member and the auxiliary sheet member during toner stirring of the toner replenishing device according to Example 1 of Embodiment 1 of the present invention. FIG. 6 is an exploded perspective view of a stirring sheet member and an auxiliary sheet member of a toner supply device according to Example 2 of Embodiment 1 of the present invention. FIG. 6 is a front view of a stirring sheet member and an auxiliary sheet member of the toner supply device according to Example 2 of Embodiment 1 of the present invention. FIG. 6 is an exploded perspective view of a stirring sheet member and an auxiliary sheet member of a toner supply device according to Example 1 of Embodiment 2 of the present invention. FIG. 10 is a front view of a stirring sheet member and an auxiliary sheet member of the toner supply device according to Example 1 of Embodiment 2 of the present invention. FIG. 6 is a front view of the inside of a toner container showing a state of a stirring sheet member and an auxiliary sheet member during toner stirring of the toner replenishing device according to Example 1 of Embodiment 2 of the invention. FIG. 6 is an exploded perspective view of a stirring sheet member and an auxiliary sheet member of a toner supply device according to Example 2 of Embodiment 2 of the present invention. FIG. 10 is a front view of a stirring sheet member and an auxiliary sheet member of a toner supply device according to Example 2 of Embodiment 2 of the present invention. It is a perspective view which shows the internal structure of the conventional toner replenishing apparatus. FIG. 13 is a perspective view of a conventional toner replenishing device viewed from the back side (a view in the direction of arrow A in FIG. 12).

Explanation of symbols

1M, 1C, 1Y, 1BK Image forming units 2a, 2b, 2c, 2d Photosensitive drums 3a, 3b, 3c, 3d Primary chargers 4a, 4b, 4c, 4d Developing devices 5a, 5b, 5c, 5d Transfer rollers 6a, 6b , 6c, 6d Drum cleaning device 7a, 7b, 7c, 7d Toner replenishing device 7A Toner container 8 Intermediate transfer belt 9 Secondary transfer counter roller 10 Tension roller 11 Secondary transfer roller 12 Conveyance path 13 Pickup roller 14 Discharge tray 15 Feed Paper roller pair 16 Registration roller pair 17 Fixing device 18 Paper discharge roller pair 19 Housing of toner replenishing device 20 Rotating shaft 21 Stirring sheet member 21A Stirring sheet member base end portions 21a to 21e Stirring sheet member split piece 22 Toner replenishing tube 23 Conveying screw 24-27 Gear 28 Auxiliary sheet Member 28A Base end portion of auxiliary sheet member 28a Split piece of auxiliary sheet member S Slit

Claims (7)

A toner container for storing toner; a stirring unit that rotates the stirring sheet member in the toner container to stir the toner; and a toner feeding unit that feeds the toner stirred by the stirring unit to the developing device. In the toner supply device,
A toner replenishing device, wherein an auxiliary sheet member that is thicker and shorter in width and length than the stirring sheet member of the stirring means is attached to the stirring sheet member.   The toner replenishing device according to claim 1, wherein the auxiliary sheet member is attached to a surface upstream of the stirring sheet member in the rotation direction.   2. The toner replenishing device according to claim 1, wherein the auxiliary sheet member is attached to a surface on the downstream side in the rotation direction of the stirring sheet member.   The toner replenishing device according to any one of claims 1 to 3, wherein the auxiliary sheet member is formed in a comb-like shape and provided with a plurality of bendable divided pieces arranged in a rotation axis direction.   5. The toner replenishing device according to claim 4, wherein the stirring sheet member is divided into a plurality of divided pieces by slits, and the divided pieces of the auxiliary sheet member are arranged at positions not overlapping with the slits of the stirring sheet member. .   A latent image forming unit that forms at least a latent image on the image carrier, a developing device that develops the latent image formed on the image carrier by the latent image forming unit with a toner, and visualizes the latent image; and An image forming apparatus comprising the toner replenishing device according to claim 1 as a device for replenishing toner to a developing device.   7. The image forming apparatus according to claim 6, wherein the toner replenishing device is configured as a cartridge that can be attached to and detached from the image forming apparatus main body.

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