JP2006258837A - Toner replenishing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a toner replenishing device which stabilize toner supply to a developing unit and reduces the generation of rubbing noise accompanying toner agitation irrespective of the amount of toner in the device. <P>SOLUTION: A casing 1 of the toner replenishing device includes an agitating paddle 2 which comprises a rotary shaft 2a, an arm portion 2b, and a weight type agitating member 15 and agitates and carries toner in the casing 1 and a carrying screw 3 which supplies the toner carried by the agitating paddle 2 to a developing device. The agitating member 15 comprises a rod-shaped toner agitation portion 13 which extends along the paper surface direction in Fig. and a connecting portion 14 which connects the toner agitating portion 13 turnably in parallel to a tip shaft 7. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a toner replenishing device that supplies toner to a developing unit of an image forming apparatus such as a copying machine, a facsimile machine, and a printer, and more particularly to a toner stirring method in the toner replenishing device.

  In an image forming apparatus using an electrophotographic system such as a copying machine, a printer, or a FAX, a powder developer (hereinafter referred to as toner) is mainly used, and an electrostatic image formed on an image carrier such as a photosensitive drum. In general, the latent image is visualized with toner, and after the toner image is transferred onto a recording medium, a fixing process is performed.

  FIG. 6 shows a conventional image forming apparatus (for example, a printer) 100 using the developing unit 21. The image forming apparatus 100 includes a photosensitive drum 41, a charging unit 42, an image writing unit (laser scanning unit) 43, a developing unit 21, a toner replenishing device 44, a toner replenishing device detection sensor 45, a transfer unit 46, and a cleaning unit 47. , A sheet storage unit 51, a conveyance unit 52, a fixing unit 53, and a paper discharge unit 54.

  The photosensitive drum 41 is formed, for example, by laminating a photosensitive layer on an aluminum drum, and the charging unit 42 charges the surface. Then, an electrostatic latent image in which charging is attenuated is formed on the surface that has received a laser beam from an image writing unit 43 described later. The photosensitive layer is not particularly limited, but for example, amorphous silicon (a-Si) having excellent durability is preferable.

  The charging unit (charging charger) 42 charges the surface of the photosensitive drum 41 by discharging (for example, corona discharge). For example, the charging unit 42 has a thin wire or the like, and uses this as an electrode to discharge when a high voltage is applied. The image writing unit (LSU) 43 irradiates the photosensitive drum 41 with a light beam (for example, a laser beam) based on the image data, and forms an electrostatic latent image on the photosensitive drum 41. The image data is transmitted from a personal computer (PC) (not shown).

  The developing unit 21 forms toner images by attaching toner to the electrostatic latent image on the photosensitive drum 41. Examples of the developer stored in the developing unit 21 include a two-component developer composed of toner and a carrier and a one-component developer composed only of toner.

  The toner replenishing device 44 is detachably provided in the image forming apparatus 100. When the toner in the developing unit 21 becomes insufficient, the toner supplying device 44 supplies toner to the developing unit 21 and stores the toner. Is. Details of the toner supply device 44 will be described later. The toner supply device detection sensor 45 detects whether the toner supply device 44 is attached.

  The transfer unit 46 transfers the toner image formed on the surface of the photosensitive drum 41 to the sheet being conveyed without disturbing the toner image. The cleaning unit 47 removes toner (residual toner) remaining on the surface of the photosensitive drum 41 after the toner image is transferred (transferred) to the sheet. For example, a blade material that makes line contact with the longitudinal direction of the photosensitive drum 41 may be used. The sheet storage unit 51 stores a sheet (paper, OHP, etc.) on which an image (toner image) is finally printed, and sends the sheet to the transport unit 52.

  The conveyance unit 52 is a sheet path from the sheet storage unit 51 to the paper discharge unit 54, and the fixing unit 53 converts the toner image transferred onto the sheet into a stable permanent image, such as heat or pressure. By applying this energy, the toner image in the powder state is melted. The paper discharge unit 54 accommodates a sheet that has passed through the fixing unit 53, that is, a sheet on which a permanent image is printed.

  Then, the LSU 43 emits a laser beam (light beam) on the photosensitive drum 41 based on image data input in advance, thereby forming an electrostatic latent image based on the image data on the surface of the photosensitive drum 41. Thereafter, the developing unit 21 attaches toner to the electrostatic latent image (forms a toner image), and the transfer unit 46 transfers the toner image to the sheet. Next, the fixing unit 53 applies heat or the like to the sheet on which the toner image has been transferred to form a permanent image.

  7 is a schematic plan view of the toner replenishing device 44, FIG. 8 is a side cross-sectional view seen from the direction of arrow C in FIG. 7, and FIG. 9 is a perspective view of the toner replenishing device 44 seen from below. Here, a toner replenishing device that stores and supplies powder toner will be described. As shown in FIG. 7, the toner replenishing device 44 includes a casing (housing) 1, a stirring paddle 2, and a conveying screw 3. The casing 1 is a container for storing toner, and the stirring paddle 2 and the conveying screw 3 are disposed in parallel in the casing 1.

  The stirring paddle 2 has an arm portion 2b standing around a rotating shaft 2a, and a flat stirring plate 5 having a conveying sheet 4 whose tip can be bent in the rotation direction and a window portion through which toner passes. Are provided at the distal end of the arm portion 2b at positions alternately arranged in the axial direction, and are rotatably supported by the casing 1. Moreover, the arm part 2b is comprised by the some support | pillar 6, and the front-end | tip axis | shaft 7 fixed to the front-end | tip of the support | pillar 6 in parallel with the rotating shaft 2a.

  As the stirring paddle 2 rotates in the direction of arrow B in FIG. 7, the toner stored in the casing 1 is stirred and guided to the conveying screw 3. The conveying screw 3 has a configuration in which a spiral blade 3b is provided around the rotation shaft 3a, and a toner supply port provided on the bottom surface of the casing 1 shown in FIG. 9 by rotating in a predetermined direction. 8 supplies toner to the developing unit 21 (see FIG. 6).

  Next, driving of the stirring paddle 2 in the toner replenishing device 44 will be described. FIG. 10A is a schematic plan view showing a driving mechanism of the toner replenishing device 44, and FIG. 10B is a side view seen from the left side of FIG. For convenience of explanation, the description of the conveying screw 3 is omitted. A paddle input gear 9 for inputting a driving force to the stirring paddle 2 is fixed to one end of the rotating shaft (drive input shaft) 2a. Reference numeral 10 denotes a motor for rotationally driving the stirring paddle 2, and a motor drive shaft (drive output shaft) 10 a is connected to the paddle input gear 9 via a gear train including gears 11 and 12.

  In FIG. 10B, by rotating the motor drive shaft 10a in the direction of arrow A, the gears 11 and 12 rotate in the direction of the arrow, respectively, and the stirring paddle 2 also rotates in the direction of arrow B together with the paddle input gear 9, thereby moving the casing 1 The toner T inside is agitated. Since the stirring plate 5 is formed of a relatively hard material, the toner that can be stirred and transported is only within the effective range of the radius of rotation (the circle S in FIG. 8), but the transport sheet 4 is elastic. It is made of a strong material and is arranged to slide along the inner wall of the casing 1. As a result, even when the amount of toner in the casing 1 decreases, a sufficient amount of toner is supplied to the developing unit 21 (see FIG. 6) via the conveying screw 3 and the toner supply port 8 (see FIG. 9).

  In recent years, there has been a demand for further noise reduction in image forming apparatuses in order to meet the needs for improving the environment in offices. However, in the toner replenishing device as described above, since the conveyance sheet 4 rubs against the inner wall of the casing 1, there is a problem in that a rubbing sound is generated between the conveyance sheet 4 and the inner wall and noise during operation of the apparatus is increased. is there. The rubbing noise is absorbed and reduced by the toner when the amount of toner in the casing 1 is relatively large. However, as the amount of toner decreases, the rubbing sound leaks outside without being absorbed by the toner, resulting in unpleasant noise. .

  In view of this, there has been proposed a method for smoothly supplying toner to the developing unit and reducing the rubbing noise caused by the agitation paddle. For example, Patent Document 1 discloses a conveyance sheet that slides along the inner wall of the toner replenishing device. A method of providing a slidable member thinner than the conveying sheet at the tip is disclosed. Further, Patent Document 2 discloses a toner replenishing device in which a curved surface that smoothly connects the inner surface is formed at the connection portion between the top plate and the side wall of the toner replenishing device, and the front end of the conveying sheet is smoothly slid. Yes.

However, in the methods of Patent Documents 1 and 2, although the rubbing noise of the conveying sheet can be reduced to some extent, the conveying sheet is still slid in a state where it is pressed against the inner wall by the elastic force. It was not a sufficient method to completely suppress the occurrence.
Japanese Patent No. 3504909 Japanese Patent No. 3515049

  In view of the above problems, the present invention stabilizes toner agitation in the apparatus and toner supply to the developing unit, and reduces the generation of rubbing noise associated with toner agitation regardless of the amount of toner in the apparatus. An object is to provide a replenishing device.

  To achieve the above object, the present invention provides a casing for storing toner, a conveying screw for supplying toner stored in the casing to the developing unit, stirring of the toner stored in the casing, and the conveying screw. An agitation paddle for supplying to the rotation axis, and the agitation paddle includes a rotation shaft, and an arm portion having a distal end shaft parallel to the rotation shaft fixed to the distal ends of a plurality of support columns standing on the rotation shaft; In the toner replenishing device including the stirring member connected to the tip shaft, the stirring member includes a rod-like toner stirring unit having a specific gravity larger than that of the toner, and the toner stirring unit parallel to the tip shaft. In addition, the toner agitator is formed in a weight having a connecting portion that is rotatably connected, and the length of the toner agitating portion is shorter than the interval between the struts, and the turning radius of the agitating member is the rotation shaft It is characterized by shorter than the distance between said tip axis.

  According to the present invention, in the toner replenishing device configured as described above, the length of the connecting portion is set to a length such that the toner agitating portion contacts the bottom surface of the casing when the agitating paddle rotates, This is characterized in that when the stirring paddle is rotated, the length is set such that the tip shaft comes into contact with the closer one of the inner surfaces of the casing parallel to the rotation shaft.

  According to the present invention, in the toner replenishing device configured as described above, the bottom surface of the casing is a curved surface having substantially the same curvature as the locus of the toner stirring unit.

  According to the present invention, in the toner replenishing device configured as described above, the length of the toner stirring portion is longer than the interval between the spiral blades of the conveying screw.

  According to the present invention, in the toner replenishing device having the above-described configuration, the toner stirring portion is formed in a hook shape having a tip portion curved in a rotation direction of the stirring paddle.

  According to the present invention, in the toner replenishing device configured as described above, the connecting portion is formed of synthetic leather.

  According to the first configuration of the present invention, the stirring member includes a rod-shaped toner stirring portion having a specific gravity larger than that of the toner, and a connecting portion that rotatably connects the stirring rod in parallel to the distal end axis of the arm portion. When the stirring member is formed into a weight, a rubbing noise is not generated between the inner wall of the casing as in the case where the stirring member is a transport sheet, and the toner can be efficiently stirred and transported. Further, the length of the toner agitating portion is made shorter than the interval between the support columns, and the turning radius of the agitating member is made shorter than the interval between the rotating shaft and the tip shaft. Since it passes through the columns and returns to the original state, it is possible to avoid collision between the toner agitating unit and the columns or the rotating shaft, and to effectively prevent the generation of noise.

  According to the second configuration of the present invention, in the toner replenishing device of the first configuration, the length of the connecting portion is set such that the toner stirring portion abuts against the bottom surface of the casing when the stirring paddle rotates. The length of the column is such that when the stirring paddle rotates, the tip shaft reaches the closer side of the inner surface of the casing parallel to the stirring paddle, so that the bottom and inner surfaces of the casing using the weight-shaped stirring member are used. The nearby toner can be efficiently stirred.

  Further, according to the third configuration of the present invention, in the toner replenishing device of the second configuration, the bottom surface of the casing is a curved surface having substantially the same curvature as the locus of the toner stirring unit, so that the toner stirring unit is As the agitation paddle rotates, it smoothly moves along the inner surface of the casing. This further suppresses the generation of noise and improves the agitation and conveyance efficiency of the toner.

  According to the fourth configuration of the present invention, in the toner replenishing device having any one of the first to third configurations, the length of the toner stirring portion is made longer than the interval between the spiral blades of the conveying screw. This prevents the toner agitating portion from entering between the spiral blades of the conveying screw and being sandwiched between the casing and the conveying screw when the agitating paddle is rotated, thereby preventing the agitating paddle and the conveying screw from being damaged.

  According to the fifth configuration of the present invention, in the toner replenishing device having any one of the first to fourth configurations, the tip of the toner stirring unit is formed in a hook shape curved in the rotation direction of the stirring paddle. By doing so, the toner at the bottom of the casing can be more efficiently stirred and conveyed.

  According to the sixth configuration of the present invention, in the toner replenishing device having any one of the first to fifth configurations, the connecting portion is formed of synthetic leather having excellent slidability and wear resistance. In addition, the stirring and transport of the toner by the stirring member can be performed more smoothly, and the life of the stirring member can be extended.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a side sectional view showing a toner replenishing device according to a first embodiment of the present invention. Portions common to FIG. 8 of the conventional example are denoted by the same reference numerals and description thereof is omitted. In FIG. 1, the tip shaft 7 of the arm portion 2 b has a weight-like shape composed of a rod-shaped toner stirring portion 13 extending in the paper direction of the drawing and a connecting portion 14 that connects the toner stirring portion 13 to the tip shaft 7. The stirring member 15 is connected.

  FIG. 2 is a perspective view of a stirring paddle used in the toner replenishing device of the first embodiment. As shown in FIG. 2, the connecting portion 14 is formed in a sheet shape, the toner stirring portion 13 is included and fixed at one end, the tip shaft 7 is included at the other end, and the connecting portion is connected at the adhesive portion 16. 14 are bonded together to form a loop portion 14a. Accordingly, the loop portion 14 a can slide around the tip shaft 7, and the toner stirring portion 13 is connected to the tip shaft 7 via the connecting portion 14 so as to be rotatable in parallel.

  The present embodiment is characterized in that a weight-like stirring member 15 is attached to the tip shaft 7 instead of the transport sheet 4 (see FIG. 8). With this configuration, unpleasant rubbing noise does not occur unlike the conveyance sheet 4 that stirs and conveys the toner while rubbing the inner wall surface of the casing 1. Further, since the toner stored in the bottom portion of the casing 1 beyond the effective range of the rotation radius of the arm portion 2b can be effectively stirred, the toner can be effectively used.

  Further, the length of the connecting portion 14 is preferably set to a length where the toner stirring portion 13 is in contact with the bottom surface of the casing 1 in a state where the arm portion 2b is vertically downward. When the connecting portion 14 is shorter than this length, the toner near the bottom of the casing 1 cannot be sufficiently stirred. When the connecting portion 14 is longer than this length, the toner stirring portion 13 collides with the casing 1 to generate noise. Cause.

  The material of the connecting portion 14 is not particularly limited, and various materials such as synthetic resin and metal can be used. However, in order to suppress the generation of noise accompanying the rotation of the stirring paddle 2 as much as possible, the material is soft and elastic. It is preferable to use synthetic leather that is also excellent in slidability and wear resistance.

  Further, the length L of the toner stirring portion 13 is shorter than the interval between the two support columns 6, and the rotation radius R of the stirring member 15 (the distance from the tip shaft 7 to the toner stirring portion 13) is the rotation shaft 2a. And the tip shaft 7 are set to be shorter than the distance between them. As a result, the toner agitation unit 13 can rotate around the rotation shaft 2a without colliding with the support column 6 and the rotation shaft 2a, and the agitation member 15 passes through the support column 6 even when the agitation paddle 2 rotates. Therefore, the toner can be smoothly stirred.

  The toner agitation unit 13 is formed of a material having a specific gravity greater than that of the toner stored in the casing 1 (see FIG. 1). The specific gravity of the toner is about 1.1 to 1.4 for non-magnetic toner and about 1.7 for magnetic toner. Therefore, it is made of a material having a specific gravity larger than this, for example, a metal such as aluminum, iron, copper, or lead. If there is, the toner agitation unit 13 sinks into the toner and can be agitated. Among them, by using a metal having a high specific gravity such as iron with a specific gravity of 7.9, copper of 8.9, and lead of 11.4. As the stirring paddle 2 rotates, the toner stirring unit 13 sinks deeply into the toner, and the toner near the bottom of the casing 1 can be sufficiently stirred.

  In this embodiment, the sheet-like connecting portion 14 is used, but both ends of the toner stirring portion 13 may be connected to the tip shaft 7 using, for example, a string-like connecting portion 14 as shown in FIG. . In this case, as compared with the case where the sheet-like connecting portion 14 is used, the stirring resistance that the connecting portion 14 receives from the toner is reduced.

  Here, although two support columns 6 constituting the arm portion 2 b are provided at both ends of the rotating shaft 2 a, three or more support columns 6 may be provided according to the length of the stirring paddle 2. In that case, a plurality of stirring members 15 may be connected between the support columns 6, and the toner stirring unit 13 may be set shorter than the interval between the support columns 6. When the length of the toner stirring unit 13 is shorter than the interval between the spiral blades 3b (see FIG. 7) of the conveying screw 3, the toner stirring unit 13 enters the interval between the spiral blades 3b when the stirring paddle 2 rotates. If the stirring paddle 2 continues to rotate in this state, the stirring paddle 2 or the conveying screw 3 may be damaged. Therefore, it is preferable that the length of the toner stirring unit 13 is longer than the interval between the spiral blades 3b.

  In the toner replenishing device of the first embodiment, the manner in which the toner is stirred and conveyed by the rotation of the stirring paddle 2 will be described with reference to FIG. When the stirring paddle 2 rotates counterclockwise (arrow D direction) from the state of FIG. 1, the toner stirring portion 13 of the stirring member 15 also descends along the inner side surface 1a of the casing 1, and the toner near the bottom surface is removed. Move in the direction of arrow D while pressing. FIG. 4A shows a state in which the stirring paddle 2 is rotated about 90 °, and the arm portion 2b is positioned substantially vertically downward. The length of the connecting portion 14 is set so that the toner stirring portion 13 is in contact with the bottom surface 1b in the state of FIG.

  When the stirring paddle 2 further rotates in the direction of arrow D from the state of FIG. 4A, the toner stirring unit 13 rises along the curvature of the bottom surface 1b of the casing 1, and the toner stirring unit 13 moves along the bottom surface 1b. The toner pushed in the direction of arrow D is conveyed onto the conveying screw 3 and further supplied to the developing unit 21 (see FIG. 6) from the toner supply port 8 (see FIG. 9) provided on the bottom surface 1b. FIG. 4B shows a state where the stirring paddle 2 is rotated about 90 ° from FIG.

  When the stirring paddle 2 further rotates 90 ° in the direction of arrow D from the state shown in FIG. 4B, the arm portion 2b gradually rises upward, and the toner stirring portion 13 also moves away from the bottom surface 1b and rises in the vicinity of the conveying screw 3. To do. FIG. 4 (c) shows a state rotated about 90 ° from FIG. 4 (b). At this time, the arm portion 2b is positioned substantially vertically upward. Then, when further rotating in the direction of arrow D from the state of FIG. 4C, the stirring member 15 passes between the two columns 6 and moves to the left side in the drawing, and returns to the state of FIG.

  As is apparent from FIG. 4, the locus of the toner stirring portion 13 is a circle having the same radius as that of the arm portion 2b. Therefore, as in the present embodiment, the bottom surface 1b of the casing 1 is a curved surface, so that the toner agitating unit 13 moves smoothly along the inner wall surface of the casing 1, and the toner is efficiently generated while suppressing the generation of noise. Stirring is possible. Furthermore, it is more preferable that the curvature of the bottom surface 1b is substantially the same as the locus of the toner stirring unit 13 because the movement of the toner stirring unit 13 becomes smoother.

  FIG. 5 is a side sectional view showing the toner replenishing device according to the second embodiment of the present invention. Portions common to FIG. 1 are denoted by the same reference numerals and description thereof is omitted. In the present embodiment, the tip of the flat-plate toner stirring portion 13 is curved in a hook shape in the rotation direction of the stirring paddle 2. The structure of other parts is the same as that of the first embodiment.

  By adopting the configuration of the present embodiment, the toner near the bottom surface of the casing 1 can be scraped up without being left by the toner stirring unit 13 and can be efficiently conveyed onto the conveying screw 3, and the amount of toner remaining in the casing 1 can also be increased. Therefore, the toner can be used more effectively. The materials and lengths of the toner agitation unit 13 and the coupling unit 14 constituting the agitation member 15 and the manner in which the agitation member 15 rotates with the rotation of the agitation paddle 2 are the same as in the first embodiment, and thus will be described. Is omitted.

  In addition, this invention is not limited to the said embodiment, A various change is possible in the range which does not deviate from the meaning of this invention. For example, in each of the above embodiments, the toner agitating unit 13 is rotatably connected to the tip shaft 7 by including the tip shaft 7 with the loop portion 14 a formed at one end of the connecting portion 14. One end of 14 may be fixed to the tip shaft 7, and the tip shaft 7 may be rotatably supported by the column 6.

  Further, here, the stirring paddle 2 in which only the weight-like stirring member 15 is connected to the arm portion 2b has been described, but another stirring member, for example, a window portion through which toner passes as shown in FIG. 7 is formed. By mounting the flat plate-like stirring plate 5 on the arm portion 2b together with the weight-like stirring member 15, the toner can be stirred and conveyed more effectively without generating unpleasant noise.

  The present invention includes a casing for storing toner, a conveying screw that supplies toner stored in the casing to the developing unit, and an agitation paddle that performs stirring of the toner stored in the casing and supply to the conveying screw. An agitation paddle comprising: a rotating shaft; an arm portion in which a tip shaft parallel to the rotating shaft is fixed to the tips of a plurality of support columns erected on the rotating shaft; and a stirring member connected to the tip shaft In the toner replenishing device configured, the stirring member has a weight-like shape composed of a rod-shaped toner stirring portion having a specific gravity larger than that of the toner and a connecting portion that rotatably connects the toner stirring portion in parallel to the tip shaft. The length of the toner stirring portion is shorter than the interval between the support columns, and the rotation radius of the stirring member is shorter than the interval between the rotating shaft and the tip shaft.

  As a result, a toner replenishing device having a simple configuration that does not generate noise such as rubbing noise when the stirring paddle is rotated and can efficiently stir and convey toner can be provided at low cost. Further, since the length of the toner agitating portion is made shorter than the interval between the support columns, and the turning radius of the agitating member is made shorter than the interval between the rotating shaft and the tip shaft, the toner agitating portion passes between the support columns and returns to the original position. Returning to the state, the toner agitating unit and the support column or the toner agitating unit and the rotating shaft are effectively prevented from colliding with each other to smoothly agitate and convey the toner.

  Further, the length of the connecting portion is set so that the toner stirring portion contacts the bottom surface of the casing when the stirring paddle rotates, and the length of the support column is set so that the tip shaft contacts the inner surface of the casing when the stirring paddle rotates. Since the length is set, a toner replenishing device that prevents generation of noise and insufficient stirring and efficiently stirs toner near the bottom of the casing and the inner wall surface by using a weight-like stirring member and a tip shaft.

  Further, if the bottom surface of the casing is a curved surface having substantially the same curvature as the locus of the toner agitating portion, the toner agitating portion can move smoothly along the inner surface of the casing, further suppressing noise generation and toner The agitation and conveyance efficiency are also improved.

  In addition, since the length of the toner agitating portion is longer than the interval between the spiral blades of the conveying screw, the toner agitating portion enters between the spiral blades of the conveying screw when the agitating paddle is rotated, and between the casing and the conveying screw. Therefore, the toner replenishing device is not likely to be pinched.

  Also, if the tip of the toner stirring part is bent in the rotation direction of the stirring paddle and formed into a hook shape, the toner near the bottom surface of the casing can be scraped up and efficiently stirred and conveyed, Since the amount of toner remaining in the casing is also reduced, the toner replenishing device can use the toner more effectively.

  In addition, since the connecting part is made of synthetic leather with excellent slidability and wear resistance, the stirring member can be more smoothly stirred and transported, and the life of the stirring member can be extended and the running time of the toner replenishing device can be reduced. Contributes to cost reduction.

FIG. 2 is a side cross-sectional view showing the toner supply device of the first embodiment of the present invention. FIG. 2 is a perspective view showing a configuration of a stirring paddle used in the toner supply device of the first embodiment. FIG. 10 is a perspective view showing another example of a stirring paddle. These are side surface sectional drawings which show the state which the stirring paddle of the toner replenishing apparatus of 1st Embodiment rotates. These are side surface sectional drawings which show the toner supply apparatus of 2nd Embodiment of this invention. FIG. 1 is a schematic diagram illustrating an overall configuration of a conventional image forming apparatus. FIG. 3 is a plan view of a conventional toner replenishing device. FIG. 3 is a side sectional view of a conventional toner replenishing device. FIG. 3 is a perspective view of a conventional toner replenishing device viewed from below. These are the top view and side view which show the drive mechanism of the conventional toner replenishing apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Casing 1a Inner side surface 1b Bottom surface 2 Stirring paddle 2a Rotating shaft 2b Arm part 3 Conveying screw 3a Rotating shaft 3b Spiral blade 4 Conveying sheet 5 Stirring plate 6 Strut 7 Tip shaft 13 Toner agitating part 14 Connecting part 15 Stirring member 44 Toner supply device 100 Image forming apparatus

Claims (6)

A casing for storing toner;
A conveying screw for supplying toner stored in the casing to the developing unit;
A stirring paddle for stirring the toner stored in the casing and supplying the toner to the conveying screw;
The stirring paddle includes a rotating shaft, an arm portion in which tip ends parallel to the rotating shaft are fixed to tips of a plurality of support columns standing on the rotating shaft, and a stirring member connected to the tip shaft. In a toner replenishing device comprising:
The stirring member is formed in a weight-like shape including a rod-shaped toner stirring portion having a specific gravity larger than that of the toner and a connecting portion that connects the toner stirring portion in parallel to the tip shaft and is rotatable. The toner replenishing device, wherein a length of the toner agitating portion is shorter than an interval between the support columns, and a turning radius of the agitating member is shorter than an interval between the rotating shaft and the tip shaft.   The length of the connecting portion is set to a length such that the toner stirring portion contacts the bottom surface of the casing when the stirring paddle rotates, and the length of the support column is the rotation shaft when the stirring paddle rotates. 2. The toner replenishing device according to claim 1, wherein the toner replenishing device is set to a length such that the tip shaft comes into contact with a closer side of an inner side surface of the casing parallel to the surface of the casing.   The toner replenishing device according to claim 2, wherein a bottom surface of the casing is a curved surface having substantially the same curvature as a locus of the toner stirring unit.   4. The toner replenishing device according to claim 1, wherein a length of the toner stirring unit is longer than an interval between spiral blades of the conveying screw.   The toner replenishing device according to any one of claims 1 to 4, wherein the toner agitating portion is formed in a hook shape having a tip portion curved in a rotating direction of the agitating paddle.   The toner replenishing device according to claim 1, wherein the connecting portion is made of synthetic leather.

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