JP2004133225A - Developing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a new and improved developing apparatus capable of avoiding a pressure against toner and capable of appropriately replenishing the toner from a toner container 6 to a developing chamber 14 in accordance with the reduction of the toner in the developing chamber 14. <P>SOLUTION: The developing apparatus 2 is provided with a housing 8 equipped with the developing chamber 14, a stirring/carrying means 28 arranged in the developing chamber 14 and the toner container 6. The developing chamber 14 is provided with first and second carrying paths 26a and 26b and communication paths 27a and 27b. A toner receiving port 83 is formed in the developing chamber 14 so as to be positioned in the upper part of a toner receiving area. A toner discharge port 62 is formed in the toner container 6. A projecting area 82 is arranged in the housing 8 so as to be adjacent to the outside of the first carrying path 26a and also communicate with the first carrying path 26a. The toner receiving area is set in the projecting area 82. The carrying capacity of the stirring/carrying means 28 is reduced on the downstream side of the area adjacent to the toner receiving area. An auxiliary rotating helical blade member 90 is arranged in the projecting area 82. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a developing device for developing an electrostatic latent image into a toner image used in an electrostatic image forming machine such as an electrostatic printer, a copying machine and a facsimile, and more specifically, a toner container or a toner hopper. A toner discharge opening positioned substantially above and opposite to the toner receiving opening so as to communicate with the toner receiving opening when toner can be supplied into the developing chamber. And a developing device.
[0002]
[Prior art]
The developing device of the above-described embodiment has been developed by the present applicant, Kyocera Mita Corporation, and has already been filed (see Patent Document 1). The developing device disclosed in Patent Document 1 includes a housing having a developing chamber that defines a toner circulation path, a stirring and conveying unit disposed in the development chamber for conveying the toner through the circulation path while stirring the toner, The image forming apparatus includes a toner application unit for applying the toner in the developing chamber to an electrostatic latent image to be developed, and a toner container detachably mounted on a housing for supplying toner to the developing chamber. The developing chamber has a toner receiving opening located above the toner receiving area in the circulation path. The toner container includes a toner container case containing toner. The toner container case has a toner discharge opening that is located above and opposed to the toner receiving opening when the toner container is mounted on the housing. The toner container includes a toner conveying unit that conveys the toner stored in the toner container case toward the toner discharge opening. The transport capacity of the stirring transport unit provided in the developing chamber is locally reduced on the downstream side of the toner receiving area.
[0003]
In the above-mentioned developing device, the conveying capacity of the stirring and conveying means for conveying the toner through the circulation path defined in the developing chamber while stirring the toner is located on the downstream side of the toner receiving area where the toner receiving opening is disposed above. Because of the local reduction, toner stagnation is generated in the toner receiving area. Such an amount of staying toner fluctuates according to the amount of toner in the developing chamber. The replenishment of toner from the toner container to the developing chamber does not depend directly on the drive control of the toner conveying means of the toner container, but is automatically performed in accordance with the amount of accumulated toner in the toner receiving area, and therefore in accordance with the amount of toner in the developing chamber. Is controlled.
[0004]
[Patent Document 1]
JP 2001-235933 A (Claims 1 to 3, FIGS. 3 and 4)
[0005]
[Problems to be solved by the invention]
In the above-described conventional developing device, the amount of toner supplied to the developing chamber is controlled by controlling the driving of the toner conveying means of the toner container based on a detection signal from a toner amount detection sensor provided in the developing chamber. Need not be controlled, a dedicated driving source for driving the sensor and the toner conveying means of the toner container is not required. Therefore, although the manufacturing cost can be reduced, the toner in the developing chamber is reduced. Therefore, it is possible to appropriately supply the toner from the toner container to the developing chamber in accordance with the above-mentioned condition. However, on the other hand, in the toner receiving area, the pulsation and vibration accompanying the rotation of the stirring and conveying means are easily transmitted to the toner above the stirring and conveying means, and the toner is excessively pressed together with the toner supply pressure from the toner container. As a result, aggregation or blocking of the toner may be generated, and smooth flow of the toner may be hindered.
[0006]
SUMMARY OF THE INVENTION An object of the present invention is to avoid an excessive pressure of toner in a toner receiving area, and to eliminate the need for a dedicated driving source for driving a toner conveying unit in a toner replenishing unit such as a toner container or a toner hopper. Therefore, a new and improved developing apparatus which can appropriately supply toner from the toner replenishing means to the developing chamber in accordance with a decrease in the toner in the developing chamber, although the manufacturing cost can be sufficiently reduced. It is to provide.
[0007]
[Means for Solving the Problems]
According to one aspect of the present invention, a housing having a developing chamber that defines a toner conveying path, a stirring and conveying unit disposed in the developing chamber for conveying the toner through the conveying path while stirring, and a developing chamber Toner applying means for applying the toner to the electrostatic latent image to be developed, and toner replenishing means for replenishing the toner into the developing chamber, wherein the housing has a toner receiving opening located above the toner receiving area. The toner replenishing means is provided with a toner discharge opening substantially above the toner receiving opening and opposed to the toner receiving opening so as to communicate with the toner receiving opening when the toner can be supplied into the developing chamber. Is formed in the developing device,
In the housing, a protruding area adjacent to the outside of the conveying path and communicated with the conveying path is provided, the toner receiving area is set in the protruding area, and the conveying capacity of the stirring conveying means is in the toner conveying path, Auxiliary agitating and conveying means for discharging the toner to the conveying path while agitating the received toner is provided in the protruding area, which is reduced on the downstream side of the area adjacent to the toner receiving area.
A developing device is provided.
According to another aspect of the present invention, a housing having a developing chamber that defines a toner circulation path, a stirring and conveying unit disposed in the development chamber for conveying the toner through the circulation path while stirring the toner, A toner applying unit for applying the toner in the chamber to the electrostatic latent image to be developed; and a toner replenishing unit for replenishing the toner in the developing chamber, wherein the circulation path extends in parallel with the toner applying unit. A first transport path, a second transport path extending along the first transport path and the toner applying unit, and a region between both end areas of the first and second transport paths are communicated with each other. A communication passage, wherein the housing has a toner receiving opening located above the toner receiving area, and the toner replenishing means substantially communicates with the toner receiving opening when toner can be supplied into the developing chamber. To In the developing device having the toner discharge opening is formed which is located above the toner receiving opening opposite the over receiving opening,
The housing is provided with a projecting area adjacent to the outside of the first conveying path and communicated with the first conveying path, the toner receiving area is set in the projecting area, and the conveying capacity of the stirring conveying means is: In the first conveyance path, the amount is reduced on the downstream side of the area adjacent to the toner receiving area, and in the protruding area, an auxiliary stirring conveyance means for discharging the received toner to the conveyance path while stirring is provided. ing,
A developing device is provided.
The housing includes an end wall that defines the outside of the first conveyance path, and the end wall extends along a position near the outside of the stirring and conveyance means disposed in the first conveyance path along the stirring and conveyance means. And a pair of protruding regions protruding outward from the outer proximate region. The protruding region includes a pair of protruding walls in the first conveying path that are opposed to each other at an interval in a toner conveying direction. It is preferable that an auxiliary agitating / conveying means is rotatably supported between the pair of projecting walls, the projecting outer wall and the projecting bottom wall extending between the projecting walls.
It is preferable that the entire area in the toner conveyance direction in the protruding area communicates with the first conveyance path.
It is preferable that only the downstream area in the toner transport direction in the protruding area communicates with the first transport path.
Preferably, the protruding region extends further upstream from the upstream end of the housing in the toner conveying direction in the first conveying path.
The auxiliary stirring and conveying means is an auxiliary rotating spiral blade member including a central shaft portion and a spiral blade, or an auxiliary rotating stirring plate member including a central shaft portion and a stirring plate, or an auxiliary rotation including a central shaft portion, a spiral blade, and a stirring plate. It is preferable that it is composed of a spiral blade and a stirring plate member.
The toner supply means is a toner container detachably mounted on the housing.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, preferred embodiments of a developing device configured according to the present invention will be described in more detail with reference to the accompanying drawings.
[0009]
1 and 2 show a preferred embodiment of a developing device constituted according to the present invention. The illustrated developing device, generally designated by reference numeral 2, comprises a developing device main body 4, a toner replenishing means, and a toner container 6 in the embodiment.
[0010]
The developing device main body 4 includes a housing 8, and the housing 8 includes a housing main body 10 and an upper wall member 12 mounted on the housing main body 10. In the left half of FIG. 1 of the housing body 10 which can be molded from an appropriate synthetic resin, a developing chamber 14 having an open upper surface (more specifically, a main portion excluding a left edge) and a left side surface is provided. Stipulated. The housing body 10 has a bottom wall 16, side walls 18 and 20, and a connecting wall 22. The connecting wall 22 extends between the upper edges of the left and right side walls 18 and 20 in FIG. The bottom wall 16 of the housing body 10 has three arc-shaped portions 16a, 16b, and 16c arranged in parallel and having a circular cross-sectional shape. A partition 24 extending substantially vertically upward is formed between the arc portion 16a and the arc portion 16b. On both sides of the partition 24, the first transport path 26a and the second transport path 26a, which are linear paths, are respectively provided. The transport path 26b is defined. Both ends of the partition 24 are separated from the inner surfaces of the side walls 18 and 20 of the housing body 10, and a required gap exists between both ends of the partition 24 and the inner surfaces of the side walls 18 and 20.
[0011]
A gap between one end (the right end in FIG. 2) of the partition wall 24 and the side wall 18 is a communication path that communicates with one end area (the right end area in FIG. 2) of each of the first transport path 26a and the second transport path 26b. 27a, and a gap between the other end (the left end in FIG. 2) of the partition wall 24 and the side wall 20 is formed in the other end region (FIG. 2) of each of the first transport path 26a and the second transport path 26b. At the left end area). Therefore, the first transport path 26a and the second transport path 26b extending in parallel with each other are communicated with each other via the communication paths 27a and 27b at both end regions, and thus the first transport path 26a , And then from the one end area of the first conveyance path 26a to the one end area of the second conveyance path 26b via the communication path 27a, extend along the second conveyance path 26b, and An endless circulation path extending from the other end area of the path 26b to the other end area of the first transport path 26a is defined (the toner is circulated through the circulation path as will be further described later). In other words, the circulation path is formed by a first conveyance path 26a extending in parallel with the toner application unit 40 described later, and a first conveyance path 26a between the first conveyance path 26a and the toner application unit 40. A second conveying path 26b extending along the toner applying means 40; and communication paths 27a and 27b communicating between both end areas of the first conveying path 26a and the second conveying path 26b. .
[0012]
In the circulation path described above, which constitutes a conveyance path through which the toner is conveyed, a stirring and conveying means 28 for conveying the toner through the circulation path while stirring the toner is provided. The stirring and conveying means 28 in the illustrated embodiment is a first stirring and conveying means disposed on the first conveying path 26a and extending along the first conveying path 26a, and in the embodiment, a first rotating spiral. A blade member 30a and a second stirring / transporting means disposed in the second transport path 26b and extending along the second transport path 26b, and in the embodiment, a second rotary spiral blade member 30b. Have been. The first rotating spiral blade member 30a, which can be molded from an appropriate synthetic resin, has a central shaft portion 32a and a spiral blade 34a. Similarly, the second rotary spiral blade member 30b, which can be molded from an appropriate synthetic resin, also has a central shaft portion 32b and a spiral blade 34b. The first rotary spiral blade member 30a is rotatably mounted between the side walls 18 and 20 of the housing body 10, and extends linearly along the first transport path 26a. The second rotary spiral blade member 30b is also rotatably mounted between the side walls 18 and 20 of the housing body 10, and extends linearly along the second transport path 26b. One end (right end in FIG. 2) of the central shaft portion 32a of the first rotary spiral blade member 30a and one end (right end in FIG. 2) of the central shaft portion 32b of the second rotary spiral blade member 30b are side walls 18. The input gears 32c and 32d are fixed to these protruding ends, respectively. When the developing device 2 is mounted at a predetermined position of the image forming machine, the input gear 32c of the first rotary spiral blade member 30a and the input gear 32d of the second rotary spiral blade member 30b mesh with a transmission gear (not shown). And a drive connection (not shown), which may be an electric motor. When a driving source (not shown) is energized, the first rotating spiral blade member 30a and the second rotating spiral blade member 30b respectively have the same rotational speed R1 in the same direction indicated by an arrow 36 in FIGS. (R.p.m.) and R2 (r.p.m.).
[0013]
As can be clearly understood by referring to FIG. 2, the spiral blades 34a of the first rotating spiral blade member 30a and the spiral blades 34b of the second rotating spiral blade member 30b have so-called spiral directions set in opposite directions. By rotating the first spiral blade member 30a in the direction indicated by the arrow 36, the toner is transported in the direction indicated by the arrow 37 through the first transport path 26a, and the second rotary spiral blade member 30b is rotated. By being rotated in the direction indicated by the arrow 36, the toner is conveyed in the direction indicated by the arrow 38 through the second conveyance path 26b.
[0014]
The housing 8 has a toner receiving opening 83 formed above the toner receiving area. The housing 8 also has a protruding region 82 adjacent to the outside of the first conveyance path 26a (outside on the side opposite to the side facing the second conveyance path 26b) and communicated with the first conveyance path 26a. Is established. The toner receiving area is set in the protruding area 82, and in the protruding area 82, an auxiliary stirring and conveying unit that discharges the received (supplied) toner to the first conveying path 26a while stirring the toner. It is important that the rotary spiral blade member 90 is provided. More specifically, the housing 8 includes an end wall 80 that defines the outside of the first transport path 26a. The end wall 80 extends along the first rotary spiral blade member 30a at a position near the outside of the first rotary spiral blade member 30a as the first stirring and transporting means disposed in the first transport path 26a. And a projecting region 82 projecting outward from the outside neighboring region 81. The protruding area 82 includes a pair of protruding walls 82a opposed to each other at an interval in the toner conveying direction in the first conveying path 26a, a protruding outer wall 82b and a protruding bottom wall 82c extending between the pair of protruding walls 82a. It has. The protruding outer wall 82b extends substantially vertically when the housing 8 is viewed in the width direction (the direction perpendicular to the paper surface in FIG. 1), and the protruding bottom wall 82c is formed on the first transport path 26a with respect to the horizontal plane when viewed in the same width direction. From the outside (right side in FIG. 1) toward the first transport path 26a, and further downward toward the arcuate portion 16a of the bottom wall 16. The upper end surface of each protruding wall 82a is defined by an arc-shaped portion that protrudes downward. The toner receiving area is set in the projecting area 82, and the toner receiving opening 83 is formed by the upper edge of the projecting area 82. In the embodiment, between the upper edges of the pair of projecting walls 82a constituting the projecting region 82, the upper edges of the projecting outer walls 82b, and a central region 53a of the flange 53 of the upper surface wall 50, which will be described later. A toner receiving opening 83 which opens upward outside the first transport path 26a is formed. The toner receiving opening 83 communicates with the first transport path 26a through a gap formed between the pair of projecting walls 82a, the lower end surface of the central region 53a of the flange 53, and the lower end of the projecting bottom wall 82c. I have. Therefore, in the illustrated embodiment, the entire area of the protruding area 82 in the toner conveyance direction is communicated with the first conveyance path 26a. The toner is introduced into the toner receiving area through the toner receiving opening 83. The toner receiving opening 83 may be configured to cover a part of an upper surface wall 50 to be described later to cover an upper end portion of the protruding region 82, or a cover member (not shown) provided so as to detachably cover the protruding region 82. May be formed. In the above embodiment,
Since the protruding region 82 forms a part of the developing chamber 14, it can be said that the developing chamber 14 has a toner receiving opening 83 located above the toner receiving area.
[0015]
The auxiliary rotary spiral blade member 90 that can be molded from an appropriate synthetic resin has a central shaft portion 91 and a spiral blade 92. Both ends of the central shaft portion 91 of the auxiliary rotary spiral blade member 90 are rotatably supported by a pair of protruding walls 82 a forming a protruding region 82. One end of the central shaft portion 91 projects outward from one of the projecting walls 82a, and an input gear (not shown) is fixed to the projecting end of the central shaft portion 91. The input gear of the central shaft portion 91 is meshed with the input gear 32c of the first rotary spiral blade member 30a via a transmission gear (not shown). When the developing device 2 is mounted at a predetermined position of the image forming machine, the input gear of the auxiliary rotary spiral blade member 90 uses a power transmission mechanism such as a transmission gear (not shown) and an input gear 32c of the first rotary spiral blade member 30a. The driving source is connected to the driving source described above via the driving source. When this drive source is energized, the auxiliary rotary spiral blade member 90 is driven to rotate in the direction indicated by the arrow 93 in FIGS. 1 and 2. When the auxiliary rotary spiral blade member 90 is driven to rotate in the direction shown by the arrow 93, the toner present in the projecting area 82 is transported along the projecting area 82 in the direction shown by the arrow 94 in FIG. It is discharged toward the transport path 26a.
[0016]
In the present invention, the toner conveying capacity of the stirring and conveying means 28 is reduced in the toner conveying path, in the embodiment, on the first conveying path 26a, on the downstream side of the area adjacent to the toner receiving area. . In the embodiment illustrated in FIG. 2, in a specific region indicated by reference numeral 47, the outer diameter D1a of the spiral blade 34a in the first rotating spiral blade member 30a is locally larger than the outer diameter D1b in the other region. In the specific area 47, the transport capacity of the toner stirring and transporting means 28 is locally reduced. The outer diameter D1b of the spiral blade 34a in a region other than the specific region 47 of the first rotating spiral blade member 30a and the outer diameter D2 of the spiral blade 34b in the entire second rotating spiral blade member 30b are set to be substantially the same. The diameter r1 of the central shaft portion 32a of the first rotary spiral blade member 30a and the diameter r2 of the central shaft portion 32b of the second rotary spiral blade member 30b are set substantially the same. The pitch P1 of the spiral blades 34a of the first rotary spiral blade member 30a and the pitch P2 of the spiral blades 34b of the second rotary spiral blade member 30b are substantially the same. Therefore, the conveying capacity (per unit pitch) of the toner stirring and conveying means 28 in the area other than the specific area 47 is substantially the same. In order to locally reduce the transport capacity in the specific area 47, instead of reducing only the outer diameter D1a of the spiral blade 34a, for example, the spiral diameter 34a and the outer diameter D1a of the spiral blade 34a are set smaller. It is also possible to set only the pitch P1 of the blades 34a small, form a notch in the spiral blades 34a, set only the diameter r1 of the central shaft portion 32a large, or omit the spiral blades 34a. The specific area 47 in which the transport capacity is locally reduced is located downstream of an area adjacent to the toner receiving area where the toner is introduced into the developing chamber 14 through the toner receiving opening 83.
[0017]
Above the arc-shaped portion 16c of the bottom wall 6 of the housing body 10, a toner applying unit 40 is disposed. The toner applying means 40 includes a developing sleeve 41 rotatably mounted between the side walls 18 and 20 of the housing body 10. In the developing sleeve 41, a stationary permanent magnet (not shown) is arranged. One end of the rotating shaft 42 to which the developing sleeve 41 is fixed projects through the side wall 18 and an input gear 43 is fixed to the projecting end. When the developing device 2 is mounted at a predetermined position of the image forming machine, the input gear 43 is meshed with one of transmission gears (not shown) and is drivingly connected to a drive source (not shown) which may be an electric motor. This drive source is a drive source common to the drive sources of the first and second rotary spiral blade members 30a and 30b. Therefore, when this driving source is energized, the developing sleeve 41 is rotated in the direction indicated by the arrow 39. An ear cutting means 44 is provided in association with the developing sleeve 41. In the developing chamber 14, a one-component developer composed of only toner is stored, and the developer, that is, the toner, is rotated in a direction indicated by an arrow 36 in a first rotating spiral blade member 30a and a second rotating spiral blade member. By the operation of 30b, the sheet is circulated and conveyed through the circulation path. The toner applying unit 40 holds the toner on the peripheral surface of the developing sleeve 41 rotated in the direction indicated by the arrow 39, and conveys the toner through the developing area 45. The ear cutting means 44 regulates the layer thickness of the toner held on the peripheral surface of the developing sleeve 41 and conveyed to the developing area 45. In the development zone 45, the toner is applied to the electrostatic latent image to be developed, thus developing the electrostatic latent image into a toner image.
[0018]
The upper wall member 12 is mounted on the housing body 10. The upper wall member 12 has an upper wall 50 that covers the upper surface of the developing chamber 14. A flange portion extending downward is formed on the periphery of the upper surface wall 50. Of these, the lower end surfaces of a pair of flange portions 51 (only one flange portion 51 is shown in FIG. 1) facing in the width direction (the direction perpendicular to the paper surface in FIG. 1) are formed by the side walls 18 and 20. It is placed on the upper end face via a sealing member (not shown). The lower end surface of one (left side in FIG. 1) flange portion 52 of the pair of flange portions facing each other in the direction orthogonal to the width direction is placed on the upper surface of the connection wall 22 via a sealing member (not shown). The two end regions on the lower end surface of the other (rightward in FIG. 1) flange portion 53 are placed on the upper end surface of the outer vicinity region 81 of the end wall 80 via a sealing member (not shown). The central region 53a of the flange 53 extends downward between the pair of protruding walls 82a of the protruding region 82 in the end wall 80. A required gap is formed between the central region 53a, the upper edge of the pair of projecting walls 82a, and the upper edge of the projecting outer wall 82b of the end wall 80. As shown in FIG. 2, the gap, which is substantially rectangular in a plane, is opened upward. The central area 53a forms a partition wall that partitions the first transport path 26a and an upper area in the protruding area 82. This partition wall may be formed by extending a part of the upper region in the region 81 outside the end wall 80. The gap (having a rectangular shape) between the lower end surface of the central region 53a, the bottom wall 16, and the surface facing each other in the outer vicinity region 81 of the end wall 80 is defined by the first transport path 26a and the protruding region. A communication port that communicates with the communication port 82 is formed. When the toner discharge opening 62 of the toner container 6 is disposed close to the upper surface of the retained toner in the toner receiving area, the outer peripheral area of the partition wall or the end wall 80 formed by the central area 53a is provided. It is not necessary to provide a partition wall formed by extending a part of the upper region in the region 81. The lower end surface of the central region 53a is filled with a predetermined amount of toner in the developing chamber 14 and, as described later, in a state where the toner is retained in the toner receiving region, the upper surface of the retained toner is It may be positioned at least as high as contact. As described above, the upper edges of the pair of projecting walls 82 a forming the projecting region 82 in the end wall 80, the upper edges of the projecting outer walls 82 b, and the central region 53 a of the flange portion 53 in the upper surface wall 50. In between, a toner receiving opening 83 that opens upward outside the first transport path 26a is formed. It should be noted that a developing chamber shutter (not shown) may be provided on the upper wall 50, and the toner receiving opening 54 may be opened and closed by selectively moving the developing chamber shutter between an open position and a closed position. Is preferred.
[0019]
In the illustrated embodiment, the toner container 6 constituting the toner supply means includes a toner container case 60. The toner container case 60 includes a box-shaped toner container main body 61 having an open upper surface, and a lid 62 fixed to the toner container main body 61 by an appropriate means such as ultrasonic welding. The bottom wall of the toner container main body 61 has two arc-shaped portions 61a and 61b whose cross-sectional shapes are arc-shaped. The radius of curvature of the arc-shaped portion 61a is relatively large, and the radius of curvature of the arc-shaped portion 61b is relatively small. The radius of curvature of the arc-shaped portion 61b corresponds to the radius of curvature of the arc-shaped portion formed on the upper end surfaces of the pair of protruding walls 82a constituting the protruding region 82 in the end wall 80 of the housing 8. The arc-shaped portion 61b has a toner discharge opening 62 which may be rectangular. The size of the toner discharge opening 62 is smaller than the toner receiving opening 83. When the toner container 6 is mounted on the housing 8 as required, the lower surface of the arc-shaped portion 61b of the toner container main body 61 is connected to the arc-shaped portion defining the upper end surfaces of the pair of projecting walls 82a via a sealing member (not shown). The toner discharge opening 62 is positioned so as to face above a partial area of the toner receiving opening 83. A part of the lower surface of the arc-shaped portion 61b of the toner container main body 61 is mounted on the inclined inner surface of the protruding outer wall 82b constituting the protruding region 82 via a sealing member (not shown), and the lower surface of the arc-shaped portion 61b. The other partial area is placed on the outer surface of the flange portion 53 of the upper surface wall 50 of the upper surface wall member 12 via a sealing member (not shown). These seal members are provided on the housing 8 side.
[0020]
The toner container main body 61 has a pair of side walls 63 spaced from each other in a direction perpendicular to the plane of FIG. 1 (only one side wall 63 is shown in FIG. 1). A circular opening (not shown) is formed in the other side wall 63, and the toner is filled into the toner container case 60 through the opening. After the toner is filled into the toner container case 60, a closing member (not shown) is fixed to the opening, and the opening is closed. Between both side walls 63 of the toner container main body 61, a toner conveying means 64 extending along the arc-shaped portion 61a and a toner conveying means 65 extending along the arc-shaped portion 61b are provided. The toner conveying means 64 includes a rotation support shaft 64a rotatably mounted between the side walls 63, and a plurality of rectangular conveyance pieces 64b fixed to the rotation support shaft 64a. Each of the transporting pieces 64b can be formed from an appropriate synthetic resin film or sheet. One end of the rotation support shaft 64a protrudes through one side wall 63, and an input gear (not shown) is fixed to the one end.
[0021]
The toner conveying means 65 is constituted by a rotary spiral blade member having a central shaft portion 65a and a spiral blade 65b. One end of the central shaft portion 65a protrudes through one side wall 63, and an input gear (not shown) is fixed to the one end. This input gear is meshed with the input gear of the toner conveying means 64. When the toner container 6 is mounted on the housing 8 as required, the input gear of the toner conveying means 65 is connected to the input gear 32c of the first rotary spiral blade member 30a and the input gear 32d of the second rotary spiral blade member 30b. It is meshed with one of the transmission gears for drivingly connecting the drive source (not shown). Therefore, when the driving source is energized, the first rotating spiral blade member 30a, the second rotating spiral blade member 30b, and the developing sleeve 41 disposed in the developing chamber 14 as described above move the arrow 36 and the developing sleeve 41, respectively. In addition to being rotated in the direction indicated by 39 and the auxiliary rotary spiral blade member 90 being rotated in the direction indicated by the arrow 93, the toner conveying means 64 and 65 of the toner container 6 are also moved in the directions indicated by arrows 66 and 67, respectively. Is rotated. When the toner conveying means 64 is rotated in the direction indicated by the arrow 66, the toner present on the arc portion 61a is conveyed onto the arc portion 61b by the action of the conveying piece 64b, and the toner conveying means 65 is moved in the direction indicated by the arrow 67. , The toner on the arc-shaped portion 61b is conveyed toward the toner discharge opening 62. It should be noted that the illustrated embodiment constructed according to the present invention does not require a dedicated drive source for rotating the toner transport means 64 and 65 of the toner container 6.
[0022]
A container shutter 70 is provided in the toner container case 60. Both ends of the container shutter 70 have a cylindrical shape, and a shutter portion 72 located at an intermediate portion has an arc shape covering an angle range of approximately 200 degrees. The shutter portion 72 has a toner passage opening 74 which may be rectangular. The size of the toner passage opening 74 may be substantially the same as the toner discharge opening 62 formed in the toner container main body 61. A seal member 76, which may be rectangular and extends along the toner passage opening 74, is attached to the outer peripheral surface of the shutter section 72. Conveniently, the size of the seal member 76, which can be formed from a flexible material such as a sponge, is somewhat larger than the toner discharge opening 62 described above. The container shutter 70 is disposed in the arc-shaped portion 61b of the toner container main body 61, and the toner conveying means 65 extends through both ends of the container shutter 70. A turning operation member (not shown) is rotatably disposed on the other side wall 63 of the toner container main body 61, and one end of the turning operation member is connected to one end of the container shutter 70 in the axial direction, and the other end is a toner It projects outward from the other side wall 63 of the container body 61. By turning the turning operation member from the outside of the toner container main body 61, the container shutter 70 is aligned with a closed position (not shown) that closes the toner discharge opening 62 and the toner passage opening 74 is aligned above the toner discharge opening 62. It can be pivoted to any of the positioned open positions (see FIG. 1). When the toner container 6 is not detachably mounted on the housing 8 of the developing device main body 4 (in other words, when the toner supply into the developing chamber 14 is not possible), the container shutter 70 is located at the closed position. . When the container shutter 70 is located at the closed position, the seal member 76 seals and closes the toner discharge opening 62, so that leakage of toner is sufficiently reliably prevented.
[0023]
As shown in FIG. 1, the toner container 6 is detachably mounted on a housing 8 of the developing device main body 4. When the toner container 6 is mounted at a required position of the housing 8 in a state where the developing chamber shutter (not shown) is moved to the open position and the toner receiving opening 83 is opened, the toner discharge opening 62 (in FIG. (Indicated by a dashed line), and a part of the toner receiving opening 83 is aligned in the vertical direction via the container shutter 70. After the toner container 6 is mounted at a required position of the housing 8, the turning operation member is operated to position the container shutter 70 at the open position. As shown in FIG. 1, the toner passage opening 74 of the container shutter 70 is aligned with the toner discharge opening 62 of the toner container main body 61, and the toner discharge opening 62 is opened. The toner discharge opening 62 is located above the toner receiving opening 83 to face the toner receiving opening 83 so as to communicate with the toner receiving opening 83. As a result, the toner container 6 constituting the toner replenishing unit is in a state where the toner can be replenished into the developing chamber 14. Accordingly, the toner in the toner container case 60 is supplied into the developing chamber 14 through the toner passage opening 74, the toner discharge opening 62, and the toner receiving opening 83. The supply of toner will be further described later.
[0024]
In the illustrated developing device having the above-described configuration, the developing chamber 14 is filled with a so-called one-component developer composed of only toner. When the development is performed, the toner is applied to the electrostatic latent image by the toner application unit 40, so that the toner is consumed according to the development. Therefore, it is important to appropriately supply the toner into the developing chamber 14 in accordance with the consumption of the toner. In the illustrated developing device configured according to the present invention, a dedicated driving source for selectively rotating the toner conveying means 64 and 65 provided in the toner container 6 as needed is not required, Supply of toner from the toner container 6 to the developing chamber 14 is appropriately controlled. More specifically, in the illustrated developing device constructed in accordance with the present invention, the above-mentioned driving source (not shown) is urged to perform development by applying toner to the toner applying unit 40 and the stirring and conveying unit 28 (that is, the first rotating spiral). When the blade member 30a, the second rotary spiral blade member 30b), and the auxiliary rotary spiral blade member 90 are rotated, the toner transport means 64 and 65 of the toner container 6 are also connected to the driving source. Are also driven, so that the toner is conveyed toward the toner passage opening 74 and the toner discharge opening 62 in the toner container case 60.
[0025]
On the other hand, in the developing chamber 14, the transport capability of the first rotary spiral blade member 30 a constituting the agitating and transporting means 28 is set in the toner receiving area where the toner is introduced into the developing chamber 14 through the toner receiving opening 83 as described above. In the specific region 47 located on the downstream side of the adjacent region, the specific region 47 is locally reduced. Therefore, the toner is accumulated on the upstream side of the specific area 47, that is, the area adjacent to the toner receiving area. Such stagnation of the toner suppresses the toner from entering the developing chamber 14 through the toner receiving opening 83. The amount of staying toner in an area adjacent to the toner receiving area varies according to the amount of developer in the developing chamber 14 and therefore the amount of toner. Therefore, the degree of suppression of the entry of the toner into the developing chamber 14 is varied depending on the amount of the toner in the developing chamber 14, and when the amount of the toner decreases, the introduction of the toner into the developing chamber 14 increases, and when the amount of the toner increases, The introduction of toner into the developing chamber 14 is reduced. Thus, the supply of toner to the developing chamber 14 is appropriately controlled without directly depending on the drive control of the toner conveying means 64 and 65 of the toner container 6.
[0026]
On the other hand, in the developing device 2 according to the present invention, the housing 8 is provided with a protruding region 82 adjacent to the outside of the first transport path 26a and communicated with the first transport path 26a, and the toner receiving area is It is set in the protruding region 82. That is, the toner receiving area is set to the projecting area 82 located at a position outside the first toner conveying path 26a, and the toner receiving opening 83 is formed in the projecting area 82. The replenishment toner from the toner container 6 is not supplied from just above the first toner transport path 26a, but from a projecting area 82 outside the first toner transport path 26a that defines a part of the transport path. Since the toner is replenished, pulsation and vibration of the toner due to the rotation of the first rotary spiral blade member 30a constituting a part of the stirring and conveying means 28 can be avoided. As a result, in the toner receiving area, there is no possibility that the aggregation or blocking of the toner is generated and the smooth flow of the toner is hindered. Can be replenished as needed. Further, in the developing device 2 according to the present invention, since the auxiliary rotary spiral blade member 90 for discharging the received toner to the first transport path 26a while stirring the toner is disposed in the projecting area 82, the toner receiving area is provided. The toner accumulated in the toner container 6 is discharged to the first toner conveying path 26a while being stirred with the toner supplied from the toner container 6, so that the toner can be more smoothly stirred and conveyed and the toner stirring and charging time can be increased. It becomes longer, which can contribute to better image formation. That is, according to the present invention, it is necessary to provide a toner replenishing unit, in the embodiment, a dedicated driving source for driving the toner conveying units 64 and 65 in the toner container 6 while reliably avoiding excessive pressure of the toner. Therefore, although the manufacturing cost can be sufficiently reduced, the toner can be appropriately supplied from the toner container 6 to the developing chamber 14 in accordance with the decrease in the toner in the developing chamber 14. In the above-described embodiment, the projecting area 82 in which the toner receiving area is set is set at a position downstream of the most upstream position of the first transport path 26a. It may be set, and in this embodiment, substantially the same operation and effect as described above can be obtained.
[0027]
When the toner in the toner container case 60 is exhausted, the toner container 6 needs to be replaced. In this case, the turning operation of the turning operation member is performed from outside the toner container main body 61 to position the container shutter 70 at the closed position for closing the toner discharge opening 62, and then the toner container 6 is moved to the housing of the developing device main body 4. 8 can be disengaged. Next, the developing chamber shutter (not shown) is moved from the open position to the closed position, and thus the toner receiving opening 83 of the developing chamber 14 is closed. After the toner container 6 is detached from the housing 8, a new toner container 6 can be mounted on the housing 8 by the above-described procedure. By turning the turning operation member, the container shutter 70 is positioned at the open position and the toner discharge opening 62 is opened. Thus, the toner can be appropriately supplied from the new toner container 6 into the developing chamber 14.
[0028]
In the developing device 2 according to the present invention, the conveying capacity of the stirring and conveying means 28, in the embodiment, the conveying capacity of the first rotary spiral blade member 30 a is such that the toner is introduced into the developing chamber 14 through the toner receiving opening 83 as described above. Although the specific area 47 is locally reduced in the specific area 47 located on the downstream side of the area adjacent to the toner receiving area, the area is gradually reduced on the downstream side of the area adjacent to the toner receiving area without being locally reduced. It is possible to achieve the object of the present invention in another embodiment in which the amount of the toner is reduced, or in still another embodiment in which the amount of the toner is gradually reduced downstream of an area adjacent to the toner receiving area. As a typical example of another embodiment in which the transport capacity of the first rotary spiral blade member 30a is gradually reduced on the downstream side of the area adjacent to the toner receiving area, for example, the spiral of the first rotary spiral blade member 30a The pitch of the blades 34a may be gradually reduced, or the outer diameter of the spiral blades 34a may be gradually reduced. Further, as a typical example of still another embodiment in which the transport capacity of the first rotary spiral blade member 30a is gradually reduced on the downstream side of the area adjacent to the toner receiving area, for example, the first rotary spiral blade The pitch of the spiral blades 34a of the member 30a can be gradually reduced, or the outer diameter of the spiral blades 34a can be gradually reduced. In any of the embodiments, the conveying ability of the stirring and conveying means 28 is still reduced on the downstream side of the area adjacent to the toner receiving area.
[0029]
In the embodiment of the present invention, when the upper wall member 12 is mounted on the housing body 10, the central region 53 a of the other flange portion 53 is formed by the pair of protruding walls 82 a of the protruding region 82 of the end wall 80. The space extends downward. The upper edge of the pair of projecting walls 82 a forming the projecting region 82 in the end wall 80, the upper edge of the projecting outer wall 82 b, and the central region 53 a of the flange 53 in the upper surface wall 50 are separated from each other. A toner receiving opening 83 that opens upward outside the one transport path 26a is formed. Instead of such an embodiment, the lower end surface of the central region 53a does not extend downward between the pair of protruding walls 82a of the protruding region 82 of the end wall 80. However, it may be configured to extend between the pair of protruding walls 82a at the same level as the lower end surfaces of the other flange portions 53 except for the central region 53a at the other end regions. Further, the projecting bottom wall 82c of the projecting region 82 may be configured to be inclined downward from the lower end of the projecting outer wall 82b toward the arcuate portion 16a of the bottom wall 16. This makes it possible to more effectively prevent toner from remaining.
[0030]
3 and 4 show another embodiment of the developing device according to the present invention. In the developing device shown in FIGS. 3 and 4, the auxiliary stirring and conveying means is constituted by an auxiliary rotary stirring plate member 90A. A plurality of auxiliary rotation stirring plate members 90A, four in the embodiment, are provided, and have a central shaft portion 91A and a stirring plate 95A. The stirring plate 95A extends linearly outward in the radial direction from the outer peripheral surface at 90 ° angular intervals on the outer peripheral surface of the central shaft portion 91A and linearly extends in the axial direction. It is arranged. The configuration of the stirring plate 95A is not limited to the illustrated embodiment. Other configurations of the developing device shown in FIGS. 3 and 4 are substantially the same as those of the developing device shown in FIGS. 1 and 2, and the same portions are denoted by the same reference numerals and description thereof will be omitted. In this embodiment, the toner supplied to the toner receiving area set in the projecting area 82 is discharged to the first transport path 26a while being sufficiently stirred by the auxiliary rotation stirring plate member 90A.
[0031]
FIG. 5 shows still another embodiment of the developing device according to the present invention. In the developing device shown in FIG. 5, the auxiliary stirring / conveying means includes an auxiliary rotating spiral blade and a stirring plate member 90B. The auxiliary rotating spiral blade and stirring plate member 90B has a central shaft portion 91B, a spiral blade 92B, and a stirring plate 95B. A plurality of agitating plates 95B are arranged at 90 ° angular intervals in the circumferential direction of the central shaft portion 91B in the toner conveying direction (rightward in FIG. 5) in the first conveying path 26a. ing. The radial dimension of each of the stirring plates 95B from the central shaft portion 91B is set so as not to exceed the outer diameter of the spiral blade 92B (in the embodiment, the outer diameter of the spiral blade 92B is defined to match the outer diameter of the spiral blade 92B). Has been). The stirring plate 95B has substantially the same radius as the irrigating radius. Other configurations of the developing device shown in FIG. 5 are substantially the same as those of the developing device shown in FIGS. In this embodiment, the toner supplied to the toner receiving area set in the protruding area 82 is discharged to the first transport path 26a while being sufficiently stirred by the auxiliary rotation stirring plate member 90B.
[0032]
FIG. 6 shows still another embodiment of the developing device according to the present invention. In the developing device shown in FIG. 6, only the downstream area in the toner transport direction in the protruding area 82 is communicated with the first transport path 26a, and the upstream area is an end with respect to the first transport path 26a. The communication is completely shut off by the outer vicinity region 81 of the wall 80. The toner receiving opening is set in a region between the protruding outer wall 82b and the opposing outer vicinity region 81 in the protruding region 82 (that is, an upstream region in the protruding region 82). The toner discharge openings 62 are positioned to face each other. An auxiliary rotation stirring member 90 substantially the same as that shown in FIGS. 1 and 2 is provided in the protruding region 82. Since other configurations of the developing device shown in FIG. 6 are substantially the same as those of the developing device shown in FIGS. 1 and 2, the same portions are denoted by the same reference numerals and description thereof will be omitted. In this embodiment, the toner supplied to the toner receiving area set in the protruding area 82 is discharged to the first transport path 26a while being stirred by the auxiliary rotation stirring member 90.
[0033]
FIG. 7 shows still another embodiment of the developing device according to the present invention. In the developing device shown in FIG. 7, the projecting area 82 extends further upstream from the upstream end of the housing 8 in the toner conveying direction in the first conveying path 26a. The extension from the upstream end includes an extension wall 84, a projecting outer wall 82b, and a projecting wall 82a. The extension wall 84 extends on the extension of the outer vicinity region 81 of the end wall 80. In the developing device shown in FIG. 7, as in the developing device shown in FIG. 6, only the downstream area in the toner transport direction of the protruding area 82 is communicated with the first transport path 26a. The upstream area is completely shut off from the first transport path 26a by an area 81 outside the end wall 80. The toner receiving opening is set in the most upstream region of the protruding region 82, that is, the most upstream region of the extension portion. In the illustrated embodiment, the toner container 6 is adjacent to the side wall 20 of the developing device main body 4 and orthogonal to the extending direction of the first and second rotating spiral members 30a and 30b (the left-right direction in FIG. 7). It is arranged. The toner discharge opening 62 of the toner container 6 is positioned above and opposed to the toner receiving opening. Other configurations of the developing device shown in FIG. 7 are substantially the same as those of the developing device shown in FIGS. In this embodiment, the toner supplied to the toner receiving area set in the protruding area 82 is discharged to the first transport path 26a while being stirred by the auxiliary rotation stirring member 90. In this embodiment, the toner container 6 can be disposed at a position laterally separated from the developing device main body 4, which is advantageous in layout.
[0034]
In the above embodiment according to the present invention, in order to show the features of the present invention as simply and clearly as possible, the lock means for releasably locking the toner container 6 and the upper wall member 12 including the developing chamber shutter, and The configuration of the toner container 6 and the like including the container shutter 70 is shown in a minimally simplified form. However, as for the configuration of each of the above members except for the configuration that constitutes the feature of the present invention described above, basically, the configuration disclosed in Patent Document 1 introduced above may be used. Is described in Patent Document 1 and is left to that, and is omitted in the present specification and drawings. As a matter of course, the configuration disclosed in Patent Document 1 may or may not be used for configurations other than the above-described configuration which is a feature of the present invention.
[0035]
Further, in the above-described embodiment, the toner replenishing unit for replenishing the toner into the developing chamber 14 includes the toner container 6 detachably mounted on the housing 8, but is not limited to this. The toner container 6 may be detachably attached to the housing 8 and / or the image forming apparatus main body. Furthermore, another toner replenishing means, for example, a toner hopper which is mounted on the housing 8 and / or the main body of the image forming apparatus and replenishes the toner when the stored toner is exhausted (the toner hopper is provided in the developing chamber 14). Transport means for transporting and replenishing). In any state of the toner replenishing means, the toner receptive opening 54 or substantially the same as the toner receptive opening 54 or the corresponding toner receptive opening when the toner replenishment into the developing chamber 14 is possible. It is essential that a toner discharge opening 62 or a toner discharge opening corresponding thereto be formed opposite to the toner reception opening 54 corresponding to the toner receiving opening 54 or the corresponding toner receiving opening.
[0036]
When the toner replenishing means is composed of at least a toner container 6 or a toner hopper mounted on the image forming apparatus main body, the toner replenishing unit is positioned at a required position where toner replenishment into the developing chamber 14 can be performed. The toner discharge opening 62 or the corresponding toner discharge opening is aligned above the toner receiving opening 54 or the corresponding toner receiving opening so as to communicate with the toner receiving opening 54 or the corresponding toner receiving opening ( It is common to be positioned (facing). However, even in the upper position, the position may be shifted in the horizontal direction on the layout. In this case, a proper communication path between the toner discharge opening 62 or the corresponding toner discharge opening and the toner receiving opening 54 or the corresponding toner receiving opening, that is, an appropriate communication path allowing the toner to freely fall. It goes without saying that a communication path is provided. Therefore, in the present invention, the "toner replenishing means includes a toner discharging portion positioned above the toner receiving opening substantially opposed to the toner receiving opening so as to communicate with the toner receiving opening when the toner can be supplied into the developing chamber. The phrase “opening is formed” means that any embodiment is included. Further, as is easily understood from the above description, in the developing device of the present invention, “provided with a toner replenishing unit for replenishing toner in the developing chamber” means that the toner replenishing unit is directly mounted on the developing device main body 4. The toner supply means is mounted or disposed on the image forming apparatus main body, or the toner supply means is mounted across the image forming apparatus main body and the developing device main body 4. Is also included. It goes without saying that an embodiment in which the developing device main body 4 or the developing device 2 is detachably mounted as a unit on the image forming machine main body is also included in the present invention.
[0037]
【The invention's effect】
According to the developing device of the present invention, a dedicated drive source for driving the toner conveying unit in the toner replenishing unit including the toner container or the toner hopper while reliably avoiding excessive pressure of the toner in the toner receiving area is required. Accordingly, although the manufacturing cost can be sufficiently reduced, the toner can be appropriately replenished from the toner replenishing means to the developing chamber in accordance with the decrease in the toner in the developing chamber. That is, according to the developing device of the present invention, the replenishment toner from the toner replenishing means such as the toner container or the toner hopper is not replenished from directly above the transport path such as the first transport path, but instead is supplied outside the transport path. Since the toner is replenished from the protruding area, the pulsation and vibration of the toner due to the rotation of the stirring and conveying means can be avoided, and the aggregation and blocking of the toner can be prevented and the flow of the toner can be smoothed.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view illustrating a preferred embodiment of a developing device configured according to the present invention.
FIG. 2 is a horizontal sectional view of a developing device main body in the developing device shown in FIG.
FIG. 3 is a cross-sectional view illustrating another embodiment of a developing device configured according to the present invention.
FIG. 4 is a horizontal sectional view of a developing device main body in the developing device shown in FIG. 3;
FIG. 5 is a horizontal sectional view of a developing device main body in still another embodiment of the developing device configured according to the present invention.
FIG. 6 is a horizontal sectional view of a developing device main body in still another embodiment of the developing device configured according to the present invention.
FIG. 7 is a horizontal sectional view of a developing device main body in still another embodiment of the developing device configured according to the present invention.
[Explanation of symbols]
2 Developing device
4 Developing device body
6 Toner container
8 Housing
14 Developing room
24 partition
26a First transport path
26b Second transport path
27a, 27b communication passage
28 Stirring and conveying means
30a First rotating spiral blade member (first stirring and conveying means)
32a center shaft
34a spiral blade
30b Second rotating spiral blade member (second stirring and conveying means)
32b center shaft
34b spiral blade
40 Toner application means
61 Toner container body
62 Toner discharge opening
80 End Wall
81 Outside area
82 Projection area
82a Projecting wall
82b protruding outer wall
82c protruding bottom wall
83 Toner receiving opening
84 Extension Wall
90 auxiliary rotating spiral blade member (auxiliary stirring and conveying means)
90A auxiliary rotating stir plate member
90B Auxiliary rotating spiral blade & stirring plate member

Claims (8)

A housing having a developing chamber for defining a toner conveying path; a stirring and conveying means arranged in the developing chamber for conveying the toner through the conveying path while stirring; and an electrostatic latent image for developing the toner in the developing chamber. A toner application unit for applying an image to the image; and a toner supply unit for supplying toner to the developing chamber. The housing has a toner receiving opening located above the toner receiving area. In the developing device, in a state where toner can be supplied to the developing chamber, a toner discharge opening is formed substantially above the toner receiving opening opposite to the toner receiving opening so as to communicate with the toner receiving opening.
In the housing, a protruding area adjacent to the outside of the conveying path and communicated with the conveying path is provided, the toner receiving area is set in the protruding area, and the conveying capacity of the stirring conveying means is in the toner conveying path, Auxiliary agitating and conveying means for discharging the toner to the conveying path while agitating the received toner is provided in the protruding area, which is reduced on the downstream side of the area adjacent to the toner receiving area.
A developing device, comprising: A housing having a developing chamber for defining a toner circulation path, a stirring and conveying means provided in the development chamber for conveying the toner through the circulation path while stirring, and an electrostatic latent image for developing the toner in the development chamber. A toner supply unit for applying toner to the image; and a toner supply unit for supplying toner to the developing chamber. The circulation path includes a first conveyance path extending in parallel with the toner application unit, and a first conveyance path. A second conveying path extending between and along the conveying path and the toner applying unit; and a communication path communicating between both end regions of the first and second conveying paths. A toner receiving opening located above the receiving area is formed, and the toner replenishing means has a toner receiving opening substantially in communication with the toner receiving opening when the toner can be replenished into the developing chamber. In the developing device having the toner discharge opening positioned above the receiving opening is formed,
The housing is provided with a projecting area adjacent to the outside of the first conveying path and communicated with the first conveying path, the toner receiving area is set in the projecting area, and the conveying capacity of the stirring conveying means is: In the first conveyance path, the amount is reduced on the downstream side of the area adjacent to the toner receiving area, and in the protruding area, an auxiliary stirring conveyance means for discharging the received toner to the conveyance path while stirring is provided. ing,
A developing device, comprising: The housing includes an end wall that defines the outside of the first conveyance path, and the end wall extends along the stirring and conveyance means at a position near the outside of the stirring and conveyance means disposed in the first conveyance path. And a pair of protruding regions protruding outward from the outer proximate region. The protruding region includes a pair of protruding walls that oppose each other at a distance in the toner conveying direction in the first conveying path; 3. The developing device according to claim 2, further comprising a protruding outer wall and a protruding bottom wall extending between the protruding walls, and wherein the auxiliary stirring and conveying means is rotatably supported between the pair of protruding walls. 4. The developing device according to claim 2, wherein an entire area of the protruding area in the toner transport direction communicates with the first transport path. 5. 4. The developing device according to claim 2, wherein only the downstream area in the toner transport direction in the protruding area communicates with the first transport path. 5. The developing device according to claim 5, wherein the protruding region extends further upstream from an upstream end of the housing in the toner transport direction in the first transport path. The auxiliary stirring and conveying means is an auxiliary rotating spiral blade member including a central shaft portion and a spiral blade, or an auxiliary rotating stirring plate member including a central shaft portion and a stirring plate, or an auxiliary rotation including a central shaft portion, a spiral blade, and a stirring plate. The developing device according to claim 2, wherein the developing device comprises a spiral blade and a stirring plate member. The developing device according to claim 1, wherein the toner replenishing unit is a toner container detachably mounted on the housing.

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