JP2004117614A - Developing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To avoid pressurization of a toner and appropriately replenish the toner from a toner container 6 to a developing chamber 14 in accordance with a decreases in toner in the developing chamber 14 . <P>SOLUTION: A developing device 2 is provided with a housing 8 having the developing chamber 14, an agitation-conveyance means 28 disposed in the developing chamber 14, and the toner container 6. The developing chamber 14 has a first conveyance path 26a, a second conveyance path 26b, and communicating paths 27a and 27b. In the developing chamber 14, a toner receiving opening 83 situated above a toner receiving area is made. A toner discharging opening 62 is made in the toner container 6. The conveying capability of the agitation-conveyance means 28 is reduced on the downstream side of the toner receiving area. The housing 8 has a projecting area 82 disposed adjacent to the outside of the first conveyance path 26a and communicating with the first conveyance path 26a. The toner receiving area is disposed 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 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 toner in a developing chamber to an electrostatic latent image to be developed, and a toner container detachably mounted on a housing, which is a toner replenishing unit for replenishing toner into the developing chamber. ing. 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 A toner application unit for applying the toner to the electrostatic latent image to be developed, and a toner replenishing unit for replenishing the toner into the developing chamber. The developing chamber includes a toner positioned above the toner receiving area. A receiving opening is formed, and the toner replenishing means includes a toner positioned 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. In the developing device in which the discharge opening is formed,
The conveying capacity of the stirring and conveying means is reduced on the downstream side of the toner receiving area. The housing is provided with a protruding area adjacent to the outside of the conveying path and communicated with the conveying path, and the toner receiving area is protruded. Set in the 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. The developing chamber has a toner receiving opening located above the toner receiving area, and the toner replenishing means communicates with the toner receiving opening when toner can be supplied to the developing chamber. Seemingly tona In the developing device having the toner discharge opening positioned above the toner receiving opening opposite the receiving opening is formed,
The conveying capacity of the stirring and conveying means is reduced on the downstream side of the toner receiving area, and the housing is provided with a protruding 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 protruding area,
A developing device is provided.
Preferably, the toner supply means is a toner container detachably mounted on the housing.
The housing includes an end wall that defines the outside of the first conveyance path, and the end wall includes an outer vicinity area extending along the first conveyance path at a position near the outside of the first conveyance path, A projection area projecting outward from the area, the projection area extending between the pair of projection walls and the pair of projection walls facing each other at an interval in the toner transport direction in the first transport path. And a projecting outer wall.
According to the developing device of the present invention configured as described above, the replenishment toner from the toner replenishment means including the toner container or the toner hopper may be replenished from directly above the transport path such as the first transport path. Instead, the toner is replenished from the projecting area outside the transport path, so that the pulsation and vibration of the toner due to the rotation of the stirring and transporting means can be avoided, and the aggregation and blocking of the toner can be prevented and the flow of the toner can be smoothed.
[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 above-described circulation path, which constitutes a conveyance path through which the toner is conveyed, there is provided a stirring and conveying unit 28 for conveying the toner through the circulation path while stirring the toner. 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 rotary 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 developing chamber 14 has a toner receiving opening 83 formed above the toner receiving area. The housing 8 has a protruding area 82 adjacent to the outside of the first transport path 26a (outside on the side opposite to the side facing the second transport path 26b) and communicated with the first transport path 26a. It is important that the toner receiving area is set within the protruding area 82. More specifically, the housing 8 includes an end wall 80 that defines the outside of the first transport path 26a. The end wall 80 includes an outer vicinity area 81 extending along the first conveyance path 26a at a position near the outside of the first conveyance path 26a, and a protruding area 82 projecting outward from the outer vicinity area 81. . The protruding region 82 includes a pair of protruding walls 82a facing each other at an interval in the toner conveying direction in the first conveying path 26a, and a protruding outer wall 82b extending between the pair of protruding walls 82a. The protruding outer wall 82b is inclined outward from the bottom of the housing 8 upward. In other words, the protruding outer wall 82b is inclined upward and outward from the arc-shaped portion 16a of the bottom wall 16 of the housing 8. This configuration smoothly discharges the toner received in the protruding area 82 to the first conveyance path 26a as described later, and contributes to preventing the toner from remaining. 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 outer wall 82b. I have. The toner is introduced into the toner receiving area through the toner receiving opening 83. In addition, the toner receiving opening 83 may be formed so as to cover a part of an upper surface wall 50 to be described later so as to cover an upper end portion of the protruding region 82, or to cover the protruding region 82 detachably. It may be formed on a cover member (not shown) arranged as described above.
[0015]
In the present invention, the toner conveying capacity of the stirring and conveying means 28 is reduced on the downstream side of 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 the toner receiving area where the toner is introduced into the developing chamber 14 through the toner receiving opening 83.
[0016]
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.
[0017]
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 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.
[0018]
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.
[0019]
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.
[0020]
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, the toner conveying means 64 and 65 of the toner container 6 are also rotated in the directions indicated by arrows 66 and 67, respectively. 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.
[0021]
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. 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 attached to 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.
[0022]
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.
[0023]
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 energized in order to perform development, and the stirring and conveying means 28 (that is, the first rotary spiral) together with the toner applying means 40 are applied. When the blade member 30a and the second rotary spiral blade member 30b) are rotated, the toner conveying means 64 and 65 of the toner container 6 are also connected to the driving source. As a result, the toner is conveyed toward the toner passage opening 74 and the toner discharge opening 62 in the toner container case 60.
[0024]
On the other hand, in the developing chamber 14, the transport capability of the first rotary spiral blade member 30a constituting the agitating and transporting means 28 corresponds to the toner receiving area where the toner is introduced into the developing chamber 14 through the toner receiving opening 83 as described above. It is reduced locally in the specific area 47 located on the downstream side. Therefore, the toner stays upstream of the specific area 47, that is, in 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 the toner receiving area varies according to the amount of the developer in the developing chamber 14 and thus the amount of the 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.
[0025]
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. That is, according to the present invention, the toner replenishing means, in the embodiment, a dedicated driving source for driving the toner conveying means 64 and 65 in the toner container 6 is required 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 conveyance path 26a. It may be set, and in this embodiment, substantially the same operation and effect as described above can be obtained.
[0026]
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.
[0027]
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. Another embodiment in which the specific area 47 located locally on the downstream side of the toner receiving area to be reduced is locally reduced, but is not reduced locally but is gradually reduced downstream of the toner receiving area. Alternatively, it is possible to achieve the object of the present invention by using still another embodiment in which the amount is reduced stepwise on the downstream side of 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 toner receiving area, for example, the pitch of the spiral blades 34a of the first rotary spiral blade member 30a , Or the outer diameter of the spiral blade 34a is 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 toner receiving area, for example, the spiral of the first rotary spiral blade member 30a is used. The pitch of the blades 34a may be gradually reduced, or the outer diameter of the spiral blades 34a may be gradually reduced. In any of the embodiments, the conveying ability of the stirring and conveying means 28 is still reduced downstream of the toner receiving area.
[0028]
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.
[0029]
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. 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. 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.
[0030]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to the developing device by this invention, while avoiding excessive compression of a toner reliably, it does not require the exclusive drive source for driving the toner conveyance means in a toner container, and therefore reduces production cost sufficiently. However, the toner can be appropriately supplied from the toner container 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. Is supplied from the protruding area of the toner, 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.
[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
83 Toner receiving opening

Claims (4)

A housing having a developing chamber for defining a toner conveying path; a stirring and conveying means disposed 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 developing chamber has a toner receiving opening located above the toner receiving area. The replenishing means has a toner discharge opening formed substantially above the toner receiving opening opposite to the toner receiving opening so as to communicate with the toner receiving opening when the toner can be supplied to the developing chamber. At
The conveying capacity of the agitating and conveying means is reduced on the downstream side of the toner receiving area, and the housing is provided with a projecting area adjacent to the outside of the conveying path and communicated with the conveying path, and the toner receiving area has Set in the 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 the conveying path and the toner application unit along the conveying path; and a communication path communicating between both end areas of the first and second conveying paths. A toner receiving opening located above the toner receiving area, and the toner replenishing means is substantially opposed to the toner receiving opening so as to communicate with the toner receiving opening when toner can be supplied to the developing chamber. The toner In the developing device having the toner discharge opening positioned above the inlet opening is formed,
The conveying capacity of the stirring and conveying means is reduced on the downstream side of the toner receiving area, and the housing is provided with a protruding 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 protruding area,
A developing device, comprising: 3. The developing device according to claim 1, wherein the toner replenishing means is a toner container detachably mounted on the housing. The housing includes an end wall that defines an outside of the first conveyance path, and the end wall includes an outer vicinity area extending along the first conveyance path at a position near the outside of the first conveyance path, and an outer vicinity area that extends along the first conveyance path. A projection area protruding outward from the area, the projection area extending between the pair of projection walls and the pair of projection walls opposed to each other in the first transport path at an interval in the toner transport direction. The developing device according to claim 2, further comprising a protruding outer wall.

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