JP2004151276A - Developing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To ensure stable amount of conveyance even in a case where the fluidity of toner changes and to hinder flocculation of the toner in a development chamber 14 . <P>SOLUTION: The developing device 2 includes a stir-conveyance means 28 disposed in the development chamber 4 and a toner container 6. The developing chamber 14 has first and second conveyance paths 26a and 26b and communication paths 27a and 27b. The stir-conveyance means 28 includes a first rotary helical blade member 30a for the first conveyance path 26a. In the development chamber 14, a toner receiving opening 54 is formed above a toner receiving area provided on the first conveyance path 26a. A toner discharging opening is formed in the toner container 6. In a specific area X which is downstream of the toner receiving area, the center shaft 32a of the first rotary helical blade member 30a has a large diameter part Rx that is larger than the diameter of the other parts, thereby locally reducing the conveying capability. <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 and published (see Patent Document 1). The developing device 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, and developing the toner in the development chamber. A toner application unit for applying an electrostatic latent image to be provided, and a toner container detachably mounted on a housing for replenishing toner into 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 directly depend on the drive control of the toner conveying means of the toner container, but depends on the amount of toner staying in the toner receiving area, in other words, according to the amount of toner in the developing chamber. Automatically 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. Therefore, it is not necessary to control the sensor and a dedicated driving source such as an electric motor provided only for driving the toner conveying means of the toner container is not required. An excellent effect is obtained that the toner can be appropriately replenished from the toner container to the developing chamber in accordance with the decrease of the toner in the room. When a developing device capable of obtaining such excellent effects is put to practical use, a stable conveyance amount can be ensured even with a change in the fluidity of the toner. In the above, the structure of the means for generating toner stagnation is simple, can be easily put into practical use at low cost, and stable conveyance is ensured even when the amount of toner is small (in other words, even when the volume of toner is low). The installation time can be shortened, and stable development action can be ensured until the toner is exhausted. The mold can be easily modified, and fine adjustment can be made to obtain the required performance at an early stage. It is required to shorten the development time and reduce the development cost.
[0006]
SUMMARY OF THE INVENTION It is an object of the present invention to secure a stable transport amount even with a change in toner fluidity, thereby enabling toner in a developing chamber to be less likely to be aggregated, and a toner replenishing means including a toner container or a toner hopper. A dedicated driving source such as an electric motor provided only for driving the toner conveying means in the above-mentioned method is not required, so that the cost can be reduced accordingly, and further, the toner can be reduced in accordance with the decrease of the toner in the developing chamber. An object of the present invention is to provide a new and improved developing device capable of appropriately replenishing toner from a replenishing means to a developing chamber.
[0007]
Another object of the present invention is to provide a simple configuration of a means for generating toner stagnation in a toner receiving area, which can be easily put into practical use at low cost, and to drive a toner conveying means in a toner replenishing means such as a toner container or a toner hopper. This eliminates the need for a dedicated drive source such as an electric motor provided only for the purpose of reducing the cost, thereby reducing costs.Furthermore, as the amount of toner in the developing chamber decreases, the toner is supplied from the toner replenishing means to the developing chamber. An object of the present invention is to provide a new and improved developing device capable of appropriately replenishing toner.
[0008]
Still another object of the present invention is to ensure stable conveyance even when the amount of toner is small (in other words, even when the volume of the toner is low), thereby shortening the installation time and reducing the amount of toner. A stable developing action can be ensured, and further, a dedicated drive source such as an electric motor provided only for driving the toner conveying means in the toner replenishing means including a toner container or a toner hopper becomes unnecessary, Accordingly, it is an object of the present invention to provide a new and improved developing device capable of reducing the cost and appropriately replenishing the toner from the toner replenishing means to the developing chamber according to the decrease of the toner in the developing chamber.
[0009]
Still another object of the present invention is to enable easy adjustment of the mold and fine adjustment for obtaining the required performance stably at an early stage. Therefore, it is possible to shorten the development period and the development cost, and also to reduce the toner container or the toner cost. A dedicated driving source, such as an electric motor, provided only for driving the toner conveying means in the toner replenishing means such as a toner hopper becomes unnecessary, so that the cost can be reduced accordingly, and further, the toner in the developing chamber is reduced. It is an object of the present invention to provide a new and improved developing device capable of appropriately replenishing toner from a toner replenishing means to a developing chamber in accordance with the following.
[0010]
[Means for Solving the Problems]
According to 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 the toner, A toner application unit for applying an electrostatic latent image to be developed and a toner replenishing unit for replenishing toner in the developing chamber are provided. The developing chamber has a toner receiving opening located above the toner receiving area. The toner replenishing means has a toner discharge opening positioned substantially above the toner receiving opening so as to communicate with the toner receiving opening when the toner can be supplied to the developing chamber. In the developing device being formed,
The conveying capacity of the stirring and conveying means is locally reduced in a specific area on the downstream side of the toner receiving area of the conveying path, and the stirring and conveying means is constituted by a rotating spiral blade member including a central shaft portion and a spiral blade. In the specific region, a large-diameter portion having a larger diameter than other regions is formed in the central shaft portion of the rotating blade member.
A developing device is provided.
Preferably, the toner supply means is a toner container detachably mounted on the housing.
The toner conveyance path includes a circulation path, and the circulation path extends along the first conveyance path extending parallel to the toner application unit and between the first conveyance path and the toner application unit. A second conveying path, and a communication path that communicates between both end regions of the first and second conveying paths, wherein the stirring and conveying means includes a first stirring and conveying means disposed on the first conveying path. And a second stirring and conveying means disposed on the second conveying path, wherein the first stirring and conveying means is constituted by a first rotating spiral blade member including a central shaft portion and a spiral blade. Preferably, the rotary spiral blade member is formed of a first rotary spiral blade member, and the large diameter portion is formed on a central shaft portion of the first rotary spiral blade member.
According to the present invention, there is also provided 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 a toner in the developing chamber. And a toner applying means for applying to the electrostatic latent image to be developed,
The stirring and conveying means is constituted by a rotating spiral blade member including a central shaft portion and a spiral blade, and a large diameter portion is formed in a part of the central shaft portion of the rotating spiral blade member.
A developing device is provided.
[0011]
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.
[0012]
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.
[0013]
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.
[0014]
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. .
[0015]
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 drive 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 (in the same direction indicated by an arrow 36 in FIGS. 1 and 2). (rpm).
[0016]
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. A toner receiving area is set in the first transport path 26a. The toner is introduced into the toner receiving area through a toner receiving opening 54 (shown by a two-dot chain line in FIG. 2) described in detail later. In the embodiment, the toner receiving area is set in an area upstream of the center of the first transport path 26a (an area on the left side of the center in FIG. 2).
[0017]
In the present invention, the transport capacity of the stirring transport unit 28 is locally reduced in the specific area X downstream of the toner receiving area in the circulation path. More specifically, in the specific region X, a large-diameter portion Rx having a larger diameter than the other regions is formed in the central shaft portion 32a of the first spiral blade member 30a. In the embodiment, the diameter of the large diameter portion Rx is substantially constant. Then, the diameter of the central shaft portion 32a of the first rotary spiral blade member 30a in the other region, the diameter of the central shaft portion 32b of the second rotary spiral blade member 30b, and the diameter of the spiral blade 34a of the first rotary spiral blade member 30a. The diameter, the diameter of the spiral blade 34b of the second rotary spiral blade member 30b, the pitch of the spiral blade 34a of the first rotary spiral blade member 30a, and the pitch of the spiral blade 34b of the second rotary spiral blade member 30b are respectively: They are substantially the same. Therefore, the toner conveying capacity (per unit pitch) of the stirring and conveying means 28 is locally reduced in the specific area X. The large diameter portion Rx can be formed to change continuously or stepwise in the axial direction of the central shaft portion 32b.
[0018]
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. The developing chamber 14 contains a one-component developer made of only magnetic toner, 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 blade. By the action of the spiral blade member 30b, it 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.
[0019]
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. An elongated immersion area 52 extending in the width direction (the direction perpendicular to the paper surface in FIG. 1) is formed on the upper surface wall 50. The cross-sectional shape of the immersion area 52 is arc-shaped. In the immersion area 52, a toner receiving opening 54, which may be rectangular, is formed. The toner receiving opening 54 is positioned above and opposed to a toner receiving area set in the first transport path 26a. A developing chamber shutter (not shown) is provided on the upper wall 50, and the toner receiving opening 54 can be opened and closed by selectively moving the developing chamber shutter between an open position and a closed position.
[0020]
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 immersion area 52 defined on the upper surface wall 50 of the upper surface wall member 12 described above. The arc-shaped portion 61b has a toner discharge opening 62 which may be rectangular. When the toner container 6 is mounted on the housing 8 as required, the arc-shaped portion 61b of the toner container main body 61 is positioned opposite to the immersion area 52 defined on the upper surface wall 50 of the upper surface wall member 12, and A toner discharge opening 62 is located above the receiving opening 54. To avoid so-called blocking of the toner near the toner discharge opening 62 and / or the toner receiving opening 54, the width and the length of the toner discharge opening 62 are substantially equal to the width and the length of the toner receiving opening 54. Preferably it is the same or somewhat smaller.
[0021]
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.
[0022]
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 in accordance with the present invention does not require a dedicated drive source such as an electric motor provided solely for rotating the toner transport means 64 and 65 of the toner container 6. It is.
[0023]
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 attached to the housing 8 of the developing device main body 4, 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.
[0024]
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 developer container shutter (not shown) is moved to the open position to open the toner receiving opening 54 and the toner container 6 is mounted at a required position of the housing 8, the toner discharging opening 62 of the toner container main body 61 and the upper wall member 12 are opened. Are aligned in the up-down 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 54 so as to face the toner receiving opening 54 so as to communicate with the toner receiving opening 54. 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. Therefore, 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 54.
[0025]
In the illustrated developing device of the above-described embodiment, the developing chamber 14 is filled with a so-called one-component developer composed of only magnetic 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 to perform development, and the toner agitating / conveying means 28 (i.e., the first rotating When the spiral blade member 30a and the second rotating spiral blade member 30b) are rotated, the toner conveying means 64 and 65 of the toner container 6 are also connected to the above-mentioned driving source, and thus the toner conveying means 64 and 65 of the toner container 6 are also connected. Is also driven, so that the toner is transported in the toner container case 60 toward the toner passage opening 74 and the toner discharge opening 62.
[0026]
On the other hand, in the developing chamber 14, the conveying capability of the first rotary spiral blade member 30 a constituting the stirring and conveying means 28 is limited to the toner receiving area where the toner is introduced into the developing chamber 14 through the toner receiving opening 54 as described above. It is locally reduced in the specific region X on the downstream side. Therefore, the toner stays on the upstream side of the specific area X, 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 54. The amount of staying toner in the toner receiving area varies according to the amount of toner in the developing chamber 14. 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.
[0027]
According to the developing device of the present invention, in the specific region X, the large-diameter portion Rx having a larger diameter than the other regions is formed in the central shaft portion 32a of the first rotating spiral blade member 30a. As described above, the transport capability of the first rotary spiral blade member 30a is locally reduced in the specific region Rx on the downstream side of the toner receiving region where the toner is introduced into the developing chamber 14 through the toner receiving opening 54. Such a configuration makes it possible to locally reduce the outer diameter of the spiral blade 34a of the first rotary spiral blade member 30a, or to locally reduce the pitch. It is possible to secure a stable conveyance amount with respect to the change, and thus it is possible to prevent the toner in the developing chamber from being easily aggregated. The reason for this is that the outer diameter of the spiral blade 34a of the first rotary spiral blade member 30a is locally reduced, or the pitch is locally reduced. Is increased, it is assumed that the compressive force of the toner by the spiral blade 34a in the specific region Rx is dispersed outward, and the local compression of the toner is reduced.
[0028]
According to the developing device of the present invention, the means for generating the stagnation of the toner in the toner receiving area is, as described above, provided in the specific area X at the center shaft portion 32a of the first rotary spiral blade member 30a. Since it is constituted by forming the large-diameter portion Rx having a larger diameter than that in the region, it can be put to practical use at a very simple and low cost.
[0029]
According to the developing device of the present invention, stable conveyance is possible even when the amount of toner is small (in other words, even when the volume of toner is low). This is because, as described above, the local pressure of the toner in the specific region Rx is reduced. As a result, it is possible to shorten the installation time until the use of the developing device can be started, and it is possible to secure a stable developing action from when the use of the developing device is started until the toner runs out.
[0030]
According to the developing device of the present invention, the mold can be easily corrected, and fine adjustment can be performed to obtain the required performance quickly and stably. Therefore, the development period can be shortened and the development cost can be reduced. That is, in the prototype stage before the present invention is put to practical use, in order to secure the required stable performance, compared with changing the outer diameter or the pitch of the spiral blade 34a of the first rotary spiral blade member 30a. By changing the diameter of the central shaft portion 32a of the first rotary spiral blade member 30a, it is easy to correct and fine-adjust the mold due to its structure, and the production error in prototypes and mold products is also reduced. Since the number is small, the above-described effects can be obtained.
[0031]
According to the developing device of the present invention, in addition to the above-described effects, further, a toner replenishing unit, and in the embodiment, an electric motor provided only for driving the toner conveying units 64 and 65 in the toner container 6, etc. And the cost can be reduced accordingly, and further, 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. It is.
In the above embodiment, the toner receiving area is set at a position downstream of the most upstream position of the first transport path 26a. However, the toner receiving area may be set at the most upstream position or a position in the vicinity thereof. In the embodiment, substantially the same operation and effect as described above can be obtained.
[0032]
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 54 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.
[0033]
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.
[0034]
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.
[0035]
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.
[0036]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to the developing device by this invention, the stable conveyance amount can be ensured also with respect to the change of the fluidity of a toner, and therefore, it is possible to prevent the toner in a developing chamber from being aggregated easily, and it comprises a toner container or a toner hopper. A dedicated driving source such as an electric motor provided only for driving the toner conveying means in the toner replenishing means is not required, so that the cost can be reduced correspondingly, and further, the toner in the developing chamber can be reduced. Accordingly, the toner can be appropriately supplied from the toner supply unit to the developing chamber.
In addition, the configuration of the means for generating toner stagnation in the toner receiving area is simple, can be easily put into practical use at low cost, and is provided for the purpose of only driving the toner transport means in the toner replenishing means including a toner container or a toner hopper. This eliminates the need for a dedicated drive source such as an electric motor, thereby reducing costs. Further, as the amount of toner in the developing chamber decreases, toner is supplied from the toner replenishing means to the developing chamber as appropriate. be able to.
Furthermore, even when the amount of toner is small (in other words, when the volume of the toner is low), stable conveyance can be ensured, so that the installation time can be shortened, and a stable developing action can be performed until the toner runs out. In addition, a dedicated driving source such as an electric motor provided only for driving the toner conveying unit in the toner replenishing unit including the toner container or the toner hopper becomes unnecessary, and the cost is reduced accordingly. In addition to reducing the amount of toner in the developing chamber, the toner can be appropriately supplied from the toner replenishing means to the developing chamber.
In addition, the mold can be easily corrected and fine adjustment can be performed to obtain the required performance at an early stage. Therefore, the development period and the development cost can be reduced, and the toner including a toner container or a toner hopper can be used. A dedicated drive source, such as an electric motor, provided only for driving the toner conveying means in the replenishing means becomes unnecessary, so that the cost can be reduced accordingly, and further, the toner is replenished in accordance with the decrease in the toner in the developing chamber. The toner can be appropriately replenished from the means to the developing chamber.
[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 sectional view of a developing device main body in the developing device shown in FIG.
[Explanation of symbols]
2 Developing device 4 Developing device main body 6 Toner container 8 Housing 14 Developing chamber 24 Partition 26a First transport path 26b Second transport path 27a, 27b Communication path 28 Stirring transporting means 30a First rotating spiral blade member (first Stirring and conveying means)
32a central shaft portion 34a spiral blade 30b second rotary spiral blade member (second stirring and conveying means)
32b Central shaft portion 34b Spiral blade 40 Toner applying means 54 Toner receiving opening 61 Toner container main body 62 Toner discharging opening Rx Large diameter portion X Specific area

Claims (4)

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 developing chamber has a toner receiving opening located above the toner receiving area. The replenishing means is provided with 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 toner can be supplied to the developing chamber. At
The conveying capacity of the stirring and conveying means is locally reduced in a specific area on the downstream side of the toner receiving area of the conveying path, and the stirring and conveying means is constituted by a rotating spiral blade member including a central shaft portion and a spiral blade. In the specific region, a large-diameter portion having a larger diameter than other regions is formed in the central shaft portion of the rotating blade member.
A developing device, comprising: The developing device according to claim 1, wherein the toner replenishing means is a toner container detachably mounted on the housing. The toner conveyance path includes a circulation path, and the circulation path extends along the first conveyance path extending parallel to the toner application unit and between the first conveyance path and the toner application unit. A second conveying path; and a communication path that communicates between both end regions of the first and second conveying paths. And a second stirring and conveying means disposed on the second conveying path, wherein the first stirring and conveying means is constituted by a first rotating spiral blade member including a central shaft portion and a spiral blade. 3. The developing device according to claim 1, wherein said rotary spiral blade member is formed of a first rotary spiral blade member, and said large diameter portion is formed on a central shaft portion of said first rotary spiral blade member. apparatus. 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 developing device provided with a toner application unit for applying to the image,
The stirring and conveying means is constituted by a rotating spiral blade member including a central shaft portion and a spiral blade, and a large diameter portion is formed in a part of the central shaft portion of the rotating spiral blade member.
A developing device, comprising:

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