JPH07244425A - Developer stirring/mixing device for two component developing device - Google Patents

Abstract

PURPOSE:To provide a compact and inexpensive developer stirring/mixing device for a two-component developing device, capable of being composed of a smallest number of parts without deteriorating performance for horizontally stirring a developer. CONSTITUTION:The developer stirring/mixing device is provided with a paddle 31 provided on the outer periphery of a rotary hollow cylinder 27, an outside spiral rib 32 spirally formed along the outer periphery of the cylinder 27 to cross the paddle 31, an inside spiral rib 33 formed to a spiral shape opposite to that of the outside spiral rib 32 along the inner periphery of the cylinder 27 and rear and front side openings 36 and 37 which are provided on both ends of the cylinder 27 and can make the developer flow out and in.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an agitating / mixing device for a two-component developing device in copying machines, printers and the like.

[0002]

2. Description of the Related Art Conventionally, a paddle and an outer spiral rib are provided on the outside of a cylinder, and a screw as a separate component is provided on the inside of the cylinder. There has been proposed a two-component developing device agitating and mixing device configured to agitate the toner in the lateral direction (JP-A-62-19883).

In this agent stirring and mixing apparatus, the spiral ribs provided on the outer side of the cylinder are driven to rotate, and the screw provided on the inner side of the cylinder is also driven to rotate, so that the lateral stirring performance of the developer is high.

This agent stirring and mixing apparatus can perform all the functions required for a two-component developing apparatus, that is, stirring of the developer, scooping of the developer, and lateral stirring of the developer with a single roller. Since it can be made compact, it has been put to practical use especially in a developing device of a full-color copying machine which requires small size and highly efficient stirring. In a full-color copying machine which requires 3 to 4 developing units, the lateral agitation performance of the developer is likely to be deteriorated due to downsizing of the apparatus.

[0005]

By the way, in the two-component developing device of a full-color copying machine, the difference in the density of the developer in the lateral direction immediately appears as a non-uniform development color. On the other hand, a single-color copying machine does not require the lateral stirring performance of the developer as much as a full-car copying machine, and in such a mono-color (mostly black) copying machine, the driving of the developing device is rather complicated. This raises the cost and increases the size of the device body in the depth direction.

That is, in this type of developing device, the number of agitating devices for the developer in the device is particularly reduced, and one agitating roller has both functions of conveying the developer and agitating in the lateral (width) direction. However, when the agitating roller is made to have such a structure, the structure of the agitating roller becomes complicated, and the drive system of its constituent parts also becomes complicated, resulting in difficulty in manufacturing and a cost increase.

The present invention has been made in view of the above-mentioned points, and an object thereof is a compact and low-priced type 2 which can be constituted by a minimum number of parts without deteriorating the lateral stirring performance of the developer. An object is to provide an agent stirring and mixing device for a component developing device.

[0008]

In order to solve the above-mentioned problems, the present invention provides, in claim 1, an agent stirring and mixing apparatus for stirring and mixing the developers of a two-component developing apparatus, which comprises a rotating hollow. The paddle provided on the outer periphery of the cylindrical body, the first rib spirally formed along the outer peripheral surface of the cylinder so as to cross the paddle, and the first rib opposite the inner peripheral surface of the cylinder. Direction second spiral ribs, and holes provided at both ends of the cylinder for allowing the developer to flow in and out.

According to a second aspect of the present invention, there is provided an agent stirring and mixing device for stirring and mixing the developer of the two-component developing device, wherein the first rib is formed in a spiral shape along the outer peripheral surface of the rotating hollow cylindrical body. And second ribs formed in a spiral shape in a direction opposite to the first ribs along the inner peripheral surface of the cylinder, and holes provided at both ends of the cylinder for allowing the developer to come in and out. The configuration.

According to a third aspect of the present invention, there is provided a two-component developing apparatus, wherein the agent agitating and mixing device is a mixing / mixing device.
In the vicinity of the hole provided on the developer inlet side in the developer conveying direction by the spiral second rib provided on the inner circumference of the cylinder,
A toner supply port for supplying toner is provided.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a schematic configuration of an image forming apparatus of a copying machine equipped with the agent stirring and mixing apparatus of the two-component developing apparatus of the present invention.

In FIG. 1, the photosensitive drum 1 is charged by contact with a charging roller 2 which rotates as it rotates clockwise, and a latent image is formed by an exposure image 3 from an exposure device (not shown). The latent image formed on the photosensitive drum 1 is
A toner image is formed by the developer supplied from the developing device 4. To the developing device 4, in order to always maintain a proper developer concentration, an amount of toner corresponding to the toner consumption amount due to latent image formation is replenished from the toner cartridge 5 at appropriate times.

On the other hand, while the toner image formation on the photosensitive drum 1 is in progress, the paper P whose timing is adjusted by the registration roller 6 is fed between the photosensitive drum 1 and the transfer roller 7. . The sheet P is transferred to the fixing device 10 by the transfer belt 9 after the toner image formed on the photosensitive drum 1 is transferred by the action of the transfer roller 7. The paper P on which the toner image is fixed by the fixing device 10 and the copy is completed is ejected by the paper ejection roller 11 onto a paper ejection tray of the main body of the copying machine (not shown).

2 and 3 show an embodiment of an image forming apparatus to which the present invention is applied. In FIG. 2, 20 is a developing device main body, and 30 is a stirring roller which is a component to which the present invention is applied. This agitating roller 30 is a paddle 2.
1, the outer spiral rib 25, the inner spiral rib 26, and
It is composed of a cylindrical body 27 and the like. This stirring roller 3
0 will be described in detail in FIGS. 4 and 5 described later.

In FIG. 2, the developing roller 22 sends the developer drawn up by the agitating roller 30 to the developing section (the surface of the photosensitive drum 1), and at the same time forms a magnetic brush on the peripheral surface thereof, and further develops it. The developer which has been completed is returned to the lower part of the stirring roller 30 for reuse. Doctor 23
Serves to make the amount of the developer sent to the developing section by the developing roller 22 constant, and the excess developer scraped off by the doctor 23 is returned to the stirring roller 30 by the separator 24.

On the other hand, the residual toner supplied to the photosensitive drum 1 by the developing roller 22 and not transferred onto the sheet P by the transfer roller 7 is scraped off from the photosensitive drum 1 by the cleaning blade 12, It is stored in a collection container (not shown) by the collection toner transport roller 13.

FIG. 3 is a plan view of the above-described image forming apparatus. In FIG. 3, the toner in the toner cartridge 5 is replenished through the opening 35 as needed. In this embodiment, the toner from the opening 35 is replenished to the inner end of the stirring roller 30, and the stirring roller 30 mixes and stirs with the carrier in the developer. To be contributed to the development. The collected toner conveying roller 13 shown in FIG. 3 is not directly related to the present invention, but as described above, conveys the toner cleaned by the cleaning blade 12 and scraped off from the photosensitive drum 1 into the collecting container. To do.

Further, as shown in FIG.
The cylindrical body 27 is provided with two holes, a back side opening 36 and a front side opening 37, respectively.
6, 37 to receive the developer in the cylindrical body 27,
A passage is formed for laterally stirring the developer in the developing device. For lateral stirring of this developer, see FIG.
And FIG. 5 will be described in detail.

FIG. 4 shows a concrete construction of the stirring roller 30 which is the first embodiment of the agent stirring and mixing apparatus of the two-component developing apparatus according to the present invention. In FIG. 4, the paddle 31, like the paddle 21 described above, has a function of pumping up the developer in the container of the developing device. Also, the outer spiral rib 32
Like the outer spiral rib 25 described above, is provided across the paddle 31 over substantially the entire width of the cylindrical body 27.

The inner spiral rib 33 is provided on the cylindrical body 27, and like the outer spiral rib 32, is provided over substantially the entire width of the cylindrical body 27. However, the inner spiral rib 33 is formed such that the spiral direction thereof is opposite to the spiral direction of the outer spiral rib 32.

Although the drive shaft 38 and the support shaft 39 of the stirring roller 30 are integrally fixed to the cylindrical body 27,
In FIG. 4 and FIG. 5, the structure of the stirring roller 30 is shown separately from the cylindrical body 27 in order to make it easy to understand.

In the present embodiment, in FIG. 4, when the drive shaft 38 of the stirring roller 30 is rotated in a predetermined rotation direction (arrow direction), the developer in the developing device container is forced to move to the outside spiral rib 3.
By the action of 2, the toner is moved in the front direction indicated by the arrow A and in the back direction indicated by the arrow B by the inner spiral rib 33, and the one stirring roller 30 stirs the developer in the lateral direction. At this time, the inner diameter and the outer diameter of the cylindrical body 27, the spiral pitch P of the inner and outer spiral ribs 32 and 33, the twist angle θ, or the size of the openings 36 and 37 are prevented so that the developer is not biased. And the like are set to predetermined values.

FIG. 5 shows a concrete structure of a stirring roller 30 which is a second embodiment of the agent stirring and mixing device of the two-component developing device according to the present invention. The stirring roller 30 of this embodiment has substantially the same configuration as that of the first embodiment except that the paddle 31 of the stirring roller of the first embodiment is removed.
The present embodiment is characterized in that the outer spiral rib 32 has a developer scooping function, which is the function of the paddle 31 in the stirring roller of the first embodiment. That is,
According to this embodiment, as described in the first embodiment,
The spiral pitch P of the outer spiral rib 32 and the twist angle θ
Is set to an appropriate value, the developer can be pumped up only by the outer spiral rib 32 without providing the paddle 31.

By the way, the stirring roller 30 of each of the above-mentioned embodiments
When actually mass producing, its rotation axis (rotation center line)
It is composed of a pair of resin parts that are divided in two by the surface passing through,
Alternatively, the inner spiral rib 33 on the inner circumference of the cylindrical body 27 is formed as a separate component from the cylindrical body 27, and the inner spiral rib 33 is formed.
It is possible to adopt a method such as assembling by inserting and fixing into the cylindrical body 27. By configuring the stirring roller by such a method, particularly when the stirring roller is made of resin parts, the number of constituent parts can be minimized, and the stirring roller can be provided easily and at low cost.

On the other hand, in each of the above embodiments, the cylindrical body 27
A toner replenishing port for replenishing toner is provided near the front side opening 37 provided on the developer inlet side in the developer conveying direction by the inner spiral rib 33 provided on the inner periphery of As a result, the developer can be made uniform. That is, in this structure, the opening 35 for replenishing the toner of the toner cartridge 5 shown in FIG. 3 is located at the edge of the front side opening 37 of the cylindrical body 27. Therefore, in this configuration, the toner replenished from the toner cartridge 5 is mixed and stirred by the inner spiral rib 33 and then discharged from the back side opening 36 and sent to the developing section, so that the developer can be made uniform.

[0026]

As described above, according to the first aspect of the present invention.
According to this, since the inner spiral rib is fixedly provided on the inner circumference of the cylindrical body, the component shape can be simplified and the driving device thereof can be configured simply and at low cost as compared with the conventional example.

According to the second aspect of the invention, it is possible to provide a device including the driving device for pumping the developer and laterally stirring the developer in one component, at a small size and at low cost.

According to the third aspect of the invention, the opening for replenishing the toner of the toner cartridge is located at the edge of the front side opening of the cylindrical body, and the toner replenished from the toner cartridge is the inner spiral rib. After being mixed and stirred, the mixture is discharged from the opening on the inner side and sent to the developing section, so that the developer can be made uniform, the amount of free toner can be reduced, and the scattering of toner can be reduced.

[Brief description of drawings]

FIG. 1 is a side view showing a schematic configuration of an image forming apparatus of a copying machine equipped with a two-component developing apparatus agent stirring and mixing apparatus of the present invention.

FIG. 2 is a side view of the embodiment of the image forming apparatus to which the present invention is applied.

FIG. 3 is a plan view of an embodiment of an image forming apparatus to which the present invention has been applied.

FIG. 4 is a perspective view of a first embodiment of the agent stirring and mixing device of the two-component developing device according to the present invention.

FIG. 5 is a perspective view of an essential part of a second embodiment of the agent agitation mixing device of the two-component developing device according to the present invention.

[Explanation of symbols]

 4 Developing Device 5 Toner Cartridge 20 Developing Device Main Body 22 Developing Roller 23 Doctor 24 Separator 27 Cylindrical Body 30 Stirring Roller 31 Paddle 32 Outer Spiral Rib 33 Inner Spiral Rib 35 Opening 36 Rear Side Opening 37 Front Side Opening 38 Drive Shaft 39 Supporting Shaft

Claims (3)

[Claims] 1. A developer agitation mixing device for agitating and mixing a developer of a two-component developing device, comprising a paddle provided on the outer periphery of a rotating hollow cylindrical body and an outer peripheral surface of the cylinder so as to cross the paddle. Spirally formed first ribs, second ribs spirally formed along the inner peripheral surface of the cylinder in the direction opposite to the first ribs, and a developer provided at both ends of the cylinder. And a hole for allowing the entry and exit of the agent, and a stirring and mixing device for a two-component developing device. 2. An agent stirring and mixing device for stirring and mixing the developer of a two-component developing device, comprising: a first rib formed in a spiral shape along the outer peripheral surface of a rotating hollow cylindrical body; It is characterized by having a second rib formed in a spiral shape in a direction opposite to the first rib along a peripheral surface, and holes provided at both ends of the cylinder for allowing the developer to come in and out. Mixing agent mixing device for two-component developing device. 3. The agent stirring and mixing device for a two-component developing device according to claim 1 or 2, wherein an inlet of the developer in a developer conveying direction is provided by a spiral second rib provided on the inner circumference of the cylinder. A toner agitation mixing device for a two-component developing device, characterized in that a toner replenishing port for replenishing toner is provided in the vicinity of the hole provided on the side.