JP2860901B2 - Developing device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dry developing device using a powder developer.

[Conventional technology]

2. Description of the Related Art In an image forming apparatus such as a copying machine, a facsimile, and a printer, a dry-type developing device is widely used as a type in which an electrostatic latent image is formed on a latent image carrier and is visualized.

FIG. 9 shows a conventional example, in which a two-component developer having a toner and a carrier is accommodated in a developing container 102 of a unitized developing device 101 in this example. The developer is stirred by the rotation of the agitator 103, the paddle roll 104, and the like, and the stirred developer is supplied to the cylindrical sleeve-shaped developer carrying member 105 while being pumped up by the latter paddle roller 104. The developer carrying member 105 is also referred to as a developing roller or a developing sleeve as an example of a constituent body, and a magnet 106 is disposed inside the developer carrying member 105. The developer supplied to the developer carrying member 105 is transported around the peripheral surface while being carried on the peripheral surface. Note that, in this example, the magnet body 106 is held in a non-rotating state, the developer carrying member 105 is driven to rotate in the direction of the arrow shown in the drawing, and at the same time, the carrying developer is transported in the same direction. Has become.

Excess developer is scraped off at the doctor blade 107 of the developer carried around the developer carrying member 105, and is regulated to a fixed amount. The regulated developer is transported while being continuously carried on the developer carrying member 105. When the developer is transported near the main pole Pm of the magnet 106, the main pole P
It becomes brush-like by the magnetic force of m. That is, a magnetic brush of the developer is formed.

On the other hand, a drum-shaped photoconductor 100, which is an example of a latent image carrier, is driven to rotate in the direction of an arrow, and an electrostatic latent image is formed on the surface of the photoconductor 100 by a latent image forming unit (not shown). The photoconductor 100 passes through the magnetic brush formed by the main pole Pm as described above, and at this time, the brush is rubbed against the electrostatic latent image on the photoconductor 100, and the toner in the developer constituting the brush is removed. Electrostatically shifts to an electrostatic latent image,
The electrostatic latent image is developed and visualized. Note that the developer scraped off at the doctor blade 107 is the current plate 1
Guided to 08, through this part paddle roller 104
Returned to.

In such a developing device, the developer, particularly the toner, is easily scattered from the gap between the casing end 102a of the developing container 102 and the photoconductor 100, and there is a possibility that the outside of the developing device may be stained with the toner. . In order to eliminate such inconvenience, a seal member or the like may be provided in such a gap, but if such a member is provided,
The visible image formed on the photoconductor 101 may be disturbed by the seal member. From such a point, a gap always exists between the casing end portion 102a and the photoconductor 100, and the toner scatters from the gap.

Therefore, conventionally, as shown in FIG. 10, a forced air suction device 109 having a suction fan 110, a filter member 111, and the like is provided at a lower portion of the developing device so that the toner to be scattered is sucked by the suction device. Guide member 11 inside
Measures have been taken to ensure that they are collected in 1. However, if such a suction device is provided, the developing device becomes large, and at the same time, a dedicated suction fan is required.
There were problems such as an increase in equipment cost.

[Problems to be solved by the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a developing device which eliminates the above-mentioned conventional drawbacks and can prevent the developer from being scattered from the developing device with a very simple configuration without increasing the size of the device.

[Means for solving the problem]

In order to achieve the above object, the present invention provides a developer carrying member that carries a developer for visualizing an electrostatic latent image formed on a latent image carrier on a peripheral surface thereof, and a developer. And a developer stirring and pumping rotary member that pumps up the developer in the developer container and stirs and supplies the developer to the developer carrying member in the developing device. A plate member provided at the end is provided with a fin that rotates integrally with the developer stirring pumping rotary member, and is provided at each axial end of the developer stirring pumping rotary member from between the latent image carrier and the developer carrying member. An airflow guide for forming an airflow directed to a portion between each of the plate members and the developing container wall facing the plate members in cooperation with the rotating fins is provided, and air in the developing container is removed. In order to discharge to the outside, Suggest developing apparatus is characterized in that a filter in the opening formed in the container.

〔Example〕

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

In FIG. 1, reference numeral 10 denotes a drum-shaped photoconductor as an example of a latent image carrier, 1 denotes a unitized developing device, 2 denotes a developing container for accommodating a developer, 3 denotes an agitator, and 5 denotes the photoconductor 10 A developer carrying member for carrying a developer for visualizing the electrostatic latent image formed on the latent image carrier formed of the developer carrying member on a peripheral surface thereof, 6 is a magnet body, 7 is a doctor blade, 8 is Rectifier plates are shown, respectively, which are the photoconductor 10 of the prior art shown in FIG.
0, developing device 101, developing container 102, agitator 103, developer carrying member 105, magnet body 106, doctor blade 107, rectifying plate 1
08, respectively, and a description of the function of each member will be omitted here.

Reference numeral 4 denotes a rotary member for stirring and pumping up the developer, which corresponds to the paddle roller 104 of the conventional developing device shown in FIG. 9, and as shown in FIG.
Has stirring pumping vanes arranged at equal pitch in the circumferential direction
The rotation member 4 agitates and pumps up the developer inside the developing container 2 and supplies it to the developer carrying member 5 by the rotation.

Disc-like plate members 13, 13 provided at each end in the axial direction of the developer stirring and pumping rotary member 4 are respectively provided with agent scraping protrusions 14 at four locations on the outside. Further, a plurality of (eight in this example) fins 15 are provided at equal intervals in the circumferential direction on the inner side. The distance between the two plate members 13, 13 is substantially equal to the axial length of the magnet body 6, and the two members are in a positional relationship substantially coincident with each other in the axial direction.

The rotating shaft 4a of the developer stirring and pumping rotary member 4 is provided on the casing wall of the developing container 2, as shown in FIG.
It is rotatably supported by a side wall portion (hereinafter, referred to as a side wall portion) 2b via a bearing 16. Fins inside the side wall 2b
An airflow guide 2c is provided so as to surround 15 and, in the present example, is formed integrally with the side wall 2b. This airflow guide
The guide 2c may be fixed to the side wall 2b by screwing the guide 2c as a separate member from the side wall 2b.

In FIG. 1, when the developer agitating and pumping rotary member 4 for supplying the developer to the developer carrying member 5 together with the developer carrying member 5 is driven to rotate in the direction indicated by the arrow, the fins 15 also rotate integrally therewith. Then, an airflow is generated from between the photoconductor 10 and the developer carrying member 5 toward the inside of the developing container 2. That is, the rotation of the developer stirring and pumping rotary member 4 causes a negative pressure in the internal region of the airflow guide 2c, so that the pressure between the photosensitive member 10 and the developer carrying member 5, more specifically, the casing end
2a, the lower portion of the developer carrying member 5 and the developing container 2
An airflow is generated between the airflow guide 2c and the lower casing portion. The thick white arrow indicates the direction of this flow. For this reason, with respect to the airflow guide 2c, the portion facing the lower right side of the developer carrying member 5 in the drawing is opened.

As shown in FIG. 3, four openings 2d are formed in the side wall 2b at equal intervals around the axis 4a in this example.
A filter 17 is inserted in 2d. The air that has flowed into the airflow guide 2c passes through the filter 17 provided in the opening 2d, and flows out to the developing device. At this time, the developer in the developing container that flies along with the airflow is collected at the filters 17 arranged as shown in FIG.

As described above, in the developing device 1 of the present embodiment, the plate members 1 provided at each axial end of the developer stirring / pumping rotary member 4 are provided.
Fins 15 that rotate integrally with the rotating member 4 for stirring and pumping the developer are provided at 3,13. Then, the illustrated developing device 1
Is provided with an airflow guide c. The guide 2c cooperates with the rotating fins 15 to lift the developer agitating and rotating member from between the latent image carrier including the photoconductor 10 and the developer carrier 5. 4, each plate member 13, 13 provided at each axial end,
An airflow is formed toward the portion between the developing container wall portion, ie, the side wall portion 2b, which faces each of them. Further, in order to discharge the air in the developing container 2 to the outside, the developing container 2
The filter 17 is provided in the opening 2d formed in the developing container 2, and the air in the developing container 2 flows out through the filter 17.

By configuring the developing device as described above, the developer to be scattered can be carried on the above-described airflow, and the scattering of the toner from between the casing end 2a and the photoconductor 10 is prevented or greatly reduced. Is done.

Moreover, in this example, the fins and the like are provided by skillfully utilizing the dead space between the end portion of the developer stirring and pumping rotary member 4 and the side wall 2d. Absent. Further, since no means for exclusively driving the fins is required, the configuration is greatly simplified, which is extremely advantageous in terms of cost and power saving.

It is to be noted that the agent scraping projection 14 shown in FIG. 1 rotates integrally with the developer stirring and pumping rotary member 4, and at this time, the plate member 13
(FIG. 2) and the developer accumulated between the side wall 2b (FIG. 3) is transported to the agitator 3. As a result, the developer can be effectively used, and the overflow of the developer from the site can be prevented.

FIG. 5 shows another embodiment of the present invention. The basic configuration is the same as that of the conventional example shown in FIG. 9, and the description of the basic configuration is omitted.

As shown in FIGS. 6 and 7, a developer stirring pumping rotary member 24 provided between the developer carrying member 5 and the agitator 3 is similar to the developer stirring pumping rotary member of the previous embodiment. Fins 25 are arranged at substantially equal intervals in the circumferential direction on a disk-shaped plate member 23 provided with stirring and pumping blades 22 and provided at each end thereof. Rotating member for developing and stirring developer
As shown in FIG. 7, the rotating shaft 24a of the
It is rotatably supported via 6.

An airflow guide 2c 'is provided inside the side wall 2b so as to surround the fin 25, and in the present example, this is formed integrally with the side wall 2b. The airflow guide 2c 'may be a member separate from the side wall 2b, and the member 2c' may be fixed to the side wall 2b with screws.

Also in this example, the position of the stirring pumping blade 22 and the magnet body 6 in FIG.
In the portion, the developer is not sent to the developer carrying member 5 side.

In FIG. 5, the casing wall at the top of the developing container 2
An opening 29 is formed in 2e, and a filter 27 is attached here.

As in the previous embodiment, the developer stirring and pumping rotary member 24
By providing a fin 25 that rotates integrally with the developer stirring and pumping rotary member 24 on each plate member 23 provided at each end in the axial direction of An airflow toward the inside of the developing container 2 can be generated. At that time, in the example of FIG. 5, the space surrounded by the airflow guide 2c ', the plate member 23, and the side wall 2b (FIG. 7) tends to have a negative pressure due to the rotation of the developer stirring and pumping rotary member 24,
Accordingly, an airflow is generated from a lower portion of the developer carrying member 5 toward the space. Then, the airflow flowing out of the space flows upward in the developing container to the filter 27.
To the outside of the developer container. At this time, the developer in the developing container that flies on the airflow toward the filter 27 is collected by the filter 27. in this way,
Also in this embodiment, plate members 23, 23 provided at each axial end of the developer agitating and pumping rotary member 24 from between the latent image carrier composed of the photoreceptor 10 and the developer carrier 5, There is provided an airflow guide 2c 'for forming an airflow toward a region between the opposing developing container walls in cooperation with the rotating fins 25. A filter 27 is provided in an opening 29 formed in the developing container 2 so as to discharge the air in the developing container 2 to the outside. In the above-described embodiment, for allowing the air flow to pass through the inside and outside of the developing container
Although the opening provided with the filter is provided on the side of the side wall portion 2b, in the present embodiment, it is provided on the side of the upper casing wall of the developing container. In order to guide the airflow in such a direction, the airflow guide 2c 'is shaped as shown in FIG.

In any case, since such an airflow is formed in the developing device, the scattering of the developer as described above can be prevented or greatly reduced. Also in this embodiment, a forced air suction device as indicated by reference numeral 109 in FIG. 10 is not required. The fins 25 shown in FIG. 5 also serve to feed the developer accumulated in the lower space between the plate member 23 and the side wall 2b (FIG. 7) to the agitator 3 side. As a result, the developer can be effectively used in the present embodiment, and the developer can be prevented from overflowing from the space.

As shown in FIG. 8, the fins 25 'provided on the disk-shaped plate member 23 may be oriented as shown in the figure.

The present invention is applicable not only to a developing device using a two-component developer but also to a developing device using a one-component developer.

〔The invention's effect〕

According to the present invention, it is possible to prevent or significantly reduce the scattering of the developer from the space between the developer carrying member and the latent image carrier to the outside of the developing device, without increasing the size of the developing device. In addition, it can be realized with an extremely simple configuration while suppressing an increase in cost.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a developing device according to one embodiment of the present invention, and FIG.
FIG. 3 is a perspective view of a developer stirring pumping rotary member provided in the developing device, FIG. 3 is a diagram showing an end of the developer stirring pumping rotary member, FIG. 4 is a diagram showing an arrangement positional relationship of a filter, FIG. 5 is a schematic cross-sectional view of a developing device of another embodiment, FIG. 6 is a perspective view of a developer stirring pumping rotary member provided in the developing device, and FIG. 7 is an end of the developer stirring pumping rotary member of the developing device. , FIG. 8 is a diagram showing another fin configuration, FIG. 9 is a schematic sectional view of an example of a conventional developing device, and FIG. 10 is a schematic sectional view of another example of a conventional developing device. 2, a developing container, 2d, 29, an opening 4, 24, a rotating member for pumping and stirring the developer, a developer member 13, 23, a plate member, 15, 25, 25 ', a fin, 17,27 …… Filter

Claims (1)

(57) [Claims] A developer carrying member for carrying a developer for visualizing an electrostatic latent image formed on the latent image carrier on a peripheral surface thereof; and a developing container for containing the developer. A developer stirring and pumping rotary member for pumping the developer in the developer container while stirring and supplying the developer to the developer carrying member, wherein a plate provided at each axial end of the developer stirring and pumping rotary member is provided. A fin that rotates integrally with the developer stirring pumping rotary member is provided on the member, and between the latent image carrier and the developer carrying member, each plate member provided at each axial end of the developer stirring pumping rotary member, An airflow guide for forming an airflow toward a region between the opposing developer container wall portions in cooperation with the rotating fins is provided,
A developing device, wherein a filter is provided in an opening formed in the developing container so as to discharge air in the developing container to the outside.