JPH07219347A - Developing device - Google Patents

Abstract

PURPOSE:To provide a developing device capable of miniaturizing a developing means constituted so as to face an electrostatic latent image carrier, simplifying the constitution and improving operability at the time of maintenance. CONSTITUTION:The developing device is provided with a developer optimizing unit 500 composed of a developer optimizing means 100 optimizing a developer and a developer transferring/circulating means 200 transferring the optimized developer to the developing means and the remainder of the developer supplied to develop to the developer optimizing means and the developing means 10 is provided with a developer supplying member, a developer layer regulating member, a developer recovering member recovering a part of the developer, a stirring member stirring the remaining developer recovered by the developer recovering member, the developer from the developer optimizing means and the remainder of the developer supplied to the electrostatic latent image carrier by a developing sleeve and transferring the stirred developer to the developing sleeve, an entrance for receiving the optimized developer and an exit for feeding the recovered developer to the developer optimizing means 1000.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing device in an image forming apparatus using electrophotography, and more particularly to a developing device applicable to a printer, a facsimile, a copying machine or the like for developing using a two-component developer. Is.

[0002]

2. Description of the Related Art
As a technique relating to a developing device having a developing means for applying a two-component developer, which is a mixture of toner and carrier, to the electrostatic latent image carrier to develop the electrostatic latent image on the electrostatic latent image carrier. There are the following:

.. A developing device using a two-component developer, which has a developer stirring means inside the photosensitive drum and is connected to a developing device by a pipe to circulate the developer (see Japanese Patent Publication No. 5-21082). ).

.. The developer or the carrier is supplied to the developing container, at the same time, the same amount of the developer is discharged, and the toner consumed by the development is detected by the volume detecting means to supply the toner,
A technique for easily maintaining a constant developer concentration in a developing container (see Japanese Patent Publication No. 60-18065).

.. A technique for detecting the developer concentration by a change in volume (see Japanese Patent Application Laid-Open No. 50-19459).

[0006] A developing unit and means for supplying a fixed amount of carrier to the developing unit according to a predetermined developing time or a predetermined copy amount;
Development including detection means for detecting a change in the ratio of carrier and toner in the developer and issuing a signal, means for supplying the toner to the development portion in response to the signal, and means for discharging a predetermined amount or more of the developer in the development portion Device technology (Japanese Patent Laid-Open No. 51-13
249).

[0007]. A technique relating to extending the life of the developer by supplying the additional developer including the toner and the carrier to the developer in the developing device (Japanese Patent Laid-Open No. 4-3538).
No. 81).

[0008]

In the conventional developing device,
In the vicinity of the developing sleeve, there is a reservoir portion for storing the developer to supply the developer to the developing sleeve provided opposite to the photoconductor as the electrostatic latent image carrier, and a tank for replenishing the toner. Since it is integrally formed with the developing means configured as a unit containing a sleeve, there is a problem that the constituent portion becomes large, the device configuration becomes complicated, and the operability at the time of device maintenance is deteriorated. .

Therefore, according to the present invention, the developing means constituted so as to be opposed to the electrostatic latent image carrier is downsized and the structure is simplified.
It is an object of the present invention to provide a developing device capable of improving operability during maintenance.

[0010]

The invention according to claim 1 is
The developer, which is disposed so as to face the electrostatic latent image bearing member and rotates in the same direction at the portion facing the electrostatic latent image bearing member, mixes toner and carrier to the electrostatic latent image bearing member. In a developing device having a developing means having a developing sleeve for developing the electrostatic latent image on the electrostatic latent image carrier,
A developer optimization unit that is configured as a unit separate from the developing unit, is disposed at a position different from that of the developing unit, and optimizes the concentration and charge amount of the developer, and the development optimized for the developing unit. A developer optimization unit comprising a developer transfer / circulation unit that transfers the developer and transfers the remaining excess developer applied to the development from the development unit to the developer optimization unit; The developing means includes a developer supplying member that supplies a developer to the developing sleeve,
A developer layer regulating member arranged between the developer supplying member and the developing position, and a developer collecting member for collecting a part of the excess developer scraped off by the developer layer regulating member,
The remaining developer recovered by the developer recovery member,
An agitating member for agitating the developer from the developer optimizing means and the remaining developer applied to the electrostatic latent image bearing member by the developing sleeve and transferring the agitated member to the developing sleeve; An inlet for receiving the developer optimized by the optimization means and an outlet for sending the developer collected by the developer recovery member to the developer optimization means are provided.

According to a second aspect of the invention, in the developing device according to the first aspect, the developer supply member is provided between the developer layer regulating member and the stirring member.

According to a third aspect of the invention, in the developing device according to the first aspect, a plurality of the developing sleeves are provided.

According to a fourth aspect of the invention, in the developing device according to the first aspect, a plurality of the developing sleeves are provided, and the developer supplying member supplies the developer only to one of the developing sleeves. I decided.

According to a fifth aspect of the present invention, in the developing device according to the third aspect, the number of the developing sleeves is two, the number of the developer supplying members is one, and the developer supplying member is one of the developing sleeves. Of these, the developer is supplied to the developing sleeve that first develops the electrostatic latent image.

According to a sixth aspect of the present invention, in the developing device according to the first aspect, a plurality of developing means are provided radially with respect to the central axis of rotation, and the developing sleeve of each developing means is controlled by controlling the rotational position. Then, it is configured as a part of a rotary developing unit for sequentially developing the latent image bearing member so as to face the latent image bearing member.

According to a seventh aspect of the invention, in the developing device according to the sixth aspect, each developing means is yellow, magenta, or
It is assumed that each of the cyan and black developers is contained in one color.

[0017]

The developing means receives an appropriate supply of the developer by the developer optimizing unit which is arranged at an arbitrary position apart from the developing means and which includes the developer optimizing means and the developer transferring / circulating means. , Develop the electrostatic latent image on the electrostatic latent image carrier. A part of the surplus developer is recovered by the developer recovery member and optimized by the developer optimization means. After that, the optimized developer is agitated by the agitating member with the remaining developer recovered by the developer recovering member, and is transferred to the developing sleeve for development.

[0018]

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, reference numeral 10 is a developing means, and 500 is a developer optimizing unit. The developer optimization unit 500 is composed of a developer optimization unit 1000 and a developer transfer / circulation unit 200. The developer optimization unit 500 is configured as a unit separate from the developing unit 10, is arranged at a different position, and has a function of optimizing the developer. Further, the developer optimizing unit 500 can be provided with a toner replenishing unit for replenishing new toner. The developer is circulated between the developer optimizing means 1000 and the developing means 10. This circulation is performed by the developer transfer / circulation means 200.

The developing means 10 is a developer optimizing means 100.
Inlet 111a for receiving the developer optimized by 0
And an outlet 12 for discharging the excess developer used for development by the developing means 10 to the developer optimizing means 1000.
1a.

As the developer, a two-component developer composed of toner and carrier is used. Optimizing the developer includes adjusting the mixing ratio of the toner and the carrier to optimize the agent concentration and the charge amount of the agent. Further, the foreign matter such as paper powder mixed in the agent is removed by the foreign matter removing means in the circulation process. The developer optimization unit 1000 is a toner replenishment unit,
A toner and carrier stirring member and a concentration sensor as a developer concentration detecting means are provided. It should be noted that the foreign matter removing means or the like may be attached. The developing means 10 is a dry type and uses a two-component developer, and adopts a magnetic brush developing method, but it is also possible to adopt a cascade developing method.

The developer optimizing means 1000 is the developing means 1
Since it is arranged at a position different from 0, the two are connected via the developer transfer / circulation means 200. Since the developer transfer / circulation means 200 has a function of circulating the developer between them, the developer optimizing means 10
00 and the inlet 111a, a supply path (the upward arrow path in FIG. 1), a discharge path (the downward arrow path in FIG. 1) connecting the developer optimizing means 1000 and the outlet 121a, and these developing means. 10, developer optimizing means 10
00, a supply path, and a discharge path, and a developer transfer pump and a foreign matter removing means provided at an arbitrary position in the developer circulation path.

The developer passing through the supply path is a developer whose developer concentration and charge amount have been optimized by the developer optimizing means 1000, and the developer passing through the discharge path is the developing means 10.
It is a surplus developer provided for development by and is a developer before being optimized. The supply passage and the discharge passage are configured by pipes. The developer transfer pump is constituted by a powder transfer screw pump, and the pump can be incorporated in the developer optimizing means.

In FIG. 2, reference numeral 1 denotes a photosensitive drum in which the electrostatic latent image carrier is drum-shaped. The photoconductor may be formed in a belt shape instead of the drum. An electrostatic latent image is formed on the photoconductor drum 1 by charging and exposing by a conventionally known electrophotographic image forming process. This electrostatic latent image is visualized by the developer provided by the developing means 10 adopting the magnetic brush developing method by the well-known dry two-component developing method.

Here, the developing means 10 is a developing sleeve 1 which is a direct means for supplying a developer to the photosensitive drum 1.
00 is included, but here, the developer supply member 110, the developer collecting member 120, the developer layer restricting member 130, the passage means, and the agitator provided around the developing sleeve 100 are provided. It refers to a unit that also includes a member 170 and a case 150 that houses and holds these members.
The developing sleeve 100 has a known structure including a sleeve and a magnet provided inside the sleeve.

The developing means 10 is located around the photosensitive drum 1 which rotates in the direction of the arrow, and has an exposure position where a latent image is formed by irradiating the optical image P and a toner image which visualizes the latent image as a transfer material. The developing position between the transfer position where the transfer charger Q for transferring is provided, that is, the position where the developing sleeve 100 actually faces the photoconductor drum 1 in FIG. In, it is rotated so as to move in the same direction as the photosensitive drum 1.

The photoconductor drum 1 has a length in the direction of penetrating the paper surface of FIG. 2, and if this length direction is called the width direction of the photoconductor drum 1, an image is formed over this width direction. Therefore, the developing sleeve 100 also needs to supply the developer in the width direction, and the developing sleeve 100 is dimensioned in the width direction according to the photosensitive drum 1.

For this reason, since it is necessary to supply the developer to the developing sleeve 100 in the width direction, the developer supplying member 110 is at least the developing sleeve 100.
Covers the entire width direction of the. Developer collecting member 120
Develops a part of the surplus developer provided for development by the developing means 1
0 to the outside of the developer supply member 11
Like 0, it covers the entire width direction of the developing sleeve 100.

The agitating member 170 serves as the remaining developer recovered by the image recovering member 120 and the developer optimizing means 100.
The developer from 0 is stirred and transferred to the developing sleeve 100. Therefore, the stirring member 170 also covers the entire area of the developing sleeve 100 in the width direction similarly to the developer supply member 110 described above.

In this example, the developer supply member 110 and the developer recovery member 120 are both constructed as a transfer means using a screw, and the developer is introduced into the inlet 111a and the outlet 121a by a driving means (not shown). It is rotated to send it to the side.

The developer supplying means 110 removes the developer scraped by the developer layer regulating member 130 from the developer discharging member 120.
It is covered with a developer guide member 140 and a case member 141 as a passage means for feeding to. In the range corresponding to the width region of the developing sleeve 100 of the case member 141, the developer is supplied from the developer supplying member 110 to the developing sleeve 1.
A notch (not shown) is provided for feeding the No. 00.

The developer guide member 140 is composed of a horizontal portion 140h located above the developer supply member 110 and an inclined surface portion 140k following the horizontal portion 140h, and together with a lid 160 provided as a part of the case 150 so as to be openable and closable. It forms a certain space. This space portion forms a passage R for transferring the excess developer supplied for development to the developer discharge member 120. Therefore, these members constitute the passage means.

The developer collecting member 120 is provided below the extension of the inclined portion 140k of the guide member 140 in order to collect a part of the excess developer by using its own weight. In addition, in order to regulate the inflow amount of the excess developer into the developer recovery member 120, between the developer recovery member 120 and the inclined portion 140k, it is integrated with the case 150 so as to surround the developer recovery member 120. The formed regulation member 18
0 is provided. The regulating member 180 is the developing unit 10.
It is intended to make the amount of developer stored inside constant, to stabilize the amount of charge of the developer, and to uniformly supply the developer to the developing sleeve 100. That is, when the amount of the excess developer is large, a larger amount of the excess developer is guided to the developer collecting member 120, and when the amount of the excess developer is small, the stirring member 1
The regulating member 180 so that the excess developer is guided to
The shape and its mounting position are set. In this example, the regulation member 180 is formed integrally with the case 150, but it may of course be formed separately.

Below the developer supply member 140, the remaining developer recovered by the developer recovery member 120, the developer from the developer optimizing means 1000, and the developing sleeve 1
Agitating member 1 for agitating the remaining developer applied to the photoconductor drum 1 by 00 and transferring it to the developing sleeve 100.
70 is provided.

In FIG. 2, the developer layer regulating member 130
Is provided around the developing sleeve 100 and between the developer supply member 110 and the developing position. The developer layer restricting member 130 is what is called a doctor. The base end side of the developer layer restricting member 130 is fixed to the case 150, and the free end side of the developer layer restricting member 130 closely faces the developing sleeve 100. It has functions of scraping the developer, controlling the layer thickness, and collecting the scraped developer.

Excessive developer at the time of development rotates together with the development sleeve 100 in the direction of the arrow which is the direction of rotation of the development sleeve, and a part thereof falls onto the stirring member 170, and the other developer. Is scraped off by the developer layer regulating member 130, passes through the passage R, and is regulated in amount by the regulating member 180 to reach the developer discharging member 120.

3 and 4, in the case 150, the widthwise ends of the developing sleeve 100 are closed by side plates, and a part of the side plate 101 on one end side is provided with the developer supply member 11.
0 and the developer collecting member 120 are formed in a cylindrical shape so as to form a circular hole for accommodating the screw portion of the developer collecting member 120. Each screw of the developer supplying member 110 and the collecting member 120 is inserted into the circular hole formed in the cylindrical portion. The parts are fitted together. Further, the end shafts of the screw parts are pivotally supported by lid members 101a and 101b that close the circular holes.

An inlet 111a and an outlet 121a are provided in the middle of each of these circular holes in a direction orthogonal to the circular holes. The inlet 111a is the developer discharge port 206 of the developer optimization unit 1000 shown in FIG. 1, and the outlet 121a is
The developer inflow port 225 of the developer optimizing means is connected to the supply pipe 111 serving as a supply passage and the discharge pipe 121 serving as a discharge passage, respectively.

With this configuration, the developer optimizing means 10
The developer transferred from 00 to the developing means 10 by the supply pipe 111 is further transferred by the developer supply member 110 in parallel with the developing sleeve 100, and a notch (not shown) provided in a part of the case member 141. ) From developing sleeve 10
0 is sent to the entire surface.

This developer is used as the developer regulating member 1.
The optimum developing layer thickness is obtained by 30 and the resultant is used for development. The developer scraped off by the developer layer regulating member 130 is also a surplus developer at the time of development, and a part of this developer is formed in the space between the upper portion of the developer guide member 140 and the lid 160. And is guided to the developer discharge member 120. Further, the developer, which has been applied to the photosensitive drum 1 but has not adhered to the latent image portion, is an excess developer at the time of development and is guided to the stirring member 170.

The developer introduced to the developer discharging member 120 is discharged by the developer discharging member 120 to an outlet 121a.
Then, the toner is sent to the developer optimizing means 1000 via the discharge pipe 121.

According to the example described above, the developer supply member 1
Even if the developer supply amount in 10 varies, the stirring member 17
When 0, the charge amount of the developer can be stabilized and the developer can be uniformly supplied to the developing sleeve 100. Further, since the developer optimizing unit capable of providing the toner replenishing unit can be installed at a position different from the developing means,
Not only is the structure of the developing means very simple, but the scattering of the developer is reduced, downsizing can be achieved, the internal structure of the complicated image forming apparatus is simplified, and there is a margin in the layout. It can be facilitated. Further, the developing unit is driven by the developing sleeve and the developer supplying member 11.
0, since it is sufficient to drive the developer discharging member 120,
Power saving can also be achieved. Since the development can be always performed by the developer optimized by the developer optimizing means 1000, the development quality is high and stable, and the image quality is high and stable.

The developer optimization unit 1000 of the developer optimization unit 500 and the developer transfer / circulation unit 2 will be described below.
An example of a pump or the like as 00 will be described with reference to FIG. In FIG. 7, the developer discharged from the developing means 10 is guided to the developer optimizing means 1000 via the discharge pipe 121.

In FIG. 7, reference numeral 220 denotes a developer stirring unit, which is composed of a container 223 having a cylindrical lower portion and a funnel upper portion, and a stirring screw 221 rotated by a drive motor 222 inside the container. Has been done.

An outlet of the toner replenishing unit 230 and a developer inflow port 225 are opened in the upper portion of the agent storage container 223. The toner replenishing unit 230 is configured so that a new toner 231 can be appropriately supplied by opening the lid 230a, and a toner supply member 232 is provided so as to close the outlet provided at the lower portion thereof. This toner supply member 2
Reference numeral 32 denotes a cylindrical portion that is rotationally driven, and has a large number of cutouts formed along the rotation axis direction on the peripheral surface thereof. Toner contained in the cutouts is stored by rotation of the toner supply member 232. It has a function of supplying to the container 223.

The developer outlet 206 is located below the developer optimizing means 1000.
A developer concentration detection member 240 is provided in the middle of the developer passage 270 near 06, and the toner supply member 232 is rotated by a signal from a conventionally known developer concentration detection control circuit (not shown), and the toner supply member 232 is rotated. The toner in the replenishing unit 230 is supplied into the agent storage container 223.

In this way, the new toner that is replenished while being controlled by the toner replenishing unit 230 is added to the developer discharged from the developing means 10, and the developer stirring unit 2
At 20, the developer concentration and the charge amount are optimized so as to satisfy the optimum conditions for development.

The developer thus optimized is sent to the powder pump unit 200 located below the developer stirring unit 220. The powder pump unit 200 is configured by a screw pump (commonly known as MONO pump, conventionally known).

This pump is based on the above-mentioned drive motor 222.
And rotor 2 connected via a stirring screw 221
01 and rotor 2 made of elastic material such as rubber material
01 is provided, an upper pump holder 203u that holds this state, a lower pump holder 203d, and the like. The upper pump holder 203u connects the powder pump unit 200 and the developer stirring unit 220. .

As described above, the developer passage 270 is provided in the lower portion of the lower pump holder 203d, and the outlet of the screw pump and the developer discharge port 206 communicate with each other through the passage 270. . This developer passage 2
A lower air supply port 205 is provided at a position above 70 and near the lower end of the rotor 201, that is, the outlet of the screw pump. The lower air supply port 205 communicates with the developer passage 270.

On the other hand, at a position on the upper pump holder 203u near the inlet of the powder pump unit 200,
An upper air supply port 204 communicating with the agent storage container 223 is provided. The outer sides of the upper air supply port 204 and the lower air supply port 205 are respectively provided with two air discharge ports 208 provided in a part of a fan case accommodating a fan 207 rotated by a drive motor 222 and a pipe. Communicate with each other.

When the drive motor 222 rotates, the fan 207 draws in air from the outside, and the upper air supply port 204
And air is blown into the developer through the lower air supply port 205. This promotes fluidization of the developer, and ensures more reliable transfer with the screw pump. The amount of air supplied is very small, and after contributing to the transfer of the developer,
It escapes from the gap of the developing means 10 to the outside. In the example shown in FIG. 5, the fan 207 is mounted coaxially with the drive motor 222, but without such a configuration, a separate pump is provided and air is supplied to the upper and lower air supply ports 204 and 205. It is also possible to supply.

The developer having passed through the powder pump unit 200 has its developer concentration detected by the developer concentration detecting member 240, is discharged from the developer discharge port 206, and is supplied to the supply pipe 11.
1 to the developing means 10.

In this example, as shown in FIG. 2, the developer optimizing unit 500 is located below the developing means 10, so that a pump force is applied from the developer optimizing unit 500 to the developing means 10. Although the developer cannot be sent out without using, the pump means is unnecessary because the developer is transferred from the developing means 10 to the developer optimizing unit 500 by using gravity.

When the positional relationship between the developing means 10 and the developer optimizing unit 500 is opposite to that described above, or when the developing means 10 and the developer optimizing unit 500 are arranged at substantially the same height, the developer transfer force should be obtained. , Install appropriate pumps in the circulation route.

Developing means 10 and developer optimizing means 1000
Between, for example, in the middle of the discharge pipe 121 or the supply pipe 11
In the middle of 1, it is effective to improve the development quality by providing a removing means for removing foreign matter mixed in the developer, for example, paper dust. As the removing means, a filter, electrostatic adsorption, centrifugal separation or the like is appropriately selected and employed.

The known screw pump called a MONO pump used in this example is of a rotary positive displacement type and is of a pressure-transfer type. Since it is transferred at a high solid-gas ratio by extremely small air, The developing agent fills the supply pipe 111 and flows continuously. Therefore, it is possible to control the flow rate with high quantitativeness and high accuracy of continuous transfer, and the transfer air to be used is a very small amount of air to maintain the fluidized state of the powder and the uniform flow state over the entire length of the transfer line. The amount is enough.
Furthermore, since it is a low-speed, high-concentration transfer, there is no crushing of powder, only a small diameter pipe is required, there is no trouble of transfer pipe wear, there is little noise, and the structure is simple, economical and reliable. It has features such as excellent maintainability.

In the above developing device, when the carrier deteriorates due to long-term use, it is necessary to remove all the developer from the developing device. In that case, the developer in each unit should be emptied. Then, the discharge pipe 121 is removed from the developer optimizing means 1000, the end of the discharge pipe 121 is connected to the recovery container, and the drive motor 222 is driven. As a result, all the developer including the deteriorated carrier is stored in the recovery container. The developer contained in the collection container can be appropriately disposed of, such as discarded or reused. If the work of accommodating in the recovery container is performed also during maintenance such as replacement and repair of various members, there is no developer remaining in the various members, so that the developer is not scattered and the workability in the above maintenance is improved.

In this way, the work efficiency is greatly improved as compared with the conventional method in which the entire developing device is detached from the machine main body, and the developing device is disassembled to collect the agent manually. Can be achieved.

According to the developer optimizing means 1000 of this example, since the storage capacity of the developer is determined by the capacity of the agent storage container 223, it is necessary to make the developer replacement interval very long due to agent fatigue and the like. This is possible by enlarging the agent storage container 223.

Further, the developer optimizing means 1000 is unitized as a separate body from the developing means 10, and the supply pipe 11 is provided.
1. Since they are only connected by the discharge pipe 121, restrictions on the installation place are reduced, and economical agent storage capacity is ensured, operation quality of agent exchange, productivity of assembly and adjustment, etc. Excel. Since the degree of freedom in layout is expanded in this way, the toner replenishing unit 230 can also be arranged at a position where the user can easily perform the toner replenishing operation, and similar advantages can be obtained.

The toner replenishing unit 230 can further improve the operability of toner replenishment by using a detachable toner cartridge system which has been conventionally used. In this case, since the shape of the toner cartridge does not depend on the developing means 10, the operability of toner replenishment can be improved, and standardization with other models can be easily performed, resulting in further increase in productivity. It is possible to reduce costs due to improvement and significant economic effect.

Further, it is effective to separate the toner replenishing unit from the developer optimizing means and dispose the toner replenishing unit at a different position to transfer only the toner to the developer optimizing means in order to increase the degree of freedom in layout. is there.

In the developing means 10 according to FIG. 2 described above, only one developing sleeve indicated by reference numeral 100 is used, whereas in the developing means 10 'of this example, as shown in FIG. The difference is that, in addition to the developing sleeve 100, another developing sleeve 100 'is provided below the developing sleeve 100. In other respects, the structure is the same as that of the developing unit 10, and thus members having the same functions are designated by the same reference numerals and description thereof will be omitted.

Also in the developing device 10 'of this embodiment, the developer optimization unit 500 is used in accordance with the example of the developing device 10 described above.
Are connected to form a developing device.

The developer supplying member 110 supplies the developer directly to the developing sleeve 100, which is the developing sleeve that first develops the electrostatic latent image among the plurality of developing sleeves. It is provided so as to face the sleeve 100. Therefore, the developer is supplied to the developing sleeve 100 ′ through the developing sleeve 100.

As described above, the so-called multi-stage developing method, in which two or more developing sleeves are provided, enables high-speed developing processing, and the solid portion of the image can be uniformly developed, which is high. It is known to obtain image quality. But,
There is a problem that the circulation path of the developer inside the developing means becomes complicated and the apparatus becomes large. In this respect, according to the developing device of the present example, it is possible to maintain the developing quality at a higher level and to greatly simplify and downsize the device.

The developing device described above can also be applied to the rotary developing unit 11 as shown in FIG. The rotary developing unit 11 is used in a color image forming apparatus.

As shown in FIG. 6, this developing means is basically arranged in a cylindrical case 300 provided to face a predetermined developing position of the photosensitive drum 1 and is basically the same as the developing means 10 shown in FIG. The developing means 20, 21, 22, and 23 having the same structure are provided by being supported by a rotary support 301 which is integrally formed with the case of each developing means.

The developing means 20 is yellow toner, the developing means 21 is cyan toner, the developing means 22 is magenta toner,
The developing means 23 develops with a developer containing black toner. The developing sleeves 100Y, M of each developing means,
C and BK are provided radially with respect to the rotation center axis O of the rotation support 301, and are sequentially controlled by controlling the rotation position.
The electrostatic latent image is visualized by the color toner, which is located opposite to the photosensitive drum 1.

For each of the developing means 20 to 23 included in the rotary developing unit 11, the developer optimizing unit 500 already described is provided.

A plurality of these developer optimizing units 500 are fixedly arranged on the immovable member at a position different from the position where the rotary type developing unit is provided, corresponding to each developing means, and a plurality of developer transfer / circulation. It is connected to the developing means through means. Each developer transfer / circulation means is a supply path connecting the inlet of each developing means and the developer optimizing means according to the inlet 111a of the developing means 10, and an outlet and a developer optimizing means according to the outlet 121a. A discharge passage connecting the above and a developing means, a developer optimizing means, a supply passage, a developer transfer pump provided in a developer circulation passage constituted by a discharge passage, and a foreign matter removing means.

Therefore, the developer passing through the supply path is a developer whose agent concentration and charge amount have been optimized, and the developer passing through the discharge path is a developer before being optimized.
As described above, each developing means accommodates each one of yellow, magenta, cyan, and black developers.

In this example, since four developing means are provided, four developer optimizing units are provided correspondingly. The foreign matter removing means is achieved by a filter, electrostatic adsorption, centrifugation or the like according to the above-mentioned example. Since the supply pipe and the discharge pipe are connected between the developing means and the developer optimizing means in accordance with the configuration shown in FIG. 2, there are a total of eight tubes.

In color development, when the rotary developing unit is continuously rotated in only one direction in order to sequentially face each developing sleeve to the photosensitive drum, the pipe connecting each developing means and the developer optimizing means is twisted. Therefore, flexible tubes are used as these tubes, and control is performed so as to repeat normal rotation and reverse rotation within a range of a rotation amount of less than one rotation.

In this embodiment, the developer optimization unit is provided separately from the developing means, so that the structure of the developing means is simplified. A member corresponding to the case 150 is a rotary support 301.
It can be manufactured integrally with. Such integration facilitates manufacture of the rotary developing unit.

As described above, in the case where the rotary developing unit is provided with the developer optimizing unit, there is an advantage in the monochromatic developing means for black and white shown in FIGS. 2 and 6, that is, the rotary developing unit portion. The advantages of miniaturization, simplification, cost reduction, high reliability, low power consumption, easy maintenance, etc. can be obtained to a greater extent.

[0077]

According to the present invention, the developing means constituted so as to face the electrostatic latent image carrier is downsized, and the structure is simplified.
A developing device with improved operability during maintenance can be provided.

[Brief description of drawings]

FIG. 1 is a block diagram illustrating a configuration of a developing device.

FIG. 2 is a diagram illustrating a configuration of a developing device together with a cross section of a developing unit.

FIG. 3 is a diagram illustrating a configuration of a developing device together with a perspective view of a developing unit.

FIG. 4 is a sectional view of one side of a developing unit.

FIG. 5 is a diagram illustrating a cross section of a developer optimizing unit and a developer transfer pump.

FIG. 6 is a cross-sectional view illustrating another example of developing means.

FIG. 7 is a sectional view illustrating still another example of the developing unit.

[Explanation of symbols]

 10 developing means 100 developing sleeve 110 developer supplying member 111a inlet 120 developer collecting member 121a outlet 130 developer layer regulating member 150 case 170 stirring member 500 developer optimizing unit 200 developer transferring / circulating means 1000 developer optimizing means

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location G03G 15/09 Z

Claims (7)

[Claims] 1. An electrostatic latent image bearing member is disposed so as to face the electrostatic latent image bearing member, and rotates in the same direction at a portion facing the electrostatic latent image bearing member.
In a developing device including a developing means having a developing sleeve for applying a developer, which is a mixture of toner and carrier, to the electrostatic latent image carrier, and developing the electrostatic latent image on the electrostatic latent image carrier, A developer optimization unit that is configured as a unit separate from the developing unit, is disposed at a position different from that of the developing unit, and optimizes the concentration and charge amount of the developer, and the development optimized for the developing unit. A developer optimization unit comprising a developer transfer / circulation unit that transfers the developer and transfers the remaining excess developer applied to the development from the development unit to the developer optimization unit; The developing means includes a developer supplying member for supplying a developer to the developing sleeve, a developer layer regulating member arranged between the developer supplying member and a developing position, and the developer layer regulating member. I was scraped off by A developer recovery member for recovering a part of the surplus developer, and the remaining developer recovered by the developer recovery member,
An agitating member that agitates the developer from the developer optimizing means and the remaining developer provided to the electrostatic latent image bearing member by the developing sleeve, and transfers the developer to the developing sleeve; A developing device comprising: an inlet for accepting the developer optimized by the optimization means; and an outlet for sending the developer recovered by the developer recovery member to the developer optimization means. 2. The developing device according to claim 1, wherein the developer supply member is provided between the developer layer regulating member and the stirring member. 3. The developing device according to claim 1, wherein a plurality of the developing sleeves are provided. 4. The developing device according to claim 1, wherein a plurality of the developing sleeves are provided, and the developer supplying member supplies the developer only to one of the developing sleeves. 5. The developing device according to claim 3, wherein the developing sleeve is two and the developer supplying member is one, and the developer supplying member is an electrostatic latent image of the developing sleeve. A developing device that supplies a developer to a developing sleeve that first develops. 6. The developing device according to claim 1, wherein a plurality of developing means are provided radially with respect to a central axis of rotation, and the developing sleeve of each of these developing means and the latent image carrier are controlled by controlling the rotational position. And a developing device that is configured as a part of a rotary developing unit that sequentially develops by facing each other. 7. The developing device according to claim 6, wherein each of the developing means accommodates each of yellow, magenta, cyan, and black developers for each color.