JP3505110B2 - Developing device - Google Patents

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 which an electrostatic latent image formed on an image carrier is visualized with a toner as a colorant.

[0002]

2. Description of the Related Art In an image forming apparatus employing an electrophotographic system such as a copying machine or a printer, an electrostatic latent image is formed on the surface of a photoconductor which is an image carrier, and the latent image is visualized. Further, there is provided a developing device configured to supply a developing agent such as a toner, which is a colorant, to the photoconductor side to attach the toner.

The developing device develops the electrostatic latent image formed on the photoconductor, and the developed toner image is transferred to a sheet or the like as a transfer material. And after transfer,
A part of the toner that could not be transferred remains on the surface of the photoconductor. The remaining unnecessary toner is removed from the surface of the photoconductor in order to repeat the next image formation. Therefore, a cleaning device for removing the toner remaining on the surface of the photoconductor after the transfer is provided, and the unnecessary toner removed by the cleaning device is accommodated in the accommodating portion in the cleaning device.

Therefore, as a developing device, for example, FIG.
As shown in FIG. 3, a developing roller 34 that conveys a developer composed of toner and a magnetic carrier to a developing area corresponding to the photoconductor 2 by using magnetic force is provided, and the developer is collected in the developing tank after the development. I am trying. Therefore, in order to stabilize the development, the collected developer is once separated from the developing roller 34 and a new developer is supplied to the developing roller 34. This stabilizes the development,
I always try to get a good visual image.

In order to separate the developer collected from the developing roller 34 after development, the magnetic poles of the magnet 34b provided in the non-magnetic cylindrical sou rib 34a constituting the developing roller 34 are odd poles. . In the area where the developer after development is separated, the adjacent magnetic poles have the same polarity. As a result, the developer is naturally separated from the developing roller 34.

In the developing device having the above-described structure, the developing roller 34 is opposed to the photoconductor 2 which is an image carrier,
The electrostatic latent image formed on the photoconductor 2 is visualized. In this case, in order to perform good development, the developer is attached to the developing roller 34 in a uniform state, and the toner amount contained in the developer is constant (concentration of toner is constant) and sufficiently stirred. Are required.

Therefore, the developer is stored in the developing roller 3
A supply stirring roller 35 that stirs and supplies the developer is provided in a developing tank 30 that rotatably supports 4. Then, by performing the development, only the toner in the developer is consumed, so that the amount of toner in the developer, that is, the toner concentration decreases, so that the toner is replenished in the developing tank. At this time, the replenished toner remains as it is in the developing roller 3.
When the toner is fed to No. 4, the toner may be developed without being sufficiently agitated, resulting in defective development. In addition, the toner is partially replenished, so that the toner is not evenly distributed in the developing tank, and a partial density difference is generated, which results in defective development, that is, defective image quality.

Therefore, it is necessary to sufficiently stir the replenished toner in the developing tank 30 to make the distribution state uniform, and then to supply the developer from the supply stirring roller 35 to the developing roller 34.

[0009]

Therefore, the applicant of the present invention has proposed a developing device for sufficiently agitating the toner to be replenished and the toner to be replenished and supplying the toner to the developing roller.
No. 60367 “Developing device”.

As shown in FIG. 11, a developing roller 34 is rotatably provided in a developing tank 30 for storing a developer, and a supply stirring roller 35 for supplying the developing agent to the developing roller 34 is arranged oppositely. There is. A first and a second stirring roller are provided in an upper stirring chamber 33 provided so as to divide the entire developing tank 30 into upper and lower parts by a partitioning section 31. The lower part of the developing tank 30 divided into two parts is the developing chamber 3
2, the developing chamber 32 is provided with a developing roller 34 and a supply stirring roller 35, and the developing roller 34 is magnetically attracted to the developing roller 34 and is being conveyed to the developing area of the photoconductor 2 facing the developing roller 34. Then, the toner passes through the regulation blade 38 that regulates the amount of the developer to a constant level.

Except for the developer passing through the regulation blade 38, the regulation blade 38 is separated from the developing roller 34.
And the upper stirring chamber 3 through an opening (intake port) 40 that is formed at a distance from the tip of the partition 31 that constitutes the upper stirring chamber.
It is sent to 3. The developer is formed on one wall surface (front side in the figure) by the first and second stirring rollers 36 and 37.
From the other wall surface (back side) and from the other wall surface to the one wall surface while being agitated. The toner is replenished on the way, and the replenished toner is sufficiently agitated on the way of being circulated and conveyed so that the toner distribution becomes uniform.

On the side of the second stirring roller 37 of the stirring chamber 33, there is provided a return port 43 for sending back to the supply stirring roller 35 on the lower side of the developing chamber 32. for that reason,
The sufficiently agitated developer is returned to the developing chamber 32, and the developer is agitated via the supply agitating roller 35 and supplied to the developing roller 34.

With such a structure, the developer is circulated and conveyed between the lower developing chamber 32 and the upper stirring chamber 33, and the replenishment toner can be sufficiently mixed into the developer and stirred, and the developer is transferred to the developing roller 34. Can be sent. That is, the replenished toner is immediately sent to the developing roller 34, and good development can be maintained without causing defective development.

However, the inventors of the present invention found out the following problems. That is, when the developer is circulated and conveyed, that is, when the developing roller, the stirring roller, and the first and second stirring rollers 36 and 37 are continuously driven, the circulation is performed. . But,
The developer is sent from the upper stirring chamber 33 side to the developing chamber 32 side through the return port 43 and is returned in a state of being naturally dropped.

On the other hand, the excess developer regulated by the regulation blade 38 is introduced into the upper stirring chamber 33 through the inlet 40.
It is supplied so as to be pushed inward. for that reason,
The amount of developer returned from the side of the upper stirring chamber 33 tends to increase. As a result, the amount of developer on the lower developing chamber 33 side increases.

In this case, when the developing operation by the developing device is completed, the other stirring rollers 35, 36, 37, including the developing roller 34, are naturally stopped from rotating. In this state, the developer on the developing chamber 32 side becomes excessive, and the developer on the stirring chamber 33 side runs short. Then, at the next development, the supply stirring roller 3 including the developing roller 34 etc.
5 is rotated, the supply stirring roller 3 on the developing chamber 32 side is rotated.
The rotational torque of 5 and the like may increase, resulting in poor rotation. Also, since the amount of developer is small on the stirring chamber 33 side,
Sufficient developer agitation cannot be initially desired.

As a result, in order to start the development, the development roller 34, the supply stirring roller 35, etc. should be rotated sufficiently to perform the development after the flow of the developer is formed. The start of development will be extremely delayed.

It is also conceivable that the increase in the driving torque due to the start of rotation may cause an adverse effect due to the heat generation of the developing roller 34 and the supply stirring roller 35, that is, cause the toner to be fused and the developing characteristics to change to cause defective development. Therefore, a driving motor or the like of the developing device may have a large driving torque, but the tendency that the initial development start time is delayed cannot be eliminated.

Further, when the developer is agitated, it is obvious that if the agitation time is prolonged, the developer is deteriorated. Therefore, in the initial stage of development, creating a sufficient developer flow results in a longer stirring time, resulting in accelerated deterioration of the developer. Therefore, it is required to shorten the stirring time of the developer as much as possible.

Further, it is necessary to take a sufficient stirring time, and at the same time, when the toner is replenished, the reinforced toner is mixed with the developer while being conveyed on the side of the stirring chamber 33 and is stirred to be conveyed. The distribution is uniform in the direction, but the time tends to be long. That is, the stirring chamber 3
This is also due to the small amount of developer on the 3 side. Further, when the circulation of the developer is balanced between the developing chamber 32 side and the stirring chamber 33, the flow of the developer is improved, and the time until uniform distribution is considered to be shortened. As described above, due to the tendency that the amount of the developer on the developing chamber 33 side increases, the time until uniform distribution becomes long.

In view of the above-mentioned problems, the present invention makes it possible to sufficiently stir the developer, particularly to evenly distribute the toner to allow sufficient stirring, and to perform good development without prolonging the stirring time. The purpose is to provide a device.

Another object of the present invention is to divide a developing tank constituting a developing device into upper and lower parts so that the developer is circulated between a developing chamber and a stirring chamber, and the developer is circulated and conveyed. The purpose is to sufficiently stir during the process to prevent the developer from becoming excessive in the developing chamber side, and to eliminate sufficient stirring and wasteful stirring.

[0023]

A developing device according to a first aspect of the present invention for attaining the above-mentioned object develops a developer carrying member carrying a developer containing toner and carrying it to the image carrying member side. The developer tank is provided in the tank, and the developer tank is provided in the lower area divided into two by dividing the developer tank into upper and lower parts to form a developing chamber, and the upper area is provided with a conveying means for agitating and conveying the developer. The partition section tip and the regulating means are provided as a chamber so that the developer regulated by the regulating means for regulating the amount of the transported developer carried on the developer carrying body is fed to the stirring chamber side. Between the developing chamber and the agitating chamber, a return port for returning the developer to the developing chamber side is provided in the partition portion on the agitating chamber side, and a gap between the developing chamber and the agitating chamber is provided. In the developing device configured to circulate in An agitating member for agitating the developer on the developing chamber side corresponding to the write-back port and supplying the developer to the developer carrying member side is provided, and one end is provided on the partition section on the developing chamber side and the other end is provided. Is provided with a restriction member facing the stirring member to restrict the flow of the developer.

According to such a configuration, the developer is regulated by the regulation means, and is transported to the developing position by the developer carrying member and provided for development. Then, the developer regulated by the regulation blade and removed from the developer carrying member is fed into the stirring chamber side from the intake port, stirred while being conveyed by the stirring means, and returned to the developing chamber from the return port. Next, when the returned developer is further agitated by the agitating member and supplied to the developer carrying member side, a part of the developer is regulated by the regulating member and returned to the return port side. It is supplied to the developer carrier while being mixed and stirred with the developer to be returned further. As a result, the developer is efficiently stirred.
Further, by providing the regulating member, the amount of the developer returned to the developing chamber side is regulated, and the excessive feeding of the developer to the developing chamber side is prevented.

Therefore, the stirring efficiency is improved, the time required for stirring can be shortened, the deterioration of the developer due to a long time interval can be suppressed, and the driving torque for driving the stirring member, the developer carrier, etc., can be increased. Can also be suppressed, and toner fusion and the like can be prevented.

Further, in the developing device according to the first aspect of the invention having the above-mentioned configuration, one end of the regulating member, which is provided to face the stirring means, faces the top of the stirring means , Place them in close proximity . According to this arrangement, the regulating member regulates the uppermost portion of the developer supplied to the developer carrying member side through the stirring member, in particular.
Sometimes specific gravity of the toner is light, the surface of the flow of the developer so on are toner gliding, prevents the Ru is supplied to the developer carrying member to remain there is not enough stirring action during which the return port side Then, it is surely returned and mixed into the developer flowing from the return port, and the stirring action is promoted. As a result, the well-stabilized and stable developer is supplied to the developer carrier to be used for the development, so that the good development can be maintained and the deterioration of the image quality can be suppressed.

Further, the first feature of the above-mentioned configuration
In the developing device according to the invention, one end portion of the regulating member, which is provided so as to face the stirring means, is arranged at a certain distance upstream from the top of the stirring means in the developer flowing direction. According to this structure, the developer to be returned is regulated when the stirring member attempts to convey it,
It is possible to smoothly form the flow of the developer without disturbing the fluidized state largely by the returned developer. Further, when the returned developer is about to be conveyed by the stirring member, a part of the developer is regulated and the mixing action with the developer to be returned is promoted, and it can be expected that the stirring efficiency is further improved.

In the developing device according to the first aspect of the present invention, further, one end of the regulating member is a surface inclined toward the upstream side in the developer flowing direction on the developer carrying side. By forming the developer in the state, the developer passing through the regulating member is guided to the developer carrying body side along the inclined surface, so that the effect of suppressing the obstruction of the flow path of the developer occurs. Further, the disturbance of the flow of the developer can be suppressed and the stirring efficiency can be further promoted.

Further, in the developing device according to the first aspect of the present invention having the above-mentioned structure, the one end portion of the regulating member, which is provided so as to face the stirring means, has a distance of 1.5 mm or less from the stirring means. By setting to 3, the effect of regulating the developer is enhanced and the effect of promoting the stirring of the developer is enhanced. Therefore, the sufficiently stirred developer can be supplied to the developer carrying member, and good development can be achieved.

[0030]

[0031]

[0032]

[0033]

[0034]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below in detail with reference to the drawings. A first embodiment of the developing device of the present invention will be described with reference to the drawings shown in FIGS.

First, before the developing device according to the first embodiment of the present invention will be described in detail with reference to FIG. 1 and the like, a schematic structure of an image forming apparatus including this developing device will be described with reference to FIG. Briefly explained.

A photoconductor 2 which serves as an image carrier formed in a drum shape and rotated during image forming operation is provided at substantially the center of the main body of the image forming apparatus 1. Various process means for forming a toner image are arranged so as to face the periphery of the photoconductor 2.

The above-mentioned various process means are such that the charger 3 for uniformly charging the surface of the photosensitive member, the optical system (image exposing device) 4 for irradiating an image with light according to the image, and the optical system 4 are used for exposure. The developing device 5 according to the present invention for visualizing the electrostatic latent image formed on the surface of the photoconductor 2 by means of a sheet-like paper or intermediate transfer to which the developed image (toner image) is appropriately conveyed. A transfer device 6 for transferring to the body, a peeling member (static elimination member) 7 for peeling the transferred sheet from the photoconductor, a cleaning device 8 for removing residual developer (toner) not transferred to the photoconductor surface after the transfer, and A static eliminator 9 that removes the charged charges remaining on the surface of the photoconductor is arranged in this order in the rotational direction of the photoconductor.

In this case, in the image forming apparatus for forming a color image, the one using the tie denm system is provided with various process means for forming a toner image on the periphery of the above-mentioned photoreceptor, and the toner of the color to be used is used. Different developing devices 5 are arranged to face each other. The other process means are the same. Then, the toner images formed by the respective colors are once transferred, for example, on the intermediate transfer body, and then transferred at one time on one sheet. Alternatively,
The sheet is adsorbed on the conveyor belt and passed through the transfer positions facing the respective photoconductors, whereby the toner images of four colors are sequentially superposed and transferred.

In the apparatus of FIG. 6, a large amount of the above-mentioned sheets are accommodated in a tray or cassette 10,
One sheet of the accommodated sheet is fed by the feeding unit 11,
It is sent to the transfer position described above. The sheet after the transfer is separated from the photoconductor 2 and sent to the fixing device 12.

The fixing device 12 fixes the unfixed toner image transferred onto the sheet as a permanent image, and the surface facing the toner image is heated to a temperature for melting and fixing the toner. A heat roller is provided, and a pressure roller that pressurizes the heat roller to bring the paper into close contact with the heat roller is provided. A toner image is formed on the surface of the sheet that has passed through the fixing device 12, and the sheet is discharged to the outside of the image forming apparatus through a discharge roller (not shown).

In addition to the sheet feeding from the cassette 10 described above, the sheet is provided with a sheet feeding unit equipped with a sheet feeding cassette that can be attached to the lower part of the main body of the image forming apparatus 1 if necessary. The sheet is sent from the paper feeding unit to the transfer position via the transport path. Further, a manual paper feeding unit is provided to appropriately feed a sheet of any size.

On the other hand, the optical system 4 for exposing the surface of the photoconductor 2 is placed on a document table 13 made of, for example, transparent glass as shown in the figure, and an illuminating device 14 including a lamp for illuminating the document and the document. For guiding the reflected light from the first mirror 15 to a lens for forming an image on the photoconductor 2, and a first scanning means having a first mirror 15 for reflecting the reflected light from the first mirror 15 to a required position. Second scanning means supporting the second and third mirrors 16 and 17, the image forming lens 18, and the lens 18
A pair of fixed mirrors 19 and 20 for adjusting the optical path length and the like for guiding the reflected light passing through the photoconductor 2 to the photoconductor 2, and a fixed mirror 21 for finally irradiating the photoconductor 2 with the reflected light. ing.

Although the optical system 4 is based on an analog copying machine, in a digital copying machine, reflected light from an original is imaged on an image reading element, particularly a reading element such as a CCD for photoelectrically converting. . This formed image is CC
It is output from D as an electric signal according to the image density, and A /
D-converted and output as digital image data. Such image data is sent to an optical writing unit such as a laser (not shown), and an electrostatic latent image is formed by irradiating the surface of the photoconductor 2 with an optical image corresponding to the image data. In such a digital copying machine, image data can be similarly formed by irradiating the photoconductor 2 with the image data sent from the other image input means by the optical writing means.

Next, embodiments of the developing device of the present invention will be described in detail with reference to the drawings.

(First Embodiment of the Present Invention) The developing device 5 in the present invention uses a colorant to visualize the electrostatic latent image formed on the surface of the photoreceptor 2 as shown in FIG. It contains a developer containing a toner. The developing device 5 will be described below with reference to FIG. 1.
A developing tank 30 having a container structure for containing a developer is provided, a partition portion 31 is provided to divide the developing tank 30 into upper and lower parts, and the developing tank 30 is divided into a developing chamber 32 and a stirring chamber 33.

On the side of the developing chamber 32, there are provided a developing roller 34 which holds a developer and is rotatable, and a supply stirring roller 35 which constitutes a stirring means for supplying or / and stirring the developer. Above the developing chamber 32, especially the developing roller 34
First and second agitating rollers 36 and 37, which constitute a conveying means having a screw structure for supplying toner and circulating and conveying the developer, are arranged side by side on the agitating chamber 33 side above the agitating roller 35.

The developing roller 34 comprises a cylindrical non-magnetic sleeve 34a and a mabnet roller 34b provided in the sleeve 34a and having an odd number of magnetic poles of 5 magnetic poles. The magnetic pole N1 of the mabnet roller 34b is a developing pole, and is fixed so that the magnetic pole N1 is arranged at a developing position facing the photoconductor 2. Then, the sleeve 34a provided so as to cover the outer periphery thereof is rotated in the arrow direction, the developer is adsorbed on the surface by the magnetic force of the mabnet roller 34b and conveyed, and the developer after development is transferred to the developing chamber 32 of the developing tank 30. I am trying to collect it.

The above-mentioned developer may be, for example, a two-component system composed of a toner and a magnetic carrier, or a one-component system in which the toner itself has magnetism. Therefore, the developer is non-magnetic sleeve 34a due to the magnetic force of magnet roll 34b.
Adsorbed on the surface. A part of the adsorbed developer is removed by a regulating blade (doctor) 38 so that the adsorbed amount becomes constant before being conveyed to a developing position facing the photoconductor. That is, the regulation blade 38 has one end fixed to the frame 39 attached to the developing tank 30 or the like, and the other end arranged with a certain gap (spacing) from the sleeve 34a. Therefore, the amount of the developer that slips through the regulation blade 38 is regulated to a constant amount adsorbed to the sleeve 34a.

The supply stirring roller 35 has a structure in which, as shown in FIG. 3, for example, an elliptical stirring blade (blade) 35a is tilted at a predetermined angle on a rotating shaft 35b at equal intervals. Further, the supply stirring roller 35 having a structure having spiral (screw) -shaped blades such as a toner conveying roller may be used instead of such a configuration.

Further, as shown in FIG. 3, the supply stirring roller 35 is constituted by fixing a large number of elliptical blades (collars) 35a to a shaft 35b at a predetermined inclination angle. As shown in FIG. 3, the blade 35a is partially formed with a notch 35c serving as a passage portion that allows the developer to be conveyed in the axial direction. A supply piece 35d fixed to the shaft 35b is provided between the blades 35a. As a result, the developer can be sent to the developing roller 34 side and the collected developer can be sent to the side opposite to the developing roller 34, and stirring can be performed.

The supply stirring roller 35 is driven to rotate in the direction of the arrow in FIG. 1, and has an elliptical blade 35a.
At, the developer is conveyed in the axial direction and stirred. Further, the developer is conveyed and agitated by the supply piece 35d in a direction orthogonal to the axis 35b direction. In this way, the developing tank 3 stirred and conveyed by the supply stirring roller 35
The developer in the developing chamber 32 of 0 is supplied to the developing roller 34. In this case, on the developing roller 34 side, the developer is drawn up by the magnetic pole S3 of the mabnet roller 334b.

The developer is adsorbed on the surface of the sleeve 34a of the developing roller 34 which is rotated as described above, and the excess material is removed by the restricting member 38 arranged so as to face the magnetic pole N2 of the mabnet roller 34b. . Then, a predetermined amount of the developer is attracted to the sleeve 34a and reaches the position of the developing magnetic pole N1 through the magnetic pole S1. At this position, the developer stands like a brush and is rubbed against the surface of the photoconductor facing the brush. As a result, toner adheres according to the electrostatic latent image formed on the surface of the photoconductor 2 and is developed as a toner image.

The developer after being contributed to the development is rotated by the sleeve 34a, so that the magnetic pole S of the mabnet roller 34b is generated.
It is collected in the developing tank 2 in cooperation with 2. And
In the magnetic force relationship between the magnetic poles S2 and S3 of the mabnet roller 34b, the developer is separated from the sleeve 34a, and is fed to the opposite side of the developing roller 34 side by the feeding piece 35d of the feeding stirring roller 35 as shown in FIG. After being taken in and sufficiently stirred for the next development, it is supplied to the developing roller 34 as described above. The developer thus contributed to the development is recovered from the development position, circulated and supplied, and contributed again to the development.

Therefore, in the present invention, the sleeve 34 of the developer is conveyed while the developer is being conveyed to the developing position.
The developer removed by the regulation blade 38 that regulates the amount of adhesion to a is configured to be sent to the above-mentioned stirring chamber 33 at the upper portion. The structure for that is the developing tank 3.
A space is provided between the tip of the partition 31 that divides 0 into upper and lower parts and the regulation blade 38 to form an intake port 40.

The partition portion 31 has its tip end portion facing along the developing roller 34, and is provided to guide the developer adhering to the developing roller 34 to the regulating blade 38 side. Then, the tip of the partition portion 31 forms an intake port 40 at a constant distance from the regulating member 38. Therefore, the excess developer regulated by the regulation member 38 is efficiently sent to the stirring chamber 33 side above the intake port 40 along the rotation direction of the developing roller 34.

On the other hand, the agitating chamber 33 is formed in the upper space area divided by the partition portion 31, and is provided with the first and second agitating rollers 36 and 37 as described above. The first and second stirring rollers 36, 37 are
As shown in FIG. 2, the developing tank 30 is rotatably supported on both side walls via bearings 29.

The first stirring roller 36 has an intake port 40.
The screw shape (spiral shape) is provided on the side opposite to that of FIG. 2 so that the toner supplied from the developer and toner supply port 28 in FIG. Blades are formed. The second stirring roller 36 and the second
As shown in FIG. 2, the stirring roller 37 of FIG.
It is the reverse of 6. Therefore, the carrying direction of the developer and the toner is opposite to the carrying direction of the first stirring roller 36.

A toner replenishing device 27 is detachably attached to the developing device 5 at the toner replenishing port 28 as shown in FIG. The toner supply device 27 is provided with a corresponding supply port communicating with the toner supply port 28, and the supply port is provided with a supply unit. Therefore, when necessary, toner is replenished from the toner replenishing device 27 via the toner replenishing port 28 to one end portion of the stirring chamber 33 on the side of the first stirring roller 36.

Further, between the first and second agitating rollers 36 and 37 provided in the agitating chamber 33, the developer conveying direction is set so that the developer and the like are not conveyed to the other side. A baffle plate 41 that blocks (shields) the conveyance in the orthogonal direction is provided. The baffle plate 41 is integrally molded with the partition part 31, and has passage ports 42 provided at both ends and near the center. The passage ports 42a and 42b at the ends are openings for feeding the developer conveyed by the first and second agitating rollers 36 and 37 to the other side along the arrow direction, and are located near the center. The passage port 42c is designed to send a part of the developer from the first stirring roller 36 side to the second stirring roller 37 side. Therefore, the passage port 42 of the second stirring roller 37
A part of a screw blade (blade) for conveying the developer is lacking in a portion facing c.

As described above, the first and second stirring chambers 33
The developer is agitated while being conveyed in the rotation axis direction by the agitating rollers 36 and 37, but the developer is agitated while being conveyed by the second agitating roller 37 on the side of the lower developing chamber 32. It falls to the 35 side and is returned. Therefore, a return port 43 (see FIG. 1) is formed in the lower part of the partitioning part 31 which divides the developing tank 30 into two parts, which is opposed to the first stirring roller 6. Similar to the intake port 9, the return port 43 is formed in the partition portion 31 over the entire area in the rotation axis direction.

Therefore, on the side of the stirring chamber 33, the developer sent through the above-mentioned inlet 40 is conveyed in the axial direction by the first stirring roller 36, and then transferred to the second stirring roller 37. Then, it is conveyed in the opposite direction by the second stirring roller 37, and is gradually fed back to the supply stirring roller 35 on the developing chamber 32 side in the middle thereof. In this way, the developer is circulated and conveyed in the developing tank 30.

A toner concentration sensor 44 for detecting the toner concentration of the developer is provided on the bottom surface of the developing tank 30 facing the supply roller 4. The toner concentration sensor 44
Is a magnetic permeability sensor, for example, and when the amount of toner in the developer decreases, the magnetic permeability increases, so that the output increases, and a toner shortage is detected.

At this time, if the toner concentration of the developer is lowered, the toner concentration sensor 44 detects the state. In response to this detection, the toner is replenished from the toner replenishing device 27 side through the replenishing port 28.

Further, according to the present invention, in the developing device having the above-described structure, the flow of the developer is regulated particularly toward the developing chamber 32 side, and in order to efficiently stir the developer, FIG.
A regulating member 45 is provided as shown in FIG. The regulating member 45 has one end fixed to the surface of the partition portion 31 on the developing chamber 32 side, that is, the lower surface, and is provided such that the free end side faces the supply stirring roller 35. The regulating member 45 is provided so as to hang down from the partitioning portion 31, is located close to the stirring blade 35a of the supply stirring roller 35, regulates a part of the developer that is stirred and conveyed, and efficiently stirs the developer. ing.

The regulating member 45 is an elongated plate-like member that covers the entire area of the supply stirring roller 35, is a non-magnetic material, and is made of an elastic material. For example, as the material, polyethylene terephthalate (PET), aluminum, copper or the like can be used. Further, when the developing tank 30 is molded with resin, it can be integrally molded with the resin of this developing tank.

By providing the regulating member 45 in this way,
The developer returned from the agitating chamber 33 side through the return port 43 is partially regulated when being supplied to the developing roller 34 side by the supply agitating roller 35, and has a spiral movement as shown in FIG. Therefore, the stirring efficiency can be increased. Also,
The developer supplied to the developing roller 34 is the developing roller 3
4, the contact with the developer adhering to No. 4 is promoted, and the swirling motion as shown in FIG. 1 improves the stirring efficiency, while the replacement or exchange with the developer collected by the developing roller 34 is promoted. It

Further, by providing the regulating member 45, the amount of the developer returned from the return port 43 is regulated, and the developing chamber 3
It is possible to prevent the amount of the developer on the second side from becoming excessive. For example, the developing device 5 is stopped, the supply stirring roller 35 including the developing roller 34, and the first and second stirring rollers 36, 3
Seven rotation is stopped, the spatial region of the developing chamber 32 is regulated by the regulating member 45, it such ku above the space area of the developer flows through the return port 43, the excess developer There is no such thing. As a result, it is possible to suppress the tendency that the developer is biased toward the developing chamber 32 side and the drive torque due to the rotation by the supply stirring roller 35 and the developing roller 34 side increases.

Therefore, the developer is agitated by rotating the developing roller 34, the supply agitating roller 35, etc. by the image forming operation of the developing device 5, and the rising time is not prolonged and the first copy time is extended. Can be prevented. Moreover, it is possible to prevent problems such as toner fusion due to heating due to an increase in driving torque.

Next, in order to further understand the present invention,
The flow of the developer in the developing tank 30 of the developing device 5 will be described with reference to FIGS. 4 and 5. Each arrow in FIG. 4 indicates the direction in which the developer flows.

First, in FIG. 4A, when the toner is replenished to one end P (marked with ●), the upper stirring chamber 3
The developer is stirred by the first stirring roller 36 on the third side while being conveyed in the rotation axis direction thereof. At this time, on the side of the lower developing chamber 32, the excess developer regulated by the regulating blade 38 is removed by the upper stirring chamber 33 as shown by an arrow 22a in FIG.
Sent to. As shown in FIG. 4A, the developer 22a is fed from the intake port 40 over the entire area of the stirring roller 36 in the axial direction, mixed with the supplied toner, stirred, and conveyed to the rear (R) side. The developer sent to one end, that is, the rear (R) side is
In (a), it is sent from the first stirring roller 36 to the second stirring roller 37 side through the passage port 42b of the baffle plate 41,
While being conveyed to the front end (F), which is the other end, by the second agitation roller 37, the replenishment toner is mixed with the developer and agitated.

The developer conveyed by the second agitating roller 37 is gradually transferred from the return port 43 to the lower developing chamber 32 during the conveyance, as the developer 22b in FIG. It is returned as indicated by reference numeral 22b. When the toner is replenished, the returned developer 22b is sufficiently mixed and agitated with the replenishment toner, further agitated by the supply agitation roller 35 on the developing chamber 32 side, and supplied to the developing roller 34. .

When the developer carried by the second stirring roller 37 is carried to the front (F) side end of the stirring chamber 33 without returning from the return port 43 to the developing chamber 32, It is sent to the first agitating roller 36 side from the passage port 42a of the partition plate 41, and is conveyed to the end portion side of the rear (R) together with the developer 22a sent from the intake port 40.
Such conveyance is repeated, and the developing chamber 32 is returned from the return port 43.
The circulation conveyance is repeatedly performed to the side and from the intake port 40 to the stirring chamber 33.

Then, on the developing chamber 32 side, the developer 22 returned from the return port 43 as described with reference to FIG.
4b is conveyed from the rear (R) side to the front (F) side by the supply stirring roller 35 as the developer 22c shown in FIG. 4B, while part of the developer 22c is moved to the developing roller 34 side as the developer 22d. Supply. On the side of the developing roller 34, the developer after development is stored in the developing chamber 32 as shown in FIG.
It is collected as 2e. The collected developer is shown in FIG.
Is indicated by reference numeral 22e in FIG.
Of the developer 22 which has been taken into the wall surface side of the developing tank 30 in FIG.
It is agitated with c and sent as the developer 22d supplied to the developing roller 34 side as described above.

The developer agitated and conveyed by the supply agitating roller 35 passes between the tip of the regulating member 45 and becomes the developer 22d, which is supplied to the developing roller 34. Therefore, a part of the developer regulated by the regulation member 45 is regulated and sent back to the return port 43 side (rear side) so as to form a spiral flow as shown by the arrow in FIG. ,
Further, the mixing and stirring of the developer are efficiently performed.

On the other hand, the developer 22d supplied to the developing roller 34 side is magnetically attracted to the surface of the sleeve 34a of the developing roller 34 and is conveyed. The amount of adhesion by the regulating blade 38 on the sleeve surface is restricted, it is regulated to a constant amount of the developer 22f through the regulating blade 38. The regulated amount of the developer 22f, which has passed through the regulation blade 38 and is regulated, is sent to a developing region facing the photoconductor 2 and is used for development.

After the development, the developer 22f becomes the developer 22e which is collected in the developing chamber 32 by the rotation of the developing roller 34 as described above, and is stirred by the supply stirring roller 35. This stirring is as described above.

On the other hand, in FIG. 4B, the developer 22g regulated and removed from the developing roller 34 by the regulating blade 38 is partially returned to the regulating member 45 side (the side facing the developing roller). The toner is mixed with the developer conveyed from the supply agitating roller 35, agitated and mixed in a spiral shape as shown in FIG. 1, and is again sent to the developing roller 34. Thus, good agitation is promoted in this part.

Then, the remaining developer 22g regulated by the regulating blade 38 is fed into the upper stirring chamber 33 as the developer 22a through the intake port 40 as shown in FIG. 4 (a). The circulation and transportation of the developer described above are repeated, and the developer 22 is efficiently and favorably stirred. In addition, as described above, the replenishment toner is mixed and stirred while being conveyed in one direction on the stirring chamber 33 side via the first and second stirring rollers 36 and 37, and the developing roller 34 as it is.
It is not directly conveyed to, but is subjected to development after being well stirred and mixed, and development failure does not occur.

As described above, the tip end portion of the regulating member 45 provided above the supply stirring roller 35 on the developing chamber 32 side,
The amount of the developer conveyed to the developing roller 34 is suppressed by the gap between the tip of the supply stirring roller 35 (the tip of the collar 35a of the stirring blade). Therefore, the amount of developer supplied to the developing roller 34 side is suppressed, the amount of developer returned from the stirring chamber 33 side is regulated, and a constant amount of developer can be maintained on the developing chamber 32 side. Therefore, even if the rotations of the developing roller 34, the supply stirring roller 35, etc. are stopped, the developer is not returned to the developing chamber 32 side by spontaneous fall, and a constant amount of developer can be maintained.

Further, even on the side of the upper stirring chamber 33, a predetermined amount of the developer can be secured, so that the stirring property of the developer and the transportability are deteriorated by the start of rotation, and the mixing with the toner,
Stirring efficiency will not drop.

Therefore, the rising time due to the start of the development of the developing device 4 does not become long, the rotation torque or the like does not increase, the developer is not unnecessarily rotated for a long time, and the toner is fused. The problem goes away.

FIG. 5 shows that the amount of the developer is stabilized by providing the regulating member 45 in the present invention. That is, by providing the regulating member 45, the supply stirring roller 35
A space 46 is formed in the developing chamber 32 above. The space 46 is formed by providing the regulating member 45. In the configuration shown in FIG. 9 in which the regulating member 45 is not provided, the space cannot be formed above the supply stirring roller 35, The amount of developer is also concentrated on the developing chamber 32 side. As a result, a lot of stress is generated, the deterioration of the developer is accelerated, the toner is fused, the driving torque is increased, and it takes time to start up by the start of the development, which causes the deterioration of the developer due to the extension of the stirring time. There is a problem that the result is further accelerated and the first copy time becomes long.

(Regarding the positional relationship between the regulating member and the supply stirring roller according to the first embodiment) As described above, the partition portion 31 that divides the developing tank 30 of the developing device 5 into upper and lower parts is provided.
By providing the regulating member 45, it is possible to prevent the developer from being concentrated and increasing on the developing chamber 32 side.

It is most effective that the regulating member 45 is provided corresponding to the supply stirring roller 35. In order to confirm the effect, it demonstrates below with reference to FIG.

In FIG. 7, the regulating members 45 are
An example in the case of being provided at each location of will be described below.

The position of (3) is a state in which the regulating member 45 is provided at a position away from the supply stirring roller 35 and approaching the developing roller 34 side.

In addition, at the point, the regulation member 45 is provided at the return port 43 through which the developer is returned from the stirring chamber 33.

Then, the point is a state in which the tip of the regulating member 45 is provided so as to face the top of the supply stirring roller 35. That is, the tip of the regulating member 45 is the position closest to the supply stirring roller 35.

Therefore, the flow of the developer when the regulating member 45 is provided at the position will be described below. When the regulating member 45 is provided at the position of, the distance (distance) between the tip of the regulating member 45 and the tip of the blade (flange) 35a of the supply stirring roller 35 that rotates is widened, and is accompanied by the tip portion of the supply stirring roller 35. The restriction effect described above on the flow of the developer is completely lost, and the stirring is not sufficiently performed. Further, the flow rate of the developer to the developing chamber 32 side increases, and a large amount of the developer accumulates in the developing chamber 32. Therefore, the stirring efficiency of the developer also deteriorates.

Therefore, it is conceivable that the tip of the regulating member 45 is further hung (projected) to the lower part to narrow the gap with the supply stirring roller 35. With such a configuration, the regulation effect of the regulation member 45 can be expected, but the supply amount of the developer to the developing roller 34 is significantly reduced. That is, the amount of the developer regulated by the regulation member 45 becomes too large, and the developer accumulates on the rear surface side (the return port 43 side) of the regulation member 45. As a result, the agitation efficiency is rather lowered, the supply amount of the developer is reduced, and defective development occurs due to insufficient developer on the developing roller 34 side.

The collected developer is not replaced with the supplied developer, and the developing roller 3 is used as it is.
4, the developer is not sufficiently stirred, and good development cannot be performed.

The case where the regulating member 45 is provided at the next position will be described. Even at this position, the distance between the tip of the regulating member 45 and the tip of the supply stirring roller 35 becomes wider. This eliminates the effect of providing the regulating member 45 and enhancing the stirring efficiency while regulating the developer as described above. Therefore, similarly, even if the tip of the regulating member 45 is drooped (projected) to the lower portion so as to be closer to the supply stirring roller 35, the regulating action of the developer is further strengthened similarly to the position of, and the developing roller 34 is moved to the developing roller 34. The supply amount of the developer is reduced. Therefore, the developer stays on the back side of the regulation member 45, the return of the developer from the stirring chamber 33 side deteriorates, and the developer on the developing chamber 32 side runs short.

As a result, even if the developer is collected in the developing chamber 32 by the developing roller 34 after the development, the replacement with the new developer is not sufficiently performed, and the collected developer is the new developer. At the same time, they are not mixed and are used for development, and sufficient development cannot be performed.

On the other hand, if the regulating member 45 is provided at a position in the vicinity of a position facing the top portion (the uppermost portion in FIG. 7) of the supply stirring roller 35, the second stirring roller of the upper stirring chamber 33 is provided. The developer returned from the return port 43 via 37 is regulated when it is stirred and supplied by the supply stirring roller 35. In particular, the upper developer on which the feeding and stirring roller 35 is conveyed and stirred is regulated by the regulation member 45, and a spiral flow as shown in FIG. 1 is formed on the back side of the regulation member 35. At this time, it effectively acts on the toner floating in the vicinity of the interface of the developer, that is, the toner is mixed inside the developer along a spiral flow and is supplied to the developing roller 34 while being stirred.

Originally, the toner has a lower specific gravity than the developer, especially the carrier. Therefore, the toner slides on the surface of the flow of the developer, and during that time, the toner is not sufficiently mixed and agitated to the developing roller 34. When supplied, it causes black streaks in the developed image.

In this respect, by providing the regulating member 45 according to the present invention at a position near the top of the supply stirring roller 35, even if the toner is slid on the surface of the developer flow, it is prevented. Is regulated by, and as shown in FIG. 1, it swirls into the developer which flows in next, so that a swirling stirring action occurs, and it passes through the supply stirring roller 35 and is supplied to the developing roller 34. The toner is supplied to the developing roller 34 in a stirring state.

Further, even if the tip end of the regulating member 45 is brought close to the supply stirring roller 35 or the developer flowing in through the return port 43, the developer is transferred from the supply stirring roller 35 to the developing roller 34. It is also very suitable for the supplied developer, as it does not hinder the flow path due to the retention of the developer or the like. By arranging the regulating member 45 in such a position, a spiral flow of the developer as shown in FIG. 1 is formed on both sides of the regulating member 45, and the mixing and stirring actions are promoted. Further, on the side of the developing roller 34, the recovered developer after development and the supplied developer are favorably exchanged,
The sufficiently stirred developer is used for the next development.

Table 1 below shows the development results when the regulating member 45 is provided at each position. As shown in Table 1, by arranging the regulating member 45 at the positions of and, the regulation effect was not sufficiently exerted, resulting in the occurrence of black streaks. However, by providing the regulating member 45 at the position of Are no longer formed.

[0099]

[Table 1] Further, when the tip end of the regulating member 45 at the positions of and is hung down to be close to the supply stirring roller 35, the image density is not sufficiently obtained due to insufficient supply of the developer to the developing roller 34, and the image quality is deteriorated. Was confirmed to occur.
However, when the regulating member 45 is provided at the position, stable image quality can be obtained.

Further, the regulating member 45 is arranged at the position of, and the development is performed by changing the distance between the tip of the regulating member 45 and the supply stirring roller 45, and the results are shown in Table 2 below. This was performed by changing the interval between the tip of the regulating member 45 and the tip of the blade (flange) 34a on which the supply stirring roller 45 is rotated within a range of 0.5 to 2.0 mm at intervals of 0.5 mm. That is, the amount of protrusion of the tip of the regulating member 45 was changed variously.

[0101]

[Table 2] As shown in Table 2, at intervals of at least 1.5
When it is not more than mm, the generation of black streaks is suppressed. More preferably, it is most preferably 1.0 mm or less. Here, when the interval is 0 mm, if the rotation of the supply stirring roller 35 is not regulated by the regulation member 45 and the drive torque or the like does not increase, there is no problem even in that state.
However, the gap should be at least 0.1 mm in anticipation of errors.
It can be set to the above level. Further, as shown in Table 2, by setting the thickness to at least 0.5 mm, the design error can be sufficiently implemented even if the design error and the like are taken into consideration, and it can be set to be less than that.

(Second Embodiment of the Invention) The developing device 5 having the above-described structure, in particular, by providing the regulating member 45, sufficiently stirs and conveys the developer without causing it to flow. be able to. Therefore, the regulation member 45
Is arranged so as to be positioned near the top of the supply stirring roller 35.

On the other hand, in the arrangement position of the regulating member 45 according to the second embodiment, the tip is located slightly upstream of the top of the supply stirring roller 35 with respect to the rotation direction of the roller 35 (return port 43 side). It is provided to do so. FIG. 8 shows an example thereof.

By disposing the regulating member 45 at the position shown in FIG. 8, it is possible to suppress the disturbance of the flow path of the developer flowing into the developing chamber 32 side from the stirring chamber 33 side through the return port 43. In addition, the influence of the supply stirring roller 35 is reduced, and the effect of regulating the developer amount is enhanced. In particular, since the developer to be conveyed by the supply stirring roller 35 is regulated by the regulation member 45 not at the top but before that, a part of the ascending flow accompanied by the vicinity of the tip of the supply stirring roller 35 is generated. Stopped,
Since the developer is returned to the opposite side, the result is that the spiral flow as shown in FIG. 1 is better formed. Thereby, the stirring effect of the developer is also enhanced.

Further, at the tip portion of the regulating member 45, the surface 45a on the downstream side in the rotational direction of the supply stirring roller 35, that is, the developing roller 34 side, is inclined toward the upstream side. By forming this inclined surface 45a, the regulating member 45
As described above, the developer regulated in (1) is returned to the upstream side that flows in from the stirring chamber 33 side, while the remaining developer passing through the regulation member 45 accompanies in the vicinity of the tip portion of the supply stirring roller 35. There is no resistance to the flow of developer. Therefore, it smoothly passes through the regulation part. Therefore, sufficient stirring and conveyance can be performed without disturbing the flow state of the developer at the position of the regulating member 45.

In this case, since the flow of the developer is formed along the inclined surface 45a of the regulating member 45, a good spiral flow is also formed on the developing roller 45 side as shown in FIG. As a result, the recovered developer can be replaced and the developer after stirring can be satisfactorily supplied.

By setting the distance between the tip of the regulating member 45 and the tip of the supply stirring roller 35 according to the second embodiment as shown in Table 2, it is possible to achieve better development. Of course.

(Third Embodiment of the Present Invention) As described above, in the developing device 5 of the present invention, the developing tank 30 is divided into upper and lower parts by the partition member 31, and the developing chamber 32 and the stirring chamber 33 are separated. It is divided into. Therefore, from the developing chamber 32 side, the stirring chamber 3
The developer is sent to the third side, sufficiently stirred and conveyed in the stirring chamber 33, and then returned to the developing chamber 32. At this time, the developer is replenished with toner in a state where the amount of mixed toner, that is, the toner concentration is detected by the concentration detection sensor 44, and a decrease in concentration is detected.

In the toner replenishment, as shown in FIGS. 2 and 4, the toner is supplied to one end of the stirring chamber 33. When performing such replenishment, it is necessary to immediately convey the replenishment toner by the agitating rollers 36 and 37 in the rotation axis direction so as to make a uniform distribution state in the axial direction. That is, when the toner replenished to the one end portion is immediately conveyed in the axial direction, is not stirred and is not uniformly distributed, and is supplied to the developing roller 34, a portion where the toner concentration is high occurs partially. When the image is developed, it results in an unbalance of the image development density and deterioration of image quality such as fogging.

Therefore, in the present invention, as shown in FIG. 2, the screw blade 36 having a spiral shape so that the replenishment toner can be immediately conveyed in the axial direction of the stirring rollers 36 and 37.
a and 37a are provided. By using such a screw blade, the developer carrying capacity is improved. Therefore, the replenished toner is conveyed while being mixed with the developer, the conveyance in the axial direction is fast, and the effect of uniformly distributing the replenishment toner in the axial direction is enhanced.

Further, in the present invention, an example for immediately performing uniform mixing and uniform distribution of toner will be described below.

In FIG. 4, the flow of the developer is shown in the stirring chamber 3
It flows in the arrow direction on the 3 side and the developing chamber 32 side. As can be understood from the drawing, the first stirring roller 3 on the stirring chamber 33 side
Reference numeral 6 conveys the toner replenished P to the end portion on the front F side in the direction of the arrow, and simultaneously conveys the developer 22a fed from the developing chamber 31 side to the rear (back) R side.
Then, the original material conveyed to the back side passes through the passage port 42a, is fed to the second stirring roller 37 side, and is conveyed to the front F side by the second stirring roller 37.

During the transportation, the developer is transferred to the developing chamber 32.
22b. Further, the developer conveyed to the front F side is sent to the first stirring roller 36 side via the passage port 42a.

Further, the developer 22 returned to the developing chamber 32
As shown in FIG. 4B, b is the developer 22e collected by the supply stirring roller 35 after the development of the developing roller 34.
At the same time, the developer 22c is agitated. in this case,
A part of the developer is supplied to the developing roller 34 as the developer 22d while being conveyed from the rear (rear) side R of the developing chamber 31 to the front F side.

Here, the conveying direction of the developer by the second stirring roller 37 on the side of the stirring chamber 33 is the same as the conveying direction of the developer by the supply stirring roller 35, and the developer is on the front F side. The amount of the developer that is supplied to the developing roller 34 in a collected state and is conveyed by the rotation of the developing roller 34 increases on the front side. And blade 3
The amount of the developer regulated by 8 and fed to the stirring chamber 32 side increases on the front F side.

As a result, when toner P is supplied to the end portion on the front F side as shown in FIG. 2, a large amount of developer is immediately conveyed in the axial direction by the first agitating roller 36, and a large amount of developer is conveyed. Since the toner can be agitated with the developer, the replenished toner can be agitated and mixed into the developer, and the toner distribution state in the transport axis direction can be made uniform in a short time.

That is, as in the present invention, when the developer is sent to the upper stirring chamber 33 in the upper and lower developing tanks 30 and sent back from the stirring chamber 33 to the lower developing chamber 32 side, In the place where the toner is replenished, the upper stirring chamber 33 side is naturally the most suitable. Further, if toner is supplied to the entire axial direction of the first and second agitating rollers 36 and 37 at the replenishment position, the toner is mixed with the entire developer and agitated to obtain a uniform distribution state. Can be maintained.

However, when supplying to one end on the side of the stirring chamber 33, for example, the front F end (or the rear R end), uniform distribution takes time. However, as in the present invention, if the developer is concentrated and sent to the position where the toner is replenished, it can be agitated and conveyed so that the time becomes a uniform distribution state in a short time.

Therefore, as one example, the conveying direction of the second stirring roller 37 of the stirring chamber 33 on the toner replenishing side and the conveying direction of the supply stirring roller 35 on the developing chamber 32 side are set at one end to which toner is replenished. It is configured to be conveyed in the direction of the section. As a result, as described with reference to FIG. 4, the developer can be concentrated and conveyed to the end portion side where the toner is replenished, so that a large amount of the developer is sent to the toner replenishment position and the first stirring roller is supplied. At 36, the toner is immediately conveyed in the opposite direction, and the replenishment toner can be mixed and agitated while being conveyed in the axial direction. Therefore, it is possible to mix the toner with the developer and obtain a uniform distribution state. Can be shortened.

By carrying the developer as described above in the developing device 5 configured as in the present invention, the toner is replenished, and the time during which the distribution state of the replenished toner becomes uniform was confirmed. . To confirm this, the developer conveying direction by the supply stirring roller 35 is changed to, for example, in FIG.
FIG. 9 shows the result of an actual experiment as a comparative example, which is configured to be transported from the front F side to the rear R side.

In FIG. 9, a developer having a high toner concentration is filled in the front F side of the developing tank 30, and a developer having a low toner concentration is filled in the rear R side, and the first and second agitating rollers 3 are filled.
6 and 37, the developing roller 34, and the supply stirring roller 35 were driven in the same manner as in the case of developing. Further, in the present invention, when the developer is conveyed in the direction shown in FIG. 4, the toner concentration in the developing tank 30 is uniformly distributed over the entire area for about 40 seconds.

On the other hand, in FIG. 4, when the conveying direction of the developer by the supply stirring roller 3 is reversed, it takes about 50 seconds as shown as a comparative example. According to the configuration of the present invention, it was confirmed that the time required for uniform distribution was shortened as compared with the comparative example.

In the developer conveying direction of FIG. 4, the conveying force in the axial direction is only in one direction, and the developer is excessively concentrated at one end at the end portion in the conveying direction, so that the developing Uneven distribution of developer in the tank 30, local pressure increase,
And a developer to the bearing portion 29 that supports the shaft of each roller,
There is a risk that toner, etc. will enter.

Therefore, as shown in FIG. 2, for example, the first
In the second agitating rollers 36 and 37, a sub-transport unit 36b that transports the developer in the direction opposite to the transport direction in the vicinity of the side wall of the developer tank 30 in the developer transport direction indicated by the arrow.
37b is provided. Further, a feeding piece 3 for positively feeding the developer to the first or second agitating rollers 36, 37 facing each other corresponding to the sub-transport portions 36b, 37b.
6c and 37c are provided.

Further, in the supply stirring roller 35 shown in FIG. 3, the developer is conveyed from the rear side to the front side in FIG. 4, and at the end portion in the conveying direction, the developer is developed in the opposite direction. A sub-transport unit 35e for transporting the agent is provided.

With the above-described structure, the developer is conveyed in the opposite direction to the main conveying direction on the end side where the developer is conveyed as shown in FIG. It will be. It is possible to solve the above-mentioned problem that the developer is excessively concentrated on the side wall of the developing tank 30. Moreover, since the feed pieces 6c and 37c provided on the first and second agitation rollers 36 and 37 are provided, the developer concentrated in the position can be immediately fed to the other party, and the problem caused by the concentration can be prevented. The effect of eliminating can be promoted.

As a result, the developer is concentrated and sent to the toner replenishing section, and the problems due to the concentration can be eliminated, the developer can be efficiently conveyed, and the toner density distribution can be achieved in a short time. You can do it. In this case, at least the second agitating roller 37 and the sub-conveying portions 37b and 35e of the supplying and agitating roller 35 may be provided on the portion where the developer is likely to concentrate, particularly on the toner replenishing portion P side, and if necessary The sub-transport unit 36a of the first stirring roller 36 may be provided.

As described in the first and second embodiments together with this embodiment, the time for uniformizing the toner distribution is provided by additionally providing the developer regulating member 45 provided on the developing chamber 32 side. Can be shortened and the distribution can be stabilized.

Further, the first and second stirring rollers 36, 3
The transport amount of the developer by the sub transport units 36b and 37b of 7 is
The size is smaller than that of the main transport section. for that reason,
The effective diameter and the conveyance pitch of the rotary spiral forming the sub-conveyance parts 36b and 37b and the sub-conveyance part 35e of the supply stirring roller 35 are set smaller than those of the main conveyance part. As a result, the developer concentrated on the side wall of the developing tank 30 can be sent in the opposite direction, the developer can be efficiently transported, and the effect of uniformly distributing the toner after replenishment can be shortened.

Further, the first and second agitating rollers 36 and 37 on the agitating chamber 33 side distribute the replenished toner uniformly to the developer and positively apply the developer to shorten the time. The carrying capacity is set to be large so that the carrying force and the carrying speed are increased in the opposite directions. On the other hand, on the side of the lower developing chamber 32, when the developer is conveyed in one direction by the supply stirring roller 35,
The agitating roller 37 on the agitating chamber 33 side has a conveying ability in that direction.
If the conveyance capacity is set to be equal to
One side wall side is unevenly distributed and excessively concentrated. for that reason,
It is preferable that the developer carrying capacity of the supply stirring roller 35 is set to be smaller than the carrying capacity of the second stirring roller 37 so as to suppress the movement of the developer in the main carrying direction and eliminate uneven distribution of the developer. .

[0131]

According to the developing device of the present invention, the developer can be circulated and conveyed satisfactorily, and the stirring, mixing with the replenished toner and the stirring can be efficiently performed, and the developing chamber and the stirring chamber can be moved up and down respectively. Since it is divided into two parts, the entire developing device can be made compact.

Furthermore, by providing a regulating member on the developing chamber side and at a position facing the agitating member, the flow of a part of the developer can be regulated and the effect of agitating the developer can be enhanced, so that good development can be achieved. It is also possible to prevent the developer from excessively accumulating on the developing chamber side. As a result, good agitation can be achieved, the time for starting the developing device does not become long, the drive torque does not increase, and the image quality defect due to insufficient developer can be eliminated.

At the same time, a spiral flow of the developer is formed on both sides of the regulating member to improve the stirring efficiency, and the recovered developer can be replaced well, and good development can be maintained, and at the same time, the developer can be maintained. The period of deterioration of the developer can be extended by shortening the stirring time.

[0134]

[Brief description of drawings]

FIG. 1 is a sectional view showing an internal structure of a developing device for explaining a first embodiment according to the present invention.

FIG. 2 is a plan view showing an arrangement state of a stirring roller that constitutes a stirring chamber for stirring and conveying a toner replenishing portion and a developer of the developing device shown in FIG.

FIG. 3 is a perspective view showing a configuration example of a supply stirring roller that constitutes a developing chamber of the developing device shown in FIG.

4A and 4B are for explaining the flow of the developer in the developing tank of the developing device in FIG. 1, where FIG. 4A shows the flow of the developer on the stirring chamber side, and FIG. 4B shows the flow on the developing chamber side. It is explanatory drawing which shows the flow of a developer.

FIG. 5 is a cross-sectional view showing the flow of the developer when the flow of the developer shown in FIG. 4 according to the first embodiment of the present invention is viewed from the side.

6 is a configuration diagram showing an internal structure of an image forming apparatus including the developing device shown in FIG.

FIG. 7 is a diagram for explaining a suitable position where a regulating member is provided in the developing device of the present invention.

FIG. 8 is a diagram showing a developing device according to a second embodiment of the present invention, and is a diagram for specifically explaining the arrangement state of the regulating member.

FIG. 9 is a characteristic diagram showing a state in which the replenishment toner by the developing device according to the third embodiment of the present invention is uniformly distributed according to the stirring time.

FIG. 10 is a diagram for explaining a developer conveying direction and a flow thereof in the developing device according to the third embodiment of the present invention.

FIG. 11 is a diagram showing a basic configuration in which a developing tank of a developing device according to the present invention is vertically divided into two parts, and a state of a developer.

[Explanation of symbols]

1 Copier (image forming device) 2 photoconductor (image carrier) 5 Development device 30 developer tank 31 Partition 32 development room 33 stirring chamber 34 developing roller 35 Supply stirring roller (stirring member) 35e Sub transport unit 36 First Agitation Roller (First Conveying Means) 36a screw wing 36b Sub transport unit 37 Second stirring roller (second conveying means) 37a screw wing 37b Sub transport unit 38 Regulation blade 40 intake 41 baffle 42 Passage 43 Return port 45 Control member 45a inclined surface 46 space P Toner supply section

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Europe Waka, 22-22 Nagaike-cho, Abeno-ku, Osaka-shi, Osaka Prefecture Sharp Corporation (72) Inventor Naotaka Funayama 22-22, Nagaike-cho, Abeno-ku, Osaka City, Osaka Sharp Corporation (56) References JP-A 59-140473 (JP, A) Actual development 63-35061 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) G03G 15/08 110 G03G 15/08 504 G03G 15/08 507

Claims (4)

(57) [Claims] 1. A developer carrying member carrying a developer containing toner and carrying the developer to the image carrying member side is provided in a developing tank, and the developing tank is divided into upper and lower partitions to bisect the developing area. A developing chamber equipped with a developer carrying member, and a stirring chamber equipped with a carrying unit for agitating and carrying the developer in the upper region, and a regulating unit for regulating the amount of the carried developer carried by the developer carrying member. In order that the developer regulated by the above may be sent to the stirring chamber side, a space between the tip of the partition portion and the regulating means is formed as an intake port, and the partition portion on the stirring chamber side may have In a developing device having a return port for returning the developer to the developing chamber side and circulating the developer between the developing chamber and the stirring chamber, the developing chamber side corresponding to the returning port is used for developing. The developer is agitated and the developer is supplied to the developer carrier side. A stirrer means for controlling the flow of the developer, one end of which is provided in the partition portion on the side of the developing chamber, and the other end of which faces the stirrer to restrict the flow of the developer. One provided to face
The end is placed close to the top of the stirring means.
Developing apparatus is characterized in that is. 2. An image bearing member side carrying a developer containing toner.
The developer carrier to be transported to the developing tank is provided in the developing tank, and the developing tank is
The above-mentioned development is performed in a lower area which is divided into two by providing partition sections on the top and bottom
The developer chamber is equipped with a developer carrier, and the developer is stirred in the upper area.
The stirring chamber is equipped with a transporting means for stirring and transporting, and the amount of the transported developer carried on the developer carrying body is adjusted.
The developer regulated by the regulation means is regulated by the stirring chamber side.
And the regulating means so that
Is formed as an inlet between the developing chamber and the partition on the side of the stirring chamber.
A return port for sending back the developer is provided between the developing chamber and the stirring chamber.
In the developing device configured to circulate between the above, the developer is agitated to the developing chamber side corresponding to the return port, and
A stirring means is provided to supply the developer to the image carrier.
One end is provided in the partition section on the developing chamber side,
A rule that regulates the flow of the developer with its end facing the stirring means.
A restriction member is provided, and one end portion of the restriction member, which is provided so as to face the stirring means, is arranged at a certain distance to the upstream side of the developer flowing direction from the top of the stirring means. current image device characterized. Wherein one end of the regulating member, according to claim 2, characterized in that inclined surface toward the upstream side in the direction of flow of the developer in the developer bearing member is formed
The developing device described. 4. The one end portion of the restriction member provided to face the stirring means has a gap of 1.5 from the stirring means.
3. The developing device according to claim 1 , wherein the developing device is set to be equal to or less than mm.