JPH02205875A - Developing device - Google Patents

Abstract

PURPOSE:To enable a magnet to be reused with simple constitution by supporting the magnet rotatably on an image forming device main body and forming a developing sleeve and a developing unit package in one body. CONSTITUTION:The developing sleeve 3 and developing unit package 2 are formed in one body and the sleeve 3 is so fixed not to rotate. Further, when the developing unit package 2 is set on a copying machine main body, the magnet which is constituted as a magnet roller 4 is inserted and positioned in the developing sleeve 3, and this magnet roller 4 is supported on the copying machine main body 7 and driven clockwise. Consequently, the magnet 4 can be used again and the structure of the developing unit package 2 is simplified to reduce the cost.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention carries a developer on a developing sleeve in which a magnet is located and conveys the static image formed on a latent image carrier by the developer. The present invention relates to a developing device that visualizes an electrostatic latent image.

[Conventional technology]

2. Description of the Related Art It has been well known to use a developing device of the above type in an image forming apparatus such as an electronic copying machine, a facsimile machine, or a printer. In this type of developing device, developer is carried on a developing sleeve.

A magnet is installed inside the developing sleeve for the purpose of conveying the developing agent or regulating the layer thickness of the developer on the developing sleeve.

On the other hand, recent image forming apparatuses have adopted a so-called disposable type developing device, in which the developing device is detachably attached to the main body of the image forming apparatus and replaced with a new one as needed. There is. For example, in a developing device using a -component developer.

When the developer is completely consumed or the amount remaining is low, the developing device is replaced with a new one. Further, in a developing device using a two-component developer, when the carrier deteriorates, a typical example is to replace it with another developing device. According to this type of developing device,
The user does not have to replace the developer, and the management thereof can be simplified.

By the way, the above-mentioned magnet that constitutes the developing device costs 20 to 50 percent of the price of the entire developing device, not including the rolling motor.
It is an expensive part that accounts for 30% of the total cost.

Therefore, if such expensive parts were to be discarded when replacing a disposable type developing device, it would place a great economic burden on the user.

Therefore, a developing sleeve is attached to a developing unit package containing developer to form a unit, and this unit and a magnet are separate parts, and the developing unit package is supported detachably from the main body of the image forming apparatus. , a developing device in which the magnet is supported on the image forming apparatus main body side has been proposed (Japanese Patent Laid-Open No. 164577/1983). When replacing the developing device, the developing sleeve and developing unit package are removed from the image forming apparatus main body and a new Replace it with a new one, but leave the magnet in the image forming apparatus itself. In other words, even after replacing the developing unit package, the previous magnet is used again. In this way, the expensive magnet can be used many times, reducing the economic burden on the user.

[Problem to be solved by the invention]

By the way, in the developing device disclosed in Japanese Patent Application Laid-Open No. 59-164577 mentioned above, a developing sleeve carrying developer is rotatably incorporated into a developing unit package, and the developing unit package is set in the main body of the image forming apparatus. The developing sleeve is configured to be rotationally driven by a drive device on the image forming apparatus main body side when the image forming apparatus is opened. That is, the developing sleeve and the developing unit package are separate members, and a unit in which the sleeve is rotatably assembled to the developing unit package is used by setting it in the main body of the image forming apparatus.

However, according to this configuration, when manufacturing the developing device, the separately manufactured developing unit package and developing sleeve are
Since it needs to be assembled through bearings, it is time-consuming to assemble it. Furthermore, a gear must be attached to the developing sleeve to rotate it. Since bearings and gears are required in this way, the total number of parts increases and the cost increases.

When replacing the developing device, both the expensive developing unit package and the developing sleeve are discarded, so even though the magnets are reused, the economic burden on the user cannot be sufficiently reduced.

The above-mentioned drawback will be referred to as the first drawback.

Next, when using a two-component developer consisting of toner and carrier in a developing unit package, in order to improve the quality of the developed visible image, the developer in the developing unit package must be sufficiently stirred. .

It is necessary to triboelectrically charge the toner particles and carrier particles to a predetermined polarity. For this reason, in the developing device disclosed in Japanese Patent Application Laid-Open No. 59-164577, a plurality of stirring rollers made of magnets are provided outside the developing unit package, and the developer inside the developing unit package is stirred by the rotation of the stirring rollers. There is. However, if an agitation roller is provided outside the developing unit package to agitate the developer, the agitation efficiency may be poor, leading to insufficient agitation of the developer.

Therefore, it is necessary to increase the number of stirring rollers to prevent insufficient stirring of the developer, but this increases the cost of the developing device. This conventional drawback will be referred to as the second drawback.

Furthermore, when the developing unit package with the assembled developing sleeve is removed from the image forming apparatus main body when replacing the developing device, the magnets left on the image forming apparatus main body are supported in a cantilevered manner by the image forming apparatus main body. However,
At this time, the free end side of the magnet may be elastically bent and deformed due to the magnet's own weight or magnetic force. If the magnet is deformed in this way, it becomes difficult to assemble a new developing unit package to the magnet, reducing work efficiency.

In a developing device that uses multiple magnets adjacent to each other, the magnets left in the main body of the image forming device attract or repel each other due to magnetic force, so there is a risk that these may be bent and deformed significantly, and the above-mentioned problems can be avoided. This is particularly likely to occur. This conventional drawback will be referred to as the third drawback.

Next, when the developing unit package is removed from the image forming apparatus main body, the magnet is pulled out from the developing sleeve.
It is left in the image forming apparatus main body in a naked state. For this reason, there is a risk that developer or other foreign matter made of magnetic material that has fallen onto the main body of the image forming apparatus will be directly attracted to the bare magnet by magnetic force, resulting in the magnet becoming dirty. Furthermore, if a developing operation is performed with foreign matter attached to the magnet, there is a risk that the foreign matter will generate abnormal noise and slip when the magnet or developing sleeve rotates. Furthermore, if a tool or the like hits a bare magnet, there is a risk that the magnet will be damaged.

This drawback will be referred to as the fourth drawback.

The present invention has been made in view of the various problems mentioned above, and its object is to provide a developing device that eliminates the above-mentioned first to fourth drawbacks with a simple configuration.

[Means to solve the problem]

In order to eliminate the above-mentioned first drawback, the present invention provides a developing unit package which is detachably supported by an image forming apparatus main body and which contains a developer therein, and which is provided in the developing unit package. A developing sleeve that carries a developer for visualizing an electrostatic latent image formed on a latent image carrier, and a developing unit package that is inserted into the developing sleeve when the developing unit package is set in the main body of the image forming apparatus. and a magnet supported by the image forming apparatus main body, and when the developing unit package is removed from the image forming apparatus main body, the developing sleeve is removed from the image forming apparatus main body together with the developing unit package. is,
In a developing device, the magnet is left supported on the image forming apparatus main body side.

The present invention proposes a developing device, wherein the magnet is rotatably supported by an image forming device main body so as to be rotationally driven by a drive device, and the developing sleeve is integrally formed with a developing unit package.

At this time, the inside of the developing unit package is partitioned into a toner tank containing toner and a agent tank containing a two-component developer consisting of toner and carrier, and the developing sleeve is located on the side of the agent tank, The toner in the toner tank is supplied to the two-component developer on the developing sleeve via a toner supply roller supported by the development unit package, and the toner supplied from the toner tank is supplied to the toner supply roller within the tank. It is advantageous that a leveling member is provided in the developer tank to correct uneven distribution of the two-component developer stored in the developer tank, which is triboelectrically charged by a friction member that presses against the upper toner.

Further, in order to eliminate the above-mentioned second drawback, the present invention provides a developing unit package which is detachably supported by the main body of an image forming apparatus and which contains a two-component developer therein, and which is provided in the developing unit package. A developing sleeve that carries a developer for visualizing an electrostatic latent image formed on a latent image carrier, and a developing unit package inside the developing sleeve when it is set in the image forming apparatus main body. and a magnet that is inserted into the image forming apparatus and supported on the image forming apparatus main body side, and an agent stirring means that stirs the two-component developer in the developing unit package, and the developing unit package When detached from the image forming apparatus main body, the developing sleeve is removed from the image forming apparatus main body together with the developing unit package, and the magnet remains supported on the image forming apparatus main body side. A developing device characterized by being installed inside a package is proposed.

Furthermore, in order to eliminate the third drawback mentioned above, the present invention provides a developing unit package that is detachably supported by the main body of an image forming apparatus and contains a developer therein, and a developing unit package that is provided in the developing unit package. , a developing sleeve that carries a developer for visualizing an electrostatic latent image formed on a latent image carrier, and a developing unit package that is inserted into the developing sleeve when it is set in the image forming apparatus main body. and a magnet supported by the image forming apparatus main body, and when the developing unit package is removed from the image forming apparatus main body, the developing sleeve is removed from the image forming apparatus main body together with the developing unit package. In the developing device, the magnet is supported in a cantilevered manner by the image forming apparatus main body, and the developing unit package is removed from the image forming apparatus main body. In this case, the present invention proposes a developing device characterized in that a magnet holder is disposed to support a magnet portion other than the support portion of the magnet.

In this case, it is advantageous if the magnet holder is supported so as to be movable in the direction of attachment and detachment of the developing unit package when the package is attached and detached.

The present invention also eliminates the fourth drawback mentioned above.

In addition to the above configuration, one end side is fixed to the magnetic holder and the other end side is fixed to the image forming apparatus main body side, so that when the developing unit package is removed from the image forming apparatus main body side, one end remains on the image forming apparatus main body side. We propose a configuration in which a stretchable cover is provided to cover at least a portion of the magnet.

[Example] Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a sectional view showing an example of a developing device in an electronic copying machine.

In the figure, a developing device 1 includes a developing unit package 2 containing a developer therein, and a developing sleeve 3 made of a non-magnetic material provided in the package 2. expose a part of the
The photosensitive drum 6, which is an example of a latent image carrier, is rotatably supported by an image forming apparatus main body (in this example, a copying machine main body), and is opposed to the photosensitive drum 6 with a predetermined gap therebetween.

As will be described later, the developing sleeve 3 is formed integrally with the developing unit package 2, and the sleeve 3 is fixed non-rotatably. Furthermore, when the developing unit package 2 is set in the copying machine main body 7 (FIG. 2) as shown in FIG.
The magnet roller 4 is positioned with a magnet configured as inserted therein, and the magnet roller 4 is supported by the copying machine main body 7, as will be described later, and is driven to rotate clockwise in FIG. As shown in FIG. 1, the magnetic poles S and N of the magnet roller 4 are magnetized so as to alternately have different polarities in the circumferential direction of the roller 4.

Further, in the embodiment shown in FIG. 1, the inside of the developing unit package 2 includes a toner tank 8 containing toner T;
A partition wall 10 separates the developer tank 9 from a two-component developer containing a magnetic carrier and toner.

At this time, the developing sleeve 3 is located on the side of the developer tank, and the developer is supported on its circumferential surface by the magnetic force of the magnet roller 4. The toner is a powder consisting of toner particles alone or with additives added thereto.

During the developing operation, the magnetic roller 4 is rotated clockwise, and the developer carried around the immovably fixed developing sleeve 3 is rotated in the opposite direction to the rotating direction of the magnetic roller 4, that is, as shown in FIG. Conveyed counterclockwise. that time.

The conveyance amount of the developer is regulated by a doctor blade 11 attached to the developing unit package 2, and a predetermined amount of the developer is transferred to the opposing area between the photosensitive drum 6 and the developing sleeve 3, which rotate clockwise, that is, the developing area A. There, the toner contacts the surface of the photoreceptor drum 6, and the toner being developed electrostatically transfers to the electrostatic latent image formed on the photoreceptor drum 6.
The latent image is made visible.

The developer that has passed through the development area A is further conveyed counterclockwise and returned to the developer tank 9.

On the other hand, the toner in the toner tank 8 is agitated by the agitator 12 that swings in the direction of arrow B, and blocking thereof is prevented. A toner replenishment roller 13 supported by the developing unit package 2 and driven to rotate clockwise is located at the lower opening of the toner tank 8 that communicates with the developer tank 9 . A fixed friction member 14 is arranged, and the member 14 presses against the toner on the toner supply roller 13.

As the toner supply roller 13 rotates clockwise, the toner T in the toner tank 8 is discharged from the toner tank 8 in a predetermined amount while being carried on the surface of the roller 13 . At this time, the toner on the toner supply roller 13 rubs against the friction member 14 and is frictionally charged to a predetermined magnetism. This causes the toner to electrostatically adhere to the surface of the toner supply roller 13.

The toner tank 8 is transported by the rotation of the roller 13.
is discharged from. This toner comes into contact with the developer on the developing sleeve 3 that has passed through the developing area A as described above, and at this time, it electrostatically adheres to the carrier in the developer that is charged to the opposite polarity to the toner, and the developer It becomes part of the liquid and is transported into the agent tank 9. In this way, the toner T in the toner tank 8 is transferred to the developing sleeve 3 via the toner supply roller 13.
It is supplied to the two-component developer above.

Note that the rotational speed of the toner replenishing roller 13 is made faster than the conveyance speed of the developer on the developing sleeve 3, and the toner on the roller 13 is conveyed at a higher speed than the developer.
By supplying this to the developer, it is possible to prevent the occurrence of insufficient toner supply, and also to bring the supplied toner into strong contact with the carrier in the developer, improving the triboelectric charging efficiency of both. It is possible. In addition, in the example shown in FIG. 1, the moving direction of the developer on the developing sleeve 3 and the rotating direction of the toner replenishing roller 13 are set in the forward direction, but the rotating direction of the roller 13 is set in the opposite direction to the developer conveying direction. You may set it so that. The lower end of the partition wall 10 that partitions both tanks 8 and 9 strongly contacts the circumferential surface of the toner supply roller 13 to prevent developer from entering the toner tank 8 .

Further, a leveling member 15 supported by the developing unit package 2 is disposed in the agent tank 9.
5 consists of a shaft 16 with a number of inclined disks 17 fixedly attached thereto, as shown in FIG. The leveling member 15 is rotated, for example, in the clockwise direction in FIG. 1, and the rotation of the inclined disk 17 transports the developer in the developer tank 9 so as to level it in the left-right direction in FIG. The developer is stirred to correct uneven distribution of the developer in which the developer is present unevenly on either the left or right side in the developer tank 9. Thereby, the surface of the developer layer can be made substantially flat.

In addition, the leveling member 15 stirs the developer in the developer tank 9,
In place of the leveling member having six discs 17, which also serves as agent stirring means for triboelectrically charging the toner particles and carrier to predetermined polarities, a leveling member consisting of a screw is used, and this is rotated to stir the developer. It may also be configured to smooth out the curves.

The above-mentioned elements of the developing device 1 configured as described above, except for the magnet roller 4, are integrally assembled and constitute a disposable developing unit 18. For example, when the developer carrier contained in the developer tank 9 of the developing unit package 2 deteriorates, the entire developing unit 18 may be replaced with another developing unit containing developer containing new carrier. can. In this way, when a method is adopted in which the developing unit 18 is replaced when the carrier deteriorates, when the toner tank 8 runs out of toner or its remaining amount is low, a Open the lid 19 and refill toner from here.

It is also possible to adopt a system in which, when the toner in the toner tank 8 runs out, the developing unit 18 is replaced with another developing unit that is full of toner. In any case, since the developing unit 18 can be replaced, the user does not have to replace the developer or replenish the toner, and the management thereof can be simplified.

In order to make the developing unit 18 replaceable as described above, the developing unit package 2 containing a developer therein is detachably supported on the copying machine body 7. In this example, a slider 20 is fixed to the earthen wall of the developing unit package 2, and is slidably fitted into a guide rail 21 fixed to the copying machine main body 7 side.

When replacing the developing unit 18, move it in the direction perpendicular to the page of FIG. 1, that is, to the right in FIG.
direction). At this time, the slider 20 slides on the guide rail 21 and finally comes off the rail 21. In this manner, the developing unit package 2 together with the developing sleeve 3, that is, the entire developing unit 18 can be removed from the copying machine main body 7 as shown in FIG.

At this time, the magnet roller 4 is separated from the developing unit package 2 and remains supported by the copying machine main body 7. That is, as clearly shown in FIG.
The base end side (inner side) is rotatably supported by a support frame 23 of the copying machine main body 7 and a support bracket 24 fixed to the support frame 23.

In this way, the magnet roller 4 is supported by the copying machine main body 7, and the developing unit package 2 is attached to the main body 7 as shown in FIG.
is inserted into the sleeve 3 from the opening 25 on the back side of the developing sleeve 3,
At this time, the front end side (right end side in FIG. 2) of the shaft 22 of the magnet roller 4 is rotatably but removably supported by the bearing portion 26 of the developing unit package 2 via a bearing. Further, a gear 27 is fixed to the shaft base end side of the magnet roller 4.

An intermediate gear 28 rotatably supported by the support bracket 24 of the copying machine main body 7 meshes with the intermediate gear 28, and the gear 28 is rotationally driven by a drive device including, for example, a motor (not shown) via a transmission member such as a pulley. As a result, the magnet roller 4 is rotationally driven as described above.

When the developing unit 18 is removed from the copying machine main body 7 as described above, the magnet roller 4 remains on the copying machine main body 7 side, and the front end of the shaft 22 comes off from the bearing portion 26 of the developing unit package 2. At this time, the magnet roller 4 is supported by the copying machine main body 7 in a cantilevered manner, and the roller 4 tends to tilt downward toward the free end side, so in this example, the axis of the magnet roller 4 is The proximal end is supported at two locations: the support frame 23 and a support bracket 24 spaced apart from the support frame 23, thereby preventing the magnet roller 4 from tilting.

When setting a new developing unit 18 in the copying machine main body 7, align the opening 25 of the developing sleeve 3 with the magnet roller 4, and move the slider 20 onto the guide rail 21.
the developing unit package 2 on the back side (second
(in the opposite direction of arrow C in the figure), and
The positioning protrusion 29 on the back side fits into the positioning groove 30 formed in the support frame 23. As a result, the developing unit package 2 is positioned and fixed to the copying machine main body 7.

Further, as shown in FIG. 2, the previously described leveling member 15 has a shaft 16 whose rear end region rotatably penetrates the side wall of the developing unit package 2, and a front end region of the shaft 16. The end portion of the shaft 16 is rotatably supported by a bearing portion 31 of the developing unit package 2, and a gear 32 is fixed to the rear end portion of the shaft 16. This gear 32 meshes with an intermediate gear (not shown) supported by the support frame 23 and rotationally driven by a drive device when the developing unit package 2 is set in the copying machine main body 7 as described above.

Alternatively, the intermediate gear may be brought into contact with the gear 32 when the developing unit package 2 is set, and the two gears may be engaged with each other as the intermediate gear starts rotating. After the developing unit package 2 is set in the main body 7 in this manner, the leveling member 15 can be rotated as described above.

The toner replenishing roller 13 and the agitator 12 are also rotatably supported by the developing unit package 2 in the same way as the leveling member 15, and a gear (not shown) attached to the back side of the developing unit package 2 moves the developing unit package 2 into the main body of the copying machine. When set to 7, it is connected to a gear on the main body of the copying machine and is driven by a drive device.

When the developing unit 18 is removed from the copying machine main body 7 as shown in FIG. 4, the magnetic roller 4 remains supported by the main body 7, so when a new developing unit 18 is set, the magnetic roller 4 can be used again. can. In this way, although the unit 18 consisting of the developing unit package 2, the developing sleeve 3, etc. is replaced and the old unit 18 is discarded, the magnetic roller 4 can be used any number of times, so the cost borne by the user can be reduced. Further, when replacing the developing unit 18, there is no need to carry the magnet roller 4, and since the lightweight developing unit 18 without the roller 4 can be attached and removed, its handling becomes easier. Such advantages can basically be similarly obtained in the developing device described in Japanese Unexamined Patent Publication No. 59-164577. However, as described above, in the developing device disclosed in this publication, the developing sleeve is rotatably supported with respect to the developing unit package, which increases the cost of the developing unit itself.

Therefore, in the developing device according to the present invention shown in FIGS. 1 to 3, as described above, the magnet roller 4 is rotatably supported by the copying machine main body 7 so as to be rotationally driven by the driving device, and the developing device is The magnetic roller 4 is rotated during operation to convey the developer on the developing sleeve 3, and the developing sleeve 3 is integrally formed with the developing unit package 2. Therefore, when manufacturing the developing device, there is no need to rotatably assemble the developing sleeve 3 to the developing unit package 2 via a bearing, and it is also necessary to attach a gear to the sleeve 3 for rotationally driving the developing sleeve 3. Nor. Therefore, the number of parts of the developing unit 18 can be reduced, and the manufacturing cost thereof can be reduced. It is also possible to integrally mold the developing unit package 2 and the developing sleeve 3 using synthetic resin, and in this way there is no need to assemble the developing unit package 2 and the developing sleeve 3, which greatly reduces the cost. can.

Although it is not necessary to provide the gear to the developing sleeve 3 as described above, it is necessary to provide the gear 27 to the magnet roller 4, which increases the cost.

However, even if the developing unit 18 is replaced repeatedly, the gear 27 can be used many times like the magnet roller 4 and does not need to be disposed of, so the economic burden on the user can be reliably reduced.

The developing sleeve 3 placed opposite to the photoreceptor drum 6 functions as a counter electrode, but when the developing sleeve 3 and the developing unit package 2 are integrally molded from synthetic resin as described above, as shown in FIG. As shown in FIG. 2, a conductive sheet-like electrode 33 made of, for example, aluminum may be embedded in at least the portion of the developing sleeve 3 facing the photosensitive drum 6, or such an electrode may be printed using printing technology. When applying a bias voltage to the electrode 33, when the developing unit 18 is set in the copying machine main body, a terminal (not shown) of the electrode 33 provided on the side of the unit 18 and a power supply (not shown) on the side of the copying machine main body 7 are connected. (not shown)
The configuration may be such that a terminal (also not shown) connected to the electrode 33 is brought into contact with the electrode 33 and a voltage is applied to the electrode 33.

Note that the terminals of a sensor (not shown) that detects the remaining amount of toner T in the toner tank 8 and the terminals of a sensor (not shown) that detects the toner concentration of the developer in the agent tank 9 are also the same. These terminals are attached to the developing unit package 2 and configured so that when this is set in the copying machine main body 7, these terminals come into contact with the mating terminals on the main body 7 side.

By the way, if the developing unit 18 is removed from the copying machine main body 7 while the developer is carried on the developing sleeve 3, a magnetic force acts on the developer in the developing sleeve 3 as the magnetic roller 4 is removed from the developing sleeve 3. As a result, there is a risk that the developer may spill out from the opening 5. For this reason, in this example, as shown in FIG.
A plunger of a solenoid 35 fixed to the developing unit package 2 is connected to the developing unit package 2 via a tension spring.

When the developing operation is performed as described above, the solenoid 35
is energized, which causes the doctor blade 11 to move to the first position.
It is lifted to the upper position shown by the solid line in the figure, and regulates the amount of developer transported. When the developing operation is completed, the solenoid 35 is deenergized, but at this time, the tension spring 36 stretched between the arm 34 and the developing unit package 2 pulls the arm 34 downward, causing the blade 11 to move as shown in FIG. The developing sleeve 3 is brought into contact with the surface of the developing sleeve 3 as shown by the chain line.

That is, the developer in the developer tank 9 is blocked from the outside.

In the above configuration, when the developing unit 18 is to be removed, the magnetic roller 4 is rotated several times with the solenoid 35 deenergized, that is, with the lower end of the blade 11 in contact with the surface of the developing sleeve 3. , or about 10 times in a clockwise direction. In this way, the developer on the developing sleeve 3 is transferred to the doctor blade 1.
1, the developer no longer exists on the surface of the developing sleeve 3 exposed through the opening 5. If the developing unit 18 is removed after the developer is broken into pieces in this way, there will be no developer at the opening 5, so there will be no chance of the developer spilling out.

Furthermore, although the toner tank 8 of the new developing unit 18 contains toner T in advance, the developer tank 9 may be pre-filled with developer, or the developer tank may be filled with the developer immediately before the unit 18 is set. The developer may be allowed to flow in through an inlet (not shown). In the former case, for example, the developer is sealed in the agent tank 9 at a manufacturing factory of the developing unit 18, but in this case as well, the doctor blade 11 is moved to the position indicated by the chain line in FIG. 1 by the spring 36 as described above. The developing sleeve 3 is held in a state where there is no developer on the surface of the developing sleeve 3 exposed through the opening 5. In this way, developer will not spill out when the developing unit 18 is transported from the factory or when it is set in the copying machine main body 7.

The terminal for the solenoid 35 is also configured to come into contact with a mating terminal on the copying machine main body 7 side when the developing unit 18 is set.

It is also possible to provide a shutter (not shown) that covers the opening 5 and close the opening 5 when the developing unit 18 is attached or detached.

As described above, the developing unit package 2 is divided into the toner tank 8 and the agent tank 9, the toner discharged from the toner tank 8 is charged in advance, and the toner is supplied to the developer on the developing sleeve 3. Although a specific example of a developing device to which the configuration described above is applied, that is, a developing device corresponding to claim 2, has been described, the configuration described in claim 1 is similar to that in which the developing device 221 to the package are placed in two tanks 8.9. A one-component developer consisting only of magnetic toner in the package without dividing it,
Alternatively, the present invention can also be applied to a developing device containing a two-component developer.

Note that the developing device shown in FIGS. 1 to 4 uses charged toner while supplying the developer on the developing sleeve 3, so the amount of developer stored in the developer tank 9 is limited. This has the advantage that it can be reduced in size and the overall structure of the developing device can be made smaller.

Next, FIGS. 5 to 7 show a specific example of a developing device corresponding to claim 3 in which the above-mentioned second drawback is eliminated.

The developing device 1 shown here also includes a developing unit package 2 having a developer tank 109 containing a two-component developer, and a developing sleeve 3 provided in the package 2. In this example, as clearly shown in FIG. 7, the developing sleeve 3 is rotatably supported relative to the developing unit package 2 via bearings 40° 41, and these bearings 40° 41 support the developing sleeve 3 relative to the developing unit package 2. 3 positioning is done. Also.

When the developing unit package 2 is set in the copying machine main body 7 as shown in FIGS. 5 and 7, a gear 42 formed on the back side of the developing sleeve 3 is rotatably attached to the support frame 23 of the copying machine main body 7. It meshes with a gear 43 supported by. A pulley 44 is attached integrally to this gear 43, and a belt 45 is wound around this. The developing sleeve 3 is connected to this belt 45 and gear 43.4.
2, it is rotated counterclockwise in FIG. 5 by a drive device (not shown) on the copying machine main body 7 side.

Further, the bias voltage is applied to the developing sleeve 3 via a gear 43 made of a conductor.
This is done by connecting it to 0. 5 in Figure 7
A seal brush 5 is installed in the developing unit package 2 and comes into contact with the developing sleeve 3, thereby preventing leakage of the developer in the developer tank 109.

When the developing unit package 2 is set in the copying machine main body 7, the magnet 104 inserted into the developing sleeve 3 consists of a plurality of magnets, five magnets 47 in the example shown in the figure. is fixed to a support 48, and the rear end of this support 48 is immovably fixed to the support frame 23 of the copying machine main body 7 and the support bracket 24 fixed thereto, as shown in FIG. ing. That is, in this example, the magnet 104 is fixedly supported by the copying machine main body 7 in a non-rotatable manner. Further, the free end side of the support body 48 is rotatably supported by a bearing member 50 fixed to the front side of the developing sleeve 3.

Thereby, the magnet 104 is positioned with respect to the developing sleeve 3. This member 50 is formed integrally with a lid 58 fixed to the right end of the developing sleeve 3. Since a bias voltage is applied to the developing sleeve 3, its lid 5
8 is preferably made of an insulating material so as to ensure safety even when touched.

A stirring roller 46 is disposed in the developer tank 109 of the developing unit package 2, and developer is accommodated to a height of approximately half the outer diameter of the roller 46.

During the developing operation, the stirring roller 46 and the developing sleeve 3 are each rotated counterclockwise. The rotation of the stirring roller 46 stirs the developer in the agent tank 9, and the toner particles and carrier are each frictionally charged to a predetermined polarity, and the developer is transferred to the developing sleeve 3 by each fin of the stirring roller 46. It is pumped up and fed to the surface of the sleeve 3.

The developer supplied to the developing sleeve 3 is
Due to the rotation of the developer and the magnetic force of the magnet 104 inside the developer, the developer is carried counterclockwise while being supported on the surface of the developing sleeve 3, and the amount of the developer is regulated by the doctor blade 11. The developer that has passed through the blade 11 is transferred to the development area A.
The process of visualizing the electrostatic latent image on the photoreceptor drum 6, which is conveyed and rotated counterclockwise, is the same as in the previous embodiment.

The developer scraped off by the doctor blade 11 flows on the guide plate 51, and a part of it falls, for example, onto the conveying screw 52 that rotates counterclockwise, thereby stirring and mixing the developer, as shown in FIG. is conveyed in a direction perpendicular to the plane of the paper, and finally falls onto the stirring roller 46. By conveying the developer in this manner, it is possible to obtain a triboelectric charging effect on the developer and to prevent uneven distribution of the developer. The other developer flowing on the guide plate 51 is
It falls downward from the right end of the guide plate 51.

A toner tank 108 is formed integrally with a agent tank 109 in the developing unit package 2, and in this example, a toner bottle 53 containing toner T is removably inserted into the tank 108. The agitator 54 in the toner bottle 5 prevents the toner T in the bottle 53 from blocking by rotating.

When a decrease in toner concentration in the developer stored in the developer tank 109 is detected by a sensor (not shown), the toner disposed between the toner tank 108 and the developer tank 109 is refilled based on the toner replenishment signal. The supply roller 113 rotates, and the toner from the toner bottle 53 is transferred to the agent tank 10.
Replenished on 9th. The toner that has fallen from the roller 113 is
The developer is agitated by a rotationally driven developer agitator 56. Further, the developer stream flowing down from the right end of the guide plate 51 is also agitated by the agitator 56, and the friction 11F electric current between the toner and the carrier is promoted.

When the toner T in the toner bottle 53 runs out, hold the handle 57 (FIG. 6) of the bottle, pull it out to the front, and insert a new bottle.

In this example as well, elements other than the magnet 104 in the above-mentioned developing device and the elements supporting it on the copying machine main body 7 constitute the developing unit 18, and the carrier of the developer contained in the developer tank 109 has deteriorated. At this time, the developing unit 18 is pulled out in the direction of arrow C in FIG. 7, and the developing sleeve 3 is removed from the copying machine main body 7 together with the developing unit package 2, as shown in FIG. At this time, the magnet 104 remains supported by the copying machine main body 7.

Next, similarly to the previously described embodiment, the developing sleeve opening 2 of another developing unit 18 containing new developer is opened.
5 and the magnet 104, and push the unit 18 toward the back to set it.

When the developing unit 18 is attached or detached, the slider 20 attached to the developing unit package 2 fits into the guide rail 21 on the copying machine main body 7 side and moves, which is the same as in the case of FIGS. 1 to 4. .

Similar to the leveling member 15 shown in FIG. 2, gears are attached to the back side of the stirring roller 46, toner supply roller 113, conveyance screw 52, and agitator 54, 56, and gears are attached to the rear side of the stirring roller 46, toner supply roller 113, conveyance screw 52, and agitator 54. As these gears are set, these gears mesh with the mating gears on the main body 7 side and are driven to rotate.

At this time, the terminal for the toner concentration detection sensor and the terminal for the remaining toner amount detection sensor in the toner bottle 53 come into contact with the terminals on the copying machine main body side, respectively.

Further, when the developing unit 18 is attached or detached, the doctor blade 11 is applied to the circumferential surface of the developing sleeve 3 to prevent the developer from spilling from the opening 5 of the developing unit package 2.
The developer on the developing sleeve 3 exposed through the opening 5 is removed or the opening 5 is closed with a shutter, which is the same as in the previous embodiment. Immediately before setting a new developing unit 18, the developer is removed. When supplying the agent to the tank 109, the cover 59 on the upper wall of the tank is opened and the supply operation is performed.

As mentioned above, the developing device shown in FIGS. 5 to 7 can also use the magnet 104 many times, so
Similar to the developing device disclosed in Japanese Patent No. 9-164577, the economic burden on the user can be reduced, and the developing unit 18 can be easily attached and detached.

By the way, in this type of developing device using a two-component developer, in order to improve the quality of the developed visible image, it is necessary to sufficiently stir the developer to enhance the triboelectric charging effect on toner particles and carrier. For this purpose, the embodiment shown in FIGS. 5 to 7 is provided with agent stirring means consisting of a stirring roller 46, a conveyance screw 52, and a developer agitator 56.
This stirs the developer. On the other hand, JP-A-59
The developing device disclosed in Japanese Patent Publication No. 164577 also has a magnetic stirring roller provided outside the developing unit package to stir the developer inside the developing unit package. If it is provided outside the unit package, its stirring effect will be reduced.

However, in the configuration shown in FIGS. 5 to 7, the stirring roller 46, the conveyance screw 52, and the developing agitator 56, which constitute the above-mentioned agent stirring means, are disposed inside the developing unit package 2, and the developer is This provides direct stirring action. Therefore, the effect of stirring the developer can be significantly enhanced.

Note that the leveling member 15 shown in FIG. 1 also serves to stir the two-component developer mixture and promote charging of the toner particles and carrier, and is an example of a developer stirring means. However, also in the example shown in FIG. 1, this agent stirring means is disposed within the developing unit package 2, and directly gives a stirring action to the developer. In this way, the configuration shown in FIG. 1 also represents an embodiment corresponding to claim 3.

In FIGS. 5 to 7, the developing sleeve 3 is rotatable with respect to the developing unit package 2, and the magnet 104 supported by the copying machine body is fixed immovably. It goes without saying that the present invention can also be applied to a developing device in which the sleeve 3 is integrally formed with the developing unit package 2 and a magnet supported by the copying machine body is driven to rotate.

By the way, when the above-described developing unit 18 is removed from the copying machine main body 7, the magnets 4, 104 are supported in a cantilevered manner by the copying machine main body via the shaft 22 or the support 48. These magnets 4 and 104 may be supported directly on the copying machine main body 7 in a cantilevered manner, but in any case, since the magnets 4 and 104 are supported in a cantilevered manner, the magnets 4 and 104 are supported by their own weight or magnetic force. There is a risk of elastic bending deformation. With this deformation, when setting the developing unit 18, the developing sleeve 3 is attached to the magnets 4, 10.
4 becomes difficult to insert. This problem is particularly likely to occur if a plurality of magnets are provided adjacent to the main body of the copying machine.

FIGS. 8 to 10 show embodiments corresponding to the configurations according to claims 4 and 5, in which the above-mentioned drawbacks are eliminated.

The basic difference between the developing device shown here and the developing devices shown in FIGS. 5 to 7 is that, as is clear from FIG. 9, there is another developing sleeve 3a below the developing sleeve 3.
is disposed, and this developing sleeve 3a is also
In exactly the same way, the sleeve 3a is rotatably supported by the developing unit package 2 via bearings 40a and 41a, and a magnet 104a is also inserted into the sleeve 3a, and its support 48a and the support 48 of the magnet 104 are connected to a common support plate. 61 is fixed to the support frame 23 of the copying machine main body 7, and the distal end side of the support body 48a is supported by the bearing member 50a of the developing sleeve 3a, and the gear 42 formed on both the developing sleeves 3, 3a , 42a are drivingly connected via a conductive intermediate gear 62 rotatably supported by the developing unit package 2, and are connected to the lower conductive developing sleeve 3a via the conductive gear 42 and the intermediate gear 62.
The point where the voltage from the bias power supply 60 is applied and the magnet holder 6 that supports both magnets 104, 104a.
3 is attached.

In addition, there is another stirring device 64 (
Fig. 8) has been added, but such a stirring device 1i64
This device 64 merely serves to further improve the stirring efficiency of the developer, and this device 64 may be omitted. The stirring device 64 is constructed similarly to the leveling member 15 shown in FIG. Moreover, each magnet 104, 104a is
Although it is formed in a cylindrical shape like the magnet 4 shown in the figure, this may also be a magnet in the form shown in FIG. A seal brush 55a installed in the developing unit package 2 is also in contact with the lower developing sleeve 3a. Since the other configurations are the same as those shown in FIGS. 5 to 7, the same reference numerals are given and explanations for the same parts will be omitted.

During the developing operation, the two-component developer pumped up by the stirring roller 46 is first supplied to the lower developing sleeve 3a that rotates counterclockwise, and then
From there, the receiver is passed to the upper developing sleeve 3, which also rotates counterclockwise, as shown by arrow
1, and the latent image is visualized. By providing a plurality of developing sleeves 3, 3a in this way, it is possible to increase the developing efficiency and improve the quality of the visible image.

When replacing the developing unit 18, as in the previous embodiment,
While sliding the slider 20 fixed to the developing unit package 2 on the guide rail 21 on the copying machine main body side, the developing unit package 2 is moved onto the developing sleeves 3, 3a.
At the same time, the developing unit 18 is pulled out in the direction of arrow C in FIG. 9, and the developing unit 18 is removed from the copying machine main body 7 as shown in FIG. 1o.

At this time, the upper and lower two magnets 104, 104a left on the copying machine main body 7 are supported by the main body 7 in a cantilever shape, but if only this support is used, the magnets 104, 1
04 a is elastically bent and deformed by its own weight or magnetic force.

In particular, multiple magnets 104.104 as shown in FIG.
If they are located adjacent to each other, they may attract or repel each other with their magnetic force, and their bending deformation may become significant. Furthermore, when a plurality of developing sleeves are used, the developing capacity increases, so the diameter of each developing sleeve 3, 3a can be made thinner, for example, 30 cm or less, and accordingly, the diameter of each magnet 104, 104a can also be reduced. Become thinner. However, in order to be able to copy large-sized originals, developing sleeves 3, 3a and magnets 104, 104 are required.
As for the length of a, it cannot be shortened and becomes 1
For example, in order to obtain A3 size copy paper, it is necessary to set the length of the magnets 104, 104a to 420 mm or more. When magnets 104, 104a having such a long length and small diameter are used, they are particularly susceptible to bending deformation. In this way, the magnet 104,
If 104a is deformed, the work efficiency when setting a new developing unit package in the copying machine main body 7 will be reduced as described above.

Therefore, in this example, the magnetic holder 63 briefly shown above is used.
is provided. This holder 63 is.

As shown in Figures 9 and 10, the upper and lower magnets 1
04.104a has portions 65, 65a which are slidable relative to each magnet 104° 104a and supports 48, 48a.

The lower end of the magnet holder 63 is fixed to the carriage 66, and a roller 67 provided on the lower surface of the carriage 66 is movably supported on a guide rail 68 extending in the direction of pulling out or pushing in the developing unit package 2. has been done.

Further, an elastically bendable arm 69 is protruded from the magnet holder 63, and a claw 70 is formed at the tip of the arm 69.

When the developing unit package 2 and the developing sleeve 33a are set in the copying machine main body 7 as shown in FIG. 9, the pawl 70 is engaged with a notch 71 formed in the developing unit package 2. . Therefore, when the developing unit package 2 starts to be pulled out in the direction of arrow C, the magnet holder 63 is also pulled out together with the developing unit package 2. At this time, the magnet holder 63 has its numbered portion 65.65a sliding against each support 48.48a and each magnet 104, 104a, and the roller 6
7 rolls on the guide rail 68 while being guided by the guide rail 68.

When the magnet holder 63 moves to the position shown by the chain line in FIG.
The magnet holder 63 stops when it comes into contact with a stopper 72 on the near side that is protruding from the front side. If the developing unit package 2 is further pulled in the direction of arrow C in this state, the tip of the arm 69 will be elastically deformed in a downward direction, and the claw 70 will open into the notch 71.
The developing unit package 2, that is, the developing unit 18 can be removed from the copying machine main body 7 without any trouble.

At this time, the magnet holder 63 is left in the position shown by the chain line in FIG. I will support it. This prevents bending deformation of each magnet 104, 104a, and maintains a mutually parallel posture.

Therefore, when installing the developing unit package 2, each magnet 104, 104a is securely attached to each developing sleeve 3.
, 3a, and can easily set the developing unit package 2. At this time, in order to push in the developing unit package 2, press the rear part 73 of the claw 70 of the arm 69 (
(on the right side in Fig. 9), and place it on the developing unit package 2.
ζ, magnet holder 63 and carriage 66
is also pushed to the back side by the rolling of the roller 67. Then, when the carriage 66 hits the stopper 74 on the back side protruding from the guide rail 68 and stops, when the developing unit package 2 is further pushed into the back side, the tip of the arm 69 is bent downward and deformed, and the developing unit package The rear part 73 of 2 gets over the claw 70, and the claw 70 passes through the notch 7.
1, and the developing unit package 2 is set in the final mounting position shown in FIG.

As described above, since the magnet holder 63 is supported so as to be movable in the mounting/detaching direction of the developing unit package 2 when the developing unit package 2 is mounted/detached, the magnet holder 63 does not interfere with the operation of the developing unit package 2 in any way. Moreover, since the magnet holder 63 supports the magnets 104 and 104a even when the developing unit package 2 is set in the copying machine main body 7, the strength of supporting these magnets can be increased. Furthermore, since the magnet holder 63 operates in conjunction with the attachment/detachment operation of the developing unit package 2, the operator does not need to operate the magnet holder 63 at all.

By the way, as shown in FIG. 10, when the developing unit package 2, that is, the developing unit 1 is removed, the magnets 104, 104a are removed from the developing sleeves 3, 3a and left in the copying machine main body 7 in a naked state. . Therefore, the developer and other developers tend to adhere to the magnets 104 and 104a by magnetic force. In particular, if the guide rail 68 is provided below the magnet 104a as shown in FIG.
There is a strong possibility that they will be attracted to and adhere to 04, 104a.

Therefore, in the embodiment shown in FIG. 11, a cover 76 is added to the structure of the embodiment shown in FIGS. 9 and 10, thereby preventing the above-mentioned problems. One end of the cover 76 is fixed to the magnetic holder 63, and the other end is fixed to the copying machine main body 7, in the example shown, the support plate 61, and is expandable and retractable in the direction of attaching and detaching the developing unit package 2. It is composed of bellows. Further, in the example of FIG. 11, the receiver of the magnet holder 63 is
However, it is not semicircular as shown in FIG. 10 but circular, and seals the inside of the cover 76.

As mentioned above, insert the developing unit package 2 into the copying machine main body 7.
When the magnet holder is separated from the magnet holder and reaches the position shown by the chain line in FIG. 9, the cover 76 opens as shown in FIG. 11, covering the upper, lower, left, and right sides of the magnets 104, 104a. That is, the magnets 104 and 104a are surrounded by the cover 76, the magnet holder 63, and the support plate 61 from all sides. This prevents developer and the like from adhering to the magnets 104, 104a due to magnetic force.

This prevents the magnets 104, 104a from getting dirty, and when the developing operation starts, the magnet 1
It is also possible to prevent troubles such as abnormal noises caused by foreign matter adhering to the parts 04 and 104a.

Further, it is possible to prevent a problem in which a tool or the like is directly hit against the magnets 104, 10a, causing damage thereto.

In order to set the developing unit package 2, push it in the direction opposite to the arrow C and push the magnetic holder 63 in as described above, and the expandable cover 76 will be folded and contracted, allowing the developing unit package 2 to be set. When finished.

The cover 76 is housed in the space between the support plate 61 and the magnet holder 63 (FIG. 9), and the cover 76 does not interfere with other elements. In this way, the cover 76 expands and contracts in conjunction with the attachment/detachment operation of the developing unit package 2, so the operator does not need to operate the cover 76 at all.

In the example shown in FIG. 11, the cover 76 covers all sides of the magnets 104, 104a, but this is intended to prevent, for example, the developer on the guide rail 68 from adhering to the magnets 104, 104a.

A cover that covers only the lower region of the magnets 104, 104a may be used; in short, a telescopic cover that covers at least a portion of the magnet may be used.

The above-described configurations shown in FIGS. 8 to 11 are embodiments corresponding to claims 4 to 6, but in the configurations described in these claims, the developer contained in the developing unit package 2 is This is applicable not only when the developer is a component-based developer, but also when it is a component-based developer. Furthermore, if only one magnet is provided instead of multiple magnets, the developing sleeve is integrated into the developing unit package. It can also be applied to cases where the magnet is rotationally driven.

〔Effect of the invention〕

Since the present invention is configured as described above, it exhibits the following excellent effects.

According to the developing device according to the first aspect, in addition to the advantage that the magnet can be reused, the structure of the developing unit package can be simplified and its cost can be reduced.

According to the developing device according to claim 2, in addition to the above effects,
The amount of developer in the developer tank can be reduced, and the structure of the developing unit package can be downsized.

According to the developing device according to the third aspect, the effect of stirring the developer in the developing unit package can be enhanced.

According to the developing device according to the fourth aspect, when the developing unit package is detached from the main body of the image forming apparatus, the supporting stability of the magnet is increased and the magnet is prevented from being bent, and the developing unit package is easily set. Operability can be improved.

According to the developing device according to the fifth aspect, the magnetic holder does not become an obstacle at all when the developing unit package is attached or detached.

According to the developing device according to the sixth aspect, it is possible to prevent developer and other foreign substances from adhering to the magnet.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing an example of a developing device according to the present invention;
Figure 2 is a longitudinal sectional view of the machine, with the developer omitted, Figure 3 is an enlarged view showing the electrodes provided on the developing sleeve, and Figure 4 is a perspective view of the developing unit package when removed from the copying machine body. 5 is a cross-sectional view showing another embodiment, FIG. 6 is a perspective view when the developing unit package is removed from the copying machine main body, with the solenoid omitted, and FIG. 7 is a cross-sectional view showing another embodiment. FIG. 8 is a cross-sectional view of another embodiment, and FIG. 9 is a longitudinal cross-sectional view of the developing device shown in the figure, with the developer omitted. FIG. 10 is a perspective view of the developing unit package shown in FIG. 8 when removed from the copying machine main body, with the solenoid omitted, and FIG. 11 is a diagram showing another embodiment. FIG. 1...Developing device 2...Developing unit package 3.3a...Developing sleeve

Claims (6)

[Claims] (1) Detachably supported by the main body of the image forming apparatus;
A developing unit package that houses a developer therein, and a developing sleeve that is provided in the developing unit package and that carries a developer that is used to visualize an electrostatic latent image formed on a latent image carrier. and a magnet that is inserted into the developing sleeve when the developing unit package is set in the image forming apparatus main body and is supported on the image forming apparatus main body side, and the developing unit package is mounted on the image forming apparatus main body side. In the developing device, when the developing sleeve is removed from the image forming apparatus main body together with the developing unit package, and the magnet remains supported by the image forming apparatus main body, the magnet is moved by a drive device. A developing device, characterized in that the developing sleeve is rotatably supported by an image forming apparatus main body so as to be rotationally driven, and the developing sleeve is integrally formed with a developing unit package. (2) The inside of the developing unit package is partitioned into a toner tank containing toner and a developer tank containing a two-component developer made of toner and carrier, and the developing sleeve is located on the developer tank side. The toner in the toner tank is supplied to the two-component developer on the developing sleeve via a toner supply roller supported by the developing unit package, and the toner supplied from the toner tank is stored in the toner tank. 2. The toner according to claim 1, wherein the toner is frictionally charged by a frictional member that presses against the toner on the replenishment roller, and a leveling member is disposed in the developer tank to correct uneven distribution of the two-component developer stored therein. Developing device. (3) removably supported by the main body of the image forming apparatus;
A developing unit package that contains a two-component developer therein, and a developer that is provided in the developing unit package and is used to visualize the electrostatic latent image formed on the latent image carrier. a developing sleeve that is inserted into the developing sleeve when the developing unit package is set in the image forming apparatus main body and supported by the image forming apparatus main body; a two-component developer agitating means, and when the developing unit package is removed from the image forming apparatus main body, the developing sleeve is removed from the image forming apparatus main body together with the developing unit package, and the magnet is removed from the image forming apparatus main body. A developing device that is left supported on a forming device main body side, wherein the agent stirring means is installed inside a developing unit package. (4) removably supported by the image forming apparatus main body;
A developing unit package that houses a developer therein, and a developing sleeve that is provided in the developing unit package and that carries a developer that is used to visualize an electrostatic latent image formed on a latent image carrier. and a magnet that is inserted into the developing sleeve when the developing unit package is set in the image forming apparatus main body and is supported on the image forming apparatus main body side, and the developing unit package is mounted on the image forming apparatus main body side. When detached from the image forming apparatus main body, the developing sleeve is removed from the image forming apparatus main body together with the developing unit package, and the magnet remains supported on the image forming apparatus main body side. A magnet holder is provided which is supported in a cantilever shape on the main body and supports a magnet portion other than the supporting portion of the magnet when the developing unit package is removed from the image forming apparatus main body. Developing device. (5) The developing device according to claim 4, wherein the magnetic holder is supported so as to be movable in the mounting/detaching direction of the developing unit package when the developing unit package is mounted/detached. (6) One end of the magnet is fixed to the magnetic holder and the other end is fixed to the image forming apparatus main body, and when the developing unit package is removed from the image forming apparatus main body, the magnet remains on the image forming apparatus main body. 6. The developing device according to claim 5, further comprising a stretchable cover that covers at least a portion of the developing device.