JPH07230209A - Image forming device and developer supplying method - Google Patents

Abstract

PURPOSE:To use again recovered developer well mixed with fresh developer at a fixed mixing ratio by supplying the recovered developer and fresh developer to a mixing chamber and stirring and mixing both developers. CONSTITUTION:The recovered developer stored in a recovering chamber 13 and the fresh developer in a replenishment chamber 14 are attracted to the surface of magnet rollers 15 and 16, respectively, to coat the surfaces with them. When the magnet rollers 15 and 16 normally rotate, the recovered developer and fresh developer are supplied to the mixing chamber 17, and attracted onto a magnet roller 18. At this time, the mixing ratio between the recovered developer and fresh developer is controlled according to a ratio between the rotating speeds of the magnet rollers 15 and 16. When supplying the developer to a developing chamber 5e, the magnet roller 18 is first rotated reversely for a prescribed time, and the developer is separated from the surface of the magnet roller 18 due to a gap D3 and accumulate in a staying part 17a. The accumulated developer starts to circulate in the staying part 17a, and both developers are sufficiently stirred and mixed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus and a developer supplying method which utilize a developer removed from an image bearing member after image formation.

[0002]

2. Description of the Related Art In an image forming apparatus such as a copying machine, a latent image is formed by selectively exposing an image carrier uniformly charged by a charger to form a latent image by a developing device. At the same time as visualizing, the image formed by the developer is transferred to a recording medium to record an image.

In such an apparatus, the developer remaining on the image carrier after the development image is transferred is removed by the cleaning means. The removed developer has been conventionally discarded as a waste developer, but in recent years, it has been considered to reuse the waste developer for the purpose of resource saving and energy saving.

As a constitution for reusing such a collected developer, for example, after removing contaminants through a regenerating device such as a filter, the collected developer is collected in a developing device, and mixed with a new developer to be re-developed. Alternatively, after collecting in the developer hopper that supplies the new developer to the developing device and mixing with the new developer,
Replenish to the developing device and use again for development.

However, in the above-mentioned conventional example, the recovered developer is directly returned to the developing device or the hopper to be mixed with the new developer, and the mixing ratio of the new developer and the recovered developer is controlled,
Also, the mixing and stirring of the new developer and the recovered developer is not sufficient.

Therefore, the recovered developer may be partially replenished to the developing device in a state where the mixing ratio is high, and in this case, the chargeability of the developer becomes insufficient, which may cause inconvenience in the developing process. .

In order to solve this problem, a replenishment chamber for the new developer and a replenishment chamber for the reclaimed developer are provided, and the replenished developer is replenished so as to be uniform in the width direction near the outlet of the new developer. A proposal has been made to do so. For example, a structure in which the height is gradually reduced from one end in the width direction to the other end by the action of the spiral member so as to be supplied over the upper surface at one end of the wall surface, or the opening located at one end in the width direction big,
A configuration has been proposed in which a spiral member is arranged in a hollow cylindrical member having a plurality of openings that are smaller toward the opening located at the other end in the width direction.

[0008]

However, in the above construction, the uniformity of the replenishment of the developer in the width direction is influenced by the amount of the developer per unit cross-sectional area conveyed by the spiral member.

Further, after the collected developer is replenished to the vicinity of the discharge port, it is difficult to improve the mixing property of the new developer and the collected developer because the stirring is not actively performed.

The present invention is to solve the above-mentioned problems of the prior art, and an object of the present invention is to reuse a recovered developer with a novel developer in a sufficiently mixed state at a constant mixing ratio. It is an object of the present invention to provide a possible image forming apparatus and a developer supply method.

[0011]

A typical constitution according to the present invention for achieving the above object is to collect a developer after image formation in an image forming apparatus for forming an image using the developer. Means, a recovery chamber for storing the recovered developer, a replenishment chamber for storing a new developer, and a recovery developer discharge port in the recovery chamber, which is normally rotated to supply the recovered developer. A first magnet roller, a second magnet roller arranged in the replenishment chamber at the new developer discharge port and rotated forward to supply the new developer, and a recovered developer and replenishment supplied from the recovery chamber. The image forming apparatus is characterized in that a mixing chamber for accommodating a new developer supplied from the chamber and a stirring means for stirring the developer in the mixing chamber are provided.

As another configuration, the gap between the magnet roller and the inner wall of the chamber facing the upstream side in the reverse rotation direction of the magnet roller is smaller than the gap between the inner wall and the magnet roller facing the downstream side in the reverse rotation direction. It is characterized by making it narrower.

[0013]

In the above construction, the collected developer and the new developer are supplied to the mixing chamber by the rotation of the first and second magnet rollers, and both the developers are agitated by the agitating means to be sufficiently mixed. . An image is formed using this developer.

Further, the gap between the inner wall of the chamber facing the upstream side in the reverse rotation direction of the magnet roller and the magnet roller is made narrower than the gap between the inner wall facing the downstream side in the reverse rotation direction and the magnet roller. By rotating the roller in the reverse direction, the developer can be uniformly attached to the surface of the roller, and the mixing ratio can be made constant.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The structures of an image forming apparatus and a developer supplying method according to an embodiment of the present invention will be specifically described with reference to the drawings.

[First Embodiment] FIGS. 1 to 5 show a copying machine which is an image forming apparatus according to the first embodiment. FIG. 1 is an explanatory view of the entire structure of the copying machine, and FIGS. FIG. 3 is an explanatory diagram of a developer supply configuration.

Here, as the order of the description, the entire structure of the copying machine will be described first, and then the structures of the developer supply device and the developer supply method will be described.

[Overall Structure of Image Forming Apparatus] First, copying machine A
The overall configuration of will be described with reference to FIG. In FIG.
Reference numeral 1 denotes a document reading means, which illuminates a document placed on the platen glass 1a with an illumination lamp 1b, scans the lamp 1b and a reflecting mirror 1c1 for scanning, and reflects light from the document on the mirror 1c1. And reflection mirrors 1c2, 1c3, 1
It irradiates the photosensitive drum 2, which is an image carrier, via c4, 1c5, 1c6, and the lens 1d having the focusing and zooming functions to form an electrostatic latent image.

The photosensitive drum 2 has a photosensitive layer on its surface and can be rotated in the direction of the arrow in FIG. 1 by the main motor 3 in accordance with the image forming operation. Around the photosensitive drum 2, a charging unit 4, a developing unit 5, a transfer unit 6 and a cleaning unit 7 for uniformly charging the surface of the photosensitive drum are arranged. The surface of the rotating photosensitive drum 2 is uniformly charged by the charging means 4, and an electrostatic latent image is formed by the exposure from the document reading means 1, and the developing means 5 magnetically develops the electrostatic latent image. The agent is transferred to form a developed image. The developing means 5 sends the developer in the developer hopper 5a to a developing sleeve 5c containing a fixed magnet by a feeding member 5b, rotates the developing sleeve 5c, and imparts a triboelectric charge by the developing blade 5d. A layer is formed on the surface of the developing sleeve 5c, and the developer is transferred to the photosensitive drum 2 according to the latent image to form a developed image and visualize it.

Then, the developed image is transferred to the recording medium 9 conveyed by the conveying means 8 by applying a voltage from the transfer means 6.
The transfer means 6 has a transfer charger 6a and a separation charger 6b. The transfer charger 6a applies a voltage having a polarity opposite to that of the developing toner to transfer the developed image to the recording medium 9 conveyed, A voltage is applied to the recording medium 9 after the image transfer by the separation charger 6b to separate the recording medium 9 from the photoconductor drum 2.

The developer remaining on the surface of the photosensitive drum 2 after transferring the developed image onto the recording medium 9 is removed by the cleaning means 7 which scrapes off with the cleaning blade 7a and collects in the collected developer reservoir 7b. The developer and the foreign matter are separated by the reproducing means and sent to the developer hopper 5a.

On the other hand, in the constitution of the conveying means 8, upper and lower cassettes 8a1 and 8a2 are mounted below the main body of the apparatus, and recording media 9 stored in the respective cassettes 8a1 and 8a2 are picked up one by one by pickup rollers 8b1 and 8b2. It can be supplied to the pair of registration rollers 8c. The cassette 8a1, 8
The recording medium 9 supplied from b2 or the manual feed tray 8d is
The registration roller pair 8c is driven and conveyed in synchronization with the image forming operation by the photosensitive drum 2, and the developed image is transferred at the position of the transfer unit 6 as described above. Then, the recording medium 9 after the image transfer is driven by the driving belt 10a by the conveyor belt 8e.
Then, the transfer image is conveyed to a fixing means 10 including a heating and pressing roller 10b having a built-in heater, heat and pressure are applied by the fixing means 10 to fix the transferred image, and the transfer image is discharged to a discharge tray 8g by a discharge roller pair 8f. The image forming apparatus has a re-conveying guide portion 8h for conveying the recording medium 9 once image-formed to the image transfer position again, an intermediate tray 8i, and a re-conveying portion 8j.

Further, in the copying machine A according to this embodiment, the automatic document feeder 11 is mounted on the upper part of the original glass 1a so that a plurality of originals can be automatically separated and fed.
Since the structure of the automatic document feeder 11 is publicly known, a detailed description thereof will be omitted.

{Developer Supply Device and Developer Supply Method} In the copying machine A according to this embodiment, the developer collected by the cleaning means 7 is supplied to the developer hopper 5a of the developing means 5 by the conveying pipe 12. The developer supplying device B mixes with a new developer at a constant ratio for reuse.

The recovered developer is supplied to the developer hopper 5a after removing contaminants such as paper dust by a developer regenerating means (not shown). As the constitution of the developer regenerating means, for example, a vibrating non-magnetic mesh is horizontally arranged, and rotatable magnet rollers are arranged above and below the mesh. Then, the developer collected by the cleaning means 7 is supplied by the magnet roller on the lower side of the mesh, and the collected developer is magnetically attracted by the magnet roller on the upper side. As a result, when the recovered developer passes through the mesh, contaminants such as paper dust are removed, and the non-magnetic foreign matter is removed by gravity.

The developer according to the present invention contains an external additive (for example, strontium titanate) in a toner in a constant weight ratio. Since the external additive and the toner have opposite polarities, the toner is transferred to the recording medium 9 by the voltage application by the transfer charger 6a, but the external additive is hardly transferred.
Therefore, the content ratio of the external additive in the recovered developer is higher than that of the new developer. If the recovered developer and the new developer are mixed at the same ratio, the ratio of the external additive during development becomes higher than the proper level, and the fog level of the image becomes high. Therefore, in this embodiment, the developer supply device B
By this, the collected developer is mixed with the new developer in a fixed ratio, and the weight ratio of the external additive to the toner is supplied to the developing means 5 in a predetermined range.

Next, the structure of the developer supplying device B will be described with reference to FIGS. Incidentally, FIG. 2 (a)
3A and 3B are explanatory views for driving the magnet roller, and FIGS. 5A and 5B are magnet roller at the time of supplying the developer. It is a drive explanatory view.

As shown in FIG. 2A, the developer hopper 5a is provided with a recovery chamber 13 for storing the recovered developer and a replenishment chamber 14 for storing the new developer. A first magnet roller 15 is provided at the developer discharge port,
The second magnet roller 16 is provided in the developer discharge port of the replenishing chamber 14.
Is provided. Each magnet roller 15, 16
It is a cylindrical roller in which N poles and S poles are alternately arranged in the circumferential direction. As shown in FIG. 3, gears 15b and 16b attached to rotary shafts 15a and 16a are drive motors 15c and 16c, respectively.
It is attached so as to rotate forward and backward by meshing with the pinion gear of.

Since the developer has magnetism, when the magnet rollers 15 and 16 rotate, the developer is adsorbed on the surface of the developer and supplied from the discharge port to the mixing chamber 17 located below. In this embodiment, the magnet roller
The developer is supplied to the mixing chamber 17 when the members 15 and 16 rotate forward as shown by the arrow in FIG.

The magnet rollers 15 and 16 and each chamber
The relationship between the wall surfaces of 13 and 14 is that the gap D ₁ between the inner walls of the recovery chamber 13 and the replenishment chamber 14 and the magnet rollers 15 and 16 where the magnet rollers 15 and 16 face each other on the upstream side in the reverse rotation direction is downstream in the reverse rotation direction. It is set to be narrower than the gap D ₂ between the inner walls facing each other and the magnet rollers 15 and 16 (D ₁ <D ₂ ).

In the replenishing chamber 14, there is provided a rotatable stirring member 16d for feeding the new developer to the magnet roller 16.

A third magnet roller 18 is also provided at the developer discharge port of the mixing chamber 17. This magnet roller
Reference numeral 18 constitutes a stirring means as described later, which is a cylindrical roller in which N poles and S poles are alternately arranged in the circumferential direction, like the magnet rollers 15 and 16 described above. As shown in FIG. 4, the gear 18b attached to the rotary shaft 18a meshes with the pinion gear of the drive motor 18c and is attached so as to be rotatable in the forward and reverse directions.

When the magnet roller 18 is rotated, the surface of the magnet roller 18 is attracted and coated with a developer, which is supplied from the discharge port to the developing chamber 5e located below, and is fed to the developing sleeve 5c by the feeding member 5b. The magnet roller 18 also supplies the developer to the developing chamber 5e when rotated in the direction (forward rotation) shown by the arrow in FIG.

The magnet roller 18 and the mixing chamber 17
The relationship between the inner wall of the mixing chamber 17 where the magnet roller 18 faces the upstream side in the reverse rotation direction and the gap D ₃ between the magnet roller 18 and the inner wall where the magnet roller 18 faces the downstream side in the reverse rotation direction similarly to the above. Is set to be smaller than the gap D ₄ between the magnet roller 18 and the magnet roller 18 (D ₃ <D ₄ ).

A sensor 5f for detecting the remaining amount of the developer is provided in the developing chamber 5e.

Next, a method for mixing and agitating the recovered developer and the new developer at a constant mixing ratio and supplying them to the developing chamber 5e will be described.

As described above, the recovered developer stored in the recovery chamber 13 and the new developer in the replenishment chamber 14 are magnetically coated on the surfaces of the magnet rollers 15 and 16 by adsorption. When the amount of the developer in the recovery chamber 13 and the supply chamber 14 is large, the developer is coated over the entire width direction (rotation axis direction) of the magnet rollers 15 and 16. However, when the amount of the developer is small, the developer may be unevenly distributed and coated on a part of the magnet rollers 15 and 16.

If the developer is replenished in the unevenly distributed coating state, it is replenished in a non-uniform amount in the width direction of the magnet rollers 15 and 16, and the collected developer and the new developer are mixed at a constant mixing ratio. Mixing and stirring properties deteriorate.

Therefore, in this embodiment, as shown in FIG. 5A, first, the magnet rollers 15 and 16 are reversely rotated in the arrow direction. Then, the magnet rollers 15 and 16 and the minute distance D
The developer on the roller surface is scraped off by the protrusion 19a having a value of ₁ , and the developer is collected in this portion. When it is further rotated in the reverse direction, the excess developer is attracted by the magnetic force of the portion not coated with the developer, and the magnet roller
Coated on 15 and 16. When the reverse rotation operation is continued for a predetermined time, the developer is uniformly coated on the surfaces of the magnet rollers 15 and 16 in the width direction.

Next, as shown in FIG. 5B, a magnet
Rollers 15 and 16 are rotated forward to collect recovered developer and new
The developer and the mixing chamber 17 are supplied. At this time, the collection room 13 and
And a gap between the magnet rollers 15 and 16 at the outlet of the supply chamber 14.
D₂Is formed on the magnet rollers 15 and 16 and
Image agent is D₂Coated with a thickness of. Furthermore
When the gnet rollers 15 and 16 rotate forward, the magnet roll
La 15, 16 and minute gap D ₁The protrusion 19b with
The image agent is scraped off and supplied to the mixing chamber 17.

In this embodiment, the thickness of the developer layer coated on the magnet rollers 15 and 16 is set to the same D ₁ , and the number of teeth of the drive gears 15b and 16b is also set to the same value. The mixing ratio of the developer and the new developer is 15
It is controlled by the rotation speed ratio of c and 16c. For example, when the mixture ratio is collected developer: new developer = 1: 9, the rotation speed ratio of the drive motors 15c and 16c may be set to 1: 9.

As described above, the recovered developer and the new developer, which are uniform in the width direction and are supplied in the predetermined mixing ratio, are mixed in the mixing chamber.
It is attracted onto the magnet roller 18 of 17 by magnetic force.
At this time, as shown in FIG.
When the developer is supplied, the developer 18 first rotates in the reverse direction for a predetermined time, and the developer is separated from the magnet roller 18 by the gap D ₃ and stored in the retaining portion 17a. At this time, since the developer is peeled off one after another, the accumulated developer is accumulated in the accumulation portion 17
Reflux occurs at a and the developers are sufficiently stirred and mixed.

Next, the magnet roller 18 is rotated in the opposite direction to the above to supply the mixed developer to the developing chamber 5e. At this time, a magnet roller is installed at the outlet of the mixing chamber 17.
18 and a gap D ₄ are formed, and the developer on the magnet roller 18 is coated to a thickness D ₄ . Further the magnet roller 18 rotates in the forward direction, is supplied scraped developer to the developing chamber 5e by the projecting portion 19c having a magnet roller 18 with a small gap D _3. As previously mentioned,
Before supplying the developer by rotating the magnet rollers 15, 16 and 18 in the forward direction, the developer is uniformly coated on the magnet rollers 15 and 16 by rotating the magnet rollers 15 and 16 in a reverse direction for a predetermined time. The recovered developer and the new developer can be sufficiently mixed. Therefore, it is possible to mix the recovered developer and the new developer in an accurate ratio, and since the charging characteristics are not adversely affected, it is possible to reuse the recovered developer without causing image fog. I can.

[Second Embodiment] In the above-described embodiment, the magnet roller 18 is rotated in the reverse direction so that the developer is agitated and mixed in the retaining portion 17a. However, as a second embodiment, as shown in FIG. In addition, the return member 20 may be provided in the retaining portion 17a. In this embodiment, a side wall 17b of the mixing chamber 17 near the retention portion 17a is vertical, and a guide plate 20 as a reflux member is provided near the side wall 17b. The other structure is the same as that of the first embodiment described above.

As a result, the developer peeled off from the magnet roller 18 is pushed by the developer peeled off one after another and ascends upward between the side wall 17b and the guide plate 20, and eventually the guide plate.
It falls to the right side of 20 and adheres again to the magnet roller 18, and when it is further conveyed, it separates from the magnet roller 18 again and recirculates. If this operation is continued, the recovered developer and the new developer will be more sufficiently mixed by the reflux operation.

[Other Embodiments] In the above-described embodiments, the magnet rollers 15 and 16 are rotated in reverse to rotate the magnet rollers.
Although the developer is coated on 15 and 16 and then the developer is supplied by positively rotating the developer, a developer residual amount detection sensor is provided in the replenishment chamber 14 so that the new developer is provided in the replenishment chamber 14. When the amount becomes equal to or less than a predetermined amount, a new developer may be replenished. In this case, since the new developer is sufficiently secured on the magnet roller 16, it is always coated uniformly in the width direction. Therefore, it is not necessary to rotate the magnet roller 16 in the reverse direction, and it is sufficient to rotate the magnet roller 16 in the forward direction when the developer is supplied.

In the embodiment described above, the recovery chamber 13
The motors 15c and 16c independently rotate the magnet rollers 15 and 16 in the replenishing chamber 14 and the reciprocating chamber 14, respectively. When the rotation speed ratio at the time of replenishing the developer is determined, the magnet rollers 15 and 16 are driven. If the gears are set so that they do not have a predetermined rotation speed ratio and are connected, one magnet can rotate the magnet rollers 15 and 16 in the forward and reverse directions. Absent.

Further, in the above-described embodiment, the mixing of the recovered developer and the new developer in the mixing chamber 17 is performed by the magnet roller 18
However, it is not always necessary to use the magnet roller 18 for mixing, and for example, a stirring plate or the like may be rotated to stir and mix the collected developer and the new developer. By doing so, the assembly of the device becomes easy.

Further, in the above-mentioned embodiments, the image bearing member is not limited to the above-mentioned photosensitive drum, but includes, for example, the following. First, a photoconductor is used as the photoconductor, and as the photoconductor, for example, amorphous silicon,
Amorphous selenium, zinc oxide, titanium oxide, organic photoconductor (OPC), etc. are included. The shape on which the photoconductor is mounted includes, for example, a drum-shaped, belt-shaped rotating body, a sheet-shaped body, and the like. Generally, a drum-shaped or belt-shaped one is used. For example, in the case of a drum type photoconductor, a photoconductor is vapor-deposited or coated on a cylinder of aluminum alloy or the like. Is.

In the above-described embodiment, the copying machine in which the image carrier, the developing means, the cleaning means and the like are directly attached to the main body of the apparatus is illustrated, but the image carrier, the developing means, the cleaning means and the like are integrally formed into a cartridge. The present invention can also be applied to an image forming apparatus that is detachable from the apparatus body. By making each of the above means into a cartridge, maintenance can be easily performed.

Further, in the above-mentioned embodiment, the copying machine is exemplified as the image forming apparatus, but the apparatus is not limited to the copying machine as long as it is an apparatus for forming an image by using a developer, and for example, a printer, a facsimile machine or the like. However, the developer supply device and the developer supply method of the present invention can be applied.

[0052]

As described above, the present invention has the first and second aspects.
The collected developer and the new developer are supplied to the mixing chamber by the rotation of the magnet roller, and both the developers are agitated and mixed by the agitating means so that the recovered developer and the new developer are sufficiently supplied. It can be mixed and supplied.

Further, the gap between the inner wall of the chamber facing the upstream side in the reverse rotation direction of the magnet roller and the magnet roller is made narrower than the gap between the inner wall facing the downstream side in the reverse rotation direction and the magnet roller. By rotating the roller in the reverse direction, the developer can be uniformly attached to the surface of the roller, and the developer having a constant mixing ratio and being sufficiently mixed can be supplied.

Further, a third magnet roller is used as the stirring and mixing means, and the gap between the inner wall of the recovery chamber and the third magnet roller, which opposes on the upstream side in the reverse rotation direction of the third magnet roller, is located on the downstream side in the reverse rotation direction. The collected developer and the new developer can be sufficiently mixed and supplied by forming the gap narrower than the gap between the inner wall and the third magnet roller that face each other and rotating the third magnet roller in the reverse direction for a predetermined time. It can be done.

Therefore, the collected developer can be effectively used without any trouble, and the charging performance can be kept constant, and the image can be recorded without fog on the image.

[Brief description of drawings]

FIG. 1 is a diagram illustrating the overall configuration of a copying machine.

FIG. 2A is an explanatory view of a developer supply configuration, and FIG. 2B is an enlarged view of a main part.

FIG. 3 is an explanatory diagram for driving a magnet roller.

FIG. 4 is an explanatory diagram for driving a magnet roller.

FIG. 5 is an explanatory diagram of driving a magnet roller when a developer is supplied.

FIG. 6 is an explanatory diagram of a developer supply configuration according to a second embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Original reading means, 1a ... Original platen glass, 1b ... Illumination lamp, 1c1-1c6 ... Reflective mirror, 1d ... Lens, 2 ... Image carrier, 3 ... Main motor, 4 ... Charging means, 5 ... Developing means, 5a ... developer hopper, 5b ... feeding member, 5c developing sleeve, 5d ... developing blade, 5e ... developing chamber, 5f ...
Remaining amount detection sensor, 6 ... Transfer means, 6a ... Transfer charger, 6
b ... Separation charger, 7 ... Cleaning means, 7a ... Cleaning blade, 7b ... Collected developer reservoir, 8 ... Conveying means, 8a1, 8a2 ... Cassette, 8b1, 8b2 ... Pickup roller, 8c ... Registration roller, 8d ... Manual feed tray ,
8e ... Conveying belt, 8f ... Ejecting roller, 8g ... Ejecting tray, 8h ... Reconveying guiding section, 8i ... Intermediate tray, 8j ... Reconveying section, 9 ... Recording medium, 10 ... Fixing means, 10a ... Driving roller, 10b ... Heat pressing roller, 11 ... Automatic document feeder, 12
... conveyance pipe, 13 ... collection chamber, 14 ... replenishment chamber, 15,16 ... magnet roller, 15a, 16a ... rotating shaft, 15b, 16b ... gear, 15c, 16c ... motor, 16d ... stirring member, 17 ... mixing chamber, 17a ... Retaining portion, 17b ... Side wall, 18 ... Magnet roller, 18a ... Rotating shaft, 18b ... Gear, 18c ... Motor, 19a,
19b, 19c ... protrusion, 20 ... guide plate

Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI Technical display location G03G 15/09 Z 21/10

Claims (11)

[Claims] 1. An image forming apparatus for forming an image using a developer, a means for collecting the developer after image formation, a collecting chamber for storing the collected developer, and a replenishment for storing a new developer. A chamber, a first magnet roller disposed in the recovery chamber in the recovery developer outlet, and rotating forward to supply the recovered developer, and a first magnet roller disposed in the replenishment chamber in the new developer outlet, A second magnet roller that rotates forward to supply the new developer, a mixing chamber that stores the collected developer supplied from the collection chamber and the new developer supplied from the replenishment chamber, and a developer in the mixing chamber. An image forming apparatus comprising: a stirring unit configured to stir the. 2. At least the first magnet roller is configured so as to be rotatable in the forward and reverse directions.
The image forming apparatus described. 3. The image forming apparatus according to claim 1, wherein the first magnet roller and the second magnet roller are both configured to be rotatable in forward and reverse directions. 4. The first magnet roller has a gap between the first magnet roller and the inner wall of the recovery chamber facing each other on the upstream side in the reverse rotation direction, and a gap between the first inner wall and the inner wall facing each other on the downstream side in the reverse rotation direction.
The second magnet roller is narrower than the gap between the magnet roller and the inner wall of the replenishing chamber facing the upstream side in the reverse rotation direction and the gap between the second magnet roller and the inner wall facing the downstream side in the reverse rotation direction. The image forming apparatus according to claim 3, wherein the gap is smaller than the gap between the magnet roller and the magnet roller. 5. The developer discharge port of the mixing chamber is provided with a third magnet roller that can rotate in the forward and reverse directions and that rotates forward and supplies the developer in the mixing chamber.
The image forming apparatus described. 6. The third magnet roller has a gap between the inner wall of the mixing chamber and the third magnet roller that face each other on the upstream side in the reverse rotation direction and a gap between the inner wall that faces the third magnet roller on the downstream side in the rotation direction. The image forming apparatus according to claim 5, wherein the image forming apparatus is narrower than the above. 7. The image forming apparatus according to claim 5, wherein the third magnet roller in the mixing chamber is reversely rotated for a predetermined time and then is normally rotated to replenish the developer. 8. The image forming apparatus according to claim 5, wherein a reflux member is arranged in the vicinity of the inner wall of the mixing chamber facing the upstream side in the reverse rotation direction of the third magnet roller. 9. A method of supplying a developer to a developing chamber for forming an image by using the developer, wherein the developer after the image is formed is collected in a collecting chamber and the first magnet roller is normally rotated to perform the collecting and developing. A step of supplying the developer to the mixing chamber, a step of supplying the new developer in the supply chamber to the mixing chamber by the forward rotation of the second magnet roller, and a step of supplying the collected developer and the new developer in the mixing chamber. And a step of supplying the mixed developer from the mixing chamber to the developing chamber. The inner wall of the recovery chamber and the first magnet roller facing each other on the upstream side in the reverse rotation direction of the first magnet roller. Is narrower than the gap between the inner wall and the first magnet roller facing each other on the downstream side in the reverse rotation direction, and the developer is mixed by rotating the first magnet roller and the second magnet roller in the forward direction. Before feeding to the developer supply method characterized by reversely rotating the first magnet roller for a predetermined time. 10. A method of supplying a developer to a developing chamber for forming an image using the developer, wherein the developer after the image is formed is collected in a collecting chamber, and the collecting and developing is performed by forward rotation of a first magnet roller. A step of supplying the developer to the mixing chamber, a step of supplying the new developer in the supply chamber to the mixing chamber by the forward rotation of the second magnet roller, and a step of supplying the collected developer and the new developer in the mixing chamber. And a step of supplying the mixed developer from the mixing chamber to the developing chamber. The inner wall of the recovery chamber and the first magnet roller facing each other on the upstream side in the reverse rotation direction of the first magnet roller. Is narrower than the gap between the inner wall facing the downstream side in the reverse rotation direction and the first magnet roller, and the inner wall of the replenishing chamber facing the upstream side in the reverse rotation direction of the second magnet roller and the second magnet roller. The gap between the inner wall and the inner wall facing the downstream side in the reverse rotation direction.
It is configured to be narrower than the gap between the magnet roller and the first magnet roller and the second magnet roller before the first magnet roller and the second magnet roller are normally rotated to supply the developer to the mixing chamber. A method of supplying a developer, which comprises rotating in reverse for a predetermined time. 11. The step of agitating and mixing the recovered developer and the new developer in the mixing chamber comprises a gap between the inner wall of the recovery chamber and the third magnet roller, which face each other on the upstream side in the reverse rotation direction of the third magnet roller. 10. The structure is configured so as to be narrower than the gap between the inner wall and the third magnet roller that face each other on the downstream side in the reverse rotation direction, and the third magnet roller is reversely rotated for a predetermined time. Item 10. The developer supply method according to Item 10.