JP2001209286A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make exactly detectable that the storage amount of a developer having magnetism, collected and accumulated in a recovery container reaches a prescribed level by the magnetic sensor with a simple constitution, without causing a cost increase in a developer recoverying system. SOLUTION: The magnetic sensor 60 which detects that the storage amount of the developer GO(TO) in the recovery container 40 reaches a prescribed level is disposed on a device main body 1 side so that a detection surface 61 may face the recovery container 40. And, at least the region 45 opposed to the detection surface 61 of the magnetic sensor is constituted into the transformable structure deformed on the outer side of the recovery container 40 by being pushed with the accumulated developer GO (TO) of the recovery container 40 in the recovery container 40.

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 such as a copying machine, a printer, and a multifunction machine using an electrophotographic system, and more particularly, to an image forming apparatus using a magnetic developer. The present invention relates to an image forming apparatus including a developer collection system that collects unnecessary developer in a collection container.

[0002]

2. Description of the Related Art Generally, in an image forming apparatus using an electrophotographic method, an electrostatic latent image formed on an image carrier such as a photoconductor in accordance with image information is developed with a developer and then obtained by the development. The transferred image is transferred directly to a recording medium such as paper or through an intermediate transfer member to form an image. However, since a developer is generated that is not transferred to the image carrier and the like and remains, the residual image is formed. The developer is removed by a cleaning device and collected in a predetermined collection container.

In recent years, in an image forming apparatus using a two-component developer composed of a toner and a carrier as a developer, a new two-component developer (including a carrier) is installed in a developing machine that contains the two-component developer. Replenishment, and the deteriorated developer, which is not used for development and deteriorates and becomes unnecessary, overflows from the developing machine and is replaced little by little by a new two-component developer. Some devices employ a trickle developing system that suppresses the deterioration. However, the deteriorated developer generated by the trickle developing system is also collected in a predetermined collecting container.

In an image forming apparatus provided with a so-called developer collection system for collecting such unnecessary residual developer (toner component in the case of a two-component developer) and deteriorated developer in a collection container. The predetermined detecting means detects that the developer collected and accumulated in the collecting container reaches a predetermined level (for example, a level near full). Based on the detection information from the detection means, the image forming apparatus appropriately controls the image forming operation, and performs control processing for notifying a user or the like that it is time to replace the collection container.

In this case, in particular, a developer having a magnetic property (for example, a two-component developer composed of a magnetic toner containing a magnetic material and a non-magnetic carrier, a one-component developer composed of only a toner component containing a magnetic material) ), It is possible to use a magnetic sensor that detects a change in the magnetic permeability that fluctuates according to the amount of the magnetic developer and converts the change into an electric signal. .

[0006] In fact, the present applicant also discloses that, for example, in an image forming apparatus employing a trickle developing system, a magnetic sensor is provided on the outer peripheral surface of a collecting container in a developer collecting system for collecting the deteriorated developer generated in the trickle developing system. We offer technology that allows direct attachment.

[0007]

However, when the magnetic sensor is directly attached to the collection container, the collection container is replaced together with the collection container when the developer is accumulated and becomes full. Sometimes, the magnetic sensor is discarded together with the collection container, and the electrical connection (contact point) for sending the electric signal (detection signal) obtained by the magnetic sensor on the collection container side to the main body of the device is collected. Parts such as magnetic sensors are wasted every time the collection container is replaced, and the cost is increased due to the wasted parts and the construction of electrical connections. There was a problem. On the other hand, when the collection container is filled with the developer and the developer is discarded and the collection container is reused when the collection container becomes full, construction such as the electrical setting described above is still necessary. Therefore, there is a problem that the cost is unavoidable.

As the detecting means, it is possible to use an optical sensor which detects the presence or absence of light transmission or reflection in the collection container by combining a light emitting element and a light receiving element, and converts it into an electric signal. is there.

However, in this case, since the developer (particularly, the toner component, which is a powder) adheres to the inner surface of the collection container and interrupts the light path, the detection by the optical sensor cannot be performed accurately or There is a problem that it cannot be done at all. That is, even though the accumulated amount of the developer in the collection container has not reached the predetermined level, it may be erroneously detected that the developer has reached the predetermined level. In addition, such erroneous detection by the optical sensor may cause the relatively heavy deteriorated developer including the carrier component to be recovered, particularly when the residual developer and the deteriorated developer are collected in the same collection container. When the developer is dropped and thrown into the collection container, the relatively light residual developer (toner) already collected in the container flies up in the container and easily adheres to the inner surface of the container. Become.

Japanese Patent Application Laid-Open No. Hei 9-190066 discloses that when a developing device having a developer container is mounted on the image forming apparatus main body, the developing device is in contact with the wall surface of the developer container and the remaining amount of developer in the container. An image forming apparatus is described in which a level sensor (magnetic sensor) capable of detecting is provided on the apparatus main body side. This publication also discloses that a positioning means is provided for bringing the detection surface of the level sensor into contact with the wall surface of the developer container.

However, this publication discloses a magnetic sensor,
There is no description that teaches application to detect that the accumulated amount of the developer in the collection container in the developer collection system has reached a predetermined level. In other words, the magnetic sensor disclosed in this publication merely shows a use mode in which the magnetic sensor must always be kept in contact with the wall surface of the developer container after the developing device is mounted on the apparatus main body. Further, since the positioning means described in this publication is a support mechanism that supports the magnetic sensor in a displaceable state and in a state where the magnetic sensor is pressed against the wall surface of the developer container, the supporting structure is separate from the magnetic sensor. Components are required, and the cost increases accordingly. Moreover, the state of contact between the detection surface and the wall surface of the developer container is governed by the dimensional accuracy of the wall surface of the developer storage container, and the like.
Irrespective of the mounting state of the developing device, the state of contact between the wall surface and the sensor may be poor, and as a result, detection by the magnetic sensor may not be accurate.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has led to an increase in cost because the amount of magnetic developer collected and collected in a collection container has reached a predetermined level. It is a main object of the present invention to provide an image forming apparatus having a simple configuration and capable of accurately detecting by a magnetic sensor.

[0013]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides an image forming system for forming an image by developing with a developer having magnetism, and recovers a developer that is not required in the image forming system. And a developer collecting system for detecting, by a magnetic sensor, that the accumulated amount of developer collected and accumulated in the collection container has reached a predetermined level. A magnetic sensor is disposed on the apparatus body side such that a detection surface thereof faces the collection container, and at least a portion of the collection container facing the detection surface of the magnetic sensor is accumulated in the collection container. This is an easily deformable structure that is pushed by the developer and deforms outside the collection container.

According to the image forming apparatus of the present invention, the recovery container in the developer recovery system and the magnetic sensor disposed on the apparatus main body are used in the initial stage (before or after the developer is recovered). In the stage before the accumulated amount reaches the predetermined level), at least the facing state is set. At this time, the portion of the collection container that is to be easily deformed may or may not be in contact with the detection surface of the magnetic sensor. In the case of further contact, the contact surface may be partially contacted with the detection surface, such as contact in an oblique state.

When the unnecessary developer having magnetism is collected in the collection container and accumulated to some extent (at a time when a predetermined level is reached) by the developer collection system,
At least a portion of the collection container having an easily deformable structure facing the detection surface of the magnetic sensor is pushed by the accumulated developer and is deformed to the outside of the collection container so that the collection container comes into close contact with the detection surface of the magnetic sensor. (Or more reliably). As a result, the detection surface of the magnetic sensor is brought into a state in which the detection surface of the magnetic sensor is evenly approached to the developer in the container via the collection container (a state in which normal detection is guaranteed). This makes it possible to appropriately detect a change in magnetic permeability that fluctuates in accordance with the amount of the developer, thereby accurately detecting that the accumulated amount of the developer has reached a predetermined level.

In the present invention, the easily deformable structure of the collecting container is easily deformed to the outside of the container (strictly toward the detection surface of the magnetic sensor) by being pushed by the accumulated developer, and finally to the magnetic field. The structure is not particularly limited as long as it can be in close contact with the detection surface of the sensor. For example, the structure includes a bellows or a thin portion.

In this case, it is possible to manufacture and provide a collection container having a portion having an easily deformable structure more simply and inexpensively. The easily deformable structure including the bellows part is, for example,
A bellows structure that deforms so that it expands and contracts (strictly stretches) outside the collection container is used, so that the surface above the bellows can finally come into close contact with the detection surface of the magnetic sensor due to the bellows stretching. It is the structure which did. Further, the easily deformable structure including a thin portion includes, for example, a structure in which a portion having a relatively small thickness as compared with the thickness of another portion of the collection container is provided, and the thin portion contributes at least to deformation. It is.

In the present invention, the developer recovered by the developer recovery system is not particularly limited as long as it is a magnetic developer which is unnecessary in the image forming system. For example, it is a two-component developer composed of a non-magnetic toner and a magnetic carrier, and is a deteriorated developer that is not used for development in the image forming system and deteriorates and becomes unnecessary. This deteriorated developer is a two-component developer generated in the trickle developing system as described above.

In addition, the developer recovered by the developer recovery system includes both the deteriorated developer described above and residual toner that remains after use in the image forming system and is cleaned and removed by the cleaning device and becomes unnecessary. It may be.
Further, it may be a magnetic one-component developer (toner).

Further, according to the present invention, the image forming system develops a latent image formed in accordance with image information with a magnetic developer to form an image (toner image), and finally forms the image. Any material may be used as long as it can be transferred and formed on a recording medium such as plain paper, coated paper, an OHP sheet, and an envelope.

[0021]

[First Embodiment] FIGS. 1 and 2
1 shows an image forming apparatus according to Embodiment 1 of the present invention, FIG. 1 is a schematic diagram mainly showing an image forming system in the image forming apparatus, and FIG. 2 is a diagram showing a developer collecting system in the image forming apparatus. It is a schematic diagram mainly shown.

First, as shown in FIG. 1, this image forming apparatus has four toner images of black (K), yellow (Y), magenta (M), and cyan (C), respectively. Imaging units 10K, 10Y, 10M,
10C and the respective image forming units 10K, 10Y, 10
M and an intermediate transfer mechanism 20 that rotates an intermediate transfer belt 21 on which a toner image formed by 10C is temporarily transferred.
And an imaging system comprising:

Each of the image forming units 10 forms a toner image by an electrophotographic process, and is disposed at a predetermined interval in the horizontal direction. Each of the image forming units 10 is basically a photosensitive drum 1 as an image carrier that is arranged to rotate in the direction of arrow A.
1, a charging device 12, a latent image forming device (13), a developing device 14, a transfer device (transfer roll) 15, and a drum cleaner 16 disposed in a predetermined positional relationship in the vicinity of the periphery of the photosensitive drum 11. Its main part is configured. Of these, the developing device 14 contains a two-component developer G composed of a non-magnetic toner composed of each color component and a magnetic carrier, and replenishes a new two-component developer G with a developer replenishing device (not shown). A trickle developing method for discharging the deteriorated developer is adopted.

The intermediate transfer mechanism 20 rotates in the direction of arrow B so as to pass through the intermediate transfer belt 21 and the transfer position of the photosensitive drum 11 in each of the image forming units 10 while supporting the intermediate transfer belt 21. The driving roll 22, the driven roll 23, the tension roll 24, the backup roll 25, and the belt cleaner 26, which are to be run, constitute main parts thereof.

In FIG. 1, reference numeral 30 denotes a secondary transfer roll which is disposed to face the backup roll 25 to constitute a secondary transfer portion, 31 denotes a storage tray for storing paper P, and 35 denotes a roll nip type heating. The fixing device 36 is a transport belt device that transports the paper P after the secondary transfer to the fixing device 35. R1 is a paper feed path for feeding the paper P stored in the storage tray 31 to the secondary transfer unit, and is configured by a delivery roll 32, a transport roll 33, a registration roll 34, and the like. Further, R2 is a paper discharge path for discharging the fixed paper P, R3 is a double-sided conveyance path including a reversing path for reversing the fixed paper P during double-sided image formation and re-sending the paper P to the paper supply path R1, Reference numerals 37 denote switching gates for switching the conveyance path of the sheet P after fixing to either the sheet discharge path R2 or the double-sided conveyance path R3. 1 indicate each transport path (path) of the sheet P.

In an image forming apparatus having such an image forming system, an image is formed as follows.

First, in each image forming unit 10, after the photosensitive drum 11 rotating in the direction of arrow A is uniformly charged by the charging device 12, the image on the charged surface is subjected to color separation from the latent image forming device. An electrostatic latent image is formed by scanning and exposing a laser beam (arrow) 13 corresponding to the data, and then the latent image is developed by a developer G of a predetermined color component supplied from a developing device 14. Thus, a toner image of each color is formed. Thereby, each photosensitive drum 11
On the top, toner images of four colors of yellow, magenta, cyan, and black are individually formed. Next, the toner images of the four colors are electrostatically primary-transferred so as to be superimposed on the surface of the intermediate transfer belt 21 passing between the photosensitive drum 11 and the transfer device 15, and then are transferred through the paper feed path R1. The sheet P is electrostatically secondary-transferred to the sheet P conveyed to the secondary transfer unit via the second transfer unit. Finally, the sheet P after the transfer of the toner image
Is sent to pass through the nip portion between the heating roll 35a and the pressure roll 35b in the fixing device 35, and the toner image is thermally fixed. Thereafter, the toner image is discharged out of the apparatus main body through the paper discharge path R2.

Through the above process, the paper P
Is formed on one side. In addition, when the double-sided image forming mode is selected, the sheet P on which image formation on one side has been completed is re-fed to the sheet feeding path R1 via the double-sided conveying path R3 in a reversed state, and the secondary transfer unit To form an image on the second surface. When forming a black and white image, a black and white image is formed by operating only the black image forming unit 10K among the four image forming units 10. Further, the residual toner which is not transferred to and adheres to the photosensitive drum 11 after the primary transfer is removed and cleaned by the drum cleaner 16. Further, the residual toner that is not transferred to the intermediate transfer belt 21 after the secondary transfer and remains is cleaned and removed by the belt cleaner 26.

On the other hand, on the rear side of the image forming apparatus, as shown in FIG. 2, deterioration caused by a trickle developing method in the developing devices 14 of the image forming units 10K, 10Y, 10M, and 10C in the image forming system. A developer GO;
A developer recovery system is provided for recovering residual toner TO generated by cleaning and removal by the drum cleaner 16 of each of the image forming units 10K, 10Y, 10M, and 10C.

As shown in FIGS. 2 to 4, the developer collection system includes one collection box 40 which is detachably attached to the apparatus main body 1, and each developing device 14 And a transport mechanism 50 for transporting the deteriorated developer GO and the residual toner TO generated respectively by the drum cleaner 16 and the deteriorated developer GO and the residual toner TO which are transported by the transport mechanism 50 and collected in the collection box 40. A magnetic sensor 60 for detecting that the accumulated amount has reached a predetermined level and a mounting detection sensor 70 for detecting whether or not the collection box 40 is mounted are mainly configured.

The transport mechanism 50 includes the developing devices 1
The deteriorated developer conveying pipe 51 having a built-in rotary conveying member for conveying the deteriorated developer GO discharged from the drum 4, and the residual developer having a built-in rotary conveying member for conveying the residual toner TO discharged from each drum cleaner 16 are provided. Toner transport pipe 5
2, a merged conveying pipe 53 for merging (mixing) the deteriorated developer GO or the residual toner TO conveyed by the conveying pipes 51 and 52, respectively, and convey the pipes to the merged conveying pipe 53. The falling / mixing pipe 54 which discharges and drops the deteriorated developer GO or the residual toner TO from the end portions of 51 and 52 and sends them while mixing them is connected to the end portion of the merge / convey pipe 53 in a state where it is lowered one step and joins. A discharge pipe 55 for discharging the deteriorated developer GO or the residual toner TO conveyed by the conveyance pipe 53 from the discharge port 55a to the collection box 40 and dropping it. In FIG. 2 and FIG.
Reference numeral 6B denotes a rotary transport member (auger) having a spiral projection formed on a rotary shaft, which is disposed so as to rotate in the merge transport pipe 53 and the discharge pipe 55 to transport the developer and the like.
7A and 57B are drive motors for rotating the augers 56A and 56B, respectively.

As shown in FIGS. 3 to 5, the collecting box 40 is a plastic molded container (for example, a blow-molded product such as polypropylene) having a substantially rectangular shape. It has a sufficient capacity (volume). The collection box 40
Is mainly provided with a developer inlet 41 and an air vent 42 for taking in the developer and the like which is conveyed by the conveying mechanism 55 and discharged from the discharge port 55a of the discharge pipe 55 on the upper surface of the box. A holding portion (handle) 43 for holding the collection box by hand is recessed on one side of a wide surface 40a positioned on the apparatus main body 1 side of the four box side surfaces, slightly inward of the entire side surface 40a. Each of the concave portions 44 is formed in an indented state.

Further, as shown in FIG. 4 and FIG. 7, the entire collection box 40 accommodates the collection box 40 in a box installation space formed on the rear side of the image forming apparatus main body 1. Box support frame 80 in the shape of a box with an opening at the top and of a size that allows
It is housed in and supported by. The box support frame 80 is set upright on a support take-out position (the state shown in FIG. 7A), which is tilted toward the rear side of the apparatus, about a support shaft 81 provided on the bottom side thereof. It is mounted so as to be able to swing between the collection mounting position (the state shown in FIG. 7B). Further, a portion (opening 82) of the support frame 80, which is opposed to the sensors 60 and 70, is also opened. After the collection box 40 is stored in the box support frame 80, when the deteriorated developer or the like to be collected is almost full, the collection box 40 is taken out of the support frame 80 and replaced with a new empty collection box. ing.

As shown in FIGS. 3 and 4, the magnetic sensor 60 has a disk-shaped detection surface 61 formed so as to protrude from the sensor main body.
In 1, a change in the magnetic permeability of the collected developer (actually, the magnetic carrier in the deteriorated developer GO) to be detected can be detected and converted into an electric signal. Also,
The magnetic sensor 60 has a detection surface 61 on the side of the image forming apparatus main body 1 whose detection surface 61 is located at a position near the concave portion 44 of the collection box 40 (accumulated amount of developer to be detected by the magnetic sensor 60, that is, a “predetermined level”). Equivalent height position)
And is provided in a fixed state at a position facing the same. On the other hand, the mounting detection sensor 70 has a push switch 71 formed so as to protrude from the sensor main body, and is turned ON / OFF when the push switch 71 is pushed or the pushing is released.
Can be converted into an electric signal. The mounting detection sensor 70 is located on the side of the image forming apparatus main body 1, and the push-in switch 71 of the mounting detection sensor 70 is
Are provided in a fixed state at a position facing a part of.

In this developer collection system, at least a portion 45 of the collection box 40 facing the detection surface 61 of the magnetic sensor 60 is attached to the collection box 4.
The structure is such that the deteriorated developer GO and the residual toner TO accumulated in the inside of the box 0 pushes the box and easily deforms to the outside of the box (an easily deformable structure).

In this embodiment, the collection box 40
As shown in FIG. 6, the portion 45 is formed into a cylindrical shape formed by recessing the inside of the box from the side surface 40a located on the side facing the apparatus main body 1 and then rising again to the outside of the box. Has a bellows-like shape 46 whose side portion is easy to expand and contract, and a flexible flat surface 47 whose cylindrical tip portion can contact the sensor detection surface. Unlike the other portions of the side surface 40a, the portion 45 having the projection structure including the bellows-shaped portion 46 is different from the other portions of the side surface 40a in that the developer and the like GO collected and deposited inside the collection box 40 are GO,
TO pushes from the inside of the box 40 to the outside (strictly toward the detection surface 61 side of the magnetic sensor 60) (arrow F in FIG. 6b indicates the pressing force at that time), and the bellows-shaped side portion 46 expands and deforms to bulge out of the box. As a result, the position of the flat surface 47 at the tip is displaced outside the box 40. At this time, the displacement amount (distance) of the flat portion 47 is set to a level that can sufficiently reach the detection surface 61 of the magnetic sensor 60 located on the side facing the portion 45.

Next, the operation of the developer collecting system will be described.

First, the collection box 40 is moved to the apparatus main body 1.
Attach to the side. That is, the collection box 40 is set in FIG.
As shown in FIG. 7B, after being opened so as to be tilted to the rear side of the apparatus main body 1 and inserted so as to be inserted into the inside of the box support frame 80 at the storage and take-out position, the support frame 80 is placed in the vertical state as shown in FIG. And set it in the collection mounting position.

At this time, the side surface portion (recess 44) of the collection box 40 exposed from the opening 82 of the box support frame 80 pushes the push switch 71 of the mounting detection sensor 70, whereby the box support frame 80 is closed and collected. It is detected that the box 40 has been mounted. Incidentally, when the support frame 80 in which the collection box 40 is not accommodated is closed, the mounting detection sensor 7
Since there is nothing to press the 0 push switch 71, the mounting of the collection box is not confirmed. Further, when the collection box 40 is mounted, as shown in FIG. 4, the developer intake port 41 on the upper surface of the box is connected to the discharge port 55a of the discharge pipe 55 of the developer collection system. Become. Further, at this point, the portion 45 of the easily deformable structure of the collection box 40 and the magnetic sensor 6
It may or may not be in contact with the zero detection surface 61. In this example, description will be made on the assumption that no contact is made (see FIG. 8A).

When the image forming operation is performed, the deteriorated developer GO generated in the developing device 14 of each image forming unit 10 and the residual toner TO generated in the drum cleaner 16 of each image forming unit 10 during that time. Is the transport mechanism 50
And is collected in the collection box 40.

First, the deteriorated developer GO starts to be transported by the deteriorated developer transport pipe 51 and the residual toner TO
Starts to be conveyed by the residual toner conveying pipe 52, and is discharged so as to fall through the falling mixing pipe 54 at the end of each of the pipes 51 and 52, and is sent to the merged conveying pipe 53.

Here, the deteriorated developer transport pipe 51 of the developing device 14 of the adjacent image forming unit 10 and the residual toner transport pipe 52 of the drum cleaner 16 are connected to one drop mixing pipe 52a. Its each pipe 5
The deteriorated developer GO and the residual toner TO, which are discharged and dropped from the first and the second 52, fall and mix so as to diffuse in the internal space of the drop mixing pipe 52a. As a result, the residual toner TO having relatively poor fluidity is sent to the merged transport pipe 53 in a state where the residual toner TO is mixed with the deteriorated developer GO having good fluidity. It is satisfactorily transported without clogging the TO.

The deteriorated developer GO and the residual toner TO which are merged and conveyed by the merged conveyance pipe 53 are finally delivered to the discharge pipe 55 and then discharged and dropped from the discharge port 55a. Thereby, the deteriorated developer GO and the residual toner TO
Are collected in the collection box 40 through the developer inlet 41.

Then, in this way, the collection box 40
The deteriorated developer GO and the residual toner TO collected in FIG.
As shown in FIG. 8A, the deposit gradually starts to be accumulated in the collection box 40, and eventually reaches the height of the collection box 40 up to the portion 45 of the easily deformable structure (FIG. 8).
b).

In such a state, the collection box 4
As shown in FIGS. 6B and 8B, the above-described portion 45 is pushed from the inside to the outside of the collection box 40 by the accumulation pressure of the deteriorated developer GO and the residual toner TO that accumulate. The bellows portion 46 is expanded and deformed so as to bulge out of the box. Finally, the tip 47 of the portion 45 is connected to the detection surface 61 of the magnetic sensor 60.
It is in a state of contact so as to be in close contact with.

Thus, the detection surface 6 of the magnetic sensor 60
1 is a state in which the degraded developer GO deposited via the side surface 40a of the collection box 40 (strictly, the front end portion 47 of the portion 45) is evenly approached, that is, a state in which normal detection is guaranteed. , The magnetic sensor 60 is located in the collection box 4.
A change in magnetic permeability that fluctuates in accordance with the amount of the deteriorated developer GO (magnetic carrier thereof) accumulated in 0 is properly detected and converted into an electric signal. As a result, the collection box 40
It accurately detects that the accumulated amounts of the deteriorated developer GO and the residual toner TO have reached a predetermined level (a state close to being full).

In this image forming apparatus, when the detection signal of the magnetic sensor 60 is obtained, first, a warning message such as "It is time to replace the collection box" is displayed on the liquid crystal display section of the operation panel or the like, and the user is prompted. The replacement of the collection box 40 is encouraged.

The operation of mounting the collection box 40 may be performed in the reverse order. At the time of non-image formation, the box support frame 80 is first opened so as to be tilted to the rear side of the apparatus main body 1 and the storage and unloading position. 7 (FIG. 7a), the collection box 40 in a state of being almost full is pulled out from the inside of the support frame 80 by pulling it out. Thereafter, the empty new collection box 40 is accommodated in the support frame 80, and the support frame 80 is closed so as to return to the collection mounting position, thereby completing the replacement.

In this image forming apparatus, for example, if the box support frame 80 is erroneously opened during the image forming operation, the operation is detected by the mounting detection sensor 70 and based on the detection signal. Thus, the operations of the augers 56A and 56B in the merging and conveying pipe 53 and the discharging pipe 55 in the developer recovery system are stopped. Thus, it is possible to avoid troubles such as the developer and the like to be collected being scattered and stained in the apparatus main body. In this case, only the operations of the augers 56A and 56B are stopped, and the image forming operation on the way is not stopped until the series of operations (jobs) is completed. This allows
During the image forming operation, the plurality of sheets P conveyed in the image forming apparatus are not left in the apparatus due to the interruption of the operation, and the operation of removing the left sheets is unnecessary.

Further, in this image forming apparatus, when the control for the erroneous opening operation of the box support frame 80 is executed, unless the opened support frame 80 is closed and returned (that is, the detection by the mounting detection sensor 70). Until the next operation, the recovery operation by the developer recovery system (the stopped auger) and the next image forming operation by the image forming system or the like cannot be started. This not only avoids the contamination caused by the collected developer being scattered in the apparatus main body, but also allows the developer to be collected in a state where the auger is stopped so that any one of the transport mechanisms 50 can be used. It is also possible to prevent the developer from being clogged with such a transport pipe.

[Other Embodiments] In the first embodiment, the case where the recovery box 40 has a projecting structure having a bellows shape 46 as the portion 45 having an easily deformable structure is exemplified. As shown in FIG. 9, a predetermined area of the side surface 40 a of the collection box 40 facing the detection surface 61 of the magnetic sensor 60 is depressed inward by one step to form a step, and the thickness thereof is more easily deformed than the side surface 40 a. It may be a planar structure having a thinned portion 48 that is thinner.

When the planar structure having the thin portion is employed, as shown in FIG. 9B, when the recovered deteriorated developer GO or the like is accumulated up to the portion 45, the planar structure is removed. The thin portion 48 of the portion 45 becomes deformed so as to swell outside the box by being pushed by the accumulated deteriorated developer GO, and finally the thin portion 48 comes into close contact with the detection surface 61 of the magnetic sensor 60.

Thus, the detection surface 6 of the magnetic sensor 60
1 is a state in which the degraded developer GO deposited via the side surface 40a of the collection box 40 (strictly, the thin portion 48 of the portion 45) is evenly approached, that is, a state where normal detection is guaranteed. , The magnetic sensor 60 detects the deteriorated developer G in the collection box 40 as in the case of the first embodiment.
It is possible to accurately detect that the accumulated amount of O and the residual toner TO has reached a predetermined level.

In the first embodiment, the case where the image forming system includes the plurality of image forming units 10 and the intermediate transfer mechanism 20 is exemplified. However, other units may be used. An image forming system including one image forming unit or an image forming system having no intermediate transfer mechanism may be used. Further, the example in which both the deteriorated developer and the residual toner are collected as the developer collection system has been described, but a developer collection system that collects only the deteriorated developer may be used. Further, the developer to be collected may be a magnetic one-component developer.

[0055]

As described above, according to the image forming apparatus of the present invention, the magnetic sensor in the developer collection system is disposed on the main body of the apparatus such that the detection surface thereof faces the collection container. Since at least the portion facing the detection surface of the magnetic sensor has an easily deformable structure, it is determined by the magnetic sensor that the accumulated amount of magnetic developer collected and accumulated in the collection container has reached a predetermined level. It can be detected accurately. Moreover, in order to realize accurate detection with such a magnetic sensor, no special components are required for the installation of the magnetic sensor, and a predetermined part of one of the collection containers is easily deformed. Since it is only necessary to adopt a simple configuration of the structure, it is possible to easily cope with this without causing a significant increase in cost.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a main part (mainly an image forming system) of an image forming apparatus according to a first embodiment.

FIGS. 2A and 2B show another main part (mainly, a developer recovery system) of the image forming apparatus of FIG. 1, wherein FIG. 2A is a schematic diagram viewed from the front side of the apparatus, and FIG. Schematic view of Sotoyuo viewed from the top.

FIG. 3 is a schematic cross-sectional view showing a configuration of a collection box of a developer collection system and its vicinity, as viewed from the rear side of the apparatus main body.

FIG. 4 is a schematic cross-sectional view showing the state of the collection box of FIG. 3 and its surroundings viewed from one side surface of the apparatus main body.

5 (a) is a front view of the collection box, FIG. 5 (b) is a sectional view taken along line BB of FIG. 5 (a), and FIG. 5 (c).
Is its top view.

FIGS. 6A and 6B show a configuration of a portion of the collection box according to the first embodiment, which is formed of an easily deformable structure, where FIG. 6A is a side view and FIG. 6B is a longitudinal sectional view of FIG.

FIGS. 7A and 7B show a collection box and a support frame thereof, wherein FIG. 7A is a schematic cross-sectional view in a state of being stored and taken out, and FIG.

FIGS. 8A and 8B show the relationship between the magnetic sensor and the portion of the collection box having an easily deformable structure in the first embodiment, wherein FIG. 8A is a cross-sectional explanatory view showing a state before detection, and FIG. Sectional explanatory drawing which shows a state.

9A and 9B show another configuration example of a portion of the collection box having an easily deformable structure, in which FIG. 9A is a cross-sectional explanatory view showing a state before detection, and FIG. 9B is a cross-sectional explanatory view showing a state at the time of detection. FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Device main body, 10 ... Image forming unit (part of image forming system), 20 ... Intermediate transfer mechanism (part of image forming system), 4
0: collection box (collection container), 45: site facing the detection surface, 46: bellows portion, 48: thin portion, 50: transport mechanism (part of the developer collection system), 60: magnetic sensor, 61: detection Surface, GO: deteriorated developer (developer having magnetism), TO: residual toner.

Claims (4)

[Claims] An image forming system for developing an image by developing with a magnetic developer, collecting a developer unnecessary in the image forming system into a collecting container, and collecting and accumulating the developer in the collecting container. And a developer collection system for detecting, by a magnetic sensor, that the accumulated amount of developer has reached a predetermined level, wherein the magnetic sensor has a detection surface facing the collection container. And at least a portion of the collection container facing the detection surface of the magnetic sensor is pressed by the developer accumulated in the collection container and deformed to the outside of the collection container. An image forming apparatus having an easily deformable structure. 2. The image forming apparatus according to claim 1, wherein the easily deformable structure of the collection container is a structure including a bellows or a thin portion. 3. The developer collected by the developer collection system is a two-component developer comprising a non-magnetic toner and a magnetic carrier, and is not used for development in the image forming system and deteriorates and becomes unnecessary. The image forming apparatus according to claim 1, wherein the image forming apparatus is a deteriorated developer. 4. The developer collected by the developer collection system is both the deteriorated developer and residual toner that remains after use in the image forming system and is cleaned and removed and becomes unnecessary. The image forming apparatus according to claim 3, wherein: