JP3923905B2 - Image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a developing device for developing an electrophotographic photosensitive member, a process cartridge configured by combining the developing device and a cleaning device, and an image forming apparatus such as a copying machine, a printer, and a facsimile including the developing device and the process cartridge. .
[0002]
[Prior art]
In recent years, in an electrophotographic image forming apparatus such as a copying machine or a laser beam printer, an electrophotographic photosensitive member, a charging device, a developing device, a cleaning device, etc. are integrated into a process cartridge, and this process cartridge is removed and replaced. Techniques for improving the maintainability of the apparatus have been proposed and put into practical use.
[0003]
Such a developing device has the following advantages.
(1) There is no need to replenish developer (hereinafter referred to as toner) and processing of used toner (hereinafter referred to as waste toner) in the cleaning means, and the user performs maintenance in a batch and in a simple manner. be able to.
(2) Parts having a predetermined lifetime such as the photosensitive drum need not be replaced separately, and can be replaced in a batch.
(3) Although the above-described operations (1) and (2) have been conventionally performed by specialized engineers, they can be easily performed by general users.
(4) The function can be easily changed (e.g., color exchange) by exchanging process cartridges having different functions (e.g., color).
[0004]
However, in recent years, the lifetime of the photoconductor has been increased with the progress of technology, and therefore the time to be originally replaced in the process cartridge as described above may vary greatly depending on the parts. In this case, when the process cartridge is replaced as a whole, it will be replaced in accordance with the part having the shortest life. Therefore, even though the part can still be used, it is replaced and discarded. It will end up. In some ways, this is a waste of resources.
[0005]
Therefore, it is conceivable to divide the process cartridge as described above into two parts to enable independent handling, and to change the replacement timing of each cartridge. For example, it is divided into a first process cartridge including a long-life photosensitive member, a charging device, and a cleaning device, and a second process cartridge including a developing device. It is conceivable to replace the first process cartridge at the time when image formation of ˜3000 sheets is performed and to replace the first process cartridge as the lifetime when image formation of 5,000 to 20,000 sheets is performed.
[0006]
However, in this case, the treatment of waste toner removed from the surface of the photoreceptor by the cleaning device becomes a problem. That is, since the first process cartridge has a long life, the amount of waste toner in the cleaning device becomes enormous, which leads to an increase in the size of the first process cartridge and an increase in the size of the apparatus main body. In addition, in the case of a cartridge in which all the members are integrated, since the toner more than the toner initially filled in the developing device does not accumulate in the cleaning device, there is no problem if it is held in each amount, If the developing device and the cleaning device as described above are separated, there is a possibility that waste toner exceeding the capacity can be accumulated until the replacement time depending on the usage, which may impede the cleaning performance or remove the toner from the cleaning device. There is a risk of overflow.
[0007]
It is also conceivable that a waste toner storage container is provided as in a conventional general copying machine, and waste toner is collected in this container, and the user occasionally throws it away. However, it is considered that a means for detecting the waste toner container and the amount of toner accumulated in the container is required, and that it is unnecessary for the user to throw away the toner one by one.
[0008]
In order to solve the above problem, a process cartridge that can be attached to and detached from the image forming apparatus main body, a waste toner storage portion that stores waste toner removed by cleaning means provided separately from the cartridge, and electrophotography There has been proposed a technique including a developing unit that develops an electrostatic latent image on a photoreceptor and a supporting unit that integrally supports the waste toner storage unit and the developing unit (see, for example, Patent Document 1).
[0009]
[Patent Document 1]
Japanese Patent Publication No. 63-10424 [0010]
[Problems to be solved by the invention]
However, in such a technique, the waste toner removed by the cleaning device is discarded as it is, and thus the device for extending the life of the second process cartridge has been insufficient.
[0011]
SUMMARY OF THE INVENTION An object of the present invention is to provide a developing device that solves the above-mentioned conventional problems easily and inexpensively, improves maintainability, reduces costs, extends the service life, and is environmentally friendly.
[0012]
Another object of the present invention is to provide a process cartridge that can prevent toner drop when the waste toner path and the developing device are attached and detached, has good maintainability, and has a long life.
[0013]
Another object of the present invention is to provide an image forming apparatus excellent in maintainability, cost, life, and environmental performance.
[0014]
[Means for Solving the Problems]
The image forming apparatus according to claim 1 of the present invention, in order to achieve the above object, an image forming apparatus including a developing device for developing an electrostatic latent image on the electrophotographic photosensitive member, said developing device, the developing A toner container that receives reusable toner out of waste toner removed by a cleaning device provided separately from the apparatus; a waste toner container that receives toner unsuitable for reuse; and the toner A flexible wall that separates the storage unit and the waste toner storage unit, and the waste toner removed by the cleaning device can be reused in the middle of the waste toner transport path removed by the cleaning device A separation device for separating the toner into a non-reusable toner and a toner that divides the conveying path into two parts, and one of the waste toners receives a reusable toner among the waste toners The container can be connected to a waste toner container that receives toner that is not suitable for reuse, and the toner container and waste toner container can be connected to the leading end of the transport path or the vicinity of the leading end. It is characterized in that opening means is provided for feeding reusable toner to the toner storage portion opened when the toner is mounted and toner unsuitable for reuse to the waste toner storage portion.
[0015]
According to a second aspect of the present invention, in order to achieve the above object, in the image forming apparatus of the first aspect, the first process cartridge is supported by integrally supporting the cleaning device together with the electrophotographic photosensitive member by a housing. When the developing device is a second process cartridge that is separate from the first process cartridge and can be attached and detached independently of the first process cartridge, and both the process cartridges are mounted on the image forming apparatus main body. a toner reusable said opening means is opened, and the waste toner and the above-mentioned toner container, respectively, wherein Rukoto such as a receivable in the waste toner storing portion.
[0016]
According to a third aspect of the present invention , in order to achieve the above object, in the image forming apparatus of the second aspect, a cap having an opening is provided at the tip of the transport path, and the process cartridge can be attached and detached at the opening of the cap. Correspondingly, characterized in Rukoto to open and close the opening at the tip or leading end vicinity of the transport path of the first process cartridge side.
[0017]
Those according to the fourth aspect, in order to achieve the above object, an image forming apparatus according to claim 3, the opening of the cap, and wherein the biasing Citea Rukoto to close by the urging member .
[0018]
Those according to the claim 5, in order to achieve the above object, Oite the image forming equipment according to claim 3 or 4, the tip of the cap is provided with protrusions, the said second process cartridge first When mounting on the process cartridge, the protrusion is pushed by the outer wall surface of the second process cartridge to open the opening of the transport path .
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a cross-sectional view of a main part of a copying apparatus which is an embodiment of an image forming apparatus according to the present invention. The illustrated copying apparatus 1 is an apparatus using electrophotography, and a photosensitive drum 2 provided with a photoconductive layer on a conductive drum base is pivotally supported in the direction of the arrow in the figure. Around the photosensitive drum 2, a corona discharge device 3, a short focus optical element array 4, a developing device 5, a transfer corona discharge device 6, and a cleaning device 7 are arranged according to the rotation direction. A discharger 3 and a cleaning device 7 are integrally supported by a housing 8 together with the photosensitive drum 2 (this is referred to as a first process cartridge A). The housing 8 is guided and supported by a guide rail 9 fixed on the apparatus main body 1a side of the copying apparatus 1, and is attached to and detached from a predetermined receiving portion of the apparatus main body.
[0020]
On the other hand, the developing device 5 is separated from the first process cartridge A, and is supported by guide rails 20 and 21 fixed on the apparatus main body 1a side, and can be detached from the first process cartridge A independently. (This is called the second process cartridge B). The developing device 5 has a hopper 5a for storing toner in the upper portion and a waste toner storage portion 5c for storing waste toner discharged from the cleaning device, and a rotating body for supplying toner to the photosensitive drum 2 in the lower portion. It is of the well-known structure which has 5b. As the toner, a one-component developer using a magnetic toner or a two-component developer having a toner and a magnetic carrier is used. Further, as the rotating body 5b, a rotating magnetic roller having a magnetic pole on the surface, or a magnetic roller having an internal magnetic roller and a nonmagnetic sleeve provided along the peripheral surface thereof is used. As the cleaning device 7, a member using a blade plate as a member for removing toner from the surface of the photosensitive drum 2 or a member using a fur brush is used. In the illustrated embodiment, the developing device 5 uses a one-component magnetic toner, a rotating body having a magnetic roller therein, and the cleaning device 7 uses a blade plate.
[0021]
In the illustrated copying apparatus 1, the surface of the photosensitive drum 2 is uniformly charged with a predetermined polarity by a corona discharger 3, and then a document on a document table 10 that reciprocates on the upper part of the apparatus body 1 a is illuminated by a lamp 11. The reflected light is exposed on the drum 2 through the focus optical element array 4 to form a latent image. The formed latent image is developed by the developing device 5, and the developed image is transferred to the transfer material by the transfer corona discharger 6. The transfer material is supplied to the transfer material supply tray 12 by an operator's manual operation, and is conveyed to the transfer unit via the conveyance roller 13 and the timing roller 14. The transfer material that has been transferred is separated by the separating member 15, sent to the fixing device 17 via the moving path 16 to fix the image, and further sent onto the paper discharge tray 19 via the discharge roller 18.
[0022]
2 is a perspective view showing the attachment / detachment relationship between the apparatus main body 1a and the first process cartridge A, and FIG . 3 is a schematic diagram showing the internal structure of the copying apparatus 1. As shown in FIG . The first process cartridge A containing the photosensitive drum 2 is performed by opening the front door 22 of the apparatus main body 1a and manually pulling out or pushing the housing 8 along the guide rail 9 by the operator. An arrow 23 in the figure indicates the moving direction of the first process cartridge A when the first process cartridge A is attached or detached.
[0023]
When the first process cartridge A is taken out, the second process cartridge B is taken out from the apparatus main body 1a in advance. When taking out the second process cartridge B, it can be taken out with the first process cartridge A loaded. The attaching / detaching direction of the second process cartridge B is also the direction of the arrow 23 in FIG.
[0024]
As described above, in the developing device 5 , the second process cartridge B has two spaces: a hopper 5a that stores toner to be supplied for development and a waste toner storage portion 5c that stores waste toner collected by the cleaning device 7. These two spaces are partitioned by a wall 5d so that the toners inside them are not mixed with each other. The waste toner container 5c and the cleaning device 7 are connected by a pipe 25. Waste toner pushed into the pipe 25 by the screw 24 inside the cleaning device 7 passes through the pipe 25 to the waste toner container 5c. Stored.
[0025]
The pipe 25 is provided with a separation device that separates waste toner being conveyed into recyclable toner and impossible toner.
[0026]
FIG. 4 is an exploded cross-sectional view of the tip portion for attaching the pipe 25 from the cleaning device 7 to the developing device 5 and the waste toner storage portion 5c, and FIG. 5 is an assembled cross-sectional view of the same portion. These drawings show the disassembled and coupled state of the pipe 25 and the second process cartridge B from the cleaning device 7 at the time of attachment / detachment.
[0027]
As already described, the waste toner pushed into the pipe 25 by the screw 24 inside the cleaning device 7 is sent to the developing device 5 side through the pipe 25. FIG. 4 and FIG. as shown, the pipe 25, the waste toner having been sent, and that recyclable toner having a small particle size, in the unsuitable toner recycling or accidentally agglomerated or not mixed paper dust separation A separating device is provided. This separation device passes the mesh 26 (filter) over the mesh 26 before the waste toner sent from the cleaning device 7 to the waste toner storage portion 5c through the pipe 25 is sent to the waste toner storage portion 5c. Only small toner is passed through the waste toner container 5c without passing large toner through the toner 26 , and the waste toner is separated as described above. And each of the toner separated is conveyed by the screw 27, unsuitable waste toner recycling carried to the waste toner accommodating portion 5c, a recyclable particle size toner is you carry into the hopper 5 a. The screw 27 is rotated by transmitting a driving force through a gear train 30 from a gear (not shown) on the apparatus main body 1a side. Note the separation device of the present embodiment, a good maintenance for the pipe 25 having a mesh 26 and the developing unit 5 can be exchanged to one cord. Further, it is possible to prevent the toner from dropping when the waste toner path is attached to and detached from the developing device 5.
[0028]
In the figure, reference numeral 28 denotes a cap. The cap 28 opens and closes the opening 25a at the tip of the pipe 25 in accordance with the attachment / detachment of the second process cartridge B. Usually, the biasing member 29 is biased in the distal direction. The tip of the cap 28 protrudes from the tip of the pipe 25. When the second process cartridge B is mounted, the outer wall surface of the second process cartridge B pushes the cap 28, and the opening 25a of the pipe 25 and the opening 28a of the cap 28 And the opening 25a at the tip of the pipe 25 is opened. This mechanism is also provided on the developing side and performs the same operation.
[0029]
FIG. 6 is an enlarged sectional view showing the internal structure of the developing device 5. As shown in FIG. 1 and also in FIG. 1, inside the developing device 5, a hopper 5 a for toner used for development and a waste toner storage portion 5 c are partitioned by a flexible member 35. The flexible member 35 is made of, for example, a thin rubber sheet or a folded plastic sheet.
[0030]
As shown in FIG. 6, since the waste toner returned to the waste toner container 5c is small during the initial use of the second process cartridge B, the space volume is very small or almost none. When the process cartridge B is used and development is performed, the toner stored in the hopper 5a is reduced, while the waste toner storage portion 5c into which the waste toner is fed is provided with a flexible member 35 as shown in FIG. It expands while expanding (the volume of the hopper 5a decreases).
[0031]
In other words, the developing toner storage hopper 5a and the waste toner storage space 5c are expanded and contracted, so to speak, in a balanced manner depending on the amount of the development toner and waste toner stored. For this reason, it is not necessary to secure the hopper 5a for storing the developing toner and the space 5c for storing the waste toner in advance. This makes it possible to reduce the size of the second process cartridge B as much as possible. This makes it possible to reduce not only the developing device and the process cartridge but also the main body of the image forming apparatus.
[0032]
【The invention's effect】
As described above, the developing device according to the present invention can collect waste toner at the same time when the developing device is replaced. Therefore, maintenance is easy, and it is not necessary to provide a separate waste toner member, so that the cost is low. , are possible long life for recyclable waste toner, environment as the Do Ri friendly, good maintainability, not only attained an extended service life, the time of attachment and detachment of the developing unit and the waste toner path toner Furthermore prevented fallen, cost, also excellent as the Do Rutotomoni life, Ru prevent toner off of mounting and dismounting of the waste toner path and the developing device 5.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a main part of a copying apparatus as an embodiment of an image forming apparatus according to the present invention.
2 is a perspective view showing a detachable relationship between the apparatus main body of FIG. 1 and a first process cartridge. FIG.
FIG. 3 is a schematic diagram showing an internal structure of the developing device.
FIG. 4 is an exploded cross-sectional view of a tip portion of a pipe from a cleaning device and a waste toner storage unit.
FIG. 5 is an assembled cross-sectional view of the same part.
FIG. 6 is an enlarged cross-sectional view showing the internal structure of the developing device.
FIG. 7 is an enlarged cross-sectional view showing the internal structure of the developing device in use.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Copying apparatus 1a Copying apparatus main body 2 Photosensitive drum 3 Corona discharge device 4 Short focus optical element array 5 Developing device 5a Hopper 5b Rotating body 5c Waste toner container 5d Wall 6 Transfer corona discharge device 7 Cleaning device 8 Housing 9, 20, 21 Guide rail 10 Document base 11 Lamp 12 Transfer material supply tray 13 Transport roller 14 Timing roller 15 Separating member 16 Movement path 17 Fixing device 18 Discharge roller 19 Discharge tray 22 Front door 24 Screw 25 Pipe 25a Opening at the tip of the pipe 26 mesh 27 screw 28 cap 28a cap opening 29 biasing member 30 gear train A first process cartridge B second process cartridge 35 flexible member

Claims (5)

In an image forming apparatus including a developing device that develops an electrostatic latent image on an electrophotographic photosensitive member, the developing device may recycle waste toner removed by a cleaning device provided separately from the developing device. A toner container that receives usable toner, a waste toner container that receives toner that is not suitable for reuse, and a flexible wall that separates the toner container and the waste toner container. A separation device for separating the waste toner removed by the cleaning device into a reusable toner and a toner unsuitable for reuse in the middle of the waste toner transport path removed by the cleaning device; The separation path bisects the conveyance path, one to a toner storage unit that receives reusable toner out of waste toner, and the other to a waste toner storage unit that receives toner unsuitable for reuse. The waste toner can be reused at the leading end of the transport path or in the vicinity of the leading end when the toner accommodating portion and the waste toner accommodating portion are attached to the toner accommodating portion. An image forming apparatus, comprising: an opening unit that feeds toner that is inappropriate for reuse into the housing unit.   2. The image forming apparatus according to claim 1, wherein the cleaning device is integrally supported by a casing together with the electrophotographic photosensitive member to constitute a first process cartridge, and the developing device is separated from the first process cartridge. A second process cartridge that is detachable independently of the first process cartridge, and when the both process cartridges are mounted on the image forming apparatus main body, the opening means opens and can be reused; waste toner; Can be received in the toner storage unit and the waste toner storage unit.   3. The image forming apparatus according to claim 2, wherein a cap having an opening is provided at a leading end of the transport path, and the opening of the cap closes the leading end of the transport path on the first process cartridge side or in the vicinity of the leading end according to the attachment / detachment of the process cartridge. An image forming apparatus that opens and closes an opening.   4. The image forming apparatus according to claim 3, wherein the opening of the cap is biased so as to be closed by a biasing member.   5. The image forming apparatus according to claim 3, wherein a protrusion is provided at a tip of the cap, and the protrusion is formed on an outer wall surface of the second process cartridge when the second process cartridge is attached to the first process cartridge. An image forming apparatus, wherein the image forming apparatus is pressed to open an opening of the conveyance path.

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