JP2001249543A - Electrophotographic image forming device, process cartridge and developing device used therein and toner recycling method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make toner carrying efficiency high by eliminating need for pushing up recovered toner as much as possible to a toner storage part against gravity, to reduce cost by shortening a recovered toner carrying path and reducing the number of parts and to drive a recovered toner carrying member naturally by shortening the recovered toner carrying path and simplifying the driving of the recovered toner carrying member. SOLUTION: This electrophotographic image forming device equipped with a toner recycling device 36 to restore the recovered toner from a cleaning device 14 to a developing device 12 is provided with a returning port 68 to return the recovered toner recovered by the device 36 to a middle position in the gravity direction of the toner storage part 21 in the device 12, that is, to a lower position in the gravity direction than the upper surface of the toner obtained when the storage part 21 is full of the toner.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an image forming apparatus such as a copying machine, a printer, a facsimile, or a multifunction peripheral thereof. In particular, of these, electrophotographic processes such as charging, writing, development, transfer, and cleaning are repeated to sequentially form toner images on the image bearing member, and the toner images are sequentially transferred, and finally a recording medium such as paper. The present invention relates to an electrophotographic image forming apparatus for performing recording.

Further, the present invention relates to a process cartridge used in such an electrophotographic image forming apparatus and having some functions of an electrophotographic process together with an image carrier. Further, the present invention also relates to a developing device for developing an electrostatic latent image on an image carrier, which is used in such an electrophotographic image forming apparatus. Further, the present invention relates to a toner recycling method for collecting and reusing toner not contributing to development in such an electrophotographic image forming apparatus.

[0003]

2. Description of the Related Art Today, from the viewpoint of effective use of resources and protection of the global environment, an electrophotographic image forming apparatus replaces toner that has not contributed to development among toner adhered to an image carrier.
Importance has been given to toner recycling, which is collected from a cleaning device or a transfer device and reused for development, and is actually performed.

Conventionally, in an image forming apparatus using a one-component developer containing only toner, for example, as shown in FIG. 20, the transfer residual toner on the photosensitive member 1 is scraped off by a cleaning blade 3 of a cleaning device 2, and the scraping is performed. The dropped toner is conveyed by the rotation of the coiled recovery toner conveying member 4, carried through the pipe 5 to the developing device 6, dropped from above, and returned to the toner storage section of the developing device 6 (for example, Japanese Patent Laid-Open No. 8-44171).

In a conventional image forming apparatus using a two-component developer composed of a toner and a carrier, for example, FIG.
As shown in FIG. 9, the transfer residual toner on the photoreceptor 1 is scraped off by the cleaning blade 3 of the cleaning device 2, and the scraped-off toner is transported by the rotation of the coil-shaped recovered toner transporting member 4, and To the developing device 6, dropped from above, returned to the toner storage section 7 of the developing device 6, and reused for development again.

[0006]

However, such a conventional image forming apparatus has the following problems.
1) In the image forming apparatus in which the cleaning device 2 and the developing device 6 are disposed on the left and right sides of the photoconductor 1 as in the above-described conventional example, the collected toner must be pushed up to the toner storage section 7 against the gravity. In such a case, the transport path of the collected toner becomes upward and longer, and the toner transport efficiency is reduced.

2) Since the collected toner is pushed up to the toner storage section 7 and dropped, the conveying path of the collected toner is lengthened, the number of parts is increased, and the cost is increased.

[0010] 3) The transport path of the recovered toner becomes longer, and the driving of the recovered toner transporting member 4 becomes complicated, which causes difficulty.

Accordingly, a first object of the present invention is to eliminate the need to push the collected toner up to the toner storage section against the gravity as much as possible, and to improve the toner transfer efficiency,
The number of parts is reduced by shortening the transport path of the collected toner,
An object of the present invention is to reduce the cost and simplify the driving of the collected toner conveying member by shortening the conveying path of the collected toner so that the collected toner conveying member can be driven without difficulty.

A second object is to achieve the first object by forcibly pushing the collected toner into the toner in the toner storage section with a strong conveying force.

A third object of the present invention is to achieve the first object by causing the collected toner to enter the toner in the toner storage section and return the collected toner by the collected toner conveying member.

A fourth object of the present invention is to achieve the first object by reducing the return resistance of the collected toner so that the collected toner can be easily returned into the toner storage section.

A fifth object is to return the collected toner to the toner storage unit without unevenness.

A sixth object is to reduce the size of the main body of the image forming apparatus and to facilitate handling during maintenance such as jam clearance, component replacement and repair.

A seventh object is to improve the economical efficiency by dividing the process cartridge so that it can be replaced.

[0016]

Accordingly, the present invention provides
In order to achieve the first object, in an electrophotographic image forming apparatus provided with a toner recycling device for returning collected toner to a developing device, the toner recycling device is provided at an intermediate position in a gravity direction of a toner storage unit provided in the developing device. A return port for returning the returned collected toner is provided.

According to a second aspect of the present invention, in order to achieve the second object, in the electrophotographic image forming apparatus according to the first aspect, the driving force of the toner stirring member in the toner storage is transmitted. It is characterized by driving a collected toner conveying member of a toner recycling device.

The invention according to claim 3 is the same as the second invention.
In order to achieve the above object, in the electrophotographic image forming apparatus according to the present invention, the rotating shaft of the toner stirring member and the rotating shaft of the collected toner conveying member are integrally formed.

The invention according to claim 4 is the same as the second invention.
In order to achieve the above object, the electrophotographic image forming apparatus according to claim 1, wherein the collected toner conveying member of the toner recycling apparatus is formed so as to be gradually sharpened toward the toner storage section. I do.

According to a fifth aspect of the present invention, in order to achieve the third object, in the electrophotographic image forming apparatus according to the first aspect, the collected toner conveying member of the toner recycling device is inserted into the toner storage section. Is characterized by the following.

According to a sixth aspect of the present invention, there is provided an electrophotographic image forming apparatus according to the fifth aspect, wherein the collected toner conveying member is provided with a toner agitating member in a toner storage section. It extends to the inside of the toner storage along the rotation axis.

The invention according to claim 7 is the same as the fifth invention.
In order to achieve the above object, in the electrophotographic image forming apparatus according to claim 6, the toner conveying direction of the collected toner conveying member in the toner storage unit is reversed from the return port to the middle and from the middle to the back. It is characterized by that.

The invention according to claim 8 is the same as the fifth invention.
In order to achieve the above object, in the electrophotographic image forming apparatus according to claim 6, the recovered toner conveying member is extended through the rotation shaft of the toner stirring member in the toner storage unit, and the toner discharge hole is formed in the rotation shaft. Is provided.

According to a ninth aspect of the present invention, in order to achieve the fourth object, in the electrophotographic image forming apparatus according to the first aspect, an eave is provided above the return port so as to protrude into the toner storage section. It is characterized by that.

According to a tenth aspect of the present invention, in order to attain the fourth object, in the electrophotographic image forming apparatus according to the first aspect, the cylindrical member is inserted into the toner storing portion from the edge of the return opening. It is characterized by being provided so as to protrude.

According to an eleventh aspect of the present invention, in the electrophotographic image forming apparatus according to the tenth aspect, the cylindrical member is formed to be tapered in order to achieve the second and fourth objects. Features.

According to a twelfth aspect of the present invention, in order to achieve the fourth object, in the electrophotographic image forming apparatus according to the first aspect, a case in which a return opening is formed is provided on the return opening. It is characterized by providing a stepped portion to cover.

According to a thirteenth aspect of the present invention, in order to attain the fourth object, in the electrophotographic image forming apparatus according to the first aspect, the toner in the toner storage section is provided at the return port with the toner recycling device. And a backflow preventing member for preventing backflow to the backflow is provided.

According to a fourteenth aspect of the present invention, in order to achieve the fourth object, the electrophotographic image forming apparatus according to the first aspect, wherein the toner agitating member in the toner storage unit is returned to the rotating shaft. A blade for removing toner near the mouth is provided.

According to a fifteenth aspect of the present invention, in order to attain the fourth object, in the electrophotographic image forming apparatus according to the first aspect, the toner in the vicinity of the return port is moved deep into the toner storage unit. And a toner feeding member for conveying
It is characterized by the following.

According to a sixteenth aspect of the present invention, in order to achieve the first object, in a process cartridge of an electrophotographic image forming apparatus, toner is attached to develop an electrostatic latent image on an image carrier. A developing device, and a toner recycling device for returning the collected toner to the developing device, and a return port for returning the collected toner returned by the toner recycling device is provided at an intermediate position in a gravity direction of a toner storage unit provided in the developing device. It is characterized by that.

According to a seventeenth aspect of the present invention, there is provided a process cartridge for an electrophotographic image forming apparatus according to the sixteenth aspect, wherein an image carrier is provided.
A cleaning device for scraping off transfer residual toner from the image carrier, a toner recycling device, and a developing device.

According to an eighteenth aspect of the present invention, in order to achieve the seventh object, in the process cartridge of the electrophotographic image forming apparatus according to the sixteenth aspect, the toner recycling device includes a first portion and a second portion. And can be divided into
It is characterized by comprising a first cartridge portion provided with an image carrier and a cleaning device together with the first portion, and a second cartridge portion provided with a developing device together with the second portion.

According to a nineteenth aspect of the present invention, in order to achieve the first object, in a developing device of an electrophotographic image forming apparatus, an electrostatic latent image on an image carrier is developed by attaching toner. A developing unit, and a toner storage unit for storing toner to be supplied to the developing unit, and a return port for returning the collected toner returned by the toner recycling device is provided at an intermediate position in the gravity direction of the toner storage unit. It is characterized by the following.

According to a twentieth aspect of the present invention, in order to achieve the first object, in a toner recycling method for an electrophotographic image forming apparatus, toner not contributing to development is collected and returned by a toner recycling apparatus. The toner storage unit provided in the developing device is returned from a return port provided at an intermediate position in the direction of gravity and reused in the developing device.

[0036]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a schematic configuration of a main part of an electrophotographic image forming apparatus according to the present invention.

Reference numeral 10 in the figure denotes a drum-shaped photosensitive member serving as an image carrier. On the upper side of the photoconductor 10, a roller-type charging device 11 is provided so as to be opposed to and parallel to the photoconductor 10. The developing device 12 is provided on the right side of the photoreceptor 10 in the drawing, the transfer device 13 is provided below, and the cleaning device 14 is provided on the left side of the photoreceptor 10 in order from the charging device 11 in the rotating direction of the photoreceptor 10.

The writing device 15 is arranged on the charging device 11. Further, a fixing device 16 is provided on the left side of the cleaning device 14.

Then, as the photosensitive member 10 rotates, the surface of the photosensitive member 10 is uniformly charged by the charging device 11, and writing is performed by irradiating the writing light L with the writing device 15.
An electrostatic latent image is formed on the surface of the No. 0.

Subsequently, when the photosensitive member 10 is further rotated, in the case of a negative / positive state, toner is attached to the latent image portion by the developing device 12 to form a visible image, and a toner image is formed on the photosensitive member 10. Thereafter, the transfer device 13 transfers the toner image on the photoconductor 10 to a recording medium 18 such as a sheet that has been conveyed to the lower side of the photoconductor 10 at a timing by the rest roller 17.

The surface of the photoreceptor 10 after the image transfer is cleaned by removing the residual toner by the cleaning device 14, and thereafter, for example, is discharged by a discharging lamp (not shown) to prepare for the next image formation starting from charging.

On the other hand, the recording medium 18 after the image transfer is conveyed to the fixing device 16, where the transferred image is fixed by the fixing device 16, and then discharged outside the image forming apparatus main body by a discharge roller (not shown). Stacked on the output tray.

The developing device 12 used in the image forming apparatus of this embodiment is a one-component developing device, and a developing unit 20 for developing an electrostatic latent image on the photoreceptor 10 by attaching toner, and a developing unit 20 Storage unit 2 for storing toner to be supplied to the printer
1 is provided. The developing unit 20 is provided with a developing roller 22, a thinning blade 23 for pressing the tip against the developing roller 22, and the like.
The toner storage unit 21 has a toner stirring member (agitator) 24 that sends the stored toner to the developing unit 20 while stirring the toner.
And so on.

The transfer device 13 wraps the transfer belt 26 between a driving roller 27 and a driven roller 28,
6 is provided with a coil-shaped recovered toner transport member 30 which is pressed against the tip of the cleaning blade 29 and transports the toner scraped off by the cleaning blade 29.

In this example, the cleaning device 14 supports a blade-like cleaning member 33 via a holder 32, and presses the tip of the cleaning member 33 against the surface of the photoreceptor 10 to remove the collected toner. And a screw-shaped collected toner conveying member 34 that conveys in the direction.

In the illustrated example, the photoconductor 10, the charging device 11, the developing device 12, the cleaning device 12 A process cartridge 40 is formed by the toner recycling device 14 and a toner recycling device 36 described later, as shown in FIG.

The process cartridge 40
Describes a first embodiment in which the toner recycling device 36 is divided into a first portion 37 and a second portion 38 as described later, and the first portion 37 includes the photoconductor 10, the charging device 11, and the cleaning device 14 together with the first portion 37. Cartridge part 41
And a second unit 38 including the developing device 13 together with the second portion 38.
And the cartridge part 42 of the above.

As shown in FIG. 3, the toner recycling device 36 has a first side on one side of the process cartridge 40.
The cleaning device 14 and the developing device 12 are connected to each other, and the collected toner is returned from the cleaning device 14 to the developing device 12.

That is, the above-mentioned collected toner conveying member 34 of the cleaning device 14 has one end protruding from the cartridge case 44 of the first cartridge portion 41, and has a gear 45 fixed to the front end as shown in FIG. On the other hand, the other end of the collected toner conveying member 34 protrudes from the cylindrical portion 46 of the cartridge case 44 as shown in FIG. 3, and has a roller portion 48 having a pin 47 at the end as shown in FIG. .

Then, one side of the belt-shaped collected toner conveying member 50 is hung on the roller portion 48, and the pin 47 is inserted into the long hole 51 of the collected toner conveying member 50. Blades 52 are provided at regular intervals on the outer periphery of the collected toner conveying member 50, and the other side is hung on a roller portion 54 of a rotating shaft 53.

As shown in FIG. 3, the collected toner conveying member 50 is housed in a conveying path lower case 56 together with the roller portion 48 and the rotating shaft 53. The transport path lower case 56 is
The first cartridge portion 41 forms a main part of the first portion 37 of the toner recycling device 36, and is connected to the above-described cylindrical portion 46 and the semi-cylindrical lower connecting portion 57 to be integrated with the cartridge case 44. It is formed by molding.

In the longitudinal direction of the lower case 56, the lower case 58 is connected linearly so as to be separable. The lower conveying path case 58 is provided with the second cartridge portion 4.
2, the main portion of the second portion 38 of the toner recycling device 36 is formed, and is connected to the lower cartridge case 60 of the second cartridge portion 42 by being connected with the lower connecting portion 59 of a semi-cylindrical shape. Do it.

A belt-like collected toner conveying member 62 having blades 61 provided at regular intervals on the outer periphery is similarly placed in the lower conveying path case 58. The collected toner conveying member 62 hangs one side of the roller portion of the rotating shaft 63,
The other side is hung on the roller portion 64, and the roller portion 6 shown in FIG.
The pin 65 of the recovery toner conveying member 62 has the pin 65
Put in 6. The roller portion 64 is provided at the base end of the screw-shaped collected toner conveying member 67.

As shown in FIG. 3, the collected toner conveying member 6
7 is a lower cartridge case 60 through the lower connecting portion 59.
, And the leading end is allowed to enter the toner storage section 21 from the return port 68 through the backflow prevention member 69.

The backflow preventing member 69 is, as shown in FIG.
For example, it is formed in a conical shape using a rubber material, is provided with a slit 70 on the distal end side and is opened as shown in the figure when the collected toner conveying member 67 is passed, and the base end 71 is bonded to the rim of the return opening 68. And so on.

By the way, the collected toner conveying member 6 described above
In the illustrated example, the rotating shaft 73 is formed integrally and continuously with the rotating shaft 74 of the toner stirring member 24 described above. The other end of the rotation shaft 74 of the toner stirring member 24 protrudes from the lower cartridge case 60, and a gear 75 is fixed to the front end as shown in FIG.

Then, the upper cartridge case (not shown) of the second cartridge portion 42 is put on the lower cartridge case 60, and the upper cartridge case and the upper connecting portion integrated with the upper cartridge case are respectively connected to the lower cartridge case 60. , The lower connecting portion 59, the lower case 58 of the conveying path,
And covers the lower connecting portion 57 of the first cartridge portion 41 and the upper case 56 of the lower conveying path.

When the process cartridge 40 thus manufactured is incorporated in the image forming apparatus main body, the gear 45 (see FIG. 4) on the collected toner conveying member 34 meshes with a drive gear (not shown) on the apparatus main body side. The gear 75 on the rotation shaft 74 of the toner stirring member 24 is the same as that shown in FIG.
The gear 77 of the drive source 76 provided on the apparatus main body side as shown in FIG.
Mesh with.

Thus, as can be seen from FIG. 1, in the electrophotographic image forming apparatus provided with the toner recycling device 36 for returning the collected toner from the cleaning device 14 to the developing device 12, the toner storage portion 21 provided in the developing device 12
Return port 6 for returning the collected toner returned by the toner recycling device 36 to the intermediate position in the gravity direction of the toner storage unit 21, that is, to a position below the upper surface of the toner when the toner storage unit 21 is full in the gravity direction.
8 is provided.

As can be seen from FIG. 2, the process cartridge 40 of such an electrophotographic image forming apparatus is
The developing device 12 includes a developing device 12 that adheres toner to develop the electrostatic latent image on the photoconductor 10, and a toner recycling device 36 that returns collected toner to the developing device 12. A return port 68 for returning the collected toner returned by the toner recycling device 36 is provided at an intermediate position in the gravity direction.

When the image forming apparatus is started to be used, a driving force is transmitted from a driving source on the apparatus main body side via a gear 45, and the collected toner conveying member 34 in the cleaning apparatus 14 is rotated to recycle the toner. The collected toner conveying member 50 of the device 36 also rotates.

The drive source 76 on the apparatus main body side sends the gear 7
Driving force is transmitted through the engagement of 7.75 to rotate the toner agitating member 24 in the toner storage unit 21 and transmit the driving force to the collected toner conveying member 67 integrated with the toner agitating member 24 to rotate. Then, the collected toner conveying member 62 of the toner recycling device 36 also rotates.

The untransferred toner scraped off by the cleaning member 33 of the cleaning device 14 is conveyed in the axial direction by the collected toner conveying member 34 to be collected, and is fed into the toner recycling device 36. The blades 52 and the blades 61 of the collected toner conveying member 62 convey and scrape each other, then convey and return by the collected toner conveying member 67, return to the toner storage unit 21 from the return port 68, and reuse the developing device 12. I do.

Thus, in the illustrated example, the return port 68 for the collected toner is provided at the intermediate position in the gravitational direction of the toner storage unit 21. Make it smaller
The degree of pushing the collected toner up to the toner storage unit 21 against the gravity can be reduced, and the toner transfer efficiency can be increased. Further, the conveying path of the collected toner is shortened to reduce the number of parts and cost can be reduced. In addition, the conveying path of the collected toner is shortened to simplify the driving of the collected toner conveying members 50, 62, and 67. These collected toner conveying members can be driven without difficulty.

In the image forming apparatus as described above, the toner is filled in the toner storage section 21 at the start of use. For this reason, it is very difficult to return the recovered toner into the toner storage unit 21 from the return port 68 at the intermediate position in the gravity direction of the toner storage unit 21 due to the powder pressure of the toner.

Therefore, the toner storage unit 2 filled with toner
In order to facilitate the return of the collected toner during the operation, for example, 1) the return conveyance force of the collected toner is increased to force the collected toner into the toner. 2) The collected toner conveying member 67 is inserted into the toner storage section 21 so that the collected toner is returned into the toner. 3) It is difficult for the toner powder pressure in the toner storage unit 21 to be directly applied to the return port 68, thereby reducing the return resistance. 4) The toner near the return port 68 in the toner storage unit 21 is positively removed to reduce the return resistance.

As the method 1), for example, as shown in the above-described example, the toner stirring member 2 in the toner storage section 21 is used.
The driving force of No. 4 is transmitted to drive the collected toner conveying member 67 of the toner recycling device 36. Then, the cost is reduced without providing a dedicated driving source, the collected toner conveying member 67 is driven together with the driving of the toner stirring member 24, and the collected toner is forcibly stored in the toner storage unit 21 by the strong conveying force of the nearby driving source. Press it into the toner.

In the illustrated example, the rotating shaft 74 of the toner stirring member 24 and the rotating shaft 73 of the collected toner conveying member 67 are formed integrally, so that not only the number of parts is reduced but also the driving force of the toner stirring member 24 is reduced. Immediately recovered toner transport member 6
7, and the recovered toner conveying member 67 can be rotated with a stronger force without loss.

For example, as shown in FIG. 7, a screw-shaped collected toner conveying member 67 is formed with a taper toward the toner storage section 21 with a gradually decreasing diameter, and the toner conveying force is gradually increased by squeezing. You may make it.

As the method 2), for example, as shown in the above-described illustrated example, the collected toner conveying member 67 of the toner recycling device 36 is inserted into the toner storage section 21. Then, the collected toner enters the toner in the toner storage unit 21 and is returned by the collected toner conveying member 67.

For example, as shown in FIG. 8, when the collected toner conveying member 67 is inserted into the toner storage section 21 and is extended along the rotation shaft 74 of the toner stirring member 24 to the inside of the toner storage section 21, the collected toner is conveyed. The toner can be returned to the toner storage unit 21 without unevenness.

In order to provide the collected toner conveying member 67 along the rotating shaft 74 of the toner stirring member 24 to the inside of the toner storage section 21, the rotating shaft 74 itself is formed into a screw shape as shown in the drawing, and the collected toner is conveyed. The collected toner conveying member 67 may be formed as a conveying member 67, and a coil may be wound around the rotating shaft 74 so as to be coaxial with the rotating shaft 74. May be extended in parallel with the rotation shaft 74.

At this time, assuming that the toner conveying direction by the collected toner conveying member 67 in the toner storage section 21 is reversed from a from the return port 68 to the middle as shown in FIG. The collected toner can be returned evenly and evenly into the toner storage unit 21. In this case, reverse rotation is performed for a belt, and reverse winding is performed for a screw or coil.

As shown in FIG. 10, the collected toner conveying member 67 is connected to the toner stirring member 2 in the toner storage section 21.
4 and a toner discharge hole 80 is provided in the rotation shaft 74. And the rotating shaft 74
While conveying the collected toner through the inside, the toner discharge holes 8
The toner may be returned from 0 to the toner storage unit 21 and the collected toner may be uniformly returned to the toner storage unit 21 without unevenness.

At this time, if the distance between the toner discharge holes 80 decreases as the toner amount decreases and the hole diameter increases, the collected toner is evenly and evenly distributed in the toner storage unit 21. You can go back. Further, the collected toner conveying member 67 may be driven from the toner recycling device 36 side.

As a method 3), as shown in FIG. 11, for example, an eave 81 is attached to the return port 68 integrally with the case 100 as shown in FIG. 21 so as to protrude. And eaves 81
And the powder pressure of the toner in the toner storage unit 21 returns to the return port 6.
8 is hardly added to the vicinity, and the return resistance of the collected toner is reduced, so that the collected toner is easily returned into the toner storage unit 21.

Further, as shown in FIG. 12, the cylindrical member 82 such as a cylinder or a square cylinder is attached to the case 100 from the edge of the return port 68 as shown in FIG. It protrudes and is provided in the storage part 21. Similarly, it is difficult for the powder pressure of the toner in the toner storage unit 21 to be directly applied to the vicinity of the return port 68 by being blocked by the cylindrical member 82, and the return resistance of the collected toner is reduced to return the collected toner to the toner storage unit 21. Make cheaper.

When the cylindrical member 82 is tapered as shown in FIG. 13, for example, the toner conveying force is gradually increased by further squeezing out the toner, and the collected toner is forced into the toner in the toner storage section 21 with a strong conveying force. Can be pushed.

Further, as shown in FIG. 14, for example, a step portion 84 which covers the return port 68 is formed in the case 100 in which the return port 68 is formed. Then, the toner is blocked by the step portion 84 so that the powder pressure of the toner in the toner storage unit 21 is hardly applied to the vicinity of the return port 68, and the return resistance of the collected toner is reduced to return the collected toner to the toner storage unit 21. Make cheaper.

Further, as in the illustrated example described above, the return port 68 is provided with a backflow prevention member 69 for preventing the toner in the toner storage unit 21 from flowing back to the toner recycling device 36. Then, the return resistance of the collected toner can be reduced, and the collected toner can be returned to the toner storage unit 21 at a low price.

As a method 4), for example, as shown in FIG.
A blade 85 for removing the toner near the return port 68 is provided. Then, the return resistance of the recovered toner is reduced, and the recovered toner is returned into the toner storage unit 21 to be cheap.

Further, as shown in FIG. 16, for example, a screw-shaped toner feeding member 86 for conveying the toner in the vicinity of the return opening 68 to the inside of the toner storage section 21 is provided. Then, the toner in the vicinity of the return port 68 is sent in the direction indicated by the arrow in the drawing to be eliminated, so that the return resistance of the recovered toner is reduced, and the recovered toner is returned to the toner storage section 21 with ease.

Reference numeral 87 in FIG. 16 designates a gear provided coaxially with the toner feeding member 86 outside the case 60. When this process cartridge is mounted on the image forming apparatus main body, as shown in FIG. The gear 88 is engaged. Reference numeral 89 denotes a bracket which is attached to the case 60 and rotatably supports the toner feeding member 86.

In the example shown in FIG. 1 described above, the developing device 12 and the cleaning device 14
Has been described at the same height position,
The present invention can be similarly applied to a case where the developing device 12 is located at a position higher than the cleaning device 14, and the same effect is obtained.

In the above-described example, the case where the toner is collected from the cleaning device 14 has been described. However, the present invention is not limited to the case where toner not contributing to development is collected only from a cleaning device,
For example, in the example shown in FIG. 1, the case where the collected toner collected by the collected toner conveying member 30 from the transfer device 13 is returned to the developing device 12 for recycling is also included.

In addition, in a color image forming apparatus, a single color image formed on a photosensitive member is sequentially transferred to form a composite color image on an intermediate transfer member, and the color image is transferred to a recording medium such as paper. A color image is formed thereon. Even in such a color image forming apparatus, the transfer residual toner is scraped off from the intermediate transfer body by a cleaning device. However, the present invention includes a case where the toner scraped off from the intermediate transfer body is returned to the developing device 12 for recycling. And so on.

Further, in the illustrated example, the collected toner conveying members 34 and 67 are screw-shaped,
Although the case where 0.62 has a belt shape has been described, the collected toner conveying member for returning the collected toner may be a screw shape, a belt shape, or a coil shape.

In the example shown in FIG. 1 described above, the image forming apparatus having the one-component developing device 12 has been described. However, the present invention is not limited to, for example, FIGS.
The present invention can be similarly applied to an image forming apparatus having a two-component developing device 12 as shown in FIG.

The two-component developing device 12 includes a toner storage 21
A toner stirring member (agitator) 2 for storing toner inside
4, the toner is supplied to the stirring / conveying unit 92 by the rotation of the toner supply roller 91.
The magnetic brush is formed on a developing sleeve 95 accommodating a plurality of fixed magnets 94 by stirring the carrier with the carrier by the rotation of the paddle wheel 93 and forming a magnetic brush on the developing sleeve 95 accommodating a plurality of fixed magnets 94. Develop the upper electrostatic latent image.

In this image forming apparatus, the cleaning device 14 and the developing device 12 are connected to each other, and a toner recycling device 36 is provided. The collected toner is returned from the cleaning device 14 to the developing device 12. Then, similarly, the toner storage unit 2
A return port 68 for returning the collected toner returned by the toner recycle device 36 is provided at the middle position in the gravity direction of 1, ie, below the upper surface of the toner when the toner is full in the gravity direction.

In the examples shown in FIGS. 17 and 18 as well, the inclination of the conveying path of the collected toner is made smaller than that of pushing up the collected toner to the toner storage section 21 so that the collected toner is moved to the toner storage section 21 against gravity. The degree of pushing up can be reduced, and the toner transfer efficiency can be increased.

In the example shown in FIGS. 17 and 18, unlike the example shown in FIG. 1, the toner recycle device 36 is formed integrally as shown in FIG. 18 without being made divisible.

[0093]

As described above, according to the present invention, since the return port for the collected toner is provided at the intermediate position in the gravity direction of the toner storage section, the degree to which the collected toner is pushed up to the toner storage section against the gravity is reduced. Thus, it is possible to increase the toner transfer efficiency. In addition, the transport path of the collected toner can be shortened to reduce the number of parts, thereby reducing costs. It can be driven without difficulty.

According to the second aspect of the present invention, the driving force of the toner agitating member is transmitted to drive the collected toner conveying member. By driving the collected toner conveying member, the collected toner can be forcibly pushed into the toner in the toner storage unit with a strong conveying force from a nearby driving source.

According to the third aspect of the invention, since the rotating shaft of the toner stirring member and the rotating shaft of the collected toner conveying member are integrally formed, not only the number of parts is reduced but also the driving force of the toner stirring member. Is immediately transmitted to the collected toner conveying member, and the collected toner conveying member can be rotated with a stronger force without loss.

According to the fourth aspect of the present invention, since the collected toner conveying member is formed so as to be gradually sharpened toward the toner storage portion, the toner conveying force is gradually increased so as to squeeze out, and the collected toner is strongly conveyed. It can be forcibly pushed into the toner in the toner storage unit.

According to the fifth aspect of the present invention, since the collected toner conveying member is inserted into the toner storage section, the collected toner can be inserted into the toner in the toner storage section and returned by the collected toner conveying member.

According to the sixth aspect of the present invention, since the collected toner conveying member extends to the inside of the toner storage section along the rotation axis of the toner stirring member, the collected toner can be returned to the toner storage section without substantially unevenness. .

According to the seventh aspect of the present invention, the toner conveying direction of the collected toner conveying member in the toner storage section is reversed from the return port to the middle and from the middle to the back. It can be evenly and evenly returned inside the unit.

According to the eighth aspect of the present invention, the collected toner conveying member is extended through the rotation shaft of the toner stirring member in the toner storage section, and the rotation shaft is provided with a toner discharge hole. While transporting
Since the toner is returned from the toner discharge hole into the toner storage unit, the collected toner can be uniformly returned into the toner storage unit without unevenness.

According to the ninth aspect of the present invention, since the eaves are provided above the return opening so as to protrude into the toner storage portion, the powder pressure of the toner in the toner storage portion is not easily applied to the vicinity of the return opening by the eaves. In addition, the return resistance of the collected toner can be reduced, and the collected toner can be returned to the toner storage section at a low price.

According to the tenth aspect of the present invention, since the cylindrical member is provided so as to protrude into the toner storage portion from the rim of the return opening, the powder pressure of the toner in the toner storage portion is similarly blocked near the return opening by the cylindrical member. Therefore, it is possible to reduce the return resistance of the collected toner and reduce the amount of the collected toner returned into the toner storage unit.

According to the eleventh aspect of the present invention, since the cylindrical member is tapered, the toner conveying force is gradually increased so as to further squeeze out the toner, and the collected toner is forcibly moved with the strong conveying force. Can be pushed inside.

According to the twelfth aspect of the invention, since the step forming the return port is formed with a step covering the return port, the step is blocked by the step and the toner in the toner storage section is blocked. Powder pressure is less likely to be directly applied to the vicinity of the return port, and the return resistance of the recovered toner is reduced, so that the recovered toner can be returned to the toner storage section at a low price.

According to the thirteenth aspect of the present invention, since the return port is provided with the backflow preventing member for preventing the toner in the toner storage from flowing back to the toner recycling device,
The return resistance of the recovered toner can be reduced, and the recovered toner can be returned to the toner storage section at a low price.

According to the fourteenth aspect of the present invention, since the toner stirring member is provided with the blade for removing the toner near the return port, the return resistance of the recovered toner is reduced and the recovered toner is easily returned to the toner storage section. be able to.

According to the fifteenth aspect of the present invention, since the toner feeding member for transporting the toner near the return port to the inside of the toner storage unit is provided, the toner near the return port is excluded and the return resistance of the collected toner is reduced. , And the recovered toner can be returned to the toner storage section at low cost.

According to the sixteenth aspect of the present invention, in the process cartridge including the developing device and the toner recycling device, the return port of the recovered toner is provided at the intermediate position in the gravity direction of the toner storage unit provided in the developing device. Need not be pushed up to the toner storage portion against the gravity, and the toner transport efficiency can be improved. Also,
The number of parts is reduced by shortening the transport path of the collected toner,
It is possible to reduce the cost, simplify the driving of the collected toner conveying member by shortening the conveying path of the collected toner, and easily drive the collected toner conveying member.

According to the seventeenth aspect of the present invention, since the image carrier, the cleaning device, the toner recycling device, and the developing device are integrally provided, the size of the image forming apparatus main body can be reduced, and at the same time, the jam processing and component replacement can be performed. Handling during maintenance such as maintenance and repair can be facilitated.

According to the eighteenth aspect, in the process cartridge, the process cartridge can be divided into a first cartridge portion having a relatively long life and a second cartridge portion having a relatively short life. Can be individually exchanged, so that economy can be improved.

According to the nineteenth aspect of the present invention, in the developing device of the electrophotographic image forming apparatus, a developing unit and a toner storage unit are provided, and the toner storage unit is returned to an intermediate position in the gravity direction by the toner recycling device. Since the return port for returning the collected toner is provided, there is no need to push the collected toner up to the toner storage portion against the gravity, and the toner transport efficiency can be improved. In addition, the transport path of the collected toner can be shortened to reduce the number of parts and cost reduction. In addition, the transport path of the collected toner can be shortened to simplify the drive of the collected toner transport member, and the collected toner transport member can be reduced. It can be driven without difficulty.

According to the twentieth aspect, in the toner recycling method of the electrophotographic image forming apparatus, the toner not contributing to the development is collected, returned by the toner recycling apparatus, and stored in the toner storage unit provided in the developing apparatus. Since the toner is returned from the return port provided in the middle position in the direction of gravity and is reused in the developing device, similarly, it is not necessary to push up the collected toner to the toner storage section against the gravity, thereby improving the toner transport efficiency. it can. In addition, the transport path of the collected toner can be shortened to reduce the number of parts and cost reduction. In addition, the transport path of the collected toner can be shortened to simplify the drive of the collected toner transport member, and the collected toner transport member can be reduced. It can be driven without difficulty.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a main part of an electrophotographic image forming apparatus according to the present invention.

FIG. 2 is a schematic configuration diagram of a process cartridge used in the image forming apparatus.

FIG. 3 is a partial perspective view of the process cartridge with the upper cartridge case removed.

FIG. 4 is a partially exploded perspective view of a toner recycling device used in the process cartridge.

FIG. 5 is another partially exploded perspective view.

FIG. 6 is a perspective view of a backflow prevention member of the process cartridge.

FIG. 7 is a partial cross-sectional view illustrating a toner storage section of a process cartridge according to another embodiment of the present invention.

FIG. 8 is an explanatory cross-sectional view of a toner storage section of a process cartridge according to still another embodiment of the present invention.

FIG. 9 is an explanatory cross-sectional view of a toner storage section of a process cartridge, showing still another example of the present invention.

FIG. 10 is an explanatory cross-sectional view of a toner storage section of a process cartridge according to still another embodiment of the present invention.

FIG. 11 is a partial cross-sectional view illustrating a toner storage portion of a process cartridge according to still another embodiment of the present invention.

FIG. 12 is a partial cross-sectional view illustrating a toner storage section of a process cartridge according to still another embodiment of the present invention.

FIG. 13 is a partial cross-sectional view illustrating a toner storage portion of a process cartridge according to still another embodiment of the present invention.

FIG. 14 is an explanatory partial cross-sectional view of a toner storage section of a process cartridge according to still another embodiment of the present invention.

FIG. 15 is an explanatory partial cross-sectional view of a toner storage section of a process cartridge, showing still another example of the present invention.

FIG. 16 is an explanatory partial cross-sectional view of a toner storage section of a process cartridge according to still another embodiment of the present invention.

FIG. 17 is a schematic configuration diagram of a main part of an image forming apparatus, showing still another example of the present invention.

FIG. 18 is a partial perspective view of a process cartridge used in the image forming apparatus.

FIG. 19 is a schematic configuration diagram of a main part of a conventional image forming apparatus using a one-component developer.

FIG. 20 is a schematic configuration diagram of a main part of a conventional image forming apparatus using a two-component developer.

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 photoconductor (image carrier) 12 developing device 13 transfer device 14 cleaning device 20 developing unit 21 toner storage unit 24 toner stirring member 36 toner recycling device 37 first portion of toner recycling device 38 second portion of toner recycling device 40 Process Cartridge 41 First Cartridge Portion 42 Second Cartridge Portion 67 Collected Toner Transport Member 68 Return Port 69 Backflow Prevention Member 73 Rotary Axis of Collected Toner Transport Member 74 Rotary Axis of Toner Stirring Member 80 Toner Release Hole 81 Eave 82 Tube Member 84 Step portion 85 Blade 86 Toner feed member 100 Case

Claims (20)

[Claims] 1. An electrophotographic image forming apparatus comprising a toner recycling device for returning collected toner to a developing device, wherein the toner recycling device returns the collected toner to an intermediate position in a gravity direction of a toner storage unit provided in the developing device. An electrophotographic image forming apparatus provided with a return port for returning toner. 2. The electrophotographic image forming apparatus according to claim 1, wherein a driving force of a toner stirring member in the toner storage unit is transmitted to drive a collected toner conveying member of the toner recycling device. 3. The electrophotographic image forming apparatus according to claim 2, wherein a rotation shaft of said toner stirring member and a rotation shaft of said collected toner conveying member are formed integrally. 4. The electrophotographic image forming apparatus according to claim 1, wherein the collected toner conveying member of the toner recycling device is formed so as to be gradually sharpened toward the toner storage unit. 5. The toner recycling device according to claim 5, wherein a collected toner conveying member of the toner recycling device is inserted into the toner storage unit.
The electrophotographic image forming apparatus according to claim 1. 6. The electrophotographic image forming apparatus according to claim 5, wherein the recovered toner conveying member extends to a depth inside the toner storage unit along a rotation axis of a toner stirring member in the toner storage unit. 7. The electrophotographic image forming apparatus according to claim 6, wherein a toner conveying direction of the collected toner conveying member in the toner storage section is reversed from the return port to the middle and from the middle to the back. apparatus. 8. The electrophotographic image according to claim 6, wherein the collected toner conveying member is extended through a rotation shaft of a toner stirring member in the toner storage portion, and a toner discharge hole is provided in the rotation shaft. Forming equipment. 9. The electrophotographic image forming apparatus according to claim 1, wherein an eave is provided above the return port so as to protrude into the toner storage unit. 10. The electrophotographic image forming apparatus according to claim 1, wherein a cylindrical member is provided so as to protrude into the toner storage section from an edge of the return port. 11. An electrophotographic image forming apparatus according to claim 10, wherein said cylindrical member is formed to be tapered. 12. The electrophotographic image forming apparatus according to claim 1, wherein the case forming the return opening is provided with a stepped portion covering the return opening. 13. The electrophotographic image forming apparatus according to claim 1, wherein the return port is provided with a backflow preventing member for preventing the toner in the toner storage unit from flowing back to the toner recycling device. 14. The electrophotographic image forming apparatus according to claim 1, wherein a blade for removing toner near the return port is provided on a rotation shaft of a toner stirring member in the toner storage unit. 15. The electrophotographic image forming apparatus according to claim 1, further comprising a toner feeding member for conveying the toner near the return port to the inside of the toner storage unit. 16. A toner storage unit provided in the developing device, comprising: a developing device for applying a toner to develop an electrostatic latent image on an image carrier; and a toner recycling device for returning collected toner to the developing device. A process cartridge for an electrophotographic image forming apparatus, wherein a return port for returning the collected toner returned by the toner recycling device is provided at an intermediate position in the gravity direction of the image forming apparatus. 17. An image forming apparatus comprising: the image carrier; a cleaning device for scraping off transfer residual toner from the image carrier; the toner recycling device; and the developing device.
A process cartridge for the electrophotographic image forming apparatus according to claim 16. 18. The apparatus according to claim 18, wherein the toner recycling device is divided into a first portion and a second portion, and a first cartridge portion including the image carrier and the cleaning device together with the first portion; 17. The process cartridge for an electrophotographic image forming apparatus according to claim 16, comprising a second cartridge part including the developing device together with a second cartridge part. 19. A developing unit for applying toner to develop an electrostatic latent image on an image carrier, and a toner storage unit for storing toner to be supplied to the developing unit, wherein the toner storage unit has a gravity direction. A developing device for an electrophotographic image forming apparatus, wherein a return port for returning the collected toner returned by the toner recycling device is provided at an intermediate position. 20. Recovering toner not contributing to the development, returning it by a toner recycling device, returning it from a return port provided at a middle position in the direction of gravity of a toner storage unit provided in the developing device, and reusing the toner in the developing device. A toner recycling method for an electrophotographic image forming apparatus.