JP3091785B2 - Image forming apparatus and process cartridge thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

(Table of Contents) Industrial Application Field Conventional Technology (FIGS. 7 and 8) Problems to be Solved by the Invention Means for Solving the Problems (FIG. 1) Action Embodiment (a) Description of Image Forming Apparatus (FIGS. 2 and 3) (b) Description of the process cartridge (FIGS. 4 and 6) (c) Description of another embodiment Effect of the Invention

[0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus and a process cartridge for storing toner removed by a cleaner in an image forming drum in an electrophotographic apparatus or the like.

Image forming apparatuses, such as electrophotographic apparatuses and electrostatic recording apparatuses, which form an electrostatic latent image and develop it to form a visible image are widely used in printing apparatuses, copiers, facsimile machines and the like. There is a demand for downsizing and easy maintenance.

In order to meet this demand, in an apparatus using an inexpensive organic photoreceptor, since the durability of the organic photoreceptor is low, the photosensitive drum, the cleaner, and the pre-charger are formed as an integral cartridge to facilitate replacement. .

In such a cartridge, the space inside the photosensitive drum is used to accommodate the waste toner removed by the cleaner without increasing the size of the cartridge, and the inside of the photosensitive drum is used as a storage tank for waste toner. A method of storing waste toner in a drum has been adopted.

[0006] In such a process cartridge, it is required that the waste toner is stably removed until the warranty life of the cartridge, and that when the waste toner tank becomes full, the apparatus can recognize this.

[0007]

2. Description of the Related Art FIG. 7 is an explanatory diagram (part 1) of the prior art, and FIG. 8 is an explanatory diagram (part 2) of the prior art.

As shown in FIG. 7A, in the electrophotographic apparatus, a rotating photosensitive drum 10 is pre-charged by a pre-charger 12, a light image is written by an optical unit 11, and an image is formed into an electrostatic latent image. The toner image is formed on a sheet (sheet) PP by a transfer unit 13 to obtain a toner image on the sheet PP. The remaining toner is removed by the cleaning blade 140 of the cleaner 14 so that the next image can be formed.

To use the inside of the photosensitive drum 10 as a waste toner tank, a cleaner 14 is integrated, and the cleaner 14 is provided with a discharge screw 141 for discharging the waste toner.

Conventionally, as shown in FIGS. 7B and 8A, a connecting screw 141a and a connecting screw 141a for guiding the toner discharged by the discharging screw 141 to the side of the cartridge 4 to the entrance of the photosensitive drum 10. In some cases, an introduction screw 41 for feeding the toner guided in 141a into the photosensitive drum 10 is provided to form a U-shaped waste toner conveyance path.

As another conventional example, as shown in FIG. 8B, there is also provided a discharge / introduction screw 141b integrally formed with a discharge / connection / introduction screw.

[0012]

However, the prior art has the following problems. Since the transport path from the cleaning blade 140 of the cleaner 14 to the photosensitive drum 10 is entirely constituted by a transport mechanism, if a part of the transport path is clogged, the transport mechanism is immediately destroyed.

Since the U-shaped conveyance path is conveyed while being pushed by a screw one direction at a time, the density of the waste toner increases toward the end of one path, and clogging tends to occur.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide an image forming apparatus and a process cartridge for the same which can be transported from a cleaner to an image forming drum, in which clogging is less likely to occur and destruction of the transport mechanism can be prevented. I do.

Another object of the present invention is to provide an image forming apparatus capable of easily detecting the fullness of a waste toner tank and a process cartridge thereof.

[0016]

FIG. 1 is a diagram illustrating the principle of the present invention. A first aspect of the present invention is a cylindrical image forming drum 1.
0, latent image forming units 11 and 12 for forming an electrostatic latent image on the image forming drum 10, a developing device 3 for developing the electrostatic latent image on the image forming drum 10 with toner, and the image forming drum 10
And a cleaner 14 for removing residual toner on the image forming drum 10 after the transfer, and at least the image forming drum 10
And the cleaner 14 are integrated to form the cartridge 4, and in the image forming apparatus in which the toner removed by the cleaner 14 is stored inside the image forming drum 10, the toner storage section 40, the cleaner 14,
A carry-out unit 141 for discharging and conveying the removed toner to the toner storage unit 40, and an introduction unit 41 for stirring and conveying the toner in the toner storage unit 40 into the image forming drum 10.
42 and the provided Rutotomoni, the introducing means 41, before
An impeller 42 for stirring the waste toner in the toner storage unit 40
And a helical screw 41 integrated with the impeller 42
And a cylinder 43 communicating with the image forming drum 10.
For conveying the toner agitated in the toner storage section 40
The cylinder 43 has a position corresponding to the impeller 42.
In a U-shape, and in the image forming drum 10
It has a cylindrical shape .

A second aspect of the present invention is a cylindrical image forming apparatus.
An electrostatic latent image is formed on the ram 10 by the latent image forming units 11 and 12,
The electrostatic latent image on the image forming drum 10 is developed
Developing the toner image on the image forming drum 10 into the transfer unit 13
Is transferred to the sheet PP by the
Image forming apparatus for removing residual toner on image forming drum 10
At least the image forming drum 10 and the
The cleaner 14 is integrated, and the cleaner 14 is removed.
A process for storing the toner in the image forming drum 10.
A toner cartridge,
The storage unit 40 and the toner removed by the cleaner 14 are
A discharging unit 141 that discharges and conveys the toner to the toner storage unit 40;
The toner in the toner storage unit 40 is stored in the image forming drum 10.
When introduction means 41 and 42 for stirring and conveying are provided,
In addition, the introduction means 41 and 42 are provided in the toner storage section 40.
An impeller 42 for stirring the waste toner in the inside, and the impeller 42
And a helical screw 41 integrated with the
The toner storage unit is provided in a cylinder 43 communicating with the image forming drum 10.
40 has a function of conveying the stirred toner.
Reference numeral 3 denotes a position corresponding to the impeller 42, which has a U-shape.
However, the image forming drum 10 has a cylindrical shape.
You.

[0018]

[0019]

[0020]

[0021]

[0022]

[0023]

[0024]

[0025]

[0026]

[0027]

[0028]

According to the first and second aspects of the present invention, the cartridge
A discharging unit 1 for discharging and conveying the toner removed by the cleaner 14 to the toner storing unit 40;
41 and introduction means 41 and 42 for stirring and transporting the toner in the toner storage unit 40 into the image forming drum 10, so that the waste toner removed by the cleaner 14 is once stored in the wide tank 40. Then, it is sent to the drum 10 while stirring. Therefore, waste
The toner cannot be compacted without constantly pressing
And the transport mechanism is destroyed.
Not even.

[0029]

Further, the introduction means 41 and 42, is constituted by an impeller 42 and the helical screw 41 rotates, the in-cylinder 43 communicating with the image forming drum 10 toner storage 40
Therefore, the toner can be guided to the drum 10 while stirring the toner in the toner storage section 40. That is, the toner can be smoothly introduced and conveyed without generating any clogging.

Further, since the cylinder 43 has a U-shape at a position corresponding to the impeller 42, the toner agitated by the impeller 42 is guided into the cylinder 43, and the helical screw 41
And can be smoothly transported into the drum 10.

[0032]

[0033]

[0034]

[0035]

[0036]

[0037]

【Example】

(a) Description of Image Forming Apparatus FIG. 2 is a configuration diagram of an image forming apparatus according to an embodiment of the present invention, and FIG. 3 is a configuration diagram of a recording unit according to an embodiment of the present invention, which shows an electrophotographic printer.

In FIG. 2, reference numeral 1 denotes a recording unit;
A photosensitive drum 10; a charging roller 12 for charging the photosensitive drum 10;
And a transfer roller 13 for transferring the toner image on the photosensitive drum 10 to a sheet of paper.
And a cleaner 14 for collecting the residual toner on the photosensitive drum 10.

Reference numeral 11 denotes an optical unit which generates light modulated from a laser light source according to a video signal, scans the light with an optical scanner, irradiates the charged photosensitive drum 10, and writes a light image. Things.

Reference numeral 20 denotes a paper cassette which stores paper to be printed, 21 denotes a pick roller, which feeds out the paper from the paper cassette 20 and collides against a transport roller 22, and 22 denotes a transport roller. Is transported in synchronization with the writing of the optical image.

Reference numeral 23 denotes a manual feed guide, which inserts paper for printing paper of a size different from the paper in the paper cassette 20. Reference numeral 24 denotes a heat roller fixing device, on which a toner image is transferred by the transfer roller 13. A device for heating the sheet and fixing the toner image, a discharge roller 25 for discharging the fixed sheet, and a stacker 26 for receiving the discharged sheet and stacking them.

The operation of the electrophotographic apparatus is as follows. In response to a print command, a pick roller 21 feeds out a sheet from a sheet cassette 20, abuts a conveying roller 22, and moves the optical unit 11.
The paper is transported to the photosensitive drum 10 by the transport roller 22 in synchronization with the writing of the optical image.

The photosensitive drum 10 is charged by the charging roller 12 to which a charging potential has been applied, a light image is written by the optical unit 11, an electrostatic latent image is formed, and the developing roller 30 to which the developing potential has been applied. Is developed with a one-component non-magnetic toner, a toner image is formed, the toner image is transferred to a sheet to be conveyed by a transfer roller 13 to which a transfer potential is applied, and a residual toner on the photosensitive drum 10 is removed by a cleaner 14. Is done.

The sheet on which the toner image has been transferred is fixed by a heat roller fixing device 24 and discharged to a stacker 26 by a discharge roller 25. In this electrophotographic apparatus, since charging, development, and transfer are performed by rollers, a corona discharger is not used, so that an image can be formed without generating ozone that affects the human body.

As shown in FIG. 3, the recording unit 1 includes a process cartridge 4 in which a photosensitive drum 10, a cleaner 14, and a charging roller 12 are integrally provided, and a developing device 3.

The cleaning blade 14 is provided with a cleaning blade 14 for mechanically removing residual toner on the photosensitive drum 10.
0 and a discharge screw 141. The developing device 3
Developing roller 3 for supplying one-component toner to photosensitive drum 10
0, a supply / recovery roller 31 for supplying and recovering toner to the developing roller 30 is provided.
A blade 33 for limiting the toner layer thickness of the developing roller 30 is provided.

On the right side of the supply / recovery roller 31, a feed roller 32 for feeding the toner to the supply / recovery roller 31 is provided.
And a paddle roller 34 for stirring the toner is provided on the right side.

On the right side of the paddle roller 34, a toner cartridge 36 is set.
Is provided with a paddle roller 38 for scraping toner from the inside of the cartridge through a toner supply hole 37, and the rotation of the paddle roller 38 opens the supply hole 37 to supply the toner in the direction of the paddle roller 34.

In the developing device 3, the developing roller 30 is composed of a conductive shaft to which a developing potential is applied and a conductive porous polyurethane roller (for example, Rubicell, manufactured by Toyo Polymer Co., Ltd.). Upon contact, the one-component non-magnetic toner is charged by the hole of the conductive porous polyurethane roller and the blade 33, is conveyed to the photosensitive drum 10 while being held in the hole of the conductive porous polyurethane roller, and is developed.

In the developing roller 30, the toner can be stably supplied without clogging the hole of the conductive porous polyurethane roller with the toner. (b) Description of Process Cartridge FIG. 4 is an exploded view of a process cartridge according to one embodiment of the present invention, FIG. 5 is a cross-sectional view of the process cartridge according to one embodiment of the present invention, and FIG. FIG.

In FIG. 4, reference numeral 141 denotes a discharge screw, which is provided at the rear of the cleaning blade 140 of the cleaner 14 as shown in FIG.
The cleaning blade 140 is driven by the cleaning blade 140 to transport the waste toner removed by the cleaning blade 140 to the storage tank 40. The tip of the screw shaft 142 is formed in a semicircular shape.

Numeral 40 denotes a storage tank, as shown in FIG. 6, a space provided between the back plate 40a and the cover 44 for temporarily storing waste toner. Reference numeral 41 denotes an introduction screw. As shown in FIG. 6, as shown in FIG. 6, provided in the U-shaped pipe 43 and for transporting the waste toner in the storage tank 40 to the photosensitive drum 10, 42 is an impeller, and is provided in the storage tank 40. It is provided to agitate the waste toner in the storage tank 40.

Reference numeral 43 denotes a U-shaped pipe, which is formed in a U-shape at the impeller 42 and is open at the top. As shown in FIG.
a, which holds the photosensitive drum 10 in rotation, 4
Reference numeral 4 denotes a cover, which constitutes a partition of the storage tank 40, and is provided with a gear described later.

A connecting gear 45 has a cam 46,
47 is an idle gear fitted on the screw shaft 142 of the discharge screw 141, 47 is provided on the cover 44 and meshes with the connecting gear 45, 48 is a drive gear, provided on the shaft of the impeller 42, 47
To drive and rotate the impeller 42 and the introduction screw 41.

Reference numeral 44a denotes a front cover, and gears 45, 4
5 and a detector 49, which will be described later, is provided, and 49a is an actuator of the detector.
As shown in (B) and (C), the connecting gear 45
49b is an optical sensor, which is constituted by a transmission type sensor,
A pulse is generated by detecting the vertical movement of 9a.

This operation will be described. The waste toner at the rear of the cleaning blade 140 is discharged from the discharge screw 141.
Is transported along the arrow, and the storage tank 40 on the side
to go into.

The storage tank 40 is large enough to allow the impeller 42 to rotate while stirring the toner. The impeller 42 moves the toner into the U-shaped pipe 43 while stirring the toner. Down.

In the U-shaped pipe 43, an introduction screw 41 connected to an impeller 42 is rotated, and conveys the toner into the photosensitive drum 10. At this time, since the toner dropped into the U-shaped pipe 43 is a toner stirred by the impeller 42, it is not compacted and has a good fluidity. 10 can be transported.

In this case, if the feed screw 41 is set to have a larger transfer capacity than the discharge screw 141, the screw can be stably transferred into the photosensitive drum 10.

This is because the toner accumulation first fills the storage tank 40 and then is conveyed to the photosensitive drum 10.
This is because if the discharge / transport capacity of the cleaner 14 is larger than the introduction / transport capacity of the cleaner 14, the compaction in the storage tank 40 occurs, which is not preferable.

However, practically, a large amount of waste toner is hardly generated, which is a more preferable design. In this embodiment, the number of teeth of the gear 45 is greater than the number of teeth of the gear 48, and the rotation speed of the impeller 42 and the introduction screw 41 is increased.

Next, when the toner is full, the discharge screw 141 receives a strong conveyance drag. At this time, the shaft of the screw shaft 142 of the discharge screw 141 for driving the connecting gear 45 is made semicircular, and the other is rotated. Because it is thinner than the drive shaft, it breaks and the gear 45 stops.

For this reason, the impeller 42 and the introduction screw 4
1 is that even if the discharge screw 141 is driven, it is not driven, the actuator 49a of the detector 49 for detecting the cam 46 of the gear 45 stops, the detection pulse is no longer generated from the optical sensor 49b, and the control unit (not shown) , The fullness of the toner can be detected and the operator can be notified.

In this way, the discharged toner from the discharge screw 141 is stored in the storage tank 40 and is stored in the impeller 42.
The agitating screw 41 moves the photosensitive drum 10
The toner can be stably conveyed into the photosensitive drum 10 without causing toner clogging.

Since the storage tank 40 can be relatively small, it can be realized without increasing the size of the cartridge. Since the storage tank 40 is provided on the side of the cartridge, the storage tank 40 is along the toner conveyance path, and the conveyance screws 141, 41 Can be smoothly transported, and the cartridge can be downsized.

Further, since the shaft 142 of the discharge screw 141 is made thin to break when the toner is full, the toner does not forcibly be pushed into the photosensitive drum 10 when the toner is full, and the operation is stable. Is stopped, and this is detected by the detector 49, so that the toner full state can be detected and the operator can be notified.

(C) Description of Other Embodiments In addition to the above-described embodiments, the present invention can be modified as follows. Although the printing apparatus has been described as an electrophotographic printing apparatus, the present invention can be applied to an electrostatic recording apparatus or the like in which an image forming drum is a dielectric drum. Can also be applied.

Although the printer has been described, the present invention can be applied to a printing apparatus such as a copying machine and a facsimile. Although the charging roller 12 is also integrated with the cartridge 4, it may be formed as a separate body, or another process member may be integrated with the cartridge.

Although the detector 49 has been described as an optical sensor,
Other sensors may be used. As described above, the present invention has been described with reference to the embodiments. However, various modifications are possible within the scope of the present invention, and these are not excluded from the scope of the present invention.

[0070]

As described above, according to the present invention,
The following effects are obtained. In the cartridge 4, a toner storage unit 40, a discharge unit 141 that discharges and transports the toner removed by the cleaner 14 to the toner storage unit 40, an introduction unit 41 that introduces and transports the toner in the toner storage unit 40 into the image forming drum 10, 42, the waste toner removed by the cleaner 14 is
Once the toner enters the wide tank 40 and can be fed into the drum 10 while stirring, the waste toner is not always pushed in and cannot be compacted. Can be sent to

Furthermore, the transport mechanism is not destroyed until the toner becomes full due to the toner clogging.

[Brief description of the drawings]

FIG. 1 is a principle diagram of the present invention.

FIG. 2 is a configuration diagram of an image forming apparatus according to an embodiment of the present invention.

FIG. 3 is a configuration diagram of a recording unit according to an embodiment of the present invention.

FIG. 4 is an exploded view of a process cartridge according to an embodiment of the present invention.

FIG. 5 is a sectional view of a process cartridge according to an embodiment of the present invention.

FIG. 6 is a top view of a process cartridge according to an embodiment of the present invention.

FIG. 7 is an explanatory diagram (part 1) of a conventional technique.

FIG. 8 is an explanatory diagram (part 2) of a conventional technique.

[Explanation of symbols]

 4 Process Cartridge 10 Photosensitive Drum (Image Forming Drum) 12 Charging Roller 14 Cleaner 40 Toner Reservoir 41 Introduction Screw 42 Impeller 43 U-shaped Pipe 140 Cleaning Blade 141 Discharge Screw

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-62-223774 (JP, A) JP-A-2-239276 (JP, A) JP-A-60-249172 (JP, A) JP-A 61-223 114277 (JP, A) JP-A-4-247463 (JP, A) JP-A-59-104155 (JP, U) JP-A-1-102694 (JP, U) JP-A-58-4379 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) G03G 15/08 G03G 21/10-21/12

Claims (2)

(57) [Claims] An image forming drum (10) having a cylindrical shape, a latent image forming section (11, 12) for forming an electrostatic latent image on the image forming drum (10), and an image forming drum (10). A developing unit (3) for developing the electrostatic latent image with toner; a transfer unit (13) for transferring a toner image of the image forming drum (10) to a sheet (PP); ) To remove the residual toner, and at least the image forming drum (10) and the cleaner (1).
4) is integrated into a cartridge (4), and the toner removed by the cleaner (14) is applied to the image forming drum (1).
0) In the image forming apparatus housed in the inside, in the cartridge (4), a toner storing section (40), and a discharging means for discharging and conveying the toner removed by the cleaner (14) to the toner storing section (40). 141) and the toner in the toner storage section (40) is transferred to the image forming drum (10).
And introduction means (41, 42) for stirring and transporting the inside
The introduction means (41, 42) is connected to the toner storage section (4).
0), an impeller (42) for stirring the waste toner,
A helical screw (41) integrated with a wheel (42);
And a cylinder communicating with the image forming drum (10).
(43) The toner agitated in the toner reservoir (40)
And the cylinder (43) is located at a position corresponding to the impeller (42).
To form a U-shape, and within the image forming drum (10).
Is an image forming apparatus having a cylindrical shape . 2. A latent image on a cylindrical image forming drum (10).
Forming an electrostatic latent image in the forming section (11, 12);
The electrostatic latent image on the drum (10) is developed with toner in the developing device (3).
And transferring the toner image of the image forming drum (10) to the transfer unit.
(13) Transfer to the sheet (PP), and use the cleaner (1).
4) residual toner on the image forming drum (10) after transfer
Used in an image forming apparatus for removing at least the image
Forming drum (10) and cleaner (14) integrated
Then, the toner removed by the cleaner (14) is used for the image forming.
Process cartridge housed inside forming drum (10)
In the cartridge (4), the toner storage section (40)
The toner removed by the cleaner (14) is stored in the toner storage section.
Discharging means (141) for discharging and transporting the toner to the (40);
-The toner in the storage section (40) is applied to the image forming drum (10).
And introduction means (41, 42) for stirring and transporting the inside
The introduction means (41, 42) is connected to the toner storage section (4).
0), an impeller (42) for stirring the waste toner,
A helical screw (41) integrated with a wheel (42);
And a cylinder communicating with the image forming drum (10).
(43) The toner agitated in the toner reservoir (40)
And the cylinder (43) is located at a position corresponding to the impeller (42).
To form a U-shape, and within the image forming drum (10).
Is a process car characterized by having a cylindrical shape
Tridge.