JP3328445B2 - Electrophotographic equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic apparatus, such as a printer, a copying machine, and a facsimile, for recording on paper by an electrophotographic method using a laser. More specifically, the present invention relates to an electrophotographic apparatus including a plurality of image carriers such as photoconductors and individually including cleaning devices for cleaning the respective image carriers.

[0002]

2. Description of the Related Art Conventionally, for example, in a color laser copying machine, a first color toner image is formed on a photosensitive member serving as a first image carrier, and the image is used as a second image carrier. The image is transferred onto the intermediate transfer belt, a second color toner image is formed on the photoreceptor, and the image is transferred onto the intermediate transfer belt in the same manner. There is a type in which a color image is formed by transferring the color image onto a sheet, and the color image is transferred to a sheet at a time to perform color recording.

In such a color laser copying machine, a cleaning device for cleaning the image carrier is separately provided, and the surface of the photoconductor is cleaned each time a toner image of each color is transferred to the intermediate transfer belt. And after the color image is transferred to the paper, the surface of the intermediate transfer belt is cleaned by a belt cleaning device.

Conventionally, while a plurality of cleaning devices are provided as described above, in order to respond to a demand for downsizing of an electrophotographic device, waste toners collected by individual cleaning devices are discharged from respective toner collection ports. The configuration is such that the toner is collectively discharged to one toner collection tank.

[0005]

However, in the conventional electrophotographic apparatus, in response to the demand for downsizing, the components such as the photoreceptor are arranged by using the space as effectively as possible. As described above, the photoconductor cleaning device 1 and the belt cleaning device 2 often have different height positions.

[0006] Then, the cleaning device 1
If the height positions of the toner collection ports 2 are different, a difference in height occurs between the respective toner collection ports 1a and 2a. As a result, when the waste toner is collected, if the waste toner accumulates up to the level of the lower toner collection port 2a, the waste toner cannot be discharged from the toner collection port 2a. Had to be replaced. That is, only the hatched area in the inner space of the toner collecting tank 3 can be used as a waste toner collecting container, and the space above the hatched portion is wasted.

Therefore, for example, the toner collection tank 3 is
It is also conceivable to make the toner storage capacity larger by making it more horizontal. However, as shown in FIG. 8, when the waste toner is discharged into the toner collection tank 3, it actually accumulates in a mountain shape, so that even if it is horizontally long, it is difficult to fill the toner with every corner. However, merely increasing the size of the apparatus does not significantly increase the amount of waste toner stored. For example, as shown in FIGS. 7A and 7B, when the toner storage amount is two-dimensionally simplified and compared with the case where the toner collection tank is made horizontally long and the case where it is not so long, even if the base is doubled, The area is 4: 3, and it can be seen that there is not so much difference in the storage amount of the waste toner.

Accordingly, it is an object of the present invention to effectively utilize the internal space of the toner collection tank in the height direction without waste in the above-described electrophotographic apparatus.

[0009]

Accordingly, the present invention provides
For example, as shown in the following illustrated embodiment, a plurality of photoconductors 20
And an image carrier such as an intermediate transfer belt 35, and a separate cleaning device such as a photoconductor cleaning device 25 and a belt cleaning device 30 for cleaning the image carrier, respectively. in an electrophotographic apparatus for discharging the toner recovery tank 50 to recover the waste toner from the mouth 25b · 30b, those of the upper of the plurality of the cleaning device
Directly connected at the level of the toner collection port 25b of the
While the waste toner collected from the lower toner recovery port 30b is transported to a height position A of the upper toner recovery port 25b, and the toner is discharged from the toner discharge port 60a at the height position A. Collection tank 50
Characterized in that it is provided with a conveying means 55 for discharging the inside.

[0010]

According to the present invention, when the waste toner is discharged, the waste toner recovered from the toner recovery port 30b of the lower one of the plurality of cleaning devices is transferred by the conveying means 55 to the height of the toner recovery port 25b of the upper one. Transport to position A
Then, at the height position A, the toner
It is discharged into the collection tank 50 .

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 shows a schematic configuration of a color laser copying machine according to an embodiment of the present invention.

This color laser copying machine is designated by reference numeral 10 in FIG.
The copying machine main body 11 is placed on a paper storage table indicated by, and the color scanner 12 is placed thereon. In the paper storage table 10,
The paper cassettes 13, 14, and 15 are provided in multiple stages inside. The color scanner 12 is provided with a contact glass g for setting a copy original S on an upper surface thereof, and a light source 16 therein.
, Mirrors 17a, 17b, 17c and an imaging lens 18
And a color sensor 19, and reads a color image of the document S for each color separation light of, for example, black, blue, red, and yellow, and converts it into an electric image signal.

A photoconductor 20, which is a drum-shaped image carrier, is provided substantially in the center of the main body 11 of the copying machine. Around the photoconductor 20, a charging device 21, a rotary developing device 23, an intermediate transfer belt unit 24, a photoconductor cleaning device 25, and a static eliminator 22 are provided in this order in the driving direction indicated by the arrow.

An optical writing device 26 is provided above the charge removing device 22 and the charging device 21. Further, the developing device 2
3, a transfer device 27 is provided, a paper transfer charger 28 is provided on the right side in FIG. 2 of the transfer device 27 so as to be able to freely contact and separate from the intermediate transfer belt unit 24, and a fixing device 29 is provided on the left side. The belt cleaning device 30 is located below the photoconductor 20 and on the left side of the intermediate transfer belt unit 24 in the drawing.
Is provided.

The intermediate transfer belt unit 24 stretches an intermediate transfer belt 35, which is a belt-shaped image carrier, between a plurality of rollers so as to be driven at the same speed as the photosensitive member 20. A belt transfer charger 36 is provided at a position facing the photoconductor 20 via the intermediate transfer belt 35. The developing device 23 is provided with a black (Black) / blue (Cyan)
The red (Magenta) / yellow (Yellow) developing units 23a, 23b, 23c, and 23d are radially arranged, and the entire developing unit is rotated counterclockwise to provide each developing roller so as to be able to sequentially face the photoconductor 20. .

Further, the copying machine main body 11 is provided with a paper feed cassette 31 at the bottom thereof. Then, the paper feed cassette 31
Further, sheets of various sizes are stored in the sheet cassettes 13, 14 and 15 described above. A manual paper feed tray 32 is provided on the right side of the copying machine main body 11 in the drawing.

Now, when making a copy of the copy original S,
The original S is placed on the contact glass g and set.
The copy is started by appropriately selecting the paper size and the like. Then, for example, the paper P is sent out from the paper feed cassette 31,
The sheet P is conveyed to a lower side of the intermediate transfer belt 35 at a timing by a registration roller 33. The color scanner 12 reads, for example, a black image (image of the first color) on the copy document S and converts it into an image signal.

On the other hand, the photosensitive member 20 is driven in a counterclockwise direction as indicated by an arrow. At this time, the surface of the photosensitive member 20 is uniformly charged by the charging device 21, and based on the black image signal, the optical writing device 2
In step 6, a laser beam is irradiated to form an electrostatic latent image. Then
When passing through the position of the black developing device 23a, the electrostatic latent image is visualized by black toner. Then, a predetermined bias voltage is applied to the belt transfer charger 36 to transfer the black toner image to the intermediate transfer belt 35. After the transfer, the residual toner adhered to the surface of the photoconductor 20 is scraped off by the cleaning blade 37 and the fur brush 38 of the photoconductor cleaning device 25 to clean the photoconductor 20.

Subsequently, the color scanner 12 reads, for example, a blue image (image of the second color) on the copy original S, and converts it into an image signal. Then, based on the blue image signal, similarly, optical writing is performed on the surface of the photoconductor 20 by the optical writing device 26 to form an electrostatic latent image on the photoconductor 20. When passing through the position of the container 23b, the electrostatic latent image is developed with blue toner.
Then, while transferring this blue toner image to the intermediate transfer belt 35, the surface of the photoconductor 20 is cleaned again by the photoconductor cleaning device 25. Then, this is repeated to transfer a four-color superimposed toner image to form a color image on the intermediate transfer belt 35.

Then, a predetermined bias voltage is applied to the paper transfer charger 28, the paper transfer charger 28 is brought into contact with the intermediate transfer belt 35, and the color image is transferred onto the paper P conveyed by the registration rollers 33 at one time. . After the color image transfer, the paper P is transported by the transport device 27 to the fixing device 29.
And the fixing device 29 fixes the color image. After fixing, the paper P is discharged by a discharge roller 40 to a discharge tray 41.
Discharge up.

On the other hand, after the transfer of the color image, the residual toner adhering to the surface of the intermediate transfer belt 35 is scraped off by the cleaning blade 39 of the belt cleaning device 30 to clean the intermediate transfer belt 35.

In the copying machine described above, as shown by the chain line in FIG. 3, the waste toner collected by the photoconductor cleaning device 25 and the belt cleaning device 30 is discharged to the near side of the photoconductor 20 in the drawing. One toner collection tank 50 is provided.

On the other hand, the photosensitive member cleaning device 25 and the belt cleaning device 30 have a case 25 respectively.
The transfer coils 51 and 52 which transmit the driving force of a drive motor (not shown) and rotate are provided at the bottom of the a and 30a. Then, toner recovery ports 25b and 30b indicated by chain lines are provided in the cases 25a and 30a, respectively, toward the toner recovery tank 50 on the near side in the figure.

As shown in FIG. 1, the toner collecting ports 25b and 30b are opened at respective height positions A and B. The upper toner collection port 25b
Is directly connected to the toner collection tank 50 at an upper position thereof. On the other hand, the lower toner collecting port 30b is connected to a lower end portion of a transport pipe 60 provided in the waste toner transport means 55.

The conveying means 55 is provided with the conveying pipe 60,
It extends to the height position almost the same as the height position A, which is diagonally upper right in FIG. The transport pipe 60 is provided at its upper end with a toner outlet 60a toward the toner recovery tank 50. The transfer coil 61 is provided in the transfer pipe 60.
Is provided. A gear 62 is provided at the lower end of the transfer coil 61, for example, as shown in FIG. 4, and a gear 63 for transmitting the drive rotation of the drive motor is provided at one end on the front side of the transfer coil 52. Gear 6
3 is meshed with the gear 62.

In the above-described embodiment, when the photoconductor 20 is cleaned by the photoconductor cleaning device 25 shown in FIG. 1, the waste toner falling on the transport coil 51 is carried to the near side by the transport coil 51. Collecting and toner collecting port 25
b directly into the toner recovery tank 50.

Further, when the intermediate transfer belt 35 is cleaned by the belt cleaning device 30, the waste toner falling on the transport coil 52 is carried by the transport coil 52 to the front side to be recovered from the toner recovery port 30b. The collected toner is conveyed to a height position A by a conveyance coil 61, and the toner collection tank 50 is transferred from the toner discharge port 60a at the height position.
Drain into. Then, as shown by hatching in FIG. 1, the waste toner is discharged to the height position A of the upper toner recovery port 25b, that is, until most of the internal space of the toner recovery tank 50 is filled with the waste toner.

As shown in FIG. 5, for example, the transfer pipe 60 of the transfer means 55 is temporarily connected to the upper toner recovery port 25.
Even if it extends above the height position A of b, since the height position A is the limit of the waste toner storage height, parts such as the transport pipe 60 longer than that height become useless,
It is not desirable.

As shown in FIG. 6, the upper photosensitive member cleaning device 25 is also connected to the above-described conveying means 55 to increase the limit of the waste toner storage height, thereby increasing the limit of the waste toner storage height.
Although it is conceivable to further increase the toner storage capacity, this configuration is not preferable because the number of parts increases and the cost increases.

[0030]

Therefore, according to the present invention, in an electrophotographic apparatus provided with a plurality of cleaning devices, each of which has a different height position of the toner collecting port, the toner collecting port of the lower one of the plurality of cleaning devices can be used. The collected waste toner is transported by the transporting means to a level above the toner recovery port of the upper one, and the toner is discharged from the toner discharge port at that level.
Since the toner collecting tank is configured to be discharged into the toner collecting tank, the internal space of the toner collecting tank can be effectively used in the height direction without waste.

[Brief description of the drawings]

FIG. 1 is a schematic view showing a configuration of discharging waste toner from a vertical cleaning device of a color laser copying machine according to an embodiment of the present invention to a toner recovery tank.

FIG. 2 is an overall schematic configuration diagram of the color laser copying machine.

FIG. 3 is a schematic configuration diagram showing a part of FIG. 2 in an enlarged manner and showing arrangement positions of a photoconductor cleaning device, a belt cleaning device, a toner collection tank, and the like.

FIG. 4 is a schematic configuration diagram illustrating a drive transmission mechanism of a transfer coil of a transfer unit.

FIG. 5 is a schematic diagram showing an example in which a conveying pipe of a conveying unit is extended to be higher than a height position of an upper toner collecting port for reference.

FIG. 6 is a schematic diagram showing an example in which a conveying unit is also connected to an upper photosensitive member cleaning device for reference.

FIG. 7 is a schematic view of a conventional color laser copying machine in which a photoconductor cleaning device and a belt cleaning device are installed at different height positions.

FIGS. 8A and 8B are explanatory diagrams for simplifying and comparing two-dimensionally the amount of stored toner when the toner collection tank is made horizontally long and when it is not.

[Explanation of symbols]

 Reference Signs List 20 photoconductor (image carrier) 25 photoconductor cleaning device 25b upper toner recovery port 30 belt cleaning device 30b lower toner recovery port 35 intermediate transfer belt (image carrier) 50 toner recovery tank 55 conveying means A upper toner recovery Mouth height position

Continuation of the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) G03G 21/10-21/12 G03G 15/01-15/01 507

Claims (1)

(57) [Claims] 1. A cleaning apparatus comprising: a plurality of image carriers; and a cleaning device for individually cleaning the image carriers. In the electrophotographic apparatus, the cleaning device is directly connected to the upper one of the plurality of cleaning devices at the level of the toner collecting port.
The toner recovery tank is connected to the toner recovery tank, and the waste toner recovered from the lower toner recovery port is conveyed to the height of the upper toner recovery port. An electrophotographic apparatus comprising a transport means for discharging the inside of the apparatus.