JPH0548920B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an image forming apparatus such as a copying machine, a facsimile machine, and a printer, and more particularly to an image forming apparatus having a collection tank for collecting residual toner removed from the surface of an image transfer carrier.

For example, as shown in FIG. 1, an image forming apparatus such as a copying machine has a charging device 5, an exposure device 6, a developing device 7, and a transfer device arranged around a drum-shaped photoreceptor 1 having a photoconductive layer on its surface. The photoreceptor 1 rotates clockwise in synchronization with the movement of a document table (not shown), and is first charged with a predetermined charge by the charging device 5. Then, exposure device 6 sequentially exposes the image to form an electrostatic latent image on the surface of photoreceptor 1 corresponding to the original image on the original platen. After this electrostatic latent image is visualized as a toner image by a developing device 7, the toner image is transferred and carried on a transfer paper 10 fed from a paper feeder 11 by the transfer device 8. The transferred transfer paper 10 is then separated from the photoreceptor 1 and sent to the fixing device 12 by the conveying device 20, where it is fixed as a final image.

On the other hand, the residual toner on the photoreceptor 1 to which the toner image has been transferred is removed and collected by the residual toner collecting device 3, and then the static electricity is uniformly removed from the surface of the photoreceptor 1 by the static eliminator 9 in preparation for the next copying.

The residual toner removed by the residual toner collection device 3 is discharged via the conveyance mechanism 33 into a collection tank (not shown) disposed close to the front side wall surface of the housing. The collection tank is conventionally formed as a collection container so that it can be removed separately from the casing.
In order not to interfere with the attachment of the various copying devices 1 to 7, 9, and 10 and the conveyance of the transfer paper 10, it is disposed outward from the side end surface of the photoreceptor 1 and close to the inner wall surface of the casing of the image forming apparatus. are doing.

However, the amount of residual toner accumulated in the collection container is extremely large, approximately 100 c.c./1000 copies (number of copies) or more, and therefore, the collection container must be replaced frequently and the remaining toner removed. In order to avoid various accidents caused by overflow from the collection container, its volume must necessarily be increased. A special space is required for the arrangement, and the overall size of the device cannot be avoided.

In particular, in the image forming apparatus with the above configuration, the total length of the photoconductor 1 is regulated by the maximum width of the transfer paper 10 to be copied, so the total length of the photoconductor 1 cannot be reduced. In order to reduce the size of the entire image forming apparatus, an important factor is how to reduce the size of the special gap between the end surface of the photoreceptor 1 and the inner wall of the housing.

In view of such technical requirements, the present invention effectively forms a predetermined space inside the side edge of the photoreceptor without interfering with the attachment of the various process means or the conveyance of the transfer paper, and within the space, the recovery By configuring the tank so that it can be extended,
It is an object of the present invention to provide an image forming apparatus in which a portion of the image forming apparatus can be made significantly thinner than in the past, and as a result, the apparatus as a whole can be made smaller, lighter, and lower in cost.

The gist of the present invention is to provide an image forming apparatus equipped with a collection tank for collecting residual toner, in which a collection port for receiving residual toner of the collection tank is located in an area outside the width of the transfer paper conveyance path. A recovery tank is provided and extends from the area into the transfer paper conveyance path, so that at least one surface of the extending portion of the recovery tank forms part or all of the transfer paper conveyance path.

The present invention will be explained below based on the drawings.

2 to 4 show an embodiment of the present invention applied to the image forming apparatus having the above structure, and the same reference numerals as in FIG. 1 indicate the same members.

As is well known, the conveying device 20 includes a pair of rotating rollers 21 and 22 arranged parallel to one axis of the photoreceptor, and a conveying belt 23 suspended between the rollers 21 and 22.
and an L-shaped support plate 24 that rotatably supports the rollers 21, 22.
By rotating the conveyor belt 23, the conveyor belt 23 rotates toward the fixing device (in the direction of the arrow), and the transfer paper 10 separated from the photoreceptor 1 is closely placed on the upper surface of the conveyor belt 23 forming a conveyance path. The configuration is such that the image is sent to the fixing device 12 side.

The conveyance device 20 is disposed below the recovery device 3, and its side end, that is, the mounting position of the support plate 24 is largely deviated inward from the photoreceptor side end 1a, so that the inner wall surface 51 of the casing 50 and A space S is formed between the support plates 24 in which a recovery tank 40, which will be described later, can be accommodated.

On the other hand, the residual toner collection device 3 is arranged around the photoreceptor 1 and extends parallel to the axis of the photoreceptor.
A rotating cleaner 31 that is in pressure contact with the surface of the photoreceptor 1 and rotates while sliding on the surface, a scraping member 32 that scrapes off toner adhering to the cleaner 31, and conveys the residual toner scraped off by the scraping member 32. a transport mechanism 33 for
A blade member 34 that removes residual toner that could not be removed by step 1, and a frame 3 that covers them.
5.

The conveyance mechanism 33 includes a conveyance passage 33a extending from the side end of the frame body 35 toward the inner wall surface 51 side, a screw shaft-shaped conveyance member 33b disposed near the bottom of the frame body, and a conveyance member 33b extending downward from the outer peripheral surface on the exit side of the conveyance passage 33a. The residual toner accumulated near the bottom surface of the frame body 35 is conveyed to the discharge port 33c by the rotation of the conveying member 33b,
It is discharged into the recovery tank 40.

The collection tank 40 may be formed integrally with the housing 50, but in this embodiment, it is formed separately and removably as a collection container. The collection tank 40 has a substantially rectangular shape, and the discharge port 33c is located on the upper surface adjacent to the side wall of the apparatus away from the width of the corresponding transfer paper transport path, in other words, between the side end 1a of the photoreceptor and the inner wall surface 51 of the casing 50. In addition to forming the opening 41, the recovery tank 40 is extended into the space S in the transfer paper conveyance path, and is arranged so that its front end side wall surface approaches the vicinity of the conveyance device 20.

The collection tank 40 is shaped so as to be located over almost the entire width between the rotating rollers 21 and 22 of the conveying device 20, and has a shape on the upper surface that is substantially parallel to the conveying direction of the conveying device 20. A plurality of rib-like protrusions 42 are formed over the entire width.

The rib-like protrusion 42 is configured such that its upper surface is substantially on the same plane as the upper surface of the conveyor belt 23,
The transfer paper 10 serves as a conveying path surface.

Incidentally, if the collection tank 40 is made of a resin having a small coefficient of friction, the conveyance of the transfer paper becomes easier.

According to this embodiment, a space S in which the collection tank 40 can be stored is formed on the transport device 20 side inside the photoreceptor side end 1a, and the collection tank 40 is arranged to extend within the storage space S. Since the upper surface of the recovery tank 40, that is, the upper surface of the rib-like protrusion 42 is formed to be the surface of the transfer paper 10 conveying path of the conveying device 20, a special empty space is created between the photoreceptor side end 1a and the inner wall surface 51 of the housing 50. T can be made significantly smaller than in the prior art, and even if the transfer paper 10 has a width that is approximately the same as the entire length of the photoreceptor 1, the collection tank 40 will not impede its conveyance.

In particular, in this embodiment, a rib-like protrusion 42 is formed on the upper surface of the collection tank 40 located in the storage space S,
By forming the upper surface of the protrusion 42 so as to be substantially on the same plane as the conveyance path of the conveyance device 20, a coplanar conveyance path surface is formed over almost the entire length of the photoreceptor 1, and the transfer paper When conveying the transfer paper 10, the transfer paper 10 is brought into close contact with the upper surface of the collection tank 40, and can be conveyed effectively without changing direction.

FIG. 5 shows another embodiment of the present invention, and the differences from the previous embodiment will be mainly explained.

The conveyance device 20' is arranged over almost the entire length of the photoreceptor 1, and has a pair of rotating rollers 21', 2.
2', an annular ring member 26 with high frictional resistance is wrapped around the entire length of the belt 2', and a space S' is created over almost the entire length between the rotating rollers 21' and 22'. form.

On the other hand, the recovery tank 40' has a substantially horizontal T-shape, and is located on the upper surface adjacent to the side wall of the apparatus away from the width of the transfer paper conveyance path corresponding to the residual toner discharge port 33c, in other words, at the photoreceptor side end 1a. A collection port 41' that is fitted into the discharge port 33c is formed between the inner wall surface 51 of the casing 50, and a collection tank 40' is extended into the space S' in the transfer paper conveyance path, and the rotating roller 2
The collection tank 40' is arranged so as to be located over almost the entire length between 1' and 22'.

Further, a rib-like projection 42' similar to that of the embodiment described above is formed on the upper surface of the collection tank 40', but the rotating rollers 21', 2
2′, the rib-like projection 4
The upper surface 2' only needs to be formed so that the transfer paper 10 can be conveyed without changing direction or bending, so it does not necessarily need to be set on substantially the same plane as the conveyance path surface, and may be set slightly lower. .

In this embodiment, since the collection tank 40' can be arranged over almost the entire length of the conveying device 20', that is, the photoreceptor 1, the volume of the collection tank 40' can be made very large. The recovery tank 40'
Since there is no need to replace the casing 50, it is possible to provide an image forming apparatus having the collection tank 40' integrated with the casing 50.

As described above, according to the present invention, the collection port for receiving residual toner of the collection tank is provided in an area outside the width of the transfer paper transport path, and the collection tank extends from the area into the transfer paper transport path. Since at least one surface of the extending portion forms part or all of the transfer paper conveyance path, it is possible to effectively connect the photoconductor side without interfering with various process means arranged around the photoconductor or with the transfer paper conveyance. A predetermined space is formed inside the end, and a recovery tank for collecting residual toner can be extended and arranged within the space. As a result, the above-mentioned space between the photoreceptor side end surface and the inner wall surface of the casing of the image forming apparatus can be disposed. It is possible to make the special cavity for housing the recovery tank much smaller (thinner) than in the past, and the entire device can be made smaller and lighter.

In addition, the fact that the collection tank forms part or all of the transfer paper conveyance path means that on the one hand, the conveyance path forming member can be made smaller;
Cost reduction can be achieved.

It is possible to provide an image forming apparatus that has various remarkable effects such as, and has extremely high practical value.

[Brief explanation of the drawing]

FIG. 1 is a schematic explanatory diagram showing the configuration of an image forming apparatus to which the present invention is applied. Figures 2 to 4 show one embodiment of the present invention, with Figure 2 being a sectional view of main parts, and Figure 3
Figures 4 to 4 are lines A-A' and B- of Figure 2, respectively.
It is a sectional view taken along the line B'. FIG. 5 is a plan view of main parts showing another embodiment of the present invention.

Claims (1)

[Scope of Claims] 1. In an image forming apparatus equipped with a collection tank for collecting residual toner, a collection port for receiving residual toner of the collection tank is provided in an area outside the width of a transfer paper conveyance path, and transfer from the area is provided. An image forming apparatus characterized in that a recovery tank extends within a paper conveyance path, and at least one surface of the extending portion of the recovery tank forms part or all of the transfer paper conveyance path.