JPH10222035A - Toner capturing device for image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the falling of toner particles in exchanging a filter without facing a duct vertically. SOLUTION: In a toner capturing device for generating an air flow flowing to a horizontal direction inside a duct to capture toner particles floating from an image forming part. A filter 46 exchangeably arranged in the duct is formed in a shape zigzag bent. Flat parts 46a of the filter 46 are mutually vertically arrayed so as to have upper and lower surfaces respectively and two bent parts 46b holding each flat part 46a are arranged on the upstream and downstream sides of the air flow respectively. The toner particles 47 floating on the air flow enter the gaps between the flat parts 46a of the filter 46 to be captured. At the bottom of the filter 46, a catch pan 52 extended to upstream side from the filter 46 is fixed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for collecting floating toner in an image forming apparatus using an electrophotographic system.

[0002]

2. Description of the Related Art In an image forming apparatus using an electrophotographic method, such as an electrostatic copying machine or a laser beam printer, the surface of an image carrier such as a photosensitive drum is uniformly charged by a charger, and the photoelectric conversion by a laser beam is performed. By utilizing the effect, a latent image corresponding to an image to be formed is written on the charged surface, and toner is transferred from the developing device to the latent image to be visualized. The toner image thus formed on the surface of the image carrier is directly or indirectly transferred to an image forming object such as paper or an OHP sheet.

In a developing device, toner is charged by being stirred and toner is electrostatically attached to a charged latent image on the surface of an image carrier. Some are not fully charged. Such toner particles do not adhere to the image carrier and float in the atmosphere. If this is left unattended, the inside of the image forming apparatus will be stained, and in an unexpected case, toner particles will adhere to the sheet on which the image is to be formed, causing image stains. Further, when toner particles adhere to the charging corotron, the electric field generated by the corotron is disturbed, and defects such as white streaks are generated in the image.

For this reason, the image forming apparatus is provided with a device for collecting floating toner in an atmosphere as shown in FIG. This collecting device includes a horizontal duct 31 into which floating toner flows, and the duct 31 is constituted by two conduits 32 and 33. These pipelines 3
A flange is provided at the end of each of the flanges 2 and 33, and the flanges are opposed to each other and are connected by connecting means (not shown). A packing 34 is interposed between these flanges.

[0005] Inside the duct 33 of the duct 31, a fan 35 for sucking toner is provided.
A flat filter 36 made of a filter material for collecting toner is disposed inside the filter. This fan 35 causes an airflow from the inside of the image forming apparatus to the outside,
The toner particles 37 in the airflow are collected by the filter 36 so that the toner particles 37 are not released to the outside of the image forming apparatus.

Here, as shown in FIG. 1 (B), the upstream pipeline 32 and the pipeline 33 can be removed. The filter 36 can be removed. Thus, the filter 36 that has collected the toner particles 37 is replaced with a new one.

[0007]

However, the filter 36 shown in FIG. 1 is a simple flat plate and is set up vertically inside the horizontal conduit 32.
In some cases, the toner particles 37 are easily spilled from the filter 36, and may stain the inside or the periphery of the image forming apparatus.

Therefore, conventionally, when it is expected that a large amount of toner particles 37 are to be collected, as shown in FIG. 2, the duct 31 is made vertical and the air flow is directed downward from above. In some cases, a filter 36 is provided so as to cross this air flow. The filter 36 shown in FIG. 2 is a bag type in which a frame 36b is attached to the entrance of a bag-shaped filter medium 36a in order to collect a large amount of toner particles 37.

However, depending on the type of the image forming apparatus, it may not be possible to vertically orient the duct 31 in this way due to the arrangement of other components. Also, duct 3
Even if it can be provided vertically, it may require a significant design change in other parts and may complicate the image forming apparatus.

The present invention has been made in view of the above circumstances, and provides a toner collecting device for an image forming apparatus which does not require the duct to be vertically oriented and which has a small amount of toner particles falling when the filter is replaced. The purpose is to do.

[0011]

In order to solve the above-mentioned problems, a toner collecting device of an image forming apparatus according to the present invention comprises a toner collecting device for electrostatically adhering toner to a sheet; A duct, an airflow generating means for generating an airflow flowing in the lateral direction inside the duct, and flowing the toner particles, and the toner particles arranged exchangeably inside the duct and flowing by the airflow. And the filter has a shape bent in a zigzag pattern having alternating flat portions and bent portions, and the filters are arranged one above the other such that the flat portions have an upper surface and a lower surface, respectively. And two bent portions sandwiching each of the flat portions are disposed on the upstream side and the downstream side of the airflow, respectively.

According to the above configuration, the toner particles flowing inside the duct are collected by the zigzag filter. Here, the flat portions of the filter are arranged one above the other, so that the toner particles enter between the flat portions. Therefore, for example, even when the duct is oriented horizontally, it is possible to reduce the occurrence of toner particles falling when the toner collecting device is used. Further, even if the filter is slightly moved at the time of replacement of the filter, it is possible to reduce the occurrence of toner particles falling. Therefore, even in an image forming apparatus in which there is not enough space for vertically turning the duct, contamination of the inside and the surroundings due to the drop of toner particles is reduced without complicating the structure. Moreover, even if the duct is not vertically oriented, the toner particles enter between the flat portions, so that the amount of the collected toner particles can be increased. Further, the filter has a simple configuration in which the filter is bent in a zigzag and is arranged as described above, and the production cost is not significantly increased.

Further, the toner collecting device of the image forming apparatus according to the present invention has a duct in which toner particles floating from an image forming section for electrostatically adhering toner to a sheet flow, and a horizontal direction inside the duct. An airflow generating means for generating an airflow flowing through the toner particles, a filter disposed exchangeably inside the duct to collect the toner particles flown by the airflow, and a filter below the filter. And a catch pan removably engaged with the duct and arranged substantially horizontally, wherein the catch pan extends upstream of the airflow from the filter. It may be something.

According to the above configuration, the catch pan extending upstream of the filter in the airflow is fixed below the filter. For this reason, for example, even when the toner particles fall off the filter when the filter is replaced, the toner particles are received on the catch pan and do not fall below it. Therefore, even in an image forming apparatus in which there is not enough space for vertically turning the duct, the inside and surroundings due to the drop of toner particles are reduced without complicating the structure. Moreover, the catch pan is fixed below the filter, and the catch pan can be detachably engaged with the duct, so that the manufacturing cost does not increase significantly.

Further, according to the present invention, there is provided a toner collecting device for an image forming apparatus, comprising: a duct into which toner particles floating from an image forming unit for electrostatically attaching toner to a sheet flow; An airflow generating means for generating an airflow flowing through the airflow and causing the toner particles to flow, and a filter arranged exchangeably inside the duct to collect the toner particles flown by the airflow, the filter comprising: Has a bag-like shape opened toward the upstream side of the airflow and closed at the downstream side, includes a flat upper portion and a lower portion, and the lower portion is wider than the upper portion. May be used.

According to the above configuration, the bag-shaped filter having the flat upper and lower portions collects the toner particles flowing inside the duct. Here, since the lower portion is wider than the upper portion of the filter, it is possible to reduce the occurrence of toner particles falling when the filter is replaced, for example. Therefore, even in an image forming apparatus in which there is not enough space for vertically turning the duct, the inside and surroundings due to the drop of toner particles are reduced without complicating the structure. Moreover, even if the duct is not vertically oriented, the toner particles enter the bag-shaped filter, so that the trapping amount can be increased. In addition, the filter can be formed in a bag shape and simply arranged as described above, which does not cause a significant increase in manufacturing cost.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. 1. First Embodiment A. First Embodiment First, FIG. 3 is a schematic side view showing an image forming section of an electrostatic copying machine provided with a toner collecting device according to an embodiment of the present invention. In the figure, reference numeral 1 denotes a box-shaped photoconductor unit (support unit). A columnar photosensitive drum (image carrier) 2 is rotatably attached to the photosensitive unit 1. That is, the photosensitive drum 2 is rotatably supported between the side wall 1a on the near side in the figure and the same side wall on the far side in the figure. The right side of the side wall 1a in the figure is open, so that the surface of the photosensitive drum 2 is exposed.

A protruding space is provided above the photoreceptor unit 1, and a charging corotron 5 is provided therein. The photosensitive drum 2 is rotated clockwise in the figure by a drive motor (not shown), and the surface thereof is uniformly charged by an electric field generated by the charging corotron 5. An exposure device 6 is disposed above the photoreceptor unit 1. The exposure device 6 irradiates a laser beam onto the charged surface of the photoreceptor drum 2 to form an image to be formed by a photoelectric effect. The corresponding latent image is the photosensitive drum 2
Formed on the surface.

Further, a developing unit 7 is arranged close to the photosensitive drum 2. The developing unit 7 includes a plurality of developing units 7a, 7b,
7c and 7d are provided. Then, the developing unit 7
Each time the photoreceptor unit 1 makes one rotation, the photoreceptor drum 2 rotates the photoreceptor drum 2 by 90 ° about a rotation shaft 7e and by developing units 7a, 7b, 7c and 7d, respectively. To supply. The toner is agitated in each of the developing units 7a, 7b, 7c, 7d, and is charged so as to have a charge that can be attached to the latent image on the photosensitive drum 2. As a result, not only the latent image is visualized, but also the toner of each color is superimposed, and a multicolor toner image is formed on the surface of the photosensitive drum 2.

In the figure, a pre-transfer charging corotron 25 is disposed diagonally below and to the right of the photosensitive drum 2. When the toner image comes to the position of the pre-transfer charging corotron 25 with the rotation of the photosensitive drum 2, the electric charge of the toner is optimized by the electric field generated by the pre-transfer charging corotron 25. At the same time, the potential on the surface of the photosensitive drum 2 is also optimized.

Further, below the photosensitive drum 2, a transfer drum 8 is rotatably arranged, and is brought into contact with the photosensitive drum 2. Between the transfer drum 8 and the photosensitive drum 2, a sheet 15 to be image-formed is conveyed by rolls 9 to 14 and the like. A transfer corotron 16 is arranged inside the transfer drum 8. While the sheet 15 is passed between the photosensitive drum 2 and the transfer drum 8, the toner image on the photosensitive drum 2 is transferred onto the sheet 15 by the action of the electric field formed by the transfer corotron 16.

A separating claw 17 is arranged on the left side of the transfer drum 8, and the sheet 15 on which the toner image has been transferred is separated from the transfer drum 8 by the separating claw 17.
Further, a fixing device 18 is provided on the left side. The fixing device 18 includes a heating roll 19 and a pressure roll 20 that are arranged to face each other. The sheet 15 is passed between the two, and during this time, the toner image is fixed to the sheet 15 by receiving heat and pressure. Let me do. Further, on the left side, discharge rolls 21 and 22 are arranged, and the sheet 1
5 is discharged to the outside of the image forming apparatus through the space between the discharge rolls 21 and 22.

As shown in FIG. 2, a charge removing corotron 26 and a cleaning blade 27 are further provided inside the photoreceptor unit 1. After the transfer of the toner image, the surface of the photosensitive drum 2 is
, And is further cleaned by the cleaning blade 27.

B. Configuration of Toner Collection Device In FIG. 3, a toner collection device 40 is disposed below the developing unit 7. This toner collecting device 4
Reference numeral 0 includes a duct 41 that is configured to blow air from the inside of the image forming apparatus to the outside. At the left end of the duct 41, an air inlet 41a is provided. This air inlet 41
a is located immediately below the position where the photosensitive drum 2 receives toner supply from any of the developing units 7a, 7b, 7c, 7d adjacent to the developing unit 7. The position where the photosensitive drum 2 receives the supply of toner from the developing unit 7 is also the position where the floating toner is most likely to be generated.

A flat catch pan 42 is mounted near the air inlet 41a of the duct 41, and the movement of the floating toner below the catch pan 42 is restricted by the catch pan 42. Finally, the air flows into the duct 41 through the air inlet 41a. This prevents the floating toner from adhering to the pre-transfer charging corotron 25, the transfer drum 8, and the like below the developing unit 7, and also prevents unexpected toner contamination on the sheet 15.

The duct 41 is horizontal except that the left side in the figure is inclined. The right portion is formed so that the sectional area gradually increases. At the right end of the duct 41, an air outlet 41b opened toward the outside of the image forming apparatus is provided.

FIG. 4 is an enlarged sectional view showing a central portion of the duct 41. As shown in FIG. Air outlet 41b of duct 41
A fan 45 is provided inside the side. The fan 45 generates an airflow from the air inlet 41a to the air outlet 41b in FIG. 3, that is, an airflow from the inside of the image forming apparatus to the outside. Due to this airflow, the toner particles floating from the inside of the image forming apparatus flow into the duct 41 through the air inlet 41a. As shown in the drawing, since the center of the duct 41 is horizontal, the airflow flows in the horizontal direction, that is, from left to right in FIG.

On the upstream side of the airflow from the fan 45, a filter 46 for collecting the toner particles in the airflow is disposed inside the duct 41. Filter 4
Reference numeral 6 denotes a pleated type having a zigzag shape having flat portions 46a and bent portions 46b alternately. The flat portions 46a are vertically arranged so as to have an upper surface and a lower surface, respectively, and two bent portions 46b sandwiching each of the flat portions 46a are arranged on the upstream side and the downstream side of the airflow, respectively. This filter 46
Thus, the duct 41 is divided into two spaces, an upstream side and a downstream side, and the air flows through the filter 46 to the downstream side, but the toner particles do not flow to the downstream side.

FIG. 5 shows an example of the filter 46 used in the toner collecting device 40. First, the filter 46 shown in FIG. 5A is obtained by forming a filter material into a zigzag sheet shape. As shown, the flat portions 46a are rectangular and have substantially the same shape and size. The filter medium used here is a nonwoven fabric. However, besides this, electrostatic filter media knitted with charged fibers, electrostatic filter media with net attached to the surface of the electrostatic filter media so that the tip of the fiber does not protrude, filter media with dust collector plate It may be.

The filter 46 shown in FIG.
A resin reinforcing rib 48 is attached to the bent portion 46b of the filter medium shown in FIG. In the figure, the rib 48 is
The ribs 48 are attached to every other bent portion 46b (only the bent portion 46b on the left front side is attached), but the rib 48 may be attached to the other bent portion 46b.

The filter 46 shown in FIG.
It has two side plates 49 to which both side ends of the filter medium shown in FIG. These side plates 49 prevent the relative movement of the flat portion 46a. As shown, these side plates 4
It is more preferable to provide a rectangular frame-shaped connection plate 50 for connecting the first and second connection plates 9. The connection plate 50 is directed to the upstream side of the air flow, and through a rectangular opening 50a formed here, the toner particles are collected by the filter medium. The side plate 49 and the connecting plate 50
Are made of resin, are formed integrally with each other, and are later fixed to the filter medium. However, the side plate 49 and the connecting plate 50 may be formed of the same material as the filter medium. It is also possible to use a filter having both the rib 48 shown in FIG. 5B and the side plate 49 shown in FIG. 5C.

Referring back to FIG. 4, an opening 51 through which the filter 46 can be inserted and removed is formed in the bottom wall of the duct 41. On the other hand, a catch pan 52 made of metal or resin is fixed below the flat portion 46a at the bottom of the filter 46. The upstream and downstream edge portions 52a and 52b of the catch pan 52 are
FIG. 4 is bent so as to ride on the peripheral portion of FIG.
As shown in (A), the edge portions 52a and 52b
The catch pan 52 is disposed substantially horizontally while riding on the periphery of the first. In this way, filter 4
6 is attached to the duct 41, and the uppermost flat portion 46 a is pressed against the upper wall of the duct 41 by the elasticity of the filter 46 during use.

Here, the upstream edge 52a of the catch pan 52 extends upstream of the airflow from the filter 46, and the downstream edge 52b extends downstream of the airflow from the filter 46. Has been extended to. In the direction of the airflow, the length from the edge 52a to the edge 52b is equal to the length of the opening 51.
, But is long enough to insert one of the edge portions 52a and 52b into the duct 41 first and insert the other edge portion 52a or 52b into the duct 41 later. It is becoming. Thus, the filter 46 that has collected a large amount of the toner particles 47 can be replaced with a new one. That is, when removing the filter 46 from the duct 41, the catch pan 5
2 are slightly shifted in the direction of the air flow, and the edge portions 52a, 52
After exposing one of b to the outside of the duct 41, the other edge 52a or 52b may be exposed to the outside of the duct 41.

C. Effect of Toner Collection Device According to the above configuration, the filter 46 bent zigzag.
Accordingly, the toner particles 47 flowing inside the duct 41 are collected. Here, since the flat portions 46a of the filter 46 are arranged up and down with respect to each other, the toner particles 47 enter between the flat portions 46a by the airflow, and even after the airflow is stopped, the flat portions 46a remain. And is held by the frictional force. Therefore, even when the duct 41 is oriented horizontally as shown in the figure, the toner particles 47 hardly fall off when the toner collecting device 40 is used. Further, even when the filter 46 is slightly changed during the replacement of the filter 46, the occurrence of the toner particles 47 falling can be reduced.

Further, even if the toner particles 47 fall off from the filter 46 when the filter 46 is replaced, the toner particles 47 are received by the catch pan 52 extending to the upstream side of the airflow from the filter 46 and do not fall below it. . Moreover, since the filter 46 is fixed on the catch pan 52, the filter 46 that has collected the toner particles 47 does not fall off the catch pan 52.

Accordingly, even in an image forming apparatus in which there is not enough space for the duct 41 to be directed vertically, contamination of the inside and the surroundings due to the drop of the toner particles 47 is reduced without complicating the structure. In addition, even if the duct 41 is oriented horizontally, the amount of trapped toner particles 47 can be increased because the toner particles 47 enter between the flat portions 46a. Furthermore, the filter 46 is bent in a zigzag manner, the catch pan 52 is fixed below the filter 46, and the filter 46 is simply arranged as described above. This does not cause a significant increase in manufacturing cost.

D. Preferred Examples of Filter (1) FIG. 6 shows a further preferred example of the filter 46 used in the toner collecting device 40 described above. In the filter 46 shown in the drawing, among the flat portions 46a, the flat portion 46a whose upper surface faces the upstream side of the airflow is horizontal except for the lowermost flat portion 46a. The symbol H in the figure indicates a horizontal line.

On the flat portions 46a, the toner particles 47 in the air flow are put, so that the toner particles 47 are more reliably prevented from slipping off from the filter 46. This is the same even if the filter 46 is slightly inclined when the filter 46 is removed from the duct 41. In addition, of the flat part 46a whose upper surface faces the upstream side of the airflow,
The lowermost flat portion 46a is inclined from bottom to top as going from the upstream side to the downstream side. Even if the toner particles 47 slide down from here, the catch pan 52 catches the toner particles 47.

In order to prevent the toner particles 47 from slipping off, the upper surfaces of these flat portions 46a face the upstream side of the airflow.
It is more preferable that the slant is inclined from top to bottom as going from the upstream side to the downstream side. In order to make the orientation of the flat portion 46a sure, it is preferable to fix the side end of the filter 46 to the side plate 49 as shown in FIG.

(2) FIG. 7 shows another example. In the filter 46 shown in the figure, a rib 48 for preventing the toner particles 47 from sliding down is attached to the bent portion 46b on the upstream side of the airflow among the bent portions 46b. This rib 48
If it is the same as the resin-made reinforcing rib 48 shown in FIG. 5 (B), if it protrudes above the attached bent portion 46b to the extent that the gap between the flat portions 46a is appropriately provided. Good.

With such ribs 48, the toner particles 4
7 is more reliably prevented from slipping off the filter 46. Note that the rib 48 may be formed integrally with the connecting plate 50 shown in FIG. That is, the ribs 48 may be formed so as to span the opening 50a of the connection plate 50, and then the ribs 48 may be fixed to the filter 46.

(3) FIG. 8 is a modified example of the example of FIG.
In the same figure, ribs 58 for preventing the toner particles 47 from slipping down are provided at the bent portions 46b on the upstream side of the airflow of the filter 46. However, these ribs 58
Is formed of the same material as the filter medium of the filter 46, and is formed integrally with the filter 46 when the filter 46 is manufactured. Thereby, the forming process of the rib 58 can be simplified. In this example, it is preferable that both ends of the filter 46 be fixed to the side plate 49 shown in FIG.

(4) FIG. 9 shows still another example. In this example, among the flat portions 46a of the filter 46, the flat portion 46a whose lower surface faces the upstream side of the airflow is formed by the filter medium, but the flat portion 46a whose upper surface faces the upstream side of the airflow.
Is replaced by a catch pan 56 made of a non-porous material. The catch pan 56 is formed of, for example, metal or resin. Such a filter 46 is obtained by joining a catch pan 56 to a front end and a rear end of a flat portion 46a made of a filter material.

The front and rear ends of each catch pan 56 corresponding to the bent portion 46b of the filter 46 have toner particles 4
A rib 68 for preventing the 7 from falling off is integrally formed. However, the rib 68 may be formed only on the upstream side of the airflow. Also in this example, in order to prevent mutual movement of the flat portion 46a including the catch pan 56, the filter 46 is used.
Are preferably fixed to the side plate 49.

2. Second Embodiment FIG. 10 shows a toner collecting device 40 according to a second embodiment of the present invention. This toner collecting device 40 also has a duct 41 and a fan 45 similar to those of the first embodiment, and the toner particles 47 in the airflow are located upstream of the fan 45 in the horizontal central portion of the duct 41. Is provided. The filter 76 is formed by forming a filter material into a flat plate shape, and a plate 77,
78 is fixed. By this filter 76, the duct 41 is divided into two spaces of an upstream side and a downstream side, and air flows downstream through the filter 76,
The toner particles 47 do not flow downstream.

With the filter 76 installed inside the duct 41, the upper plate 77
Is pressed against the upper wall of the duct 41.
A side plate may be attached to the side of the filter. In this case, the upper plate 77 is pressed against the upper wall of the duct 41 by the elasticity of the side plate.
The lower plate 78 is fixed to a catch pan 82 made of metal or resin.

An opening 51 through which the filter 76 can be inserted and removed is formed in the bottom wall of the duct 41.
The catch pan 82 is engaged with the periphery of the opening 51. The catch pan 82 extends upstream and downstream of the airflow beyond the filter 76, and the vicinity of the upstream edge 82 a is bent so as to have a substantially inverted U-shaped cross section. Further, a groove 83 that opens to the upstream side is formed in the edge portion 82a. The upstream peripheral edge of the opening 51 is fitted into the groove 83. A packing 84 is fixed inside the groove 83 to prevent airflow from leaking.

The downstream edge portion 82b of the catch pan 82 is branched toward the downstream side, thereby forming a groove 85 opened to the downstream side. The peripheral edge on the downstream side of the opening 51 is fitted into the groove 85. The packing 8 is provided on the upper surface of the peripheral edge on the downstream side of the opening 51.
6 is fixed to prevent air flow from leaking. Thus, the catch pan 82 is engaged with the duct 41 with the filter 76 accommodated in the duct 41.
These grooves 83 and 85 are formed at the same height, and when the catch pan 82 is engaged with the duct 41, the catch pan 82 is arranged substantially horizontally. Here, the catch pan 82 is detachable from the duct 41 by bending a portion bent in an inverted U-shape near the edge portion 82a, thereby catching a large amount of the toner particles 47. The collected filters 76 can be replaced with new ones.

According to the above-described structure, the filter 76 has a flat plate shape and only stands upright on the catch pan 82, but the catch pan 82 extends to the upstream side of the air flow. For example, even when the toner particles 47 fall out of the filter 76 when the filter 76 is replaced, the toner particles 47 are received on the catch pan 82 and do not fall below it. Therefore, even in an image forming apparatus in which there is not enough space for vertically turning the duct 41, contamination inside and around due to falling of the toner particles 76 is reduced without complicating the structure. Further, the catch pan 82 is fixed below the filter 76, and the catch pan 82 is
A simple structure is required only to removably engage with No. 1 and does not cause a significant increase in manufacturing cost.

3. Third Embodiment FIG. 10 shows a toner collecting device 40 according to a third embodiment of the present invention. This toner collecting device also includes a duct 41 and a fan 45 similar to those of the first and second embodiments, but is omitted in FIG. Here, at the same position as in the above-described embodiment, a filter 96 for collecting the toner particles 47 in the air flow is provided.

The filter 96 has a bag type, that is, a bag shape, and is opened toward the upstream side of the air flow and closed at the downstream side. Upper 96a and lower 96 of filter 96
b is formed flat, and the lower part 96 b is fixed to the catch pan 52. Here, the catch pan 52
As in the first embodiment, it is detachably engaged with the bottom wall of the duct 41. When the catch pan 52 is attached to the bottom wall of the duct 41, the upper portion 96a of the filter 96
Due to the elasticity of the filter 96, the filter 96 is pressed against the upper wall of the duct 41. In this manner, the duct 41 is provided by the filter 96.
Is divided into two spaces, an upstream side and a downstream side. The air flows through the filter 96 to the downstream side, but the toner particles 47 are accumulated inside the filter 96 and do not flow to the downstream side. ing.

Here, the lower portion 96b of the filter 96 is wider than the filter 96, so that it is possible to accumulate a large amount of the toner particles 47 that have flowed into the filter 96 and collected. ing. Also, the lower 96
b extends upstream of the airflow beyond the upper part 96a,
This also enables a large amount of toner particles 47 to be accumulated. A frame may be attached to the opening on the upstream side of the bag-shaped filter 96 to reinforce the frame.

According to the above configuration, the bag-like filter 96 having the flat upper portion 96a and the lower portion 96b collects the toner particles 47 flowing inside the duct 41. Here, since the lower portion 96b is wider than the upper portion 96a of the filter 96, it is possible to reduce the occurrence of the toner particles 47 falling when the filter 96 is replaced, for example. Further, the lower portion 96b extends to the upstream side of the airflow from the upper portion 96a, so that the drop of the toner particles 47 is further reduced.

Accordingly, even in an image forming apparatus in which there is not enough space for vertically turning the duct 41, contamination of the inside and the surroundings due to the fall of the toner particles 47 is reduced without complicating the structure. Moreover, even if the duct 41 is oriented horizontally, the trapped amount can be increased because the toner particles 47 enter the bag-shaped filter 96. Further, the filter 96 can be formed in a bag shape and simply arranged as described above, which does not cause a significant increase in manufacturing cost.

4. Other Modifications (1) In the above embodiment, the filters 46, 76, and 96 are provided in the horizontal portion of the duct 41.
The present invention can be applied not only to a completely horizontal portion but also to a slightly inclined portion. (2) In the above embodiment, the filters 46, 76,
The catch pans 42, 52, and 92 also serve as lids for closing the openings 51.
An opening for taking in and out 76 and 96 may be formed, and this opening may be closed with a lid different from the catch pans 42, 52 and 92.

(3) The toner collecting device 40 of the above embodiment collects the floating toner generated when the toner is transferred from the developing unit 7 of the image forming unit to the photosensitive drum 2. The present invention is also applicable to an apparatus that collects residual toner dropped from the surface of the photosensitive drum 2 by a cleaning unit (for example, the cleaning blade 27 shown in FIG. 3) of the image forming unit.

[0057]

As described above, according to the present invention,
It is not necessary to orient the duct vertically, and it is possible to reduce or completely prevent toner particles from falling when the filter is replaced.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing a conventional toner collecting device, in which (A) shows a used state and (B) shows a disassembled state.

FIG. 2 is a side sectional view showing another example of a conventional toner collecting device.

FIG. 3 is a schematic side view showing an image forming section of an electrostatic copying machine which is an image forming apparatus using the toner collecting device according to the present invention.

FIGS. 4A and 4B are side cross-sectional views showing the toner collecting device according to the first embodiment of the present invention, wherein FIG.
Indicates a decomposition state.

FIGS. 5A, 5B, and 5C are perspective views each showing an example of a filter used in the toner collecting device shown in FIG. 4;

6 is a side sectional view showing a preferred example of a filter used in the toner collecting device shown in FIG.

7 is a side sectional view showing another preferred example of a filter used in the toner collecting device shown in FIG.

8 is a side sectional view showing another preferred example of a filter used in the toner collecting device shown in FIG.

9 is a side sectional view showing another preferred example of a filter used in the toner collecting device shown in FIG.

FIG. 10 is a side sectional view showing a toner collecting device according to a second embodiment of the present invention, wherein (A) is a use state,
(B) shows a decomposition state.

FIG. 11 is a side sectional view showing a filter of a toner collecting device according to a third embodiment of the present invention.

[Explanation of symbols]

40: toner collecting device, 41: duct, 42, 52: catch pan, 45: fan (air flow generating means), 46: filter, 46a: flat portion, 46b: bent portion, 47: toner particles, 48, 58 ... Rib, 56: Catch pan (flat portion), 68: Rib, 76: Filter, 82: Catch pan, 96: Filter, 96a: Upper part, 96b: Lower part

Claims (7)

[Claims] A duct through which toner particles floating from an image forming unit for electrostatically adhering toner to a sheet flows, and an airflow that generates a laterally flowing airflow inside the duct and causes the toner particles to flow. Generating means, and a filter which is exchangeably arranged inside the duct and collects the toner particles flowing by the air current, wherein the filter is bent in a zigzag pattern having alternating flat portions and bent portions. The flat portions are arranged one above the other so as to have an upper surface and a lower surface, respectively, and two bent portions sandwiching each of the flat portions are respectively located on the upstream side and the downstream side of the airflow. A toner collecting device for an image forming apparatus, wherein the toner collecting device is disposed. 2. The flat part of the flat part of the filter, the upper part of which faces the upstream side of the airflow is inclined substantially horizontally, or inclined from top to bottom from upstream to downstream. The toner collecting device for an image forming apparatus according to claim 1, wherein: 3. The filter according to claim 1, wherein at least the bent portion of the filter on the upstream side of the airflow is provided with a rib for preventing the toner particles from falling off. A toner collecting device for an image forming apparatus. 4. The flat part of the filter, the flat part of which the lower surface faces the upstream side of the airflow is formed of a filter medium, and the flat part whose upper surface faces the upstream side of the airflow is Wherein a rib for preventing the toner particles from dropping is provided integrally with the non-porous material at least at a bent portion on the upstream side of the air flow. Item 3. A toner collecting device for an image forming apparatus according to Item 1 or 2. 5. A duct into which toner particles floating from an image forming unit for electrostatically adhering toner to a sheet flow, and an airflow that generates a laterally flowing airflow inside the duct to flow the toner particles. Generating means, a filter that is exchangeably disposed inside the duct, and that captures the toner particles that are flowed by the airflow, and that is attached below the filter and detachably engages the duct. A catch pan disposed substantially horizontally, wherein the catch pan extends to the upstream side of the airflow from the filter. 6. A duct through which toner particles floating from an image forming unit for electrostatically adhering toner to a sheet flow, and an airflow that generates a laterally flowing airflow inside the duct to flow the toner particles. Generating means, and a filter which is exchangeably arranged inside the duct and collects the toner particles flowing by the air flow, wherein the filter is opened toward the upstream side of the air flow and downstream. A toner collecting device for an image forming apparatus, comprising: a bag-like shape closed by a flat portion, a flat upper portion and a lower portion, wherein the lower portion is wider than the upper portion. 7. The toner collecting device according to claim 6, wherein the lower portion extends further upstream than the upper portion of the airflow.