JP2017215533A - Powder conveying device and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress scattering of powder to the periphery of a receiving port that receives the powder compared with a case where conveyance of powder is performed without taking the influence of charging of the powder into consideration.SOLUTION: An image forming unit 30Y is provided with a unit-side storage part 342 that includes a toner discharge port 343 discharging a waste toner. A toner conveying mechanism 100 is provided with a body-side storage part 102 that is arranged below the unit-side storage part 342 and can be connected with or separated from the toner discharge port 343. The body-side storage part 102 includes a receiving port 103 that receives the waste toner discharged from the toner discharge port 343. The body-side storage part 102 is provided with a metal member 107 that is connected with a metal frame FL.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a powder conveying apparatus and an image forming apparatus.

Patent Document 1 includes a guide member that has an inclined surface that inclines toward the upstream side in the conveying direction as it goes downward with respect to the direction of gravity, and guides the powder conveyed by the conveying member along the inclined surface. It is disclosed.
Patent Document 2 discloses a cleaning device including a cleaning unit that electrostatically attracts residual toner to an applied portion by the action of a bias.

JP 2014-145865 A JP 2007-86386 A

In an apparatus for conveying powder, it is conceivable that the powder conveyed from the upstream side is received at a receiving port provided in the downstream conveying member, and the powder is further conveyed downstream. Here, if the powder is charged, it may be difficult for the powder to enter the receiving port. In this case, the powder is likely to be scattered around the receiving port.
An object of the present invention is to suppress the scattering of the powder around the receiving port for receiving the powder, as compared with the case where the powder is conveyed without considering the influence of the charging of the powder.

The invention according to claim 1 is used for conveying powder, and is arranged below the upstream conveying member having an outlet for discharging the powder and the upstream conveying member, and the exhaust. For downstream transport that can be connected to and separated from the outlet, and has a receiving port for receiving powder that has been discharged and dropped from the discharge port, at least part of which is made of metal and connected to the ground. And a member.
A second aspect of the present invention is the powder conveying apparatus according to the first aspect, wherein the metal portion of the downstream conveying member is provided at least at an opening edge of the receiving port.
According to a third aspect of the present invention, the portion of the downstream conveying member made of metal is provided in a portion of the downstream conveying member facing the upstream conveying member. The powder conveying apparatus according to 1 or 2.
According to a fourth aspect of the present invention, the upstream conveying member is detachable from the main body of the powder conveying device, and moves in one direction when mounted on the main body. The portion of the downstream conveying member that is mounted on the main body and made of metal is provided on the downstream side in the one direction with respect to the receiving port. This is a powder conveying device.
A fifth aspect of the present invention is the powder conveying apparatus according to the first aspect, wherein the metal portion of the downstream conveying member is located below the receiving port.
The invention according to claim 6 is used for conveying the powder, and is arranged below the upstream conveying member having an outlet for discharging the powder, the upstream conveying member, and the exhaust. Connected to and separated from the outlet, provided with a receiving port for receiving the powder that has been discharged and dropped from the discharge port, a downstream transport member used for powder transport, and an inside of the downstream transport member And a powder conveying member provided at least partially made of metal and connected to a ground to convey the powder.
The invention according to claim 7 is used for conveying powder, and is arranged below the upstream conveying member having an outlet for discharging the powder, the upstream conveying member, and the exhaust. For downstream conveyance that can be connected to and separated from the outlet, and has a receiving port for receiving powder that has been discharged and dropped from the discharge port, and at least part of which is formed of an antistatic material and is used for conveying powder And a member.
The invention according to claim 8 is used for conveying powder, and is arranged below the upstream conveying member having an outlet for discharging the powder, and below the upstream conveying member. It can be connected to and separated from the outlet, and has a receiving port for receiving the powder that has been discharged and dropped from the outlet, and at least a part thereof is formed of a resin having a surface resistivity of 1.0 × 10 ¹¹ Ω or less, And a downstream conveying member used for conveying powder.
The invention described in claim 9 comprises image forming means for forming an image on a recording material using powder, and a powder conveying device for conveying the powder, wherein the powder conveying device is claimed in claim 1. An image forming apparatus constituted by the powder conveyance device according to any one of 1 to 8.

According to the first aspect of the present invention, it is possible to suppress the scattering of the powder around the receiving port for receiving the powder as compared with the case where the powder is conveyed without considering the influence of the charging of the powder.
According to the second aspect of the present invention, it is possible to suppress the receiving port from being clogged with the powder as compared with the case where the metal portion is not provided at the opening edge of the receiving port.
According to invention of Claim 3, compared with the case where the part which consists of metals in the part which opposes the upstream conveyance member among the downstream conveyance members is not provided, the downstream conveyance member and the upstream conveyance It is possible to suppress the floating of the powder between the members.
According to invention of Claim 4, the area | region where powder disperses can be reduced compared with the case where the part which consists of a metal is provided in the part located in an upstream in one direction rather than a receiving port.
According to the fifth aspect of the present invention, it becomes easier to move the powder toward the inside of the downstream conveying member.
According to the sixth aspect of the present invention, it is possible to suppress the scattering of the powder around the receiving port for receiving the powder as compared with the case where the powder is conveyed without considering the influence of the charging of the powder.
According to the seventh aspect of the present invention, it is possible to suppress the scattering of the powder around the receiving port for receiving the powder as compared with the case where the powder is conveyed without considering the influence of the charging of the powder.
According to the eighth aspect of the present invention, it is possible to suppress the scattering of the powder around the receiving port for receiving the powder as compared with the case where the powder is conveyed without considering the influence of the charging of the powder.
According to the ninth aspect of the present invention, it is possible to suppress the scattering of the powder around the receiving port for receiving the powder, as compared with the case where the powder is conveyed without considering the influence of the charging of the powder.

1 is a diagram illustrating a configuration of an image forming apparatus. FIG. 4 is a diagram illustrating a rear side portion of the image forming unit and a toner transport mechanism. FIG. 4 is an enlarged view of a rear side portion of the image forming unit and a toner transport mechanism. FIG. 6 is a diagram illustrating a comparative example of an image forming unit and a toner transport mechanism. (A) and (B) are diagrams showing the behavior of waste toner in a comparative example. FIG. 6 is a diagram for explaining the behavior of waste toner in the present embodiment. (A) and (B) are diagrams showing another configuration example of the toner transport mechanism. It is the figure which showed the other structural example of the main body side accommodating part, Comprising: It is a figure at the time of seeing a main body side accommodating part from upper direction. (A) and (B) are diagrams showing another configuration example of the toner transport mechanism. It is the figure which showed the state of the receiving surface. It is the figure which showed the experimental result.

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.
FIG. 1 is a diagram illustrating a configuration of an image forming apparatus according to the present embodiment.
The image forming apparatus 1 of the present embodiment includes a paper feed unit 1A, a printing unit 1B, and a paper discharge unit 1C.
The paper feed unit 1A includes a first paper storage unit 11 to a fourth paper storage unit 14 that store paper as an example of a recording material, and is stored in the first paper storage unit 11 to the fourth paper storage unit 14. The paper is supplied to the printing unit 1B.

The printing unit 1B forms an image on the paper supplied from the paper supply unit 1A. The printing unit 1B is provided with an image forming process unit 20 that forms an image on a sheet and a control unit 21 that controls the image forming process unit 20.
The printing unit 1B is further provided with an image processing unit 22. The image processing unit 22 performs image processing on image data transmitted from, for example, the image reading device 4 or the personal computer (PC) 5.
The printing unit 1B includes a touch panel or the like, and is provided with a UI (User Interface) 23 that displays information to the user and receives information from the user.

An image forming process unit 20 as an example of an image forming unit includes six image forming units 30T, 30P, 30Y, 30M, 30C, and 30K (hereinafter simply referred to as “image forming units”) arranged in parallel at a predetermined interval. 30 ”).
Each image forming unit 30 can be attached to and detached from the unit main body 120 of the printing unit 1B. By pulling the image forming unit 30 in the direction perpendicular to the paper surface of FIG. Each image forming unit 30 can be detached from the section 120.

In other words, in the present embodiment, each image forming unit 30 can be removed by pulling the image forming unit 30 toward the front side of the printing unit 1B.
Further, the image forming units 30 can be attached to the printing unit 1B by pushing the image forming units 30 toward the rear side of the printing unit 1B.

Each image forming unit 30 includes a photosensitive drum 31 on which an electrostatic latent image is formed while rotating in the direction of arrow A, a charging roll 32 that charges the photosensitive drum 31, and an electrostatic formed on the photosensitive drum 31. A developing unit 33 for developing the latent image and a drum cleaner 34 for removing untransferred toner and the like on the surface of the photosensitive drum 31 are provided.
Further, the image forming process section 20 is provided with a laser exposure device 26 that scans and exposes the photosensitive drum 31 provided in each of the image forming units 30T, 30P, 30Y, 30M, 30C, and 30K with laser light. .

Each image forming unit 30 is configured in substantially the same manner except for the toner stored in the developing device 33.
In each of the image forming units 30Y, 30M, 30C, and 30K, yellow (Y), magenta (M), cyan (C), and black (K) toner images are formed. Further, in the image forming units 30T and 30P, a toner image of a special color such as a corporate color or a clear toner image is formed.

Further, the image forming process unit 20 is provided with an intermediate transfer belt 41 to which toner images of respective colors formed on the photosensitive drums 31 of the respective image forming units 30 are transferred in a multiple manner.
Further, the image forming process unit 20 is provided with a primary transfer roll 42 that transfers (primary transfer) each color toner image of each image forming unit 30 to the intermediate transfer belt 41 in the primary transfer unit T1.

In addition, the image forming process unit 20 is provided with a secondary transfer roll 40 that collectively transfers (secondary transfer) the superimposed toner image transferred onto the intermediate transfer belt 41 to a sheet at the secondary transfer unit T2. ing.
Further, the image forming process unit 20 is provided with a belt cleaner 45 that removes untransferred toner and the like on the surface of the intermediate transfer belt 41, and a fixing device 80 that fixes the secondary transferred image onto the sheet.

In the image forming apparatus 1, first, image data output from the image reading device 4 or the PC 5 is supplied to the image processing unit 22, and the image processing unit 22 performs image processing on the image data. The image data subjected to the image processing is supplied to the laser exposure device 26.
Then, the laser exposure device 26 irradiates each photosensitive drum 31 with laser light modulated with the image data obtained from the image processing unit 22. Thereby, an electrostatic latent image is formed on each photosensitive drum 31.

The formed electrostatic latent image is developed by the developing device 33, and a toner image of each color is formed on the photosensitive drum 31. The formed color toner images are sequentially electrostatically transferred (primary transfer) by the primary transfer roll 42 onto the intermediate transfer belt 41 rotating in the direction of arrow C in FIG. 1 and superimposed on the intermediate transfer belt 41. A toner image is formed.
The superimposed toner image formed on the intermediate transfer belt 41 is conveyed to the secondary transfer portion T2 in which the secondary transfer roll 40 and the backup roll 49 are disposed as the intermediate transfer belt 41 moves.

On the other hand, for example, the sheet is taken out from the first sheet storage unit 11 by the delivery roll 15 and conveyed to the position of the registration roll 74.
When the superimposed toner image is conveyed to the secondary transfer portion T2, the sheet is supplied from the registration roll 74 to the secondary transfer portion T2 in accordance with the timing.
Then, the superimposed toner image is electrostatically transferred (secondary transfer) onto the sheet by the action of the transfer electric field formed between the secondary transfer roll 40 and the backup roll 49 at the secondary transfer portion T2. .

Thereafter, the sheet on which the superimposed toner image is electrostatically transferred is peeled off from the intermediate transfer belt 41 and conveyed to the fixing device 80. In the fixing device 80, a heating process and a pressurizing process are performed on the sheet, and the superimposed toner image is fixed on the sheet.
The paper on which the fixed image is formed passes through a curl correction unit 81 provided in the paper discharge unit 1C and is then conveyed to a paper stacking unit (not shown).

In this embodiment, untransferred toner or the like remaining on the photosensitive drum 31 after the primary transfer is removed by the drum cleaner 34 disposed on the downstream side of the primary transfer roll 42.
The drum cleaner 34 is provided with a cleaning blade (not shown) that is pressed against the photosensitive drum 31, and the cleaning blade removes untransferred toner and the like as an example of powder remaining on the photosensitive drum 31. Is done.

The drum cleaner 34 is provided with a unit-side conveying member 341 that conveys the removed untransferred toner (hereinafter referred to as “waste toner”). The unit-side transport member 341 is disposed along the axial direction of the photosensitive drum 31, and transports the waste toner to the rear side (back side) of the printing unit 1B.
The waste toner conveyed to the rear side of the printing unit 1B is supplied to a toner conveying mechanism 100 (not shown in FIG. 1, which will be described later) provided on the rear side of the printing unit 1B. The waste toner is sent to a container (not shown) by the toner transport mechanism 100.
Here, the unit side conveyance member 341 provided in the drum cleaner 34 and the portion where the toner conveyance mechanism 100 is provided can be regarded as a powder conveyance device that conveys powder.

FIG. 2 is a diagram illustrating the rear side portion of the image forming unit 30Y and the toner transport mechanism 100. More specifically, FIG. 2 is a cross-sectional view of the image forming unit 30Y and the toner transport mechanism 100 taken along line II-II in FIG.
In FIG. 2, the configuration of the image forming unit 30Y will be described as an example, but the other image forming units 30 are configured in the same manner as the image forming unit 30Y.

As shown in FIG. 2, the image forming unit 30Y is provided with a unit-side transport member 341. The unit-side transport member 341 is disposed along the longitudinal direction of the image forming unit 30Y, and transports waste toner generated in the image forming unit 30Y to the rear side of the printing unit 1B.
The unit-side conveying member 341 includes a rotation shaft 341A and a protruding portion 341B that protrudes from the outer peripheral surface of the rotation shaft 341A and is formed in a spiral shape, and rotates around the rotation shaft 341A to print waste toner. Transport to the rear side of unit 1B.

The image forming unit 30Y is further provided with a cylindrical unit-side housing portion 342 that houses the unit-side transport member 341.
The unit side accommodating portion 342 as an example of the upstream side conveying member is used for conveying waste toner together with the unit side conveying member 341, and supplies the waste toner to the toner conveying mechanism 100 located on the downstream side.

A toner discharge port 343 is provided at one end portion (one end portion located on the rear side) in the longitudinal direction of the unit side accommodating portion 342.
The toner discharge port 343 is provided in the lower part (bottom part) of the unit-side accommodation part 342. In the present embodiment, when the waste toner transported by the unit-side transport member 341 reaches the toner discharge port 343, the waste toner falls downward through the toner discharge port 343.

A toner conveyance mechanism 100 is provided below the image forming unit 30 (below the toner discharge port 343).
The toner conveyance mechanism 100 is provided with a main body side conveyance member 101. The main body side conveyance member 101 further conveys the waste toner discharged from the toner discharge port 343 (falling waste toner) to the rear side of the printing unit 1B. The main body side conveyance member 101 includes the rotation shaft 101A and the rotation shaft 101A. A protruding portion 101B that protrudes from the outer peripheral surface of the shaft 101A and is formed in a spiral shape, and rotates around the rotating shaft 101A to convey waste toner to the rear side of the printing unit 1B.

Further, the toner conveyance mechanism 100 is provided with a main body side accommodation portion 102 that accommodates the main body side conveyance member 101.
The main body side accommodating portion 102 as an example of a downstream side conveying member is disposed on the downstream side of the unit side accommodating portion 342 in the waste toner conveying direction, and receives the waste toner from the unit side accommodating portion 342. Moreover, the main body side accommodating part 102 is formed in a cylindrical shape like the unit side accommodating part 342, and is further arranged along the horizontal direction.

A receiving port 103 that receives waste toner discharged from the image forming unit 30 </ b> Y (unit-side container 342) is provided at one end in the longitudinal direction of the main body-side container 102 (one end located on the front side). . The receiving port 103 is provided in the upper part of the main body side accommodating portion 102.
Waste toner discharged from the image forming unit 30 is supplied to the main body side conveyance member 101 through the receiving port 103. The waste toner is transported toward the storage container (not shown) by the main body side transport member 101.

  Here, in the present embodiment, the main body side accommodating portion 102 is disposed below the unit side accommodating portion 342. Moreover, the unit side accommodating part 342 and the main body side accommodating part 102 are arrange | positioned so that a connection and separation | spacing are mutually possible. In this embodiment, the toner discharge port 343 and the receiving port 103 can be connected and separated via the seal member 105.

  The seal member 105 is disposed so as to surround the toner discharge port 343 and the reception port 103, and suppresses waste toner from being scattered around the toner discharge port 343 and the reception port 103. The seal member 105 is fixed to the main body side accommodating portion 102.

FIG. 3 is an enlarged view of the rear side portion of the image forming unit 30Y and the toner transport mechanism 100. In FIG. 3, illustration of the seal member 105 is omitted. Further, in each of the drawings after FIG. 4, the illustration of the seal member 105 is also omitted.
As shown in FIG. 3, a metal member 107 that extends along the axial direction of the main body side housing portion 102 and has electrical conductivity is attached to the upper portion (upper surface) of the main body side housing portion 102. The metal member 107 is formed by bending a sheet metal.
Further, the toner conveying mechanism 100 is provided with a metal screw 108 for fixing the metal member 107 to the main body side accommodating portion 102.

A metal frame (apparatus frame) FL (frame ground) extending along the vertical direction is provided on the rear side of the printing unit 1B.
In the present embodiment, one end portion (rear end portion) of the metal member 107 is fixed to the metal frame FL by the metal screw 108. In other words, in the present embodiment, the metal member 107 is electrically connected to the metal frame FL. More specifically, the metal member 107 is connected (grounded) to the ground.

The metal member 107 is provided on the rear side of the printing unit 1 </ b> B with respect to the receiving port 103. Further, a rear side portion of the metal member 107 is fixed to the main body side accommodating portion 102 by a metal screw 108.
Furthermore, the metal member 107 extends to the receiving port 103 starting from a location where the metal screw 108 is provided. Further, the metal member 107 reaches the opening edge 103 </ b> A of the receiving port 103 and further reaches the inner wall 103 </ b> B of the receiving port 103.
When the metal member 107 is provided as in this embodiment, clogging of waste toner at the receiving port 103 is suppressed, and scattering of waste toner around the receiving port 103 is suppressed (details will be described later).

FIG. 4 is a diagram showing a comparative example of the image forming unit 30Y and the toner transport mechanism 100.
In this comparative example, the metal member 107 shown in FIG. 3 is not provided.
Also in this comparative example, waste toner sequentially falls from the toner discharge port 343, and the waste toner is supplied to the main body side conveyance member 101 through the receiving port 103. The waste toner is transported to a storage container (not shown) by the main body side transport member 101.
In this comparative example, waste toner adheres to the inner wall 103B of the receiving port 103, and the receiving port 103 is likely to be blocked by the waste toner. In this comparative example, waste toner is likely to be scattered around the receiving port 103.

5A and 5B are diagrams showing the behavior of waste toner in the comparative example.
5A and 5B show the behavior of waste toner in a state where the function of the seal member 105 (see FIG. 2) has deteriorated over time.
In other words, the seal member 105 deteriorates with time. In this case, the sealing performance is lowered, and the waste toner can be moved around the toner discharge port 343 and the receiving port 103.

In this comparative example, as shown in FIG. 5A, the waste toner is transported in the unit side accommodating portion 342. At this time, for example, the waste toner is negatively charged (becomes negative polarity) by frictional charging. ), The unit side accommodating portion 342 is positively charged (becomes positive polarity).
After that, the waste toner is transported in the main body side accommodating portion 102. In this case as well, the waste toner is similarly charged negatively and the main body side accommodating portion 102 is positively charged.

In this comparative example, as the waste toner is conveyed, the waste toner, the unit-side storage unit 342, and the main body-side storage unit 102 are gradually charged, and as described above, the waste toner is negatively charged, and the unit-side storage unit 342, the main body side accommodating portion 102 is positively charged.
In this state, when new waste toner is transported from the upstream side, the waste toner adheres to the inner wall 103B of the receiving port 103 by electrostatic force as shown in FIG.
Further, as shown in FIG. 5A, the waste toner adheres to the outer peripheral surface of the unit-side storage unit 342 and the outer peripheral surface of the main body-side storage unit 102.

When the waste toner is further transported, as shown in FIG. 5B, the amount of waste toner adhering to the inner wall 103B of the receiving port 103 increases. It will be blocked.
In the comparative example, the waste toner that does not go to the receiving port 103 moves to the front side as indicated by an arrow 5A in FIG.
Specifically, it moves to a space located between the unit side accommodating portion 342 and the main body side accommodating portion 102 and located further to the front side than the receiving port 103 (hereinafter, “front side space FS”). To do.

Further, the waste toner that does not go to the receiving port 103 also moves to the rear side as indicated by an arrow 5B in FIG.
Specifically, it is a space located between the unit side accommodation portion 342 and the main body side accommodation portion 102 and moved to a space located on the rear side of the receiving port 103 (hereinafter referred to as “rear side space RS”). To do.

At this time, in this comparative example, the negatively charged waste toner has already adhered to the outer peripheral surface of the unit-side container 342 and the outer peripheral surface of the main body-side container 102.
As a result, in this comparative example, between the new waste toner that has moved to the front space FS and the waste toner that has already adhered to the outer peripheral surface of the unit-side storage unit 342 and the outer peripheral surface of the main-unit storage unit 102. The new waste toner that has been repelled and moved to the front space FS is likely to float. Then, the new waste toner does not adhere to the unit side accommodating portion 342 and the main body side accommodating portion 102 but scatters to the front side.

  Similarly, in the rear side space RS, the new waste toner that has moved to the rear side space RS and the waste toner that has already adhered to the outer peripheral surface of the unit-side storage unit 342 and the outer peripheral surface of the main unit-side storage unit 102. Thus, a repulsive force is generated, and the new waste toner that has moved to the rear side space RS is likely to float. Then, the new waste toner does not adhere to the unit-side container 342 and the main body-side container 102 but scatters to the rear side.

Here, when the waste toner does not adhere to the outer peripheral surfaces of the unit side accommodating portion 342 and the main body side accommodating portion 102, the waste toner moved to the front side space FS and the rear side space RS adheres to the outer peripheral surface. Thus, the scattering of waste toner can be suppressed.
However, if the waste toner adheres to the unit-side container 342 or the main body-side container 102, a repulsive force is generated between the adhered waste toner and the newly supplied waste toner, and the newly supplied waste toner. Will float and move farther.
In this case, the waste toner adheres to a wider area in the printing unit 1B. Also, waste toner adheres to the outer surface of the image forming unit 30Y.

Further, in the comparative example shown in FIG. 5, both the unit side accommodation portion 342 and the main body side accommodation portion 102 are positively charged, and there is a potential between the unit side accommodation portion 342 and the main body side accommodation portion 102. Gradient is less likely to occur.
When a potential gradient occurs, waste toner is attracted to either the unit-side container 342 or the main body-side container 102, and the waste toner is less likely to float, but in the comparative example, this potential gradient is unlikely to occur. As described above, waste toner tends to float.

FIG. 6 is a diagram for explaining the behavior of waste toner in the present embodiment.
In the present embodiment, as described above and as shown in FIG. 6, the metal member 107 connected to the ground is provided, whereby the opening edge 103 </ b> A of the receiving port 103 (the rear side of the opening edge 103 </ b> A) is provided. Part) is suppressed from being positively charged.

  In this case, the waste toner hardly adheres to the opening edge 103A of the receiving port 103. In addition, when the waste toner comes into contact with the opening edge 103A (the portion of the opening edge 103A located on the rear side), the waste toner is relieved and the waste toner hardly adheres to the opening edge 103A. In this case, the receiving port 103 is suppressed from being blocked by the toner.

Furthermore, in this embodiment, the falling direction of the waste toner that has dropped from the toner discharge port 343 is not directly below, but is obliquely downward as indicated by an arrow 6A.
More specifically, the waste toner falls obliquely toward the metal member 107. More specifically, the metal member 107 is provided on the rear side with respect to the receiving port 103, and the waste toner dropped from the toner discharge port 343 moves to the rear side. Accordingly, in the present embodiment, the front side space FS. Waste toner that moves to

In the present embodiment, the metal member 107 is not provided on the front side portion of the opening edge 103A of the receiving port 103 (hereinafter referred to as “front side portion”), as shown in FIG. In addition, negatively charged waste toner adheres to the front side portion.
In this embodiment, a potential gradient indicated by an arrow 6B is generated between the waste toner adhering to the metal member 107, and new waste toner that has fallen due to this potential gradient is directed toward the metal member 107. Moving. More specifically, the waste toner that has fallen from the toner discharge port 343 does not fall straight, but falls obliquely downward as indicated by an arrow 6A and travels toward the metal member 107.

In this case, the amount of waste toner that moves toward the front space FS is reduced, and the area where the waste toner adheres in the printing unit 1B is reduced.
In the printing unit 1B of this embodiment, the space located on the front side of the receiving port 103 is wider than the space located on the rear side of the receiving port 103, and waste toner moves to the front space FS side. As a result, the area where the waste toner adheres expands.

As shown in FIG. 2, there is an image forming unit 30Y on the front side of the receiving port 103, and when waste toner moves to the front space FS (not shown in FIG. 2), it is discarded in the image forming unit 30Y. The toner tends to adhere.
In contrast, in the configuration of the present embodiment, the waste toner moves toward the metal member 107 (the waste toner moves toward the rear side of the printing unit 1B), and the waste toner moves toward the front side of the printing unit 1B. Movement is suppressed. As a result, the area where the waste toner adheres is reduced, and the adhesion of the waste toner to the image forming unit 30Y is also suppressed.

More specifically, the image forming unit 30Y of this embodiment is detachable from the unit main body 120 (see FIG. 1) of the printing unit 1B, and the image forming unit 30Y is attached to the unit main body 120. At this time, the image forming unit 30Y moves in the rear direction, which is one direction, and the image forming unit 30Y is attached.
In the present embodiment, the metal member 107 is provided on the downstream side in one direction with respect to the receiving port 103, and the image forming unit 30 </ b> Y whose most part is located on the upstream side in one direction with respect to the receiving port 103. , Waste toner becomes difficult to adhere.

Furthermore, in the present embodiment, as shown by an arrow 6E in FIG. 6, a potential gradient is generated between the unit side housing portion 342 and the main body side housing portion 102 in the rear side space RS.
In addition, in the present embodiment, the metal member 107 (the portion having electrical conductivity in the main body side housing portion 102) is provided in a portion of the main body side housing portion 102 that faces the unit side housing portion 342. Therefore, a potential gradient is generated between the unit-side container 342 and the main body-side container 102 (between the waste toner adhering to the outer peripheral surface of the unit-side container 342 and the metal member 107).
As a result, the waste toner easily moves toward the metal member 107 in the rear side space RS, and the waste toner is prevented from floating in the rear side space RS. In this case, the movement of the waste toner to the rear side of the printing unit 1B (the movement of the waste toner further to the rear side than the rear side space RS) can be suppressed.

In addition, although the case where the metal member 107 comprised by the sheet metal was used was demonstrated above, not only the metal member 107 but the plating process is performed with respect to the main body side accommodating part 102, for example, and the surface of the main body side accommodating part 102 is used. A metal film may be formed.
In the above description, the metal member 107 is installed on the rear side of the receiving port 103, but the installation location of the metal member 107 is not limited to the rear side of the receiving port 103.
For example, as shown in FIG. 7A (a diagram showing another configuration example of the toner transport mechanism 100), the metal member 107 may be installed on the front side of the receiving port 103.
Although illustration is omitted, the metal member 107 located on the front side is also connected to the metal frame FL (see FIG. 3) via a member (not shown) having electrical conductivity.

In the case of the configuration example shown in FIG. 7A, a potential gradient is generated between the unit-side container 342 and the main body-side container 102 in the front-side space FS, thereby suppressing waste toner from floating in the front-side space FS. It is done.
In the case of the configuration example shown in FIG. 7A, the waste toner discharged from the toner discharge port 343 falls obliquely downward as described above. Specifically, the waste toner moves toward the front side where the metal member 107 is located.

Further, as shown in FIG. 7B, metal members 107 may be installed on both the rear side of the receiving port 103 and the front side of the receiving port 103.
In this case, a potential gradient is generated between the unit side housing portion 342 and the main body side housing portion 102 in both the front side space FS and the rear side space RS, and both the front side space FS and the rear side space RS are present. Therefore, the floating of waste toner can be suppressed.

FIG. 8 is a view showing another configuration example of the main body side accommodating portion 102 and is a view when the main body side accommodating portion 102 is viewed from above.
Also in this configuration example, the metal member 107 is provided on the upper surface of the main body side accommodating portion 102.
Specifically, in this configuration example, the metal members 107 are provided not only on the rear side of the receiving port 103 and on the front side of the receiving port 103 but also on both sides of the receiving port 103.
In other words, the metal member 107 is also provided in a portion located on both sides of the receiving port 103 and in a portion positioned beside the receiving port 103 in the circumferential direction of the main body side housing portion 102.
As described above, the metal member 107 may be provided not only on the rear side and the front side of the receiving port 103 but also on a side portion of the receiving port 103.

Further, in the above, by providing the metal member 107, the electric charge accumulated in the main body side accommodating portion 102 is released to the metal frame FL. However, the surface resistivity of the main body side accommodating portion 102 itself is 1.0 × 10 ¹¹ Ω or less. You may form with resin of.

As a resin having a surface resistivity of 1.0 × 10 ¹¹ Ω or less, an antistatic flame-retardant AEPDS (acrylonitrile-ethylene-propylene-diene-styrene plastic) molding material (surface resistivity 1. 0 × 10 ^{5 to} 1.0 × 10 ¹¹ Ω (based on ASTM D257, test conditions are 1000 V, 2.5 mmt)), conductive POM (surface resistivity 10 × 10 ² Ω (based on IEC 60093)), etc. Is mentioned.
When the antistatic flame retardant AEPDS having a surface resistivity of 1.0 × 10 ^{5 to} 1.0 × 10 ¹¹ Ω is used, charging of the main body side housing portion 102 itself is suppressed. It is not necessary to connect the side accommodating part 102.
In the case of using a resin having higher conductivity, that is, lower surface resistivity, the main body side accommodating portion 102 is connected to the metal frame FL and grounded as necessary.

In addition, the formation of the main body side accommodating portion 102 using the antistatic material is not limited to the entire main body side accommodating portion 102 being formed of the antistatic material. For example, only a part of the main body side accommodating portion 102 is formed. You may form with an antistatic material.
Specifically, for example, as in the form shown in FIG. 3, only the portion from the opening edge 103 </ b> A of the receiving port 103 toward the rear side may be formed of an antistatic material. Further, for example, similarly to the embodiment shown in FIG. 8, the portion around the receiving port 103 may be formed of an antistatic material.

FIGS. 9A and 9B are diagrams showing another configuration example of the toner transport mechanism 100. FIG.
In the configuration example shown in FIG. 9A, a main body side conveying member 101 as an example of a powder conveying member is formed of a metal material, and the main body side conveying member 101 is formed on a metal frame FL (see FIG. 3). It is electrically connected to it.
In this configuration example, as indicated by an arrow 9A, a potential gradient is generated between the waste toner attached to the opening edge 103A of the receiving port 103 and the main body side conveyance member 101.
In this case, the new waste toner supplied to the receiving port 103 is attracted to the main body side conveyance member 101 by this potential gradient. Also in this case, waste toner is suppressed from being collected in the receiving port 103, and clogging of the receiving port 103 is suppressed.

  The formation of the main body side conveying member 101 with metal is not limited to the whole main body side conveying member 101 being made of metal, but the main body side conveying member 101 may be formed by, for example, forming only the rotation shaft 101A with metal. A part of may be formed of a material having electrical conductivity.

Further, as shown in FIG. 9B, a metal member 107 may be provided in a portion (a bottom portion of the main body side housing portion 102) located below the receiving port 103 in the main body side housing portion 102.
In other words, a member having electrical conductivity is installed in a portion of the main body side accommodating portion 102 located on the opposite side of the receiving port 103 with the main body side conveying member 101 interposed therebetween, or electrical conductivity is imparted. May be.
Also in this case, the member having electrical conductivity and the portion having electrical conductivity are electrically connected to the metal frame FL (see FIG. 3).

In the configuration example shown in FIG. 9B, as indicated by an arrow 9B, between the waste toner adhering to the opening edge 103A of the receiving port 103 and a member having electrical conductivity or a portion having electrical conductivity, A potential gradient occurs.
Also in this case, similarly to the above, the new waste toner supplied to the receiving port 103 is attracted to the bottom portion of the main body side accommodating portion 102 by this potential gradient. As a result, similarly to the above, waste toner is prevented from accumulating in the receiving port 103, and clogging of the receiving port 103 is suppressed.

(Experimental example)
The inventor conducted experiments on the amount of waste toner scattered in the following six aspects.
(1) A mode of the comparative example shown in FIGS. 4 and 5 (2) A mode in which a metal member 107 is provided on the upper surface of the main body side accommodating portion 102 shown in FIG. 8 (3) A mode shown in FIG. A mode in which the metal member 107 is provided on the rear side of the receiving port 103 (4) A mode in which the metal member 107 is provided on the front side of the receiving port 103 shown in FIG.

The experimental conditions will be described. In each of the above aspects (1) to (4), waste toner was conveyed for 1 minute. Further, the waste toner was transported without installing the seal member 105 (see FIG. 2). Further, a receiving surface along the horizontal direction was installed below the receiving port 103 and at a position 30 cm away from the receiving port 103, and the waste toner falling from above was received on this receiving surface.
The area of the receiving surface where the waste toner adhered was measured. Specifically, the waste toner adheres to the receiving surface, for example, as shown in FIG. 10 (showing the state of the receiving surface), but the area of the portion of the receiving surface where the waste toner is attached. Was measured.

FIG. 11 shows the experimental results.
As shown in FIG. 11 (1), in the aspect of the comparative example, the amount of waste toner scattered was large, and the area of the portion where the waste toner adhered was about 136 mm ² .
On the other hand, in the aspects (2) to (4), which are aspects of the present embodiment, the adhesion area of the waste toner is significantly reduced as compared with the aspect of the comparative example.

In the aspect (4) (the aspect in which the metal member 107 is provided on the front side of the receiving port 103), as described above, the waste toner easily moves to the front side of the printing unit 1B. The adhesion area increases.
In addition, in the aspect (4), waste toner easily moves to the area indicated by reference numeral 2X in FIG. 2, but there is no member for receiving the waste toner from below, and waste toner adheres to this area. The area becomes larger. However, this adhesion area is overwhelmingly small compared with the aspect of the comparative example of (1).

(Other)
In the embodiment described above, the metal member 107 is installed on the portion that transports the waste toner to suppress the scattering of the waste toner around the receiving port 103. The configuration may also use locations other than waste toner conveyance.
For example, if each of the components described above is provided in the process of transporting toner from a toner cartridge (not shown) to each image forming unit 30, toner scattering can be similarly suppressed.

DESCRIPTION OF SYMBOLS 1 ... Image formation apparatus, 20 ... Image formation process part, 100 ... Toner conveyance mechanism, 101 ... Main body side conveyance member, 102 ... Main body side accommodating part, 103 ... Reception port, 103A ... Opening edge, 107 ... Metal member, 341 ... Unit side conveying member, 342... Unit side accommodating portion, 343... Toner discharge port, FL.

Claims (9)

An upstream conveying member that is used for conveying powder and has a discharge port for discharging the powder;
It is disposed below the upstream conveying member, and can be connected to and separated from the discharge port, and has a receiving port for receiving the powder that has been discharged from the discharge port and dropped, and at least a part thereof is made of metal and is grounded. A downstream conveying member used for conveying powder,
A powder conveying apparatus comprising:   The powder conveying apparatus according to claim 1, wherein a portion of the downstream conveying member made of metal is provided at least at an opening edge of the receiving port.   3. The powder conveyance according to claim 1, wherein the portion of the downstream conveyance member made of metal is provided in a portion of the downstream conveyance member facing the upstream conveyance member. apparatus. The upstream conveying member is detachable with respect to the main body of the powder conveying device, and when attached to the main body, moves in one direction and is attached to the main body.
The powder conveying apparatus according to any one of claims 1 to 3, wherein a portion of the downstream conveying member made of metal is provided downstream of the receiving port in the one direction.   The powder conveying apparatus according to claim 1, wherein a portion made of metal in the downstream conveying member is located below the receiving port. An upstream conveying member that is used for conveying powder and has a discharge port for discharging the powder;
A downstream which is disposed below the upstream conveying member and which can be connected to and separated from the discharge port, and which accepts the powder discharged and dropped from the discharge port, and used for conveying the powder A side conveying member;
A powder conveying member provided inside the downstream conveying member, at least part of which is made of metal and connected to a ground, and conveys powder;
A powder conveying apparatus comprising: An upstream conveying member that is used for conveying powder and has a discharge port for discharging the powder;
The material is provided below the upstream conveying member and can be connected to and separated from the discharge port. The receiving port receives the powder discharged from the discharge port and dropped, and at least a part of the antistatic material. Formed on the downstream side and used for conveying powder;
A powder conveying apparatus comprising: An upstream conveying member that is used for conveying powder and has a discharge port for discharging the powder;
The receiving port is disposed below the upstream conveying member and can be connected to and separated from the discharge port. The receiving port receives the powder discharged and dropped from the discharge port, and at least a part of the surface resistivity. Is formed of a resin of 1.0 × 10 ¹¹ Ω or less, and is used for conveying the powder on the downstream side,
A powder conveying apparatus comprising:   The powder according to any one of claims 1 to 8, further comprising: an image forming unit that forms an image on a recording material using powder; and a powder transport device that transports the powder. An image forming apparatus configured by a body conveyance device.

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