JP5614702B2 - Toner transport device, cleaning device, and image forming apparatus - Google Patents

Description

  The present invention relates to a toner conveying device that conveys toner, a cleaning device including the toner conveying device, and an image forming apparatus.

  In image forming apparatuses such as copiers, printers, facsimiles, and multi-function machines, a process unit in which an image carrier and a developing device are unitized, and a waste toner box as a waste toner collection unit are provided for convenience of maintenance. Therefore, it is often attached to the image forming apparatus main body so as to be detachable. Therefore, for example, in the image forming apparatus described in Patent Document 1, a shutter that opens and closes the toner inlet in order to prevent toner from leaking from the toner inlet provided in the process unit when the process unit is detached. A member is provided. Further, here, the shutter member is configured so as to be slid and opened and closed in the toner conveyance path in accordance with the attaching / detaching operation of the process unit. The toner is scraped off by a shutter member that slides the toner so that the toner is not scattered outside the process unit.

  Incidentally, in recent years, the toner used in the image forming apparatus has been reduced in particle size for the purpose of improving the image quality, and the melting point has been lowered in order to improve the productivity of image printing. On the other hand, the fluidity of the toner tends to decrease as the particle size is reduced and the melting point is lowered. For this reason, the toner stays or adheres in the conveyance path, resulting in toner conveyance failure or clogging. It's getting easier.

  In the image forming apparatus described in Patent Document 1, the toner in the toner conveyance path is scraped off by the sliding shutter member. However, when the process unit is used without being removed for a long period of time, the shutter Since the sliding movement of the member is not performed over a long period of time, there is a possibility that the toner stays and adheres between the shutter member and the inner surface of the conveyance path, and the toner conveyance is hindered.

  In view of such circumstances, an object of the present invention is to provide a toner transport device capable of transporting toner without staying in the peripheral portion of the shutter member, a cleaning device including the toner transport device, and an image forming apparatus. .

According to a first aspect of the present invention, there is provided a toner transport unit that transports toner in the transport path, a transport port provided in the transport path for carrying in or out the toner, and a shutter member that opens and closes the transport port. In the toner conveying device, a driving unit that can drive the shutter member to open and close the conveying port at an arbitrary timing is provided , and the shutter member is accommodated in the conveying path and the conveying port is opened. A cylindrical main body that is slidable in an axial direction between a position to be closed and a position to be closed, and an abutting portion that is exposed to the outside of the conveyance path, and the driving means biases the main body. A biasing means, a cam surface that abuts against the abutting portion, a cam member that slides the shutter member against the biasing force of the biasing means, and a drive source that drives the cam member, cam member, before While being rotatably driven about a rotation axis of the sliding direction of the shutter member by the drive source, the cam surface is a surface inclined with respect to the sliding direction of the shutter member.

  By driving the shutter member by the driving means, the toner in the conveyance path is loosened, and the toner can be prevented from staying in the periphery of the shutter member. In addition, since the shutter member can be driven at an arbitrary timing, the toner can be loosened by driving the shutter member before the toner is fixed in the conveyance path.

  According to a second aspect of the present invention, in the toner conveying device according to the first aspect, the shutter member is driven by the driving unit at least when the toner is conveyed by the toner conveying unit.

  By driving the shutter member during toner conveyance, in which toner tends to stay in the conveyance path, toner retention or fixation can be effectively prevented.

  A third aspect of the present invention is the toner conveying device according to the first or second aspect, wherein the shutter member is made of a conductive material and grounded.

  Since the shutter member is made of a conductive material and grounded, the shutter member can be prevented from being frictionally charged by driving. Thus, toner adhesion due to frictional charging of the shutter member can be prevented, and toner transportability can be improved.

  According to a fourth aspect of the present invention, in the toner conveying device according to any one of the first to third aspects, the shutter member is constituted by a low friction member or a low friction processed member.

  By configuring the shutter member with a low-friction member or a member subjected to low-friction processing, the adhesion between the shutter member and the toner can be reduced and the toner transportability can be improved.

According to a fifth aspect of the present invention, there is provided a cleaning apparatus comprising: a toner removing unit that removes toner remaining on a surface of an image carrier; and a toner conveying device that conveys the toner removed by the toner removing unit. And the toner conveying device according to any one of claims 1 to 4 .

Since the cleaning device includes the toner conveying device according to any one of claims 1 to 4 , the above-described effects of these toner conveying devices can be obtained.

A sixth aspect of the present invention is the cleaning apparatus according to the fifth aspect , wherein the image carrier is a transfer body that transfers a toner image onto paper.

  When the surface of the transfer body that transfers the toner image to the paper is cleaned, the paper dust adhering to the transfer body is also removed together with the toner. For this reason, paper powder is mixed in the removed toner. In this case, the toner is likely to aggregate, and the toner is likely to stay and adhere in the conveyance path. By providing the toner conveying device of the present invention in such a cleaning device in which toner stays and sticks easily, the effect of preventing the toner staying and sticking can be remarkably exhibited.

A seventh aspect of the invention is an image forming apparatus including the toner conveying device according to any one of the first to fourth aspects or the cleaning device according to the fifth or sixth aspect .

Since the image forming apparatus includes the toner conveying device according to any one of claims 1 to 4 or the cleaning device according to claim 5 or 6 , the toner conveying device or the cleaning device described above is used. An effect is obtained.

  According to the present invention, the toner in the conveyance path can be loosened by driving the shutter member at an arbitrary timing. For this reason, the toner can be prevented from staying or sticking in the conveyance path, and the toner conveyance performance can be maintained well.

1 is a schematic configuration diagram of an image forming apparatus according to an embodiment of the present invention. It is a schematic block diagram of the belt cleaning apparatus which concerns on this invention. FIG. 3 is a diagram of the belt cleaning device viewed from an intermediate transfer belt side. FIG. 3 is an enlarged cross-sectional view of a toner transfer tube. FIG. 3 is an enlarged cross-sectional view of a toner transfer tube. It is a perspective view showing the external appearance of a shutter member.

  FIG. 1 is a schematic configuration diagram of an image forming apparatus according to an embodiment of the present invention. The image forming apparatus shown in FIG. 1 includes four process units 1Y, 1C, 1M, and 1Bk. Each of the process units 1Y, 1C, 1M, and 1Bk is configured to be detachable from the image forming apparatus main body 100. The process units 1Y, 1C, 1M, and 1Bk have the same configuration except that they contain toners of different colors of yellow, cyan, magenta, and black corresponding to the color separation components of the color image.

  Specifically, each of the process units 1Y, 1C, 1M, and 1Bk includes a photosensitive member 2 as an electrostatic latent image carrier, a charging roller 3 as a charging unit that charges the surface of the photosensitive member 2, and a photosensitive member 2. A developing device 4 as a developing means for forming a toner image on the surface thereof, and a cleaning blade 5 as a toner removing means for removing the toner remaining on the surface of the photoreceptor 2.

  In FIG. 1, an exposure device 7 as an exposure unit is disposed above each process unit 1Y, 1C, 1M, 1Bk. The exposure device 7 is configured to irradiate the photoconductor 2 of each process unit 1Y, 1C, 1M, 1Bk with laser light. On the other hand, a transfer device 6 is disposed below the process units 1Y, 1C, 1M, and 1Bk. The transfer device 6 has an intermediate transfer belt 10 formed of an endless belt as a transfer body for transferring an image. The intermediate transfer belt 10 is stretched around a plurality of rollers 21 to 24, and one of the rollers 21 to 24 rotates as a driving roller, so that the intermediate transfer belt 10 rotates in the direction indicated by the arrow in the figure. It is configured to be able to run.

  Four primary transfer rollers 11 as primary transfer means are disposed at positions facing the four photoconductors 2. Each primary transfer roller 11 presses the inner peripheral surface of the intermediate transfer belt 10 at each position, and a primary transfer nip is formed at a location where the pressed portion of the intermediate transfer belt 10 and each photoconductor 2 are in contact with each other. ing. A secondary transfer roller 12 as a secondary transfer unit is disposed at a position facing one roller 24 that stretches the intermediate transfer belt 10. The secondary transfer roller 12 presses the outer peripheral surface of the intermediate transfer belt 10, and a secondary transfer nip is formed at a location where the secondary transfer roller 12 and the intermediate transfer belt 10 are in contact with each other.

  A belt cleaning device 9 as a cleaning device for cleaning the surface (outer peripheral surface) of the intermediate transfer belt 10 is disposed at a position facing the lower surface of the intermediate transfer belt 10.

  A plurality of paper feed cassettes 13 that contain recording paper P (recording medium) that is a sheet material are disposed below the image forming apparatus main body 100. Each paper feed cassette 13 is provided with a paper feed roller 14 that feeds the stored recording paper P. A paper discharge tray 20 for stocking the recording paper P discharged outside the apparatus is provided on the left outer surface of the image forming apparatus main body 100 in the drawing.

  In the image forming apparatus main body 100, a transport path R1 for transporting the recording paper P from the paper feed cassette 13 through the secondary transfer nip to the paper discharge tray 20 is disposed. In the transport path R1, a registration roller 15 is disposed upstream of the position of the secondary transfer roller 12 in the recording paper transport direction. Further, a conveyance belt 19, a fixing device 8, and a pair of paper discharge rollers 16 are sequentially arranged on the downstream side in the recording paper conveyance direction from the position of the secondary transfer roller 12. The conveyor belt 19 is held by a plurality of rollers so as to be rotatable (or capable of traveling around). The fixing device 8 includes a heating roller 17 having a heating source therein, and a pressure roller 18 that presses the heating roller 17. The heating roller 17 and the pressure roller 18 are in pressure contact with each other, and a fixing nip is formed at the pressure contact portion.

  In addition, a reversing path R <b> 2 is provided in the image forming apparatus main body 100 for supplying the recording paper P with its front and back reversed when performing duplex printing. The reversing path R <b> 2 branches from the transport path R <b> 1 between the fixing device 8 and the paper discharge roller 16, and joins the transport path R <b> 1 on the upstream side of the registration roller 15. The reverse path R2 is provided with a switchback roller 26 that rotates in the forward and reverse directions.

The basic operation of the image forming apparatus will be described below with reference to FIG.
The photoreceptors 2 of the process units 1Y, 1C, 1M, and 1Bk are rotationally driven counterclockwise in the figure, and the surface of each photoreceptor 2 is uniformly charged to a predetermined polarity by the charging roller 3. Based on image information of a document read by a reading device (not shown), the surface of each photoconductor 2 charged from the exposure device 7 is irradiated with laser light, and an electrostatic latent image is formed on the surface of each photoconductor 2. Is done. At this time, the image information to be exposed on each photoconductor 2 is monochromatic image information obtained by separating a desired full-color image into color information of yellow, cyan, magenta, and black. The electrostatic latent image formed on the photoreceptor 2 in this way is supplied with toner by each developing device 4, whereby the electrostatic latent image is visualized as a toner image.

  One of the rollers that stretches the intermediate transfer belt 10 is driven to rotate, and the intermediate transfer belt 10 runs around in the direction of the arrow in the figure. Also, a primary transfer nip between each primary transfer roller 11 and each photoreceptor 2 is applied to each primary transfer roller 11 by applying a constant voltage or a voltage controlled by a constant current opposite to the charging polarity of the toner. A transfer electric field is formed. Then, the toner images of the respective colors formed on the respective photoconductors 2 are sequentially superimposed and transferred onto the intermediate transfer belt 10 by the transfer electric field formed in the primary transfer nip. Thus, the intermediate transfer belt 10 carries a full-color toner image on its surface. Further, the toner that could not be transferred onto the intermediate transfer belt 10 remains on the surface of each photoreceptor 2 after the transfer. The toner remaining on the photoreceptor 2 is removed by the cleaning blade 5.

  Further, the recording paper P is carried out of the paper feed cassette 13 by the rotation of the paper feed roller 14. The discharged recording paper P is timed by the registration roller 15 and is sent to the secondary transfer nip between the secondary transfer roller 12 and the intermediate transfer belt 10. At this time, a transfer voltage having a polarity opposite to the toner charging polarity of the toner image on the intermediate transfer belt 10 is applied to the secondary transfer roller 12, and a transfer electric field is formed in the secondary transfer nip. Then, the toner image on the intermediate transfer belt 10 is collectively transferred onto the recording paper by the transfer electric field formed in the secondary transfer nip. Further, the toner remaining on the surface of the intermediate transfer belt 10 after the transfer is removed by the belt cleaning device 9.

  The recording paper P to which the toner image has been transferred is conveyed to the fixing device 8 by the rotating conveyance belt 19. The recording paper P sent to the fixing device 8 is sandwiched between the heating roller 17 and the pressure roller 18 and heated and pressurized, and the toner image is fixed on the recording paper P. Thereafter, the recording paper P is discharged to the paper discharge tray 20 by the pair of discharge rollers 16.

  When performing double-sided printing, the recording paper P having an image fixed on one side (front side) is conveyed to the reversing path R2 without being discharged to the paper discharge tray 20 by a branching claw (not shown). The recording paper P conveyed to the reversing path R2 is conveyed in the reverse direction by the reverse rotation by the switchback roller 26, and is sent again to the conveying path R1. This is generally called a switchback operation, and the front and back of the recording paper P are reversed by this operation.

  The reversed recording paper P is conveyed to the secondary transfer nip, and the image is transferred to the back surface of the recording paper P in the secondary transfer nip in the same manner as when the image is transferred to one side. Then, after the image is fixed on the back surface of the recording paper P by the fixing device 8, the recording paper P is discharged to the paper discharge tray 20.

  The above description is an image forming operation when a full-color image is formed on a recording sheet. A single-color image is formed using any one of the four process units 1Y, 1C, 1M, and 1Bk. Two or three process units can be used to form a two or three color image.

  Hereinafter, based on FIGS. 2-6, the structure of the said belt cleaning apparatus 9 which is the characterizing part of this invention is demonstrated. 2-6, the same code | symbol shows the same member or part.

FIG. 2 is a schematic configuration diagram of the belt cleaning device.
As shown in FIG. 2, the belt cleaning device 9 has a blade 30 made of rubber such as polyurethane. The blade 30 is in contact with the counter roller 33 via the intermediate transfer belt 10. As the intermediate transfer belt 10 moves in the direction of the arrow in the figure, the residual toner on the intermediate transfer belt 10 is scraped off and removed by the blade 30. As described above, by using the blade 30 as the toner removing means, it is possible to secure an inexpensive and reliable cleaning property. However, in such a cleaning method using a blade, if paper dust is caught between the blade 30 and the intermediate transfer belt 10, there is a possibility that a cleaning failure may occur. In particular, in the present embodiment, the recording paper comes into contact with the intermediate transfer belt 10, and it is inevitable that paper dust adheres to the intermediate transfer belt 10.

  Therefore, in this embodiment, in order to prevent paper dust from being caught between the blade 30 and the intermediate transfer belt 10, the paper dust removing member 31 is disposed on the upstream side (downward in the drawing) of the blade 30 in the traveling direction. doing. Here, a brush roller is used as the paper dust removing member 31. The brush roller is in contact with the counter roller 33 via the intermediate transfer belt 10. In this way, the paper dust adhering to the intermediate transfer belt 10 is removed by bringing the brush roller into contact with the intermediate transfer belt 10. The brush roller may be configured to rotate with the traveling intermediate transfer belt 10, but it is preferable that the brush roller is rotated by applying a driving force to the paper roller in terms of improving paper dust removal. Here, PET resin is used as the material of the brush roller hair. In addition, since the toner can be removed simultaneously with the paper dust removal by the brush roller, the effect of reducing the load on the blade 30 and extending the life of the blade 30 can be expected.

  The belt cleaning device 9 has a conveying screw 32 as toner conveying means for conveying the toner removed by the blade 30. The toner conveyed by the conveying screw 32 is accommodated in a waste toner container (not shown). The conveying screw 32, the blade 30, the brush roller as the paper dust removing member 31, etc. are held in the casing 34.

FIG. 3 is a view of the belt cleaning device viewed from the intermediate transfer belt side.
In FIG. 3, a cylindrical toner transfer pipe 35 having a conveyance path for conveying toner is protruded at the lower part of the right side surface of the casing 34, and the tip of the toner discharge portion 35 (shown in the figure). A discharge port 36 for discharging the toner in the casing 34 is formed at the right end). The discharge port 3 is connected to a waste toner container by a waste toner transfer hose (not shown).

4 and 5 are enlarged sectional views of the toner transfer tube.
As shown in FIG. 4 or FIG. 5, one end portion of the conveying screw 32 is accommodated in the conveying path 35 b of the toner transfer pipe 35. As the conveying screw 32 rotates, the toner in the casing is conveyed to the discharge port 35a. A shutter member 36 that opens and closes the discharge port 35a is accommodated in the transport path 35b.

  As shown in FIG. 6, the shutter member 36 has a cylindrical main body 36 a and a projecting piece-shaped contact 36 b provided at the end of the main body 36 a. As shown in FIG. 4 or 5, the main body 36 a of the shutter member 36 is accommodated in the conveyance path 35 b, but the contact portion 36 b is a through hole formed in the right end surface of the toner transfer tube 35 in the drawing. It is exposed to the outside from 35c. Further, the shutter member 36 is configured to be slidable in the transport path 35b, and opens and closes the discharge port 35a as the shutter member 36 slides.

  FIG. 4 shows a state in which the shutter member 36 opens the discharge port 35a. In this case, the toner conveyed by the conveying screw 32 passes through the main body 36a of the shutter member 36 and is discharged from the discharge port 35a. On the other hand, FIG. 5 shows a state in which the shutter member 36 closes the discharge port 35a. In this case, the discharge port 35 a is closed by the main body 36 a of the shutter member 36.

  In order to prevent frictional charging due to the sliding movement of the shutter member 36, it is preferable that the shutter member 36 is made of a conductive material and grounded (ground connection). Accordingly, toner adhesion due to frictional charging of the shutter member 36 can be prevented, and toner transportability can be improved.

  Further, in order to reduce the adhesion force between the shutter member 36 and the toner and improve the toner transportability, it is desirable that the shutter member 36 is composed of a low friction member or a low friction processed member.

  The belt cleaning device of the present invention includes a driving unit that slides the shutter member 36. As shown in FIG. 4 or FIG. 5, this driving means includes a coil spring 37 as an urging means for urging the shutter member 36, a cam member 38 for applying a driving force to the shutter member 36, and the cam member 38. And a drive source (not shown) to be driven.

  The coil spring 37 is compressed and accommodated in the conveyance path 35b, and the right end (free end) of the coil spring 37 in the drawing contacts the main body 36a of the shutter member 36 so that the shutter member 36 moves to the right in the drawing. Energized. Further, the left end portion of the coil spring 37 in the drawing is in contact with an abutting portion (not shown) provided in the conveyance path 35b or in the casing.

  The cam member 38 is disposed outside the conveyance path 35b and is configured to be rotatable by the drive source. The cam member 38 has a cam surface 38a that is inclined with respect to the direction in which the shutter member 36 slides (the left-right direction in the figure), and the contact portion 36b of the shutter member 36 contacts the cam surface 38a. Yes. When the cam member 38 is rotated, the contact portion 36b follows the cam surface 38a, so that the shutter member 36 can be slid against the urging force of the coil spring 37.

  In the present embodiment, in order to suppress a reduction in driveability of the conveyance screw 32 and vibration and noise due to the conveyance screw 32 coming into contact with the inner surface of the toner transfer pipe 35 and the inner surface of the shutter member 36, The outer diameter is smaller than the inner diameter of the toner transfer tube 35 or the inner diameter of the shutter member 36. Therefore, gaps are generated between the conveying screw 32 and the toner transfer pipe 35 and between the conveying screw 32 and the shutter member 36. In this gap, since the conveying force of the conveying screw 32 with respect to the toner is hardly exerted, the toner stays and the toner tends to adhere to the inner surfaces of the toner transfer pipe 35 and the shutter member 36.

  Therefore, in the present invention, the sliding operation of the shutter member 36 as described above is performed while the toner is being transported by the transport screw 32, so that the toner in the transport path 35b is loosened and the toner stays in the periphery of the shutter member 36. Alternatively, it is prevented from sticking. As a result, it is possible to prevent the occurrence of problems such as toner conveyance failure due to toner staying or adhering in the conveyance path 35b, and clogging of the conveyance path and locking of the conveyance screw due to the growth of the adhered toner. In addition, it is possible to maintain good toner transportability.

  Further, the sliding movement of the shutter member can be performed at any timing other than during toner conveyance. As described above, in the present invention, since the sliding movement of the shutter member can be performed at an arbitrary timing, the toner can be loosened by driving the shutter member before the toner is fixed in the conveyance path.

  In this embodiment, the configuration of the present invention is applied to a cleaning device that cleans the intermediate transfer belt. In this case, when removing the toner from the intermediate transfer belt, the paper dust and lubricant adhering to the intermediate transfer belt are also removed, so that the paper dust and lubricant are mixed in the removed toner. . In particular, when paper dust and a lubricant are mixed in the toner as described above, the toner is likely to aggregate, and the toner is likely to stay and adhere in the conveyance path. However, by applying the configuration of the present invention, In addition, it is possible to remarkably exhibit the effect of preventing toner retention and sticking.

  In addition, when the image forming apparatus to which the configuration of the present invention is applied is a color image forming apparatus, the amount of waste toner passing through the conveyance path is larger than that of the monochrome image forming apparatus, so that toner stays and adheres. Cheap. Also in this case, by applying the configuration of the present invention, it is possible to remarkably exhibit the effect of preventing toner retention and sticking.

The embodiment of the present invention has been described above, but the present invention is not limited to the above-described embodiment, and it is needless to say that various modifications can be made without departing from the gist of the present invention. Further , the shutter member can be driven separately from the opening / closing operation.

  In the above-described embodiment, the shutter member is provided at the discharge port for carrying out the toner. However, the configuration of the present invention can be applied even when the shutter member is provided at the supply port for carrying in the toner. is there. In other words, the shutter member only needs to be provided at the conveyance port for carrying in or carrying out the toner.

  In the above-described embodiment, the case where the configuration of the present invention is applied to a cleaning device that cleans the intermediate transfer belt as the image carrier is taken as an example. However, the cleaning that cleans the photoreceptor as the image carrier is described. The configuration of the present invention can also be applied to an apparatus. The configuration of the present invention can also be applied to a toner conveying device that does not have a cleaning unit.

  The image forming apparatus according to the present invention is not limited to a color image forming apparatus, but may be a monochrome image forming apparatus, a copier, a printer, a facsimile, or a complex machine thereof.

9 Belt cleaning device 30 Blade (toner removing means)
32 Conveying screw (toner conveying means)
35a Discharge port 35b Carriage path 36 Shutter member 36a Main body part 35b Abutting part 37 Coil spring (biasing means)
38 Cam member

Japanese Patent Laid-Open No. 2005-49900

Claims (7)

In a toner conveying apparatus comprising: a toner conveying unit that conveys toner in a conveying path; a conveying port provided in the conveying path for carrying in or out the toner; and a shutter member that opens and closes the conveying port.
Provided is a driving means capable of driving the shutter member to open and close the transport port at an arbitrary timing ;
The shutter member is accommodated in the conveyance path, and has a cylindrical main body that is slidable in an axial direction between a position where the conveyance port is opened and a position where the conveyance port is closed , and a contact exposed outside the conveyance path. Part
The drive means includes an urging means for urging the main body part, a cam member having a cam surface abutting on the abutting part and sliding the shutter member against the urging force of the urging means, A drive source for driving the cam member;
Said cam member is rotatably driven about a rotation axis of the sliding direction of the shutter member by said drive source, said cam surface is a surface inclined with respect to the sliding direction of the shutter member A toner conveying device.   The toner conveying device according to claim 1, wherein the shutter member is driven by the driving unit at least during toner conveyance by the toner conveying unit.   The toner conveying device according to claim 1, wherein the shutter member is made of a conductive material and is grounded. 4. The toner conveying device according to claim 1, wherein the shutter member is formed of a low friction member or a low friction processed member. 5. In a cleaning apparatus comprising: a toner removing unit that removes toner remaining on the surface of an image carrier; and a toner conveying device that conveys the toner removed by the toner removing unit.
A cleaning device comprising the toner transport device according to claim 1 as the toner transport device . The cleaning apparatus according to claim 5, wherein the image carrier is a transfer body that transfers a toner image onto paper . An image forming apparatus comprising the toner conveying device according to claim 1 or the cleaning device according to claim 5 or 6 .

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