JP2005173350A - Image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To maintain stable cleaning performance without increasing toner consumption in an image forming apparatus, and to improve economy and productivity.
A cleaning blade 21 is provided in a waste toner collection box 20 to be in contact with a transfer conveyance belt 17, and an opening 20a is formed on the upstream side thereof. Then, waste toner transport pipes 10 to 13 are provided between the respective photoreceptor cleaning units 6 to 9 and the waste toner collection box 20 of each image forming unit to clean the residual toner removed from the photoreceptor drums 2a to 5a. The toner is discharged to the vicinity of the transfer conveyance belt 17 on the upstream side of the blade 21. Thereby, the cleaning blade 21 is prevented from being twisted.
[Selection] Figure 1

Description

  The present invention relates to an image forming apparatus. More particularly, the present invention relates to an electrophotographic image forming apparatus that collects toner adhering to an image carrier or a belt transfer member in a waste toner collecting container. Further, the present invention relates to an apparatus suitable for, for example, a tandem type color image forming apparatus that forms toner images on a plurality of image carriers with a plurality of color toners, and finally transfers them to a recording material to form a color image. It is.

In recent years, a tandem type image forming apparatus in which a plurality of image forming units are arranged along a circulating belt so that a full color image can be printed at high speed by an electrophotographic method is becoming widespread.
Conventionally, in such an image forming apparatus, a cleaning unit is provided in order to repeatedly use a photoreceptor of an image forming unit and a transfer belt for transferring an image. In order to efficiently use the space occupied by these, particularly the space of each waste toner collection container, the waste toner collected by the respective cleaning means is conveyed outside the cleaning means by the waste toner transfer means. Some of them are collected in a common waste toner collecting container. As a cleaning means, a counter blade cleaning method that is simple but has high cleaning performance is used.
For example, in Patent Document 1, four image forming units and a belt cleaning unit are disposed on an intermediate transfer belt, and a cleaning blade is brought into contact with a photosensitive drum and a counter against the intermediate transfer belt, respectively. An image forming apparatus is described in which toner scraped off is transported by a transport unit as waste toner and can be collected in a waste toner box.
JP 2001-324905 A (page 4-5, FIGS. 1 and 4)

However, the conventional image forming apparatus as described above has the following problems.
In the technique described in Patent Document 1, since the collected waste toner is conveyed from the image forming unit and the belt cleaning unit, the waste toner is not stored so much in each unit. Further, there is a problem that the friction with the intermediate transfer belt is increased and the cleaning blade is easily swollen. Once the cleaning blade is rolled, normal image formation cannot be performed and replacement and repair are required.
In particular, since the intermediate belt is friction driven, it can not be driven stably when the frictional force of the contact portion of the cleaning blade fluctuates greatly compared to the gear driven photosensitive drum, and the cleaning blade is more likely to be swollen. There is a problem of affecting.
In addition, when small-sized images are continuously formed, untransferred toner remains in the image area to some extent, but cleaning is repeated outside the image area and the toner in the contact portion is depleted, so that the cleaning blade There is a problem that an unbalance of the frictional force is generated, and the cleaning blade is likely to bend.
In addition, in an apparatus using a transfer conveyance belt that adsorbs and conveys transfer paper and transfers a toner image onto the transfer paper without using an intermediate transfer belt, a belt cleaning unit is provided on the transfer conveyance belt. In such an apparatus, since the toner image is transferred to the transfer paper, only a small amount of toner, paper dust, or the like that has fallen from the image forming unit adheres to the transfer conveyance belt. As a result, there is a problem that the cleaning blade is more likely to bend.
Therefore, every time a predetermined number of sheets are printed, an appropriate image pattern is drawn in the non-image forming area, and the friction force reducing toner is brought into contact with each cleaning blade, the photosensitive drum, the intermediate transfer belt, and the transfer conveyance belt. In some cases, printing is interrupted to provide a cleaning cycle. In this case, although the curl of the cleaning blade is improved, the printing is interrupted, so that the productivity of image formation is lowered, and there is a problem that it becomes uneconomical by consuming toner that does not form an image.

  The present invention has been made in view of the above-described problems, and provides an image forming apparatus that can maintain stable cleaning performance without increasing toner consumption and is excellent in economy and productivity. For the purpose.

In order to solve the above-described problems, the invention according to claim 1 is an image forming apparatus that finally transfers a toner image formed on an image carrier to a recording material to form an image, and An image carrier cleaning unit that removes toner remaining on the image carrier after the toner image is transferred from the image carrier, and is provided in the vicinity of the image carrier, and is formed on the image carrier. A transfer means for sucking and transferring the toner image; and a belt transfer body comprising an endless belt whose surface is moved at the same linear speed as the linear speed of the image carrier between the transfer means and the image carrier. A belt transfer member cleaning unit that contacts the surface of the belt transfer member to remove deposits on the surface, and is disposed in the vicinity of the belt transfer member cleaning unit and the belt transfer member. Removed A waste toner collection container that can store the adhering matter and the toner removed by the image carrier cleaning means, and a toner that is removed by the image carrier cleaning means is conveyed into the waste toner collection container. Waste toner transfer means for discharging, and the toner discharged from the waste toner transfer means is discharged to the vicinity of the belt transfer body upstream of the belt transfer body cleaning means.
According to the present invention, the toner remaining on the image carrier removed by the image carrier cleaning unit is conveyed by the waste toner transfer unit, and is disposed in the vicinity of the belt transfer unit cleaning unit and in the vicinity of the belt transfer unit. Discharge to waste toner collection container. At that time, since the toner is discharged to the vicinity of the belt transfer body upstream of the belt transfer body cleaning means, the toner is supplied to the contact portion between the belt transfer body and the belt cleaning means, and the toner is It is possible to prevent the frictional force from increasing due to depletion.

According to a second aspect of the present invention, in the image forming apparatus according to the first aspect, the belt transfer body cleaning unit includes at least a blade-like member that contacts the belt transfer body.
According to the present invention, since the belt transfer member cleaning means is constituted by the blade-like member in contact with the belt transfer member, the cleaning performance is high while being inexpensive. In order to improve the cleaning performance of the blade-shaped member, it is preferable to make a counter contact with the belt transfer member.

According to a third aspect of the present invention, in the image forming apparatus according to the second aspect, the blade member has a tensile elastic modulus of 20 MPa or less.
According to the present invention, since the tensile elastic modulus is 20 Mpa or less, the contact pressure on the belt transfer body can be reduced, and the driving load on the belt transfer body can be reduced. Further, since the belt transfer body is hardly damaged, the life of the belt transfer body can be extended.

According to a fourth aspect of the present invention, in the image forming apparatus according to the second or third aspect, the belt transfer body cleaning unit includes at least one of a brush-shaped member, a roll-shaped member, and a pad-shaped member. .
According to this invention, in addition to the blade-like member, by providing at least one of the brush-like, roll-like and pad-like members, the cleaning performance can be shared among them, so the contact pressure of each member Thus, the belt transfer body and its driving load can be reduced.
Further, if at least one of the brush-like, roll-like and pad-like members is arranged on the upstream side of the blade-like member, the toner discharged from the waste toner transfer means and the toner adhering to the belt transfer member are averaged by them. Further, the frictional force of the contact portion between the blade-like member and the belt transfer member can be further stabilized because the contact portion can be held to some extent.

According to a fifth aspect of the present invention, in the image forming apparatus according to the fourth aspect, at least one of the brush-shaped, roll-shaped and pad-shaped members provided in the belt transfer body cleaning means is a belt transfer body. A bias voltage for sucking toner adhering to the toner can be applied.
According to the present invention, since the bias voltage for sucking the toner adhering to the belt transfer body can be applied to at least one of the brush-shaped, roll-shaped and pad-shaped members that are in contact with the belt transfer body, the cleaning performance is improved. Can be improved.

According to a sixth aspect of the present invention, in the image forming apparatus according to any one of the first to fifth aspects, the waste toner collection container has an opening facing the belt transfer body upstream of the belt transfer body cleaning unit. It is set as the structure which has.
According to the present invention, the toner discharged into the waste toner collecting container can adhere to the belt transfer member through the opening facing the belt transfer member. Accordingly, the toner can be distributed in the range of the opening on the upstream side of the belt transfer member cleaning unit. Therefore, an appropriate toner distribution can be formed on the belt transfer body depending on the size and shape of the opening.

According to a seventh aspect of the present invention, in the image forming apparatus according to any one of the first to sixth aspects, a plurality of the image carrier, the image carrier cleaning unit, the transfer unit, and the waste toner transfer unit are provided. A toner image is formed with toners of different colors, and the toner images are finally transferred in color on a recording material so that a color image can be formed.
According to the present invention, since the toner removed by the plurality of image carrier cleaning means is collected by one waste toner collecting container, a compact apparatus can be obtained.

  According to the image forming apparatus of the present invention, since the toner removed by the image carrier cleaning unit is discharged in the vicinity of the belt transfer member upstream of the belt transfer member cleaning unit, the belt transfer of the belt transfer member cleaning unit is performed. Since the increase in frictional force at the contact portion between the belt transfer body and the belt cleaning means can be suppressed without supplying and consuming toner to the contact portion with respect to the body, it has stable cleaning performance, economy and production It is possible to obtain an image forming apparatus having excellent properties.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
An image forming apparatus according to an embodiment of the present invention will be described.
FIG. 1 is a schematic explanatory view of a front cross-sectional view for explaining a schematic configuration of a main part of an image forming apparatus according to an embodiment of the present invention.

A color printer 1 (image forming apparatus) according to an embodiment of the present invention whose main part is shown in FIG. 1 separates an image to be printed into yellow, magenta, cyan, and black. This is a tandem color image forming apparatus that forms an image by visualizing a color separation image as a toner image and finally transferring the color separation image onto a transfer paper 25 (recording material).
The color printer 1 naturally includes well-known means included in an electrophotographic color image forming apparatus. For example, a charging unit that applies an initial potential to the image carrier, an exposure unit that forms a latent image on the image carrier, a developing unit that forms a toner image by attaching toner according to the latent image potential, and transfer paper are supplied. Transfer paper transporting means for transporting, a fixing means for fixing a toner image on the transfer paper, an image signal forming means for supplying an image signal to the exposure means, a process control means for controlling potential conditions such as charging, development, transfer, etc. Drive control means for controlling the drive and drive sequence of the movable part. These can adopt a configuration in which known techniques are appropriately combined. Therefore, illustration is omitted, and a brief description will be given as necessary.
Hereinafter, the main part of the color printer 1 will be mainly described.

The schematic configuration of the main part of the color printer 1 includes image forming units 2, 3, 4, 5, 4, four transfer rollers 14 (transfer means), a transfer conveyance belt 17 (belt transfer body), and a waste toner collection box 20 (waste). Toner collecting container) and cleaning blade 21 (belt transfer member cleaning means).
In the following description, in order to simplify the description of symbols, when serial numbers are listed, for example, “2, 3, 4, 5” is simply “2-5”, “2a, 3a, 4a, 5a”. May be simply abbreviated as “2a-5a”.

The image forming unit 2 includes a photosensitive drum 2a (image carrier) having a photoconductive layer formed on the surface of a cylindrical member extending in the depth direction of the illustrated paper. The photosensitive drum 2a has an effective image forming area that is equal to or larger than the width of the transfer paper 25, and can be rotated in the direction of the rotation arrow in the drawing by the drive control means.
On the outer periphery of the photosensitive drum 2a, the photosensitive member cleaning unit 6 extended to the range of the effective image forming area, the charging means (not shown), the light beam incident portion of the exposure means, and the developing means are indicated by the rotation arrows. Arranged in this order along the direction. The transfer position for transferring the toner image is provided upstream of the photoconductor cleaning unit 6 and downstream of the developing means.

The schematic structure of the photoconductor cleaning unit 6 includes a cleaning blade 6a (image carrier cleaning means) and a housing 6b.
The cleaning blade 6a is an elastic plate member made of, for example, synthetic rubber and formed in a substantially rectangular shape. Then, the front end corner portion in the longitudinal direction uniformly contacts the surface of the photosensitive drum 2a along the axial direction of the photosensitive drum 2a in a counter posture with respect to the rotation direction. The toner remaining on the photosensitive drum 2 is prevented from passing through and can be removed from the photosensitive drum 2a.

  The housing 6b is a member that positions and holds the cleaning blade 6a with respect to the photosensitive drum 2a and forms a space for temporarily storing the toner removed by the cleaning blade 6a.

The housing 6b is provided with a waste toner transport pipe 10 (waste toner transfer means) for discharging and transporting the toner stored inside the housing 6b to the outside. The discharge port 10a of the waste toner conveyance tube 10 is provided on the upstream side of the cleaning blade 21 inside the waste toner collection box 20 described later.
As the configuration of the waste toner conveying tube 10, for example, a configuration in which an auger mechanism capable of rotating around a pipe extending direction is provided in a bent pipe. As the auger mechanism, for example, a bendable screw-like member, an ellipse plate or the like attached with an inclination to the rotation axis can be suitably employed.
Each of the planes extends in the illustrated depth direction in the housing 6b and the waste toner collection box 20, and is connected so that one end of each is inclined from the housing 6b toward the waste toner collection box 20. A substantially U-shaped conveyance path is formed. Thereby, the toner stored in the housing 6b can be smoothly transferred into the waste toner collection box 20 by the auger mechanism and the inclination of the transport path.
The discharge port 10a may be provided at the tip of the waste toner conveyance tube 10, or may be provided at a plurality of locations in the middle of the waste toner conveyance tube 10 so that the toner conveyed to a plurality of locations in the waste toner collection box 20 falls. . In either case, it is preferable to provide the opening of the discharge port 10 a so as to face the transfer conveyance belt 17 so that the discharged toner is easily attached to the transfer conveyance belt 17.

Each of the image forming units 3, 4, and 5 has the same configuration as that of the image forming unit 2. For example, photosensitive drums (image carriers) 3a, 4a, and 5a are provided corresponding to the photosensitive drum 2a, and photosensitive member cleaning units 7, 8, and 9 are provided corresponding to the photosensitive member cleaning unit 6, respectively. The photoconductor cleaning units 7, 8, and 9 include cleaning blades (image carrier cleaning means) 7a, 8a, and 9a and housings 7b, 8b, and 9b corresponding to the cleaning blade 6a and the housing 6b, respectively. Further, similarly to the image forming unit 2, other units (not shown) are provided.
The housings 7 b, 8 b, and 9 b are provided with waste toner transport pipes 11, 12, and 13 that correspond to the waste toner transport pipe 10 and that have different transport paths depending on the transfer distance. In this case, the positions of the discharge ports 10a to 13a in the image width direction (the depth direction in the drawing) may be appropriate, but in order to equalize the frictional force reduction effect of the discharged toner in the width direction, for example, It is preferable that they are arranged at substantially equal intervals in the conveyance width direction without overlapping in the belt conveyance direction.

However, the color of the toner supplied to each developing unit of the image forming units 2 to 5 is different. For example, yellow, magenta, cyan, and black toners are supplied, and light beams are incident from the exposure units by image signals that have been color-separated by the respective colors, and corresponding colors on the photosensitive drums 2a to 5a. A toner image can be formed.
The image forming units 2 to 5 are arranged such that the rotation axes of the photosensitive drums 2a to 5a are parallel with a predetermined drum interval, and the transfer positions are aligned on the same plane.

  Each of the transfer rollers 14 is arranged so as to be pressed lightly via a transfer conveyance belt 17 described later, one by one at a position facing each transfer position of the photosensitive drums 2a to 5a. It is the roller member provided in this way.

The transfer conveyance belt 17 is an endless belt including at least the transfer rollers 14 on the inner peripheral side and having a width wider than the effective image area. As the material of the transfer / conveying belt 17, an endless belt processed by forming a flexible synthetic resin into a sheet shape so that the transfer paper 25 can be electrostatically attracted to the transfer roller 14 by an electric potential can be used.
The driving roller 18 and the driven rollers 19a, 19b, and 19c are arranged in parallel to each other on the inner peripheral side so that they can be rotationally driven in one direction with an appropriate tension applied.

The drive roller 18 is a roller member that is provided on the downstream side of the image forming unit 5 and can be driven to rotate in the direction of the rotation arrow by a motor (not shown). The transfer / conveying belt 17 can be rotated at a linear speed synchronized with the linear speed of the photosensitive drums 2a to 5a.
The driven roller 19 a is an idle roller that is provided on the upstream side of the image forming unit 2 and whose rotation center is fixed at a position for forming the entrance of the transfer paper 25.
The driven roller 19b is an idle roller having a rotational center fixed on the upstream side in the rotational direction of the driven roller 19a. The roller surface is smooth and has a relatively high hardness.
The driven roller 19c is a tension roller that is pressed radially outward with respect to the transfer conveyance belt 17 by a biasing means (not shown) in order to apply tension to the transfer conveyance belt 17 bent by the driving roller 18.
As a result, as shown in FIG. 1, the cross-sectional shape of the transfer / conveying belt 17 is such that the surface stretched by the drive roller 18 and the driven roller 19a is the long side, and the surface stretched by the driven rollers 19b and 19c is the short side. It is stretched in a substantially trapezoidal shape.

The waste toner collection box 20 is disposed in the vicinity of the driven roller 19b on the outer peripheral side of the surface stretched by the driven rollers 19b and 19c, and has substantially the same cross section as illustrated in the width direction of the transfer conveyance belt 17, and the waste toner is disposed inside thereof. Is a box-shaped member in which a waste toner recovery space 20b for storing the toner is formed.
An opening 20 a for allowing a part of the conveyed toner to adhere to the transfer conveyance belt 17 is provided at a position facing the transfer conveyance belt 17 and at least in the vicinity of the discharge ports 10 a to 13 a. .

The cleaning blade 21 is an elastic plate member made of, for example, synthetic rubber and formed in a substantially rectangular shape. Then, it is fixed on an appropriate support member in the waste toner collecting box 20 and is placed on the surface of the wrapping angle range of the transfer conveyance belt 17 wound around the driven roller 19b in a counter posture with respect to the rotation direction. The tip end corner of the direction is abutted uniformly along the axial direction of the driven roller 19b.
In addition, it is possible to prevent the adhering matter such as toner and paper dust adhering to the transfer / conveying belt 17 from passing through and to remove it from the surface of the transfer / conveying belt 17.
The cleaning blade 21 has a shape and a material having a rigidity that does not buckle in a counter posture due to a frictional force received from the transfer conveyance belt 17. In the present embodiment, for example, a material having a tensile modulus not exceeding 20 MPa can be suitably used.

Next, the operation of the color printer 1 of the present embodiment will be described focusing on the operation of the main part.
When a print signal is input from the outside, an image signal that has been color-separated for each color is input to the exposure unit, and a latent image is formed and developed by the image forming units 2 to 5 by a light beam modulated accordingly. Is called. On the other hand, in synchronization with this, the transfer paper 25 is transported by the transfer paper transport means and is supplied onto the transfer transport belt 17 on the driven roller 19a side. Then, it is electrostatically adsorbed onto the transfer conveyance belt 17 and conveyed in the direction of the arrow shown in the figure (upper side). When the toner enters the contact portion between the image forming unit 2 and the transfer conveyance belt 17, the toner image on the photosensitive drum 2 a is electrostatically attracted onto the transfer paper 25 by the transfer roller 14 and sequentially transferred to a predetermined linear velocity. It is conveyed by.
Then, the toner images of the image forming units 3, 4, 5 are sequentially transferred by the transfer roller 14, and the four color toner images are sequentially superimposed on the transfer paper 25. Then, the transfer paper 25 is separated on the transfer conveyance belt 17 on the drive roller 18 side and conveyed to a fixing unit (not shown), and the toner image is fixed on the transfer paper 25.

On the other hand, toner that cannot be transferred by the transfer roller 14 remains as residual toner on each of the photosensitive drums 2a to 5a. In some cases, a part of the toners of other colors that contact at the transfer position are attracted to the surface of the photosensitive drum and become residual toner. When the photosensitive member cleaning units 6-9 are reached, the residual toner is removed and temporarily stored in the casings 6b-9b.
The temporarily stored residual toner is successively conveyed to the waste toner collection box 20 by the auger mechanism of the waste toner conveyance pipes 10 to 13. Then, the toner is discharged to the vicinity of the transfer conveyance belt 17 on the upstream side of the cleaning blade 21 through the discharge ports 10a to 13a.
Therefore, the toner discharged into the waste toner collection space 20b is scattered, and a part of the toner adheres to the transfer conveyance belt 17 through the opening 20a, and the other drops into the waste toner collection box 20.
On the other hand, if the toner falls from the image forming units 2 to 5 or the paper dust of the transfer paper 25 is generated on the outer side in the width direction of the transfer paper 25 or a non-image area between the transfer paper 25, static electricity is generated. They adhere to the surface of the transfer transfer belt 17 which is tinged, and are transferred on the transfer transfer belt 17.

Accordingly, the transfer / conveying belt 17 that has passed through the opening 20a is in a state in which the toner discharged from at least the discharge ports 10a to 13a is attached. Then, it is cleaned by the cleaning blade 21 and collected in the waste toner collection box 20 together with other adhering substances. In this way, the deposits on the surface of the transfer conveyance belt 17 are removed, so that a clean surface can be obtained on the downstream side and can be reused.
As described above, since the toner is always attached to the contact portion of the cleaning blade 21 with respect to the transfer conveyance belt 17, the toner is lubricated thereby, and the frictional force does not increase as in the case of contact with a clean surface. A stable low frictional force state can be maintained.
As a result, even if the rigidity of the cleaning blade 21 is relatively small, for example, the tensile modulus of elasticity is 20 MPa or less, it is possible to reliably prevent the dripping. Therefore, the cleaning blade 21 can be configured with an inexpensive member.
Further, since the rigidity of the cleaning blade 21 can be made relatively small, the contact pressure against the transfer / conveying belt 17 can be reduced, driving of the transfer / conveying belt 17 is reduced, and there is an advantage that smooth driving can be performed. . Furthermore, since scratches and wear on the surface of the transfer conveyance belt 17 can be reduced, there is an advantage that the life of the transfer conveyance belt 17 can be improved.

As described above, according to the present embodiment, the image forming units 2 to 5 do not need to have a dedicated toner collection container, and can be used as the waste toner collection box 20, so that a compact configuration can be achieved.
Further, when the transfer / conveying belt 17 is cleaned, the contact portion of the cleaning blade 21 is lubricated by the toner discharged from the discharge ports 10a to 13a and the frictional force is stabilized. Therefore, the cleaning blade 21 and the transfer / conveying belt 17 are stabilized. Therefore, it is possible to obtain a highly reliable image forming apparatus.
Further, unlike the conventional apparatus, it is not necessary to provide a cleaning cycle for forcibly supplying toner to the non-image area, so that the productivity of image formation may be inferior, and the toner consumption may be increased, which may be uneconomic. Absent. As a result, an apparatus having excellent productivity and economy can be obtained.

  In the above description, the transfer position of the transfer conveyance belt 17 is described as being aligned in the vertical direction, but this is an example, and the transfer position may be aligned in any direction. For example, the waste toner collection boxes 20 may be arranged in the horizontal direction and disposed above. In that case, a larger amount of toner from the discharge port 10a or the like falls on the transfer / conveyance belt 17, so that the effect of reducing the frictional force can be further enhanced.

In the above description, the case where the belt transfer member is a transfer conveyance belt has been described as an example. However, the belt transfer member may be an intermediate transfer belt. The configuration in that case can be easily understood by those skilled in the art from the above description. For example, an intermediate transfer belt that transfers a toner image onto the surface is used in place of the transfer conveyance belt 17, and a transfer paper conveyance unit is provided in the vicinity of the driving roller 18 or the driven roller 19c. For example, the toner image on the belt can be transferred onto the transfer paper.
Even in this case, the same operational effects as described above are provided.

Further, in the above description, the belt transfer member cleaning unit is described as a blade-like member having good cleaning performance and relatively inexpensive, but may be a brush-like, roll-like, or pad-like member. Even in this case, there is an advantage that the frictional force at the contact portion can be reduced and the driving load of the belt transfer body can be reduced.
A blade-shaped member and these brush-shaped, roll-shaped, and pad-shaped members (hereinafter referred to as brush-shaped members) may be provided. By doing so, the cleaning load can be shared among them, so that the cleaning performance can be improved. In that case, since it can be comprised with the low-rigidity material which reduced the tensile elasticity modulus of the blade-shaped member, there exists an advantage that it can be made inexpensive. In that case, if it arrange | positions downstream of blade-shaped members, such as a brush-shaped member, there exists an advantage that it becomes easy to prevent the blade-shaped member from curling at the point that lubrication of the contact part of a blade-shaped member is accelerated | stimulated. In addition, if it is arranged on the upstream side, the toner on the belt transfer member is leveled by the brush-like member and the frictional force is more equalized, which makes it easier to prevent the blade-like member from curling. .

  In the above description, the example in which the bias voltage is not applied to the belt transfer member cleaning unit has been described. However, for example, the cleaning performance may be improved by applying a bias voltage. For example, if a bias voltage is applied to a brush-like member or the like, there is an advantage that the cleaning performance can be improved while reducing the contact pressure with the belt transfer member.

  In the above description, since there are a plurality of image forming units, the example of a color image forming apparatus having a particularly high space-saving effect has been described. However, the image forming unit may be a single monochrome image forming apparatus. Needless to say.

FIG. 2 is a schematic explanatory view of a front cross-sectional view for explaining a schematic configuration of a main part of the image forming apparatus according to the embodiment of the present invention.

Explanation of symbols

1 Color printer (image forming device)
2, 3, 4, 5 Image forming portions 2a, 3a, 4a, 5a Photosensitive drum (image carrier)
6, 7, 8, 9 Photoconductor cleaning units 6a, 7a, 8a, 9a Cleaning blade (image carrier cleaning means)
10, 11, 12, 13 Waste toner transport pipe (waste toner transfer means)
10a, 11a, 12a, 13a Discharge port 14 Transfer roller (transfer means)
17 Transfer conveyor belt (belt transfer body)
20 Waste toner collection box (waste toner collection container)
20a opening (opening)
21 Cleaning blade (belt transfer member cleaning means)
25 Transfer paper (recording material)

Claims (7)

An image forming apparatus for finally transferring a toner image formed on an image carrier to a recording material to form an image,
Image carrier cleaning means for removing toner remaining on the image carrier after the toner image is transferred from the image carrier;
A transfer means provided close to the image carrier, for sucking and transferring the toner image formed on the image carrier;
A belt transfer member comprising an endless belt whose surface is moved at the same linear velocity as the linear velocity of the image carrier between the transfer means and the image carrier;
Belt transfer member cleaning means for contacting the surface of the belt transfer member to remove deposits on the surface;
Waste disposed in the vicinity of the belt transfer body cleaning means and the belt transfer body, and capable of accommodating the deposits removed by the belt transfer body cleaning means and the toner removed by the image carrier cleaning means. A toner collection container;
Waste toner transfer means for transporting the toner removed by the image carrier cleaning means and discharging it into the waste toner collection container;
An image forming apparatus, wherein the toner discharged from the waste toner transfer unit is discharged to the vicinity of the belt transfer member on the upstream side of the belt transfer member cleaning unit.   The image forming apparatus according to claim 1, wherein the belt transfer member cleaning unit includes at least a blade-like member in contact with the belt transfer member.   The image forming apparatus according to claim 2, wherein the blade member has a tensile elastic modulus of 20 MPa or less.   The image forming apparatus according to claim 2, wherein the belt transfer body cleaning unit includes at least one of a brush-shaped member, a roll-shaped member, and a pad-shaped member.   At least one of the brush-shaped, roll-shaped, and pad-shaped members provided in the belt transfer body cleaning means can apply a bias voltage for sucking toner adhering to the belt transfer body. The image forming apparatus according to claim 4.   The image forming apparatus according to claim 1, wherein the waste toner collecting container has an opening facing the belt transfer body upstream of the belt transfer body cleaning unit.   A plurality of the image carrier, the image carrier cleaning unit, the transfer unit, and the waste toner transfer unit are provided, each of which forms a toner image with different color toners, and these toner images are finally recorded on the recording material The image forming apparatus according to claim 1, wherein a color image can be formed by being transferred in a color superimposed manner.

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