JP2019128400A - Image formation device - Google Patents

Abstract

To make it hard to generate a trouble that a gap between a flexible seal member and a belt member is generated even if the belt member gets wrinkles.SOLUTION: A flexible seal member 33 is in contact with an intermediate transfer belt 8 (belt member) within an area of a virtual plane area M surrounded with an upstream side line segment S1 in which a secondary transfer counter roller 18 disposed at an upstream side of the flexible seal member 33 is in contact with the intermediate transfer belt 8, a downstream side line segment S2 in which a cleaning counter roller 19 disposed at a downstream side of the flexible seal member 33 is in contact with the intermediate transfer belt 8, one end side line segment S3 connecting one end side of an upstream side line segment S1 and one end side of a downstream side line segment S2, and the other end side line segment S4 connecting the other end side of the upstream side line segment S1 and the other end side of the downstream side line segment S2.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a belt device provided with belt members such as an intermediate transfer belt, a transfer belt, a transfer conveyance belt, and a photosensitive belt, and an image of a copying machine, a printer, a facsimile, or a complex machine including the belt device. It relates to a forming device.

  2. Description of the Related Art Conventionally, a belt device in an image forming apparatus such as a copying machine or a printer is known in which a cleaning device that removes and collects toner attached to a belt member (intermediate transfer belt) is installed (for example, patent Reference 1.).

Specifically, in the image forming apparatus disclosed in Patent Document 1, toner images respectively formed on a plurality of photosensitive drums are primarily transferred to be superimposed on the surface of an intermediate transfer belt (belt member). The toner image carried on the intermediate transfer belt is secondarily transferred to a sheet conveyed to the position of the secondary transfer nip. At this time, toner (non-transfer toner) which has not been secondarily transferred to the sheet remains on the surface of the intermediate transfer belt. Then, the toner remaining on the intermediate transfer belt is removed and collected by the cleaning device.
Here, on the inlet side (upstream side) of the casing of the cleaning device, an inlet seal member (a flexible seal member for sealing a gap with the intermediate transfer belt in order to prevent toner leakage from the cleaning device) ) Is installed. The inlet seal member is in close contact with and in contact with the intermediate transfer belt.

  On the other hand, in Patent Document 1, for the purpose of stabilizing the sealability by the inlet seal member installed in the cleaning device, the flexural rigidity of the free end root portion of the inlet seal member is higher than the flexural rigidity of the free end tip portion. A technique for forming a large film is disclosed.

  In the conventional belt device, the belt member may be wrinkled and a gap may be generated between the flexible seal member and the belt member. In addition, since the gap is generated as described above, the sealability by the flexible seal member may be reduced, and the toner may be leaked from the cleaning device.

  The present invention has been made to solve the above-mentioned problems, and even if wrinkles have occurred in the belt member, the problem that a gap is generated between the flexible seal member and the belt member is unlikely to occur. The object is to provide a belt member and an image forming apparatus.

  The image forming apparatus according to the present invention includes a belt member that is stretched and supported by a plurality of support members and moves in a predetermined movement direction, a cleaning member that removes toner adhering to the surface of the belt member, and the cleaning member And a flexible seal member that contacts the belt member on the upstream side in the movement direction, and the upstream of the plurality of support members in the movement direction with respect to the flexible seal member. An upstream line segment in which the upstream support member disposed on the side contacts the belt member, and a downstream support member disposed on the downstream side in the movement direction with respect to the flexible seal member among the plurality of support members. A downstream line segment in contact with the belt member, an end line segment connecting one end side of the upstream line segment and one end side of the downstream line segment, the other end side of the upstream line segment and the downstream line segment And the other end side line segment connecting the other end, in in the area of the virtual plane region enclosed, in which said flexible sealing member is brought into contact with the belt member.

  According to the present invention, it is possible to provide a belt member and an image forming apparatus in which a problem that a gap is not generated between the flexible seal member and the belt member is less likely to occur even if the belt member is wrinkled. it can.

1 is an overall configuration diagram illustrating an image forming apparatus according to an embodiment of the present invention. It is a block diagram which expands and shows a part of image forming part. FIG. 2 is a schematic view showing an intermediate transfer belt device and its vicinity. It is an enlarged view showing an intermediate transfer cleaning device and its vicinity. It is an enlarged view which shows a flexible sealing member. FIG. 5 is a schematic view showing a flexible seal member, a secondary transfer opposing roller, a cleaning opposing roller, and an intermediate transfer belt in the width direction. It is the schematic which shows a flexible seal member, a secondary transfer opposing roller, a cleaning opposing roller, and an intermediate transfer belt as a comparative example in the width direction. FIG. 13 is a schematic view showing a flexible seal member, a secondary transfer counter roller, a cleaning counter roller, and an intermediate transfer belt as a modification in the width direction.

  Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and the redundant description will be appropriately simplified or omitted.

First, the overall configuration and operation of the image forming apparatus 100 will be described with reference to FIGS.
FIG. 1 is a block diagram showing a printer as an image forming apparatus, and FIG. 2 is an enlarged view showing a part of the image forming unit.
As shown in FIG. 1, an intermediate transfer belt device 10 as a belt device is installed in the center of the image forming apparatus main body 100. Further, image forming units 6Y, 6M, 6C, 6K corresponding to the respective colors (yellow, magenta, cyan, black) are juxtaposed so as to face the intermediate transfer belt device 10 (intermediate transfer belt 8).

  Referring to FIG. 2, the image forming unit 6Y corresponding to yellow includes a photosensitive drum 1Y, a charging unit 4Y disposed around the photosensitive drum 1Y (photosensitive member), a developing unit 5Y, and a cleaning unit 2Y, It is comprised by the lubricant supply part 3, the static elimination part, etc. Then, an image forming process (charging step, exposure step, developing step, transfer step, cleaning step) is performed on the photosensitive drum 1Y, and a yellow image is formed on the photosensitive drum 1Y.

  The other three image forming units 6M, 6C, and 6K have substantially the same configuration as that of the image forming unit 6Y corresponding to yellow except that the color of the toner used is different. A corresponding image is formed. Hereinafter, description of the other three image forming units 6M, 6C, and 6K will be omitted as appropriate, and only the image forming unit 6Y corresponding to yellow will be described.

Referring to FIG. 2, photosensitive drum 1Y is driven to rotate counterclockwise by a main motor. Then, the surface of the photosensitive drum 1Y is uniformly charged at the position of the charging unit 4Y (a charging process).
Thereafter, the surface of the photosensitive drum 1Y reaches the irradiation position of the laser beam L emitted from the exposure unit 7, and the width direction at this position (the vertical direction in FIG. 1 and FIG. 2 and the main scanning direction). The electrostatic latent image corresponding to yellow is formed by the exposure scanning (the exposure process).

Thereafter, the surface of the photosensitive drum 1Y reaches a position facing the developing portion 5Y, and the electrostatic latent image is developed at this position to form a yellow toner image (developing process).
Thereafter, the surface of the photosensitive drum 1Y reaches a position facing the intermediate transfer belt 8 and the primary transfer roller 9Y, and the toner image formed on the surface of the photosensitive drum 1 at this position is the surface of the intermediate transfer belt 8. Primary transfer (this is a primary transfer step). At this time, a small amount of toner (untransferred toner) remains on the photosensitive drum 1Y.

Thereafter, the surface of the photosensitive drum 1Y reaches the position facing the cleaning unit 2Y, and the untransferred toner remaining on the photosensitive drum 1Y at this position is collected in the cleaning unit 2Y by the cleaning blade 2a (cleaning Process.)
Here, inside the cleaning unit 2Y, a lubricant supply unit 3 including a lubricant supply roller 3a, a solid lubricant 3b, a compression spring 3c, and the like is provided. Then, the lubricant is scraped little by little from the solid lubricant 3b by the lubricant supply roller 3a rotating clockwise in FIG. 2, and the lubricant is supplied to the surface of the photosensitive drum 1Y by the lubricant supply roller 3a. It will be.
Finally, the surface of the photosensitive drum 1Y reaches a position facing the neutralization unit, and the residual potential on the photosensitive drum 1 is removed at this position.
Thus, a series of imaging processes performed on the photosensitive drum 1Y are completed.

The above-described image forming process is performed similarly to the yellow image forming unit 6Y in the other image forming units 6M, 6C, and 6K. That is, the laser beam L based on the image information is emitted onto the photosensitive drums 1M, 1C, and 1K of the image forming units 6M, 6C, and 6K from the exposure unit 7 disposed above the image forming unit. Is done. Specifically, the exposure unit 7 emits laser light L from a light source, and irradiates the photosensitive drum through a plurality of optical elements while scanning the laser light L with a polygon mirror that is rotationally driven. Note that a plurality of LEDs arranged in the width direction may be used as the exposure unit 7.
Thereafter, the toner images of the respective colors formed on the photosensitive drums 1M, 1C, and 1K through the developing processes by the developing units 5M, 5C, and 5K are primarily transferred onto the intermediate transfer belt 8 as a belt member. . In this way, a color image is formed on the intermediate transfer belt 8.

Here, referring also to FIGS. 3 and 4, the intermediate transfer belt 8 is stretched and supported by roller members 16 to 23 as a plurality of support members, and one roller member (drive roller by drive motor (drive roller) 16) is a belt member that is moved endlessly in the direction of the arrow in FIG.
The four primary transfer rollers 9Y, 9M, 9C and 9K respectively sandwich the intermediate transfer belt 8 between the photosensitive drums 1Y, 1M, 1C and 1K to form a primary transfer nip. Then, a transfer voltage (primary transfer bias) having a polarity opposite to that of the toner is applied to the primary transfer rollers 9Y, 9M, 9C, and 9K.
Then, the intermediate transfer belt 8 moves in the moving direction indicated by the arrow, and sequentially passes through the primary transfer nips of the primary transfer rollers 9Y, 9M, 9C, and 9K. Thus, the toner images of the respective colors on the photosensitive drums 1Y, 1M, 1C, and 1K are superimposed on the surface of the intermediate transfer belt 8 and primarily transferred (this is a primary transfer step).

  Thereafter, the intermediate transfer belt 8 on which the toner images of the respective colors are primarily transferred is reached to the position opposite to the secondary transfer belt 72. At this position, the secondary transfer counter roller 18 sandwiches the intermediate transfer belt 8 and the secondary transfer belt 72 between the secondary transfer roller 70 and forms a secondary transfer nip. The four-color toner images formed on the intermediate transfer belt 8 are secondarily transferred onto a sheet P such as a sheet conveyed to the position of the secondary transfer nip (secondary transfer step). . At this time, toner (non-transferred toner) not transferred to the sheet P remains on the intermediate transfer belt 8.

Thereafter, the intermediate transfer belt 8 (belt member) reaches the position of the intermediate transfer cleaning device 30 as a cleaning device. At this position, deposits such as toner (untransferred toner) adhered to the surface of the intermediate transfer belt 8 are removed.
Further, the intermediate transfer belt 8 reaches the position of the lubricant supply device 35 (in the present embodiment, provided in the intermediate transfer cleaning device 30) shown in FIG. At this position, a lubricant is supplied to the surface of the intermediate transfer belt 8.
Thus, a series of transfer processes performed on the intermediate transfer belt 8 is completed.

Here, referring to FIG. 1, the sheet P conveyed to the position of the secondary transfer nip is fed from the sheet feeding unit 26 disposed below the apparatus main body 100 to the sheet feeding roller 27, the pair of registration rollers 28, etc. It is conveyed via.
In more detail, the sheet feeding unit 26 stores a plurality of sheets P such as transfer sheets in an overlapping manner. Then, when the paper feed roller 27 is rotationally driven in the counterclockwise direction in FIG. 1, the topmost sheet P is fed toward the space between the registration roller pair 28 via the first conveyance path K1. The

  The sheet P conveyed to the registration roller pair 28 (timing roller pair) temporarily stops at the position of the roller nip of the registration roller pair 28 whose rotational drive has been stopped. Then, the registration roller pair 28 is rotationally driven in synchronization with the color image on the intermediate transfer belt 8, and the sheet P is conveyed toward the secondary transfer nip. Thus, a desired color image is transferred onto the sheet P.

Thereafter, the sheet P on which the color image has been transferred at the position of the secondary transfer nip is conveyed by the secondary transfer belt 72 and separated from the secondary transfer belt 72, and then is moved to the position of the fixing unit 50 by the conveyance belt 60. Be transported. At this position, the color image transferred on the surface is fixed on the sheet P by the heat and pressure generated by the fixing belt and the pressure roller (fixing step).
Thereafter, the sheet P is discharged to the outside of the apparatus by the discharge roller pair via the second conveyance path K2. The sheet P discharged to the outside of the apparatus by the discharge roller pair is sequentially stacked on the stack unit as an output image.
Thus, a series of image forming operations (printing operations) in the image forming apparatus are completed.

  When “double-sided printing mode” for performing printing on both sides of the sheet P (the front side and the back side) is selected, the sheet P that has been subjected to the fixing process on the front side is described above. As in the case where the “single-sided printing mode” is selected, the paper is not discharged as it is, but is guided to the third transport path K3 and the transport direction is reversed, and then passes through the fourth transport path K4. The sheet is conveyed again to the position of the secondary transfer nip (secondary transfer device 69). Then, an image is formed on the back surface of the sheet P by an image forming process (image forming operation) similar to that described above at the position of the secondary transfer nip, and then a fixing process in the fixing unit 50 is performed. The recording medium is discharged from the image forming apparatus main body 100 via the second conveyance path K2.

Next, the configuration and operation of the developing unit 5Y (developing device) in the image forming unit will be described in more detail with reference to FIG.
The developing unit 5Y includes a developing roller 51Y facing the photosensitive drum 1Y, a doctor blade 52Y facing the developing roller 51Y, two conveyance screws 55Y disposed in the developer containing unit, and a toner concentration in the developer. A density detection sensor 56Y for detecting The developing roller 51Y is composed of a magnet fixed inside, a sleeve rotating around the magnet, or the like. In the developer accommodating portion, a two-component developer G composed of a carrier and a toner is accommodated.

The developing unit 5Y configured as described above operates as follows.
The sleeve of the developing roller 51Y rotates in the direction of the arrow in FIG. The developer G carried on the developing roller 51Y by the magnetic field formed by the magnet moves on the developing roller 51Y as the sleeve rotates. Here, the developer G in the developing unit 5Y is adjusted such that the ratio of the toner in the developer G (toner concentration) is within a predetermined range. Specifically, when a low toner concentration state is detected by the toner concentration sensor provided in the developing unit 5Y, new toner is contained in the developing unit 5Y from the toner container 58 so that the toner concentration falls within the predetermined range. To be replenished.
Thereafter, the toner replenished from the toner container 58 into the developer storage portion circulates through the two separated developer storage portions while being mixed and stirred together with the developer G by the two conveyance screws 55Y (FIG. 2 It is the movement in the direction perpendicular to the paper.) Then, the toner in the developer G is attracted to the carrier by the frictional charge with the carrier, and is carried on the developing roller 51Y together with the carrier by the magnetic force formed on the developing roller 51Y.

The developer G carried on the developing roller 51Y is conveyed in the direction of the arrow in FIG. 2 and reaches the position of the doctor blade 52Y. Then, the developer G on the developing roller 51Y is conveyed to the position facing the photosensitive drum 1Y (which is a developing area) after the amount of the developer is adjusted appropriately at this position. Then, the toner is attracted to the latent image formed on the photosensitive drum 1Y by the electric field formed in the development region. Thereafter, the developer G remaining on the developing roller 51Y reaches the upper portion of the developer accommodating portion as the sleeve rotates, and is detached from the developing roller 51Y at this position.
The toner container 58 is detachably (replaceable) with respect to the developing unit 5Y (image forming apparatus 100). The toner container 58 is removed from the developing unit 5Y (the image forming apparatus 100) and replaced with a new one when the new toner stored in the inside is exhausted.

Next, the intermediate transfer belt device 10 (belt device) according to the present embodiment will be described in detail with reference to FIGS.
Referring to FIG. 3, an intermediate transfer belt device 10 as a belt device includes an intermediate transfer belt 8 as a belt member, four primary transfer rollers 9Y, 9M, 9C, and 9K, a driving roller 16, a pre-transfer roller 17, The secondary transfer opposing roller 18, the cleaning opposing roller 19, the lubricant opposing roller 20, the tension roller 21, the backup roller 22, the driven roller 23, the intermediate transfer cleaning device 30 (cleaning device), the secondary transfer device 69, etc. The
The intermediate transfer belt 8 serving as a belt member is in contact with four photosensitive drums 1Y, 1M, 1C, and 1K that respectively carry toner images of respective colors to form a primary transfer nip. The intermediate transfer belt 8 mainly includes eight roller members (a drive roller 16, a pre-transfer roller 17, a secondary transfer opposite roller 18, a cleaning opposite roller 19, a lubricant opposite roller 20, a tension roller 21, a backup roller 22, and a driven roller 23. It is stretched and supported by.

In the present embodiment, the intermediate transfer belt 8 includes PVDF (vinylidene fluoride), ETFE (ethylene-tetrafluoroethylene copolymer), PI (polyimide), PC (polycarbonate), etc. in a single layer or multiple layers. It comprises, and electroconductive materials, such as carbon black, are disperse | distributed. The intermediate transfer belt 8 is adjusted so that the volume resistivity is in the range of 10 ⁶ to 10 ¹³ Ωcm and the surface resistivity on the back side of the belt is in the range of 10 ⁷ to 10 ¹³ Ωcm. The intermediate transfer belt 8 is set to have a thickness in the range of 20 to 200 μm. In the present embodiment, the thickness of the intermediate transfer belt 8 is set to about 60 μm, and the volume resistivity is set to about 10 ⁹ Ωcm.
A release layer may be coated on the surface of the intermediate transfer belt 8 as necessary. At that time, materials used for the coating are ETFE (ethylene-tetrafluoroethylene copolymer), PTFE (polytetrafluoroethylene), PVDF (vinylidene fluoride), PEA (perfluoroalkoxy fluororesin), FEP (four A fluororesin such as fluorinated ethylene-hexafluoropropylene copolymer) or PVF (vinyl fluoride) can be used, but is not limited thereto.

The primary transfer rollers 9Y, 9M, 9C, and 9K are in contact with the corresponding photosensitive drums 1Y, 1M, 1C, and 1K via the intermediate transfer belt 8, respectively. More specifically, the yellow transfer roller 9Y is in contact with the yellow photosensitive drum 1Y via the intermediate transfer belt 8, and the magenta transfer roller 9M is via the intermediate transfer belt 8 for the magenta photosensitive drum 1M. Contact roller, the cyan transfer roller 9C contacts the cyan photosensitive drum 1C via the intermediate transfer belt 8, and the black (black) transfer roller 9K passes the intermediate transfer belt 8 It is in contact with the photosensitive drum 1K for black (for black). The primary transfer rollers 9Y, 9M, 9C, and 9K are elastic rollers each having a conductive sponge layer formed on a core metal, and have a volume resistance of 10 ⁶ to 10 ¹² Ω (preferably 10 ⁷ to 10). ⁹ Ω).

  The drive roller 16 is positioned downstream of the four photosensitive drums in the moving direction of the intermediate transfer belt, and the inner transfer belt 8 is wound around the inner transfer belt 8 at a winding angle of about 120 degrees. It arrange | positions so that it may contact | abut on a surface. The driving roller 16 is rotationally driven in the clockwise direction in FIG. 3 by a driving motor. Thus, the intermediate transfer belt 8 moves (travels) in a predetermined moving direction (clockwise direction in FIG. 3).

  The driven roller 23 is located on the upstream side in the movement direction of the intermediate transfer belt 8 with respect to the four photosensitive drums, and the intermediate transfer belt 8 is wound around the intermediate transfer belt 8 at a winding angle of about 180 degrees. It arrange | positions so that it may contact | abut to a surrounding surface. In the intermediate transfer belt 8, the portion from the driven roller 23 to the drive roller 16 is set to be substantially horizontal. The driven roller 23 is driven to rotate clockwise in FIG. 3 as the intermediate transfer belt 8 moves.

The tension roller 21 is in contact with the outer peripheral surface of the intermediate transfer belt 8. The pre-transfer roller 17, the secondary transfer counter roller 18 (upstream support member), the cleaning counter roller 19 (downstream support member), the lubricant counter roller 20, and the backup roller 22 are in contact with the inner peripheral surface of the intermediate transfer belt 8. ing.
A cleaning blade 32 (cleaning member) is installed between the secondary transfer counter roller 18 and the lubricant counter roller 20 so as to contact the cleaning counter roller 19 via the intermediate transfer belt 8. The intermediate transfer cleaning device 30 provided with the cleaning blade 32 will be described in more detail later.
A lubricant supply device 35 (intermediate transfer lubricant supply device) is installed between the cleaning facing roller 19 and the tension roller 21 so as to come into contact with the lubricant facing roller 20 via the intermediate transfer belt 8. As shown in FIG. 4, the lubricant supply device 35 includes a lubricant supply roller 36, a solid lubricant 37, a compression spring 38, and the like, similarly to the lubricant supply unit 3 for the photosensitive drum. Then, the lubricant supply roller 36 that rotates counterclockwise in FIG. 4 scrapes the lubricant from the solid lubricant 37 little by little, and the lubricant is supplied to the surface of the intermediate transfer belt 8 by the lubricant supply roller 36. Will be.
All of the roller members 17 to 20, 22, and 23 except the driving roller 16 and the tension roller 21 are driven to rotate in the clockwise direction in FIG. 3 as the intermediate transfer belt 8 moves. The tension roller 21 is driven to rotate counterclockwise in FIG. 3 as the intermediate transfer belt 8 moves.

Referring to FIG. 3, the secondary transfer opposite roller 18 is in contact with the secondary transfer roller 70 via the intermediate transfer belt 8 and the secondary transfer belt 72. The secondary transfer counter roller 18 is an NBR having a volume resistance of about 10 ⁷ to 10 ⁸ Ω and a hardness (JIS-A hardness) of about 48 to 58 degrees on the outer peripheral surface of a cylindrical core metal made of stainless steel or the like. An elastic layer 83 (layer thickness is about 5 mm) made of rubber is formed.

  In the present embodiment, the secondary transfer counter roller 18 is electrically connected to a power supply unit, and a secondary transfer bias having a high voltage of about −5 kV is applied from the power supply unit. The secondary transfer bias applied to the secondary transfer counter roller 18 is used for secondary transfer of the toner image primarily transferred onto the surface of the intermediate transfer belt 8 onto the sheet P conveyed to the secondary transfer nip. It is a secondary transfer bias (DC voltage) having the same polarity as the polarity of the toner (minus polarity in the present embodiment). As a result, the toner carried on the toner carrying surface (outer circumferential surface) of the intermediate transfer belt 8 is electrostatically moved from the secondary transfer counter roller 18 side to the secondary transfer device 69 side by the secondary transfer electric field. Become. Although a DC voltage is used as the secondary transfer bias in the present embodiment, a combination of a DC voltage and an AC voltage can also be used as the secondary transfer bias.

Referring to FIG. 3, the secondary transfer device 69 includes a secondary transfer belt 72, a secondary transfer roller 70, a separation roller 71, a secondary transfer blade 73, and the like.
The secondary transfer belt 72 is an endless belt stretched and supported by a plurality of roller members (a secondary transfer roller 70 and a separation roller 71), and is formed of substantially the same material as the intermediate transfer belt 8. ing. The secondary transfer belt 72 is in contact with the intermediate transfer belt 8 to form a secondary transfer nip and conveys the sheet P sent from the secondary transfer nip.
The secondary transfer roller 70 forms a secondary transfer nip between the secondary transfer counter roller 18 and the intermediate transfer belt 8 and the secondary transfer belt 72.
The separation roller 71 is for separating (curvature separation) the sheet P conveyed along the secondary transfer belt 72 moving in the counterclockwise direction of FIG. 3 from the secondary transfer belt 72.
The secondary transfer blade 73 is in contact with the surface of the secondary transfer belt 72 and removes foreign matters such as toner and paper dust attached to the surface of the secondary transfer belt 72.

Hereinafter, the characteristic configuration and operation of the intermediate transfer belt device 10 as the belt device in the present embodiment will be described in detail.
As described above with reference to FIGS. 3 and 4, the intermediate transfer belt device 10 (belt device) according to the present embodiment includes an intermediate transfer belt 8 as a belt member and intermediate transfer cleaning as a cleaning device. A device 30 or the like is installed.
The intermediate transfer belt 8 (belt member) is stretched and supported by roller members 16 to 23 as a plurality of support members, and moves in a predetermined movement direction indicated by the arrows in FIGS. 3 and 4.

As shown in FIG. 4, the intermediate transfer cleaning device 30 (cleaning device) comprises a cleaning blade 32 as a cleaning member, a flexible seal member 33 (inlet seal), a lubricant supply device 35 and the like. .
The cleaning blade 32 is in contact with the surface of the intermediate transfer belt 8 at a predetermined angle and pressure, and functions as a cleaning member that removes toner (untransferred toner) attached to the surface of the intermediate transfer belt 8. The cleaning blade 32 is held by the housing 31 of the intermediate transfer cleaning device 30 via a holder. The cleaning counter roller 19 is in pressure contact with the cleaning blade 32 via the intermediate transfer belt 8.

The flexible seal member 33 is in contact with the intermediate transfer belt 8 on the upstream side in the moving direction with respect to the cleaning blade 32, as shown by a dashed line in FIG. The flexible seal member 33 is installed in the housing 31 of the intermediate transfer cleaning device 30 so as to seal a gap with the intermediate transfer belt 8.
More specifically, the flexible seal member 33 is downstream of the secondary transfer counter roller 18 as the upstream support member and upstream of the cleaning counter roller 19 as the downstream support member. The free end side is disposed in contact with the outer peripheral surface of the intermediate transfer belt 8 in the width direction. The base portion (fixed end side) of the flexible seal member 33 is attached to a holder 34 (a plate-like member formed of a metal material) held by the housing 31. The flexible sealing member 33 is a substantially rectangular sheet-like member made of foamed polyurethane or the like and having a thickness of about 0.1 to 1.5 mm.
As described above, by installing the flexible seal member 33 for sealing the gap with the intermediate transfer belt 8 at the opening on the inlet side (upstream side) of the case 31 of the intermediate transfer cleaning device 30, It is possible to reduce a problem that the toner (untransferred toner) collected in 31 leaks outside through the gap.

Referring to FIG. 5, in the present embodiment, the flexible seal member 33 is set so as to abut on the intermediate transfer belt 8 when the biting amount X is in the range of 0.1 to 3 mm. That is, the flexible seal member 33 is in close contact with and in contact with the intermediate transfer belt 8 with a bite amount X of about 0.1 to 3 mm.
The “biting amount X” is a position where the intermediate transfer belt 8 is planned to be placed in a state where the intermediate transfer belt 8 (belt member) is not in contact with the flexible seal member 33 (broken line in FIG. 5). The length X projected to the tip side from the) is referred to.
By setting the penetration amount X of the flexible seal member 33 in the above-described range, the sealability by the flexible seal member 33 is further improved.

Here, referring to FIG. 6, in the intermediate transfer belt device 10 (belt device) according to the present embodiment, the secondary transfer opposing as the upstream side supporting member among the plurality of roller members 16 to 23 (supporting member) A portion where the roller 18 (a roller member disposed on the upstream side in the movement direction with respect to the flexible seal member 33) contacts the intermediate transfer belt 8 is defined as an upstream line segment S1. Further, among the plurality of roller members 16 to 23 (support members), a cleaning facing roller 19 (a roller member disposed on the downstream side in the moving direction with respect to the flexible seal member 33) as a downstream support member. However, a portion in contact with the intermediate transfer belt 8 is referred to as a downstream line segment S2. Further, a portion connecting one end side of the upstream side line segment S1 and one end side of the downstream side line segment S2 is referred to as an end side line segment S3. Further, a portion connecting the other end side of the upstream line segment S1 and the other end side of the downstream line segment S2 is referred to as the other end side line segment S4. At this time, the flexible seal member 33 is the intermediate transfer belt in the area of the virtual plane area M surrounded by the upstream side line segment S1, the downstream side line segment S2, the one end side line segment S3, and the other end side line segment S4. The intermediate transfer belt device 10 is configured to abut on the belt 8.
That is, the contact portion of the flexible seal member 33 indicated by a broken line in FIG. 6 (a line segment that contacts the intermediate transfer belt 8) does not protrude from the virtual plane region M as shown in FIG. It will be within the plane area M.
In the virtual plane area M, the thickness of the intermediate transfer belt 8 is ignored. That is, when the virtual plane region M is formed on the inner peripheral surface side of the intermediate transfer belt 8, the virtual flat region M parallel moved by the belt thickness also exists on the outer peripheral surface side of the intermediate transfer belt 8. To do.

  With this configuration, even if wrinkles are generated in the intermediate transfer belt 8 and irregularities are formed on the surface of the intermediate transfer belt 8, there is no gap between the flexible seal member 33 and the intermediate transfer belt 8. As a result, the adhesion is impaired, and the sealability of the flexible seal member 33 is reduced, so that the problem of toner leakage from the intermediate transfer cleaning device 30 is less likely to occur.

In more detail, the intermediate transfer belt 8 is likely to be wrinkled because the balance of tension between the center in the width direction and the end in the width direction is broken at the positions of the one end side segment S3 and the other end side segment S4. Such a phenomenon is not limited to the relationship between the secondary transfer counter roller 18 and the cleaning counter roller 19, but occurs in the relationship between two adjacent roller members. Since the flexible seal member 33 is disposed between the cleaning opposed roller 19 and the sealability of the flexible seal member 33 is greatly influenced by the presence or absence of the wrinkles of the intermediate transfer belt 8, the problem that can not be ignored and Become. That is, as shown in FIG. 7, if the contact portion of the flexible seal member 33 is configured to overlap the one end side line segment S3 and the other end side line segment S4 that are likely to be wrinkled, one end side line segment is formed. A gap is formed between the flexible seal member 33 and the intermediate transfer belt 8 at a position corresponding to S3 and the other end side line segment S4, and toner leaks from the gap.
On the other hand, in the present embodiment, the contact portion of the flexible seal member 33 is configured so as not to overlap the one end side line segment S3 and the other end side line segment S4 that are likely to be wrinkled. Since the seal member 33 is in contact with the intermediate transfer belt 8 in a region (virtual plane region M) in which the intermediate transfer belt 8 is less prone to wrinkles, such a problem is less likely to occur.

In particular, in the present embodiment, the length D4 in the width direction of the intermediate transfer belt 8 is set so as to include the virtual plane region M described above.
That is, as shown in FIG. 6, the secondary transfer counter roller 18 (width direction range D1) and the cleaning counter roller 19 (width direction range D2) are included in the width direction range D4 of the intermediate transfer belt 8. It is configured to be.
By this configuration, the intermediate transfer belt 8 is unlikely to come off the secondary transfer opposite roller 18 or the cleaning opposite roller 19, but a portion which does not contact the secondary transfer opposite roller 18 or the roller portion of the cleaning opposite roller 19. Is necessarily formed, so that wrinkles of the one end side segment S3 and the other end side segment S4 are easily formed. Therefore, as described above, the effect of configuring the flexible seal member 33 to contact the intermediate transfer belt 8 in the virtual plane region M is easily exhibited.
Even when the intermediate transfer belt 8 is formed so that the width direction range D4 is included in the width direction range D1 of the secondary transfer counter roller 18 and the width direction range D2 of the cleaning counter roller 19. When the intermediate transfer belt 8 is shifted to a position where it reaches the position of the one end side line segment S3 or the other end side line segment S4, wrinkles will be generated at that position, meaning that the configuration of the present invention is applied. Is enough.

Here, as shown in FIG. 6, in this embodiment, the width of the cleaning counter roller 19 (downstream support member) is D1, where the length in the width direction of the secondary transfer counter roller 18 (upstream support member) is D1. When the length in the direction is D2, the length in the width direction of the flexible seal member 33 is D3, and the length in the width direction of the intermediate transfer belt 8 is D4,
D4>D1> D3
D4>D2> D3
D1 ≒ D2
The relationship is established.
This makes it easy to configure the flexible seal member 33 so as to contact the intermediate transfer belt 8 in the virtual plane region M by design.

<Modification>
FIG. 8 is a schematic view showing the flexible seal member 33, the secondary transfer opposing roller 18, the cleaning opposing roller 19 and the intermediate transfer belt 8 in the width direction of the intermediate transfer belt device 10 as a modification, FIG. 7 is a diagram corresponding to FIG. 6 in the embodiment.
As shown in FIG. 8, the intermediate transfer belt device 10 according to the modified example has a length in the width direction of the secondary transfer counter roller 18 (upstream support member) as D1, and the cleaning counter roller 19 (downstream support member). When the length in the width direction is D2, the length in the width direction of the flexible seal member 33 is D3, and the length in the width direction of the intermediate transfer belt 8 is D4,
D4>D1> D3
D4>D2> D3
Although the following relationship is established, the relationship of D12D2 is not established. Specifically, in the modification, the configuration is such that D1> D2.
Even in such a case, the flexible seal member 33 is intermediate in the area of the virtual plane area M surrounded by the upstream line segment S1, the downstream line segment S2, the one end side line segment S3, and the other end side line segment S4. By configuring to contact the transfer belt 8, the same effect as that of the present embodiment can be obtained.
In the modification example, although the relationship of D1> D2 is established, even when the relationship of D1 <D2 is established, the flexible seal member 33 is an intermediate in the virtual plane region M. By configuring the transfer belt 8 so as to abut, the same effect can be obtained.

As described above, the intermediate transfer belt device 10 (belt device) in the present embodiment is disposed upstream in the moving direction with respect to the flexible seal member 33 among the plurality of roller members 16 to 23 (support members). The secondary transfer counter roller 18 (upstream support member) thus made contacts the intermediate transfer belt 8 (belt member) with the upstream line segment S1 and the flexible seal member 33 among the plurality of roller members 16-23. A downstream cleaning line roller 19 (downstream support member) disposed on the downstream side in the moving direction connects the downstream line segment S2 in contact with the intermediate transfer belt 8, one end of the upstream line segment S1 and one end of the downstream line segment S2. A flexible seal member in the area of the virtual plane area M surrounded by the one end side line segment S3 and the other end side line segment S4 connecting the other end side of the upstream side line segment S1 and the other end side of the downstream side line segment S2. 33 is the intermediate transfer base. The door 8 is in contact with.
As a result, even if the intermediate transfer belt 8 is wrinkled, the problem that a gap is generated between the flexible seal member 33 and the intermediate transfer belt 8 can be prevented.

In the present embodiment, the intermediate transfer belt device 10 in which the intermediate transfer belt 8 as a belt member and the intermediate transfer cleaning device 30 as a cleaning device for removing toner adhering to the belt member are installed. The present invention was applied. On the other hand, a belt device provided with a photosensitive belt as a belt member, a transfer conveyance belt, a transfer belt, and a cleaning device for removing the toner attached to the belt member (for example, secondary in the present embodiment) Naturally, the present invention can also be applied to the transfer device 69.
Further, in the present embodiment, the present invention is applied to the image forming apparatus 100 that forms a color image. On the other hand, the present invention can also be applied to an image forming apparatus that forms only a monochrome image.
And even in such a case, the same effect as that of the present embodiment can be obtained.

  It should be noted that the present invention is not limited to the present embodiment, and it is obvious that the present embodiment can be modified as appropriate within the scope of the technical idea of the present invention, other than suggested in the present embodiment. is there. Further, the number, the position, the shape, and the like of the constituent members are not limited to the present embodiment, and the number, the position, the shape, and the like suitable for practicing the present invention can be set.

1Y, 1M, 1C, 1K photosensitive drum (photosensitive member),
8 Intermediate transfer belt (belt member),
10 Intermediate transfer belt device (belt device),
18 Secondary transfer counter roller (upstream support member),
19 Cleaning counter roller (downstream support member),
30 Intermediate transfer cleaning device (cleaning device),
31 housing,
32 Cleaning blade (cleaning member),
33 flexible seal member,
34 holder,
35 Lubricant supply device,
100 Image forming apparatus (image forming apparatus main body),
X bite amount,
S1 upstream line segment, S2 downstream line segment,
S3 one end side line segment, S4 other end side line segment,
M Virtual plane area.

JP, 2010-14834, A

Claims (7)

A belt member that is stretched and supported by a plurality of support members and moves in a predetermined movement direction;
A cleaning device comprising: a cleaning member that removes toner adhering to the surface of the belt member; and a flexible seal member that contacts the belt member on the upstream side in the movement direction with respect to the cleaning member;
With
Of the plurality of support members, an upstream line segment that is disposed on the upstream side in the movement direction with respect to the flexible seal member, and an upstream line segment in contact with the belt member; and among the plurality of support members, the flexible member End side line connecting a downstream line segment where the downstream side support member arranged on the downstream side in the moving direction with respect to the elastic seal member abuts the belt member, one end side of the upstream side line segment and one end side of the downstream side line segment And the other end side line segment connecting the other end side of the upstream line segment and the other end side of the downstream line segment, the flexible seal member is the belt member A belt device that abuts on the belt device.   The belt device according to claim 1, wherein a length in a width direction of the belt member is set to include the virtual plane area. The length in the width direction of the upstream support member is D1, the length in the width direction of the downstream support member is D2, and the width in the width direction of the flexible seal member is D3. When the length in the width direction is D4,
D4>D1> D3
D4>D2> D3
The belt device according to claim 1, wherein the following relationship is established. D1 ≒ D2
The belt device according to claim 3, wherein the following relationship is established. The cleaning member is a cleaning blade that contacts the surface of the belt member, and
The flexible seal member is installed in a housing of the cleaning device so as to seal a gap with the belt member,
The upstream support member is a roller member,
The belt device according to any one of claims 1 to 4, wherein the downstream support member is a roller member that presses against the cleaning blade via the belt member.   The belt device according to any one of claims 1 to 5, wherein the flexible seal member abuts on the belt member in a range of 0.1 mm to 3 mm.   An image forming apparatus comprising the belt device according to any one of claims 1 to 6.

Images