JP2009093086A - Transfer belt device and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transfer belt device which can stably run over a long period of time by preventing toner from being accumulated on a pressing member, etc. and the inside of an image forming apparatus from being contaminated due to the scattering of the toner, while preventing: the deviation due to the meandering, etc. of an intermediate transfer belt being an endless belt; and damage due to contact with a regulating member, etc. and to provide the image forming apparatus. <P>SOLUTION: The transfer belt device has: the pressing member 50 for regulating the deviation of the intermediate transfer belt 15 by a butting member 26 arranged in the end portion of a driving roller 20 stretching the intermediate transfer belt 15, in the end portion of the intermediate transfer belt 15, and for pressing in the vertical direction of the intermediate transfer belt 15 in at least one end portion of the belt; and a cleaning blade 31a for cleaning the toner on the intermediate transfer belt 15. The pressing member 50 has a tapered shape to the inside of the intermediate transfer belt 15. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a transfer belt apparatus and an image forming apparatus used for image formation such as a copying machine, a printer, and a fax machine, and more particularly to a transfer belt apparatus and an image forming apparatus using an intermediate transfer member.

In an image forming apparatus having an intermediate transfer member, it has been confirmed that when the belt tension of the intermediate transfer belt is increased, the color shift in the transfer process can be reduced. This is thought to be because the frictional force between the drive roller and the belt increases as the belt tension increases. Therefore, in the prior art, the belt tension has been secured by pressing a tension roller with springs attached to both ends against the belt.
However, this method has a problem that the belt tension cannot be increased due to the cracks at the end of the belt and the curl wrinkles. In addition, there is a problem in that the belt tension varies depending on the tolerances of the springs, and there is a difference in the left and right belt tension.
For example, it can be said that there is a solid difference in belt tension between an intermediate transfer member in which a tolerance upper limit spring is attached to both ends of the tension roller and an intermediate transfer member in which a tolerance lower limit spring is attached to both ends of the roller. Further, if one tolerance upper and lower limit springs are attached to both ends of the roller, a lateral deviation of the belt tension will occur. A normal spring has a larger tolerance as the applied pressure increases.For example, even if the belt can be released from the belt cracking and belt curl restrictions due to the belt depressurization method, etc., a high belt tension can be secured. As long as the belt tension is due to pressurization, a large solid difference or left-right deviation may occur. In the transfer belt drive device, axial deviation or meandering (meandering) occurs as the belt is driven, and the end portion of the belt is damaged, and the durability as a belt conveyance device and an image forming apparatus device using the belt end device is damaged. There is a problem that it cannot be secured.

  For this reason, for example, in Patent Document 1, the transfer conveyance belt is formed in an endless shape, is stretched between rollers driven to travel, and travels to a transfer position where the toner image on the image carrier is transferred. A guide member for preventing meandering is attached to the inner surfaces of both ends of the transfer conveyance belt so as to be guided by the end of the roller, and the electrical resistance value of the guide member is the electrical resistance value of the transfer means. A transfer device that is set to be the same is disclosed. In Patent Document 2, a plurality of roll members other than the driving roll are arranged to be tiltable, and the contact pressure of the endless belt with respect to each roll member is biased toward one end side in the axial direction by the tilting, thereby correcting the belt walk. An endless belt type conveying apparatus is disclosed. Patent Document 3 discloses an endless belt that prevents meandering by providing a guide that abuts against an edge of a roller that stretches the endless belt or a flange at the end of the roller.

  The transfer device disclosed in Patent Document 1 has a drawback in that the workability is poor because it is necessary to perform the work of attaching a rubber guide to a belt having poor handling properties. Further, since it is necessary to provide a guide groove for a rubber guide having a certain thickness on each of the tension rollers of the belt, there is a disadvantage that the roller diameter is increased, and the apparatus as a whole is increased. The endless belt type conveying device disclosed in Patent Document 2 requires complicated structures such as a belt meandering detecting unit and a roller inclination correcting unit, which has a drawback of increasing the cost and increasing the size of the entire apparatus. In the endless belt disclosed in Patent Document 3, the belt axial displacement force is excessive due to the positional tolerance deviation of each tension roller, the axial deviation of the belt tension, the axial deviation of the friction coefficient of each tension roller, and the like. Therefore, it is difficult to stably suppress the buckling of the belt end portion over a long period of time.

Japanese Patent No. 3523503 Japanese Patent No. 3223771 Japanese Patent No. 3837246

  By arranging the pressing member at the end of the belt, these problems can be solved, and the cost of the apparatus can be reduced by reducing the size of the entire apparatus and configuring the production workability with the minimum number of members. However, by disposing the pressing member, toner leaks from the end of the cleaner unit of the intermediate transfer belt and accumulates on the pressing member, causing toner scattering, and the inside of the unit having the intermediate transfer belt becomes dirty. As a result, the density and process of the image forming apparatus cannot be controlled due to contamination of the TM sensor light receiving part.

  Accordingly, the present invention has been made in view of the above problems, and the problem is that the intermediate transfer belt, which is an endless belt, is offset from meandering and the like, and is also prevented from being damaged due to contact with a regulating member. It is an object of the present invention to provide a transfer belt device and an image forming apparatus capable of stable running over a long period of time by preventing toner from being deposited on a pressing member or the like and toner scattering and contamination in the image forming apparatus.

The features of the present invention, which is a means for solving the above problems, are listed below.
The transfer belt device of the present invention regulates the deviation of the belt at the end of the endless belt by an abutting member disposed at the end of the roller that stretches the belt, and at least at the end on one side of the belt In the transfer belt device having a pressing member that presses the belt from the vertical direction and having a cleaning means for cleaning the toner on the belt, the pressing member has a tapered shape inside the belt. To do.
The transfer belt device according to the present invention is further characterized in that the toner moved from the pressing member toward the inside of the belt is collected by the cleaning means.
Further, in the transfer belt device of the present invention, the pressing member is disposed outside the image area, and the inner end of the belt is at the same position as the end of the cleaning unit or the cleaning unit. It is arrange | positioned inside the said belt rather than the edge part of this.
The transfer belt device according to the present invention further includes a toner holding portion that temporarily holds toner on the upstream side in the belt conveyance direction where the pressing member and the belt are in contact with each other.
Further, in the transfer belt device of the present invention, at least one of the pressing members is disposed on the abutting member or on the outer side of the abutting member at a portion fixed to the belt device and a portion in contact with the belt. It is characterized by that.
In the transfer belt device of the present invention, when the abutting member is driven by the roller, the abutting member is fixed to the abutting member from a portion fixed by a member outside the abutting member. And a portion in contact with the belt over the belt.
Further, in the transfer belt device according to the present invention, when the abutting member is not driven by the roller, the pressing member is arranged at a portion fixed on the abutting member and a portion contacting the belt. It is characterized by that.
The transfer belt device according to the present invention is further characterized in that the pressing member is a sliding member.
The transfer belt device according to the present invention is further characterized in that the pressing member is a felt member.

In the image forming apparatus of the present invention, at the end portion of the endless belt, the deviation of the belt is regulated by the abutting member disposed at the end portion of the roller that stretches the belt, and at least at the one end portion of the belt In the image forming apparatus having a transfer belt device having a pressing member for pressing the belt from the vertical direction and having a cleaning means for cleaning toner on the belt, the pressing member is tapered toward the inside of the belt. It is characterized by.
The image forming apparatus of the present invention is further characterized in that the toner that has moved from the pressing member toward the inside of the belt is collected by the cleaning means.
Further, in the image forming apparatus of the present invention, the pressing member is disposed outside the image area, and the inner end of the pressing member is located at the same position as the end of the cleaning unit or the cleaning unit. It is arrange | positioned inside the said belt rather than the edge part of this.
In addition, the image forming apparatus of the present invention further includes a toner holding unit that temporarily holds toner on the upstream side in the belt conveyance direction where the pressing member contacts the belt.
Further, in the image forming apparatus of the present invention, at least one of the pressing members is arranged on the abutting member or on the outside of the abutting member at a portion fixed to the belt device and a portion in contact with the belt. It is characterized by that.
In the image forming apparatus according to the aspect of the invention, when the abutting member is driven by the roller, the pressing member is fixed to the abutting member from a portion fixed by a member outside the abutting member. And a portion in contact with the belt over the belt.
Further, in the image forming apparatus of the present invention, when the abutting member is not driven by the roller, the pressing member is arranged at a portion fixed on the abutting member and a portion contacting the belt. It is characterized by that.
The image forming apparatus of the present invention is further characterized in that the pressing member is a sliding member.
The image forming apparatus of the present invention is further characterized in that the pressing member is a felt member.

  With the transfer belt device and the image forming device, the intermediate transfer belt, which is an endless belt, suppresses the meandering, the damage due to the contact with the regulating member, etc. Stable running over a long period of time has become possible by preventing toner from being scattered and contaminated in the apparatus.

  The best mode for carrying out the present invention will be described below with reference to the drawings. Note that it is easy for a person skilled in the art to make other embodiments by changing or correcting the present invention within the scope of the claims, and these changes and modifications are included in the scope of the claims. The following description is an example of the best mode of the present invention, and does not limit the scope of the claims.

FIG. 1 is a schematic diagram showing the configuration of the image forming apparatus of the present invention.
The photosensitive member 1 is a cylindrical photosensitive drum having a diameter of 24 mm, and rotates at a peripheral speed of 120 mm / s. A roller-shaped charging device 2 as charging means is pressed against the surface of the photosensitive member 1 and is driven to rotate by rotation of the photosensitive member 1, and a bias in which AC is superimposed on DC or DC by a high voltage power source (not shown). Is applied, the photoreceptor 1 is uniformly charged to a surface potential of -500V. Subsequently, the photosensitive member 1 is exposed to image information by an exposure unit 3 which is a latent image forming unit, and an electrostatic latent image is formed. This exposure process is performed by a laser beam scanner or LED using a laser diode.
The developing unit 4 is a one-component contact developing device that visualizes the electrostatic latent image on the photoreceptor 1 as a toner image by a predetermined developing bias supplied from a high-voltage power source (not shown). The developing device 4 stores an initial 180 g of one-component toner. This is a process unit 10 in which the photoreceptor 1, the charging device 2, and the developing device 4 are integrated.

Four process units 10 are arranged in parallel. When a full-color image is formed, a visible image is formed in the order of black, yellow, magenta, and cyan, and each color visible image is an endless belt that is in contact with each other. A full-color image is formed by sequentially transferring images onto the transfer belt 15. The intermediate transfer belt 15 is stretched by a drive / secondary transfer counter roller 21, a metal cleaning counter roller 16, a primary transfer roller 5, and a tension roller 20, and the drive roller 21 is driven by a drive motor (not shown). Are driven to rotate.
FIG. 2 is a perspective view showing the configuration of the drive roller and the intermediate transfer belt. FIG. 3 is a cross-sectional view from the front showing the configuration of the drive roller and the intermediate transfer belt. The belt tension is applied by springs on both sides of the tension roller 20. The tension roller 20 has an aluminum pipe shape with a diameter of 19 mm and an axial width of 231 mm. As shown in FIGS. 2 and 3, flanges 26 with a diameter of 22 mm are press-fitted into both ends, and the intermediate transfer belt 15 meanders. The abutting member that regulates The conveyance direction of the intermediate transfer belt 15 is the direction of the arrow in FIG.
As the driving roller 21, polyurethane rubber (thickness: 0.3 to 1 mm), thin layer coating roller (thickness: 0.03 to 0.1 mm), etc. can be used. A small urethane coating roller (thickness 0.05 mm, diameter 19 mm) was used.

  As the primary transfer member 5, a conductive blade, a conductive sponge roller, a metal roller, or the like can be used. In this embodiment, the primary transfer roller 5 is a metal roller having a diameter of 8 mm, and is intermediate to the photoreceptor 1. The offset arrangement was shifted by 8 mm in the moving direction of the transfer belt 15 and 1 mm in the vertical upward direction. A transfer electric field is formed via the intermediate transfer belt 15 by applying +500 to +1000 V in common as a predetermined transfer bias to the primary transfer roller 5 by a single high-voltage power supply (not shown) with respect to the photoreceptor 1. The toner image on the body 1 is transferred to the intermediate transfer belt 15. A toner mark sensor (TM sensor) 17 can be provided in the vicinity of the intermediate transfer belt 15 to measure the toner image density and each color position on the intermediate transfer belt 15 and adjust the image density and color matching. The toner amount is measured by the toner mark sensor 17 and the combination of the light emitting element and the light receiving element, but either a regular reflection type or a diffusion type sensor may be used.

  The intermediate transfer belt 15 is provided with an intermediate transfer belt cleaning unit 32. Cleaning is performed by scraping off the transfer residual toner on the intermediate transfer belt 15 by an intermediate transfer belt cleaning blade (hereinafter simply referred to as “cleaning blade”) 31. As a cleaning blade material, urethane rubber having a thickness of 1.5 to 3.0 mm and a rubber hardness (JIS A) of 65 to 80 ° is used, and is brought into counter contact with the intermediate transfer belt 15. The transfer residual toner thus scraped off is stored in the intermediate transfer member waste toner storage section 33 through a toner conveyance path (not shown). At least one of the portion corresponding to the cleaning nip portion of the intermediate transfer belt 15 or the edge portion of the cleaning blade 31 is coated with a coating agent such as a lubricant, toner, zinc stearate at the time of assembly. In addition to preventing the blade from rolling up, a dam layer is formed in the cleaning nip to improve the cleaning performance. Each roller that stretches the intermediate transfer belt 15 is supported from both sides of the intermediate transfer belt 15 by an intermediate transfer belt unit side plate (not shown).

The material used for the intermediate transfer belt 15 is PVDF (vinylidene fluoride), ETFE (ethylene-tetrafluoroethylene copolymer), PI (polyimide), PC (polycarbonate), TPE (thermoplastic elastomer), or the like. A resin film-like endless belt is used in which a conductive material such as carbon black is dispersed. In this embodiment, a single-layer structure in which carbon black is added to TPE having a tensile modulus of 1000 to 2000 MPa is used. An endless endless belt having a thickness of 90 to 160 μm and a width of 230 mm was used.
The resistance of the intermediate transfer belt 15 is a volume resistivity of 10 ⁸ to 10 ¹¹ Ωcm and a surface resistivity of 10 ⁸ to 10 ¹¹ Ω / □ in an environment of 23 ° C. and 50 RH% (both are HirestaUP MCP- manufactured by Mitsubishi Chemical Corporation). Measurement with HT450, application voltage 500V, application time 10 seconds are desirable.
When the volume resistivity and the surface resistivity of the intermediate transfer belt 15 exceed the above-described ranges, the intermediate transfer belt is charged. Therefore, it is necessary to take a measure such as setting the set voltage value higher as it goes downstream in the image forming order. Therefore, it becomes difficult to use a single power supply for the primary transfer unit. This is because the charge generated on the surface of the intermediate transfer belt 15 is increased due to the discharge generated in the transfer process, the transfer material peeling process, and the like, and self-discharge becomes difficult. Need arises. Also, if the volume resistivity and surface resistivity are below the above ranges, the charge potential decays quickly, which is advantageous for static elimination by self-discharge, but toner scatter occurs because the current during transfer flows in the surface direction. End up. Therefore, the volume resistivity and the surface resistivity of the intermediate transfer belt 15 in the present invention are within the above ranges.

In this image forming apparatus, the toner image from the intermediate transfer belt 15 is transferred to the transfer material 22 by the secondary transfer roller 25. The secondary transfer roller 25 covers a metal core such as SUS having a diameter of 6 mm with an elastic body such as urethane adjusted to have a resistance value of 10 ⁶ to 10 ¹⁰ Ω by a conductive material, thereby allowing a diameter of 19 mm, The width is 222 mm.
As the material, an ion conductive roller (urethane + carbon dispersion, NBR, hydrin), an electronic conductive type roller (EPDM) or the like is used. In this embodiment, the diameter is 20 mm and the Asker C hardness is 35 to 50 °. A urethane roller was used. Here, if the resistance value of the secondary transfer roller 25 exceeds the above range, it becomes difficult for the current to flow. Therefore, a higher voltage must be applied in order to obtain the required transfer property, resulting in an increase in power supply cost. . In addition, since it is necessary to apply a high voltage, discharge occurs in the gap before and after the nip of the transfer portion, and white spots are lost on the halftone image due to the discharge. This is remarkable in a low temperature and low humidity environment (for example, 10 ° C. and 015 RH%). On the other hand, if the resistance value of the secondary transfer roller 25 falls below the above range, the transferability between the multi-color image portion (for example, three-color superimposed image) and the single-color image portion existing on the same image cannot be achieved. This is because the resistance value of the secondary transfer roller 25 is low, so that a sufficient current flows to transfer the monochrome image portion at a relatively low voltage. However, it is optimal for the monochrome image portion to transfer the multiple color image portion. This is because a voltage value higher than the voltage is required, and setting a voltage that can transfer a plurality of color image portions causes an excessive transfer current in a single color image, resulting in a decrease in transfer efficiency.
The resistance value of the secondary transfer roller 25 is measured by placing the secondary transfer roller 25 on a conductive metal plate and applying a load of 4.9 N on one side to both ends of the core metal. And a current value that flows when a voltage of 1 kV is applied between the metal plate and the metal plate.

The transfer material 22 is fed by the paper feeding / conveying roller 23 and the registration roller pair 24 at the timing when the leading edge of the toner image on the surface of the intermediate transfer belt 15 reaches the secondary transfer position, and is transferred to a predetermined level by a high voltage power source (not shown). By applying a bias, the toner image on the intermediate transfer belt 15 is transferred to the transfer material 22. In this configuration, the paper feed takes a vertical path. The transfer material 22 is separated from the intermediate transfer belt 15 by the curvature of the secondary transfer counter roller 21, and the toner image transferred to the transfer material 22 is fixed by the fixing unit 40 and then discharged.
Further, in this embodiment, the process speed at the time of fixing is changed depending on the type of the transfer material 22. Specifically, when a transfer material 22 having a basis weight of 100 g / m ² or more is used, the process speed is halved, and the transfer material 22 passes through the fixing nip formed by the fixing roller / pressure roller pair. The toner image fixing property can be secured by passing through twice the normal process speed.

FIG. 4 is a schematic view showing the configuration of the transfer belt device of the present invention. As one embodiment of the present invention, as shown in FIG. 4, a part of a transfer belt device in which a pressing member 50 </ b> A having a taper shape in the inner transfer belt 15 is arranged is shown. Accordingly, the toner accumulated on the pressing member 50 </ b> A sequentially flows to the inside of the intermediate transfer belt 15. In addition, since the pressing member 50A is tapered inward, the toner does not collect more than a certain amount in the pressing member 50A, so that the toner can flow gradually to the inner side of the intermediate transfer belt 15, and the toner hardly collects in the pressing member 50A. , Can suppress scattering.
As the material of the pressing member 50A, an elastic body such as a rubber blade can be used in addition to sliding POM, sliding ABS, sliding sponge, felt material, etc., which are slidable resins.
Since it is necessary to secure an A4 paper horizontal size of 210 mm and a letter paper horizontal size of 216 mm or more as the image area on the intermediate transfer belt 15, the horizontal width of the pressing member 50A is set to 2 to 5 mm. Thereby, the buckling of the intermediate transfer belt 15 can be suppressed without disturbing the image, and the belt can be driven stably over a long period of time.

FIG. 5 is a schematic diagram showing the positional relationship between the pressing member and the intermediate transfer cleaning blade. As another embodiment, as shown in FIG. 5, the end of the pressing member 50B is outside the letter paper image area 60, and the end of the cleaning blade 31a of the intermediate transfer belt cleaning unit 31 is used. A part of the transfer belt device arranged so as to be inside the intermediate transfer belt 15 with respect to the portion is shown. As a result, the toner that has flowed from the pressing member 50 </ b> B to the inside of the intermediate transfer belt 15 is collected again by the intermediate transfer belt cleaning unit 31.
In particular, the end portion of the pressing member 50B is outside the letter paper image region 60, and toner can be reduced from contacting or staying in the flange 26 of the abutting member. However, since the cleaning blade 31a provided in the intermediate transfer cleaning unit 31 has to clean all the image areas and the outside thereof, the chance of toner contact with the flange 26 increases. Therefore, the pressing member 50B is arranged so as to be inside the intermediate transfer belt 15 with respect to the end of the cleaning blade 31a, and further has a tapered shape. As a result, the toner on the intermediate transfer belt 15 can be collected inside again and collected again by the intermediate transfer belt cleaning unit 31. The toner can be prevented from collecting and scattering on the pressing member 50B, and the cleaning unit 31 can collect the toner again, so that it is not necessary to add an extra mechanism and can be configured at low cost.
Even if the toner leaks from the end of the intermediate transfer belt cleaning unit 31, the pressing member 50 </ b> B is tapered inward so that the toner does not accumulate more than a certain amount in the pressing member 50 </ b> B, so that the toner is accumulated inside the intermediate transfer belt 15. The toner can be gradually flown, the toner hardly accumulates on the pressing member 50B, and scattering can be suppressed. By suppressing the occurrence of toner scattering due to accumulation on the pressing member 50B and the contamination inside the unit having the intermediate transfer belt, it is possible to suppress poor energization and contamination of the TM sensor light receiving portion. Therefore, the intermediate transfer belt 15 can travel stably over a long period of time.

FIG. 6 is a schematic view showing a configuration of a transfer belt device having a toner holding portion for temporarily holding. As another embodiment of the present invention, as shown in FIG. 6, the pressing member 50C has a toner holding portion for temporarily holding the toner, and the portion where the intermediate transfer belt 15 contacts is upstream of the intermediate transfer belt 15 in the conveyance direction. 2 shows a part of a transfer belt apparatus having a toner holding unit for temporarily holding toner. Thereby, scattering of the accumulated toner can be suppressed, and the toner can be efficiently flowed inward.
By creating a space between the pressing member 50C and the intermediate transfer belt 15, even if the toner scatters, the toner can be temporarily held in the space to prevent the toner from spreading outside the space.

FIG. 7 is a schematic diagram showing the configuration of a transfer belt apparatus provided with a guide member for fixing the pressing member to the intermediate transfer belt.
As another embodiment of the invention, as shown in FIG. 7, the pressing member 50D is provided on both sides of the end portion of the intermediate transfer belt 15 by guide members 51 fixed to a bearing 52 positioned outside the abutting member 26A. 2 shows a part of the transfer belt device provided in FIG. The pressing member 50D can be fixed to the intermediate transfer belt 15 by arranging the pressing member 50D beyond the abutting member 26A. As a result, buckling at the abutting member 26A, which is a shift regulating portion at the end of the intermediate transfer belt, can be suppressed by the pressing member 50D. The belt device and product life can be extended with an inexpensive and compact configuration.

FIG. 8 is a schematic view showing a configuration of a transfer belt device in which a guide member for fixing the pressing member to the intermediate transfer belt is provided on the sheet metal. Further, as shown in FIG. 8, the pressing member 50E is provided on both sides of the end portion of the intermediate transfer belt 15 by a guide member 51 fixed to a sheet metal 53 that supports the shaft of the driving roller 20 positioned outside the abutting member 26. Sometimes equipped. The sheet metal 53 is non-driven, and by installing the pressing member 50E at this location, buckling at the abutting member 26 which is a deviation regulating portion of the belt end can be suppressed.
Further, FIG. 9 is a schematic view showing a configuration of a transfer belt device in which a guide member for fixing the pressing member to the intermediate transfer belt is provided on the abutting member. In FIG. 9, the abutting member 26 </ b> B is configured so as not to be driven by the driving roller 20, and the pressing member 50 </ b> F is provided at the end of the intermediate transfer belt 15 by the guide member 51 fixed on the abutting member 26 </ b> B. It is provided on both sides of the. The guide member 51 is fixed with a snap hook, a screw, an adhesive, or the like. At least one pressing member 50 </ b> F is disposed at a portion in contact with the abutting member 26 and the intermediate transfer belt 15. By installing the pressing member 50F at the location of the abutting member 26B of the transfer belt device, it is possible to suppress buckling at the abutting member 26 that is a deviation regulating portion of the belt end.
By these, toner accumulates on the pressing member, and then the toner scatters, so that the inside of the transfer unit and the light receiving part of the TM sensor can be prevented from being contaminated, causing poor electrical conduction or a process error, and End buckling of the intermediate transfer belt 15 can be suppressed with a minimum configuration, and stable belt driving can be performed over a long period of time.

1 is a schematic diagram illustrating a configuration of an image forming apparatus of the present invention. FIG. 4 is a perspective view illustrating a configuration of a driving roller and an intermediate transfer belt. FIG. 3 is a cross-sectional view from the front showing the configuration of a drive roller and an intermediate transfer belt. It is the schematic which shows the structure of the transfer belt apparatus of this invention. FIG. 6 is a schematic diagram showing a positional relationship between a pressing member and an intermediate transfer cleaning blade. FIG. 3 is a schematic diagram illustrating a configuration of a transfer belt device having a toner holding unit that temporarily holds the toner. FIG. 3 is a schematic diagram illustrating a configuration of a transfer belt device in which a guide member for fixing a pressing member to an intermediate transfer belt is provided on a bearing. FIG. 4 is a schematic diagram illustrating a configuration of a transfer belt device in which a guide member for fixing a pressing member to an intermediate transfer belt is provided on a sheet metal. FIG. 4 is a schematic diagram illustrating a configuration of a transfer belt device in which a guide member that fixes a pressing member to an intermediate transfer belt is provided on an abutting member.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Photoconductor 2 Charging apparatus 3 Exposure apparatus 4 Developing apparatus 6 Photoconductor cleaning blade 8 Developing roller 9 Restriction blade 11 Supply roller 10 Process unit 15 Intermediate transfer belt 20 Driving roller 26 Abutting member 31 Intermediate transfer belt cleaning unit 31a Intermediate transfer belt Cleaning blade 50 Holding member 51 Guide member 52 Bearing 53 Sheet metal

Claims (18)

At the end of the endless belt, the pressing of the belt is regulated by the abutting member arranged at the end of the roller over which the belt is stretched, and the belt is pressed from the vertical direction of the belt at least at one end of the belt. In the transfer belt device having a member and having a cleaning means for cleaning the toner on the belt,
The transfer belt device, wherein the pressing member is tapered toward the inside of the belt. The transfer belt device according to claim 1, wherein the toner that has moved from the pressing member toward the inside of the belt is collected by the cleaning unit. The pressing member is disposed outside the image area, and the inner end of the pressing member is located at the same position as the end of the cleaning unit or the inner side of the belt from the end of the cleaning unit. The transfer belt device according to claim 2. The transfer belt device according to claim 1, further comprising a toner holding unit that temporarily holds toner on an upstream side in the belt conveyance direction where the pressing member contacts the belt. 2. The transfer according to claim 1, wherein at least one of the pressing members is arranged on a portion of the abutting member or outside of the abutting member at a portion fixed to the belt device and a portion in contact with the belt. Belt device. When the abutting member is driven by the roller, the pressing member is arranged from a portion fixed by a member outside the abutting member to a portion that contacts the belt beyond the abutting member. The transfer belt device according to claim 5, wherein The said pressing member is arrange | positioned in the part fixed on the said butting member, and the part which contacts the said belt, when the said butting member is non-following to the said roller. Transfer belt device. The transfer belt device according to any one of claims 1 to 7, wherein the pressing member is a sliding member. The transfer belt device according to claim 8, wherein the pressing member is a felt member. At the end of the endless belt, the pressing of the belt is regulated by the abutting member arranged at the end of the roller over which the belt is stretched, and the belt is pressed from the vertical direction of the belt at least at one end of the belt. In an image forming apparatus comprising a transfer belt device having a member and having a cleaning means for cleaning toner on the belt,
The image forming apparatus, wherein the pressing member has a tapered shape inside the belt. The image forming apparatus according to claim 10, wherein the toner that has moved from the pressing member toward the inside of the belt is collected by the cleaning unit. The pressing member is disposed outside the image area, and the inner end of the pressing member is located at the same position as the end of the cleaning unit or the inner side of the belt from the end of the cleaning unit. The image forming apparatus according to claim 11. The image forming apparatus according to claim 10, further comprising a toner holding unit that temporarily holds toner on an upstream side in the belt conveyance direction where the pressing member contacts the belt.
The at least one pressing member is disposed on the abutting member or on the outside of the abutting member at a portion fixed to the belt device and a portion contacting the belt. Image forming apparatus. When the abutting member is driven by the roller, the pressing member is arranged from a portion fixed by a member outside the abutting member to a portion that contacts the belt beyond the abutting member. The image forming apparatus according to claim 14, wherein the image forming apparatus is an image forming apparatus. The said pressing member is arrange | positioned in the part fixed on the said butting member, and the part which contacts the said belt when the said abutting member is non-following to the said roller. Image forming apparatus. The image forming apparatus according to claim 10, wherein the pressing member is a sliding member. The image forming apparatus according to claim 17, wherein the pressing member is a felt member.

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