JP2009134226A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a belt driving device capable of achieving stable traveling over a long term by suppressing deviation such as skewing of an endless belt, and further preventing contact with toner or accumulation of toner thereon, and to provide an image forming apparatus. <P>SOLUTION: The image forming apparatus includes: a flange 26 that is a butting member for pressing the outer peripheral surface of a belt near a part where the flange 26 and an intermediate transfer belt 15 come into contact with each other; and a belt cleaning blade 31 for removing residual toner on the intermediate transfer belt 15. The inside end of a pressing member 50 is more outside than the end of the belt cleaning blade 31 when viewed from a thrust direction of the pressing member 50, and further the belt cleaning blade 31 is provided with a toner seal material 31A at the end of the blade. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an image forming apparatus using an intermediate transfer member to which a toner image used for image formation, such as a copying machine, a printer, and a fax machine, or a recording belt to which a toner image is transferred is conveyed. .

When the endless belt is driven to rotate, there is a problem that axial deviation (meandering) occurs with the driving of the belt, the end of the belt is damaged, and the durability of the apparatus cannot be ensured. Even in the image forming apparatus, the endless belt uses an intermediate transfer member that transfers a toner image and a conveyance belt that conveys a recording member to which the toner image is transferred.
For example, 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, color misregistration 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.
Further, it can be said that there is a solid difference in belt tension between an intermediate transfer body in which a tolerance upper limit spring is attached to both ends of the tension roller and an intermediate transfer body 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.

  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

  SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and an object of the present invention is to achieve an image forming apparatus that achieves a reduction in cost by reducing the size of the entire apparatus and configuring a high productivity with a minimum number of members. Is to provide. Specifically, an image forming apparatus capable of stable running over a long period of time by preventing the endless belt from being meandered and the like and being damaged by contact with a regulating member, etc., and eliminating contact or retention with toner. Is to provide.

The features of the present invention, which is a means for solving the above problems, are listed below.
The image forming apparatus of the present invention includes an image carrier that carries a latent image, an exposure device that forms a latent image on the image carrier, and a toner that develops the electrostatic latent image formed on the surface of the image carrier. A developing device that makes a visible image, a transfer device that transfers a visible image on the surface of the image carrier to a recording member via an intermediate transfer member, and a cleaning device that cleans transfer residual toner on the image carrier. The image forming apparatus includes an abutting member disposed at an end of the roller to regulate the belt-side of the belt-shaped intermediate transfer member stretched by at least two rollers, and the abutting member. In the vicinity of the contact portion between the contact member and the belt, a pressing member that presses the outer peripheral surface of the belt and a belt cleaning member that removes residual toner on the belt are provided, and the inner end of the pressing member in the thrust direction is Than said end portion of the belt cleaning member, characterized in that on the outside.
In the image forming apparatus of the present invention, the belt cleaning member is a cleaning blade, and a toner seal material is provided at an end of the blade.
An image forming apparatus of the present invention includes an image carrier that carries a latent image, an exposure device that forms a latent image on the image carrier, and an electrostatic latent image formed on the surface of the image carrier via a developing member. In the image forming apparatus, the image forming apparatus includes: a developing device that develops the toner image with a toner and forms a visible image; In order to regulate the belt side of the belt-shaped intermediate transfer member stretched by at least two rollers, the apparatus is disposed in the vicinity of the abutting member disposed at the end of the roller and the contact portion between the abutting member and the belt. And a pressing member that presses the outer peripheral surface of the belt, and an inner end in the thrust direction of the pressing member is outside of at least one of the image carrier and the developing member.
In the image forming apparatus according to the aspect of the invention, the inner end in the thrust direction of the pressing member may be further outside the both ends of the outermost one of the image carrier and the developing member. And
The image forming apparatus of the present invention is further characterized in that the developing roller is provided with a toner seal material at an end.

The image forming apparatus according to the present invention further includes an image carrier cleaning member that removes toner adhering to the image carrier, and an inner end of the pressing member in a thrust direction is provided on the image carrier cleaning member. It is further outside the outer end.
The image forming apparatus of the present invention is further characterized in that a toner seal material is provided at an end of the image carrier cleaning member.
An image forming apparatus of the present invention includes an image carrier that carries a latent image, an exposure device that forms a latent image on the image carrier, and an electrostatic latent image formed on the surface of the image carrier via a developing member. A developing device that develops the toner and visualizes it, a transfer device that directly transfers the visible image on the surface of the image carrier to a recording member, a conveying belt that conveys the recording member, and an adhesion on the conveying belt. And a belt cleaning member that cleans the toner, the image forming apparatus includes a protrusion disposed at an end of the roller in order to regulate the belt shift of the conveying belt stretched by at least two rollers. A pressing member, and a pressing member that presses the outer peripheral surface of the belt in the vicinity of the contact portion between the butting member and the belt, and the inner end of the pressing member in the thrust direction is the belt cleaner. Characterized in that the outside than ring member.
In the image forming apparatus of the present invention, the belt cleaning member is a cleaning blade, and a toner seal material is provided at an end of the blade.

An image forming apparatus of the present invention includes an image carrier that carries a latent image, an exposure device that forms a latent image on the image carrier, and an electrostatic latent image formed on the surface of the image carrier via a developing member. An image forming apparatus comprising: a developing device that develops with toner and visualizes the image; a transfer device that transfers the visible image on the surface of the image carrier to a recording member; and a conveyance belt that conveys the recording member. The image forming apparatus includes an abutting member disposed at the end of the roller and a contact portion between the abutting member and the belt in order to regulate the belt of the conveying belt stretched by at least two rollers. And a pressing member that presses the outer peripheral surface of the belt, and an inner end in the thrust direction of the pressing member is outside of at least one of the image carrier and the developing member.
In the image forming apparatus according to the aspect of the invention, the inner end in the thrust direction of the pressing member may be further outside the both ends of the outermost one of the image carrier and the developing member. And
The image forming apparatus of the present invention is further characterized in that the developing roller is provided with a toner seal material at an end.
The image forming apparatus according to the present invention further includes an image carrier cleaning member that removes toner adhering to the image carrier, and an inner end of the pressing member in a thrust direction is provided on the image carrier cleaning member. It is further outside the outer end.
The image forming apparatus of the present invention is further characterized in that a toner seal material is provided at an end of the image carrier cleaning member.

  By the means to solve the above, in the image forming apparatus of the present invention, by installing the pressing member, it is possible to suppress buckling at the deviation regulating portion of the belt end, and extend the life of the belt with an inexpensive and small configuration. be able to. Further, it is possible to prevent the toner leaking from the end portion of the cleaning member or the like from colliding with a pressing member disposed downstream in the belt conveyance direction and causing toner scattering.

  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 device 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, applied voltage 500V, applied 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 serving as a recording medium is fed by a paper feeding / conveying roller 23 and a registration roller pair 24 at the timing when the front end of the toner image on the surface of the intermediate transfer belt 15 reaches the secondary transfer position. The toner image on the intermediate transfer belt 15 is transferred to the transfer material 22 by applying a predetermined transfer bias. 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 diagram illustrating a configuration of a pressing member that is disposed in the vicinity of the intermediate transfer belt and presses the outer peripheral surface of the intermediate transfer belt in an embodiment of the image forming apparatus of the present invention.
As an embodiment of the present invention, as shown in FIG. 4, a part of the image forming apparatus in which the pressing member 50 is arranged is shown, but the image forming apparatus is viewed from the front, and is pressed to the left as an example. Although the case where the member 50 is arrange | positioned is shown, it is also possible to arrange | position the pressing member 50 on the right side or both right and left. The holding member 50 is attached to the tip of the cradle 51. The pressing member 50 is disposed so as to press the end of the transfer intermediate transfer belt 15.
As the material of the pressing member 50, a sliding POM, a sliding ABS, or the like that is a slidable resin can be used for the contacting portion 50. As the image area on the intermediate transfer belt 15, it is necessary to secure an A4 paper horizontal size of 210 mm and a letter paper horizontal size of 216 mm or more. Therefore, the horizontal width of the pressing member 50 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 plan view showing the positional relationship between an intermediate transfer belt-shaped craning blade and a pressing member in an embodiment of the image forming apparatus of the present invention. As shown in FIG. 5, the inner end is located outside the end of the cleaning blade 31 when viewed from the thrust direction of the pressing member 50. The relationship between these end portions is indicated by a leader line. Thus, the position of the cleaning blade 31 on the transfer intermediate transfer belt 15 is slightly shifted in the thrust direction of the pressing member 50 so that the toner leaking from the side of the cleaning blade 31 does not hit the pressing member 50. It is to do.
FIG. 6 is a schematic diagram illustrating a configuration in which a cleaning blade is provided with a toner seal material in an embodiment of the image forming apparatus of the present invention. As shown in FIG. 6, the cleaning blade 31 is provided with a toner seal material 31A at the end thereof. The toner seal material 31 </ b> A can use a sponge material and has a function of preventing toner leakage from the end of the cleaning blade 31. However, toner having a diameter of 10 μm or less may leak from a slight gap between the cleaning blade 31 and the toner seal material 31A. At this time, when the leaked toner collides with the pressing member 50 positioned downstream of the intermediate transfer belt 15, the toner flies near the pressing member 50, and the inside of the image forming apparatus is contaminated. Therefore, as in the present embodiment, when the pressing member 50 is positioned outside the toner seal material 31A, the toner remains on the intermediate transfer belt 15, so that the inside of the image forming apparatus is not soiled. Similarly, this is true for all locations where toner may leak.

FIG. 7 is a schematic view showing the positions of the photosensitive member and the pressing member.
The photoconductor 1 is in contact with the intermediate transfer belt 15, but the inner end of the pressing member 50 is positioned outside the outer end of the photoconductor 1 when viewed in the thrust direction. The relationship between these end portions is indicated by a leader line. This is to prevent the toner transferred from the photoreceptor 1 to the intermediate transfer belt 15 from hitting the pressing member 50. When the toner contacts or stays on the pressing member 50, the frictional force with the intermediate transfer belt 15 changes, the axial direction of the intermediate transfer belt 15 is shifted, or the end of the intermediate transfer belt 15 is buckled. Prevent stable running over the period.

8, 9, 10, and 11 are schematic views showing one positional relationship in the thrust direction among the photosensitive member, the developing roller, and the belt pressing member.
The inner end of the pressing member 50 is positioned outside the outer end of the developing roller 8 when viewed in the thrust direction. The relationship between these end portions is indicated by a leader line. Thus, by preventing the toner transferred from the developing roller 8 to the intermediate transfer belt 15 from hitting the pressing member 50, the sliding force between the pressing member 50 and the intermediate transfer belt 15 changes, and the intermediate transfer belt is changed. Thus, it is possible to prevent the axial movement of 15 or buckling of the end portion of the intermediate transfer belt 15 and stable running over a long period of time. A small amount of toner may leak at the end of the developing roller 8 or the photoreceptor 1. At this time, when the leaked toner collides with the pressing member 50 located downstream of the intermediate transfer belt 15, the toner scatters in the vicinity of the pressing member, and the inside of the image forming apparatus 100 may be stained.
In FIG. 9, toner that is larger than the developing roller width and leaks from the end of the developing roller may collide with the pressing member 50, but leakage from the end of the photosensitive member does not collide. It is a configuration.
In FIG. 10, when the centers of the photosensitive member 1 and the developing roller 8 do not coincide with each other, there is a possibility that leakage from the developing roller 8 at the left end and leakage from the photosensitive member 1 at the right end may collide with each other. In this configuration, the toner leaking from both of the rollers 8 does not collide with the pressing member 50 at the same time.
In FIG. 11, both the photosensitive member 1 and the developing roller 8 are disposed inward of the pressing member 50 in the thrust direction, and the toner leaked from the end of the developing roller 8 and the photosensitive member 1 collides with the pressing member 50. It is the structure which did not have.
As in the present embodiment, when the pressing member 50 is positioned outside the toner seal materials 1A and 8A, the toner remains on the intermediate transfer belt 15, so that the inside of the image forming apparatus 100 is not soiled. Similarly, this is true for all locations where toner may leak.

FIG. 12 is a schematic view showing the positions of the toner seal material and the pressing member at the end of the developing roller.
As described above, not only the cleaning blade 31 but also a roller such as the developing roller 8 can be provided with a sealing material. As the seal member, a sponge agent can be used. By providing the toner seal member 8A on the developing roller 8, it is possible to prevent the toner from leaking and coming into contact with the pressing member 5. Further, the inner end of the pressing member 50 is outwardly viewed from the developing roller 8 in the thrust direction with respect to the inner end of the toner seal member 8A. It can run stably for a long time.

FIG. 13 is a schematic diagram showing the positions of the developer regulating blade and the pressing member in the developing device.
The inner end of the pressing member 50 is positioned outside the outer end of the regulating blade 9 when viewed in the thrust direction. The relationship between these end portions is indicated by a leader line. Thus, the toner transferred from the regulating blade 9 to the intermediate transfer belt 15 is prevented from hitting the pressing member 50, so that the sliding force between the pressing member 50 and the intermediate transfer belt 15 changes, and the intermediate transfer belt. Thus, it is possible to prevent the axial movement of 15 or buckling of the end portion of the intermediate transfer belt 15 and stable running over a long period of time.
FIG. 14 is a schematic diagram showing the positions of the toner seal material and the pressing member at the end of the regulating blade.
As described above, it is possible to provide not only a roller such as the developing roller 8 but also a blade. Therefore, by providing the toner sealing member 8A on the regulating blade 9, the toner leaks and contacts the pressing member 5. Can be suppressed. Further, the inner end of the pressing member 50 is positioned outside the regulating blade 9 when viewed in the thrust direction with respect to the inner end of the toner seal member 9A, thereby further preventing contact with the toner. It can run stably for a long time.

FIG. 15 is a schematic view showing the positions of the photosensitive member cleaning blade and the pressing member.
The inner end of the pressing member 50 is positioned outside the outer end of the photoconductor cleaning blade 6 as viewed in the thrust direction. The relationship between these end portions is indicated by a leader line. Thus, by preventing the toner transferred from the photoconductor cleaning blade 6 to the intermediate transfer belt 15 from hitting the pressing member 50, the sliding force between the pressing member 50 and the intermediate transfer belt 15 changes, and the intermediate This prevents the axial deviation of the transfer belt 15 or the buckling of the end of the intermediate transfer belt 15 and the occurrence of stable running over a long period of time.
FIG. 16 is a schematic view showing the positions of the toner seal material and the pressing member at the end of the photosensitive member cleaning blade 6.
As described above, it is possible to provide not only a roller such as the developing roller 8 but also a blade. Therefore, by providing the toner cleaning member 6A on the photosensitive member cleaning blade 6, the toner leaks and contacts the pressing member 5. Can be suppressed. Further, the inner end of the pressing member 50 is outside the toner cleaning member 6 when viewed in the thrust direction from the inner end of the toner seal member 6A, thereby further preventing contact with the toner, and the intermediate transfer belt. It is possible to run stably for 15 long periods.

FIG. 17 is a side view schematically showing the configuration around the photosensitive member. FIG. 18 is a side view schematically showing the configuration of the developing device.
In forming a visible image on the transfer material 22, a process of exposure, development, and transfer is performed. Part of the toner in the toner bottle (not shown) is attached to the supply roller 11, and the toner is put on the developing roller 8 as the rotation thereof. In order to keep the toner layer on the developing roller uniform, the regulating blade 9 scrapes off unnecessary toner on the developing roller. From the developing roller to which the toner has uniformly adhered, the toner moves onto the exposed photoreceptor 1, and a visible image can be formed from the latent image. The toner on the photoreceptor 1 is transferred to the transfer intermediate transfer belt 15 and transferred downstream to a transfer material such as paper.
Residual toner that has not been transferred to the intermediate transfer belt 15 passes through the entrance seal 12 and is scraped off by the photoreceptor cleaning blade 6. The scraped residual toner is stored as waste toner between the blade 6 and the entrance seal 12 and is transported to a waste toner tank by a transport screw (not shown). The end of the photoconductor 1, the end of the developing roller 8, the end of the regulating blade 9, the end of the photoconductor cleaning blade 6, and the end of the entrance seal 12 can all leak toner from the end. It has sex.

The developing roller 8, the regulating blade 9, and the photosensitive member cleaning blade 6 have toner seal materials 31A, 8A, 9A, and 6A at their ends, respectively. It is impossible to ensure that all the gaps are zero, and a gap of about 0.5 mm is generated. Since the particle size of the toner is on the order of several μm, a small amount of toner leaks from these gaps.
As in the embodiment of the present invention, each end of the developing roller 8, the regulating blade 9, the photoconductor cleaning blade 6, and the entrance seal, or each end of the developing roller 8, the regulating blade 9, and the photoconductor cleaning blade 6 is used. By disposing the pressing member 50 outside the inner end portions of the toner seal materials 31A, 8A, 9A, and 6A arranged in the thrust direction, it is possible to provide an image forming apparatus that does not stain the inside of the apparatus.
In addition, it is possible to collect the leaked toner in a waste toner bottle by setting the width of the cleaning blade to be larger than each toner leakage portion.

Further, FIG. 19 is a schematic diagram showing a configuration of an image forming apparatus which is one of the embodiments.
FIG. 19 is an overall configuration diagram showing an image forming apparatus embodying the present invention. Here, a color image forming apparatus is shown as an example. This color copying machine is a tandem type electrophotographic apparatus using an intermediate transfer belt 15, a paper feeding table 200 at the bottom, a copying machine main body 100 above it, and a scanner 300 and automatic document feeding at the top. A device (ADF) 400 is provided.
The image forming apparatus main body 100 is provided with a transfer device 5 having an endless intermediate transfer belt 15 in the substantially center. The intermediate transfer belt 15 is stretched by a driving roller 21 and driven rollers 20a and 20b, and is rotationally driven. To do. The image forming apparatus according to an embodiment of the present invention can be applied to the intermediate transfer belt 15 that transfers and superimposes toner images. On the left side of the drive roller 21, the belt cleaning device 32 removes residual toner remaining on the surface after image transfer to prepare for the next image formation. As a result, residual toner may not be completely cleaned and may remain on the intermediate transfer belt 15 and stain the image. These can be avoided.
Photosensitive members 1Y, 1M, 1C, 1K (hereinafter referred to as colors) are arranged above the linear intermediate transfer belt 15 spanned between the driving roller 21 and the driven rollers 20a, 20b along the moving direction. When there is no need to specify, the photosensitive member 1 is simply provided in a rotatable manner, and a known exposure device 3, developing device 4, charging device 2, and photosensitive member cleaning device 7 are provided around the photosensitive member 1. . Primary transfer rollers 1Y, 1C, 1M, and 1K constituting primary transfer means are provided. In addition, a static eliminating device and a lubricant application device (not shown) are provided around the photosensitive member 1, respectively, and these constitute one image forming unit 10.

On the other hand, a secondary transfer device 35 constituting a secondary transfer unit is provided below the intermediate transfer belt 15. The secondary transfer device 35 is configured to press the intermediate transfer belt 15 and contact the driven roller 26. The secondary transfer device 35 collectively transfers the toner images on the intermediate transfer belt 15 onto a sheet P as a recording medium fed between the intermediate transfer belt 15.
On the downstream side of the secondary transfer device 35 in the paper conveyance direction, there is provided a fixing device 40 for fixing the toner image formed on the paper P to the endless fixing belt by heating and pressure contact with a pressure roller. The sheet P after the image transfer is transported to the fixing device 40 by an endless transport belt 38 spanned between the pair of rollers 36 and 37. The secondary transfer device 35 may be a transfer system using a transfer roller or a non-contact charger. A paper reversing device for reversing the paper P when an image is formed on both the front and back sides of the paper is provided below the secondary transfer device 35. Note that the image forming apparatus according to an embodiment of the present invention can be applied to the conveyance belt 38 that conveys the sheet P as a recording member to the fixing device 40.

When making a color copy with a color copying machine having the above-described configuration, a document is usually set on the document table of the automatic document feeder 400. However, when a document is manually set, automatic document copying is performed. The feeding device 400 is opened, an original is set on the contact glass of the scanner 300, and the original is pressed against the contact glass by closing the automatic document feeding device 400.
Next, when a start switch (not shown) is pressed, when the document is set on the automatic document feeder 400, the document is automatically fed onto the contact glass. When the document is manually set on the contact glass, the scanner 300 immediately starts. Operates and starts running. As a result, the light from the light source is emitted toward the original, and the direction of the original is changed by 180 degrees by the pair of mirrors and incident on the reading sensor through the joint lens.
Further, when the start switch is pressed, the intermediate transfer belt 15 starts rotating, and at the same time, the photosensitive members 1Y, 1C, 1M, and 1K also start rotating and yellow, magenta, and cyan on the respective photosensitive members 1. Each monochrome image of black is formed. Each single-color image formed on each photoconductor in this way is superimposed and sequentially transferred onto the intermediate transfer belt 15 that rotates in the clockwise direction in FIG. 17 to form a full-color composite color image.

  On the other hand, the paper feed roller 23 of the selected paper feed stage in the paper feed table 200 rotates, and the paper P is fed out from the selected paper feed tray 22 in the paper feed unit, and is separated into one sheet by a separation roller (not shown). It is separated and conveyed to the conveyance guide plate. The fed paper P is transported to the copying machine main body 100 by the transport roller, contacts the registration roller 24, and temporarily stops. In the case of manual feed, the paper P set on the manual feed tray is fed out by the rotation of the paper feed roller, separated into one sheet by the separation roller, and conveyed to the manual feed path, to the registration roller 24. It abuts and temporarily stops. In any case, the registration roller 24 starts to rotate at an accurate timing according to the color image on the intermediate transfer belt 15, and the paper P that has been stopped is placed between the intermediate transfer belt 15 and the secondary transfer roller 22. The color image is transferred onto the paper P by the secondary transfer device 35 described above. The sheet P on which the color image has been transferred is conveyed to the fixing device 40 by the secondary transfer device 35 having a conveying function, and is overheated and pressurized to fix the transferred image. As a result, the paper is discharged onto the paper discharge tray 57 and stacked.

In the present embodiment, the pressing range of the pressing member 50 of the belts 15 and 26 is preferably pressed in a wide range from the end of the belts 15 and 26 to the inside as much as possible in the thrust direction. This is because a stable pressing pressure can be applied by increasing the area. Increasing the width of the belts 15 and 26 to increase the holding area leads to an increase in the size of the image forming apparatus main body 100. It is important to press the belts 15 and 26 in as wide a range as possible without changing the belt width and to reduce the amount of toner colliding with the pressing member 50.
Further, since the regulating blade 9 is a member for regulating the amount of toner on the developing roller 8, it is designed to be shorter than the width of the developing roller 8. In order to suppress the torque of the developing roller 8, the length of the regulating blade 9 is preferably as short as possible without causing any trouble in image formation. The photoreceptor 1 needs to receive the toner on the developing roller 8 and is designed to be longer than the developing roller 8. The photosensitive member cleaning blade 6 of the photosensitive member 1 is designed to be shorter than the photosensitive member 1 and longer than the developing roller 8. The entrance seal 6A needs to store toner scraped off by the photoconductor cleaning blade 6, and is designed to be longer than the photoconductor cleaning blade 6 and shorter than the photoconductor 1. The length dimensions are designed in the order of regulating blade 9 ≦ developing roller 8 ≦ photoreceptor cleaning blade 6 ≦ entrance seal 6A ≦ photoreceptor 1.
The belts 15 and 26 are pressed against the photoconductor 1 with a constant pressure. If the width of the photoconductor 1 is smaller than the belt width, the belts 15 and 26 may be damaged at the end of the photoconductor 1. Therefore, the length dimension is designed so that the developing roller 8 ≦ the belt 15 and 26 ≦ the photoreceptor 1 in this order. The developing roller 8, the regulating blade 9, and the photoreceptor cleaning blade 6 may leak toner within a range of several millimeters from both ends to the outside.

It is difficult to completely eliminate the leakage from both ends in consideration of the toner particle size. By adding toner sealants 8A and 6A to the end of a roller such as the developing roller 8 or the photosensitive member cleaning blade 6, it is possible to limit the leakage range from both ends to within about 0.5 mm. Normally, toner seal materials 8A and 6A for toner are added to these portions.
When a belt that is easily damaged at the end is used as the belt material, the length of the pressing member 50 is designed to be long so that leakage collision from the developing roller 8 is avoided and leakage collision from the photosensitive member 1 blade is allowed. Is possible.
In addition, when a belt that does not easily break the end portion is used as the belt material, the length of the pressing member 50 is designed to be short so as to avoid the leakage collision between both the developing roller 8 and the photosensitive member cleaning blade 6, and the pressing member 50 is disposed outside thereof. The design to arrange is possible.

Further, FIG. 20 is a schematic diagram showing a configuration of an image forming apparatus which is one of the embodiments.
The image forming apparatus 100 forms a color image by directly superimposing a toner image on a sheet P that is a recording member. The image forming apparatus includes four color image forming units 10Y, 10M, 10C, and 10K of yellow (Y), magenta (M), cyan (C), and black (K), and a full color image is formed from these four colors. Form. The image forming sections for the respective colors are photoreceptors 1Y, 1M, 1C, and 1K that are image carriers, charging devices 2Y, 2M, 2C, and 2K, developing devices 4Y, 4M, 4C, and 4K, and cleaning devices 7Y and 7M. , 7C, 7K. In the case of a so-called cleanerless system, there is no need to provide the cleaning devices 7Y, 7M, 7C, and 7K. The photoconductors 1Y, 1M, 1C, and 1K of the respective colors are uniformly charged by the charging devices 2Y, 2M, 2C, and 2K, and light writing units 3Y, 3M, 3C, and 3K prepared for the respective colors emit light according to image signals. And the light is imaged on the photosensitive member to form an electrostatic latent image, and the electrostatic latent image is developed by the developing devices 3Y, 3M, 3C, and 3K for each color to form a toner image. .
The transfer belt 15 as a transfer material carrier is supported by a driving roller 20 and a driven roller 21 and moves in accordance with the rotation of the driving roller 20. On the other hand, the transfer material such as transfer paper set in the paper feed cassette 22 at the lower part of the apparatus is sent to the registration roller 7 along the conveyance path and temporarily stopped, and the image forming operations of the image forming units 10Y, 10M, 10C, and 10K After being sent out in time, it is electrostatically attracted to the transport transfer belt 15 by the suction means 11 and transported.
The toner images formed on the photoreceptors 1Y, 1M, 1C, and 1K are transferred to transfer means (transfer rollers) that are in contact with the surface of the transfer transfer belt 15 opposite to the surface on which the transfer material is electrostatically attracted. , Transfer brush, etc.) 5Y, 5M, 5C, 5K. The toner images formed on the photoreceptors 1Y, 1M, 1C, and 1K of the respective colors are sequentially transferred onto the transfer material by the transfer means 5Y, 5M, 5C, and 5K provided for the respective colors, and the toner images of all the colors are obtained. After the image is transferred, the transfer material is separated from the conveying transfer belt 15 by separation means (not shown) or curvature separation, and is fused and fixed by the heating roller and pressure roller of the fixing device 13 to complete a full color image. It is sent to the upper paper discharge unit. After the transfer material is separated, the transport transfer belt 15 is neutralized by a neutralizing unit (not shown), and the cleaning device 32 removes paper dust and toner adhering to the surface of the transport transfer belt 15 to prepare for the next image formation.

In the present embodiment, the pressing range of the pressing member 50 of the belt 15 is preferably pressed in a wide range from the end of the belt 15 to the inside as much as possible in the thrust direction. This is because a stable pressing pressure can be applied by increasing the area. Increasing the width of the belt 15 to increase the holding area leads to an increase in the size of the image forming apparatus main body 100. It is important to hold down the belt 15 as much as possible without changing the belt width and to reduce the amount of toner that collides with the holding member 50.
Further, since the regulating blade 9 is a member for regulating the amount of toner on the developing roller 8, it is designed to be shorter than the width of the developing roller 8. In order to suppress the torque of the developing roller 8, the length of the regulating blade 9 is preferably as short as possible without causing any trouble in image formation. The photoreceptor 1 needs to receive the toner on the developing roller 8 and is designed to be longer than the developing roller 8. The photosensitive member cleaning blade 6 of the photosensitive member 1 is designed to be shorter than the photosensitive member 1 and longer than the developing roller 8. The entrance seal 6A needs to store toner scraped off by the photoconductor cleaning blade 6, and is designed to be longer than the photoconductor cleaning blade 6 and shorter than the photoconductor 1. The length dimensions are designed in the order of regulating blade 9 ≦ developing roller 8 ≦ photoreceptor cleaning blade 6 ≦ entrance seal 6A ≦ photoreceptor 1.
The belt 15 is pressed against the photosensitive member 1 with a constant pressure. If the width of the photosensitive member 1 is smaller than the belt width, the belt 15 may be damaged at the end of the photosensitive member 1. The dimensions are designed so that the developing roller 8 ≦ the belt 15 ≦ the photoreceptor 1 in this order.

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. FIG. 3 is a schematic diagram illustrating a configuration of a pressing member that is disposed in the vicinity of the intermediate transfer belt and presses the outer peripheral surface of the intermediate transfer belt in an embodiment of the image forming apparatus of the present invention. FIG. 4 is a plan view showing a positional relationship between an intermediate transfer belt-shaped craning blade and a pressing member. 1 is a schematic diagram illustrating a configuration in which a cleaning blade includes a toner seal material in an embodiment of the image forming apparatus of the present invention. It is the schematic which shows the position of a photoreceptor and a pressing member. It is a schematic diagram showing one positional relationship in the thrust direction among a photoconductor, a developing roller, and a belt pressing member. It is a schematic diagram showing one positional relationship in the thrust direction among a photoconductor, a developing roller, and a belt pressing member. It is a schematic diagram showing one positional relationship in the thrust direction among a photoconductor, a developing roller, and a belt pressing member. It is a schematic diagram showing one positional relationship in the thrust direction among a photoconductor, a developing roller, and a belt pressing member. FIG. 4 is a schematic diagram illustrating positions of a toner seal material and a pressing member at an end portion of a developing roller. FIG. 6 is a schematic diagram illustrating positions of a developer regulating blade and a pressing member in a developing device. It is the schematic which shows the position of the toner seal material of a regulation blade edge part, and a pressing member. FIG. 3 is a schematic view showing positions of a photoreceptor cleaning blade and a pressing member. FIG. 4 is a schematic view showing positions of a toner seal material and a pressing member at an end portion of a photoconductor cleaning blade. FIG. 2 is a side view schematically showing a configuration around a photoconductor. It is a side view which shows the structure of a developing device roughly. 1 is a schematic diagram illustrating a configuration of an image forming apparatus that is one of the embodiments. FIG. 1 is a schematic diagram illustrating a configuration of an image forming apparatus that is one of the embodiments. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Photoconductor 2 Charging device 3 Exposure device 4 Developing device 6 Photoconductor cleaning blade 6A Toner seal member 7 Photoconductor cleaning device 8 Developing roller 8A Toner seal member 9 Regulating blade 9A Toner seal member 11 Supply roller 10 Process unit 15 Intermediate transfer belt 20 Tension roller 21 Driving / secondary transfer counter roller 26 Flange 31 Intermediate transfer belt cleaning blade 31A Toner seal member 35 Secondary transfer device 36, 37 Tension roller 38 Conveying belt 40 Fixing device 50 Holding member 51 Receiving base 100 Image forming device 200 Paper feed table 300 Scanner 400 Automatic document feeder (ADF)

Claims (14)

An image carrier for carrying a latent image;
An exposure apparatus for forming a latent image on the image carrier;
A developing device that develops the electrostatic latent image formed on the surface of the image carrier with toner and visualizes the image;
A transfer device for transferring a visible image on the surface of the image carrier to a recording member via an intermediate transfer member;
In an image forming apparatus comprising: a cleaning device that cleans transfer residual toner on the image carrier;
The image forming apparatus includes an abutting member disposed at an end of the roller in order to regulate a belt side of the belt-shaped intermediate transfer member stretched by at least two rollers.
In the vicinity of the contact portion between the butting member and the belt, a pressing member that presses the outer peripheral surface of the belt,
A belt cleaning member for removing residual toner on the belt, and
An image forming apparatus, wherein an inner end in a thrust direction of the pressing member is located outside an end of the belt cleaning member. The image forming apparatus according to claim 1,
The image forming apparatus, wherein the belt cleaning member is a cleaning blade, and a toner seal material is provided at an end of the blade. An image carrier for carrying a latent image;
An exposure apparatus for forming a latent image on the image carrier;
A developing device that develops the electrostatic latent image formed on the surface of the image bearing member with toner through a developing member to make a visible image;
A transfer device that transfers a visible image on the surface of the image carrier to a recording member via an intermediate transfer member,
The image forming apparatus includes an abutting member disposed at an end of the roller in order to regulate a belt side of the belt-shaped intermediate transfer member stretched by at least two rollers.
A pressing member that presses the outer peripheral surface of the belt in the vicinity of the contact portion between the abutting member and the belt; and
An image forming apparatus, wherein an inner end of the pressing member in a thrust direction is located outside of at least one of the image carrier and the developing member. The image forming apparatus according to claim 3.
An image forming apparatus, wherein an inner end in a thrust direction of the pressing member is further outside both ends of the outermost one of the image carrier and the developing member. The image forming apparatus according to claim 3 or 4,
The developing roller is provided with a toner seal material at an end thereof. The image forming apparatus according to claim 3.
An image carrier cleaning member for removing toner adhering to the image carrier;
An image forming apparatus, wherein an inner end of the pressing member in a thrust direction is further outside an outer end of the image carrier cleaning member. The image forming apparatus according to claim 6.
An image forming apparatus comprising a toner sealant at an end of the image carrier cleaning member. An image carrier for carrying a latent image;
An exposure apparatus for forming a latent image on the image carrier;
A developing device that develops the electrostatic latent image formed on the surface of the image bearing member with toner through a developing member to make a visible image;
A transfer device that directly transfers a visible image on the surface of the image carrier to a recording member;
A conveying belt for conveying the recording member;
A belt cleaning member for cleaning toner adhering to the conveyor belt;
In an image forming apparatus comprising:
The image forming apparatus includes an abutting member disposed at an end of the roller in order to regulate the belt shift of the conveying belt stretched by at least two rollers.
A pressing member that presses the outer peripheral surface of the belt in the vicinity of the contact portion between the abutting member and the belt; and
An image forming apparatus, wherein an inner end in a thrust direction of the pressing member is outside the belt cleaning member. The image forming apparatus according to claim 1,
The image forming apparatus, wherein the belt cleaning member is a cleaning blade, and a toner seal material is provided at an end of the blade. An image carrier for carrying a latent image;
An exposure apparatus for forming a latent image on the image carrier;
A developing device that develops the electrostatic latent image formed on the surface of the image bearing member with toner through a developing member to make a visible image;
A transfer device for transferring a visible image on the surface of the image carrier to a recording member;
In an image forming apparatus comprising a conveyance belt that conveys a recording member,
The image forming apparatus includes an abutting member disposed at an end of the roller in order to regulate the belt shift of the conveying belt stretched by at least two rollers.
A pressing member that presses the outer peripheral surface of the belt in the vicinity of the contact portion between the abutting member and the belt; and
An image forming apparatus, wherein an inner end of the pressing member in a thrust direction is located outside of at least one of the image carrier and the developing member. The image forming apparatus according to claim 10.
An image forming apparatus, wherein an inner end in a thrust direction of the pressing member is further outside both ends of the outermost one of the image carrier and the developing member. The image forming apparatus according to claim 10 or 11,
The developing roller is provided with a toner seal material at an end thereof. The image forming apparatus according to claim 10.
An image carrier cleaning member for removing toner adhering to the image carrier;
An image forming apparatus, wherein an inner end of the pressing member in a thrust direction is further outside an outer end of the image carrier cleaning member. The image forming apparatus according to claim 13.
An image forming apparatus comprising a toner sealant at an end of the image carrier cleaning member.

Images