JP2009181107A - Belt twist-correcting method and device, belt device, image-forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a belt twist-correcting method which corrects the twist of a belt without imposing a stress on the belt, and to also provide a device therefor, a belt device and an image-forming device. <P>SOLUTION: The belt twist-correcting device has an intermediate transfer belt 3, which is wound on a plurality of rollers 4, 5, 6 to travel, and corrects the twist of the intermediate transfer belt 3. In this case, one of the rollers is made to be an adjustment roller 5 which is movable in the axial direction and supported with its inclination possible, and the adjustment roller 5 is energized so that the intermediate transfer belt 3 may twist in advance in a direction when the intermediate transfer belt 3 travels. Then, an inclination-providing member 60, which can change an inclination angle of the adjustment roller 5 in response to the movement in the axial direction, is provided at one end of the adjustment roller 5, and the inclination-providing member 60 inclines the adjustment roller 5 to an angle which is proportional to the movement in the axial direction of the adjustment roller 5, the movement being caused by the twist of the intermediate transfer belt 3. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a belt deviation correction method and apparatus, a belt apparatus, and an image forming apparatus that have an endless belt that is wound and driven by a plurality of rollers and corrects the deviation of the endless belt.

  A belt device using an endless belt that is wound around a plurality of rollers and driven to travel, in particular, a wide endless belt, is known. In image forming apparatuses such as copiers, printers, and facsimiles, sheet conveying devices and photosensitive members are also known. Used in belt units, fixing devices and the like. In such a belt device, when the belt is deviated, there is a risk of causing a problem such as an image misalignment. For this reason, it is necessary to regulate or correct the deviation of the belt.

  Specifically, when regulating the deviation, a rubber guide rib is provided at the end of the back surface of the belt to restrict it with a roller end or groove, or a flange with the belt end surface provided directly at the end of the roller is provided for direct regulation. There is something to do.

  Further, in the method of correcting the belt shift, the rib on the back surface of the belt described in Patent Document 1 rotates as it passes between the contact bodies, and the roller shaft is tilted via the link mechanism. In this case, the roller is inclined by moving a rib or a belt end member provided at the end of the roller. In addition, as described in Patent Document 3, it has been proposed to provide a detection ring and tilt the roller shaft by using a driving torque generated when the belt end portion rides on.

Many proposals have been made and implemented in which a sensor is used to detect the position of the belt and a drive source is used to apply displacement to the roller shaft.
However, in the method of regulating the belt, the belt end run-up, guide rib peeling, belt end breakage, etc. due to variations in the amount of belt misalignment held by the device can contribute to determining the life of the device. It has become. In addition, in order to suppress the shift amount as much as possible, it is necessary to require high component accuracy, which increases the cost. Various methods for correcting belt misalignment as described above have been proposed so far to correct them. However, a method using a sensor and a roller shaft displacement using a drive source is costly and low. It is difficult to install the device in the popularization layer where costs are increasing.

  Therefore, a device using a mechanical link or the like has been proposed. In Patent Document 1 described above, since the link mechanism is complicated, there is a possibility that the target movement is not performed due to a loss of force generated until the operation of tilting the roller shaft. Moreover, in patent document 2, since the rib provided in the belt edge part or the edge part itself is received, there is a concern about stress on the belt. Since the running performance of the belt depends on the installation state, environment, and mode of the machine, the balance angle of the roller is corrected each time, so that stress is applied to the belt end portion and there is a problem in durability. Further, since a force is applied from the end face side of the belt, it is a disadvantageous in terms of rigidity.

  Further, in Patent Document 3, a method is used in which a member whose surface has a high friction coefficient is used to convert a belt shift into a rotational torque. A change in surface properties due to sudden dirt cannot be avoided, and there is a problem in reliability.

JP 2005-92153 A JP 2006-162659 A Japanese Patent No. 2937566

  SUMMARY OF THE INVENTION An object of the present invention is to provide a belt deviation correction method and apparatus, a belt apparatus, and an image forming apparatus capable of correcting the belt deviation without overcoming the above-described conventional problems and applying stress to the belt. .

  In order to achieve the above object, the present invention provides an endless belt that is wound around a plurality of rollers and driven to travel, and a belt shift correction method that corrects the belt shift of the endless belt. Is configured as an adjustment roller that is movable in the axial direction and supported to be tiltable, and when the belt travels through the adjustment roller, the belt is biased in advance in one direction, and the belt A belt misalignment correction method is proposed, in which the adjustment roller is moved in the axial direction when the belt is moved, and the inclination angle of the adjustment roller is balanced with the movement.

  In order to achieve the above object, the present invention provides an endless belt that is wound around a plurality of rollers and driven to travel, and a belt shift correction device that corrects the shift of the belt of the endless belt. One is an adjustment roller that is movable in the axial direction and supported so as to be tiltable, and when the belt travels to the adjustment roller, the belt is biased in advance in one direction, and one end of the adjustment roller An inclination imparting member capable of changing the inclination angle of the adjustment roller according to the movement in the axial direction is provided, and the inclination roller is inclined to an angle that balances the movement of the adjustment roller in the axial direction due to the deviation of the belt. A belt misalignment correction apparatus characterized by the above is proposed.

In the present invention, it is effective that the action of biasing the belt in one direction is inclined in a predetermined direction of the adjusting roller.
Furthermore, the present invention provides an adjustment roller end surface that is provided at a position where the inclination imparting member abuts on an adjustment roller end surface opposite to the belt approaching direction, and the inclination imparting member moves by a reaction force of the action of the belt approaching. It is effective to change the tilt angle of the adjustment roller by being pushed by the.

  Furthermore, the present invention is effective when the friction coefficient between the back surface of the belt and the movable adjustment roller surface is larger than the friction coefficient between the sliding portions in the adjustment roller axial direction during movement.

  In order to achieve the above object, the present invention provides a belt device using the belt deviation correcting device according to any one of claims 2 to 5, wherein the belt is a photosensitive belt used in an image forming apparatus. A characteristic belt device is proposed.

  In order to achieve the above object, the present invention provides a belt device using the belt deviation correcting device according to any one of claims 2 to 5, wherein the belt is an intermediate transfer belt used in an image forming apparatus. A characteristic belt device is proposed.

  In order to achieve the above object, according to the present invention, in the belt device using the belt deviation correcting device according to any one of claims 2 to 5, the belt is a transfer material conveying belt used in the image forming apparatus. A belt device is proposed.

  In order to achieve the above object, the present invention provides a belt device using the belt deviation correcting device according to any one of claims 2 to 5, wherein the belt is a fixing belt used in an image forming apparatus. A belt device is proposed.

  In order to achieve the above object, the present invention proposes an image forming apparatus using the belt device according to any one of claims 6 to 9.

  According to the present invention, since the belt deviation is corrected by using the movement of the roller by the reaction force approaching the belt, there is no need to touch the belt or to detect the deviation by a sensor, and the belt deviation is surely stable and low in cost. Corrections can be provided.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a schematic configuration diagram showing an example of an image forming apparatus configured as a printer. The image forming apparatus shown here includes a plurality of photoconductors arranged in a main body casing, and in the illustrated example, the first to first examples. Fourth four photoreceptors 1a, 1b, 1c, and 1d are provided. Toner images of different colors are formed on the respective photoreceptors. In the example shown in FIG. 1, a black toner image, a magenta toner image, and a cyan toner image are formed on these photoreceptors 1a, 1b, 1c, and 1d. And a yellow toner image are formed. Each of the photoconductors 1a, 1b, 1c, and 1d shown in FIG. 1 is formed in a drum shape, but an endless belt-like photoconductor that is wound around a plurality of rollers and driven to rotate can also be used. .

  An intermediate transfer belt 3 configured as an intermediate transfer member is disposed opposite to the first to fourth photosensitive members 1a, 1b, 1c, and 1d, and each of the photosensitive members 1a, 1b, 1c, and 1d is disposed on the intermediate transfer belt 3. It is in contact with the surface. The intermediate transfer belt 3 shown here is wound around support rollers 4, 5 and 6 and one of these support rollers, for example, the support roller 4 is driven by a drive device (not shown). The intermediate transfer belt 3 is rotationally driven in the direction of arrow A by driving the roller. The intermediate transfer belt 3 may have a multilayer structure or a single layer structure. However, if the intermediate transfer belt 3 is a multilayer structure, the base layer is made of, for example, a fluororesin, PVDF sheet, or polyimide resin with little elongation, and the surface is smooth such as a fluororesin. What is covered with a good coat layer is preferable. Moreover, if it is a single layer, what uses materials, such as PVDF, PC, a polyimide, is good.

  The configuration for forming toner images on the first to fourth photoconductors 1a, 1b, 1c, and 1d and the configuration for transferring the toner images onto the intermediate transfer belt 3 are all substantially the same. The only difference is the color of each toner image. Therefore, only the configuration and operation for forming a black toner image on the first photoreceptor 1a and transferring the toner image onto the intermediate transfer belt 3 will be described. The photoconductor 1a is rotationally driven in the clockwise direction in FIG. 1, and at this time, the surface of the photoconductor is irradiated with light from a static eliminator (not shown), and the surface potential of the photoconductor 1a is initialized. The initialized photoreceptor surface is uniformly charged by the charging device 8 to a predetermined polarity, in this example, a negative polarity. The charged surface is irradiated with a light-modulated laser beam L emitted from the exposure device 9, and an electrostatic latent image corresponding to the writing information is formed on the surface of the photoreceptor 1a. In the image forming apparatus shown in FIG. 1, an exposure apparatus 9 including a laser writing apparatus that emits a laser beam is used. However, an exposure apparatus having an LED array and an image forming unit can also be used.

  The electrostatic latent image formed on the photoreceptor 1a is visualized as a black toner image when it passes through the developing device 10. On the other hand, a transfer roller 11 is disposed inside the intermediate transfer belt 3 so as to be opposed to the photoreceptor 1a with the belt interposed therebetween. The transfer roller 11 is in contact with the back surface of the intermediate transfer belt 3 to ensure an appropriate transfer nip between the photosensitive member 1a and the intermediate transfer belt 3.

  The transfer roller 11 is applied with a transfer voltage having a polarity opposite to the toner charging polarity of the toner image formed on the photoreceptor 1a, in this example, a positive polarity. As a result, a transfer electric field is formed between the photoreceptor 1a and the intermediate transfer belt 3, and the toner image on the photoreceptor 1a is electrostatically applied to the intermediate transfer belt 3 that is driven to rotate in synchronization with the photoreceptor 1a. Is transcribed. The transfer residual toner adhering to the surface of the photoreceptor 1a after the toner image is transferred to the intermediate transfer belt 3 is removed by the cleaning device 12, and the surface of the photoreceptor 1a is cleaned.

  In exactly the same manner, a magenta toner image, a cyan toner image, and a yellow toner image are respectively formed on the second to fourth photoreceptors 1b, 1c, and 1d, and the toner images of the respective colors are transferred to the black toner image. Electrostatic transfer is sequentially performed on the intermediate transfer belt 3 that has been formed.

  On the other hand, as shown in FIG. 1, a paper feeding device 14 is disposed in the lower part of the main body of the apparatus. Sent out. The fed recording medium P is a portion of the intermediate transfer belt 3 wound around the support roller 4 by a registration roller pair 16 at a predetermined timing, and a secondary transfer roller 17 which is an example of a transfer device placed against the portion. It is sent between. At this time, a predetermined transfer voltage is applied to the secondary transfer roller 17, whereby the composite toner image on the intermediate transfer belt 3 is secondarily transferred to the recording medium P.

  The recording medium P onto which the composite toner image has been secondarily transferred is further conveyed upward and passes through the fixing device 18, and at this time, the toner image on the recording medium P is fixed by the action of heat and pressure. The recording medium P that has passed through the fixing device 18 is discharged to the outside through the paper discharge unit 19. Further, the transfer residual toner adhering to the intermediate transfer belt 3 after the toner image transfer is removed by the cleaning device 20.

  Incidentally, in the image forming apparatus, the intermediate transfer belt 3 is constituted by a wide endless belt. When the intermediate transfer belt 3 is deviated from the belt, the image is displaced and the image quality is deteriorated.

  Therefore, the belt device having the intermediate transfer belt 3 includes a support roller 5 as a driven roller as an adjustment roller (hereinafter, the support roller 5 is referred to as an adjustment roller 5), and the adjustment roller 5 includes a belt deviation correction device. Yes. As shown in FIG. 2, the adjustment roller 5 of the present embodiment has a roller portion 51 and a roller shaft 52 fixed and integrated, the roller shaft 52 is rotatable on the side plate 21 via bearings 53 and 54, and It is slidably mounted in the axial direction. As shown in FIG. 3, the adjustment roller 5 has a roller part 51 and a roller shaft 52 that are separate from each other, the roller shaft 52 is fixed to the side plate 50, and the roller part 51 is connected to the roller shaft 52. On the other hand, it may be configured so as to be rotatable through the bearings 53 and 54 and to be slidable in the axial direction. Further, the belt width of the intermediate transfer belt 3 is such that the length in the axial direction of the roller portion 51 is considerably wider than the width of the intermediate transfer belt 3 so that both sides do not protrude from the movable range of the adjustment roller 5. Set. This is because the intermediate transfer belt 3 protrudes from the adjustment roller 5 as shown in FIG.

  Further, as shown in FIG. 5, one end side of the adjustment roller 5 is supported by a shaft support member 55, and the shaft support member 55 is rotatably attached to a side plate 50 not shown in the figure via a fulcrum 56. Yes. The shaft support member 55 is energized by the tension spring 57 in the counterclockwise direction around the fulcrum 56 to give a force to lower it, but one end side of the adjusting roller 5 is inclined as described in detail later. It is supported by the applying member 60 and held in that position.

Next, a method for correcting the shift of the intermediate transfer belt 3 by the belt shift correction device of the present embodiment will be described.
In this method, the belt deviation is corrected using the force generated by the belt approaching. Therefore, as shown in FIG. 7, the intermediate transfer belt 3 forcibly generates a shift on the adjustment roller 5, so that the axis L of the adjustment roller 5 is arranged with an inclination (angle α) with respect to the horizontal line C in advance. To do. As a result, the intermediate transfer belt 3 rotates to move in the axial direction due to the shift at the position of the adjustment roller 5. For example, as shown in FIG. 7, when the right side in the drawing is lifted and arranged, the intermediate transfer belt 3 starts to move to the left side. At this time, as will be described in detail later, the adjustment roller 5 that is movable in the axial direction also starts to move as the intermediate transfer belt 3 moves. The adjustment roller 5 moves to the right side opposite to the belt by the reaction force of the movement due to the shift of the intermediate transfer belt 3. FIG. 8 is a graph showing the relationship between the movement of the intermediate transfer belt 3 and the movement of the adjustment roller 5. As is apparent from FIG. 8, when the intermediate transfer belt 3 moves in the positive direction due to the deviation, the adjustment roller 5 moves in the negative direction due to the reaction force.

  Next, the reason why the adjustment roller 5 moves along with the intermediate transfer belt 3 will be described. When the intermediate transfer belt 3 is actually wound around a plurality of shafts, if all the rollers are arranged in parallel, the intermediate transfer belt 3 is wound at a right angle with respect to the rollers. It is difficult to think of it geometrically. However, when each roller has a slight inclination from a parallel position (in fact, the parts have dimensional variations, and it is almost impossible to keep a complete parallel state by just making the parts). When the intermediate transfer belt 3 that is the endless intermediate transfer belt 3 is assumed to be a rigid body, it always enters each roller with a certain angle α °. In this case, the intermediate transfer belt 3 moves in the tan α axis direction with respect to the distance traveled in the conveyance direction of the intermediate transfer belt 3. However, when the two rollers are wound around the same roller diameter, the two approach angles are the same in the calculation, so the difference in the amount of movement in the axial direction is unlikely. It is desirable to use those having different diameters.

  As shown in FIGS. 5 and 6, the belt misalignment correction apparatus in the present embodiment is provided with a shaft support member 55, a tension spring 57, and an inclination imparting member 60 on the right side of the adjustment roller 5. The inclination imparting member 60 is rotatably supported by a side plate 50 (not shown) via a fulcrum 61 provided at the upper portion thereof, and a support long hole 62 extending in the vertical direction is formed at a substantially central portion. The width of the support long hole 62 is set to be the same as or slightly larger than the diameter of the roller shaft 52 of the adjusting roller 5, and the roller shaft 52 is passed through the support long hole 62.

  With this configuration, one end (the right side in FIG. 5) of the adjustment roller 5 is supported by the inclination imparting member 60 and can be held at a desired height position. That is, since the adjustment roller 5 is pushed downward by the tension spring 57, the roller shaft 52 can be held at a position where it is pressed against the lower end of the support long hole 62. Since the inclination imparting member 60 can rotate around the fulcrum 61, the inclination angle of the adjustment roller 5 is determined according to the inclination of the inclination imparting member 60.

  In the belt deviation correction device configured as described above, the inclination of the adjustment roller 5 is set in advance to an angle at which deviation occurs in the intermediate transfer belt 3 and is held by the inclination imparting member 60 prior to correction. For example, in the example shown in FIG. 5, the inclination of the adjustment roller 5 is set to a position L1 that is raised to the right from the horizontal axis C, and the adjustment roller 5 is held at the position by the inclination applying member 60.

  Next, when the intermediate transfer belt 3 is run, the belt moves to the left in the figure, and thereby the adjustment roller 5 moves to the right. At this time, the right end surface of the adjusting roller 5 is pushed against the inclination imparting member 60, and the inclination imparting member 60 is moved to a position where the pushing force due to the belt and the force to stay below the tension spring 57 balance. Rotates around the fulcrum 61. The intermediate transfer belt 3 can be rotated without causing a deviation by the balance between the two forces.

  Thus, in the present invention, the adjustment roller 5 is tilted in advance so that the intermediate transfer belt 3 is shifted, and the angle at which the inclination of the adjustment roller 5 is not generated using the shift of the intermediate transfer belt 3 generated thereby. It can be corrected to. Therefore, the configuration of the belt deviation correction device is simple and can be provided at low cost, and stable and good belt deviation correction can be obtained.

  In addition, since it is necessary to rotate the inclination imparting member 60 with the moving force of the adjustment roller 5 when implementing this belt deviation correction method, naturally the sliding load and force transmission of the inclination imparting member 60 are efficiently performed. Therefore, it is ideal to arrange the rotation fulcrum 61 of the inclination imparting member 60 perpendicularly to the roller shaft 52 of the adjustment roller 5 and the direction in which the adjustment roller 5 is lifted. Further, when the tilt applying member 60 is rotated, the moving force of the adjusting roller 5 is used. Therefore, when the adjusting roller 5 receives a force by the reaction force when the tilt applying member 60 is pressed, If the friction coefficient between the surface of the adjustment roller 5 and the back surface of the intermediate transfer belt 3 is too low than the friction coefficient of the shaft, only the movement of the adjustment roller 5 stops and the intermediate transfer belt 3 continues to move, thereby correcting the deviation. Does not work, resulting in damage to the intermediate transfer belt 3 and the apparatus. Therefore, the friction coefficient between the back surface of the intermediate transfer belt 3 and the roller surface needs to be higher than the friction coefficient between the adjustment roller 5 and its shaft. Therefore, it is desirable to use a material having a high grip force such as rubber for the surface of the adjusting roller 5.

  By the way, since the relationship between the movement of the intermediate transfer belt 3 due to the deviation and the movement of the adjustment roller 5 is actually due to various factors such as the rigidity and characteristics of the material, the deviation amount is not determined according to this calculation. Is roughly proportional to this value. Accordingly, the amount of movement of the intermediate transfer belt 3 of each roller in the axial direction changes if the approach angle of the intermediate transfer belt 3 to each roller is different. Therefore, when the adjustment roller 5 cannot move in the axial direction, the intermediate transfer belt 3. By sliding the back surface and the surface of each roller, the entire movement is settled to a certain amount of movement.

  Therefore, for example, if the tilt angle of the adjustment roller 5 is set so that the approach angle of the support roller 6 and the drive roller 4 in FIG. Since the intermediate transfer belt 3 is moved in the axial direction, the amount of movement of the intermediate transfer belt 3 in the axial direction differs between the other rollers 4 and 6 and the adjustment roller 5, and therefore moves in proportion to the difference.

  Actually, the amount of movement confirmed in the experiment is shown in the graph of FIG. Since it is difficult to finally derive the amount of movement at this time from calculation, the tilt angle of the adjusting roller 5 is set based on the phenomenon surface while changing the parameters in the experiment.

  As mentioned above, although preferable embodiment of this invention was described, this invention should not be limited only to the said embodiment. For example, in the above-described embodiment, the belt shift correction device for the intermediate transfer belt has been described. However, the present invention is not limited to the belt device using the intermediate transfer belt, but a belt device using a transfer material conveyance belt and a belt device using a fixing belt. It can also be applied to shift correction.

1 is a schematic configuration diagram illustrating an embodiment of an image forming apparatus to which the present invention is applied. It is explanatory drawing which shows the adjustment roller which can move to an axial direction. It is explanatory drawing which shows the adjustment roller of other embodiment which can move to an axial direction. It is explanatory drawing explaining the relationship which the problem of an adjustment roller and a belt produces. It is a perspective view which shows the belt deviation correction apparatus which concerns on this invention. FIG. 6 is a side view showing the belt deviation correcting device of FIG. 5. It is explanatory drawing explaining the relationship between the inclination of a roller, and the belt side. 6 is a graph showing the relationship between the movement of the intermediate transfer belt and the movement of the adjustment roller.

Explanation of symbols

3 Intermediate transfer belt 5 Adjustment roller 55 Shaft support member 57 Tension spring 60 Tilt imparting member

Claims (10)

In a belt deviation correction method that has an endless belt that is wound around a plurality of rollers and driven to travel, and corrects the deviation of the endless belt,
One of the rollers is configured as an adjustment roller that can be moved in the axial direction and supported so as to be tiltable. When the belt travels through the adjustment roller, the belt is biased in advance in one direction. And
A belt misalignment correction method comprising: driving the belt; moving the adjusting roller in an axial direction when the belt approaches; and determining an inclination angle of the adjusting roller that balances the movement. In a belt deviation correction device that has an endless belt that is wound and driven around a plurality of rollers, and corrects the deviation of the belt of the endless belt,
One of the rollers is an adjustment roller that is movable in the axial direction and supported so as to be tilted.
When the belt runs on the adjustment roller, the belt is biased in advance in one direction,
Provided at one end of the adjustment roller with an inclination imparting member capable of changing the inclination angle of the adjustment roller according to the movement in the axial direction;
A belt deviation correcting device, wherein the inclination imparting member inclines the adjustment roller at an angle commensurate with the axial movement of the adjustment roller due to the deviation of the belt.   3. The belt deviation correcting device according to claim 2, wherein the action in one direction in which the belt is biased in advance is tilted in a predetermined direction of the adjustment roller.   4. The belt deviation correcting device according to claim 2, wherein the inclination imparting member is provided at a position where the inclination imparting member comes into contact with an end face of the adjustment roller opposite to a direction in which the belt approaches in advance. A belt misalignment correction device, wherein the inclination angle of the adjustment roller is changed by being pushed by an end face of the adjustment roller that is moved by a reaction force.   5. The belt deviation correction device according to claim 2, wherein a friction coefficient between the back surface of the belt and the movable adjustment roller surface is a friction coefficient between sliding portions in the adjustment roller axial direction during movement. Belt misalignment correction device characterized by being larger. In the belt device using the belt deviation correcting device according to any one of claims 2 to 5,
A belt device, wherein the belt is a photosensitive belt used in an image forming apparatus. In the belt device using the belt deviation correcting device according to any one of claims 2 to 5,
A belt device, wherein the belt is an intermediate transfer belt used in an image forming apparatus. In the belt device using the belt deviation correcting device according to any one of claims 2 to 5,
A belt device, wherein the belt is a transfer material conveyance belt used in an image forming apparatus. In the belt device using the belt deviation correcting device according to any one of claims 2 to 5,
A belt device, wherein the belt is a fixing belt used in an image forming apparatus.   An image forming apparatus using the belt device according to claim 6.

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