JP2017161877A - Belt device, transfer device, intermediate transfer device, and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a belt device comprising: belt colliding members that have the ends in the axial direction of a belt colliding thereto due to a movement in the axial direction of the belt and move in the axial direction together with the belt; a cleaning member that is arranged opposite to a roller including the belt colliding members; and sealing members, the belt device capable of preventing leakage of toner due to interference between the belt colliding members and sealing members, a transfer device, an intermediate transfer device, and an image forming apparatus.SOLUTION: In a belt device 60 comprising: a belt 3; belt colliding members 30 that can move in the axial direction of a rotation shaft 5a; a cleaning member 21 that removes attachment on the surface of the belt; and sealing members 22 that are arranged at the ends in the axial direction of the cleaning members, the belt colliding members and sealing members have a positional relationship where when the belt colliding members come closest to the ends in the axial direction of the sealing members, the belt colliding members are not in contact with the ends.SELECTED DRAWING: Figure 7

Description

  The present invention relates to a belt device, a transfer device, an intermediate transfer device, and an image forming apparatus.

  2. Description of the Related Art Conventionally, as a belt device provided with a belt that runs over a plurality of rollers (supporting rotating bodies), a belt control device that controls movement of the belt in the axial direction of at least one of the plurality of rollers has been provided. Things are known.

  For example, Patent Document 1 describes the following belt control device. That is, a belt abutting member movable in the axial direction of the roller and in contact with the belt end, and an axial displacement member provided on the outer side in the coaxial direction with respect to the belt abutting member and movably provided in the coaxial direction Is a belt control device provided on the rotating shaft of one roller. The belt abutting member is not fixed to the roller shaft, and is provided so as to freely rotate about the roller shaft. Further, the shaft displacement member has a slope on the outer side in the coaxial direction, and the slope is inclined so as to be located on the outer side in the coaxial direction as it approaches the rotation axis.

When the belt is deviated, the belt end abuts against the belt abutting member, and the belt abutting member moves outward in the coaxial direction by the abutting force. At this time, the belt abutting member rotates following the belt by frictional force with the belt end. Then, the belt abutting member comes into contact with the shaft displacement member and is abutted against the belt abutting member, and the shaft displacement member moves outward in the coaxial direction. It will be in the state which contacted the slope of the member. In this state, when the shaft displacement member further moves outward in the coaxial direction, the contact position between the slope of the shaft displacement member and the shaft guide portion is displaced upward along the slope of the shaft displacement member, and the shaft displacement member becomes a roller. The roller is tilted by pushing down the rotation shaft of the roller. By this tilting, the belt approaching one end of the roller can be moved in a direction to return the belt.
Further, in this belt device, a cleaning device provided with a blade member which is a cleaning member that comes into contact with the surface of the belt and removes deposits such as residual toner on the surface is disposed opposite to the inclined roller.

  In the belt device of Patent Document 1, a seal member is arranged to prevent residual toner removed by the blade member and collected in the casing of the cleaning device from leaking out of the cleaning device between the casing and the belt member. The presence or absence is not mentioned. If this seal member is disposed at the end of the blade member in the coaxial direction, the belt abutting member and the end of the seal member may interfere depending on the amount of movement of the belt in the roller axis direction. Specifically, when the belt moves in the direction to return the belt, the contact force of the belt end against the belt abutting member is weakened, and the rotational shaft is pushed up by the urging means provided on the rotational shaft, so that the axial displacement The contact position between the member and the shaft guide portion is displaced downward along the slope of the shaft displacement member. As a result, the shaft displacement member hits the belt abutting portion and moves the belt abutting portion toward the inner side in the coaxial direction. At this time, depending on the movement amount of the belt in the coaxial direction, the belt abutting portion moves to a position where the end of the seal member and the belt abutting member interfere with each other. If the seal member and the belt abutting member interfere with each other, the toner collected by the blade member may leak to the surroundings.

  Such a problem is not limited to the configuration in which the belt contact portion is driven by the belt member and rotates about the roller shaft, and the seal member is disposed in a movable range of the belt contact portion. This is a possible problem.

In order to achieve the above-described problems, the present invention provides a belt that is stretched over a plurality of support rotators and travels with the rotation of the plurality of support rotators, and at least one support of the plurality of support rotators. A belt abutting member which is provided on a rotating shaft of the rotating body and abuts against an end portion of the belt in the axial direction of the rotating shaft and which is movable in the axial direction, and is disposed to face the one supporting rotating body. In a belt device comprising: a cleaning member that removes the deposits; and a seal member disposed at an end in the axial direction of the cleaning member,
The belt abutting member and the seal member have a positional relationship in which the belt abutting member does not contact the end when the belt abutting member comes closest to the axial end of the seal member. It is characterized by that.

  According to the present invention, there is provided a belt abutting member that moves when the end of the belt abuts and moves together with the belt, a cleaning member that is disposed to face the roller having the belt abutting member, and a seal member. The belt device has an excellent effect that toner leakage due to interference between the belt abutting member and the seal member can be prevented.

1 is a schematic configuration diagram illustrating an example of a printer according to an embodiment. Explanatory drawing about the side seal provided in the belt cleaning apparatus with which the printer is equipped. The expanded sectional view of the shaft tilting mechanism of the shaft tilting mechanism immediately after the assembly. The expanded sectional view of the coaxial inclination mechanism after belt shift regulation. (A) is a schematic diagram when the structure of a coaxial inclination mechanism is seen from the axial direction of a tension roller. (B) is a schematic diagram when the structure of the shaft inclination mechanism after belt deviation regulation is viewed from the axial direction of the tension roller. The perspective view of the shaft inclination member in a coaxial inclination mechanism. Explanatory drawing about the positional relationship of the side seal and belt deviation detection member which concern on this embodiment. Explanatory drawing about the positional relationship of the side seal and belt deviation detection member in a comparative example.

Hereinafter, an embodiment in which the present invention is applied to a printer which is an electrophotographic image forming apparatus will be described with reference to the drawings.
FIG. 1 is a schematic configuration diagram illustrating an example of a printer 100 that is an image forming apparatus according to the present embodiment.
The printer 100 is provided with four photosensitive members 1a, 1b, 1c, and 1d that are latent image carriers disposed in the main body casing. Above the four photoconductors 1, an intermediate transfer device 60, which is a belt device including the intermediate transfer belt 3 as a belt member, is provided.

  Different color toner images are formed on the respective photoreceptors. Specifically, a black toner image, a magenta toner image, a cyan toner image, and a yellow toner image are formed on these photoreceptors 1a, 1b, 1c, and 1d, respectively. Note that each of the photoreceptors 1a, 1b, 1c, and 1d in the present embodiment is formed in a drum shape, but an endless belt-like photoreceptor that is wound around a plurality of rollers and driven to rotate can also be used.

  An intermediate transfer belt 3 as an endless belt-like member is disposed as an intermediate transfer member so as to face the four photosensitive members 1a, 1b, 1c, and 1d. The outer peripheral surfaces of the photoconductors 1a, 1b, 1c, and 1d are in contact with the outer peripheral surface of the intermediate transfer belt 3, respectively. The intermediate transfer belt 3 according to the present embodiment is wound and stretched around a support roller (support rotary body) such as a drive roller 4, a tension roller 5, a backup roller 6, and an entrance roller 7. The drive roller 4 which is one of these support rollers is rotationally driven by a drive source, and the intermediate transfer belt 3 travels in the direction of arrow A in the figure by the rotational drive of the drive roller 4.

  The intermediate transfer belt 3 may have a multilayer structure or a single layer structure. When the belt is composed of a multilayer structure, for example, it is preferable that the base layer is formed of a fluororesin, PVDF sheet, or polyimide resin with little elongation, and the belt surface is composed of a smooth coat layer such as a fluororesin. . On the other hand, when a belt having a single layer structure is used, a material such as PVDF, PC, or polyimide is preferably used.

  The configuration and operation for forming each color toner image on each photoconductor 1a, 1b, 1c, 1d and the configuration and operation for primary transfer of each color toner image onto the intermediate transfer belt 3 are substantially the same and formed. Only the color of each color toner image is different. Therefore, hereinafter, a configuration and operation for forming a black toner image on the black photoreceptor 1a and primarily transferring the toner image onto the intermediate transfer belt 3 will be described, and description of other colors will be omitted.

  The black photoconductor 1a is driven to rotate counterclockwise in FIG. The surface potential of the photosensitive member 1a is initialized by irradiating the outer peripheral surface of the photosensitive member 1a with light from the static eliminator. The initialized outer peripheral surface of the photoconductor is uniformly charged to a predetermined polarity (in this embodiment, a negative polarity) by the charging device 8a. The photosensitive member outer peripheral surface charged in this manner is irradiated with a light-modulated laser beam L emitted from an exposure device 9 serving as a latent image forming unit, whereby electrostatic latent images are formed on the outer peripheral surface of the photosensitive member 1a. An image is formed. In the present embodiment, the exposure apparatus that emits the laser beam L is configured by a laser writing apparatus. However, for example, an exposure apparatus having an LED array and an image forming unit may be used. The electrostatic latent image formed on the photoconductor 1a is visualized as a black toner image when passing through a developing area facing the developing device 10a as developing means.

  On the inner peripheral surface side of the intermediate transfer belt 3, a primary transfer roller 11a is disposed at a position facing the photoreceptor 1a with the intermediate transfer belt 3 interposed therebetween. The primary transfer roller 11 a contacts the inner peripheral surface of the intermediate transfer belt 3, so that an appropriate primary transfer nip is ensured between the photosensitive member 1 a and the intermediate transfer belt 3. The primary transfer roller 11a is applied with a primary transfer voltage having a polarity opposite to the toner charging polarity of the toner image formed on the photoreceptor 1a (plus polarity in the present embodiment). As a result, a primary transfer electric field is formed between the photosensitive member 1a and the intermediate transfer belt 3, and the toner image on the photosensitive member 1a is statically transferred onto the intermediate transfer belt 3 that is rotationally driven in synchronization with the photosensitive member 1a. Electrically primary transferred. Transfer residual toner adhering to the outer peripheral surface of the photoconductor 1a after the toner image is primarily transferred to the intermediate transfer belt 3 is removed by the cleaning device 12, and the outer peripheral surface of the photoconductor 1a is cleaned.

In the full color mode using all four color toner images, the magenta toner image, the cyan toner image, and the yellow for the other color photoconductors 1b, 1c, and 1d as well as the photoconductor 1a for the black toner image described above. Each toner image is formed. These color toner images are sequentially primary-transferred so as to be superimposed on the black toner image primarily transferred onto the intermediate transfer belt 3.
On the other hand, in the black monochromatic mode, the belt profile is changed by separating the primary transfer rollers 11b, 11c, and 11d from the photoreceptors 1b, 1c, and 1d by the contact / separation mechanism, so that magenta, cyan, The yellow photoreceptors 1b, 1c, and 1d are spaced apart. Only the black toner image is primarily transferred to the intermediate transfer belt 3 while only the black photosensitive member 1 a is in contact with the intermediate transfer belt 3.

  As shown in FIG. 1, a paper feeding device 14 is disposed at the lower part of the printer body. The paper feeding device 14 feeds the recording medium P made of transfer paper in the direction of arrow B in the figure by the rotation of the paper feeding roller 15. The recording medium P sent out is a portion of the intermediate transfer belt 3 wound around the drive roller 4 at a predetermined timing by a registration roller pair 16 and a secondary transfer roller which is an example of a transfer device arranged to face the portion. 17 is conveyed. At this time, a predetermined secondary transfer voltage is applied to the secondary transfer roller 17, whereby the toner image on the intermediate transfer belt 3 is secondarily transferred to the recording medium P.

  The recording medium P on which the toner image is secondarily transferred is further conveyed upward, and the toner image on the recording medium P is fixed by the action of heat and pressure of the fixing device 18. Then, the recording medium P that has passed through the fixing device 18 is discharged out of the image forming apparatus through a pair of paper discharge rollers 19 provided in the paper discharge unit.

Some toner remains as residual transfer toner on the intermediate transfer belt 3 after the toner image is transferred to the recording medium P. The residual transfer toner is removed from the intermediate transfer belt 3 by the belt cleaning device 20. In the belt cleaning device 20 according to the present embodiment, a blade-shaped cleaning blade 21 made of urethane or the like is used as a cleaning member, and the cleaning blade 21 is brought into contact with the surface of the intermediate transfer belt 3 in the counter direction. I am letting. As the belt cleaning device 20, various types can be used as appropriate. For example, the belt cleaning device 20 may be a capacitance type.
The transfer residual toner removed from the intermediate transfer belt 3 by the cleaning blade 21 is sent to the rear side in the longitudinal direction by a waste toner coil in a cleaning case (hereinafter referred to as “casing”), and is provided in the apparatus main body. The waste toner path is conveyed to a waste toner container.

  Further, the casing of the belt cleaning device 20 of the present embodiment is provided with an opening for bringing the cleaning blade 21 into contact with the intermediate transfer belt 3. Further, a portion of the casing facing the intermediate transfer belt 3 has a gap with respect to the surface of the intermediate transfer belt 3 in order to avoid contact with the intermediate transfer belt 3. For this reason, the transfer residual toner removed from the intermediate transfer belt 3 by the cleaning blade 21 may be scattered around the cleaning device through the gap between the intermediate transfer belt 3 and the casing. Therefore, in the belt cleaning device 20 of the present embodiment, side seals 22 as sealing members are arranged at both ends of the cleaning blade 21, and the gap between the casing and the intermediate transfer belt 3 is filled, so that the belt cleaning device 20 The toner is prevented from scattering.

FIG. 2 is an explanatory diagram of the side seal 22 provided in the belt cleaning device 20 provided in the printer.
As shown in FIG. 2, the side seal 22 is affixed to the case 20 a of the belt cleaning device 20 and closes the gap between the casing 20 a and the intermediate transfer belt 3. Further, the side seal 22 in the present embodiment includes a low sliding member 22a on the side in contact with the intermediate transfer belt 3, and a foam member 22b provided between the low sliding member 22a and the case 20a. It has a layer structure. The low sliding member 22a is made of Amvic GF0471, and the foaming member 22b is made of SM55 # 60.

Next, a belt control mechanism for controlling the movement of the intermediate transfer belt 3 in the axial direction of the tension roller 5 in this embodiment will be described.
FIG. 3 is an enlarged cross-sectional view of the shaft tilt mechanism 70 immediately after assembly.
FIG. 4 is an enlarged cross-sectional view of the shaft tilt mechanism 70 after the belt shift restriction.
The belt control mechanism of the intermediate transfer device 60 in the present embodiment is an axis inclination method, and the rotation shaft of the tension roller 5 which is one of a plurality of support rollers that stretch the intermediate transfer belt 3 is inclined. The intermediate transfer belt 3 includes a shaft tilt mechanism 70 that restricts the belt shift range within a predetermined restriction range.

As shown in FIG. 3, the tension roller 5 has a tension roller shaft 5 a that is coaxial with the rotation shaft of the tension roller 5. The tension roller shaft 5a has a cylindrical shape whose diameter is shorter than that of the tension roller 5. The tension roller shaft 5a is joined to the tension roller 5 and supported by a rotation support member 34 via a tension roller bearing member 33 described later.
The shaft tilt mechanism 70 includes a belt shift detection member 30, a shaft displacement member 31, a shaft guide portion 35, and a rotation support member 34 in order from the inner side in the axial direction along the tension roller shaft 5a. The tension roller shaft 5a passes through these members.

The belt deviation detecting member 30 is provided at the end of the tension roller 5 so as to be movable in the axial direction of the tension roller 5 (hereinafter referred to as “roller axial direction”). The intermediate transfer belt 3 is a belt abutting member that moves in the roller axis direction by abutting against a belt abutting portion 30 a that is a part of the belt deviation detecting member 30.
The shaft displacement member 31 is provided so as to be in contact with the belt shift detection member 30 on the inner side in the roller axial direction. When the end of the intermediate transfer belt 3 hits and the belt deviation detecting member 30 moves outward in the roller axial direction, the shaft displacement member 31 is pushed by the belt deviation detecting member 30 and moves outward in the roller axial direction. Further, the shaft displacement member 31 has an inclined surface 31a that is a flat surface that is inclined with the outer side in the roller axial direction down with respect to a surface parallel to the surface of the belt 3 on the outer side in the roller axis direction. Further, since the above-described tension roller shaft 5a penetrates the shaft displacement member 31, it moves along with the movement of the shaft displacement member 31 in the roller axis direction. Further, a shaft guide portion 35 is provided in contact with the inclined surface 31 a of the shaft displacement member 31.

The shaft guide portion 35 is provided on the frame 37 of the apparatus main body, and is in contact with the inclined surface 31 a of the shaft displacement member 31 at an inclined surface contact portion 35 a which is a part of the shaft guide portion 35. Further, even if the tension roller shaft 5a and the shaft displacement member 31 move, the shaft guide portion 35 is fixed so as not to move. With such a configuration, when the shaft displacement member 31 moves outward in the roller roller axial direction, the position of the inclined surface 31a with which the inclined surface contact portion 35a contacts is shifted upward as shown in FIG. The tension roller shaft 5a passing through the shaft displacement member 31 is inclined.
Further, the frame 37 is provided with a support member rotating shaft 36 that protrudes toward the outer side in the roller axial direction from the surface on the outer side in the roller axial direction of the frame 37.

FIG. 5A is a schematic diagram of the configuration of the shaft tilting mechanism 70 of the intermediate transfer belt 3 immediately after assembly when viewed from the axial direction of the tension roller 5. FIG. 5B is a schematic diagram of the configuration of the shaft tilting mechanism 70 after the belt shift restriction is viewed from the axial direction of the tension roller 5.
The support member rotation shaft 36 is a shaft member that supports the rotation support member 34 so as to be rotatable with respect to the frame 37 in the direction of the arrow in FIG. One end of a support member biasing spring 40 that applies a biasing force to the rotation support member 34 is fixed to the frame 37. The other end of the support member biasing spring 40 is fixed to the rotation support member 34.
The rotation support member 34 disposed at the end of the tension roller shaft 5a is urged by the support member urging spring 40 so as to rotate clockwise around the support member rotation shaft 36 in FIG. .

The rotation support member 34 supports a tension roller bearing member 33 that supports the tension roller shaft 5 a so as to be slidable in the radial direction from the rotation center of the rotation support member 34. The tension roller bearing member 33 is attached to the rotation support member 34 by the tension spring 32 from the rotation center of the rotation support member 34 toward the radially outer side (left side in FIG. 5) opposite to the drive roller 4. It is energized. As a result, the tension roller 5 always receives an urging force in a direction away from the drive roller 4, and applies a predetermined tension to the intermediate transfer belt 3 stretched around a plurality of support rollers including the drive roller 4 and the tension roller 5. can do.
Further, when the rotation support member 34 rotates about the support member rotation shaft 36, the end portion of the tension roller shaft 5a supported by the rotation support member 34 via the tension roller bearing member 33 is displaced in the vertical direction. To do.

Next, the operation of the shaft tilt mechanism 70 in the intermediate transfer device 60 of the present embodiment will be described.
When the driving roller 4 starts to rotate, the tension roller 5 that is a driven roller around which the intermediate transfer belt 3 is wound also starts to rotate. At this time, if the end of the intermediate transfer belt 3 or the vicinity of the end is in contact with the belt shift detection member 30, the belt shift detection member 30 also starts to rotate.

  In this state, if the intermediate transfer belt 3 is shifted toward the right side in FIG. 3 in the belt width direction due to the parallelism between the members, the right end portion in the width direction of the intermediate transfer belt 3 is the belt end. It contacts the belt contact portion 30a of the deviation detecting member 30. In response to this abutting force, the belt deviation detection member 30 moves along the tension roller shaft 5a to the outside in the roller axis direction (right side in FIG. 3). When the belt deviation detecting member 30 moves outward in the roller axis direction along the tension roller shaft 5a, the shaft displacement member 31 disposed further outside the tension roller shaft 5a with respect to the belt deviation detecting member 30 detects the belt deviation. The member 30 is pressed toward the outside in the roller axial direction. As a result, the shaft displacement member 31 also moves outward in the roller axis direction along the tension roller shaft 5a.

As shown in FIG. 3, the shaft displacing member 31 includes an inclined surface 31a that is inclined with respect to the tension roller shaft 5a. The inclined surface contact portion 35a of the shaft guide portion 35 is in contact with the inclined surface 31a from the outer side in the roller axis direction (right side in FIG. 3).
Further, the end portion of the tension roller shaft 5a on the outer side in the roller axis direction (right side in FIG. 3) with respect to the position where the shaft displacement member 31 is provided, via the tension roller bearing member 33 as described above. It is supported by the rotation support member 34. Since the rotation support member 34 is urged by the support member urging spring 40 so as to rotate in the clockwise direction in FIG. 5 about the support member rotation shaft 36, the end portion of the tension roller shaft 5a is shown in FIG. I am receiving an urging force toward the inside.

  The shaft displacement member 31 includes a stopper portion 31c that is continuous with the lower end of the inclined surface 31a and extends in a direction along the tension roller shaft 5a. In a state where the end portion in the width direction of the intermediate transfer belt 3 is not in contact with the belt deviation detecting member 30, the stopper portion 31c of the shaft displacement member 31 that is going to move upward is biased by the biasing force of the support member biasing spring 40. It strikes against the lower surface of the guide part 35. Therefore, the contact position between the inclined surface 31a of the shaft displacement member 31 and the inclined surface contact portion 35a of the shaft guide portion 35 at a position where the stopper portion 31c of the shaft displacement member 31 and the lower surface of the shaft guide portion 35 contact each other. Is regulated. Therefore, the positional relationship of each member is maintained in a state where the inclined surface contact portion 35a of the shaft guide portion 35 is in contact with the lower end portion of the inclined surface 31a of the shaft displacement member 31.

From this state, when the intermediate transfer belt 3 receives a force that moves to the right in FIG. 3 in the belt width direction as described above, the end in the width direction of the intermediate transfer belt 3 contacts the belt shift detection member 30. . Further, when the intermediate transfer belt 3 moves in the belt width direction, the belt deviation detection member 30 and the shaft displacement member 31 move along the tension roller shaft 5a to the outside in the roller axis direction (right side in FIG. 3). At this time, the inclined surface contact portion 35 a of the shaft guide portion 35 relatively moves along the inclined surface 31 a of the shaft displacement member 31. Thereby, the contact position of the inclined surface 31a of the shaft displacement member 31 and the inclined surface contact portion 35a of the shaft guide portion 35 tends to be displaced upward in the inclined surface 31a.
As a result, the end portion of the tension roller shaft 5a is pushed down against the upward biasing force of the support member biasing spring 40.

  Therefore, the end portion of the tension roller shaft 5a on the side in which the intermediate transfer belt 3 moves (the right side in FIG. 3) is pushed down with the other end as a fulcrum, and the tension roller shaft 5a is inclined, and FIG. It will be in the state shown in

In this way, as the tension roller shaft 5a is inclined, the moving speed of the intermediate transfer belt 3 in the belt width direction gradually decreases, and finally the intermediate transfer belt 3 moves in the opposite direction of the belt width direction. It becomes like this. As a result, the position in the width direction of the intermediate transfer belt 3 is gradually returned, and the intermediate transfer belt 3 can stably travel at the position in the width direction where the belt shift converges.
In addition, when the belt shift of the intermediate transfer belt 3 occurs in the reverse direction, for example, even when the belt shift occurs on the right side in FIG. 4 in the state of FIG. 4, each state is changed from the state of FIG. 4 to the state of FIG. By moving the member in the reverse direction as described above, it is possible to converge the belt.

Here, the principle that the belt of the intermediate transfer belt 3 can be returned by tilting the tension roller shaft 5a will be described.
Assuming that the intermediate transfer belt 3 is a rigid body, attention is paid to an arbitrary point on the intermediate transfer belt 3 before entering the tension roller 5 (here, a point E on the belt end). If the intermediate transfer belt 3 stretched around the plurality of support rollers is in a completely horizontal or parallel state, it rotates on the tension roller without moving in the axial direction of the tension roller as the tension roller 5 rotates. Become. For this reason, between the point E on the intermediate transfer belt 3 just before entering the tension roller 5 and the point E ′ corresponding to the point E on the intermediate transfer belt 3 just after leaving the tension roller 5, There is no deviation in the position of the tension roller 5 in the rotation axis direction. In this case, no belt shift occurs in the intermediate transfer belt 3.

On the other hand, when the tension roller shaft 5a is inclined with respect to the other support roller shaft, the point E on the intermediate transfer belt 3 moves along the peripheral surface of the tension roller 5 when the inclination angle is α. In the meantime, the tension roller 5 is displaced in the direction of the rotation axis by about tan α. That is, in FIG. 3, when the tension roller shaft 5a is tilted downward by an inclination angle α with respect to the drive roller 4 disposed on the upstream side when viewed in the direction of the intermediate transfer belt 3 entering the tension roller 5, the intermediate transfer The belt 3 can be moved to the left in the figure by tan α in accordance with the rotation of the tension roller 5.
Since this action is a physical action, when the tension roller shaft 5a is tilted upward from the horizontal direction, the intermediate transfer belt 3 is moved to the right in the drawing in accordance with the rotation of the tension roller 5. Is possible.

  Further, the shift amount of the intermediate transfer belt is proportional to the inclination angle α. That is, the greater the inclination angle α, the greater the amount of deviation of the intermediate transfer belt, and the smaller the angle, the smaller the amount of deviation of the belt. Therefore, for example, as shown in FIG. 3, when the intermediate transfer belt 3 is shifted toward the right side in FIG. 3, the shaft displacement member 31 moves in the direction of the rotation axis of the tension roller 5 due to this belt shift. Then, the tension roller shaft 5a is lowered to the lower side in the drawing, so that the belt can be shifted to return the intermediate transfer belt 3 to the left side in FIG. Then, the belt shift of the intermediate transfer belt 3 is adjusted to a position where the belt shift originally generated in the intermediate transfer belt 3 and the reverse belt shift of the intermediate transfer belt 3 generated by the inclination of the tension roller shaft 5a are balanced. It can be converged. Even if the intermediate transfer belt 3 running at this balance position further shifts to one of the belts, the tension roller shaft 5a is inclined in response to the belt shift, so that the intermediate transfer belt 3 again. The belt shift converges at another balanced position.

  As described above, according to the shaft tilting mechanism 70 of the intermediate transfer device 60 in this embodiment, the intermediate transfer belt 3a is tilted according to the amount of movement of the intermediate transfer belt 3 in the belt width direction to the tension roller shaft 5a. The belt shift of 3 can be converged early. In addition, the driving force for tilting the tension roller shaft 5a uses the force by which the intermediate transfer belt 3 moves in the belt width direction, and thus can be realized with a simple configuration that does not require a driving source such as a motor.

Next, the configuration of the shaft displacement member 31 will be described.
FIG. 6 is a perspective view of the shaft displacement member 31 in the present embodiment.
The shaft displacement member 31 of the present embodiment has a configuration in which a protruding portion having an inclined surface 31a on the outer peripheral surface of a cylindrical main body and a cylindrical stopper portion 31c that contacts the lower surface of the shaft guide portion 35 are formed. Yes. In addition, a contact portion 31b that contacts the end portion of the intermediate transfer belt 3 is formed in a cylindrical shape.

The inclined surface 31a is configured by a curved surface formed so as to form a part of a conical circumferential surface centering on the central axis of the cylindrical main body. There are two reasons why the inclined surface 31a is a curved surface. The first reason is to prevent the tilt angle of the tension roller 5 from changing even if the shaft displacement member 31 slightly rotates around the tension roller shaft 5a. The second reason is that the contact with the inclined surface abutting portion 35a of the shaft guide portion 35 is brought close to point contact, and friction at the contact point is reduced, so that the end portion of the intermediate transfer belt 3 and the belt deviation detecting member are detected. This is because the contact pressure with the belt 30 is reduced, the deterioration of the end of the intermediate transfer belt 3 is suppressed, and the life of the intermediate transfer belt 3 is extended. In this embodiment, the inclination angle β of the inclined surface 31a with respect to the tension roller shaft 5a is 30 °, and the material of the shaft displacement member 31 is POM (polyacetal), but is not limited thereto.
Further, the shaft displacement member 31 is fixed to the shaft displacement member 31 and is configured not to rotate around the tension roller shaft 5a by coming into contact with a rotation stop member protruding toward the inner side in the roller axial direction.

  Further, the inclined surface abutting portion 35a of the shaft guide portion 35 in the present embodiment is a linear corner portion extending in the front-back direction in FIG. 3, and this corner portion is a curved surface shape, here R It has a shape. Since the inclined surface abutting portion 35a has a linear corner portion, the shaft displacement member 31 can be used as a guide portion even if the circumference of the intermediate transfer belt 3 changes due to environmental changes or the like and the tension roller 5 moves in the belt traveling direction. Point contact can be maintained at the same height as 35.

  In the configuration in which the support roller is not tilted and is not controlled to be shifted, the belt shift detection member provided on the end surface of the tension roller 5 is directly pressed by the end surface of the intermediate transfer belt 3, and the stress is always applied. The end face of the intermediate transfer belt is the weakest part of the belt, and it was observed that the end of the belt occasionally breaks when actually observed. According to the shaft tilting mechanism 70 of this embodiment, the load on the belt end surface can be reduced by tilting the support roller, and the belt shift can be controlled.

An example of specific configurations of the tension roller 5 and the intermediate transfer belt 3 of the present embodiment is shown below.
Tension roller outer diameter: φ26.18
Tension roller material: Aluminum Intermediate transfer belt material: Polyamideimide Intermediate transfer belt Young's modulus: 3400 MPa
Folding resistance by intermediate transfer belt MIT weather resistance test: 500 times Intermediate transfer belt thickness: 80 μm
Intermediate transfer belt linear velocity: 256 mm / s
Belt tension: 1.3 N / cm
In addition, it is based on JIS-P8115 as a folding-resistant frequency measurement method by a MIT weather resistance test. As measurement conditions, a sample having a width of 15 mm was measured under the conditions of a load of 1 kgf, a bending angle of 135 degrees, and a bending speed of 175 times / minute.

Next, the positional relationship between the side seal 22 and the belt deviation detection member 30 in the roller axis direction will be described.
FIG. 8 is an explanatory diagram of the positional relationship between the side seals of the belt cleaning device and the belt deviation detection member 30 in the comparative example.
In the shaft tilt mechanism of the present embodiment, when the end of the intermediate transfer belt 3 moves from the state shown in FIG. 4 toward the inner side in the roller axis direction (left side in FIG. 4), the belt protrusion by the end of the intermediate transfer belt 3 occurs. The contact force against the contact portion 30a is weakened, and the end of the tension roller shaft 5a is pushed up by the upward biasing force of the support member biasing spring 40. Then, the contact position between the shaft displacement member 31 and the shaft guide portion 35 is displaced downward along the slope of the shaft displacement member 31, so that the shaft displacement member 31 hits the belt shift detection member 30 and detects the belt shift. The member 30 is moved toward the inner side in the roller axial direction.

At this time, depending on the amount of movement of the belt in the roller axis direction, as shown by a range B in FIG. 8, the end portion of the side seal 22 interferes with the belt shift detection member 30 and is removed from the belt by the cleaning member. The toner may leak out of the cleaning device.
Specifically, when the belt deviation detection member 30 moves inward in the roller axis direction, the distance from the end of the cleaning blade 21 in the roller axis direction to the belt contact portion 30a is X, and the width of the side seal 22 in the roller axis direction. Is Y. In this case, as shown in FIG. 8, when the relationship between X and Y is X <Y, the side seal 22 and the belt deviation detection member 30 interfere with each other. If the belt deviation detection member 30 and the side seal 22 interfere with each other, the side seal 22 may be deformed and toner may leak from the casing 20a.

FIG. 7 is an explanatory diagram of the positional relationship between the side seal 22 and the belt deviation detection member 30 in the present embodiment.
Therefore, in the intermediate transfer device 60 according to the present embodiment, the belt abutting detection member 30 and the side seal 22 are arranged such that the belt abutting portion 30a of the belt deviation detecting member 30 is closest to the end of the side seal 22 in the roller axial direction. Occasionally, the positional relationship was as follows. That is, the positional relationship is such that the belt abutting portion 30a of the belt deviation detecting member 30 does not contact the end portion. Specifically, as shown in FIG. 7, the relationship between X and Y is always set to satisfy X ≧ Y. As a result, even if the end of the intermediate transfer belt 3 moves inward in the roller axis direction, it is possible to achieve a positional relationship in which the belt abutting portion 30a of the belt deviation detecting member 30 and the side seal 22 do not interfere with each other. Become. Therefore, toner leakage due to interference between the belt deviation detection member 30 and the side seal 22 can be prevented.

  When the belt shift detection member 30 moves inward in the roller axis direction, the casing 20a and the belt shift detection member 30 may interfere with each other depending on the shapes of the belt shift detection member 30 and the casing 20a. In order to prevent this interference, for example, the gap provided between the surface of the intermediate transfer belt 3 and the casing 20a is larger than the length of the belt contact portion 30a of the belt deviation detecting member 30 in the radial direction of the tension roller shaft 5a. The structure which performs is considered. Further, a configuration in which the length in the radial direction of the belt deviation detection member 30 is shortened so as not to contact the casing 20a is also conceivable. Thereby, interference with the belt deviation | shift detection member 30 and the casing 20a can be prevented.

  Further, in the intermediate transfer device 60 of the present embodiment, when the belt abutting portion 30a comes closest to the end portion of the side seal 22 in the roller axial direction, it is not in contact with the end portion, that is, X and The inclination amount of the tension roller 5 is limited so that the relationship of Y always satisfies X ≧ Y. Thereby, the movement amount of the belt deviation detection member 30 when the end portion of the intermediate transfer belt 3 moves inward in the roller axis direction can be limited.

Specifically, when the end portion of the intermediate transfer belt 3 moves inward in the roller axis direction, the contact force of the end portion of the intermediate transfer belt 3 to the belt shift detection member 30 is weakened, and the tension roller is supported by the support member biasing spring 40. The axis is pushed up. Then, the contact position between the shaft displacement member 31 and the shaft guide portion 35 is displaced downward along the slope of the shaft displacement portion. As a result, the shaft displacement member 31 that has moved inward in the roller axial direction along the tension roller shaft 5a abuts on the belt displacement detection member 30, thereby moving the belt displacement detection member 30 inward in the roller axial direction.
At this time, by limiting the inclination amount of the tension roller 5, the displacement of the contact position between the shaft displacement member 31 and the shaft guide portion 35 along the slope of the shaft displacement portion can be within a predetermined range. For this reason, it is possible to limit the amount of movement of the belt deviation detection member 30 that is caused when the shaft displacement member 31 abuts toward the inner side in the roller axial direction. Therefore, the positional relationship can be such that the side seal 22 and the belt deviation detection member 30 do not interfere with each other.

Further, in the present embodiment, the following configuration is adopted in order to limit the amount of inclination of the tension roller 5. That is, when the tension roller 5 is inclined by a predetermined amount, the stopper portion 31c of the shaft displacement member 31 and the lower surface of the shaft guide portion 35 are brought into contact with each other. Specifically, when the tension roller 5 is inclined when the end portion of the intermediate transfer belt 3 moves toward the inner side in the roller axial direction, the stopper portion 31 c hits the lower surface of the shaft guide portion 35. As a result, the displacement of the contact position between the inclined surface 31a of the shaft displacement member 31 and the inclined surface contact portion 35a of the shaft guide portion 35 is restricted, so that the movement of the tension roller shaft 5a by the shaft displacement member 31 is restricted. The inclination amount of the tension roller 5 can be limited within a predetermined range.
In the present embodiment, the width of the side seal 22 in the roller axial direction is set to 6 [mm].

Next, the arrangement of the support member rotation shaft 36 in the intermediate transfer device 60 will be described.
In the intermediate transfer device 60 according to the present embodiment, the support member rotation shaft 36 of the rotation support member 34 included in the shaft tilt mechanism 70 is disposed at the following position. That is, as shown in FIG. 5A, among the intermediate transfer belt 3 wound around the tension roller 5, the belt surface on the upstream side in the belt conveyance direction with respect to the tension roller 5 and the downstream side with respect to the tension roller 5. A virtual bisector a that is a bisector of an angle formed by the side belt surface is assumed. The support member rotation shaft 36 that is the rotation shaft of the rotation support member is disposed in a range that is opposite to the contact portion between the shaft displacement member 31 and the shaft guide portion 35 with the virtual bisector a interposed therebetween. ing.

  By arranging in this way, a force acts on the shaft displacement member 31 so as to move toward the shaft guide portion 35, and the shaft displacement member 31 and the shaft guide portion 35 come into contact with each other to tilt the tension roller 5. it can. Further, the support member biasing spring 40 may be omitted if the support member rotating shaft 36 is positioned so that the shaft displacement member 31 and the shaft guide portion 35 are in contact with each other.

  In the above description, the shaft tilt mechanism 70 that corrects the belt shift in which the intermediate transfer belt 3 moves to one side in the width direction has been described. However, the belt member that corrects the belt shift by the configuration of the shaft tilt mechanism 70 of the present embodiment is as follows. The intermediate transfer belt 3 is not limited to this. For example, it is configured to correct the belt shift of the transfer conveyance belt of the secondary transfer apparatus including the transfer conveyance belt that conveys the recording medium including the transfer position at which the image is transferred to the recording medium such as transfer paper of the image forming apparatus. Is also applicable.

What was demonstrated above is an example, and there exists an effect peculiar for every following aspect.
(Aspect A)
A belt such as an intermediate transfer belt 3 that runs around a plurality of support rotating bodies such as a driving roller 4, a tension roller 5, a backup roller 6, and an entrance roller 7 and travels along with the rotation of the plurality of support rotating bodies; Provided on a rotating shaft such as a tension roller shaft 5a of a supporting rotating body such as a tension roller 5 which is one of the supporting rotating bodies, the end of the belt in the axial direction of the rotating shaft abuts and is movable in the axial direction A belt abutting member such as a belt deviation detecting member 30; a cleaning member such as a cleaning blade 21 disposed opposite to the one supporting rotating body to remove deposits on the surface of the belt; and the shaft of the cleaning member A belt device such as an intermediate transfer device 60 provided with a seal member such as a side seal 22 disposed at an end in the direction. When the belt abutting member comes closest to the end of the seal member in the axial direction, the belt abutting member is not in contact with the end of the belt abutting member. To do.

When the end portion of the belt moves inward in the axial direction of one supporting rotating body, the belt abutting portion also moves inward in the coaxial direction along with this movement. At this time, depending on the amount of movement of the belt in the roller axis direction, the end of the seal member and the belt abutting member may interfere with each other, and the toner removed from the belt by the cleaning member may leak out of the cleaning device. is there.
In this aspect, as described in the above embodiment, when the belt abutting member comes closest to the end of the seal member in the coaxial direction, the belt abutting member does not come into contact with the end. Even if the end of the belt moves inward in the coaxial direction, the belt abutting member and the seal member do not interfere with each other. Accordingly, toner leakage due to interference between the belt abutting member and the seal member can be prevented.

(Aspect B)
The belt device according to aspect A is characterized in that the one supporting rotating body such as the tension roller 5 tilts with respect to the other supporting rotating body such as the driving roller 4.
In this aspect, as described for the above-described embodiment, even if the configuration is such that one support rotating body is inclined to regulate the belt shift, the belt abutting member and the seal member do not interfere with each other. It becomes possible to do. Accordingly, toner leakage due to interference between the belt abutting member and the seal member can be prevented.

(Aspect C)
The belt device according to aspect B is characterized by comprising a stopper member such as a stopper portion 31c for limiting the amount of inclination of the one supporting rotating body such as the tension roller 5 or the like.

  In this aspect, as described in the above embodiment, the belt abutting member is moved when the end of the belt moves inward in the coaxial direction by limiting the amount of inclination of one supporting rotating body. The amount can be limited. Therefore, the positional relationship can be such that the belt abutting member and the seal member do not interfere with each other.

(Aspect D)
In the belt device according to any one of the aspects A to C, the belt device is provided at least at one end portion of the rotation shaft of the one supporting rotating body, and the end portion in the axial direction of the belt is moved by moving the belt in the axial direction. Abutting and moving in the axial direction together with the belt, and having a belt abutting member such as a belt abutting portion 30a, and a belt detecting member such as a belt shift detecting member 30 and the movement of the belt in the axial direction A shaft tilting member such as a shaft displacement member 31 that tilts the one supporting rotating body, and a guide member such as a shaft guide portion 35 that contacts a part of the shaft tilting member and regulates the moving direction of the shaft tilting member. And a support force applying member such as a support member biasing spring 40 that applies a force in a direction in which the shaft inclined member and the guide member are in contact with each other.

(Aspect E)
A belt that is stretched over a plurality of support rotators and travels with the rotation of the plurality of support rotators; and a recording medium is carried on an outer peripheral surface of the belt, and a visible image formed on the image carrier is obtained. In the transfer device for transferring to the recording medium, the belt device according to any one of aspects A to D is provided.
According to this, as described in the above embodiment, it is possible to realize a transfer device that can prevent toner leakage due to interference between the belt abutting member and the seal member.

(Aspect F)
A visible image transferred from the image bearing member is transferred over a plurality of supporting rotating members such as the driving roller 4, the tension roller 5, the backup roller 6, and the entrance roller 7 and travels with the rotation of the supporting rotating members. The intermediate transfer device such as the intermediate transfer device 60 including the intermediate transfer belt such as the intermediate transfer belt 3 for transferring to the transfer medium is characterized by having the configuration of the belt device according to any one of aspects A to D.
According to this, as described in the above embodiment, it is possible to realize an intermediate transfer device that can prevent toner leakage due to interference between the belt abutting member and the seal member.

(Aspect G)
In an image forming apparatus such as a printer 100 that includes a belt device that travels belts wound around a plurality of support rotating bodies along with the rotation of the plurality of support rotating bodies, the belt device may be an intermediate of any one of modes A to D. A belt device such as a transfer device 60 is used.
According to this, it is possible to realize an image forming apparatus capable of preventing toner leakage due to interference between the belt abutting member and the seal member.

DESCRIPTION OF SYMBOLS 1 Photoconductor 3 Intermediate transfer belt 4 Drive roller 5 Tension roller 5a Tension roller shaft 8 Charging device 9 Exposure device 10 Development device 11 Primary transfer roller 12 Cleaning device 14 Paper feed device 16 Registration roller pair 17 Secondary transfer roller 18 Fixing device 20 Belt cleaning device 20a Case 21 Cleaning blade 22 Side seal 22a Low sliding member 22b Foaming member 30 Belt offset detecting member 30a Belt abutting portion 31 Shaft displacement member 31a Inclined surface 31b Contact portion 31c Stopper portion 32 Tension spring 33 Tension roller bearing member 34 rotation support member 35 shaft guide portion 35a inclined surface contact portion 36 support member rotation shaft 37 frame 40 support member biasing spring 60 intermediate transfer device 70 shaft tilt mechanism 100 printer

JP 2014-10429 A

Claims (7)

  A belt that is stretched over a plurality of support rotators and travels with the rotation of the plurality of support rotators, and is provided on a rotation shaft of at least one support rotator among the plurality of support rotators. An end portion of the belt in the axial direction abuts, a belt abutting member that is movable in the axial direction, a cleaning member that is disposed opposite to the one support rotating body and removes deposits on the surface of the belt, and the cleaning member And a sealing member disposed at the axial end of the belt, when the belt abutting member is closest to the axial end of the sealing member, the belt abutting is applied to the end. A belt device characterized by a positional relationship in which members do not contact.   2. The belt device according to claim 1, wherein the one supporting rotating body tilts with respect to another supporting rotating body.   The belt device according to claim 2, further comprising a stopper member that limits an inclination amount of the one supporting rotating body.   The belt device according to any one of claims 1 to 3, wherein the belt device is provided at at least one end of a rotation shaft of the one supporting rotating body, and the end of the belt is abutted by the belt moving in the axial direction. A belt detecting member that moves in the axial direction together with the belt and has the belt abutting member, a shaft inclined member that tilts the one supporting rotating body as the belt moves in the axial direction, and the shaft A guide member that abuts a part of the inclined member and restricts the moving direction of the shaft inclined member; and a support force applying member that applies force in a direction in which the shaft inclined member and the guide member are in contact with each other. A belt device characterized.   A belt that is stretched over a plurality of support rotators and travels with the rotation of the plurality of support rotators; and a recording medium is carried on an outer peripheral surface of the belt, and a visible image formed on the image carrier is obtained. 5. A transfer device for transferring to the recording medium, comprising the belt device according to any one of claims 1 to 4.   In an intermediate transfer device including an intermediate transfer belt that is stretched over a plurality of support rotating bodies and travels with the rotation of the plurality of support rotating bodies, and transfers a visible image transferred from an image carrier to a transfer target. An intermediate transfer device comprising the configuration of the belt device according to claim 1.   The belt device according to any one of claims 1 to 4, wherein the belt device is an image forming apparatus including a belt device that travels belts that are stretched around a plurality of support rotators together with the rotation of the plurality of support rotators. An image forming apparatus using the apparatus.

Images