JP7013772B2 - Transfer device and image forming device - Google Patents

Description

The present invention relates to a transfer device and an image forming device.

In the conventional image forming apparatus, the technique described in Patent Document 1 below is known as a technique for adjusting the tension of the belt.

According to Japanese Patent Application Laid-Open No. 2016-153847 as Patent Document 1, when the printing operation is started, the belt outer tension roller (711) moves to widen the contact area with the belt (701) and increase the tension. Described is a technique for suppressing plastic deformation of a belt by moving the belt outer tension corolla (711) to narrow the contact area with the belt (701) when the operation is completed and the printing operation is completed.

JP-A-2016-153847 ("0019"-"0021", "0024"-"0030", "0035"-"00, FIG. 3, FIG. 5, FIG. 7)

It is a technical subject of the present invention to reduce the tension when the transport means is not used and as compared with the time when the transport means is not used, without using a dedicated means for reducing the tension.

In order to solve the technical problem, the transfer apparatus of the invention according to claim 1 is used.
A transfer means that is arranged facing the image holder and transfers an image of the surface of the image holder to a medium.
A transport means composed of an endless and elastic body arranged between the image holder and the transfer means and stretched on the transfer means to hold and transport the medium on the surface.
A rotating means that supports the transporting means and rotates the transporting means,
A first support that supports the transfer means, the rotation means, and the transfer means, and
A second support that movably supports the first support so that the transfer means moves in a direction that approaches or separates from the image holder.
At the first position where the transfer means is supported by the second support and the transfer means is close to the image holder, the transfer means is in contact with the transfer means to apply tension to the transfer means, and the transfer means is the image holder. At the second position separated from the above, the tension applying means for weakening the tension applied to the transporting means as compared with the case of the first position, and the tension applying means.
The first support that is movably supported between the first position and the second position about the axis of rotation, and the first support.
The tension applying means arranged at a position closer to the rotation axis of the first support than the outer peripheral edge of the rotation locus of the first support.
Equipped with
The second support was movably supported about the axis of rotation with respect to the frame supporting the second support.
It is characterized by that.

The invention according to claim 2 is the transfer apparatus according to claim 1.
The tension applying means, which is arranged inside the endless transport means,
It is characterized by being equipped with.

The invention according to claim 3 is the transfer apparatus according to claim 2.
The tension applying means, which is rotatably and immovably supported by the second support,
It is characterized by being equipped with.

The invention according to claim 4 is the transfer apparatus according to any one of claims 1 to 3 .
The tension applying means, which is separated from the transporting means at the second position,
It is characterized by being equipped with.

The invention according to claim 5 is the transfer apparatus according to any one of claims 1 to 4 .
It is characterized in that the axial end of the rotating means is formed in a narrowed shape.

In order to solve the technical problem, the image forming apparatus of the invention according to claim 6 is used.
Image holder and
The transfer device according to any one of claims 1 to 5 , which is arranged so as to face the image holder and transfers an image formed on the image holder.
It is characterized by being equipped with.

According to the inventions of claims 1 and 6 , the tension can be weakened when the transport means is not used and as compared with the time when the transport means is not used, without using the dedicated means for weakening the tension.
According to the inventions of claims 1 and 6, the tension applying means moves too much with respect to the conveying means when the first support moves, as compared with the case where the tension applying means is far from the rotation axis. , It is possible to reduce the large deviation of tension.
According to the inventions of claims 1 and 6, even when the second support is movable, the tension applying means moves relative to the conveying means when the second support moves. It is possible to reduce a large deviation in tension due to excessive tension.
According to the second aspect of the present invention, the dirt of the tension applying means can be reduced as compared with the case where the tension applying means is arranged outside the transporting means.
According to the third aspect of the present invention, the position of the tension applying means can be stabilized and the tension can be stabilized as compared with the configuration in which the tension applying means is movable.

According to the fourth aspect of the present invention, the plastic deformation of the transporting means can be further suppressed as compared with the case where the tension applying means is not separated from the transporting means.
According to the fifth aspect of the present invention, it is possible to suppress the deviation of the transport means as compared with the case where the shape is not constricted.

FIG. 1 is an explanatory diagram of an image forming apparatus according to a first embodiment of the present invention. FIG. 2 is an explanatory diagram of a main part of the transfer device of the first embodiment, and is an explanatory diagram of a state in which the inner unit is moved to the contact position and the outer unit is moved to the image forming position. FIG. 3 is an explanatory diagram of a main part of the transfer device of the first embodiment, and is an explanatory diagram of a state in which the inner unit is moved to a separated position. FIG. 4 is an explanatory diagram of a main part of the transfer device of the first embodiment, and is an explanatory diagram of a state in which the outer unit is moved to the removal position. FIG. 5 is a perspective view of a main part of the transfer device of the first embodiment. FIG. 6 is an explanatory diagram for preventing the transport member of the first embodiment from being biased.

Next, specific examples of embodiments of the present invention (hereinafter referred to as Examples) will be described with reference to the drawings, but the present invention is not limited to the following examples.
In order to facilitate the understanding of the following explanations, in the drawings, the front-back direction is the X-axis direction, the left-right direction is the Y-axis direction, and the up-down direction is the Z-axis direction. The directions indicated by Z and −Z or the indicated sides are referred to as anterior, posterior, right, left, upward, downward, or anterior, posterior, right, left, upper, and inferior, respectively.
In addition, in the figure, the one with "・" in "○" means the arrow from the back of the paper to the front, and the one with "×" in "○" is the front of the paper. It shall mean an arrow pointing from to the back.
In addition, in the explanation using the following drawings, the illustrations other than the members necessary for the explanation are omitted as appropriate for the sake of easy understanding.

FIG. 1 is an explanatory diagram of an image forming apparatus according to a first embodiment of the present invention.
In FIG. 1, the copying machine U as an example of the image forming apparatus of the first embodiment is an example of a recording unit, and has a printer unit U1 as an example of an image recording apparatus. An example of a reading unit, a scanner unit U2 as an example of an image reading device, is supported on the upper portion of the printer unit U1. An auto feeder U3 as an example of a document transporting device is supported on the upper portion of the scanner unit U2. The scanner unit U2 of the first embodiment supports a user interface U0 as an example of an input unit. The user interface U0 can be input by an operator to operate the copying machine U.

An original tray TG1 as an example of a medium storage container is arranged on the upper part of the auto feeder U3. A plurality of original Gis to be copied can be stacked and stored in the original tray TG1. Below the document tray TG1, a document ejection tray TG2 is formed as an example of a document ejection section. A document transport roll U3b is arranged between the document tray TG1 and the document output tray TG2 along the document transport path U3a.

A platen glass PG as an example of a transparent platen is arranged on the upper surface of the scanner unit U2. In the scanner unit U2 of the first embodiment, an optical system A for reading is arranged below the platen glass PG. The reading optical system A of the first embodiment is supported so as to be movable in the left-right direction along the lower surface of the platen glass PG. The reading optical system A is normally stopped at the initial position shown in FIG.
An image pickup device CCD as an example of an image pickup member is arranged on the left side of the reading optical system A. An image processing unit GS is electrically connected to the image pickup device CCD.
The image processing unit GS is electrically connected to the writing circuit DL of the printer unit U1. The writing circuit DL is electrically connected to an exposure device ROS as an example of a latent image forming device.

A photoconductor drum PR as an example of an image holder is arranged in the printer unit U1. A charging roll CR as an example of a charging member, a developing device G, a transfer unit TU as an example of a transfer device, and a drum cleaner CLp as an example of a cleaning device are arranged around the photoconductor drum PR.

Below the transfer unit TU, the paper feed trays TR1 to TR4 as an example of the medium storage container are arranged. The transport path SH1 extends from each of the paper feed trays TR1 to TR4. In the transport path SH1, a pickup roll Rp as an example of a medium take-out member, a handling roll Rs as an example of a handling member, a transport roll Ra as an example of a transport member, and a cash register roll Rr as an example of a delivery member are arranged. There is.
On the right side of the transfer unit TU, a fixing device F having a heating roll Fh and a pressure roll Fp is arranged. The fixing device F and the output tray TRh are connected by an discharge path SH2. The discharge path SH2 and the receipt roll Rr are connected by an inversion path SH3. A transport roll Rb and a discharge roll Rh that can rotate in the forward and reverse directions are arranged in the discharge path SH2.

(Explanation of image formation operation)
The plurality of original Gis housed in the original tray TG1 sequentially pass through the reading positions of the originals on the platen glass PG and are ejected to the paper ejection tray TG2 of the originals.
When the original is automatically conveyed and copied using the auto feeder U3, each original that sequentially passes through the reading position on the platen glass PG with the optical system A for reading stopped at the initial position. Exposing Gi.
When the operator manually places the original Gi on the platen glass PG for copying, the optical system A for reading moves in the left-right direction, and the original on the platen glass PG is scanned while being exposed.
The reflected light from the original Gi passes through the optical system A for reading and is collected on the image pickup device CCD. The image pickup device CCD converts the reflected light of the document focused on the image pickup surface into an electric signal.

The image processing unit GS converts the read signal input from the image pickup device CCD into a digital image signal and outputs it to the writing circuit DL of the printer unit U1. The writing circuit DL outputs a control signal corresponding to the input image writing signal to the exposure apparatus ROS.
The charging roll CR charges the surface of the photoconductor drum PR in the charging region Q0. The exposure apparatus ROS outputs the laser beam L to form a latent image on the surface of the photoconductor drum PR in the latent image forming region Q1. The latent image on the surface of the photoconductor drum PR is developed into a visible image by the developing apparatus G in the developing region Q2. The transfer roll TR of the transfer unit TU transfers the visible image of the surface of the photoconductor drum PR to the recording sheet S as an example of the medium conveyed through the transfer path SH1 in the transfer region Q3. The transfer transfer belt TB of the transfer unit TU transfers the recording sheet S to the fixing device F. The fixing device F fixes the visible image transferred to the recording sheet S. The recording sheet S that has passed through the fixing device F is conveyed to the reversing path SH3 when double-sided printing is performed, and is discharged by the discharge roll Rh when it is discharged to the output tray TRh.

(Explanation of transfer device)
FIG. 2 is an explanatory diagram of a main part of the transfer device of the first embodiment, and is an explanatory diagram of a state in which the inner unit is moved to the contact position and the outer unit is moved to the image forming position.
FIG. 3 is an explanatory diagram of a main part of the transfer device of the first embodiment, and is an explanatory diagram of a state in which the inner unit is moved to a separated position.
FIG. 4 is an explanatory diagram of a main part of the transfer device of the first embodiment, and is an explanatory diagram of a state in which the outer unit is moved to the removal position.
FIG. 5 is a perspective view of a main part of the transfer device of the first embodiment.

In FIGS. 2 to 5, the transfer unit TU as an example of the transfer device of the first embodiment has a transfer roll TR as an example of the transfer means. Both ends of the transfer roll TR in the axial direction (front-back direction) are supported by the inner unit frame 1 as an example of the first support. The inner unit frame 1 is formed in a plate shape extending in the left-right direction, and is arranged so as to face each other in a pair of front and rear. The inner unit frame 1 supports a motor unit 2 as an example of a drive source. The motor unit 2 rotates and drives the transfer roll TR.

A first driven roll 6 as an example of a rotating member is rotatably supported on the inner unit frame 1 at a position on the downstream side of the transfer roll TR with respect to the sheet transport direction.
Further, in the inner unit frame 1, a second driven roll 7 as an example of the rotating means is rotatably supported on the downstream side of the first driven roll 6. In FIG. 5, in the second driven roll 7 of the first embodiment, narrowed portions 7a as an example of the offset prevention portion are formed at both ends in the axial direction.

FIG. 6 is an explanatory diagram for preventing the transport member of the first embodiment from being biased.
Here, the transfer transfer belt TB of the first embodiment is composed of a rubber belt as an example of an elastic material. In FIG. 6, when tension acts on the transfer transfer belt TB as an example of the transport means, the narrowed portion 7a is pressed so that both end portions are wound around the narrowed portion 7a. Therefore, a force 7b having an axially inward component acts on both ends of the transfer transfer belt TB. Therefore, the transfer transfer belt TB of the first embodiment is less likely to be biased to one side in the axial direction.
The rotation shaft 8 of the second driven roll 7 extends outward in the axial direction and is rotatably supported by a frame body (not shown) of the copying machine U.

In FIGS. 2 to 5, a spring accommodating box 11 as an example of the first actuated portion is arranged on the inner unit frame 1 on the opposite side of the rotating shaft 8. The spring accommodating box 11 is supported by the inner unit frame 1 so as to be movable in the vertical direction, that is, in the direction in which the transfer roll TR approaches and separates from the photoconductor drum PR. The spring accommodating box 11 accommodates a coil spring 12 as an example of the urging means. The coil spring 12 exerts an elastic force that pushes the inner unit frame 1 upward, and exerts a transfer pressure in the transfer region Q3 in which the transfer roll TR contacts the photoconductor drum PR. The spring accommodating box 11 and the coil spring 12 are arranged in pairs in the front-rear direction.

The inner unit 13 of the first embodiment is composed of the transfer roll TR, the transfer transfer belt TB, and the members designated by the reference numerals 1 to 12. The inner unit 13 of the first embodiment is centered on the rotation shaft 8 between a contact position as an example of the first position shown in FIG. 2 and a separation position as an example of the second position shown in FIG. It is supported to be movable.

Below the spring accommodating box 11, a first cam 21 as an example of the first actuating means is arranged. The first cam 21 is arranged in contact with the lower surface of the spring accommodating box 11.
The rotation shaft 21a of the first cam 21 is rotatably supported by the outer unit frame 22 as an example of the second support. A pair of outer unit frames 22 are arranged on the outer side in the front-rear direction with respect to the inner unit frame 1. Further, the outer unit frame 22 is formed in a plate shape extending in the left-right direction.

In FIG. 5, the outer unit frame 22 of the first embodiment is rotatably supported with respect to the rotation shaft 8. Therefore, the outer unit frame 22 of the first embodiment is also rotatably supported with respect to a frame (not shown) of the copying machine U about the rotation shaft 8.
The outer unit frame 22 of the first embodiment is formed with an abutting protrusion 22a as an example of a positioning portion at the upper left end portion. In FIGS. 2 to 4, the abutting protrusion 22a contacts the drum frame 23 as an example of the frame body that supports the photoconductor drum PR to position the outer unit frame 22. Therefore, when the outer unit frame 22 is positioned, the transfer roll TR supported via the first cam 21 and the inner unit frame 1 is positioned with respect to the photoconductor drum PR.

In FIGS. 2 to 4, the rear outer unit frame 22 supports a drive system 24 that controls the rotation of the first cam 21. The drive system 24 includes a motor 24a and a plurality of gears 24b and 24c as an example of a drive source. The motor 24a of the first embodiment operates in response to a control signal from the control unit C. In the first embodiment, when the image forming operation is started, the motor 24a rotates the first cam 21 to move it to the contact position shown in FIG. 2, and when the image forming operation is completed, the first cam 21 is rotated. It is configured to move to the separation position shown in FIG.

In FIGS. 2 to 5, a tension roll 26 as an example of tension applying means is supported between the outer unit frames 22. The tension roll 26 of the first embodiment is rotatably and immovably supported with respect to the outer unit frame 22. Further, the tension roll 26 is arranged inside the transfer transfer belt TB. Further, the tension roll 26 of the first embodiment is set at a position shown in FIG. 2 at a position where it contacts the inner surface of the transfer transfer belt TB and applies tension to the transfer transfer belt TB. Further, at the position shown in FIG. 3, the tension roll 26 is separated from the transfer transfer belt TB, and the tension of the transfer transfer belt TB is set to be weaker than that in the case of FIG.

The belt cleaner CLb as an example of a cleaning device for cleaning the transfer transfer belt TB is supported by the outer unit frame 22, but is not shown in FIG.
The outer unit 27 of the first embodiment is configured by the members designated by the reference numerals 22 to 26. As described above, the outer unit 27 is movably supported between the image forming position shown in FIG. 2 and the removal position shown in FIG. 4 around the rotation axis 8.

In FIGS. 2 to 4, a second cam 31 as an example of the second operating member is arranged below the outer unit frame 22. The second cam 31 is arranged in contact with the lower surface of the outer unit frame 22. The rotation shaft 31a of the second cam 31 is connected to a handle 32 as an example of the operating member. Therefore, the second cam 31 is configured to rotate when the operator operates the handle 32.

(Action of Example 1)
In the copying machine U of the first embodiment having the above configuration, when the image forming operation is started, the first cam 21 operates and the inner unit 13 moves to the contact position shown in FIG. Therefore, the transfer roll TR and the photoconductor drum PR face each other and come into contact with each other with the transfer transfer belt TB interposed therebetween. Then, at this time, the tension roll 26 presses against the transfer transfer belt TB and exerts a predetermined tension. Therefore, image formation is executed in this state.

When the image forming operation is completed, the first cam 21 operates and the inner unit 13 moves to the separated position shown in FIG. Therefore, the transfer roll TR is separated from the photoconductor drum PR. At this time, the tension applied to the transfer transfer belt TB by the tension roll 26 decreases.
Therefore, in the first embodiment, the tension is increased / decreased by using a configuration in which the transfer transfer belt TB and the transfer roll TR are separated from the photoconductor drum PR without using a dedicated component for increasing / decreasing the tension of the transfer transfer belt TB. Is possible. Therefore, it is possible to weaken the tension when the transfer transfer belt TB is not used, as compared with when it is used, without using a dedicated member or means for weakening the tension.

In the configuration using the transfer transfer belt TB, there is a limit in improving the accuracy of the parallelism of the transfer roll TR and the driven rolls 6 and 7 in order to prevent the transfer transfer belt TB from shifting and meandering. Therefore, a mechanism for preventing the belt from shifting is required. However, when an elastic belt having elasticity as in Example 1 is used, the tension should be increased to some extent as shown in FIG. Therefore, it is possible to control the deviation of the transfer transfer belt TB. However, a high tension is required so that the transfer transfer belt TB winds around the narrowed portion 7a. If this high tension is continuously applied, the transfer transfer belt TB may be plastically deformed over time. When plastically deformed, the tension decreases, and there is a risk of bias and meandering. Further, if high tension is continuously applied, cracks and cracks may occur in the transfer transfer belt TB. If cracks or the like occur, cleaning failure with the belt cleaner CLb may occur and the recording sheet S may be soiled.

Even if the transfer transport belt TB has a different configuration for preventing meandering, there is no change in the fact that plastic deformation occurs by continuing to apply tension.
Further, the transfer transfer belt TB is in contact with the photoconductor drum PR at a preset transfer pressure in the transfer region Q3. If the transfer belt TB continues to be in contact with the photoconductor drum PR even if only the tension of the transfer transfer belt TB is weakened, the portion sandwiched between the transfer roll TR and the photoconductor drum PR is plastically deformed and the transfer transfer belt TB There is a risk of getting a habit. If the transfer transfer belt TB becomes habitual, there is a risk that periodic speed fluctuations will occur in the rotation of the transfer transfer belt TB.

In the configuration described in Patent Document 1, a dedicated mechanism for increasing or decreasing the tension of the belt is described, and the configuration is separate from the configuration in which the belt is tentatively separated from the photoconductor or the like. Therefore, there is a problem that the number of parts increases and the configuration becomes complicated.
On the other hand, in the first embodiment, the transfer transfer belt TB can be brought into contact with and separated from the photoconductor drum PR and the tension can be increased or decreased only by moving the inner unit 13. Therefore, it is possible to suppress the plastic deformation of the transfer transfer belt TB with a simple structure. Therefore, the deviation of the transfer transfer belt TB and the occurrence of poor cleaning are also reduced.

Further, in the first embodiment, when the image forming operation is completed, the image forming operation is moved to the separation position shown in FIG. 3, and the photoconductor drum PR and the transfer transfer belt TB are separated from each other. At the separation position shown in FIG. 3, it is possible to make the contact pressure weaker without completely separating the photoconductor drum PR and the transfer transfer belt TB, but the first embodiment is more completely separated. , The plastic deformation of the transfer transfer belt TB can be further suppressed, and the life of the transfer transfer belt TB can be extended. Further, in the completely separated state, when the image forming operation is completed due to a paper jam or the like, the jammed paper can be easily taken out.
Further, in the transfer unit TU of the first embodiment, when the handle 32 is operated, both the inner unit 13 and the outer unit 27 are separated from the photoconductor drum PR as shown in FIG. Therefore, it is easy to replace the transfer unit TU or the unit on the photoconductor drum PR side. It is also possible to clear a paper jam.

Further, unlike the belt outer tension roller of Patent Document 1, the tension roll 26 of Example 1 is in contact with the inside of the transfer transfer belt TB. The outer surface of the transfer transfer belt TB may be contaminated with a developer, paper dust, or the like. When the tension roll 26 comes into contact with the outer surface of the transfer transfer belt TB, the tension roll 26 becomes dirty over time. When the tension roll 26 becomes dirty, the stain on the tension roll 26 may be re-transferred to the transfer transfer belt TB, and the transfer transfer belt TB may become dirty, which may stain the recording sheet S and the photoconductor drum PR. On the other hand, in the first embodiment, the tension roll 26 is in contact with the inside of the transfer transfer belt TB, and the tension roll 26 is not easily soiled.

Further, the tension roll 26 of the first embodiment is immovably supported by the outer unit frame 22. Therefore, the position of the tension roll 26 is more likely to be stable than when the tension roll 26 is supported so as to be movable up, down, left and right, or is pushed so as to apply tension by a spring. Therefore, the tension of the transfer transfer belt TB can be reliably increased or decreased. Also, the configuration is simplified compared to the movable configuration.

Further, in the transfer unit TU of the first embodiment, the tension roll 26 is arranged at a position closer to the rotation axis 8 than the first driven roll 6 and the transfer roll TR on the outer peripheral edge of the rotation locus. If the position of the tension roll 26 is far from the rotation shaft 8, the radius is large even if the rotation angle around the rotation shaft 8 is small, so that the relative movement distance of the tension roll 26 with respect to the transfer transfer belt TB is large. become longer. In this state, if the transfer transfer belt TB is in contact with or separated from the photoconductor drum PR due to rattling or the like, the position shift of the tension roll 26 with respect to the transfer transfer belt TB becomes large. Therefore, the deviation of the applied tension becomes large. On the other hand, in the first embodiment, the tension roll 26 is arranged at a position close to the rotation shaft 8, and the increase / decrease in tension does not become too large, and the tension can be increased / decreased with high sensitivity.
Further, in the transfer unit TU of the first embodiment, the outer unit 27 is also movably supported by using the rotation shaft 8 common to the inner unit 13. Therefore, even if a deviation occurs when the outer unit 27 is moved, it is possible to prevent the tension applied by the tension roll 26 from being excessively increased or decreased.

(Change example)
Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above embodiments, and various modifications are made within the scope of the gist of the present invention described in the claims. Is possible. Examples of modifications (H01) to (H08) of the present invention are illustrated below.
(H01) In each of the above embodiments, the copying machine U as an example of the image forming apparatus has been exemplified, but the present invention is not limited to this, and the present invention can be applied to a printer, a fax machine, or a multifunction device having a plurality of these functions. .. Further, the present invention is not limited to the image forming apparatus for monochromatic development, and can be configured by a multicolor, so-called color image forming apparatus.

(H02) In the above embodiment, the tension roll 26 is preferably arranged inside the transfer transfer belt TB, but it can also be configured to be in contact with the outer surface of the transfer transfer belt TB. At this time, it is desirable to provide a cleaning device for cleaning the tension roll 26.
(H03) In the above embodiment, it is desirable, but not limited to, the tension roll 26 to be immovable to the outer unit frame 22. It is also possible to support the transfer transfer belt TB so as to be movable in a direction in which tension is applied, and to apply tension to the transfer transfer belt TB by a spring or the like.

(H04) In the above embodiment, the configuration in which the inner unit 13 and the outer unit 27 can rotate about the rotation shaft 8 is exemplified, but the present invention is not limited thereto. For example, instead of the rotating configuration, it is possible to configure the configuration so that it can move up and down in the vertical direction. Further, it is desirable to reduce the number of parts by sharing the rotation shaft 8 of the inner unit 13 and the outer unit 27, but it is also possible to provide the rotation shaft separately.
(H05) In the above embodiment, it is desirable that the tension roll 26 is arranged at a position close to the rotation shaft 8, but it is also possible to arrange the tension roll 26 at a position away from the rotating shaft 8.

(H06) In the above embodiment, it is desirable that the transfer transfer belt TB and the photoconductor drum PR are completely separated from each other at the separated position, but they are not completely separated and are in contact with each other in a weak contact pressure. It is also possible to. Further, the relationship between the transfer transfer belt TB and the tension roll 26 is the same, and the structure may be such that they are completely separated from each other, or they may be in contact with each other in a state where the tension is weak.
(H07) In the above embodiment, it is desirable that the outer unit 27 is rotatable about the rotation shaft 8, but the outer unit 27 may be non-movable.

(H08) In the above embodiment, the transfer transfer belt TB is exemplified as the transfer member, but the transfer member is not limited to this. It can be applied to any transport belt that holds and transports the medium.

1 ... First support,
6, 7 ... Rotating means,
8 ... Rotation axis,
22 ... Second support,
26 ... Tension applying means,
PR ... Image holder,
S ... medium,
TB ... Transport means,
TR ... Transfer means,
TU ... Transfer device,
U ... Image forming apparatus.

Claims (6)

A transfer means that is arranged facing the image holder and transfers an image of the surface of the image holder to a medium.
A transport means composed of an endless and elastic body arranged between the image holder and the transfer means and stretched on the transfer means to hold and transport the medium on the surface.
A rotating means that supports the transporting means and rotates the transporting means,
A first support that supports the transfer means, the rotation means, and the transfer means, and
A second support that movably supports the first support so that the transfer means moves in a direction that approaches or separates from the image holder.
At the first position where the transfer means is supported by the second support and the transfer means is close to the image holder, the transfer means is in contact with the transfer means to apply tension to the transfer means, and the transfer means is the image holder. At the second position separated from the above, the tension applying means for weakening the tension applied to the transporting means as compared with the case of the first position, and the tension applying means.
The first support that is movably supported between the first position and the second position about the axis of rotation, and the first support.
The tension applying means arranged at a position closer to the rotation axis of the first support than the outer peripheral edge of the rotation locus of the first support.
Equipped with
The second support was movably supported about the axis of rotation with respect to the frame supporting the second support.
A transfer device characterized by that. The tension applying means, which is arranged inside the endless transport means,
The transfer apparatus according to claim 1, wherein the transfer apparatus is provided with. The tension applying means, which is rotatably and immovably supported by the second support,
2. The transfer device according to claim 2, wherein the transfer device is provided with. The tension applying means, which is separated from the transporting means at the second position,
The transfer apparatus according to any one of claims 1 to 3 , wherein the transfer apparatus is provided with. The transfer device according to any one of claims 1 to 4 , wherein the axial end of the rotating means is formed in a narrowed shape. Image holder and
The transfer device according to any one of claims 1 to 5 , which is arranged so as to face the image holder and transfers an image formed on the image holder.
An image forming apparatus characterized by being equipped with.

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