JP2010249903A - Transfer device and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To more reliably suppress banding in a transfer section even when a recessed portion is formed in a transfer roller. <P>SOLUTION: A transfer device 13 includes: the secondary transfer roller 14 that includes a recessed portion 17 and forms a secondary transfer nip 13a in firm contact with an intermediate transfer belt 8 carrying an image; a biasing means (48) that brings the secondary transfer roller 14 into firm contact with the intermediate transfer belt 8; and a transfer roller position restricting part 47b that restricts the movement of the transfer roller 14 by the biasing means when the recessed portion 17 is brought opposite the position where the transfer nip 13a is formed. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an electrophotographic transfer apparatus and an image forming apparatus that transfer an image on an image carrier onto a transfer material such as paper using a transfer roller that is pressed against an image carrier that carries the image to be transferred.

  In a wet image forming apparatus using a liquid developer, the transfer surface of the transfer material on the toner image side is pressed against the image carrier, so that the transfer material tends to stick to the image carrier after transfer. Therefore, conventionally, an image forming apparatus has been proposed in which air is blown to the front end of a transfer material after transfer to peel the transfer material from the image carrier (see, for example, Patent Document 1). In Patent Document 1, the transfer roller corresponds to the image carrier referred to in the present invention, and the fixing roller corresponds to the transfer roller referred to in the present invention.

  On the other hand, in an image forming apparatus using a dry developer, the transfer material (corresponding to the transfer roller of the present invention) that is pressed against the photoconductor as an image carrier is gripped with the tip of the transfer material gripped. An image forming apparatus for transferring a toner image on a body to a transfer material has been proposed (see, for example, Patent Document 2). By performing transfer with the tip of the transfer material gripped, the transfer material can be peeled off from the photoreceptor after transfer.

  Further, in the stencil printing apparatus, there has been proposed a stencil printing apparatus that performs stencil printing of an ink image of a plate cylinder on a transfer material in a state in which a leading end of the transfer material is clamped by a clamper of a pressure cylinder pressed against the plate cylinder (for example, And Patent Document 3). In this way, printing is performed in a state where the leading end portion of the transfer material is clamped, whereby the transfer material can be peeled off from the plate cylinder after printing.

Japanese Patent No. 3128067. JP-A-3-4241. JP 2000-238400 A.

  However, in the image forming apparatus described in Patent Document 1 described above, since air is simply blown to the front end portion of the transfer material, it is difficult to reliably peel off the transfer material from the image carrier. In view of this, it is conceivable to apply to the image forming apparatus a technique for peeling off the front end of the transfer material using a grip described in Patent Document 2 or a clamp described in Patent Document 3. However, each of the transfer material gripping members such as the gripper described in Patent Document 2 or the clamper described in Patent Document 3 can be applied from the outer peripheral surface of the transfer drum or the outer peripheral surface of the impression cylinder in a state where the leading end portion of the transfer material is gripped. Protruding. For this reason, when the transfer material gripping member comes to the nip portion between the photoconductor and the transfer drum (the contact portion between them) or the nip portion between the plate cylinder and the impression cylinder (the contact portion between them) during transfer, the photoconductor and the transfer drum. Or the relative position between the plate cylinder and the impression cylinder greatly varies. Therefore, as described in Patent Document 3, it is conceivable to provide the transfer drum with a recess for housing the transfer material gripping member so that the transfer material gripping member that grips the transfer material does not protrude from the recess. However, if a recess is provided in the transfer drum, banding occurs in the transfer portion due to the contact of the recess with the photoreceptor. In addition, even in an image forming apparatus that performs primary transfer and secondary transfer having an intermediate transfer medium such as an intermediate transfer belt, this banding is achieved by providing a recess on the transfer drum for secondary transfer. It happens in both.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide an electrophotographic transfer device that can more reliably suppress banding in the transfer portion even when a recess is formed in the transfer roller. And an image forming apparatus.

  In order to solve the above-described problems, in the transfer device and the image forming apparatus according to the present invention, the transfer roller having the concave portion is always urged toward the image carrier by the press contact member. When the concave portion of the transfer roller does not face the transfer nip position, the movement of the transfer roller is not restricted by the restricting portion. Further, when the concave portion of the transfer roller faces the transfer nip position, the movement of the transfer roller is restricted by the restricting portion. Therefore, when the concave portion of the transfer roller faces the transfer nip position, the position (movement) of the transfer roller can be reliably restricted by the restricting portion. Thereby, when the concave portion of the transfer roller faces the transfer nip position, it is possible to prevent the transfer roller from greatly changing so that the transfer roller does not approach the image carrier.

  Then, by suppressing the relative position change between the transfer roller and the image carrier, the contact between the transfer roller and the image carrier is reliably avoided when the concave portion faces the transfer nip position, thereby suppressing the banding in the transfer. be able to. As a result, the image can be stably transferred to the transfer material, and a good image can be formed.

  In particular, since the image carrier and the transfer roller are integrally supported by the support frame, the relative positions of the image carrier and the transfer roller are more accurately positioned. Therefore, the holding of the transfer material can be stabilized and the transfer nip can be formed stably. This makes it possible to transfer the toner image onto the transfer material even more stably.

  Further, in the image forming apparatus having the first transfer portion and the second transfer portion, since banding in the second transfer portion can be suppressed, banding in transfer in the first transfer portion can also be suppressed. .

  Further, by supporting the image carrier, the transfer roller, and the gate roller integrally with the support frame, the relative positions of the image carrier, the transfer roller, and the gate roller are more accurately positioned. Accordingly, the transfer material can be stably conveyed to the transfer nip, and the transfer material can be more stably held by the stable conveyance of the transfer material. This makes it possible to transfer the toner image onto the transfer material even more stably. In that case, the transfer material supply guide is also integrally supported by the support frame, so that the transfer of the transfer material to the transfer nip can be further stabilized.

  Furthermore, the relative positions of the image carrier, the transfer roller, and the transfer material guide are more accurately positioned by integrally supporting the image carrier, the transfer roller, and the transfer material guide by the support frame. Therefore, the transfer of the transfer material after transfer can be stabilized. This makes it possible to reliably transfer the transferred transfer material to the next processing unit such as a fixing unit.

  In addition, by supporting the image carrier, transfer roller, gate roller, and transfer material guide unit together with the support frame, the relative positions of the image carrier, transfer roller, gate roller, and projection material guide unit are more accurate. Is positioned. Therefore, the conveyance of the transfer material before transfer and the conveyance of the transfer material after transfer can be stabilized. Accordingly, the transfer material before transfer can be reliably conveyed by the transfer nip, and the transfer material after transfer can be reliably conveyed to a next processing unit such as a fixing unit.

FIG. 6 is a diagram schematically and partially showing a first example to a fifth example of an embodiment of an image forming apparatus according to the present invention. FIG. 3 is a partial view schematically showing a secondary transfer portion of the image forming apparatus of the first example of the embodiment of the image forming apparatus according to the present invention. (A), (b) is sectional drawing which follows the III-III line in FIG. FIG. 3 is a view similar to FIG. 2, schematically and partially showing a second example of the embodiment of the image forming apparatus according to the present invention. (A), (b) is sectional drawing similar to Fig.3 (a), (b) along the VV line in FIG. FIG. 6 is a view similar to FIG. 2, schematically and partially showing a third example of the embodiment of the image forming apparatus according to the present invention. (A), (b) is sectional drawing similar to FIG. 3 (a), (b) which follows the VII-VII line in FIG. FIG. 6 is a view similar to FIG. 2 schematically and partially showing a fourth example of the embodiment of the image forming apparatus according to the present invention. (A), (b) is sectional drawing similar to FIG. 3 (a), (b) which follows the IX-IX line in FIG. FIG. 10 is a view similar to FIG. 2, schematically and partially showing a fifth example of an embodiment of an image forming apparatus according to the present invention. (A), (b) is sectional drawing similar to FIG. 3 (a), (b) which follows the XI-XI line in FIG.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.
FIG. 1 is a diagram schematically and partially showing a part of first to fifth examples of an embodiment of an image forming apparatus provided with a transfer device according to the present invention.
First, a configuration common to the image forming apparatuses 1 of the first to fifth examples will be described. As shown in FIG. 1, the image forming apparatuses 1 of the first to fifth examples perform image formation using a liquid developer containing solid toner and carrier liquid. As shown in FIG. 1, an image forming apparatus 1 includes a photoconductor that is an image carrier of yellow (Y), magenta (M), cyan (C), and black (K) arranged in tandem horizontally or substantially horizontally. 2Y, 2M, 2C, 2K. here,
In each of the photoconductors 2Y, 2M, 2C, and 2K, 2Y represents a yellow photoconductor, 2M represents a magenta photoconductor, 2C represents a cyan photoconductor, and 2K represents a black photoconductor. Similarly, the members of the respective colors are represented by adding Y, M, C, and K of the respective colors to the reference numerals of the members.

Charging units 3Y, 3M, 3C, and 3K are provided around the photoreceptors 2Y, 2M, 2C, and 2K, respectively. Further, from each of the charging units 3Y, 3M, 3C, and 3K, the exposure units 4Y, 4M, 4C, and 4K, and the developing unit are sequentially arranged in the rotation directions indicated by the arrows of the photosensitive members 2Y, 2M, 2C, and 2K, respectively. 5Y, 5M, 5C, and 5K, primary transfer portions 6Y, 6M, 6C, and 6K that are the first image carrier of the present invention, and photosensitive member cleaning portions 7Y, 7M, 7C, and 7K are disposed.

Further, the image forming apparatus 1 includes an endless intermediate transfer belt 8 (corresponding to an image carrier) that is a transfer belt. The intermediate transfer belt 8 is disposed above the photoreceptors 2Y, 2M, 2C, and 2K. The intermediate transfer belt 8 is pressed against the photoreceptors 2Y, 2M, 2C, and 2K at the primary transfer portions 6Y, 6M, 6C, and 6K.

Although not shown, the intermediate transfer belt 8 includes a flexible base material such as a resin, an elastic layer such as rubber formed on the surface of the base material, and a surface layer formed on the surface of the elastic layer. It is formed in a relatively soft elastic belt having a three-layer structure. Of course, it is not limited to this. The intermediate transfer belt 8 is wound around an intermediate transfer belt driving roller 9 to which a driving force of a motor (not shown) is transmitted, and an intermediate transfer belt tension roller 11. The intermediate transfer belt 8 is rotated in the direction of the arrow in a state where a tension is applied.
Note that the arrangement order of members such as photoconductors corresponding to the respective colors Y, M, C, and K is not limited to the example shown in FIG. 1 and can be arbitrarily set.

On the intermediate transfer belt drive roller 9 side of the intermediate transfer belt 8, a transfer device and a secondary transfer unit 13 as a second transfer unit are provided. The secondary transfer unit 13 includes a secondary transfer roller 14 and a secondary transfer roller cleaning unit 15.
In FIG. 1, portions indicated by two-dot chain lines and reference numerals 16 and 16a are portions according to the second example, the third example, and the fifth example, and are not disposed in the first example and the fourth example.

2 is a partial view schematically showing a secondary transfer portion of the image forming apparatus of the first example of the embodiment of the image forming apparatus according to the present invention, and FIGS. 3A and 3B are III in FIG. It is sectional drawing which follows the -III line.
As shown in FIGS. 2 and 3A, the rotation shafts 9a at both ends of the intermediate transfer belt drive roller 9 and the rotation shafts 14a at both ends of the secondary transfer roller 14 are rotatably supported by a support frame 47. . In this case, the rotation shaft 9a of the intermediate transfer belt drive roller 9 is supported so as to be rotatable only. The rotation shaft 14 a of the secondary transfer roller 14 is supported by a rectangular guide hole 47 a that extends in the support frame 47 toward the rotation center of the intermediate transfer belt drive roller 9. The rotation shaft 14a of the secondary transfer roller 14 is rotatable in the guide hole 47a and is linearly movable by being guided by the guide hole 47a. Further, the rotating shafts 14a at both ends of the secondary transfer roller 14 are always urged toward the intermediate transfer belt driving roller 9 by a load set by an urging means such as a spring 48 (corresponding to a pressure contact member of the present invention). Has been.

  As shown in FIG. 1, the secondary transfer roller 14 has a recess 17 that extends in the axial direction of the secondary transfer roller 14. Further, the secondary transfer roller 14 has a sheet-like elastic member 14c wound around the outer peripheral surface of the arc portion of the base material 14b. A resistance layer is formed on the outer peripheral surface of the arc portion of the secondary transfer roller 14 by the elastic member 14c.

  When the concave portion 17 is at the position shown in FIG. 1 not facing the intermediate transfer belt 8, the secondary transfer roller 14 is pressed against the intermediate transfer belt 8 by the aforementioned urging means. When the secondary transfer roller 14 is in pressure contact with the intermediate transfer belt 8 as described above, the rotating shaft 14a is urged from the end 47b of the guide hole 47a on the side of the intermediate transfer belt driving roller 9 as shown in FIG. Some separation against the load of the means.

  Then, the secondary transfer roller 14 is pressed (pressed) against the intermediate transfer belt 8, whereby a secondary transfer nip 13 a is formed between the intermediate transfer belt 8 and the elastic member 14 c of the secondary transfer roller 14. That is, the secondary transfer unit 13 of the first example is configured as a low load type transfer unit. At this time, the intermediate transfer belt driving roller 9 functions as a backup roller against the pressing of the secondary transfer roller 14.

When the concave portion 17 is at the position shown in FIG. 2 facing the intermediate transfer belt 8, the rotating shaft 14a of the secondary transfer roller 14 is moved by the aforementioned urging means as shown in FIGS. Further, it is in contact with the end 47b of the guide hole 47a, and any further movement toward the secondary transfer roller 14 is prevented. That is, the end 47b of the guide hole 47a constitutes a transfer roller position restricting portion 47b that restricts the position of the secondary transfer roller 14 (hereinafter, the same reference numerals are also used for the transfer roller position restricting portion for convenience of explanation). In a state where the position of the secondary transfer roller 14 is regulated by the end 47b, the elastic layer 14c of the secondary transfer roller 14 does not contact the intermediate transfer belt 8.

  The elastic layer 14c does not contact the intermediate transfer belt 8. The inter-axis distance L2 between the secondary transfer roller 14 and the intermediate transfer belt driving roller 9 shown in FIG. 3B is such that the elastic layer 14c contacts the intermediate transfer belt 8. 3 is slightly smaller than the inter-axis distance L1 between the secondary transfer roller 14 and the intermediate transfer belt drive roller 9 shown in FIG. Therefore, the relative position between the secondary transfer roller 14 and the intermediate transfer belt drive roller 9 when the concave portion 17 of the secondary transfer roller 14 does not face the position corresponding to the secondary transfer nip and when it faces the position equivalent to the transfer nip. The change is very slight.

  Here, the position corresponding to the secondary transfer nip has the following meaning. That is, when the concave portion 17 comes to a position facing the intermediate transfer belt driving roller 9, the concave portion 17 (specifically, the concave portion forming portion) of the secondary transfer roller 14 does not contact the intermediate transfer belt 8. For this reason, the secondary transfer nip 13 a is not formed between the intermediate transfer belt 8 and the secondary transfer roller 14. Therefore, the secondary transfer roller 14 is formed in pressure contact with the intermediate transfer belt 8, and the secondary transfer nip 13a is formed at a position where the width of each rotation direction of the secondary transfer roller 14 and the intermediate transfer belt 8 is maximized. When the concave portion 17 faces the formation position of the secondary transfer nip 13a, it is referred to as a secondary transfer nip equivalent position.

  A gripper 18 as a transfer material gripping member of the present invention, a gripper support portion 19 as a transfer material gripping member receiving member on which the gripper 18 is seated, and a protruding claw 34 as a transfer material peeling member are disposed in the recess 17. ing.

  The gripper 18 has a gap between the tip 33a of the transfer material 33 fed from the gate roller 40 via the transfer material supply guide 41 and the gripper support portion 19 immediately before the concave portion 17 reaches the position corresponding to the secondary transfer nip. Grip to. In this case, the gripper 18 is entirely located in the recess when the transfer material 33 is gripped. Further, the gripper 18 is separated from the gripper support portion 19 after the concave portion 17 has passed the position corresponding to the secondary transfer nip, and releases the leading end portion 33 a of the transfer material 33.

  The secondary transfer roller 14 is applied with a transfer bias for transferring the toner image transferred to the intermediate transfer belt 8 onto a transfer material such as transfer paper. The secondary transfer roller 14 rotates in the direction of the arrow when the intermediate transfer belt 8 rotates in the direction of the arrow, and a transfer bias is applied to transfer the toner image on the intermediate transfer belt 8 to the transfer material at the secondary transfer nip 13a. Transfer to 33. At this time, the secondary transfer is performed with the transfer material 33 held by the gripper 18.

  The protruding claw 34 is normally in a retracted position where it is located in the recess 17 during normal operation, and is in a protruding position where its tip is positioned outside the recess 17 during operation. Then, the protrusion claw 34 is set to the protrusion position in tandem with the gripping release of the transfer material 3 by the gripper 18. At the protruding position of the protruding claw 34, the protruding claw 34 protrudes from the back surface of the transfer material 33 (the surface opposite to the toner image transfer surface) and peels from the secondary transfer roller 14.

  The secondary transfer roller cleaning unit 15 removes the liquid developer attached to the elastic member 14c of the secondary transfer roller 14 with a cleaning member such as a cleaning blade. The liquid developer removed by the cleaning member is collected in a liquid developer container.

Further, as illustrated in FIG. 1, the image forming apparatus 1 includes a first airflow generation device 42, a second airflow generation device 43, a transfer material transport unit 44, a third airflow generation device 45, and a fixing unit 46. ing. The first airflow generating device 42 blows air toward the leading end portion 33a of the transfer material 33 released from the gripping of the gripper 18 as indicated by an arrow. This prevents the leading end portion 33a of the transfer material 33 from moving with the intermediate transfer belt 8. The second airflow generator 43 sucks air in the arrow direction. The back surface of the transfer material 33 peeled from the secondary transfer roller 14 is sucked by the air suction of the second airflow generation device 43. As a result, the transfer material 33 is moved toward the transfer material conveyance unit 44 by the rotational force of the intermediate transfer belt 8 and the secondary transfer roller 14 while being guided by suction by the second airflow generation device 43.

The transfer material transport unit 44 includes an endless transfer material transport belt 44a that rotates in the arrow direction and a suction member 44b that sucks air in the arrow direction. The transfer material 33 that has moved to the transfer material transport unit 44 is transported toward the third airflow generation device 45 by the transfer material transport belt 44a while being sucked by the air suction of the suction member 44b. The third airflow generator 45 sucks air in the direction of the arrow. The back surface of the transfer material 33 peeled off from the secondary transfer roller 14 is sucked by the air suction of the third airflow generation device 45. Accordingly, the transfer material 33 is moved toward the fixing unit 46 by the rotational force of the transfer material conveyance belt 44 a while being guided by suction by the third airflow generation device 45. The toner image on the transfer material 33 is fixed by being heated and pressed by the fixing unit 46.
Since the other configuration and other image forming operations of the image forming apparatus 1 of the first example are the same as those of the conventional image forming apparatus using the liquid developer, the description thereof is omitted.

  According to the image forming apparatus 1 including the secondary transfer unit 13 of the first example, the secondary transfer roller 14 is always attached with a load set so that the secondary transfer roller 14 is pressed against the intermediate transfer belt 8 and the intermediate transfer belt drive roller 9. It is energized. When the concave portion 17 of the secondary transfer roller 14 does not face the position corresponding to the transfer nip, the rotation shaft 14a is separated from the transfer roller position restricting portion 47b formed by the end of the guide hole 47a. Further, when the concave portion 17 of the secondary transfer roller 14 faces a position corresponding to the transfer nip, the rotating shaft 14a and the transfer roller position restricting portion are brought into contact with each other. Therefore, when the concave portion 17 of the secondary transfer roller 14 faces the position corresponding to the transfer nip, the position of the secondary transfer roller 14 can be reliably regulated by the transfer roller position regulating portion 47b. Thus, when the concave portion 17 of the secondary transfer roller 14 faces the position corresponding to the transfer nip, the secondary transfer roller 14 is prevented from being too close to the intermediate transfer belt 8 and the intermediate transfer belt drive roller 9. It can suppress that the position of the next transfer roller 14 changes a lot.

By suppressing the change in the relative position between the secondary transfer roller 14 and the intermediate transfer belt 8, the contact between the secondary transfer roller 14 and the intermediate transfer belt 8 is ensured when the concave portion 17 faces the position corresponding to the transfer nip. By avoiding this, banding in secondary transfer can be suppressed. At this time, since the intermediate transfer belt 8 is not affected by the secondary transfer roller 14, banding in the primary transfer of the primary transfer portions 6Y, 6M, 6C, and 6K can be suppressed. As a result, the toner image can be stably transferred to the transfer material 33, and a good image can be formed.

  In particular, in the first example, since the intermediate transfer belt driving roller 9 and the secondary transfer roller 14 are integrally supported by the support frame 47, the relative position between the intermediate transfer belt driving roller 9 and the secondary transfer roller 14. Is more accurately positioned. Therefore, the holding of the transfer material 33 can be stabilized, and the transfer nip can be stably formed. This makes it possible to transfer the toner image onto the transfer material 33 even more stably.

  FIG. 4 partially and schematically shows a second example of the embodiment of the image forming apparatus according to the present invention, and is a partial view similar to FIG. 2, and FIGS. 5A and 5B are V- It is sectional drawing similar to Fig.3 (a), (b) along a V line.

As shown in FIG. 4, in the image forming apparatus 1 of the second example, the rotation shafts 14 a at both ends of the secondary transfer roller 14 are rotatably supported by a pair of secondary transfer roller support frames 16. The support frame 47 rotatably supports the rotation shaft 9 of the intermediate transfer belt drive roller 9 and the rotation shaft 16a of the secondary transfer roller support frame 16 (shown by a two-dot chain line in FIG. 1). In this case, the secondary transfer roller support frame 16 rotates and swings around the rotation shaft 16a (rotation fulcrum) and is urged in the direction of the arrow by a load indicated by an arrow of an urging means such as a spring (not shown). Yes.

The secondary transfer roller support frame 16 includes a transfer roller position restricting portion 47b having a semicircular cross section. As in the first example, the elastic layer 14c does not come into contact with the intermediate transfer belt 8. The inter-axis distance L2 between the secondary transfer roller 14 and the intermediate transfer belt drive roller 9 shown in FIG. This is slightly smaller than the inter-axis distance L1 between the secondary transfer roller 14 and the intermediate transfer belt driving roller 9 shown in FIG. Therefore, the relative position between the secondary transfer roller 14 and the intermediate transfer belt drive roller 9 when the concave portion 17 of the secondary transfer roller 14 does not face the position corresponding to the secondary transfer nip and when it faces the position equivalent to the transfer nip. The change is very slight.
Since other configurations, other image forming operations, and other functions and effects of the image forming apparatus 1 of the second example are the same as those of the image forming apparatus 1 of the first example, description thereof is omitted.

  6 is a partial view similar to FIG. 4 partially and schematically showing a third example of the embodiment of the image forming apparatus of the present invention, and FIGS. 7A and 7B are views of FIG. It is sectional drawing similar to FIG. 5 (a), (b) along a VII line.

  As shown in FIG. 6, in the image forming apparatus 1 of the third example, the support frame 47 in the image forming apparatus 1 of the second example also supports the gate roller 40 and the transfer material supply guide 41 integrally.

  Also in the third example, as in the first example, the elastic layer 14c does not contact the intermediate transfer belt 8, and the inter-axis distance L2 between the secondary transfer roller 14 and the intermediate transfer belt drive roller 9 shown in FIG. However, the elastic layer 14c is slightly smaller than the inter-axis distance L1 between the secondary transfer roller 14 and the intermediate transfer belt driving roller 9 shown in FIG. Therefore, the relative position between the secondary transfer roller 14 and the intermediate transfer belt drive roller 9 when the concave portion 17 of the secondary transfer roller 14 does not face the position corresponding to the secondary transfer nip and when it faces the position equivalent to the transfer nip. The change is very slight.

In the third example, the intermediate transfer belt drive roller 9, the secondary transfer roller 14, the gate roller 40 and the transfer material supply guide 41 are integrally supported by the support frame 47. The relative positions of the next transfer roller 14, the gate roller 40, and the transfer material supply guide 41 are positioned more accurately. Therefore, the conveyance of the transfer material 33 can be stabilized and the holding of the transfer material 33 can be further stabilized by the stable conveyance of the transfer material 33. This makes it possible to transfer the toner image onto the transfer material 33 even more stably.
Other configurations, other image forming operations, and other operational effects of the image forming apparatus 1 of the third example are the same as those of the image forming apparatus 1 of the first example and the second example. Omitted.

  FIG. 8 is a partial view similar to FIG. 2, partially and schematically showing a fourth example of the embodiment of the image forming apparatus of the present invention. FIGS. It is sectional drawing similar to FIG. 3 (a), (b) along an IX line.

As shown in FIG. 8, in the image forming apparatus 1 of the fourth example, the support frame 47 in the image forming apparatus 1 of the first example also supports the second airflow generation device 43 and the transfer material transport unit 44 integrally. Yes.

  Also in the fourth example, as in the first example, the elastic layer 14c does not contact the intermediate transfer belt 8, and the inter-axis distance L2 between the secondary transfer roller 14 and the intermediate transfer belt drive roller 9 shown in FIG. However, the elastic layer 14c is slightly smaller than the inter-axis distance L1 between the secondary transfer roller 14 and the intermediate transfer belt driving roller 9 shown in FIG. Therefore, the relative position between the secondary transfer roller 14 and the intermediate transfer belt drive roller 9 when the concave portion 17 of the secondary transfer roller 14 does not face the position corresponding to the secondary transfer nip and when it faces the position equivalent to the transfer nip. The change is very slight.

In the fourth example, since the intermediate transfer belt drive roller 9, the secondary transfer roller 14, the second airflow generation device 43, and the transfer material transport unit 44 are integrally supported by the support frame 47, the intermediate transfer belt drive The relative positions of the roller 9, the secondary transfer roller 14, the second airflow generation device 43, and the transfer material transport unit 44 are more accurately positioned. Therefore, the transfer of the transfer material 33 after the transfer can be stabilized. This makes it possible to reliably transfer the transferred transfer material 33 to the next processing unit such as the fixing unit 46.
Other configurations, other image forming operations, and other functions and effects of the image forming apparatus 1 of the fourth example are the same as those of the image forming apparatus 1 of the first example, and thus description thereof is omitted.

FIG. 10 is a partial view schematically showing a fifth example of the embodiment of the image forming apparatus according to the present invention, which is the same as FIG. 2, and FIGS. It is sectional drawing similar to FIG. 3 (a), (b) along X-ray I.
As shown in FIG. 10, in the image forming apparatus 1 of the fifth example, the second airflow generating device 43 and the transfer material conveying unit 44 are also integrally supported on the support frame 47 in the third example as in the fourth example. I am letting.

  Also in the fifth example, as in the first example, the elastic layer 14c does not contact the intermediate transfer belt 8, and the inter-axis distance L2 between the secondary transfer roller 14 and the intermediate transfer belt driving roller 9 shown in FIG. However, the elastic layer 14c is slightly smaller than the inter-axis distance L1 between the secondary transfer roller 14 and the intermediate transfer belt drive roller 9 shown in FIG. Therefore, the relative position between the secondary transfer roller 14 and the intermediate transfer belt drive roller 9 when the concave portion 17 of the secondary transfer roller 14 does not face the position corresponding to the secondary transfer nip and when it faces the position equivalent to the transfer nip. The change is very slight.

In the fifth example, the second airflow generation device 43 and the transfer material transport unit 44 are integrally supported by the support frame 47 in the third example as in the fourth example. Therefore, also in the fifth example, it is possible to obtain an operational effect based on a configuration in which the second airflow generation device 43 and the transfer material transport unit 44 are integrally supported on the support frame 47 in the fourth example.
Other configurations, other image forming operations, and other functions and effects of the image forming apparatus 1 of the fifth example are the same as those of the image forming apparatus 1 of the third example, and thus description thereof is omitted.

  The transfer device and the image forming apparatus of the present invention are not limited to the examples of the above-described embodiments. For example, in each of the above-described examples, the intermediate transfer belt 8 is used as the image carrier. However, an intermediate transfer drum can be used, and a photoconductor can be used as the image carrier. Needless to say, when a photoconductor is used as the image carrier, the toner image on the photoconductor is directly transferred to a transfer material. In each of the image forming apparatuses described above, the tandem type image forming apparatus is used. However, other types of image forming apparatuses or single color image forming apparatuses may be used. In short, the present invention can be modified in various ways within the scope of the matters described in the claims.

DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus, 2Y, 2M, 2C, 2K ... Photoconductor, 5Y, 5M, 5C, 5K ... Developing part, 6Y, 6M, 6C, 6K ... Primary transfer part, 8 ... Intermediate transfer belt, 9 ... Belt drive Roller, 13 ...
Secondary transfer portion (transfer device), 13a ... secondary transfer nip, 14 ... secondary transfer roller, 16 ... secondary transfer roller support frame, 16a ... rotation shaft (rotation fulcrum), 17 ... concave, 18 ... gripper, DESCRIPTION OF SYMBOLS 19 ... Gripper support part, 33 ... Transfer material, 33a ... Tip part, 34 ... Extrusion claw, 40 ... Gate roller, 41 ... Transfer material supply guide, 42 ... 1st airflow generator, 43 ... 2nd airflow generator , 44 ... transfer material conveying section, 45 ... third airflow generator, 46 ... fixing section, 47 ... support frame, 47a ... guide hole, 47b ... transfer roller position regulating section (end of guide hole)

Claims (8)

A transfer roller having a recess and being pressed against an image carrier that carries an image to form a transfer nip;
A pressing member that presses the transfer roller against the image carrier;
A restriction portion for restricting movement of the transfer roller by the pressure contact member when the recess faces the formation position of the transfer nip;
A transfer device comprising:   The transfer device according to claim 1, wherein the restricting portion is disposed on a support frame that supports the transfer roller. An image carrier for carrying an image;
A transfer roller having a recess and press-contacting the image carrier to form a transfer nip;
A pressing member that presses the transfer roller against the image carrier;
A restriction portion for restricting movement of the transfer roller by the pressure contact member when the concave portion of the transfer roller faces the transfer nip forming position;
An image forming apparatus comprising: A gate roller for feeding a transfer material to the transfer nip;
A support frame that supports the image carrier and the gate roller;
Have
The image forming apparatus according to claim 3, wherein the restricting portion is disposed on the support frame. A gate roller for feeding a transfer material to the transfer nip;
A transfer material supply guide for guiding a transfer material fed to the transfer nip;
A support frame that supports the image carrier, the gate roller, and a transfer material supply guide;
The image forming apparatus according to claim 3, wherein the restricting portion is disposed on the support frame. A transfer material guide for guiding the transfer material that has passed through the transfer nip; and
A support frame that supports the image carrier and the transfer material guide;
Have
The image forming apparatus according to claim 3, wherein the restricting portion is disposed on the support frame. A gate roller for feeding a transfer material to the transfer nip;
A transfer material guide for guiding the transfer material that has passed through the transfer nip; and
A support frame that supports the image carrier, the gate roller, a transfer material guide, and a transfer material guide;
Have
The image forming apparatus according to claim 3, wherein the restricting portion is disposed on the support frame. A first image carrier for carrying an image;
A first transfer unit for transferring an image of the first image carrier to a second image carrier;
A second transfer portion for transferring an image of the second image carrier to a transfer material;
Have
The second transfer portion is
A transfer roller having a recess and press-contacting with the second image carrier to form a transfer nip;
A pressing member that presses the transfer roller against the second image carrier;
A restriction portion for restricting movement of the transfer roller by the pressure contact member when the concave portion of the transfer roller faces the transfer nip forming position;
An image forming apparatus comprising:

Images