WO2001081218A1

WO2001081218A1 - Sheet offset device, sheet post-treatment device, and image forming device

Info

Publication number: WO2001081218A1
Application number: PCT/JP2001/003497
Authority: WO
Inventors: Koji Kirino
Original assignee: Omron Corporation
Priority date: 2000-04-24
Filing date: 2001-04-24
Publication date: 2001-11-01
Also published as: AU4884601A

Abstract

A sheet offset device, wherein first to third drums (31 to 33) are fitted to each other rotatably relative to each other, elongated first to third guide parts (41, 42, and 43) are formed in the drums (31 to 33), respectively, the second guide part (42) and third guide part (43) are inclined relative to the first guide part (41) and inclined opposedly to each other, an engaging pin (34) fixed to a drive shaft (25) for a delivery roller is inserted into the guide parts (41 to 43), whereby, when both drums (32) and (33) are set free to rotate with the first drum (31) rotated together with the delivery roller, the engaging pin (34) comes into the state of stoppage not moving in lateral direction, and the engaging pin (34) is moved leftward when only the rotation of the drum (32) is limited and moved rightward when only the rotation of the drum (33) is limited.

Description

Paper offset device, paper post-processing device, and image forming device

The present invention relates to a sheet offset device, a sheet post-processing device, and an image forming device. Background art

In an image forming apparatus such as a copying machine, a printer, and a facsimile, when discharging paper on which an image is formed, a discharge roller is reciprocated in a horizontal direction orthogonal to a discharge direction for sorting and the like. There is something. That is, the first position where the paper exit is positioned to hold the paper, and the second position where the paper is discharged by being moved in the lateral direction perpendicular to the discharge direction with respect to the first position. There is a device that can move between the first position and the second position so as to be able to take the and. Conventionally, as a lateral movement mechanism for reciprocating the discharge roller in the lateral direction as described above, a mechanism using a crank mechanism (for example, see Japanese Patent Application Laid-Open No. 3-42460) or a cylindrical cam is used. (For example, see Japanese Patent Application Laid-Open No. 3-38662).

On the other hand, a transport mechanism for supplying the paper is disposed upstream of the discharge roller in the paper discharge direction, and this paper transport mechanism is usually composed of a pair of upper and lower rollers in many cases. Conventionally, each roller for the paper transport mechanism has been made of metal from the viewpoint of durability and the like, and the paper is supplied in a state where the paper is sandwiched between a pair of upper and lower rollers. I have.

However, the conventional lateral movement mechanism described above has a problem that the crank and the cylindrical cam are used, so that the whole becomes considerably large. In addition, a crank or a dedicated driving source such as a motor for driving the cylindrical cam is required. However, there is a problem that the cost increases. In addition, since the movable part for reciprocating in the lateral direction is considerably large and heavy, it is difficult to speed up the reciprocating movement in the lateral direction in consideration of the inertia of the movable member. Short for direction There is a limit to the speed at which paper can be ejected.

On the other hand, in a paper transport mechanism composed of a pair of upper and lower metal rollers, the discharge roller moves from the first position to the second position with the paper straddling the discharge roller and the paper transport mechanism. If the paper is moved in the horizontal direction, the paper is likely to be damaged (the part of the paper that is sandwiched by the paper transport mechanism is easily damaged). In order to prevent such paper damage, it is necessary to start the lateral movement of the discharge rollers when the paper is completely discharged from the paper transport mechanism. Becomes a constraint. Disclosure of the invention

The present invention has been made in view of the above circumstances, and a first object of the present invention is to reduce the size of a lateral movement mechanism for reciprocating a discharge roller in a lateral direction and to reciprocate the lateral roller. Therefore, it is an object of the present invention to provide a paper offset device which does not require a dedicated driving source separately.

A second object of the present invention is to provide a sheet offset device that does not damage a sheet even when the discharge roller is moved in the horizontal direction even when the sheet exists between the discharge roller and the sheet transport mechanism. Is to provide.

A further object of the present invention is to provide a sheet post-processing apparatus and an image forming apparatus provided with these sheet offset apparatuses.

In order to achieve the first object, the present invention basically adopts the following solution. That is, as described in claim 1 of the claims,

The discharge roller moves back and forth between the first position where the discharged paper is held and the second position where the paper is moved in the horizontal direction perpendicular to the paper discharge direction and discharges the held paper. A paper offset device adapted to be moved, comprising a first drum and a second drum fitted so as to be relatively rotatable with each other, and an engaging pin integrated with the discharge roller and movable in the lateral direction. Is provided,

The first drum is engaged with the engagement pin so as to rotate integrally with the first drum, and A first guide portion for guiding the engagement pin in the lateral direction is formed, and the second drum is engaged with the engagement pin and extends at an angle with respect to the lateral direction. Part is formed,

A rotation restriction for restricting the rotation of the second drum and forcibly moving the engagement pin in the predetermined one of the lateral directions along the first guide portion according to the rotation of the first drum. Mechanism is provided,

Return means is provided for moving the engagement pin in a direction opposite to the predetermined one of the lateral directions.

It is like that. The above-mentioned returning means only needs to return the engaging pin to the original position.

In order to achieve the first object, the following solution method including the specific configuration of the return means can be adopted. That is, as described in claim 2 of the claims,

The discharge roller moves back and forth between the first position where the discharged paper is held and the second position where the paper is moved in the horizontal direction perpendicular to the paper discharge direction and discharges the held paper. A first drum, a second drum, and a third drum fitted to be rotatable relative to each other in a paper post-processing apparatus that is moved;

An engaging pin integrated with the discharge roller and movable in the lateral direction,

The first drum is formed with a first guide portion that engages with the engagement pin so as to rotate integrally and guides the engagement pin in the lateral direction.

A second guide portion is formed on the second drum, the second guide portion engaging with the engagement pin and extending obliquely with respect to the lateral direction.

The third drum is formed with a third guide portion that is engaged with the engagement pin and that is inclined and extends in a direction opposite to the second guide portion with respect to the lateral direction. By rotating only the second drum, the engagement pin is moved in any one of the lateral directions while rotating the third drum, and the engagement is restricted by regulating the rotation of only the third drum. The mating pin is the other of the horizontal directions Will be moved to

It is like that.

In the above solution, the discharge port, the engagement pin, and the first drum are rotated integrally with each other. However, when the second drum and the third drum are each free from rotation, the three drums are together with the engagement pin. It is assumed that the discharge rollers are not moved at all in the horizontal direction by being rotated synchronously. When the rotation of only the second drum is restricted (the first drum, the third drum, and the engagement pin rotate synchronously), the engagement pin slides with respect to the second guide 'according to the rotation of the first drum. The position of the engagement pin is changed while the engagement pin is moving, and the movement of the engagement pin with respect to the second guide portion is the movement of the engagement pin with respect to the first guide portion, that is, the movement in the lateral direction. When the rotation of only the third drum is restricted, the engaging pin is moved in the horizontal direction as in the above case, but the moving direction is the opposite of the inclination direction between the second guide part and the third guide part. , The direction is opposite to that when the rotation of the second drum is restricted. As described above, by alternately regulating the rotation of the second drum and the third drum, the engaging pin, that is, the discharge roller is moved back and forth in the lateral direction.

Since the first drum is rotated according to the rotation drive of the discharge roller, a dedicated drive source for rotating the first drum is not required. In addition, the three drums are in a mating relationship with each other, and are compact as a whole, including the mating pin, so that the size of the drum can be reduced. In the lateral movement mechanism, the member reciprocated in the lateral direction may be substantially only the engaging pin, and the reciprocal inertia is small, so that the reciprocating movement in the lateral direction can be performed at a high speed.

By setting each guide section to be a long hole and setting the engaging pin so as to penetrate each guide section, transfer of force between the engaging pin and each drum, that is, lateral movement of the discharge roller is obtained. Movement is ensured. In addition, the inside / outside fitting positional relationship of each drum can be arbitrarily selected.

In order to regulate the rotation of the 2nd or 3rd drum, irregularities are formed on the outer peripheral surface of each drum at a predetermined pitch over the entire length in the circumferential direction. Rotation can be restricted by bringing a stopper member into contact with the uneven portion. The stopper member is an electromagnetic type, and the stopper member The contact (rotation regulation) and separation (rotation allowance) to the uneven part can be switched by the 〇N and OFF of the solenoid.

In order to restrict the rotation of the second or third drum, an electromagnetic clutch or the like may be used instead of the means for bringing the stopper member into contact with the uneven portion.

In order to achieve the first object, the following solution method including the specific configuration of the return means can be adopted. That is, as described in claim 5 of the claims,

The discharge roller moves back and forth between the first position where the discharged paper is held and the second position where the paper is moved in the horizontal direction perpendicular to the paper discharge direction and discharges the held paper. In a paper offset device adapted to be moved, a first drum and a second drum fitted so as to be rotatable relative to each other, and an engaging pin integrated with the discharge port and movable in the lateral direction. A rotation regulating mechanism for regulating the rotation of the second drum;

A torque limiter that permits relative rotation between the rotation restricting mechanism and the second drum when a predetermined torque or more is generated between the rotation restricting mechanism and the second drum; A spring for returning and biasing in one predetermined direction;

Has,

The first drum is formed with a first guide portion that engages with the engagement pin so as to rotate integrally and guides the engagement pin in the lateral direction within a predetermined movement range. A second guide portion is formed on the second drum, the second guide portion being engaged with the engaging pin and extending obliquely with respect to the lateral direction.

While the first drum is rotating, the rotation restricting mechanism is operated to restrict the rotation of only the second drum, so that the engaging pin is moved in the lateral direction by the guiding action of the second guide portion. Of the engagement pin is moved in the other direction opposite to the predetermined direction, and the operation of the rotation restricting mechanism is performed in a state where the movement of the engagement pin in the other direction is restricted by the first guide portion. When the second pin is released and the second drum is rotated following the first drum, the spring moves the engagement pin in the predetermined direction. It is like that.

In the above solution, the discharge port, the engagement pin, and the first drum are rotated integrally with each other. However, when the second drum is in a rotation-free state, the two drums are rotated synchronously with the engagement pin, and the discharge is performed. The rollers are not moved at all in the lateral direction. When the rotation of only the second drum is restricted (the first drum and the engagement pin are synchronously rotated), the engagement pin moves against the second guide portion against the spring according to the rotation of the first drum. The position of the engagement pin is changed while sliding, and the movement of the engagement pin with respect to the second guide part is the movement of the engagement pin with respect to the first guide part, that is, the movement in the other direction among the lateral directions. Becomes

If the rotation restricting mechanism is still operating in a state where the engagement pin is located at the end in the other direction and the movement in the other direction is further restricted by the first drum, that is, the first guide portion, the rotation is performed. The torque limiter is actuated by the large torque generated between the regulating mechanism and the second drum, and the second drum rotates with the first drum. Since the torque continues to be received, the second drum rotates only in the same direction as the first drum, and as a result, the engaging pin is positioned at the other end in the other direction against the urging force of the spring. Will continue.

When the operation of the rotation restricting mechanism is released while the engagement pin is located at the other end, the engagement pin is moved in one predetermined direction by the urging force of the spring. . In other words, while the second drum is relatively rotated with respect to the first drum by the biasing force of the spring in the opposite direction to the first drum, the engagement pin moves in one predetermined direction in accordance with the relative rotation. Will be moved.

Since the first drum is rotated according to the rotation drive of the discharge roller, a dedicated drive source for rotating the first drum is not required. In addition, the two drums are in a fitting relationship with each other, so that the entire drum including the engaging pin is compact and can be reduced in size. In addition, the lateral movement member for moving the discharge roller in the lateral direction may be substantially only the engaging pin, and the reciprocating inertia is small, so that the reciprocating movement in the lateral direction can be performed at a high speed. .

Each guide has a long hole shape, and the engagement pin is set to penetrate each guide By doing so, the transfer of the force between the engagement pin and each drum, that is, the movement of obtaining the lateral movement of the discharge roller is reliably performed. In addition, the inside / outside fitting positional relationship of each drum can be arbitrarily selected.

The rotation restricting mechanism may be an electromagnetic type. In this case, at least a part or all of the portion of the discharge roller that is fitted to the first drum is formed of a non-magnetized material so that the electromagnetic force of the rotation restricting mechanism does not act on the discharge roller that contacts the paper. It is preferable to keep it. As the rotation restricting mechanism, a type in which a substantially disk-shaped member is pressed against a fixed member can be adopted. The rotation restricting mechanism can be arranged in series in the lateral direction with respect to the two drums. In addition, the rotation restricting mechanism can be arranged in a substantially cylindrical shape and disposed on the outer periphery of the two drums.

An appropriate type of spring can be adopted as long as it urges the engaging pin in a predetermined direction, and its installation position can be arbitrarily selected. For example, it can be set so as to apply a biasing force in a direction in which the substantially disc-shaped member of the rotation regulating mechanism is separated from the fixed member, and a torsion spring provided between the two drums can be provided. It can also be in the form.

In order to achieve the second object, the following solution is adopted in the present invention. That is, as described in claim 13 of the claims,

The discharge roller is moved between a first position for holding the discharged paper and a second position for discharging the held paper by moving the discharge roller in a lateral direction perpendicular to the discharge direction of the paper. In the sheet post-processing apparatus configured to reciprocate at a position upstream of the discharge roller, a sheet transport mechanism for supplying a sheet to the discharge port is disposed.

The paper transport mechanism is configured to be able to transport paper in a direction inclined with respect to the discharge direction and the lateral direction, respectively.

It is like that.

According to the above solution, even if the discharge roller is moved in the horizontal direction in a state where the paper is present across the discharge roller and the paper transport mechanism, the paper transport mechanism recognizes the oblique movement of the paper accompanying the lateral movement. Because it is allowed, paper damage is prevented. Also, emissions The fact that the discharge port can be moved in the horizontal direction even in a state where the paper exists across the roller and the paper transport mechanism is preferable from the viewpoint of performing high-speed discharge of the paper.

In order to be able to supply the paper obliquely in the paper transport mechanism, the driving member for feeding and driving the paper can be configured as a belt member. In this case, the belt member may be in the form of an endless belt that extends in a substantially horizontal direction, and the endless belt member is provided on a feed-side portion (a portion that moves in the paper transport direction). The paper can be conveyed while the paper is placed. It is preferable to provide a guide member on the upper side of the feed side to prevent the paper from being separated upward from the feed side. This guide member can be lengthened in the paper transport direction along the feed side. However, when the paper is conveyed, the gap formed between the feed side and the guide member should be as small as possible so that the paper does not come into strong contact with the guide member and create a large resistance. It is better to set it to be larger. In order to allow the paper to be fed obliquely in the paper transport mechanism, the outer peripheral portion of at least one of the pair of rollers for holding the paper can be formed by an elastic member. In this case, when the paper is moved laterally while the paper straddles the paper discharge mechanism and the paper transport mechanism, the elastic member is deformed as the paper is inclined with respect to the paper transport mechanism, and the paper is damaged. It is prevented from receiving. As the elastic member, various materials can be used. For example, a sponge has a large number of bubbles inside, and is sufficiently elastic with a weak force (a minimum force that damages the paper). It is preferable to use one that can be deformed.

The sheet post-processing apparatus and image forming apparatus according to the present invention include the sheet offset apparatus as described above.

Other objects and advantages of the present invention will become apparent from the following description of embodiments. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a simplified side view showing an example in which the present invention is applied to a copying machine. FIG. 2 is a perspective view showing a sheet post-processing apparatus according to the present invention.

Fig. 3 is an exploded perspective view of the offset mechanism (lateral movement mechanism) shown in Fig. 2. It is.

FIG. 4 is a cross-sectional view at an engagement pin portion of the offset mechanism shown in FIG. FIG. 5 is a developed view for explaining the operation principle of the offset mechanism shown in FIG.

FIG. 6 is a side view of the offset mechanism shown in FIG. 2, showing a state in which the engagement pins are stopped.

FIG. 7 is a side view of the offset mechanism shown in FIG. 2 and shows a state where the engaging pin is moved to the left.

FIG. 8 is a side view of the offset mechanism shown in FIG. 2, showing a state where the engagement pin is moved rightward.

FIG. 9 is a simplified perspective view showing a state in which a sheet is conveyed.

FIG. 10 is a simplified perspective view showing how a sheet is conveyed.

FIG. 11 is a simplified perspective view showing how a sheet is conveyed.

FIG. 12 is a simplified perspective view showing how a sheet is conveyed.

FIG. 13 is a simplified perspective view showing how a sheet is conveyed.

FIG. 14 is a simplified perspective view showing how a sheet is conveyed.

FIG. 15 is a perspective view showing a paper offset device according to another embodiment of the present invention together with a paper transport mechanism.

FIG. 16 is an exploded perspective view of the offset device shown in FIG.

FIG. 17 is an enlarged perspective view of the offset device shown in FIG.

FIG. 18 is a side cross-sectional view of the offset device shown in FIG.

FIG. 19 shows an example of the rotation restricting mechanism in the offset device shown in FIG. 15, and is a side sectional view in a state where the rotation restriction is released.

FIG. 20 is a side cross-sectional view showing a state in which the rotation restricting mechanism is operated to restrict the rotation from the state shown in FIG.

FIG. 21 shows the embodiment of FIG. 15 in which the engagement pin is moved in the other direction while being guided by the second guide portion in a state where the rotation restricting mechanism is operated and the rotation of the second drum is restricted. FIG. 7 is a development view showing a state of being performed.

FIG. 22 shows the embodiment of FIG. 15 in which the operation of the rotation regulating machine is released and FIG. 8 is a development view showing a state in which the engagement pin is moved in one predetermined direction by a spring in a state where the two drums are free to rotate.

FIG. 23 is a side view showing the operation of the offset device in the embodiment shown in FIG.

FIG. 24 is a side view showing the operation of the offset device after the state shown in FIG. 23. FIG. 25 is a # 1 side view showing the operation of the offset device after the state of FIG. 24. FIG. 26 is a side view showing the operation of the offset device after the state shown in FIG. 25. FIG. 27 is a simplified perspective view showing how a sheet is conveyed in the embodiment shown in FIG.

FIG. 28 is a perspective view showing how the sheet after the state shown in FIG. 27 is conveyed. FIG. 29 is a perspective view showing how the sheet after the state shown in FIG. 28 is conveyed. FIG. 30 is a perspective view showing how the sheet after the state shown in FIG. 29 is conveyed. FIG. 31 is a perspective view showing how the sheet after the state shown in FIG. 30 is conveyed. FIG. 32 is a perspective view showing how the sheet after the state shown in FIG. 31 is conveyed. FIG. 33 shows another example of the offset device, and corresponds to FIG.

FIG. 34 shows another example of the image forming apparatus, and corresponds to FIG. FIG. 35 is a side view showing an example in which the mouth of the paper transport mechanism is formed of a flexible member.

FIG. 36 is a side view showing an example in which the paper transport mechanism is configured using a belt member. BEST MODE FOR CARRYING OUT THE INVENTION

FIG. 1 shows an example of the case where the present invention is applied to a copying machine F. In the drawing, reference numerals 1 to 4 denote stock sections of paper S, which are used from stock sections 1 to 4 arbitrarily selected. The paper S is supplied to the transfer drum 9 by the transfer rollers 5, 6, 7 or 8. An image is formed on the sheet S by the transfer drum 9, and the formed image is heated and fixed by the fixing roller 10. The sheet S is conveyed from the fixing roller 10 to the sheet post-processing device 11, and the offset device forming a part of the sheet post-processing device 11 is provided. (Transverse mechanism) 12 and is finally loaded on the tray 13.

An example of the sheet post-processing device 11 is shown in FIG. 2 together with the offset device 12. In FIG. 2, reference numeral 20 denotes a paper transport mechanism, and 21 denotes a discharge roller (discharge roller mechanism). The paper transport mechanism 20 includes a drive shaft 22 that is rotationally driven by a motor as a drive source (not shown), a pair of left and right drive rollers 23 integrated with the drive shaft 22, and a drive roller 23. It has a pair of left and right driven rollers 24 provided correspondingly. The discharge roller 21 includes a drive shaft (rotary shaft) 25 that is driven to rotate as described later, a pair of left and right drive rollers 26 integrated with the drive shaft 25, and a drive roller 26. It has a pair of left and right driven rollers 27 provided correspondingly. The drive shaft 25, that is, the drive port 26 is reciprocated in its axial direction (lateral direction) as described later, while the driven roller 27 is reciprocated in accordance with the reciprocation of the drive roller 26. (The cooperative mechanism for this is not shown).

The drive shaft 25 of the discharge roller 21 is configured to rotate integrally with the drive shaft 22 of the paper transport mechanism 20 via an offset mechanism 12 (lateral movement mechanism). That is, the toothed belt 30 is wound around a toothed pulley 28 integrated with the drive shaft 22 and a toothed pulley 29 provided on the offset mechanism 12. The interlocking relationship between the offset mechanism 12 and the discharge roller 21 will be described later.

Details of the offset mechanism 12 are shown in FIG. 3, FIG. 4, and FIG. 6 to FIG. In the figure, 31 is the first drum, 32 is the second drum, and 33 is the third drum. The first drum 31 has a cylindrical shape, and has an outer peripheral surface formed with a long hole-shaped first guide portion 41 extending long in the axial direction (the direction of movement of the discharge roller 21 in the lateral direction). Have been. The first guide portion 41 is formed as a pair at substantially symmetric positions in the radial direction. The toothed pulley 29 is formed around the outer periphery of one end of the first drum 31, and the first drum 31 is rotated in accordance with the rotation of the paper transport mechanism 20 (the drive shaft 22). Is to be rotated. The second drum 32 is also cylindrical, and a second guide portion 42 is formed on the outer peripheral surface thereof. The second guide portion 42 has a long hole shape and is formed in a spiral shape as a whole, and such a second guide portion 42 is also formed in a pair at substantially symmetrical positions in the radial direction. The third drum 33 is also cylindrical and has a third guide on its outer peripheral surface. The part 43 is formed. The third guide portion 43 has a long hole shape and is formed in a spiral shape as a whole, and such a third guide portion 43 is also formed in a pair at substantially radially symmetric positions. Each of the second guide portion 42 and the third guide portion 43 is formed so as to be inclined with respect to the first guide portion 41, and furthermore, the second guide portion 42 and the third guide portion 43 are formed. The part 43 is set so that its inclination directions are opposite to each other (see also FIG. 5).

The diameters of the drums 31 to 33 are different from each other, and the drums 31 to 33 are fitted so as to be able to rotate relative to each other due to the relationship of the inner and outer triple structures. In the embodiment, the first drum 31, the third drum 33, and the second drum 32 are arranged in order from the larger outer shape (inner diameter) to the smaller one. That is, the third drum 33 is fitted to the outer periphery of the second drum 32, and the first drum 31 is fitted to the outer periphery of the third drum 33. At the time of fitting, the second drum 32 is inserted and fitted into the first drum 31 from one end in the axial direction, and the third drum 33 is inserted from the other end in the axial direction. Mated.

One end of the drive shaft 25 of the discharge roller 21 described above is inserted into the offset mechanism 12, that is, into the second drum 32 having the smallest diameter. At one end of the drive shaft 25, a mounting hole 25a is formed, and the engaging pin 34 is fitted tightly (without retaining) in the mounting hole 25a. Each end of the engaging pin 34 projects outside the outer peripheral surface of the drive shaft 25 to a greater extent, and penetrates the guides 41 to 43 (particularly, see FIG. 4). As a result, in a free state where the rotation of both the second drum 32 and the third drum 33 is not restricted with respect to the first drum 31, each of the drums 31 to 33 and the engaging pin 34 is It is rotated integrally with the drive shaft 25 of the discharge roller 21. In particular, since the first guide portion 41 of the first drum 31 extends in parallel with the drive shaft 25, the first drum 31 always rotates integrally with the drive shaft 25 via the engagement pin 34. It has become to be. The engaging pins 34 fit the respective drums 31 to 33, and after inserting one end of the drive shaft 25 into the second drum 32, from the radially outer side, It is mounted so as to penetrate the guides 41 to 43 and the mounting holes 25a. A toothed pulley 35 is formed on the outer periphery of one end of the second drum 32, and the outer peripheral surface of the toothed pulley 35 constitutes an irregular portion for controlling rotation to be described later. Similarly, A toothed pulley 36 is formed around the outer periphery of the other end of the third drum 33, and the toothed pulley 36 forms a rotation-regulating portion to be described later. An electromagnetically driven first stopper member 37 is disengaged from the pulley 35. Similarly, the electromagnetically driven second stopper member 38 is disengaged from the pulley 36. The stopper member 37 (38) is engaged with the pulley 35 (36) when the solenoid 37 a (38 a) is turned on, for example, and the second drum 32 ( 3 Restrict the rotation of the drum 3 3). Conversely, when the solenoid 37 a (38 a) is turned off, the stopper member 37 (38) is separated from the pulley 35 (36) (disengagement), and the second drum is released. The rotation of 3 2 (the third drum 3 3) is not regulated at all. '' Each of the drums 31 to 33 is rotatably held by a holder 39 as shown in FIGS. 6 to 8. The holder 39 regulates the drums 31 to 33 so that they do not move in the axial direction. In the embodiment, the holder 39 holds the drive shaft 25 of the discharge port 21 in a rotatable manner at two places on both sides of each of the drums 31 to 33. 31 to 33 are rotatably held by a holder 39 via a drive shaft 25.

Next, the lateral reciprocation of the discharge roller 21 by the offset mechanism 12 will be described with reference to FIG. First, the rotation of the first drum 31 (see arrow a in FIG. 5), which is driven to rotate via the belt 30, is performed via the engagement pin 34 and the discharge roller 21 (of the drive shaft 25). Rotate (rotation corresponding to the paper S discharge direction). At this time, in a state where the rotations of the second drum 32 and the third drum 33 are not regulated (free state), the second drum 32 and the third drum 33 The first pin 31 is rotated synchronously with the first drum 31 so that the engaging pin 34 is not moved in the axial direction, that is, in the lateral direction with respect to the first drum 31 (the state shown in FIG. 6).

Consider a state in which the rotation of only the second drum 32 is restricted using the first stopper member 37 while the first drum 31 is rotating. At this time, the engagement pin 34 slides in the second guide portion 42 of the second drum 32 according to the rotation of the first drum 31 (see the broken arrow in FIG. 5). It is moved to the left in FIG. 5 along one guide part 41. That is, the discharge roller 21 is moved in the horizontal direction (the state shown in FIG. 7). ' Consider a state in which the rotation of only the third drum 33 is restricted using the second stopper member 38 while the first drum 31 is rotating. At this time, the engagement pin 34 slides in the third guide portion 43 of the third drum 33 according to the rotation of the first drum 31 (see the broken arrow a in FIG. 5). It is moved rightward in FIG. 5 along the first guide portion 41. In other words, the discharge roller 21 is moved in the lateral direction, but the lateral movement direction is opposite to the lateral movement direction when the rotation of only the second drum 32 is restricted (the state shown in FIG. 8). ). Thus, by alternately restricting the rotation of the second drum 32 and the third drum 33, the engaging pin, that is, the discharge roller 21 is reciprocated in the lateral direction.

Next, referring to FIGS. 9 to 14, the sheet S is transported in the horizontal direction using the offset mechanism 12, including the transfer of the sheet S from the sheet transport mechanism 20 to the discharge roller 21. The state of the movement and the discharge to the tray 13 will be described sequentially. First, as shown in FIG. 9, the thread S is transported from the paper transport mechanism 20 to the discharge rollers 21. In the state of FIG. 9, the paper S is still transported to the discharge rollers 21. Has not reached (the position of the discharge roller 21 at this time is the first position). As the transport of the paper S by the paper transport mechanism 20 proceeds, the leading end of the paper S in the transport direction is gripped by the discharge roller 21 (see FIG. 10). Further, the paper S advances in the transport direction, and is eventually separated from the paper transport mechanism 20 and is held by only the discharge roller 21 (see FIG. 11). Both the second and third drums 33 are in a free state in which rotation is not restricted (the state in FIG. 6).

When the paper S is held by the discharge rollers 21 alone, the state shown in FIG. 7 is obtained in which the rotation of only the second drum 32 is restricted. As a result, the discharge roller 21 starts to move leftward, that is, starts to move in the horizontal direction perpendicular to the paper transport (discharge) direction by the paper transport mechanism 20 (see FIG. 12). Even when the discharge roller 21 moves in the horizontal direction, the paper S continues to be transported in the discharge direction. In other words, focusing on the paper S, the movement is a combination of the movement in the discharge direction and the movement in the horizontal direction.

FIG. 13 shows a state in which the sheet S has been moved to the left by a predetermined amount by the discharge roller 21, that is, a position corresponding to the tray 13 (this position is the second position). In this state, by stopping the rotation of the second drum 32 (holding the state in FIG. 6), The paper S is completely discharged from the discharge rollers 21 (see FIG. 14), and is transferred to the tray 13. When the paper S is completely discharged from the discharge rollers 21, the state shown in FIG. 8 is reached in which the rotation of only the third drum 33 is restricted. This causes the discharge roller 21 to move rightward and return to the position shown in FIG. Thereafter, the same is repeated.

FIGS. 15 to 32 show another embodiment of the offset device, and the same components as those in the above-described embodiment are denoted by the same reference numerals, and the duplicate description thereof will be omitted.

The drive shaft 25 of the discharge roller 21 is configured to rotate integrally with the drive shaft 22 of the paper transport mechanism 21 via an offset device 112 (lateral movement mechanism) according to another embodiment. I have. That is, the toothed belt 30 is wound around a toothed pulley 28 integrated with the drive shaft 22 and a toothed pulley 29 provided on the offset device 112. The interlocking relationship between the offset device 1 12 and the discharge roller 21 will be described later. Details of the offset device 112 are shown in FIGS. 16 to 18. In the figure, reference numeral 13 1 denotes a first drum, and reference numeral 13 2 denotes a second drum. The first drum 13 1 has a cylindrical shape, and has an outer peripheral surface formed with a long hole-shaped first guide portion 141 extending in the axial direction (in the direction in which the discharge roller 21 moves in the lateral direction). ing. The first guide portion 141 is formed as a pair at substantially symmetric positions in the radial direction. The toothed pulley 29 is integrated with the outer periphery of one end of the first drum 13 1, and the first drum 13 1 is driven by the rotation of (the drive shaft 22 of) the paper transport mechanism 20. Is to be rotated.

The second drum 1332 is also cylindrical, and has a second guide portion 142 formed on its outer peripheral surface. The second guide portion 142 has a long hole shape and is formed in a spiral shape as a whole, and a pair of such second guide portions 142 are also formed at substantially radially symmetric positions. The second guide portion 142 is formed so as to extend obliquely with respect to the first guide portion 141.

The diameters of the drums 13 1 and 13 2 are different from each other, and the drums 13 1 and 13 2 are fitted so as to be rotatable relative to each other due to the inner and outer double structures. In the embodiment, the first drum 13 1 is rotatably fitted to the outer periphery of the second drum 13 2. At the time of fitting, the second drum 13 2 is connected to the first drum 13 1 at one end in the axial direction. It is inserted and fitted from the side. A bearing 133 fixed to a fixing member is interposed between the two drums 13 1 and 13 2.

One end of the drive shaft 25 of the discharge port 21 described above is inserted into the offset device 112, that is, into the second drum 132. At one end of the drive shaft 25, a mounting hole 25a is formed, and the engaging pin 1334 is fitted tightly (in a retaining state) in the mounting hole 24a. Each end of the engaging pin 134 projects outward beyond the outer peripheral surface of the drive shaft 25, and penetrates the guides 141, 142. As a result, in the free state where the rotation of both the second drum 13 and the second drum 13 2 is not restricted with respect to the first drum 13 1, each of the drums 13 1, 13 2 and the engaging pin 13 4 are ejected. The roller 21 is rotated integrally with the drive shaft 25. In particular, since the first guide portion 14 1 of the first drum 13 1 extends in parallel with the drive shaft 25, the first drum 13 1 is connected to the drive shaft 25 via the engagement pin 13 4. And is always rotated as one. The engaging pins 13 4 are fitted to the respective drums 13 1 and 13 2, and after inserting one end of the drive shaft 25 into the second drum 13 2, From the side, it is mounted so as to pass through each guide part 14 1, 14 2, and mounting hole 25 a. In FIG. 18, the cross section is taken in a direction perpendicular to the axis of the engagement pin 134, but the state in which the engagement pin 134 extends in the axial direction is shown in FIG. It is shown by the dash-dot line in the middle.

At one end of the second drum 13 2, there is formed a flange portion 13 2 a located on the outer side in the axial direction of the first drum 13 1, and this flange portion 13 2 a is provided with a torque limiter. It is connected to the rotation restricting mechanism 1 36 via 1 35. As shown in FIGS. 19 and 20, the rotation restricting mechanism 1336 is generally disk-shaped (shallow cup-shaped) as a whole, and is fixed to a thin ring-shaped fixing member 151. It has a ring-shaped coil 152 fixed to the member 151, and a shallow cup-shaped armature 1553. An annular brake member 154 is fixed to the fixing member 155, and an annular brake member 155 is also fixed to the armature 153. As a result, when the coil 15 2 is energized, the armature 15 3 is forcibly displaced toward the fixed member 15 1 by the electromagnetic force, and the two brake members 15 54 and 15 5 are brought into contact with each other. 15 3 is fixed to the fixing member 15 1 (rotational regulation of the armature 15 3). Thus, the rotation control mechanism 13 6 is disposed in series with the drums 13 1 and 13 2, and the offset device 1 This is preferable for preventing the diameter of 12 from increasing.

The torque limiter 135 has a first member 135A and a second member 135B. The first member 135A is fixed to the second drum 132. The second member 135B is attached to the armature 153 so as to be integrally rotatable and slightly displaceable in the axial direction (for example, spline fitting). The two members 135A and 135B are normally rotated integrally, but when a torque equal to or more than a predetermined value acts between the two members 135A and 135B, they are rotated relative to each other (torque limit operation). A shaft-like connecting member 137 made of a non-magnetizable substance (for example, synthetic resin) is integrated with one end of the drive shaft 25 fitted into the offset device 112. The connecting member 137 penetrates the armature 153, the coil 152, and the fixing member 151 so as to be rotatable relative to each other, and has a leading end extending outside the rotation regulating mechanism 136. A ring-shaped spring receiver 138 is attached to the distal end of the connecting member 137. A spring 139 is interposed between the spring receiver 138 and the armature 153. The spring 139 is a coil spring, fitted on the outer periphery of the connecting member 137, and each end thereof is seated on the spring receiver 138 or the armature 153. As described above, the spring 139 is set so as to act in a direction in which the armature 153 is separated from the fixing member 151. The spring 139 is compressed when the drive shaft 25 is displaced leftward in FIG. 18 with respect to the drums 131 and 132 under external force, and displaces the drive shaft 25 rightward in FIG. 18 when the external force is released. (Return). In this way, the spring 139 moves and returns the drive shaft 25 (that is, the engagement pin 134 and the discharge roller 21) to the right in FIG. 18, which is a predetermined direction. Note that the above-described inclination direction of the second guide portion 142 formed on the second drum 132 is opposite to the above-described predetermined direction in consideration of the rotation direction of the first drum 131 (the left side in FIG. 18). ) Is set to move the engagement pin 134 to.

Each of the drums 131 and 32 and the rotation restricting mechanism 136 are rotatably held by a holder 140 as shown in FIGS. 23 to 26 (see also a dashed line in FIG. 18). The holder 140 regulates the drums 131 and 132 and the rotation restricting mechanism 136 so as not to move in the axial direction. In addition, In the embodiment, the holder 140 holds two portions of the bearing 133 and the fixing member 151 in the rotation restricting mechanism 1336.

Next, referring to FIG. 21 and FIG. 22 showing each of the guide portions 14 1 and 14 2 in an expanded state, and referring also to FIGS. 23 to 26, the offset device 1 1 2 The reciprocating movement of the discharge roller 21 in the horizontal direction will be described. First, in a state where the engagement pins 13 4 (that is, the drive shaft 25 and the discharge roller 21) are at the first position located at the rightmost position in FIG. 18, they are driven to rotate via the belt 30. The rotation of the first drum 13 1 (see the arrow in FIG. 21) is performed by the drive shaft of the discharge roller 2 1 (via the engagement pin 34).

2 5) Rotate, (rotation corresponding to the paper S discharge direction). At this time, in a state where the rotation of the second drum 1332 is not regulated (free state), the second drum 1332 is synchronously rotated with the first drum 1331 via the engagement pin 1334. However, the engaging pin 1334 is not moved in the axial direction, that is, in the lateral direction with respect to the first drum 1331 (the state shown in FIG. 23).

Consider a state in which the rotation restricting mechanism 1336 is operated and only the second drum 1332 is restricted in rotation while the first drum 131 is rotating. At this time, the engaging pin 13 4 slides in the second guide portion 14 2 of the second drum 13 2 in accordance with the rotation of the first drum 13 1 (the broken line in FIG. 21). (See arrow 3)), and is moved leftward in FIG. 18 along the first guide portion 141. That is, the discharge roller 21 is moved in the lateral direction (the state shown in FIG. 24), and the spring 1 39 is compressed accordingly.

The second position is when the drive shaft 25, that is, the engagement pin 1 34 is located at the leftmost position in FIG. 18 (the state shown in FIG. 25).

It is assumed that 34 is located at the left end of the first guide portion 14 1 in FIG. 18 (when it is brought into contact). At this time, a large torque is generated between the second drum 13 2 and the rotation restricting mechanism 13 6 (the armature 15 3), but due to the operation of the torque limiter 135, the second drum 1 It is prevented that an excessive rotation restricting force acts on 32. In other words, at this time, the torque set by the torque limiter 13 5 exceeds the biasing force of the spring 13 9, and the second drum 13 2 The relative rotation in the direction opposite to the rotation direction of 31 is regulated, and the second position is maintained. When the operation of the rotation restricting mechanism 1 36 is released from the state shown in Fig. 25, the drive shaft 25, that is, the engagement pin 1 34 is moved rightward in Fig. 18 by the urging force of the spring 1 39. As shown in FIG. 26, the drive shaft 25, that is, the engagement pin 134 is finally returned to the first position shown in FIGS. 18 and 23. In FIG. 22, the direction of movement of the engagement pin 134 when the engagement pin 1334 is returned in one predetermined direction by the spring 13 is indicated by an arrow a, and the second guide portion 142 is moved in the axial direction. (Engagement pin 13 4 is displaced from 13 4 a to 13 4 b, and second guide part 14 2 is displaced from 14 2 a to 14 2 displaced into b). As described above, the rotation restriction and the release of the rotation restriction of the second drum 13 2 alternately stand, so that the engaging pin 13 4, that is, the discharge port 21 is reciprocated in the lateral direction. Become.

Next, referring to FIGS. 27 to 32, the sheet S is horizontally traversed using the offset device 1 12, including the transfer of the sheet S from the sheet conveying mechanism 20 to the discharge roller 21. The manner in which the sheet is moved in the direction and discharged to the tray 13 will be sequentially described. First, as shown in FIG. 27, the paper S is transported from the paper transport mechanism 20 to the discharge roller 21. In the state of FIG. 27, the paper S is still discharged from the discharge roller 21. Has not reached (the position of the discharge roller 21 at this time is the first position). When the transport of the paper S by the paper transport mechanism 20 proceeds, the leading end of the paper S in the transport direction is held by the discharge roller 21 (see FIG. 28). Further, the paper S advances in the transport direction, and is eventually separated from the paper transport mechanism 20 and is held by the discharge roller 21 alone (see FIG. 29). The state up to this point is a free state in which the rotation of the first drum 13 is not regulated.

When the paper S is held by the discharge roller 21 alone, the rotation restricting mechanism 1 36 is operated, and only the second drum 13 2 is restricted from rotating. As a result, the discharge roller 21 starts to move leftward, that is, starts to move in the horizontal direction perpendicular to the paper transport (discharge) direction by the paper transport mechanism 20 (see FIG. 30). Even when the discharge roller 21 moves in the horizontal direction, the paper S continues to be transported in the discharge direction. In other words, focusing on the sheet S, the movement is a combination of the movement in the discharge direction and the movement in the horizontal direction. FIG. 31 shows a state in which the sheet S has been moved to the left by a predetermined amount by the discharge roller 21, that is, a position corresponding to the tray 13 (this position is the second position). This state In this state, the paper S is completely discharged from the discharge rollers 21 (see FIG. 32), and is transferred to the tray 13. When the paper S is completely discharged from the discharge roller 21, the operation of the rotation restricting mechanism 13 6 is stopped, and the rotation of the second drum 13 3 is made free. As a result, the discharge roller 21 is laterally moved to the right by the urging force of the spring 13 and returned to the position shown in FIG. Thereafter, the same is repeated.

FIG. 33 shows a modification of the offset device 112 shown in FIG. In this example, the rotation restricting mechanism 1336 has a substantially cylindrical shape, and is disposed on the outer periphery of both drums 131, 132 in a fitting manner. In addition, one spring seat of the spring 13 9 is also used by the engagement pin 13 4. In the present embodiment, as compared with the case where the rotation restricting mechanism 1336 is arranged in series in the axial direction with respect to the two drums 131, 132 as shown in FIG. Can be shortened.

In the embodiment shown in FIGS. 15 to 33, a spring 13 9 is interposed between both drums 13 1 and 13 2 as a torsion spring, and a second drum 13 2 is connected to the first drum 13 It is also possible to set so as to apply a return biasing force to the first drum 13 so as to make it rotate relatively in the direction opposite to the rotation direction of the first drum 13 1.

FIG. 34 shows another embodiment (a modified example of FIG. 1) of the present invention. In the present embodiment, a case is shown in which the image forming apparatus F does not have the sheet post-processing apparatus 11 and the sheet after passing through the fixing roller 10 is immediately supplied to the sheet offset apparatus 12.

Here, the distance between the paper transport mechanism 20 and the discharge roller 21 (the distance in the paper transport direction) is relatively smaller than the length of the paper S in the transport direction, and the paper transport mechanism 20 and the discharge roller 21 are spaced apart from each other. Assume a state in which the paper S is held by both 1 and 2. If the discharge roller 21 is started to move in the lateral direction with the paper S held in both the paper transport mechanism 20 and the discharge roller 21, the paper S may be damaged. In the state where the paper S is held in the paper transport mechanism 20, even if the discharge roller 21 starts to move in the lateral direction, the paper transport mechanism 20 is moved so as not to damage the paper S. The paper S is prevented from being damaged by being configured to be able to transport the paper S in the direction inclined (slanted) with respect to the transport direction and the lateral direction, respectively. You.

An example in which the paper S can be transported in the above-described inclined direction by the paper transport mechanism 20 is shown in FIG. In this example, a pair of upper and lower rollers 51 and 52 for holding the paper S is used as the paper transport mechanism 20.One of the rollers 52 is a shaft member 52a and a shaft member 52a. And a cylindrical outer member 52b fitted to the outer periphery of the member. The outer member 52b is formed of a sufficiently soft elastic member, and is formed of a sponge in the embodiment. As a result, while the paper S is sandwiched between the pair of rollers 51 and 52, the discharge roller 21 is moved in the horizontal direction, and the paper S is slanted in the transport direction and the horizontal direction. Even if the sheet S is pulled in the direction, the external force that may damage the sheet S is absorbed by the elastic deformation of the outer member 53b, thereby preventing the sheet S from being damaged. The roller 51 may have a conventional structure, and at least the outer peripheral portion of the roller 51 may be formed of an elastic member. Alternatively, at least the outer peripheral portions of the rollers 51 and 52 may be formed of elastic members. Can also be formed.

FIG. 36 shows another example of preventing the paper S from being damaged. In this example, an endless belt member 61 is used as the paper transport mechanism 20. That is, the belt member 61 is formed of, for example, a sufficiently soft elastic member, extends substantially in the horizontal direction, and is disposed in an endless manner. The driving pulley is denoted by reference numeral 62, and the driven pulley is This is indicated by reference numeral 63. Of the belt members 61 between the pulleys 62 and 63, the upper feed side is denoted by reference numeral 61a, and the lower return side is denoted by reference numeral 61b. The width of the belt member 61 may be set to be approximately the same as the interval between the pair of left and right rollers 26 on the discharge roller 21, or may be set to be as wide as the lateral movement amount of the paper S. it can. Note that the driven pulley 63 is located near the discharge roller 21 so that the paper S is held by the paper transport mechanism 20 over a long distance in the transport direction.

A guide member 65 is disposed directly above the feed side 61 a in the belt member 61. The guide member 65 extends substantially over the entire length of the feed side 61a, and its lower surface 65a is a flat surface facing the feed side 61a. The lower surface 65 a is configured to form a parallel and small gap with respect to the feed side 6 la. The gap between the feed side 6 la and the lower surface 65 a is set slightly larger than the thickness of the paper S so that the guide member 65 does not become a resistance when the paper S is transported. Suppose that the discharge roller 21 holding the leading end of the paper S is moved laterally while the paper S is being conveyed while being placed on the feed side 61 a. At this time, the sheet S is smoothly and obliquely moved on the feed side 6 la with the lateral movement of the discharge roller 21, and is not damaged. The guide member 65 prevents the sheet S from floating from the feed side 61 a, but the guide member 65 does not give any resistance to the movement of the sheet S. Note that a roller may be provided instead of the guide member 65 (prevention of the upward separation from the paper S feed side 6 la by the roller).

The mechanism shown in FIGS. 35 and 36 can be similarly applied to the case where any of the offset devices 12 and 11 shown in FIGS. 2 and 15 is used. Industrial applicability

ADVANTAGE OF THE INVENTION According to this invention, the apparatus of a small and simple structure can be implement | achieved.

Claims

The scope of the claims

1. The discharge roller is moved between a first position for holding the discharged paper and a second position for discharging the held paper by moving the discharge roller in a lateral direction perpendicular to the discharge direction of the paper. In a paper offset device that is made to reciprocate between

An engagement pin having a first drum and a second drum fitted so as to be relatively rotatable with each other, the engagement pin being integrated with the discharge roller and capable of moving in the lateral direction;

Paper offset device characterized by the above-mentioned.

2. The discharge roller is moved between a first position for holding the discharged paper and a second position for moving the held paper by moving the paper in a lateral direction perpendicular to the paper discharge direction. In a paper offset device that is made to reciprocate between

A first drum, a second drum, and a third drum fitted to be rotatable relative to each other;

The first drum is formed with a first guide portion that engages with the engagement pin so as to rotate integrally and guides the engagement pin in the lateral direction. A second guide portion is formed on the second drum, the second guide portion engaging with the engagement pin and extending obliquely with respect to the lateral direction.

The third drum is formed with a third guide portion that is engaged with the engagement pin and that is inclined and extends in a direction opposite to the second guide portion with respect to the lateral direction. By rotating only the second drum, the engagement pin is moved in any one of the lateral directions while rotating the third drum, and the engagement is restricted by regulating the rotation of only the third drum. The mating pin is moved in the other one of the lateral directions,

Paper offset device characterized by the above-mentioned.

3. In Claim 2,

The first guide portion is formed as an elongated hole extending in the lateral direction,

The second guide portion and the third guide portion are formed as long holes extending spirally long;

The engagement pin penetrates each of the guide portions,

Paper offset device characterized by the above-mentioned.

4. In Claim 2,

On the outer peripheral surfaces of the second drum and the third drum, a large number of uneven portions are formed at predetermined pitches over the entire length in the circumferential direction,

An electromagnetic first stopper member which is engaged with and disengaged from the concave / convex portion formed on the second drum and regulates rotation of the second drum when engaged;

An electromagnetic second stopper member which is engaged with and disengaged from the concave and convex portions formed on the third drum and regulates rotation of the third drum when engaged;

Paper offset device characterized by the above-mentioned.

5. Move the discharge roller between the first position for holding the discharged paper and the second position for moving the held paper by moving it in the horizontal direction perpendicular to the paper discharge direction. In a paper offset device that is made to reciprocate between

A first drum and a second drum fitted so as to be relatively rotatable with each other; an engaging pin integrated with the discharge roller and movable in the lateral direction; A rotation regulating mechanism for regulating the rotation of the second drum,

¾

While the first drum is rotating, the rotation restricting mechanism is operated to restrict the rotation of only the second drum, so that the engaging pin is moved in the lateral direction by the guiding action of the second guide portion. Of the engagement pin is moved in the other direction opposite to the predetermined direction, and the operation of the rotation restricting mechanism is performed in a state where the movement of the engagement pin in the other direction is restricted by the first guide portion. When the second drum is released and rotated following the first drum, the spring moves the engagement pin in the predetermined direction.

Paper offset device characterized by the above-mentioned.

6. In Claim 5,

The second guide portion is formed as a long hole extending in a spiral shape, and the engaging pin penetrates each guide portion.

Paper offset device characterized by the above-mentioned.

7. In Claim 5,

The rotation restricting mechanism is configured to restrict the rotation of the second drum by pressing a substantially disc-shaped member rotated together with the second drum against a fixed member by electromagnetic force.

Paper offset device characterized by the above-mentioned.

8. In Claim 7, The paper offset device, wherein the spring is set to operate in a direction in which the substantially disk-shaped member is separated from the fixing member.

9. In Claim 5,

The paper offset device, wherein the rotation regulating mechanism has a substantially cylindrical shape and is disposed so as to surround the outer circumferences of the first drum and the second drum.

10. In claim 5,

The paper offset device, wherein the rotation restricting mechanism is disposed in series in the lateral direction with respect to the first drum and the second drum.

1 1. In Claim 5,

A sheet offset device, wherein a part or all of a portion of the discharge roller fitted to the first drum is formed of a non-magnetic material.

1 2. In claim 5,

The paper offset device, wherein the spring is a torsion spring disposed between the first drum and the second drum.

1 3. The paper to be discharged by the discharge roller: The first position where the paper is held, and the second position where the paper is moved in the horizontal direction that is perpendicular to the paper discharge direction and the paper that is held is discharged. In a paper offset device that is reciprocated between and

A paper transport mechanism for supplying paper to the discharge roller is disposed upstream of the discharge roller,

The paper transport mechanism is capable of transporting paper in a direction inclined with respect to the discharge direction and the lateral direction, respectively.

Paper offset device characterized by the above-mentioned.

1 4. In claim 13,

The paper offset device, wherein the paper transport mechanism includes a belt member driven to move the paper in the discharge direction.

15. In claim 14,

The belt member is of an endless type extending substantially horizontally,

A guide disposed above a feed side of the belt member on which the paper is placed and transported Having members,

The guide member is set to extend in the discharge direction and to have a gap larger than the thickness of the sheet with respect to the feed side.

Paper offset device characterized by the above-mentioned.

16. In claim 13,

The paper transport mechanism includes a pair of rollers for nipping the paper,

An outer peripheral portion of at least one of the pair of rollers is formed of an elastic member. '

17. A paper post-processing device, comprising the paper offset device according to any one of claims 1 to 16. ,

18. An image forming apparatus comprising the paper offset device according to any one of claims 1 to 16.