JP7124399B2 - Conveying device and image forming device - Google Patents

Description

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

Conventionally, techniques related to paper feeding in which paper is conveyed through a pair of rolls (first rolls) generally called registration rolls, registration rollers, etc. are described in Patent Documents 1 and 2 shown below, for example. are known.

In Patent Document 1, a registration roller is arranged in a transfer path of a transfer sheet, and a first transfer roller is arranged upstream of the registration roller and substantially in the center in the width direction of the transfer sheet conveyed on a support shaft. and a second transport roller arranged upstream of the first transport roller and releasing the transfer paper from a state in which the transfer paper is sandwiched when the transfer paper is slackened before the registration roller. In the second transport roller, when the transfer paper is slackened in front of the registration roller, the length of the transfer paper in the transport direction is short, and even if the transfer paper contacts the registration roller, the end of the transfer paper is When it is not sandwiched between the second transport rollers, it is in a pressure holding state, and even if the length of the transfer paper in the transport direction is long and the transfer paper comes into contact with the registration rollers, the edge of the transfer paper does not touch the second transport rollers. A paper conveying device is disclosed which is provided with pressurizing means for releasing the transfer paper from the sandwiched state when the transfer paper is pinched.

Japanese Patent Laid-Open No. 2002-200001 describes a paper length information obtaining means for obtaining information on the length of a sheet in the conveying direction, and at least two pairs of means for conveying the sheet that are rotatably arranged in order at intervals along the conveying direction. are rotatably installed on the downstream side in the sheet conveying direction of the second conveying roller pair, and form slack by protruding the tip of the sheet in the conveying direction while the rotation is stopped. A pair of registration rollers for correcting skew of the paper and a pair of first and second conveying rollers are connected to each other. When it is determined that the paper length information from the nip on/off mechanism means and the paper length information acquisition means is longer than the arrangement distance of the three pairs of rollers set between the first conveying roller pair and the registration roller and control means for controlling opening of the nip of either one of the first and second transport roller pairs via nip on/off mechanism means.

Japanese Patent No. 3749778 JP 2014-61957 A

Conventionally, a pair of first rolls for transporting a recording medium to be transported after abutting the front ends thereof are arranged so as to meet at a position upstream of the first roll in the transport direction of the recording medium, and the recording medium is transported to the first roll. a plurality of conveying paths having a passage space through which the recording medium is conveyed toward the recording medium; and a pair of second rolls for conveying toward the first roll.
However, in such a conveying device, it is possible to suppress the oblique feeding of the first roll, in which the first roll feeds the paper in a posture that is inclined with respect to the conveying direction, and to secure the conveyability for a small-sized recording medium. It is not possible to reconcile

The present invention provides a conveying apparatus having a plurality of conveying paths, a position where the plurality of conveying paths join at a position on the upstream side in the conveying direction of a recording medium from a first roll, and a second roller disposed in each conveying path. At least one of a plurality of auxiliary rolls arranged at a position between the rolls and assisting the transport of the recording medium is small compared to the case of not adopting a configuration in which at least one of the plurality of auxiliary rolls is displaced so as to contact and separate from the other auxiliary rolls. A conveying device capable of suppressing oblique feeding of a first roll with respect to a recording medium conveyed from at least one of a plurality of conveying routes while ensuring conveyability for a recording medium of a size, and image formation using the same It provides an apparatus.

The conveying device of this invention (A1) is
a pair of first rolls for sending the recording medium to be conveyed after the leading end thereof abuts;
a plurality of transport paths arranged to join at a position upstream of the first roll in the transport direction of the recording medium and having a passage space through which the recording medium passes so as to be transported toward the first roll;
A pair of rollers disposed at positions separated from the first roll of the plurality of transport paths on the upstream side in the transport direction beyond the merging position, and transporting the recording medium toward the first roll on each transport path. a second roll;
a plurality of auxiliary rolls arranged at a position between the joining position of the plurality of transport paths and the second roll to assist transport of the recording medium;
with
At least one auxiliary roll among the plurality of auxiliary rolls is displaced away from other auxiliary rolls when conveying a recording medium longer than the distance between the first roll and the second roll, and configured to be displaced so as to come into contact with another auxiliary roll when conveying a recording medium shorter than the distance between the roll and the second roll,
The at least one auxiliary roll is configured to be displaced away from the other auxiliary roll by coming into contact with a moving cam attached to the rotating shaft of the other auxiliary roll to be brought into contact,
The cam includes a base portion attached via a blocking means for blocking transmission of power when a load exceeding a certain level is applied to the rotating shaft of the other auxiliary roll to be brought into contact, and one cam projection provided on the base portion. and one stopping protrusion provided at a position spaced apart from the cam protrusion of the base in the circumferential direction of the rotating shaft,
When the other auxiliary roll is rotated in the conveying direction of the recording medium, the cam projection portion of the cam collides with the cam to stop the rotation of the cam, and the other auxiliary roll is rotated in the conveying direction. When the cam is rotated in the opposite direction, the stopping projection of the cam collides with the rotating shaft of the at least one auxiliary roll to stop the rotation of the cam. Equipped with a contact part,
The cam rotates when the other auxiliary roll to be brought into contact is rotated in a direction opposite to the direction in which the recording medium is conveyed, and the cam protrusion contacts the rotating shaft of the at least one auxiliary roll. The stopping protrusion abuts against the stopping protrusion to stop the at least one auxiliary roll while separating the at least one auxiliary roll from the other auxiliary roll .

The conveying device of this invention (A2) is
a pair of first rolls for sending the recording medium to be conveyed after the leading end thereof abuts;
a plurality of transport paths arranged to join at a position upstream of the first roll in the transport direction of the recording medium and having a passage space through which the recording medium passes so as to be transported toward the first roll;
A pair of rollers disposed at positions separated from the first roll of the plurality of transport paths on the upstream side in the transport direction beyond the merging position, and transporting the recording medium toward the first roll on each transport path. a second roll;
a plurality of auxiliary rolls arranged at a position between the joining position of the plurality of transport paths and the second roll to assist transport of the recording medium;
with
At least one auxiliary roll among the plurality of auxiliary rolls is displaced away from other auxiliary rolls when conveying a recording medium longer than the distance between the first roll and the second roll, configured to be displaced so as to come into contact with another auxiliary roll when conveying a recording medium shorter than the distance between the roll and the second roll,
The at least one auxiliary roll is configured to be displaced away from the other auxiliary roll by coming into contact with a moving cam attached to the rotating shaft of the other auxiliary roll to be brought into contact,
The cam includes a base portion attached via a blocking means for blocking transmission of power when a load exceeding a certain level is applied to the rotating shaft of the other auxiliary roll to be brought into contact, and one cam projection provided on the base portion. and
a first abutting portion that stops the rotation of the cam by abutting the cam projection portion of the cam when the other auxiliary roll is rotated in the direction of conveying the recording medium; and the other auxiliary roll. A second abutment for stopping the rotation of the cam by abutting the cam projection portion of the cam in contact with the rotating shaft of the at least one auxiliary roll when the cam is rotated in the direction opposite to the conveying direction. and
The cam rotates when the other auxiliary roll to be brought into contact is rotated in a direction opposite to the direction in which the recording medium is conveyed, and the cam protrusion contacts the rotating shaft of the at least one auxiliary roll. The at least one auxiliary roll is stopped in a state of being separated from the other auxiliary roll by hitting the second abutting portion .

The conveying device of this invention (A 3 ) is the conveying device of the above invention A1 or A2 , wherein the cam protruding portion of the cam has an arc-shaped curved surface at least at a portion that contacts the rotating shaft of the at least one auxiliary roll. It is what is done .

The conveying apparatus of this invention (A 4 ) is the conveying apparatus of any one of the above inventions A1 to A3 , wherein the at least one auxiliary roll is arranged on the outside of the plurality of conveying paths where adjacent conveying paths become one. is an outer auxiliary roll arranged outside the conveying path of the outer side, and is displaced so as to contact and separate from other auxiliary rolls in the outer conveying path.
The conveying apparatus of this invention ( A5) is the conveying apparatus of any one of the above inventions A1 to A3 , wherein the at least one auxiliary roll is arranged between adjacent conveying paths among the plurality of conveying paths. It is an inner auxiliary roll that is in contact with and displaces from and away from the other auxiliary rolls in both of the adjacent transport paths.
The conveying apparatus of this invention (A 6 ) is the conveying apparatus of any one of the above inventions A1 to A3 , wherein the conveying apparatus of the plurality of auxiliary rolls is arranged such that the conveying paths adjacent to each other in the plurality of conveying paths are one. At least one of the outer auxiliary rolls arranged outside the path is displaced so as to come into contact with and separate from other auxiliary rolls in the outer conveying path, and in the plurality of conveying paths among the plurality of auxiliary rolls An inner auxiliary roll arranged between adjacent conveying paths is displaced so as to come into contact with and separate from other auxiliary rolls in both adjacent conveying paths.

In addition, the image forming apparatus of the present invention (B1) includes an image forming unit for forming an image on a recording medium, and a pair of first rolls for feeding the recording medium conveyed from a plurality of conveying paths after the leading edges of the recording medium are brought into contact with each other. and a conveying device for conveying the sheet to the image forming section via the conveying device, wherein the conveying device includes the conveying device according to any one of the inventions A1 to A6 .

According to the transporting devices of the inventions A1 , A2 , A4, A5 and A6 , in the transporting device having a plurality of transporting paths, the plurality of transporting paths merge at a position upstream of the first roll in the transporting direction of the recording medium. At least one of a plurality of auxiliary rolls arranged at a position between the confluence position of the conveying routes and the second roll arranged on each conveying route to assist the conveying of the recording medium, and the other auxiliary rolls Compared to the case where the configuration of displacing so as to contact and separate is not adopted, the first roll for the recording medium conveyed from at least one of the plurality of conveying paths while ensuring the conveyability for the small-sized recording medium. Oblique feeding can be suppressed.
Further, according to the conveying devices of the inventions A1, A2, A4, A5 and A6, a means for attaching the cam for displacing the auxiliary roll is added compared to the case where the cam is not attached to the rotating shaft of the other auxiliary roll. There is no need to set Furthermore, according to the conveying devices of the inventions A1, A2, A4, A5 and A6, compared to the case where the cam attached to the rotating shaft of the other auxiliary roll is rotated without using the driving force of the other auxiliary roll, No additional drive means for driving the cams need be provided.

According to the conveying device of the invention A3 , compared to the case where the portion of the cam protrusion that contacts the rotating shaft of the at least one auxiliary roll is not configured with an arc-shaped curved surface, the at least one auxiliary roll It is possible to smoothly perform the operation of displacing so as to contact and separate from the auxiliary roll.

According to the image forming apparatus of the invention B1, in the conveying device having a plurality of conveying paths, the merging position of the plurality of conveying paths that joins at a position upstream of the first roll in the conveying direction of the recording medium and each conveying position Adopting a configuration in which at least one of a plurality of auxiliary rolls arranged at a position between the second roll arranged on the path and assisting the transport of the recording medium is displaced so as to come into contact with and separate from the other auxiliary rolls. Compared to the case where the first roll is not used, it is possible to suppress the oblique feeding of the first roll with respect to the recording medium conveyed from at least one of the plurality of conveying paths while ensuring the conveyability of the small-sized recording medium.

1 is a conceptual diagram showing configurations of a conveying device and an image forming apparatus according to Embodiment 1 and the like; FIG. 1 is a conceptual diagram showing a configuration of a conveying device according to Embodiment 1; FIG. (a) is a conceptual diagram showing the arrangement relationship of each roll in the conveying apparatus of FIG. 2, (b) is a conceptual diagram which shows the structure of some rolls in (a), and one state. (a) is a conceptual diagram showing the configuration and state of some of the auxiliary rolls in the conveying device of FIG. 2, and (b) is a conceptual diagram showing the configuration and another state of the auxiliary rolls in (a). FIG. 3 is a conceptual diagram showing configurations and states of cams and some auxiliary rolls in the conveying device of FIG. 2 ; 3 is a conceptual diagram showing an operation state when conveying a short recording medium and a long sheet of the conveying device of FIG. 2; FIG. 3 is a conceptual diagram showing a state when a long recording medium is conveyed by the conveying device of FIG. 2; FIG. FIG. 10 is a conceptual diagram showing configurations and states of a cam and some auxiliary rolls in a conveying device according to Embodiment 2; FIG. 11 is a conceptual diagram showing the configuration of a conveying device according to Embodiment 3; FIG. 10(a) is a conceptual diagram showing the arrangement relationship between rolls in the conveying apparatus of FIG. 9, and (b) is a conceptual diagram showing the configuration and one state of some rolls in (a). (a) is a conceptual diagram showing the configuration and state of some of the auxiliary rolls in the conveying apparatus of FIG. 9, and (b) is a conceptual diagram showing the configuration and another state of the auxiliary rolls in (a). FIG. 10 is a conceptual diagram showing an operation state when conveying a short recording medium and a long recording medium of the conveying device of FIG. 9; FIG. 11 is a conceptual diagram showing skew feeding of a first roll that occurs when a recording medium is conveyed in an obliquely inclined state in a conveying device for comparison;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

[Embodiment 1]
1 and 2 show an image forming apparatus equipped with a conveying device according to Embodiment 1. FIG. FIG. 1 shows the configuration of the image forming apparatus, and FIG. 2 shows the configuration of the conveying device in the image forming apparatus.
Arrows indicated by symbols X, Y, and Z in each drawing indicate directions of width, height, and depth of a three-dimensional space assumed in each drawing. In addition, in FIGS. 1, 2, etc., the circle mark at the portion where the arrows in the X and Y directions intersect indicates that the Z direction is vertically downward in the drawings.

<Configuration of Image Forming Apparatus>
As shown in FIG. 1, the image forming apparatus 1 according to the first embodiment includes an image forming unit 2 for forming an image on a sheet 9 based on image information, and an image forming unit 2 in the internal space of the housing 10. It is provided with a storage section 4 that stacks and stores the sheets 9 to be supplied, and a transport section 5 that transports the sheets 9 through a required transport path.
Here, the image information is, for example, information related to images such as characters, graphics, photographs, and patterns. The housing 10 is a structure formed into a desired shape by various support members, exterior materials, and the like. The housing 10 has a discharge/receiving section 12 formed on a part of the upper surface thereof, in which the sheets 9 to be discharged after the image is formed are stacked and stored.

The image forming unit 2 is configured as an electrophotographic image forming unit that forms an image made of a developer on a sheet of paper 9 . Specifically, the image forming unit 2 includes an image forming unit 20 that forms an unfixed image (toner image) made of a developer based on image information and transfers the image onto the paper 9, and the image forming unit 20 transfers the A fixing unit 35 for fixing the unfixed toner image on the paper 9 is provided.

Among them, the imaging unit 20 includes a charging device 22, an exposure device 23, a developing device 24, a transfer device 25, a cleaning device 26, and the like around a photosensitive drum 21, which is a drum-shaped photosensitive body that rotates in the direction indicated by the arrow. It is a part configured by arranging devices. In the image forming section 20, a portion where the photosensitive drum 21 and the transfer device 25 contact or face each other becomes a transfer position TP where the paper 9 is passed and the toner image is transferred.

In addition, the fixing unit 35 includes a heating rotator 37 that rotates in the direction indicated by the arrow, a pressurizing rotator 38 that contacts the heating rotator 37 under pressure and is driven to rotate, and the like. It is a part configured by arranging devices. In the fixing section 35, the portion where the heating rotator 37 and the pressure rotator 38 come into contact is a fixing processing section (fixing section) that passes the sheet 9 onto which the toner image has been transferred and performs fixing processing such as heating and pressing. Nip) becomes FN.

The accommodation portion 4 includes three accommodation portions, for example, a first accommodation portion 4A, a second accommodation portion 4B, and a third accommodation portion 4C.

Both the first accommodation portion 4A and the second accommodation portion 4B are cassette-type accommodation portions provided at positions below the image forming portion 2 of the housing 10. 44 and the like are arranged.

Each of the storage cassettes 41 and 42 has stacking plates 41a and 42a for stacking and storing a plurality of sheets of paper 9 in a required direction, and is a storage member attached to the outside of the housing 10 in a state in which it can be pulled out. is. Both of the supply devices 43 and 44 feed out the sheets 9A and 9B stacked on the stacking plates 41a and 42a of the storage cassettes 41 and 42 one by one from above and toward the image forming section 20 of the image forming section 2. It is a device that supplies

The third storage section 4C is a tray-type storage section provided outside of the side surface of the housing 10, and is configured by arranging devices such as a storage tray 46 and a supply device 47. As shown in FIG.

The storage tray 46 is a so-called manual feed tray, and is a collapsible type that accommodates a plurality of sheets of paper 9 stacked in a desired direction and is attached to the outside of the housing 10 so that it can be used in a folded state. is a housing member. The supply device 47 is a device that feeds and supplies the sheets 9C accommodated on the accommodation tray 46 one by one from above. The accommodation tray 46 and the supply device 47 are arranged at a position based on the paper entrance 13 provided on one side of the housing 10 .

As shown in FIG. 1, the conveying section 5 includes a first conveying section 5A, a relay conveying section 5B, a discharge conveying section 5C, a second conveying section 5D, a third conveying section 5E, and a double-sided conveying section 5B, which are examples of a plurality of conveying routes. It has six transport units called transport units 5F.

The first conveying portion 5A is a conveying portion that forms a conveying path for paper feeding (a path indicated by a dashed-dotted line curve) that connects the first accommodating portion 4A and the registration rolls 51 . The first transport unit 5A includes a transport roll 53, which is an example of a pair of second rolls arranged between the supply device 43 and the registration roll 51 of the first storage unit 4A, and a transport space for the paper 9A while forming a transport space for the paper. It is composed of a paper guide member (not shown) that guides 9A.

The relay conveying portion 5B is a conveying portion that forms a relay conveying path that connects between the registration roll 51 and the sheet introduction portion side and inside of the image forming portion 2 . The relay transport section 5B includes a sheet guide member (not shown) arranged between the registration roll 51 and the transfer position TP of the image forming section 20, and a sheet guide member arranged between the image forming section 20 and the fixing section 35. etc.
The discharge transport section 5</b>C is a transport section that forms a transport path for discharge that connects the paper discharge side of the image forming section 2 and the discharge roll 52 . The discharge/conveyance section 5C is composed of a pair of conveyance rolls 54 arranged between the fixing section 35 and the pair of discharge rolls 52, a paper guide member (not shown), and the like.

The second transport section 5D is a transport section that forms a transport path for paper feeding that connects the second storage section 4B and the registration rolls 51 . The second transport section 5D includes a pair of transport rolls 55 and 56 arranged between the supply device 44 of the second storage section 4B and the confluence J1 of the first transport section 5A, and a transport space for the paper 9B. It is composed of a paper guide member (not shown) that guides the paper 9B while forming it. Among these, the pair of transport rolls 56 is an example of a pair of second rolls.

The third conveying portion 5E is a conveying portion that forms a conveying path for paper feeding that connects between the third storage portion 4C and the registration rolls 51 . The third conveying portion 5E forms a conveying path that also joins the second conveying portion 5D at a junction J2 located upstream of the junction J1. The third transport section 5E forms a transport space for the paper 9C with a pair of transport rolls 56 arranged between the junction J2 with the second transport section 5D and the junction J1 with the first transport section 5A. and a paper guide member (not shown) that guides the paper 9C. The transport roll 56 in the third transport section 5E also serves as one transport roll 56 in the second transport section 5D.

The double-sided conveying section 5F is a conveying section that forms a conveying path for double-sided paper feeding that connects between the discharge roll 52 and the first conveying section 5A. The double-sided conveying section 5F includes a switching member 57 that displaces and switches the conveying destination of the paper 9 (A to C) in the direction indicated by the double-headed arrow in the vicinity of the junction with the discharge conveying section 5C, a discharge roll 52, and a first conveying unit. A pair of transport rolls 58a, 58b, 58c, and 58d arranged between the portion 5A and the junction J3 guides the paper 9R while forming a transport space for the paper 9R on which an image is formed on the back surface. It is composed of a paper guide member (not shown).

The registration rolls 51 are a pair of rollers 51 that feed the sheets of paper 9 (A to C, R) supplied from the storage units 4A to 4C to the image forming unit 2 (the transfer position in the image forming unit 20 thereof) after abutting the leading edges of the sheets. It is a roll as an example of the first roll of.
The discharge rolls 52 are a pair of rolls that discharge the paper 9 on which the image is formed from the discharge port 14 provided in the side surface of the housing 10 and store the paper in the discharge/accommodation section 12 .

The pair of registration rolls 51 is a combination of two rolls, namely a driving roll 51A that rotates and a driven roll 51B that rotates in contact with the driving roll 51A (FIG. 3). Both the driving roll and the driven roll are composed of a rotating shaft 511 and a plurality of roll bodies 512 fixed to the rotating shaft 511 (FIG. 3).

Further, the pair of discharge rolls 52 and the transport rolls 53, 54, 58a to 58d are also rolls that combine two rolls, a drive roll and a driven roll, in substantially the same manner as the registration roll 51. FIG.

<Image forming operation by image forming apparatus>
In this image forming apparatus 1, an image forming operation is performed as follows.

First, in the image forming apparatus 1, when a control means (not shown) receives a command requesting an image forming operation from an externally connected device or the like, the movable portions such as the image forming section 2, the housing section 4, and the conveying section 5 are operated at the required timing. Start. Here, as a representative example, the operation of forming an image on one side of the paper 9A supplied from the first container 4A will be described.

In the image forming section 2, as shown in FIG. 1, in the image forming section 20, the photosensitive drum 21 starts rotating in the direction indicated by the arrow, and the charging device 22 sets the outer peripheral surface of the photosensitive drum 21 to a desired potential. After charging, the exposing device 23 irradiates the charged outer peripheral surface of the photosensitive drum 21 with light (broken line arrow) corresponding to the image signal subjected to image processing to form an electrostatic latent image. After that, the developing device 24 in the image forming section 20 develops the electrostatic latent image by supplying and adhering toner of a desired color (for example, black) as developer. As a result, a toner image of a desired color is formed on the outer peripheral surface of the photosensitive drum 21 .

On the other hand, in the first conveying section 5A, the sheet 9A stored in the storage cassette 41 of the first storage section 4A is supplied to the image forming section 2 by the feeding device 43 in accordance with the operation timing of the image forming section 20 in the image forming section 2. is supplied toward the transfer position TP of the image forming unit 20 at. At this time, in the first transport unit 5A, after the paper 9A supplied from the first storage unit 4A by the supply device 43 is sent to the registration roll 51 via the transport roll 53, the registration roll 51 feeds it to the image forming unit at a required timing. 20 to the transfer position TP.

Subsequently, in the image forming section 20, the transfer device 25 transfers the toner image formed on the photosensitive drum 21 of the image forming section 20 onto the sheet 9A supplied from the first storage section 4A at the transfer position TP. In the image forming unit 20, the cleaning device 26 removes unnecessary substances such as toner and paper dust adhering to the outer peripheral surface of the photosensitive drum 21 after transfer, etc., to prepare for the next image forming process.

Subsequently, in the image forming section 2, the sheet 9A onto which the toner image has been transferred by the image forming section 20 is sent to the fixing section 35 via the relay conveying section 5B, and introduced into the fixing processing section FN in the fixing section 35. and let it pass. As a result, the toner image on the paper 9A is heated under pressure, melted, and fixed on the paper 9A.

Finally, the paper 9A after fixing is discharged from the fixing section 35 to the discharge/conveyance section 5C via the discharge/conveyance section 5C and is received in the discharge/container section 12 . At this time, the sheet 9A ejected from the fixing section 35 after fixing is conveyed by the transport rollers 54 in the ejection transport section 5C, and then ejected to the ejection storage section 12 through the paper ejection port 14 by the ejection rollers 52. .

By performing the series of operations described above, an image of a desired color is formed on one side of one sheet 9A, and the basic image forming operation is completed.
Further, in this image forming apparatus 1, when a command requesting image forming operation for a plurality of sheets of paper 9A is issued, the series of operations described above are similarly repeated for the number of sheets.

Furthermore, in this image forming apparatus 1, when an image forming operation for forming images on both sides of one sheet 9A is requested, the operation is performed as follows.
That is, the paper 9A on which the image formation on one side (front side) has been completed is conveyed by the discharge/conveyance unit 5C so as to be partially discharged from the paper discharge port 14, and then the discharge operation of the discharge roll 52 is stopped. Pause.
After that, the switching member 57 closes the discharge conveying section 5C and is displaced to open the double-sided conveying section 5F, and the discharge rollers 52 start to rotate in the direction opposite to the conveying direction in the double-sided conveying section 5F. As a result, the paper 9A is sent to the double-sided conveying section 5F as the paper 9R with the trailing edge side at the time of ejection facing forward so as to switch back, and then the first conveying is performed with the front and back surfaces being reversed. It is conveyed so as to merge with the section 5A.
Subsequently, the paper 9R (9A) is sent to the transfer position TP in the image forming unit 20 of the image forming unit 2 by the registration rolls 51 at a required timing, and the formation of the image on the opposite surface (back surface) of the paper 9R (9A) is performed by the image forming unit 2. , and finally stored in the discharge storage section 12 via the discharge transport section 5C.

Further, in the image forming apparatus 1, there is a request for an image forming operation on the paper 9B accommodated in the second accommodation portion 4B and a request for an image forming operation on the paper 9C accommodated in the third accommodation portion 4C. In this case, the above-described series of image forming operations are performed in substantially the same manner on one side or both sides of the paper sheets 9B and 9C supplied from the second storage section 4B or the third storage section 4C, respectively.

<Diagonal feeding of paper on the register roll>
By the way, in such an image forming apparatus 1, as illustrated in FIG. A phenomenon (oblique feeding of the registration rolls 51) may occur in which the sheet is fed in an oblique direction instead of in the direction along the conveying direction C.
The diagonal feed of the registration rolls 51 will be described by taking as an example a case where the sheet 9A stored in the first storage section 4A is transported via the first transport section 5A.

First, when the paper 9A stored in the first storage unit 4A is transported by the first transport unit 5A, it is transported to the pair of transport rolls 53 by the transport force of the supply device 43, and then is transported by the transport rolls 53. The sheet is sent to a pair of registration rolls 51 by the conveying force.
Subsequently, while the sheet 9A is being conveyed by the conveying rolls 53, the leading edge 9a of the sheet 9A is temporarily stopped by abutting against a pair of registration rolls 51 (between the driving roll and the driven roll). After that, the registration roll 51 starts to rotate at a required timing, and is sent to the image forming section 2 .

In this case, as illustrated in FIG. 13(a), when the paper 9A is conveyed to the registration rolls 51 in an attitude inclined with respect to the normal conveying direction C, the paper 9A is shown in FIG. 13(b). As shown in the example, between the stopped registration roll 51 and the conveying roll 53 being conveyed, the sheet is temporarily bent from the end 9c on the side that hits the registration roll 51 first to the opposite end 9d. Reference numeral 9t in the drawing indicates a curved portion of the paper 9. FIG. Reference numeral 90 indicated by a dashed rectangle in the figure indicates the paper being fed in a normal feeding attitude until the leading edge thereof reaches the registration rolls 51 .

Subsequently, the paper 9A begins to be fed from the registration rolls 51 when the registration rolls 51 begin to rotate.
At this time, the sheet 9A is sent out in a posture in which the front portion, which becomes the leading edge 9a, is substantially parallel to the axial direction B of the rotating shaft 511 of the registration roll 51, as illustrated in FIG. 13(c). At this time, the sheet 9A is fed with the curved portion 9t remaining in the transport path between the registration rolls 51 and the transport rolls 53 at the trailing end 9b of the sheet 9A. This curved portion 9 t disappears when the trailing edge 9 b of the paper 9 A exits the transport roll 53 .
Therefore, the sheet 9A conveyed in this oblique posture is corrected by the registration rollers 51 in its skewed conveying posture, and is conveyed in a normal conveying posture along the original conveying direction C as a whole. Become so.

However, in this case, depending on the length of the sheet 9A in the conveying direction C, the amount (size) of the curved portion 9t generated between the registration roll 51 and the conveying roll 53 is as shown in FIG. Since the left and right ends 9c and 9d in the axial direction B are different, the curved portion 9t of the end 9c has a relatively large amount, as shown in FIG. side is fed relatively faster to the registration rolls 51 than the opposite end 9d side.
As a result, depending on the length of the sheet 9A in the conveying direction C, as shown in FIG. , skewing of the registration rolls 51 as described above occurs.

Incidentally, the diagonal feeding of the registration rolls 51 is performed when the sheet 9B stored in the second storage section 4B is transported to the registration rolls 51 via the second transport section 5D, or when the sheet 9B is stored in the third storage section 4C. This may also occur when the sheet 9C on the sheet is conveyed to the registration roll 51 via the third conveying portion 5E.

Further, in the image forming apparatus 1 as described above, from the viewpoint of suppressing the diagonal feeding of the registration rolls 51, for example, the first transport roll 53 existing on the upstream side in the transport direction C of the sheet 9A from the registration rolls 51 can be moved from the registration rolls 51. It is said that it is effective to dispose the sheet 9A at a position as far away as possible, thereby weakening the influence of the holding force of the sheet 9A by the transport roll 53 from reaching the registration roll 51 side.
However, when the distance of the transport path between the transport rolls 53 and the registration rolls 51 is increased, it is possible to transport the paper (small size paper) 9 relatively short in the transport direction C toward the registration rolls 51 . It may become difficult or impossible.

Furthermore, in the image forming apparatus 1 having a plurality of transport paths for transporting the paper 9 toward the registration rolls 51, it is necessary to suppress the diagonal feeding of the registration rolls 51 and ensure the transportability of the small size paper 9. Reconciliation has not been realized.

<Detailed Configuration of Image Forming Apparatus>
Therefore, in this image forming apparatus 1, as shown in FIGS. , transport rolls 53 and 56 for transporting the sheet 9 toward the registration roll 51 in the first transport section 5A and the second transport section 5D, and each transport path (two transport paths) in the first transport section 5A and the second transport section 5D. path) merges with the transport rolls 53 and 56 in each of the transport paths, and assists the transport of the paper 9 in the two transport paths (depending on the case, (the transport rolls 53 and 56 A transport device 6A with three auxiliary rolls 61, 62, 63 (to) which participates in the transport of the sheet 9) is employed.

In addition, as shown in FIG. 3 and the like, the conveying device 6A in the image forming apparatus 1 has the auxiliary roll 63, which is one of the three auxiliary rolls 61 to 63, and the distance L1 between the registration roll 51 and the conveying roll 53. When conveying the paper 9A longer than L1, it is displaced so as to separate from the auxiliary roll 61 as another auxiliary roll, and when conveying the paper 9A shorter than the distance L1, it is displaced so as to come into contact with the auxiliary roll 61. be.

The conveying roll 53 in the conveying device 6A has the length L1 of the conveying path between the register roll 51 and the shortest sheet among the sheets 9 having the length in the conveying direction C in which the skew feeding of the register roll 51 is likely to occur. It is set to a value that can carry 9. The length L1 is set, for example, to a length (for example, 130 mm) that allows longitudinal feeding of A6 size paper according to Japanese Industrial Standards.
In addition, the length of the transport path between the transport roll 56 and the registration roll 51 is set to the same length as the length L1 in the case of the transport roll 53, but it may be set to a different length. do not have.

2 and 3, the three auxiliary rolls 61 to 63 in the conveying device 6A are a pair of rolls in which the two auxiliary rolls 61 and 62 are always in contact with each other on the conveying path of the second conveying section 5D. , and the remaining one auxiliary roll 63 forms a part of the conveying path of the first conveying section 5A and is arranged in a state capable of being displaced in directions approaching and separating from the auxiliary roll 61. ing.

Of these, the auxiliary roll 63 is positioned between the merging position J1 and the transport roll 53, and transports the paper 9A shorter than the length L1 of the transport path between the transport roll 53 and the registration roll 51. It is placed in a position where it can assist. The auxiliary roll 63 is arranged at a position where the length L2 of the conveying path between the registration roll 51 and the length L3 of the conveying path between the conveying roll 53 have different values, but the values are the same. can be placed in

In addition, the auxiliary roll 63 is arranged on the side of the transport path of the first transport section 5A away from the transport path of the second transport section 5D (the outside of the first transport section 5A where there is no adjacent transport section). ing. This auxiliary roll 63 is a roll composed of a rotating shaft 631 and a plurality of roll bodies 632 fixed to the rotating shaft 631, and is configured as a driven roll, as shown in FIG.

Specifically, the auxiliary roll 63 has its rotary shaft 631 rotatably supported by a support member (not shown) via a bearing 635, and rotates in a direction D1 in which it approaches the auxiliary roll 61 and a direction D2 in which it separates from the auxiliary roll 61. Displaceably supported. In addition, the bearing 635 of the auxiliary roll 63 is pressed with a required pressure F1 by a pressure spring 636, so that the roll body 632 is pressed against (the roll body 612 of) the auxiliary roll 61 with a required contact pressure. It's like

Next, the auxiliary rolls 61 and 62 are arranged in a state of being in constant contact at a position between the confluence position J1 and the transport roll 56 in the transport path of the second transport section 5D. In particular, since the auxiliary roll 61 needs to be able to contact the auxiliary roll 63, the length of the conveying path between the auxiliary roll 61 and the registration roll 51 is equal to the length of the conveying path between the auxiliary roll 63 and the registration roll 51. is arranged to have approximately the same length as the length L2 of .

The auxiliary roll 61 is arranged on the side of the transport path of the second transport section 5D adjacent to the transport path of the first transport section 5A (between the second transport section 5D and the first transport section 5A). The auxiliary roll 61 is a roll composed of a rotating shaft 611 and a plurality of roll bodies 612 fixed to the rotating shaft 611, and is configured as a drive roll, as shown in FIG.
Specifically, the auxiliary roll 61 is rotatably supported at its rotating shaft 611 by a support member (not shown) via a bearing 615 . Further, the auxiliary roll 61 rotates by switching between the direction E1 in which the paper 9 is conveyed and the direction E2 opposite to the direction E1 at the time of conveyance by transmitting the power of the electric motor 616 through the power transmission mechanism 617. It's like Here, the direction E1 when the auxiliary roll 61 is conveyed is the direction when the conveyance in the first conveying section 5A partially constituted by the auxiliary roll 61 and the displaced auxiliary roll 63 is used as a reference.

On the other hand, the auxiliary roll 62 is arranged on the side of the transport path of the second transport section 5D away from the transport path of the first transport section 5A (between the second transport section 5D and the double-sided transport section 5F). The auxiliary roll 62 is a roll composed of a rotating shaft and a plurality of roll bodies fixed to the rotating shaft, and is configured as a driven roll.
Specifically, the auxiliary roll 62 is rotatably supported by a supporting member (not shown) through a bearing at its rotating shaft, and is supported so as to be displaceable in directions approaching and separating from the auxiliary roll 61 . It is The bearings of the auxiliary roll 62 are pressed by a pressure spring with a required pressure, so that the roll body is pressed against (the roll body 612 of) the auxiliary roll 61 .

The auxiliary roll 63 is configured to be displaced by a cam mechanism. Specifically, as shown in FIG. 4 and the like, the auxiliary roll 63 is separated from the other auxiliary roll 61 by contact with the moving cam 70A attached to the rotating shaft 611 of the auxiliary roll 61 to be contacted. It is a mechanism that can be displaced like this.

The cam 70A rotates when the auxiliary roll 61 is rotated in the direction E2 opposite to the direction of rotation E1 when the paper 9A is conveyed in the first conveying section 5A, and contacts the rotating shaft 631 of the auxiliary roll 63. A structure configured to stop with the auxiliary roll 63 separated from the other auxiliary rolls 61 is applied.

As shown in FIG. 5, the cam 70A in the first embodiment is driven through a torque limiter 85, which is an example of blocking means for blocking transmission of power when a load exceeding a certain level is applied to the rotating shaft 611 of the auxiliary roll 61. one cam protrusion 72 provided on the base 71; and one stopping protrusion provided at a position away from the cam protrusion 72 of the base 71 in the circumferential direction of the rotating shaft 611. 73.

The base portion 71 is a cylindrical portion having a cavity through which the rotating shaft 611 of the auxiliary roll 61 is passed. As shown in FIG. 4A, the base portion 71 exists in a state of protruding from the peripheral surface of the rotating shaft 611 by a protrusion amount R1. The torque limiter 85 is arranged between the rotating shaft 611 and the base portion 71 . Further, as the torque limiter 85, when the cam protrusion 72 and the stopping protrusion 73 of the cam 70A collide with an abutting portion (80) described later, the load received when the cam 70A is moved from the rotation shaft 611 is applied. A device that cuts off the transmission of power to the base portion 71 and otherwise operates to transmit the power is applied.

Both the cam projecting portion 72 and the stopping projecting portion 73 are portions having shapes projecting along the normal direction from different positions on the peripheral surface of the cylindrical base portion 71 . The cam protrusion 72 can separate (the roll main body 632 of) the auxiliary roll 63 from (the roll main body 612 of) the auxiliary roll 61 by a predetermined distance M when it comes into contact with the rotating shaft 631 of the auxiliary roll 63. It is formed into a shape having a possible projecting length R2.
Further, the cam projecting portion 72 is formed so that the tip portion 72a, which is the portion that contacts the rotating shaft 631 of the auxiliary roll 63 , has an arc-shaped curved surface (semi-cylindrical surface). It should be noted that the stop protrusion 73
is also formed so that its tip end is curved in an arc shape.
Both the cam projection portion 72 and the stop projection portion 73 in the first embodiment are formed by a plate material having a constant width and thickness that rises linearly along the normal line from the base portion 71 and then bends to draw a semicircle. It is formed in such a form that it extends linearly to the base portion 71 along the normal line after being formed.

Also, this cam 70A is used in combination with one abutting portion 80 as a stopper that functions to stop the rotation of the cam 70A.

At this time, when the auxiliary roll 61 to which the cam 70A is attached is rotated in the conveying direction E1 of the sheet 9A, the abutting portion 80 abuts against the cam protruding portion 72 as shown in FIG. 5(a). to stop the rotation of the cam 70A. Further, the abutting portion 80 is such that when the auxiliary roll 61 is rotated in the direction E2 opposite to the direction E1 during transport, the cam protrusion 72 is positioned as the rotational axis of the auxiliary roll 63 as shown in FIG. 5(d). It functions to stop the rotation of the cam 70A when the stopping protrusion 73 abuts against the 631.

The abutting portion 80 in Embodiment 1 is made of a plate-like member, and is, for example, a part of a supporting member (not shown) that supports the auxiliary rolls 61 to 63, or another supporting member that is attached to the supporting member. formed as a part.

As shown in FIG. 5, the cam projecting portion 72, the stopping projecting portion 73, and the abutting portion 80 of the cam 70A are arranged so that the abutting portion 80 exists between the cam projecting portion 72 and the stopping projecting portion 73. Also, as shown in FIG. 5(d), when the cam protrusion 72 contacts the rotary shaft 631 of the auxiliary roll 63 and should be stopped, the stopping protrusion 73 abuts against the abutting portion 80. are arranged as follows.
The cam projecting portion 72 of the cam 70A is configured to abut against the lower end portion 80a of the abutting portion 80 as shown in FIG. 5(a). 5(d), the stop protrusion 73 is configured to abut against one side surface 80c of the abutting portion 80. As shown in FIG.

Further, the conveying device 6A is configured such that the rotation operation of the auxiliary roll 61 (the operation of the electric motor 616) is controlled by the control means 16, as shown in FIG.
The control means 16 comprises arithmetic processing means, storage means, input/output means and the like. An image forming operation request command is input to the control means 16 . The control means 16 may be dedicated to controlling the rotation of the auxiliary roll 61, or may be configured as part of the control means for controlling the overall operation of the image forming apparatus 1. .

In addition, the control unit 16 determines that the length of the sheet 9A supplied from the first container 4A via the first transport unit 5A in the transport direction C during the image forming operation is between the transport roll 53 and the registration roll 51 described above. is connected to an identification means 17 for identifying whether or not the length exceeds the length L1 of the conveying route.
Further, the control means 16 is connected to a drive control section 18 that switches and controls the rotation direction of the electric motor 616 that is the driving source of the auxiliary roll 61 and thus the rotation directions E1 and E2 of the auxiliary roll 61 .

The identifying means 17 obtains and identifies information about the type of paper 9 to be used (length in the conveying direction) included in an image forming operation request command input from the outside of the image forming apparatus 1, for example. configured as Further, the identification unit 17 is not particularly limited, and the input information regarding the type of paper 9 (the length in the conveying direction) input or selected from the input unit of the operation panel (not shown) of the image forming apparatus 1 is used for image formation. Detected information from a means for obtaining and identifying before the start of the operation and a detecting means for detecting the type (length in the conveying direction) of the paper 9 accommodated in the accommodation cassette 41 of the first accommodation section 4A is used for the image forming operation. It may be configured as a means to obtain and identify before starting. Furthermore, the identification means 17 may be a combination of these means.

The control unit 16 is configured to perform the following control when an image forming operation is performed using the paper 9A supplied from the first storage unit 4A via the first transport unit 5A.
That is, when the control means 16 obtains the identification information that the paper 9A is the long size paper 9AL exceeding the length L1 from the identification means 17 before performing the image forming operation, the control means 16 instructs the drive control section 18 to A control signal is sent to rotate the electric motor 616 in the direction opposite to that during transportation. Further, when the identification information indicating that the paper 9A is the short size (small size) paper 9AS having the length L1 or less is obtained from the identification means 17, the control means 16 causes the drive control portion 18 to activate the electric motor 616. Send a control signal to rotate in the direction of transport.

<Operation in the transport device>
The conveying device 6A in the image forming apparatus 1 operates as follows.

In the image forming apparatus 1, when the control means 16 receives the command requesting the image forming operation using the paper 9A supplied from the first storage portion 4A via the first transport portion 5A, the paper 9A is sent from the identification means 17. is a sheet longer than the length L1.

At this time, when the control means 16 obtains the identification information from the identification means 17 that the paper 9A to be conveyed is the paper 9AS having a size shorter than the length L1 (length L1 or less), the drive control section 18 to rotate the electric motor 616 of the auxiliary roll 61 in the transport direction.

As a result, in the conveying device 6A, the auxiliary roll 61 starts to rotate in the conveying direction E1, and the cam 70A attached to the rotating shaft 611 via the torque limiter 85 also starts to rotate following the same direction E1. . After that, as shown in FIG. 5(a), the cam projection 72 of the cam 70A abuts against the abutting portion 80 (the lower end 80a thereof), and the torque limiter 85 prevents the auxiliary roll 61 from rotating from the rotating shaft 611. Power transmission is interrupted and its rotation is stopped.

As a result, in the conveying device 6A, as shown in FIGS. 4A and 5A, the cam protrusion 72 of the cam 70A is not in contact with the rotating shaft 631 of the auxiliary roll 63. The auxiliary roll 63 receives the pressure F1 from the pressing spring 636 and is displaced in the direction D1 approaching the auxiliary roll 61, whereby the auxiliary roll 63 rotates as shown in FIG. 6(a). will come into contact with and take you around.
Therefore, in the transport path of the first transport unit 5A, a pair of transport rolls consisting of auxiliary rolls 61, 63 that rotate in the transport direction exists between the transport roll 53 and the registration roll 51 that are separated by a length L1. will do. Incidentally, at this time, the auxiliary rolls 61 and 62 constituting the second conveying section 5D come into contact with each other and rotate in the direction opposite to the direction during conveyance in the second conveying section 5D. However, at this time, there is no problem because the sheet 9B (9C) is not conveyed via the second conveying section 5D (including the third conveying section 5E).

Therefore, in the conveying device 6A at this time, as shown in FIG. 6A, the sheet 9AS having a size shorter than the length L1 is in contact with the pair of auxiliary rolls 53 following the pair of auxiliary rolls. By being held between 61 and 63 and conveyed so as to be relayed, the sheet is reliably fed until it reaches the registration rolls 51 . As a result, the conveying device 6A can ensure the ability to convey the short-sized (small-sized) sheet 9AS.
In this case, in the image forming section 2, an image is formed satisfactorily on the short-sized paper 9AS that is normally conveyed from the registration rolls 51 of the conveying device 6A.

On the other hand, when the control means 16 obtains the identification information from the identification means 17 that the paper 9A to be conveyed is the long size paper 9AL exceeding the length L1, the control means 16 controls the drive control portion 18 to The electric motor 616 of is rotated in a direction opposite to the direction during transportation.

As a result, in the conveying device 6A, the auxiliary roll 61 begins to rotate in the direction E2 opposite to the direction E1 during transportation, and the cam 70A also begins to rotate in the same direction E2.
At this time, as shown in FIGS. 5(b) and 5(c), the cam projection 72 of the cam 70A contacts the rotating shaft 631 of the auxiliary roll 63 and moves in the direction in which the auxiliary roll 63 is separated from the auxiliary roll 61. Begin pressing to displace to D2. At this time, the cam 70A moves while the tip portion 72a of the cam projecting portion 72 formed of an arc-shaped curved surface comes into contact with the cylindrical rotating shaft 631, so that the operation of displacing the auxiliary roll 63 in the separation direction D2 is smooth. done.
After that, as shown in FIG. 5(d), the cam 70A has its stopping protrusion 73 abut against the abutting portion 80 (one side surface portion 80c), and the torque limiter 85 causes the rotation shaft 611 of the auxiliary roll 61 to rotate. The transmission of power from is interrupted and its rotation is stopped.

As a result, in the conveying device 6A, as shown in FIGS. 4(b) and 5(d), the tip portion 72a of the cam projecting portion 72 of the cam 70A, which has the projecting length R2, does not extend beyond the auxiliary roll 63. Since it stops in contact with the rotating shaft 631, the auxiliary roll 63 is displaced in the direction D2 away from the auxiliary roll 61 against the pressure F1 by the pressure spring 636, and the rotating auxiliary roll 61 is displaced. It will be in a non-contact state separated by a required distance M.
Therefore, in the transport path of the first transport unit 5A, there is no pair of transport rolls in contact between the transport roll 53 and the registration roll 51, which are separated by the length L1.

Therefore, in the conveying device 6A at this time, as shown in FIG. After simply passing through the space between the auxiliary rolls 61 and 63 in the closed state, the sheet is fed to the registration rolls 51. - 特許庁
Therefore, even if the long-sized paper 9AL is conveyed to the registration rolls 51 in an attitude that is inclined with respect to the conveyance direction C, the long-sized paper 9AL that is sent in that inclined attitude is As will be described below, the sheet is conveyed in a normal conveying attitude along the original conveying direction C without being obliquely conveyed from the registration rolls 51 .

That is, in the conveying device 6A at this time, when the long-sized paper 9AL is conveyed to the registration rolls 51 in an oblique posture as illustrated in FIG. As shown in FIG. 7(b), the paper 9AL is stretched between the stopped registration roll 51 and the transport roll 53 during transport from the end 9c on the side that hits the registration roll 51 first to the opposite end 9d. After the sheet is temporarily bent and curved, the sheet starts to be fed from the registration rolls 51 as the registration rolls 51 begin to rotate.
At this time, as illustrated in FIG. 7(c), the sheet 9AL is sent out in a posture in which the front portion, which is the leading end 9a, is substantially parallel to the axial direction B of the rotation shaft 511 of the registration roll 51, while the rear end The rear portion to be 9b is sent in the conveying path between the registration rolls 51 and the conveying rolls 53 while leaving the curved portion 9t.

At this time, in the conveying device 6A, in addition to the fact that the conveying roll 53 is arranged at a position separated from the registration roll 51 by a relatively long length L1, the sheet is conveyed on the conveying path between the conveying roll 53 and the registration roll 51. Due to the absence of a pair of transport rolls (auxiliary rolls 61 and 63) exerting force, the sheet 9AL is strongly held by being sandwiched between the pair of transport rolls in the transport path of length L1. do not become.
For this reason, the curved portion 9t of the paper 9AL tends to shift slightly toward the upstream side in the conveying direction C, including the space between the separated auxiliary rolls 61 and 63, and thus tends to become smaller. The portion 9t that is formed does not strongly push the tip 9a toward the downstream side in the conveying direction C (toward the registration rolls 51).

As described above, the long-sized paper 9AL conveyed in an oblique posture is stably corrected in the conveyance path between the registration rolls 51 and the conveyance rolls 53. Then, as shown in FIG. 7(d), the sheet is conveyed in a normal conveying posture along the original conveying direction C without being obliquely conveyed from the registration rolls 51. As shown in FIG.

In this case, in the image forming section 2, an image is formed on the paper 9AL conveyed from the registration rolls 51 of the conveying device 6A in a normal conveying posture in a good state in which parallelism to the paper is maintained. .

Further, in the conveying device 6A, when subsequently conveying the long size paper 9AL supplied from the first storage unit 4A through the conveying path of the first conveying unit 5A, the auxiliary roll 63 is separated from the auxiliary roll 61. The sheet 9AL is conveyed while continuing the state of the sheet 9AL. On the other hand, when the sheet 9A supplied from the first storage section 4A is not transported thereafter, the auxiliary roll 63 is moved to the auxiliary roll 61 in the same manner as when the short size sheet 9AS is transported from the first storage section 4A. It is designed to be in contact with the

As described above, in the transport device 6A having two transport paths such as the first transport section 5A and the second transport section 5D, the paper 9A merges upstream of the registration roll 51 in the transport direction C. The auxiliary roll 63, which is one of the three auxiliary rolls 61 to 63 arranged between the position J1 and the transport rolls 53 and 56 arranged in the two transport paths, respectively, assists the transport of the paper 9A. is transported from at least one of the two transport paths while ensuring the transportability for the small-sized paper 9AS, compared to the case where the configuration of displacing the is displaced so as to contact and separate from the other auxiliary roll 61. The skew feeding of the registration rolls 51 with respect to the sheet 9A to be processed is suppressed. In other words, it is possible to suppress diagonal feeding of the sheet 9A conveyed from at least one of the two conveying paths by the registration rolls 51 and ensure conveyability of the small-sized sheet 9AS.

Further, in the conveying device 6A, the cam 70A for displacing the auxiliary roll 63 is attached to the rotating shaft 611 of the other auxiliary roll 61, so the cam 70A is not attached to the rotating shaft 611 of the other auxiliary roll 61. As compared with the case, there is no need to additionally provide means for attaching the cam 70A.
Further, in the conveying device 6A, since the cam 70A attached to the rotating shaft 611 of the auxiliary roll 61 is rotated using the driving force of the auxiliary roll 61, the driving force of the auxiliary roll 61 is not used for the cam 70A. There is no need to additionally provide a driving means for driving the cam 70A, as compared with the case of rotating the cam 70A.
Furthermore, in the conveying device 6A, compared to the case where the base portion 71 provided via the torque limiter 85, the cam 70A having the one cam projection portion 72 and the one stop projection portion 73, and the one abutting portion 80 are not applied. , the cam 70A and one abutting portion 80 are arranged in a state of being concentrated around the end of the rotating shaft 611 of at least one auxiliary roll 61. As shown in FIG.

In addition, in the conveying device 6A, the sheet 9B conveyed from the second container 4B to the registration roll 51 via the conveying path of the second conveying unit 5D and the third conveying unit E (second conveying unit) from the third container 4C. The sheet 9C conveyed to the registration rolls 51 via the conveyance path of the section 5D) is conveyed to the registration rolls 51 in the following manner.
In other words, the sheets 9B and 9C at this time are nipped and conveyed by the pair of conveying rolls 56 in common, regardless of the length of the sheets 9B and 9C during conveyance, and then the sheets 9B and 9C shown in FIG. A pair of auxiliary rolls 61 and 62 that are in contact with each other so as to hold the sheet are also pinched and conveyed to the registration rolls 51 .

[Embodiment 2]
FIG. 8 shows part of a transport device according to the second embodiment.
The conveying device 6B according to the second embodiment employs a cam 70B having a different configuration and two abutting portions 81 and 82 as means for displacing the auxiliary roll 63 in the directions D1 and D2 to approach and separate from the auxiliary roll 61. The configuration is the same as that of the conveying device 6A (FIGS. 2 to 4, FIG. 6, etc.) according to the first embodiment except that the configuration is changed.

As shown in FIG. 8, the cam 70B in Embodiment 2 includes a base portion 71 attached to the rotating shaft 611 of the auxiliary roll 61 via a torque limiter 85, and one cam projection portion 72 provided on the base portion 71. It is a cam having a shape with
Here, the base portion 71 and the cam projection portion 72 have the same configurations as those of the base portion 71 and the cam projection portion 72 of the cam 70A in the first embodiment. The torque limiter 85 also has the same configuration as the torque limiter 85 in the first embodiment.

Also, the cam 70B is used in combination with two abutment portions 81 and 82 (a first abutment portion 81 and a second abutment portion 82).
When the auxiliary roll 61 to which the cam 70B is attached is rotated in the direction E1 for transporting the paper 9A in the first transporting portion 5A, the first abutment portion 81 is formed as shown in FIG. 8A. It functions to stop the rotation of the cam 70B when the projecting portion 72 abuts against it. Further, when the auxiliary roll 61 is rotated in the direction E2 opposite to the direction E1 at the time of transportation, the second abutment portion 82 moves the cam protrusion 72 toward the auxiliary roll 63 as shown in FIG. 8(d). It functions to stop the rotation of the cam 70B by contacting the rotary shaft 631 of the cam 70B.

Both of the two abutment portions 81 and 82 in the second embodiment are made of plate-like members, for example, supported by the auxiliary rolls 61 to 63, as in the case of the one abutment portion 80 in the first embodiment. It is formed as part of a support member (not shown) attached to the support member or as part of another support member attached to the support member.

The cam projection 72 and the two abutting portions 81 and 82 of the cam 70B are arranged such that the cam projection 72 is located between the first abutting portion 81 and the second abutting portion 82 as shown in FIG. Also, as shown in FIG. 8(d), when the cam protrusion 72 contacts the rotating shaft 631 of the auxiliary roll 63 and should be stopped, the cam protrusion 72 is positioned at the second abutting portion It is arranged so as to abut against 82 .
The cam projecting portion 72 of this cam 70B abuts against the lower end portion 81a of the first abutting portion 81 as shown in FIG. It is configured to abut against the upper end 82b of the portion 82. As shown in FIG.

<Operation in the transport device>
The conveying device 6B having the cam 70B and the two abutting portions 81 and 82 operates as follows.

In the image forming apparatus 1 provided with the conveying device 6B, when the control means 16 receives a command requesting an image forming operation using the sheet 9A supplied from the first storage section 4A via the first conveying section 5A, an identification Information is obtained from the means 17 as to whether or not the paper 9A has a length exceeding the length L1.

At this time, when the control means 16 obtains the identification information from the identification means 17 that the paper 9A to be transported is the paper 9AS having a size shorter than the length L1, the control means 16 controls the transport device 6A according to the first embodiment. Similarly to the case, the drive control unit 18 is controlled to rotate the electric motor 616 of the auxiliary roll 61 in the transport direction.

As a result, in the conveying device 6B, the auxiliary roll 61 begins to rotate in the direction E1 during conveyance in the first conveying section 5A, and the cam 70B attached to the rotating shaft 611 via the torque limiter 85 follows the same direction E1. to start rotating. Thereafter, as shown in FIG. 8(a), the cam projection 72 of the cam 70B abuts against the first abutting portion 81 (the lower end portion 81a thereof), and the torque limiter 85 causes the rotary shaft of the auxiliary roll 61 to move. Power transmission from 611 is interrupted and its rotation is stopped.

As a result, in the conveying device 6B, as shown in FIGS. 4A and 8A, the cam protrusion 72 of the cam 70B is not in contact with the rotating shaft 631 of the auxiliary roll 63. The auxiliary roll 63 is displaced in the direction D1 in which the auxiliary roll 63 approaches the auxiliary roll 61 and comes into contact with and rotates with the rotating auxiliary roll 61 .

Therefore, in the conveying device 6B at this time as well, as shown in FIG. 6A, the sheet 9AS having a size shorter than the length L1 is in contact with the pair of the conveying rolls 53 and the pair of auxiliary rollers 53, as shown in FIG. By being nipped and conveyed by the rolls 61 and 63, it is conveyed to the register roll 51, and as in the case of the conveying device 6A according to the first embodiment, the short-sized (small-sized) sheet 9AS is conveyed. ensured.

On the other hand, when the control means 16 obtains the identification information from the identification means 17 that the paper 9A to be conveyed is the long size paper 9AL exceeding the length L1, in the case of the conveying device 6A according to the first embodiment, Similarly, the drive control unit 18 is controlled to rotate the electric motor 616 of the auxiliary roll 61 in the opposite direction to the transport direction.
As a result, in the conveying device 6B, the auxiliary roll 61 begins to rotate in the direction E2 opposite to the direction E1 during transportation, and the cam 70B also begins to rotate in the same direction E2.

At this time, as shown in FIGS. 8(b) and 8(c), the cam projection 72 of the cam 70B comes into contact with the rotary shaft 631 of the auxiliary roll 63, separating the auxiliary roll 63 from the auxiliary roll 61. Start pushing to displace in direction D2.
Thereafter, as shown in FIG. 8(d), the cam projection 72 of the cam 70B abuts against the second abutting portion 82 (upper end 82b), and the torque limiter 85 causes the rotating shaft 611 of the auxiliary roll 61 to move. The transmission of power from is interrupted and its rotation is stopped.

As a result, in the conveying device 6B, as shown in FIGS. 4(b) and 8(d), the tip portion 72a of the cam projecting portion 72 of the cam 70B, which has the projecting length R2, does not extend beyond the auxiliary roll 63. Since it stops in contact with the rotating shaft 631, the auxiliary roll 63 is displaced in the direction D2 away from the auxiliary roll 61 and is in a non-contact state away from the rotating auxiliary roll 61 by the distance M.
Therefore, in the transport path of the first transport unit 5A, there is no pair of transport rolls in contact between the transport roll 53 and the registration roll 51 separated by the length L1.

Therefore, in the conveying device 6B at this time, as shown in FIG. 6A, the long size paper 9AL exceeding the length L1 follows the pair of conveying rolls 53 and the auxiliary rolls 61 and 63 which are separated from each other. After passing between, it is sent to the register roll 51.
Therefore, even if the long-sized paper 9AL is conveyed to the registration rolls 51 in an attitude that is inclined with respect to the conveyance direction C, the long-sized paper 9AL that is sent in that inclined attitude is Since it is not sandwiched and held by the auxiliary rolls 61 and 63 between the registration roll 51 and the transport roll 53, it is not obliquely fed from the registration roll 51 as in the case of the transport device 6A according to the first embodiment. The sheet is sent in a normal conveying posture along the original conveying direction C without any movement.

[Embodiment 3]
FIG. 9 shows the configuration of a conveying device according to the third embodiment.
The conveying device 6C according to Embodiment 3 additionally includes an auxiliary roll 64 arranged in the conveying path of the double-sided conveying section 5F, and adds a configuration in which the auxiliary roll 62 is displaced in a direction toward and away from the auxiliary roll 64. The configuration is the same as that of the carrier devices 6A and 6B according to the first and second embodiments, except that the configuration is changed.

As shown in FIG. 9, the conveying device 6C is similar to the image forming apparatus 1 in the first embodiment and the like, with the registration rollers 51, the three first conveying units 5A, the second conveying unit 5D (and the third conveying unit 5E). ) and double-sided transport section 5F, transport rolls 53, 56, and 58e that transport paper 9 toward registration rolls 51 in first transport section 5A, second transport section 5D, and double-sided transport section 5F, respectively, and first transport Positions J1 and J3 where the respective transport paths (three transport paths) in the section 5A, the second transport section 5D and the double-sided transport section 5F merge and the transport rolls 53, 56 and 58e in the respective transport paths. , and has four auxiliary rolls 61, 62, 63, 64 for assisting the transport of the paper 9 on each transport path. Among these, the pair of transport rolls 58e is an example of a pair of second rolls.

In addition, as shown in FIGS. 3 and 10, the conveying device 6C has four auxiliary rolls 61 to 64, two of which are the auxiliary rolls 63 and 62. Displaced away from the auxiliary roll 61 or 64 as another auxiliary roll when conveying the paper 9A, 9B, 9C, 9R longer than the distance L1 between any one of them, and the registration roll 51 and the transport roll It is displaced so as to come into contact with the auxiliary roll 61 or 64 when conveying the paper 9A, 9B, 9C, 9R shorter than the distance L1 between any one of 53, 56, 58e. Here, the paper 9R indicates the paper when it is conveyed through the double-sided conveying section 5F, and is actually one of the papers 9A, 9B, and 9C.

As for the transport rolls 56 and 58e other than the transport roll 53 in the transport device 6C, the length L1 of the transport path between the transport roll 51 and the registration roll 51 is set to the diagonal feed of the registration roll 51 as in the case of the transport roll 53 in the first embodiment. It is set to a value that allows the shortest sheet 9 among the sheets 9 having the length in the transport direction C in which the occurrence of the occurrence of the shortest is likely to occur. Incidentally, the transport roll 58e in the double-sided transport section 5F has a length (distance) away from the registration roll 51, which is longer than the transport roll 58d in the first embodiment (L1).

As shown in FIGS. 9 and 10, the four auxiliary rolls 61 to 64 in the conveying device 6C are arranged in the respective conveying paths of the second conveying section 5D and the double-sided conveying section 5F. placed in a fixed position. In addition, the remaining auxiliary rolls 63 can be displaced in directions approaching and separating from the auxiliary rolls 61 while forming a part of the conveying path of the first conveying section 5A in the same manner as in the first embodiment. placed in good condition. Further, the remaining auxiliary rolls 62 can be displaced toward and away from the auxiliary rolls 61 or 64 while forming part of the conveying paths of the second conveying section 5D and the double-sided conveying section 5F, respectively. placed in good condition.

Of these, the auxiliary rolls 61, 62, and 64 are positioned between the position J2 or J3 where the respective transport paths of the second transport section 5D or the double-sided transport section 5F merge and the transport roll 53. It is arranged at a position capable of assisting the conveyance of the sheets 9B, 9C, and 9R whose length during conveyance is shorter than the length L1 of the conveyance path between 58e and the registration roll 51. FIG.

Further, the auxiliary roll 62 is arranged so as to be present and displaced between the transport path of the second transport section 5D and the transport path of the double-sided transport section 5F. As shown in FIGS. 10 and 11, the auxiliary roll 62 is a roll composed of a rotating shaft 621 and a plurality of roll bodies 622 fixed to the rotating shaft 621, and is configured as a driven roll.
Specifically, the auxiliary roll 62 has its rotating shaft 621 rotatably supported by a support member (not shown) via a bearing 625, and rotates in a direction D3 toward and away from the auxiliary roll 64 in a direction D3 and a direction D4 away from the auxiliary roll 64. Displaceably supported. At the same time, when viewed from the relationship with the auxiliary roll 61, this displaceable support is displaceably supported in a direction D4 toward and away from the auxiliary roll 61 as shown in FIG. will also become Further, as shown in FIG. 11, the auxiliary roll 62 has its bearing 625 pushed by a pressure spring 626 with a required pressure F1. is pressed with the required contact pressure.

Further, the auxiliary roll 64 is arranged on the opposite side of the conveying path of the second conveying section 5D in the conveying path of the double-sided conveying section 5F (outside the conveying path adjacent to the double-sided conveying section 5F). As shown in FIG. 11, the auxiliary roll 64 is a roll composed of a rotating shaft 641 and a plurality of roll bodies 642 fixed to the rotating shaft 641, and is configured as a drive roll.
Specifically, as shown in FIG. 11, the auxiliary roll 64 is rotatably supported by a supporting member (not shown) through a bearing 645 at its rotating shaft 641 . Further, the power of the electric motor 646 is transmitted to the auxiliary roll 64 via the power transmission mechanism 647, so that, as shown in FIG. The direction E3 is switched to the opposite direction E4 to rotate.

As with the auxiliary rolls 63 in the first and second embodiments, the auxiliary rolls 62 are configured to be displaced by a cam mechanism.
Specifically, as shown in FIG. 11(b), the auxiliary roll 62 is attached to a rotating shaft 641 of the auxiliary roll 64 as a drive roll, and the moving cam 70A or 70B is displaceable. By contacting the shaft 621, it is displaced away from the other auxiliary rolls 64 as shown in FIG. 12(a). Also, as shown in FIG. 11(a), the auxiliary roll 62 moves away from the rotating shaft 621 of the auxiliary roll 62 whose cam 70A or 70B is displaceable, as shown in FIG. 12(b). It is designed to be displaced so as to come into contact with another auxiliary roll 64 .

As the cam 70A or 70B attached to the rotating shaft 641 of the auxiliary roll 64, one having substantially the same configuration as the cam 70A (FIG. 5) or 70B (FIG. 8) described in the first and second embodiments is applied.
At this time, when the cam 70A is applied, it is used in combination with one abutting portion 80 (FIG. 5), almost like the case of the cam 70A in the first embodiment.
Also, when the cam 70B is applied, it is used in combination with the two abutting portions 81 and 82 (FIG. 8), in substantially the same manner as the cam 70B in the second embodiment.

Further, as shown in FIG. 9, in the conveying device 6C, as in the case of the conveying device 6A in the first embodiment, the rotation operations of the auxiliary rolls 61 and 64 (the operations of the electric motors 616 and 646) are controlled by the control means. It is configured to be controlled by 16.

The identification means 17 is connected to the control means 16 as in the case of the conveying device 6A in the first embodiment.
At this time, the identifying means 17 determines that the length of the sheet 9A supplied from the first container 4A through the conveying path of the first conveying unit 5A in the conveying direction C during the image forming operation is the above-described conveying roll 53 and the registration roll. In addition to identifying whether or not the length exceeds the length L1 of the conveying route between 51 and 51, the following identification is performed.
That is, the length of the sheet 9B or 9C in the transport direction C supplied from the second storage section 4B or the third storage section 4C via the transport path of the second transport section 5D or the third transport section 5E, respectively, is the length described above. It is possible to identify whether or not the length exceeds the length L1 of the transport path between the transport roll 56 and the registration roll 51, and the transport direction C of the paper 9R re-fed via the transport path of the double-sided transport section 5F. is longer than the above length L1.

Further, the drive control section 18 is connected to the control means 16 as shown in FIG.
At this time, the drive control unit 18 switches and controls the rotation direction of the electric motor 616 which is the drive source of the auxiliary roll 61 and thus the rotation directions E1 and E2 of the auxiliary roll 61. Control is performed by switching the rotation direction of an electric motor 646 and thus the rotation directions E3 and E4 of the auxiliary rolls 64 .

<Operation of Conveyor>
This transport device 6C operates as follows.

In the image forming apparatus 1 having the conveying device 6C, when the control means 16 receives the command requesting the image forming operation using the sheet 9A supplied from the first storage section 4A via the first conveying section 5A, the identification means 17 to obtain information as to whether or not the sheet 9A has a length exceeding the length L1, and operates in the same manner as the conveying devices 6A and 6B according to the first and second embodiments.

Further, in the image forming apparatus 1, the control unit 16 controls the sheet supplied from the second container 4B or the third container 4C via the transport path of either the second transport unit 5D or the third transport unit 5E. When receiving a command requesting an image forming operation using the sheets 9B and 9C, information is obtained from the identification means 17 as to whether or not the sheets 9B and 9C have a length exceeding the length L1.

At this time, when the control means 16 obtains identification information from the identification means 17 that the sheets 9B and 9C to be conveyed are the sheets 9BS and 9CS having a size shorter than the length L1, the control means 16 controls the drive control section 18. Then, the electric motor 646 of the auxiliary roll 64 is rotated in the direction opposite to the direction during the transfer in the double-sided transfer portion 5F.

As a result, in the conveying device 6C, the auxiliary roll 64 begins to rotate in the direction E4 opposite to the direction E3 during conveyance in the double-sided conveying section 5F, and the cam 70A or the cam 70A attached to the rotating shaft 641 via the torque limiter 85 70B also begins to rotate following the same direction E4. After that, the cam 70A or 70B, as can be understood with reference to FIGS. The torque limiter 85 cuts off the transmission of power from the rotation shaft 641 of the auxiliary roll 64 to stop its rotation.

As a result, in the conveying device 6C, as shown in FIG. 11(b), the cam protrusion 72 of the cam 70A or the cam 70B comes into contact with and presses the rotating shaft 621 of the auxiliary roll 62. As a result, as shown in FIG. 12(a), the auxiliary roll 62 is separated from the auxiliary roll 64 and displaced in the direction D4 in contact with the auxiliary roll 61, and the auxiliary roll 62 contacts the rotating auxiliary roll 61. and become accompaniment.
At this time, the auxiliary roll 61 is controlled to rotate in a direction E2 opposite to the direction E1 during transport in the first transport portion 5A (this is the direction during transport in the second transport portion 5D).

Therefore, in the conveying device 6C at this time, as shown in FIG. 12A, the sheets 9BS and 9CS having a size shorter than the length L1 are fed to the second conveying section 5D (including the third conveying section 5E). Following the pair of transport rolls 56 on the transport path, the sheet is transported to the registration rolls 51 by being sandwiched between and transported by a pair of auxiliary rolls 61 and 62 in contact with each other. As a result, in the transport device 6C, as in the case of the transport device 6A according to the first embodiment, the transportability for the short size (small size) sheets 9BS and 9CS is ensured.

The conveying device 6C also operates in the same manner when it receives identification information from the identifying means 17 that the sheet 9R to be conveyed in the double-sided conveying section 5F is the long-sized sheet 9RL exceeding the length L1. is configured as follows. That is, in the conveying device 6C at this time as well, the auxiliary roll 62 is separated from the auxiliary roll 64 as shown in FIG. 12(a).

As a result, in the conveying device 6C at this time, the sheet 9RL having a long size exceeding the length L1 follows the pair of conveying rolls 58e in the conveying path of the double-sided conveying section 5F, and then the auxiliary rolls 62 and 64, which are separated from each other. After passing through the space between them, it is sent to the register rolls 51.例文帳に追加
Therefore, even if the long-sized paper 9RL is transported to the registration rolls 51 in an oblique posture with respect to the transport direction C in the transport path of the double-sided transport portion 5F, The long-sized paper 9RL to be fed is not sandwiched and held by the auxiliary rolls 62 and 64 between the registration roll 51 and the transport roll 58e even in the transport path of the double-sided transport section 5F. As in the case of the conveying device 6A, the sheet is conveyed in a normal conveying posture along the original conveying direction C without being obliquely conveyed from the registration rolls 51 .

On the other hand, when the control means 16 obtains the identification information from the identification means 17 that the sheets 9B and 9C to be conveyed are the long size sheets 9BL and 9CL exceeding the length L1, the control means 16 controls the drive control section 18. to rotate the electric motor 646 of the auxiliary roll 64 in the direction of the transport in the double-sided transport section 5F.

As a result, in the conveying device 6C, the auxiliary roll 64 begins to rotate in the conveying direction E3, and the cam 70A or 70B attached to the rotating shaft 641 via the torque limiter 85 also rotates in the same direction E3. Begin to. After that, as can be understood with reference to FIGS. 5(a) and 8(a), the cam projection 72 of the cam 70A or 70B abuts against the abutting portion 80 or 81 and the torque limiter 85 causes the auxiliary roll to move. The transmission of power from the rotating shaft 641 of 64 is interrupted, and its rotation is stopped.

As a result, in the conveying device 6C, as shown in FIG. 11(a), the cam protrusion 72 of the cam 70A or the cam 70B is not in contact with the rotating shaft 621 of the auxiliary roll 62. 10(b) and 12(b), the auxiliary roll 62 is separated from the auxiliary roll 61 and displaced in the direction D3 in contact with the auxiliary roll 64, and the auxiliary roll 62 rotates. It comes into contact with 64 and rotates with it.
At this time, as shown in FIG. 12B, the auxiliary roll 61 moves in the direction E1 during transport in the first transport section 5A (this is the direction during transport when the transport in the second transport section 5D is used as a reference). E2 is controlled to rotate in the opposite direction). However, in this case, even if the auxiliary roll 61 is controlled to rotate in the direction E2 opposite to the direction in which the paper 9A is conveyed in the first conveying portion 5A, the sheet 9A is not conveyed in the first conveying portion 5A. Therefore, there is no problem.

Therefore, in the conveying device 6C at this time, as shown in FIG. 12B, the long size sheets 9BL and 9CL exceeding the length L1 are transferred to the second conveying section 5D (including the third conveying section 5E). After passing between the auxiliary rolls 61 and 62 which are separated from each other following the pair of conveying rolls 56 on the conveying path, the sheet is sent to the registration rolls 51 .
Therefore, the long-sized sheets 9BL and 9CL may be transported to the registration rollers 51 in a posture inclined with respect to the transport direction C in the transport path of the second transport unit 5D (including the third transport unit 5E). Even if there is, the long sheets of paper 9BL and 9CL sent in the oblique posture are not sandwiched and held by the auxiliary rolls 61 and 62 between the registration roll 51 and the transport roll 56. As in the case of the conveying device 6A according to the first embodiment, the sheet is conveyed in a normal conveying posture along the original conveying direction C without being obliquely conveyed from the registration rolls 51 .

The conveying device 6C also operates in the same manner when it receives identification information from the identification means 17 that the sheet 9R to be conveyed in the double-sided conveying section 5F is the sheet 9RS having a size shorter than the length L1. is configured as follows. Therefore, in the conveying device 6C at this time as well, the auxiliary roll 62 is kept in contact with the auxiliary roll 61 as shown in FIG. 12(b).

As a result, in the conveying device 6C at this time, the sheet 9RS having a size shorter than the length L1 is transferred from the auxiliary rolls 62 and 64 in contact with the pair of conveying rolls 58e in the conveying path of the double-sided conveying section 5F. Since the sheet is nipped and conveyed by the pair of conveying rolls, it is conveyed to the registration rolls 51, so that the short size (small size) sheet 9RS can be conveyed even in the conveying path of the double-sided conveying section 5F.

As described above, the conveying device 6C suppresses the diagonal feeding of the registration rolls 51 with respect to the sheets 9A, 9B, 9C, and 9R conveyed from all the three conveying paths, and the small-sized sheets 9AS, 9BS, 9CS, 9AS, 9BS, 9CS, and 9AS. It is compatible with ensuring transportability for 9RS.
The effect of compatibility in the conveying device 6C is that in a conveying device having three conveying paths in the first conveying section 5A, the second conveying section 5D (including the third conveying section 5E), and the double-sided conveying section 5F, the registration rolls 51 4 which is arranged between the merging position J1 or J3 on the upstream side of the paper 9A in the conveying direction C and the conveying rolls 53, 56, and 58e arranged in the three conveying paths, respectively, to assist the conveying of the paper 9A. This provides an advantageous effect compared to the case where the configuration of displacing the two auxiliary rolls 63 and 62 out of the four auxiliary rolls 61 to 64 so as to contact and separate from the other auxiliary rolls 61 and 64 is not employed.
In particular, in the transport device 6C, even in the inner transport path, which is the transport path of the second transport section 5D (including the third transport section 5E) among the three transport paths, the registration rolls 51 are diagonally fed with respect to the sheets 9B and 9C. It is possible to achieve both the suppression of .

Further, in the transporting device 6C, as auxiliary rolls, the first transporting section 5A, the second transporting section 5D (including the third transporting section 5E), and the double-sided transporting section 5F for transporting the sheet 9 toward the registration rolls 51, respectively. Only auxiliary rolls 61 to 64, which are one more than the total number of paths (three) (four), are arranged.
For this reason, according to the conveying device 6C, compared to the case where a pair of auxiliary rolls are arranged on all of the three conveying paths (in this case, the total number is 2 rolls x 3 conveying paths = 6), Consists of a small total number of auxiliary rolls.

[Other embodiments]
In the first to third embodiments, the conveying devices 6A to 6C provided with two or three conveying paths that merge on the upstream side in the conveying direction C of the registration rolls 51 are exemplified as conveying devices. The transport apparatus of the present invention can also be configured as a transport apparatus having four or more transport paths, if it can be secured.

Further, in Embodiments 1 to 3, a configuration example in which a cam mechanism is applied as means for displacing the auxiliary rolls has been shown, but means other than the cam mechanism can be employed as means for displacing the auxiliary rolls. Incidentally, the cam mechanism is an advantageous means in that it is easy to avoid an increase in cost and power consumption, for example.

Further, in Embodiments 1 to 3, the image forming apparatus 1 is an image forming apparatus that forms a monochromatic image composed of a developer, but the present invention is applicable to an image forming apparatus that forms a color (multicolor) image. can also be applied.
In addition, the image forming apparatus of the present invention is not limited to the image forming apparatus 1 provided with the image forming unit 2 for forming a toner image made of developer, and may be made of other material such as ink. It may be an image forming apparatus having an image forming unit that forms an image.

1 image forming apparatus 2 image forming units 5A to 5F conveying unit (an example of a conveying route)
6A, 6B, 6C Conveying device 9 Paper (an example of a recording medium)
9a... tip 51... register roll (an example of the first roll)
53, 56, 58e... Conveying roll (an example of the second roll)
61, 64 Auxiliary rolls (an example of other auxiliary rolls)
62, 63 Auxiliary rolls (an example of displaceable auxiliary rolls)
70A, 70B Cam 71 Base portion 72 Cam projecting portion 72a Tip portion (portion in contact with rotating shaft)
73 Stop projection 80 Abutting portion 81 First abutting portion 82 Second abutting portion 85 Torque limiter (an example of a blocking means)
611, 641 Rotation shafts to which the cams are attached 631, 621 Rotation shafts C with which the cam protrusions contact Conveyance directions J1, J2, J3 Merging position L1 Length (distance)

Claims (7)

a pair of first rolls for sending the recording medium to be conveyed after the leading end thereof abuts;
a plurality of transport paths arranged to join at a position upstream of the first roll in the transport direction of the recording medium and having a passage space through which the recording medium passes so as to be transported toward the first roll;
A pair of rollers disposed at positions separated from the first roll of the plurality of transport paths on the upstream side in the transport direction beyond the merging position, and transporting the recording medium toward the first roll on each transport path. a second roll;
a plurality of auxiliary rolls arranged at a position between the joining position of the plurality of transport paths and the second roll to assist transport of the recording medium;
with
At least one auxiliary roll among the plurality of auxiliary rolls is displaced away from other auxiliary rolls when conveying a recording medium longer than the distance between the first roll and the second roll, and configured to be displaced so as to come into contact with another auxiliary roll when conveying a recording medium shorter than the distance between the roll and the second roll,
The at least one auxiliary roll is configured to be displaced away from the other auxiliary roll by coming into contact with a moving cam attached to the rotating shaft of the other auxiliary roll to be brought into contact,
The cam includes a base portion attached via a blocking means for blocking transmission of power when a load exceeding a certain level is applied to the rotating shaft of the other auxiliary roll to be brought into contact, and one cam projection provided on the base portion. and one stopping protrusion provided at a position spaced apart from the cam protrusion of the base in the circumferential direction of the rotating shaft,
When the other auxiliary roll is rotated in the conveying direction of the recording medium, the cam projection portion of the cam collides with the cam to stop the rotation of the cam, and the other auxiliary roll is rotated in the conveying direction. When the cam is rotated in the opposite direction, the stopping projection of the cam collides with the rotating shaft of the at least one auxiliary roll to stop the rotation of the cam. Equipped with a contact part,
The cam rotates when the other auxiliary roll to be brought into contact is rotated in a direction opposite to the direction in which the recording medium is conveyed, and the cam protrusion contacts the rotating shaft of the at least one auxiliary roll. A conveying device that stops the at least one auxiliary roll in a state where the protrusion for stopping collides with the protrusion for stopping and separates the at least one auxiliary roll from the other auxiliary roll . a pair of first rolls for sending the recording medium to be conveyed after the leading end thereof abuts;
a plurality of transport paths arranged to join at a position upstream of the first roll in the transport direction of the recording medium and having a passage space through which the recording medium passes so as to be transported toward the first roll;
A pair of rollers disposed at positions separated from the first roll of the plurality of transport paths on the upstream side in the transport direction beyond the merging position, and transporting the recording medium toward the first roll on each transport path. a second roll;
a plurality of auxiliary rolls arranged at a position between the joining position of the plurality of transport paths and the second roll to assist transport of the recording medium;
with
At least one auxiliary roll among the plurality of auxiliary rolls is displaced away from other auxiliary rolls when conveying a recording medium longer than the distance between the first roll and the second roll, and configured to be displaced so as to come into contact with another auxiliary roll when conveying a recording medium shorter than the distance between the roll and the second roll,
The at least one auxiliary roll is configured to be displaced away from the other auxiliary roll by coming into contact with a moving cam attached to the rotating shaft of the other auxiliary roll to be brought into contact,
The cam includes a base portion attached via a blocking means for blocking transmission of power when a load exceeding a certain level is applied to the rotating shaft of the other auxiliary roll to be brought into contact, and one cam projection provided on the base portion. and
a first abutting portion that stops the rotation of the cam by abutting the cam projection portion of the cam when the other auxiliary roll is rotated in the direction of conveying the recording medium; and the other auxiliary roll. A second abutment for stopping the rotation of the cam by abutting the cam projection portion of the cam in contact with the rotating shaft of the at least one auxiliary roll when the cam is rotated in the direction opposite to the conveying direction. and
The cam rotates when the other auxiliary roll to be brought into contact is rotated in a direction opposite to the direction in which the recording medium is conveyed, and the cam protrusion contacts the rotating shaft of the at least one auxiliary roll. A conveying device that abuts on the second abutment portion and stops the at least one auxiliary roll in a state of being separated from the other auxiliary roll . 3. The conveying device according to claim 1 , wherein the cam projecting portion of the cam has an arc-shaped curved surface at least at a portion that contacts the rotating shaft of the at least one auxiliary roll . The at least one auxiliary roll is an outer auxiliary roll arranged outside an outer conveying route in which adjacent conveying routes of the plurality of conveying routes become one, and the outer conveying route
4. A conveying device according to any one of claims 1 to 3, displaced so as to come into contact with and separate from other auxiliary rolls in the path . The at least one auxiliary roll is an inner auxiliary roll arranged between adjacent conveying paths among the plurality of conveying paths, and is in contact with and separated from other auxiliary rolls in both of the adjacent conveying paths. 4. The conveying device according to any one of claims 1 to 3, wherein the conveying device is displaced in the following manner . Among the plurality of auxiliary rolls, at least one of the outer auxiliary rolls arranged outside the outer conveying route in which the adjacent conveying routes in the plurality of conveying routes become one is the other auxiliary roll in the outer conveying route. Displaced to contact and separate from the roll,
In addition, an inner auxiliary roll arranged between adjacent conveying paths in the plurality of conveying paths among the plurality of auxiliary rolls is in contact with and separated from other auxiliary rolls in both of the adjacent conveying paths. 4. A conveying device according to any one of claims 1 to 3, wherein the conveying device is displaceable. an image forming unit that forms an image on a recording medium;
a conveying device that conveys a recording medium conveyed from a plurality of conveying paths to the image forming unit through a pair of first rolls that are conveyed after the leading ends thereof collide;
with
An image forming apparatus, wherein the conveying device includes the conveying device according to any one of claims 1 to 6 .

Images