Medium Transport Device and Recording Device

The present application is based on, and claims priority from JP Application Serial Number 2024-073505, filed Apr. 30, 2024, the disclosure of which is hereby incorporated by reference herein in its entirety.

The present disclosure relates to a medium transport device and a recording device.

An example of this type of device is the recording device described in JP-A-2016-182716. JP-A-2016-182716 describes the following.

A pair of transport rollers and a pair of paper feed rollers constitute a transport section that transports the cut paper CP or the roll paper RP.

In order to transport the medium, it is preferable that the pair of transport rollers and the pair of paper feed rollers are a pair of continuous rollers extending in the width direction. However, since the cost is high and it is not easy to obtain parallelism of one roller with respect to another roller, the other roller is usually constituted by a plurality of rollers.

However, in such a configuration, there is a difference in the transport force applied to the medium between nip portions by both rollers and non-nip portions. Specifically, because there is no nipping between the driven rollers, the non-nip path of the medium is raised more than the nip path, creating a difference between a raised portion and a non-raised portion, making wrinkles more likely to occur.

In particular, when the medium has a three-dimensional structure formed by weaving or knitting threads, like fabric, the difference in paths having a nip of the driven rollers and paths without a nip, that is, the existence of the nip paths and the non-nip paths, makes it easy for expansion and contraction and deformation to occur, and wrinkles are likely to occur. There is room for improvement in terms of such wrinkle generation.

In order to solve the above problems, a medium transport device according to an aspect of the disclosure includes a pair of transport rollers including a main roller configured to apply a feeding force in the transport direction to the medium and a plurality of sub-rollers disposed at intervals along the longitudinal direction of the main roller, and being driven to rotate about a first shaft in a state where the medium is nipped between the sub-rollers and the main roller and an adjustment section configured to adjust a path difference between a first path and a second path, assuming that the first path is a path of the medium nipped and transported between the main roller and the plurality of sub-rollers and the second path is a path of the medium transported in contact with the main roller but not in contact with the plurality of sub-rollers.

A recording device according to an aspect of the disclosure includes a recording section that records on a medium, and a medium transport device that transports the medium toward the recording section, wherein the medium transport device includes a main roller configured to apply a feeding force to the medium in the transport direction, and the pair of transport rollers includes a plurality of sub-rollers disposed at intervals along the longitudinal direction of the main roller, and being driven to rotate about a first shaft in a state where the medium is nipped between the sub-rollers and the main roller, and an adjustment section configured to adjust a path difference between a first path and a second path, assuming that the first path is a path of the medium nipped and transported between the main roller and the plurality of sub-rollers and the second path is a path of the medium transported in contact with the main roller but not in contact with the plurality of sub-rollers.

The present disclosure will first be schematically described below.

A medium transport device according to a first aspect of the includes a pair of transport rollers including a main roller configured to apply a feeding force in the transport direction to the medium and a plurality of sub-rollers disposed at intervals along the longitudinal direction of the main roller, and being driven to rotate about a first shaft in a state where the medium is nipped between the sub-rollers and the main roller, and an adjustment section configured to adjust a path difference between a first path and a second path, assuming that the first path is a path of the medium nipped and transported between the main roller and the plurality of sub-rollers and the second path is a path of the medium transported in contact with the main roller but not in contact with the plurality of sub-rollers.

Here, “adjusting a path difference” in “an adjustment section that adjusts a path difference between the first path and the second path” means applying a force in a direction in which a portion of the medium positioned in the first path and a portion of the medium positioned in the second path relatively closer each other in an intersecting direction that intersects the transport direction.

According to this aspect, the device is provided with an adjustment section for adjusting a path difference between the first path, which is a path nipped between the main roller and the plurality of sub-rollers and transported, and the second path, which is a path in contact with the main roller but not in contact with the plurality of sub-rollers and transported. By the adjustment section, it is possible to suppress the occurrence of wrinkles in the medium which is likely to occur due to the presence of the first path and the second path.

A medium transport device according to a second aspect of the disclosure is an aspect according to the first aspect, the first shaft of the sub-rollers is disposed so as to be shifted in the transport direction with respect to the rotating shaft of the main roller. In the pair of transport rollers having a structure in which the first shaft of the sub-roller is disposed so as to be shifted in the transport direction with respect to the rotating shaft of the main roller, the path difference is likely to be large, and thus the wrinkle is likely to be generated.

However, according to this aspect, the occurrence of wrinkles in the medium based on the path difference can be suppressed by the adjustment section. In other words, when the pair of transport rollers has such a structure, the effect obtained is remarkable.

A medium transport device according to a third aspect of the disclosure is an aspect according to the first aspect, the adjustment section is a pressing section that is disposed at a position downstream of the sub-roller in the transport direction and that presses the medium from a sub-roller side and the pressing section is disposed at a position overlapping a portion between the plurality of sub-rollers in the longitudinal direction and presses the medium in the second path.

According to this aspect, the pressing section that is disposed at a position downstream of the sub-roller in the transport direction and presses the medium from the sub-roller side. Further, the pressing section that is disposed at a position overlapping with the portion between the plurality of sub-rollers in the longitudinal direction and presses the medium in the second path. With this configuration, by using the pressing section, it is possible to realize the adjustment section by simplifying the structure, thereby it is possible to suppress the generation of wrinkles in the medium.

A medium transport device according to a fourth aspect of the disclosure is an aspect according to the first aspect, the adjustment section is a suction section that is disposed at a position downstream of the sub-roller in the transport direction and that suctions the medium from a main roller side and the suction section is disposed at a position overlapping with a portion between the plurality of sub-rollers in the longitudinal direction and sucks the medium in the second path.

According to this aspect, a suction section that is disposed at a position downstream of the sub-roller in the transport direction and suctions the medium from the main roller side, Further, the suction section that is disposed at a position overlapping with the portion between the sub-rollers in the longitudinal direction, and sucks the medium in the second path. With this configuration, even by using the suction section instead of the pressing section, it is possible to realize the adjustment section by simplifying the structure, thereby it is possible to suppress the generation of wrinkles in the medium.

A medium transport device according to a fifth aspect of the disclosure is an aspect according to the first aspect, the adjustment section is a pressing section that is disposed at a position downstream of the sub-roller in the transport direction and that presses the medium from the main roller side and the pressing section is disposed at a position overlapping the plurality of sub-rollers in the longitudinal direction and that presses the medium in the first path.

According to this aspect, a pressing section that is disposed at a position downstream of the sub-roller in the transport direction and presses the medium from the main roller side, Further, the pressing section that is disposed at a position overlapping the plurality of sub-rollers in the longitudinal direction and presses the medium in the first path. With this configuration, even by using the pressing section that presses the medium from the main roller side, it is possible to realize the adjustment section by simplifying the structure, thereby it is possible to suppress the generation of wrinkles in the medium.

A medium transport device according to a sixth aspect of the disclosure is an aspect according to the first aspect, the adjustment section is a suction section that is disposed at a position downstream of the sub-roller in the transport direction and sucks the medium from a sub-roller side, and the suction section that is disposed at a position overlapping the plurality of sub-rollers in the longitudinal direction and sucks the medium in the first path.

According to this aspect, the suction section that is disposed at a position downstream of the sub-roller in the transport direction and sucks the medium from the sub-roller side. Further, the suction section that is disposed at a position overlapping with the plurality of sub-rollers in the longitudinal direction, and sucks the medium in the first path. With this configuration, even by using the suction section that performs suction from the sub-roller side instead of the pressing section, it is possible to realize the adjustment section by simplifying the structure, thereby it is possible to suppress the generation of wrinkles in the medium.

A medium transport device according to a seventh aspect of the disclosure is an aspect according to the first aspect, includes a feeding section that is disposed at a position upstream of the pair of transport rollers in the transport direction and that feeds the medium wound in a roll shape, a winding section that is disposed at a position downstream of the pair of transport rollers in the transport direction and that winds up the medium being transported; and a processing section that is disposed at a position between the feeding section and the winding section and that performs processing on the medium to be transported, wherein the adjustment section is disposed at a position between the feeding section and the processing section.

According to this aspect, the adjustment section that is disposed at a position between the feeding section and the processing section in the transport direction. With this configuration, it is possible to execute processing by the processing section on the medium in a state in which the generation of wrinkles is suppressed by the adjustment section, and it is possible to improve processing quality.

A medium transport device according to an eighth aspect of the disclosure is an aspect according to the third aspect, includes a support section that is disposed in a region facing the pressing section and that is indirectly contactable with the pressing section with the medium interposed therebetween and a guide section that is disposed at a position downstream of the pressing section in the transport direction and guides the medium to be transported, in an intersecting direction that intersects the transport direction and the longitudinal direction, a pressing position where the pressing section presses the medium with respect to the support section is between a first position where the guide section comes into contact with the medium and a second position where the medium is nipped by the main roller and the sub-roller.

Here, “between” in “between a first position where the guide section comes into contact with the medium and a second position at where the medium is nipped by the main roller and the sub-roller” is used in this specification to include a pressing position where the medium is pressed, being positioned on a straight line connecting the first position and the second position, in a case where the first position and the second position are the same position in the intersecting direction.

According to this aspect, the medium transport device includes a support section that is disposed in a region facing the pressing section and indirectly contactable with the pressing section with the medium: interposed therebetween. With this configuration, the portion of the medium positioned in the first path and the portion of the medium positioned in the second path can be positioned at the same position in a state sandwiched from both the front surface and the back surface by the pressing section and the support section, and thus it is possible to effectively suppress the generation of wrinkles.

Further, according to this aspect, in the cross direction, the pressing position where the pressing section presses the medium against the support section is between the first position where the guide section comes into contact with the medium and the second position where the medium is nipped by the main roller and the sub-roller. With this configuration, it is possible to suppress a displacement amount of a portion of the medium which is pressed by the pressing section and is displaced in the pressing direction to be small.

A medium transport device according to a ninth aspect of the disclosure is an aspect according to the fifth aspect, includes a support section that is disposed in a region facing the pressing section and that is indirectly contactable with the pressing section with the medium interposed therebetween and a guide section that is disposed at a position downstream of the pressing section in the transport direction and guides the medium to be transported, in an intersecting direction that intersects the transport direction and the longitudinal direction, a pressing position where the pressing section presses the medium with respect to the support section is on a straight line connecting a first position where the guide section comes into contact with the medium and a vertex position of the main roller, assuming that the intersecting direction is a height direction.

According to this aspect, the medium transport device includes a support section that is disposed in a region facing the pressing section and indirectly contactable with the pressing section with the medium interposed therebetween With this configuration, the portion of the medium positioned in the first path and the portion of the medium positioned in the second path can be positioned at the same position in a state sandwiched from both the front surface and the back surface by the pressing section and the support section, and thus it is possible to effectively suppress the generation of wrinkles.

Further, according to this aspect, a pressing position at where the pressing section presses the medium against the support section is on a straight line connecting a first position where the guide section comes into contact with the medium and a vertex position of the main roller, assuming that the intersecting direction is a height direction. With this configuration, it is possible to suppress a displacement amount of a portion of the medium which is pressed by the pressing section and is displaced in the pressing direction to be small.

A medium transport device according to a tenth aspect of the disclosure is an aspect according to the fourth aspect, includes a support section that is disposed in a region facing the suction section and that supports the medium being transported, a plurality of openings provided at a position facing the second path of the support section, and a guide section that is disposed at a position downstream of the suction section in the transport direction and guides the medium to be transported, the suction section sucks the medium in the second path through the openings and in an intersecting direction that intersects the transport direction and the longitudinal direction, the support position where the support section supports the medium is between a first position where the guide section comes into contact with the medium and a second position where the medium is nipped by the main roller and the sub-roller.

Here, “between” in “between a first position where the guide section comes into contact with the medium and a second position at where the medium is nipped by the main roller and the sub-roller” is used in this specification to include a pressing position where the medium is pressed, being positioned on a straight line connecting the first position and the second position, in a case where the first position and the second position are the same position in the intersecting direction.

According to this aspect, the medium transport device includes a support section that is disposed in a region facing the suction section and supports the medium to be transported. Further, the suction section sucks the medium in the second path through the opening provided in the support section. With this configuration, the portion of the medium positioned in the first path and the portion of the medium positioned in the second path can be positioned at the same position in a state of being sucked by the suction section and sandwiched from both the front surface and the back surface by the support section, and thus it is possible to effectively suppress the generation of wrinkles.

According to this aspect, in the intersecting direction, the support position where the support section supports the medium is between the first position where the guide section comes into contact with the medium and the second position where the medium is nipped by the main roller and the sub-roller. With this configuration, it is possible to suppress a displacement amount of a portion of the medium which is sucked by the suction section and is displaced in the sanction direction to be small.

A medium transport device according to an eleventh aspect of the disclosure is an aspect according to the sixes aspect, includes a support section that is disposed in a region facing the suction section and that supports the medium being transported, a plurality of openings provided at a position facing the first path of the support section, and a guide section that is disposed at a position downstream of the suction section in the transport direction and guides the medium to be transported, the suction section sucks the medium in the first path through the openings and in an intersecting direction that intersects the transport direction and the longitudinal direction, the support position where the support section supports the medium is on a straight line connecting a first position where the guide section comes into contact with the medium and a vertex position of the main roller, assuming that the intersecting direction is a height direction.

According to this aspect, the medium transport device includes a support section that is disposed in a region facing the suction section and supports the medium to be transported. Further, the suction section sucks the medium in the first path through the opening provided in the support section. With this configuration, the portion of the medium positioned in the first path and the portion of the medium positioned in the second path can be positioned at the same position in a state of being sucked by the suction section and sandwiched from both the front surface and the back surface by the support section, and thus it is possible to effectively suppress the generation of wrinkles.

In addition, according to the aspect, in the intersecting direction, the support position where the support section supports the medium is on the straight line connecting a first position where the guide section comes into contact with the medium and a vertex position of the main roller, assuming the intersecting direction is a height direction. With this configuration, it is possible to suppress a displacement amount of a portion of the medium which is sucked by the suction section and is displaced in the sanction direction to be small.

A medium transport device according to a twelfth aspect of the disclosure is an aspect according to the third aspect, includes the pressing section is a plurality of driven rollers that are driven to rotate about a second shaft and that are disposed at intervals along the longitudinal direction of the main roller, the adjustment section includes a pair of parallel link mechanisms in which the first arm, the second arm, the third arm, and the fourth arm are connected in a state of forming a parallelogram, and wherein the first arms are fixed to a frame, the first arms and the fourth arms are disposed in parallel, the second arms and the third arms are disposed in parallel, both ends of the first shaft are respectively supported at the connection portion between the second arms and the fourth arms of the pair of parallel link mechanisms, both ends of the second shaft are respectively supported at the connection portion between the third arms and fourth arms of the pair of parallel link mechanisms, the second arm is provided with an elastic member that applies an elastic force in a direction that presses the sub-roller against the main roller.

According to this aspect, the adjustment section includes a pair of parallel link mechanisms in which the first arm, the second arm, the third arm, and the fourth arm are connected in a state of forming a parallelogram. The first arm of the parallel link mechanism is fixed to the frame.

Further, both ends of the first shaft are respectively supported at the connection portion between the second arms and the fourth arms of the pair of parallel link mechanisms, both ends of the second shaft are respectively supported at the connection portion between the third arms and fourth arms of the pair of parallel link mechanisms. Furthermore, the second arm is provided with an elastic member that applies an elastic force in the direction that presses the sub-roller against the main roller. When the thickness of the medium transported by the pair of transport rollers changes to a different one, the sub-roller is displaced by the amount corresponding to change in the thickness of the medium based on the elastic force of the elastic member. The first shaft is also displaced by this displacement. That is, the first shaft supported by the connection portion between the second arm and the fourth arm is displaced. When the first shaft is displaced, the second arm supporting the first shaft pivots around a connection portion with the first arm fixed to the frame as a pivot fulcrum. With this pivoting, the third arm constituting the parallel link mechanism, also pivots around the connection portion with the first arm as a pivot fulcrum, similar to the second arm. When the third arm pivots, the second shaft is also displaced. That is, the second shaft supported by the connection portion between the third arm and the fourth arm is displaced. When the second shaft is displaced, the driven roller supported by the second shaft is also displaced.

According to this aspect, in each of the displacements in the parallel link mechanism, since the fourth arm is maintained in a parallel state with the first arm fixed to the frame, the first shaft and the second shaft are equally displaced with respect to a change in the thickness of the medium. Thus, even if the thickness of the medium is changed, the state in which the driven roller forming the pressing section presses the medium in the second path can be maintained.

A recording device according to a thirteenth aspect of the disclosure, includes a recording section that records on the medium and a medium transport device that transports the medium toward the recording section, and wherein the medium transport device includes a main roller configured to apply a feeding force to the medium in the transport direction, the pair of transport rollers includes a plurality of sub-rollers disposed at intervals along the longitudinal direction of the main roller, and being driven to rotate about a first shaft in a state where the medium is nipped between the sub-rollers and the main roller, and an adjustment section configured to adjust a path difference between a first path and a second path, assuming that the first path is a path of the medium nipped and transported between the main roller and the plurality of sub-rollers and the second path is a path of the medium transported in contact with the main roller but not in contact with the plurality of sub-rollers.

According to this aspect, the recording device can achieve the same effect as in the first aspect.

Hereinafter, embodiments of a medium transport device and a recording device including the medium transport device according to the invention will be described with reference to.

In the following description, three axes orthogonal to each other are referred to as an X-axis, a Y-axis, and a Z-axis, respectively, as shown in each drawing. The direction indicated by the arrows of the three axes (X, Y, and Z) is the +direction of each direction, and the opposite direction is the −direction. The Z-axis direction corresponds to a vertical direction, that is, a direction in which gravity acts, a +Z direction indicates a vertically upward direction, and a −Z direction indicates a vertically downward direction. The X-axis direction and the Y-axis direction correspond to horizontal directions. The +Y direction indicates the front direction of the recording device, and the −Y direction indicates the rear direction of the device. The +X direction indicates a right direction of the device, and a −X direction indicates a left direction of the device.

As shown in, a recording deviceof the present embodiment is a so-called digital textile printing machine in which a mediumto be recorded is a fabric. The mediumis transported along a transport pathin a transport direction F by a medium transport device.

The recording deviceapplies an appropriate tension to the mediumby a transport method called Roll to Reel transport method so that the recording execution region of the recording section, which is part of the processing sectionarranged in the transport path, is lifted up.

After the recording process by the recording section, the mediumis heated and dried by a heating sectiondisposed along the transport path, and is wound up by a winding section.