Medium transport device and recording device

Abstract

The medium transport device includes a main roller configured to apply a feeding force to the medium in the transport direction, a 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 that adjusts a path difference between a first path and a second path when a path of the medium that is nipped and transported between the main roller and the plurality of sub-rollers is defined as the first path, and a path of the medium that is transported in contact with the main roller but not in contact with the plurality of sub-rollers 16 is defined as the second path.

What is claimed is: 
     
         1 . A medium transport device comprising:
 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 that are disposed at intervals along a longitudinal direction of the main roller and that are 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.   
     
     
         2 . The medium transport device according to  claim 1 , wherein
 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.   
     
     
         3 . The medium transport device according to  claim 1 , wherein
 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.   
     
     
         4 . The medium transport device according to  claim 1 , wherein
 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.   
     
     
         5 . The medium transport device according to  claim 1 , wherein
 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.   
     
     
         6 . The medium transport device according to  claim 1 , wherein
 the adjustment section is a suction section that is disposed at a position downstream of the sub-roller in the transport direction and that sucks the medium from a sub-roller side and   the suction section is disposed at a position overlapping the plurality of sub-rollers in the longitudinal direction and sucks the medium in the first path.   
     
     
         7 . The medium transport device according to  claim 1 , further comprising:
 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.   
     
     
         8 . The medium transport device according to  claim 3 , further comprising:
 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 that guides the transported medium, wherein   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.   
     
     
         9 . The medium transport device according to  claim 5 , further comprising:
 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 that guides the transported medium, wherein   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.   
     
     
         10 . The medium transport device according to  claim 4 , further comprising:
 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 that guides the transported medium, wherein   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.   
     
     
         11 . The medium transport device according to  claim 6 , further comprising:
 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 that guides the transported medium, wherein   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.   
     
     
         12 . The medium transport device according to  claim 3 , wherein
 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 each of which a first arm, a second arm, a third arm, and a fourth arm are connected in a state of forming a parallelogram,   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 connection portions 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 connection portions between the third arms and fourth arms of the pair of parallel link mechanisms, and   the second arms are provided with an elastic member that applies an elastic force in the direction that presses the sub-rollers against the main roller.   
     
     
         13 . A recording device comprising:
 a recording section that records on the medium and   a medium transport device that transports the medium toward the recording section, wherein   the medium transport device 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 that are disposed at intervals along the longitudinal direction of the main roller and that are 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.