Transporting device and transporting method

A transporting device sends a sheet with the rotation of a first drive roller with the sheet sandwiched between a first drive roller and a driven roller. The sheet is sent to a direction to which a back surface thereof is pressed against a guide surface, and is transported to a second drive roller in a state of being pressed against the guide surface after the guide surface pushing and bending a transport path toward a front surface side. A lifted amount of the sheet from the guide surface is monitored by a sensor, and the transportation is stopped in a case where the lifted amount is equal to or larger than a predetermined amount.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a transporting device and a transporting method in which a sheet-like transportation target object is transported.

2. Description of the Related Art

The following JP2000-089605A, JP2015-218044A, JP2013-160964A, and JP2012-171695A are known as transporting devices that transport a sheet-like transportation target object. In the transporting devices, a plurality of transporting rollers are provided along a transport path of the transportation target object, and the transportation target object is transported by a transporting roller on a downstream side (downstream side transporting roller) pulling the transportation target object sent by a transporting roller on an upstream side (upstream side transporting roller).

SUMMARY OF THE INVENTION

However, the transporting devices of the related art have a problem that damage occurs to the transportation target object, such as a crease and/or fold, as the upstream side transporting roller continues to send the transportation target object despite the fact that the downstream side transporting roller is in a state of being incapable of transporting (pulling) the transportation target object.

In view of the circumstances, an object of the present invention is to provide a transporting device and a transporting method that can prevent damage to a transportation target object.

According to an aspect of the present invention, there is provided a transporting device comprising a guide member, a sensor, and an abnormality indication detection unit. The transporting device has a pair of upstream side transporting rollers, which is disposed to face a front surface side and a back surface side of a sheet-like transportation target object and in which at least one of the upstream side transporting rollers receives supply of drive power and rotates to send the transportation target object to a downstream side, and a downstream side transporting roller, which is disposed on the downstream side of the upstream side transporting rollers, to thereby transport the transportation target object by means of the upstream side transporting roller and the downstream side transporting roller. The guide member has a guide surface, which supports the transportation target object from the back surface side, and is disposed between the upstream side transporting rollers and the downstream side transporting roller. The sensor measures a distance between the guide surface and the transportation target object. The abnormality indication detection unit detects that there is a transport abnormality indication in a case where the distance measured by the sensor is equal to or larger than a predetermined distance. The upstream side transporting rollers send the transportation target object in a direction to which the transportation target object is pressed against the guide surface, and a transport path of the transportation target object is pushed and bent toward the front surface side of the transportation target object by the guide surface.

It is preferable that the transport path is pushed and bent toward the front surface side of the transportation target object by the downstream side transporting roller.

A transportation stopping unit that stops transportation of the transportation target object in a case where the transport abnormality indication is detected may be provided.

A cleaner that slidingly contacts a front surface of the transportation target object may be disposed at a position facing the downstream side transporting roller with the transportation target object sandwiched therebetween.

The transportation target object may be a flat sheet.

At least one of the upstream side transporting rollers may have a curved part of which an outer circumferential surface is curved as an outer diameter differs according to a position in an axial direction.

According to another aspect of the present invention, there is provided a transporting method that has a sending step, a guiding step, and a pulling step, and transports a sheet-like transportation target object. In the sending step, the transportation target object is sent by a pair of upstream side transporting rollers, which is disposed to face a front surface side and a back surface side of the transportation target object and in which at least one of the upstream side transporting rollers receives supply of drive power and rotates. In the guiding step, the transportation target object is supported from the back surface side by a guide surface of a guide member disposed on a downstream side of the upstream side transporting rollers. In the pulling step, the transportation target object is pulled by a downstream side transporting roller disposed on a downstream side of the guide member. In the sending step, a transport path of the transportation target object is pushed and bent toward the front surface side of the transportation target object by sending the transportation target object in a direction to which the transportation target object is pressed against the guide surface. In the guiding step, a distance between the guide surface and the transportation target object is measured by a sensor, and in a case where the distance measured by the sensor is equal to or larger than a predetermined distance, it is detected that there is a transport abnormality indication.

In the present invention, damage to the transportation target object can be prevented.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

InFIG. 1, a transporting device10according to an embodiment of the present invention transports a sheet14(transportation target object) brought in from a pre-process12to a post-process16and cleans a front surface of the sheet14during the transportation. In the embodiment, the sheet14is a flat sheet (independent one sheet) such as a photo, and is transported in a state where the front surface faces upward and a back surface faces downward.

The transporting device10comprises a first drive roller20(upstream side transporting roller), a second drive roller22(downstream side transporting roller), a driven roller24(upstream side transporting roller), and a cleaning roller26, in addition to a controller18(an abnormality indication detection unit and a transportation stopping unit) that controls driving of each unit.

The first drive roller20and the second drive roller22are rollers that rotate by receiving the supply of drive power from a drive power supplying unit (not illustrated) such as a motor, and rotates as driving thereof is controlled by the controller18. On the other hand, the driven roller24is a roller that rotates by following the rotation of the first drive roller20. The driven roller24is disposed so as to face the first drive roller20with a transport path30of the sheet14sandwiched therebetween. The sheet14is sandwiched between the first drive roller20and the driven roller24, and is sent to a downstream side with the rotation of the first drive roller20(refer toFIG. 2).

The second drive roller22and the cleaning roller26are disposed on the downstream side of the first drive roller20and the driven roller24. In addition, the second drive roller22and the cleaning roller26are disposed so as to face each other with the transport path30sandwiched therebetween. A cleaning sheet32(cleaner) is wound around an outer circumference of the cleaning roller26. The front surface of the sheet14sent from the first drive roller20and the driven roller24is caused to slidingly contact the cleaning sheet32with the rotation of the second drive roller22, and the sheet passes below the cleaning roller26(between the cleaning roller26and the second drive roller22) (refer toFIG. 4). Accordingly, the front surface of the sheet14is cleaned.

Although the sheet14is transported and cleaned in the transporting device10as described above, the sheet14becomes damaged in a case where the sheet14cannot smoothly pass between the cleaning roller26and the second drive roller22. Such a phenomenon, that is, so-called jamming occurs as the sheet14is continued to be sent from the first drive roller20and the driven roller24despite the fact that the second drive roller22does not normally transport the sheet14, such as a leading end (downstream end part) of the sheet14is not guided between the cleaning roller26and the second drive roller22. In a case where jamming occurs, damage including a crease and/or fold occurs to the sheet14when passing the front (upstream side) of the cleaning roller26and the second drive roller22and/or between the cleaning roller26and the second drive roller22.

In order for the transporting device10to prevent jamming described above, a guide member34is provided between the upstream side transporting rollers (the first drive roller20and the driven roller24) and the downstream side transporting roller (the second drive roller22), and the sheet is transported while the back surface of the sheet14is pressed against the guide member34.

As illustrated inFIG. 2, the guide member34has an upper surface that is a guide surface36, and is disposed below the transport path30. In addition, the guide member34and the upstream side transporting rollers (the first drive roller20and the driven roller24) are configured in a state where the transport path30of the sheet14sent by the upstream side transporting rollers is pushed and bent toward a front surface side by the guide surface36. Specifically, in the embodiment, the guide surface36is levelled, and a disposition position of the driven roller24is a position offset to the downstream side with respect to a vertical direction of the first drive roller20.

By doing so, after being sent obliquely downward from the upstream side transporting rollers to the guide surface36, the sheet14is pushed and bent toward the front surface side (horizontal direction) by abutting against the guide surface36(the transport path30is pushed and bent) and is transported to the downstream side transporting roller (the second drive roller22) along the guide surface36in a state where the back surface is pressed against the guide surface36. The up-and-down movement of the sheet14(in particular, a leading end part of the sheet14) is suppressed by transporting (sending) the sheet14while pressing against the guide surface36as described above. Consequently, stable transportation is possible, thereby contributing to the prevention of jamming.

In addition, a sensor38is provided in the transporting device10, and detects a lifted amount of the sheet14from the guide surface36(a distance between the guide surface36and the back surface of the sheet14). The sensor38is formed by, for example, a known distance-measuring sensor that measures a distance using laser light, and is disposed below the guide member34. The guide member34is provided with a through-hole40that exposes the back surface of the sheet14, and a distance to the back surface of the sheet14is measured via the through-hole40.

The controller18controls the driving of the sensor38, and information obtained from the sensor38, that is, information related to a distance from the sensor38to the back surface of the sheet14is input to the controller18. As shown inFIG. 3, in a case where a lifted amount of the sheet14(a distance from the sensor38to the sheet14) is equal to or larger than a predetermined amount (a predetermined distance), the controller18determines that there is a jamming indication (transport abnormality indication) based on the information input from the sensor38, and stops the transportation of the sheet14(the rotation of the first drive roller20and the second drive roller22). In the embodiment, the predetermined distance is a distance longer than a distance from the sensor38to the guide surface36by 2 mm. That is, in the embodiment, in a case where the lifted amount of the sheet14(a distance from the guide surface36) is 2 mm or larger, the transportation of the sheet14is stopped under an assumption that there is a jamming indication.

By stopping the transportation as described above immediately before a timing of moment when the distance from the sensor38to the sheet14is equal to or larger than the predetermined distance, that is, immediately before a timing of moment when the sheet14is lifted from the guide surface36by the predetermined amount (predetermined distance) or more, jamming can be more reliably prevented. That is, since jamming occurs in a case where the upstream side transporting rollers continue to send the sheet14despite the fact that the downstream side transporting roller does not transport (pull) the sheet, a state where the sheet14is simply lifted from the guide surface36(immediately before a timing of moment of being lifted) is not enough to be called jamming. However, in a case where the sheet14is lifted from the guide surface36despite the fact that the sheet is transported while being pressed to the guide surface36, there is a possibility of developing into jamming as the transportation continues. Since the transporting device10stops the transportation at a stage of such an indication (a stage before jamming occurs), jamming can be more reliably prevented.

As illustrated inFIG. 4, the transporting device10is configured such that the transport path30of the sheet14from the guide surface36to the cleaning roller26(the cleaning sheet32) is pushed and bent toward the front surface side by the second drive roller22. Specifically, in the embodiment, the second drive roller22and the cleaning roller26are disposed in a state where a position of bonding between the second drive roller22and the cleaning roller26(the cleaning sheet32) (a position where the sheet14passes while slidingly contacting the cleaning sheet32) is a position higher than the guide surface36.

By doing so, after being horizontally sent from the guide surface36, the sheet14is pushed and bent toward the front surface side (the transport path30is pushed and bent) by abutting against a circumferential surface of the second drive roller22before slidingly contacting the cleaning roller26(the cleaning sheet32), and is guided (transported) to the cleaning roller26(the cleaning sheet32) along the rotation of the second drive roller22in a state where the back surface is pressed against the second drive roller22. Since the sheet14is guided (transported) to the position of bonding between the second drive roller22and the cleaning roller26(the cleaning sheet32) in a state of being pressed against the second drive roller22as described above, more reliable guiding (transportation) is possible, contributing to the prevention of jamming.

Hereinafter, procedures of cleaning the sheet14while transporting the sheet by the transporting device10described above will be described. The sheet14is brought into the transporting device10from the pre-process12. The sheet14brought in from the pre-process12is sent to the downstream side by the upstream side transporting rollers (the first drive roller20and the driven roller24) (sending step).

In the sending step, the sheet14is sent to a direction to which the back surface is pressed against the guide surface36. Accordingly, in a state where the transport path30is pushed and bent toward the front surface side of the sheet14and the sheet14is pressed against the guide surface36(a state of being supported from a back surface side), the sheet is sent (transported) to the downstream side transporting roller (the second drive roller22) (guiding step). By doing so, jamming (transport abnormality) can be prevented (refer toFIG. 2).

In addition, in the guiding step, the sensor38measures the lifted amount of the sheet14from the guide surface36. In a case where the lifted amount is equal to or larger than the predetermined amount, it is determined that there is a jamming indication, and the transportation (the driving of the first drive roller20and the second drive roller22) is stopped. Accordingly, jamming is prevented (refer toFIGS. 2 and 3).

The sheet14sent from the guide member34(the guide surface36) to the downstream side is pulled by the second drive roller22and is further transported to the downstream side (pulling step), and the front surface of the sheet is cleaned by the cleaning roller26(the cleaning sheet32) slidingly contacting the front surface during the transportation (refer toFIG. 4).

In addition, in the pulling step, the sheet14is sent to a direction to which the back surface is pressed against the second drive roller22. Accordingly, the sheet14abuts against the circumferential surface of the second drive roller22before slidingly contacting the cleaning roller26(the cleaning sheet32), and the transport path30is pushed and bent toward the front surface side of the sheet14. In a state of being pressed against the second drive roller22, the sheet14is guided (transported) to the cleaning roller26(the cleaning sheet32) along with the rotation of the second drive roller22. Accordingly, jamming is prevented (refer toFIG. 4).

As described above, jamming can be prevented in the transporting device10by a configuration where the sheet14is pressed against the guide surface36and the transport path30is pushed and bent toward the front surface side of the sheet14(hereinafter, a configuration1), a configuration where transportation stops in a case where the lifted amount of the sheet14from the guide surface36is equal to or larger than the predetermined amount (hereinafter, a configuration2), and a configuration where the sheet14is pressed against the downstream side transporting roller (the second drive roller22) and the transport path30is pushed and bent toward the front surface side of the sheet14(hereinafter, a configuration3).

The present invention is not limited to the embodiment, and detailed configurations can be changed as appropriate. For example, although an example comprising all of the configurations1to3is described in the embodiment, jamming may be prevented by only one configuration or a combination of two configurations out of the configurations1to3.

In addition, as illustrated inFIG. 5, a roller having a curved part may be used as the upstream side transporting roller. The same members as the embodiment described above will be assigned with the same reference signs and description thereof will be omitted inFIG. 5.

InFIG. 5, upstream side transporting rollers50and52, between which the sheet14is sandwiched, send the sheet14to the downstream side by at least one of the upstream side transporting rollers receiving the supply of drive power and rotating. A diameter of a center part of the upstream side transporting roller50in an axial direction that is parallel to the front surface and back surface of the sheet14and is orthogonal to a transporting direction (transport path) of the sheet14is formed to be larger than diameters of both side parts in the axial direction. Accordingly, a curved outer circumferential surface becomes a curved part54. In contrast to the upstream side transporting roller50, by forming a diameter of a center part of the upstream side transporting roller52in the axial direction smaller than diameters of both side parts in the axial direction, a curved outer circumferential surface becomes a curved part56.

Thus, since the sheet14sent from the upstream side transporting rollers50and52is curved in the axial direction and thereby stiffness with respect to pushing and bending of the front surface side and the back surface side is high, the sheet can be more firmly pressed against the guide surface36(refer toFIG. 2) and/or the second drive roller22(refer toFIG. 4). Accordingly, jamming can be prevented more reliably.

Although the roller (roller of which the entire outer circumferential surface is the curved part) of which the entire outer circumference (the whole in the axial direction) is curved is described as an example inFIG. 5, the same effects can be achieved even in a case where a roller of which a part of an outer circumference (a part in the axial direction) is curved is used as the upstream side transporting roller. In addition, although an example in which a curved part is provided also in one upstream side transporting roller so as to correspond to the other upstream side transporting roller is described inFIG. 5, a configuration where a curved part is provided in only one upstream side transporting roller and an outer circumferential part of the other upstream side transporting roller is formed by an elastic body, for example, rubber, so as to be modified to correspond to one upstream side transporting roller instead of providing a curved part in the other upstream side transporting roller may be adopted.

In addition, although an example in which the sheet is cleaned by the cleaning sheet wound around the cleaning roller is described in the embodiment, the sheet may be directly cleaned by a cleaning roller which is assigned to the outer circumferential surface and has the same function as the cleaning sheet, instead of providing the cleaning sheet.

In addition, although an example in which the present invention is applied to the transporting device that performs transportation and cleaning is described in the embodiment, the present invention may be applied to a transporting device that performs only transportation or processing other than transportation and cleaning (for example, stretching with respect to a width direction and/or a transporting direction and/or application of a material for adding a function with respect to a base sheet).

In addition, although an example in which the present invention is applied to the transporting device that transports the flat sheet is described in the embodiment, the present invention may be applied to a transporting device that transports a series of strip-like sheets. However, the present invention prevents malfunction (jamming) that occurs due to the continuation of sending by the upstream side transporting roller despite the fact that the downstream side transporting roller is in a transportation incapable state, such malfunction is likely to occur in a case where the leading end part of the sheet reaches the downstream side transporting roller or passes the downstream side transporting roller. That is, the malfunction described above is unlikely to occur in the first place in the transporting device that transports the strip-like sheet. Accordingly, the present invention can obtain a remarkable effect in a case of being applied to the transporting device that transports the flat sheet.

In addition, although an example in which transportation stops in a case where the lifted amount of the sheet14(the distance from the guide surface36) is 2 mm or more is described in the embodiment, the lifted amount of the sheet14at which the transportation is stopped can be freely set.

Herein, it is preferable for the lifted amount of the sheet14at which the transportation is stopped to be smaller from the perspective of more reliable prevention of jamming. For this reason, it is more preferable to stop the transportation in a case where the lifted amount is 1 mm, and it is even more preferable to stop the transportation in a case where the lifted amount is 0.5 mm.

As the lifted amount of the sheet14at which the transportation is stopped is set to be smaller, transportation is more likely to be stopped despite the fact that a lifted degree is not enough to develop into jamming. Thus, there is a high possibility that smooth transportation is obstructed. For this reason, it is preferable that the lifted amount of the sheet14at which transportation is stopped is approximately 2 mm, more specifically, in a range of 1.5 mm or more to 2.5 mm or less in consideration of a perspective of both of prevention of jamming and smooth transportation.

In addition, since it is sufficient that the guide member34is a member that is disposed between the upstream side transporting rollers and the downstream side transporting roller and guides the sheet14from the back surface side, specific configurations, such as a shape and a material, and a disposition position are not limited to the embodiment.

However, in order to more reliably prevent abnormal transportation by the sheet14being wrapped below the guide member34due to a gap between the upstream side transporting rollers and the guide member34, it is preferable that the gap between the upstream side transporting rollers and the guide member34is as small as possible.

In addition, even when the sheet14is guided above the guide member34(the guide surface36), the sheet14is obstructed in a case where an approach angle of the sheet14to the guide surface36is excessively steep (a case of being close to vertical), and there is a possibility that the sheet14does not pass above the guide surface36without being pressed against the guide surface36in a case where the approach angle is slight (a case of being close to 0°). For this reason, it is preferable that the approach angle of the sheet14to the guide surface36is 10° or more and 30° or less, and it is more preferable that the approach angle is 15° or more and 25° or less.

EXPLANATION OF REFERENCES