Recording device

Abstract

To correct oblique conveyance of a medium without reducing force for conveying a medium.SOLUTION: A recording device 1 comprises: a conveying roller pair 30 that conveys a medium P; a rotating body 31, provided closer to a downstream on a conveying passage for the medium P than the conveying roller pair 30, which can switch between a first state where a tip of the medium P being nipped by the conveying roller pair 30 is allowed to pass and a second state where the tip of the medium P being nipped by the conveying roller pair 30 is not allowed to pass; and a recording part 12, provided closer to the downstream on the conveying passage than the rotating body 31, which performs recording on the medium P by discharging liquid. The conveying roller pair 30 includes first rollers 61 with teeth that have a plurality of convex parts 67 that can point-contact the medium P at an outer periphery part 66 and make the plurality of convex parts 67 nip the medium P, which is arranged only in a center region S1 of regions equally divided into three in a width direction corresponding to a direction of rotary shafts of the first rollers 61 with teeth on the conveying passage.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a recording apparatus.

Background Art

[0002] Conventionally, recording apparatuses with various configurations have been used. Among these, there is a recording apparatus that can correct the skew conveyance of a medium when the medium conveyed along a conveyance path is skew-conveyed. For example, Patent Document 1 discloses a recording apparatus including a pair of correction rollers, which can correct the skew conveyance of a medium by abutting the medium conveyed along a supply path against the pair of correction rollers.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in conventional recording apparatuses capable of correcting skew conveyance of a medium, depending on the type of medium used and the configuration of the conveyance unit that conveys the medium, even if a mechanism for correcting skew conveyance of the medium is provided, there are cases where skew conveyance of the medium cannot be sufficiently corrected. For example, when correcting skew conveyance in a recording apparatus including a pair of correction rollers and a conveyance unit capable of abutting the medium against the pair of correction rollers, skew conveyance is corrected by deflecting and conveying the medium by the conveyance unit with the leading end of the medium abutted against the pair of correction rollers. In such a recording apparatus, for example, when conveying cardboard, it becomes difficult to deflect the medium, and it becomes difficult to correct skew conveyance. Further, for example, when using a pair of conveyance rollers with a long nip width as the conveyance unit, since the medium is nipped long in the width direction, it is difficult for the medium to shift in the width direction, and it becomes difficult to correct skew conveyance. On the other hand, if the nip width of the pair of conveyance rollers is simply shortened, the force for conveying the medium decreases.

Means for Solving the Problems

[0005] In order to solve the above problems, a recording apparatus of the present invention includes a pair of conveyance rollers that convey a medium, and is provided on the downstream side in the conveyance path of the medium from the pair of conveyance rollers, and passes the leading end of the medium being nipped by the pair of conveyance rollers. A rotating body capable of switching between a first state and a second state in which the leading end of the medium being nipped by the pair of conveyance rollers is not passed through, and a recording unit provided on the downstream side of the conveyance path from the rotating body, and performing recording on the medium by discharging a liquid. The pair of conveyance rollers includes a first toothed roller having a plurality of convex portions on the outer peripheral portion capable of point contact with the medium, and nipping the medium by the plurality of convex portions, and is arranged only in a central region when the conveyance path is divided into three in the width direction corresponding to the rotation axis direction of the first toothed roller.

Brief Description of the Drawings

[0006]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Mode for Carrying Out the Invention

[0007] Hereinafter, the present invention will be schematically described. The recording apparatus according to the first aspect includes a pair of conveying rollers that convey a medium, and a rotating body provided downstream of the pair of conveying rollers in the conveying path of the medium. The rotating body can be switched between a first state in which the leading end of the medium in the nip of the pair of conveying rollers passes through and a second state in which the leading end of the medium in the nip of the pair of conveying rollers does not pass through. The recording apparatus also includes a recording unit provided downstream of the rotating body in the conveying path and performing recording on the medium by discharging liquid. The pair of conveying rollers includes a first toothed roller having a plurality of convex portions on its outer peripheral portion that can be in point contact with the medium, and nipping the medium by the plurality of convex portions. The pair of conveying rollers is characterized in that it is arranged only in the central region when the conveying path is divided into three in the width direction corresponding to the rotation axis direction of the first toothed roller.

[0008] According to this aspect, the pair of conveying rollers is arranged only in the central region when the conveying path is divided into three in the width direction. Therefore, the medium can be rotated with the center of the nip position narrow in the width direction in the central region as the center of the rotation axis, and the skew conveyance of the medium can be effectively corrected. In addition, since the pair of conveying rollers includes a first toothed roller that nips the medium by a plurality of convex portions, the medium can be nipped by the plurality of convex portions of the first toothed roller and conveyed, and a decrease in the force for conveying the medium can be suppressed. That is, according to this aspect, the skew conveyance of the medium can be corrected without reducing the force for conveying the medium.

[0009] The second aspect is characterized in that, in the first aspect, the first toothed roller includes a plurality of tooth members having a plurality of convex portions along the outer peripheral portion in the width direction.

[0010] According to this aspect, the first toothed roller includes a plurality of toothed members in the width direction, each having a plurality of convex portions along the outer peripheral portion. Therefore, even if the number of convex portions of each toothed member is reduced, the total number of convex portions of the first toothed roller can be increased. By reducing the number of convex portions of each toothed member, it becomes possible to facilitate the manufacture of the toothed member and reduce the cost. In addition, by providing a plurality of toothed members, the total number of convex portions of the first toothed roller can be increased, so that a decrease in the force for conveying the medium can be effectively suppressed.

[0011] A third aspect is that, in the first or second aspect, the rotating body includes a second toothed roller having a plurality of convex portions on the outer peripheral portion that can be in point contact with the medium, and an outer diameter of the first toothed roller is equal to or larger than an outer diameter of the second toothed roller.

[0012] According to this aspect, the outer diameter of the first toothed roller can be increased. By increasing the outer diameter of the first toothed roller, the time from when one convex portion bites the medium until the next convex portion bites the medium can be lengthened. For example, in the case of performing recording on both sides of the medium, when the first toothed roller contacts the medium with liquid attached thereto, the time from when one convex portion contacts the medium until the next contact with the medium can be lengthened. By lengthening this time, this time can be made a sufficient drying time for the liquid, and reattachment of the liquid attached to the convex portion to the medium can be suppressed.

[0013] A fourth aspect is that, in any one of the first to third aspects, the conveyance path includes a supply path for supplying the medium placed on the placement portion to the recording portion, and a reversal path for reversing the front and back of the medium recorded by the recording portion and supplying the medium with the front and back reversed to the supply path, the pair of conveyance rollers and the rotating body are arranged in the supply path, and the supply path includes a vertically upward path for conveying the medium vertically upward between the pair of conveyance rollers and the rotating body.

[0014] According to this aspect, the supply path includes a vertically upward path. Therefore, it is possible to reduce the supply path in the horizontal direction, and the installation area of the recording device can be reduced.

[0015] A fifth aspect is that, in the fourth aspect, the supply path includes a curved path between the pair of conveying rollers and the rotating body, and the curved path is provided with a deflection space that expands outward to allow deflection of the medium being conveyed along the curved path.

[0016] According to this aspect, the curved path is provided with a deflection space that expands outward to allow deflection of the medium being conveyed along the curved path. Therefore, the deflection space can be utilized during skew correction, and the skew conveyance of the medium can be effectively corrected by utilizing the restoring force associated with the deflection of the medium.

[0017] A sixth aspect is that, in the fifth aspect, the supply path is provided with a fixed end upstream of the deflection space and a free end downstream of the fixed end, and includes a swing member that can swing with the fixed end as a swing axis, and the deflection space extends wider than the swing member to the outside.

[0018] When the medium is being conveyed, if the medium deflects too much outward, there is a risk of conveyance failure. However, according to this aspect, by swinging the swing member, it is possible to suppress the medium from deflecting too much outward during conveyance of the medium. Also, by swinging the swing member, during skew correction, the medium can be sufficiently deflected. Further, by providing the swing member, even if a large deflection space is taken, the risk of conveyance failure can be reduced, so that even when using a medium such as thick paper for which skew correction is generally difficult, the skew conveyance of the medium can be effectively corrected.

[0019] A seventh aspect is that, in the fifth or sixth aspect, the recording unit is located on the same side as the outside with respect to the conveyance path, and the first toothed roller is located on the same side as the inside of the curved path with respect to the conveyance path.

[0020] According to this aspect, the recording unit is located on the same side as the outer side of the curved path with respect to the conveyance path. Since there is no need to provide the recording unit in the area surrounded by the supply path and the inversion path, it is not necessary to make the area surrounded by the supply path and the inversion path wide, and the recording apparatus can be miniaturized.

[0021] The eighth aspect is any one of the first to seventh aspects, wherein the rotating body is composed of a pair of rollers having a rotation axis in the width direction, and the nip width in the width direction of the conveyance roller pair is 0.25 times or less the nip width in the width direction of the rotating body.

[0022] According to this aspect, the nip width in the width direction of the conveyance roller pair is 0.25 times or less the nip width in the width direction of the rotating body. By adopting such a configuration, the effect of skew correction can be particularly improved.

[0023] The ninth aspect is any one of the first to eighth aspects, wherein the nip force of the first toothed roller on the medium is 3.0 N or more and 6.0 N or less.

[0024] According to this aspect, the nip force of the first toothed roller on the medium is 3.0 N or more and 6.0 N or less. By adopting such a configuration, while suppressing a decrease in the conveyance property of the medium, for example, adhesion of liquid to the first toothed roller when recording on both sides of the medium can be suppressed.

[0025] The tenth aspect is any one of the first to ninth aspects, wherein the angle formed by the tip of the convex portion when the first toothed roller is viewed along the width direction is 60° or more and 70° or less.

[0026] When the number of convex portions increases, foreign substances such as liquid are likely to adhere to the tooth member. However, according to this aspect, since the angle formed by the tip portions of the convex portions is 60° or more, it is possible to suppress an excessive increase in the number of convex portions, and it is possible to suppress the adhesion of foreign substances such as liquid to the tooth member. Further, when the number of convex portions per first toothed roller becomes too small, the conveying force of the medium tends to decrease. However, according to this aspect, since the angle formed by the tip portions of the convex portions is 70° or less, the interval between adjacent convex portions in the circumferential direction can be shortened in each tooth member, and it is possible to suppress an excessive decrease in the number of convex portions per tooth member, and it is possible to suppress a decrease in the conveying force of the medium.

[0027] A tenth aspect is characterized in that, in any one of the first to ninth aspects, the thickness of the convex portion in the width direction is 0.05 mm or more and 0.10 mm or less.

[0028] It is difficult to simply make the thickness of the convex portion in the width direction thin, which causes a cost increase. However, according to this aspect, since the thickness of the convex portion in the width direction is 0.05 mm or more, the convex portion can be easily formed by press working or the like, and the tooth member can be easily formed at low cost. Further, if the thickness of the convex portion in the width direction is made too thick, foreign substances such as liquid are likely to adhere to the convex portion, and there is a risk that the foreign substances adhering to the convex portion are transferred to the medium. However, according to this aspect, since the thickness of the convex portion in the width direction is 0.10 mm or less, it is possible to suppress making the thickness of the convex portion in the width direction too thick, and it is possible to reduce the risk of foreign substances adhering to the convex portion being transferred to the medium.

[0029] Hereinafter, the present invention will be specifically described. Hereinafter, an inkjet printer 1 that performs recording by ejecting ink, which is an example of a liquid, onto a medium P typified by recording paper will be described as an example of a recording apparatus. Hereinafter, the inkjet printer 1 will be abbreviated as the printer 1. In each figure, the X-Y-Z coordinate system shown is a rectangular coordinate system, the Y-axis direction is the width direction intersecting the conveyance direction of the medium P, corresponding to the depth direction of the apparatus and corresponding to the rotation axis direction of each of the following conveyance roller pairs. The X-axis direction is the apparatus width direction, with the +X direction being the left side and the -X direction being the right side as viewed from the operator of the printer 1. The Z-axis direction is the vertical direction, i.e., the apparatus height direction, with the +Z direction being the upward direction and the -Z direction being the downward direction. Hereinafter, the direction in which the medium P is being sent will be referred to as "downstream", and the opposite direction may be referred to as "upstream". Also, in FIG. 1, the conveyance path of the medium P is shown by a broken line. In the printer 1, the medium P is conveyed through the conveyance path shown by the broken line.

[0030] First, referring to FIG. 1, an overall overview of the printer 1 will be described. As shown in FIG. 1, the printer 1 includes a plurality of medium cassettes along the vertical direction at the lower part of the apparatus main body 2. In the present embodiment, these medium cassettes of the second medium cassette 4, the third medium cassette 5, and the fourth medium cassette 6 are provided in order from the uppermost first medium cassette 3 downward. Each medium cassette is an example of a placement part capable of placing and accommodating the medium P.

[0031] For each medium cassette, a pick-up roller for sending out the accommodated medium P in the -X direction is provided. A pick-up roller 21 is provided for the first medium cassette 3, a pick-up roller 22 is provided for the second medium cassette 4, a pick-up roller 23 is provided for the third medium cassette 5, and a pick-up roller 24 is provided for the fourth medium cassette 6.

[0032] Also, for each media cassette, a pair of feed rollers is provided to feed the media P fed out in the -X direction in an obliquely upward direction including an -X direction component and a +Z direction component. A pair of feed rollers 25 is provided for the first media cassette 3, a pair of feed rollers 26 is provided for the second media cassette 4, a pair of feed rollers 27 is provided for the third media cassette 5, and a pair of feed rollers 28 is provided for the fourth media cassette 6. Hereinafter, the "roller pair" shall be composed of a driving roller driven by a motor (not shown) unless otherwise specified and a driven roller that rotates in a driven manner in contact with the driving roller.

[0033] The media P sent out from the first media cassette 3 and sent in an obliquely upward direction by the pair of feed rollers 25 receives a feeding force from the pair of conveying rollers 29 and is sent in an obliquely upward direction including a +X direction component and a +Z direction component. The media P sent out from the second media cassette 4 and sent in an obliquely upward direction by the pair of feed rollers 26 receives a feeding force from the pair of conveying rollers 130 and is sent upward and reaches the pair of conveying rollers 29. The media P sent out from the third media cassette 5 and sent in an obliquely upward direction by the pair of feed rollers 27 is sent upward by the pair of conveying rollers 131 and the pair of conveying rollers 130 and reaches the pair of conveying rollers 29. The media P sent out from the fourth media cassette 6 and sent in an obliquely upward direction by the pair of feed rollers 28 is sent upward by the pair of conveying rollers 132, the pair of conveying rollers 131, and the pair of conveying rollers 130 and reaches the pair of conveying rollers 29. The pair of conveying rollers 29 sends the media P in an obliquely upward direction including a +X direction component and a +Z direction component as described above.

[0034] The conveyance path downstream from the pair of conveyance rollers 29 is curved so as to be convex upward, and the medium P reaches the pair of conveyance rollers 30 through this curved path portion. Further, a pair of conveyance rollers 31 is provided on the downstream side of the pair of conveyance rollers 30. Hereinafter, the conveyance path until the medium P sent out from each medium cassette reaches the pair of conveyance rollers 31 is referred to as "supply path T1". Also, among the supply path T1, the path portion that is curved so as to be convex upward between the pair of conveyance rollers 29 and the pair of conveyance rollers 30 is referred to as "first curved path R1". The supply path T1 is a path that reverses the medium P sent out from each medium cassette in the conveyance direction including a component in the +X direction, which is the direction opposite to the medium sending direction from each medium cassette, i.e., the -X direction. And this supply path T1 merges with the inversion path T4, which will be described later, at a position upstream of the pair of conveyance rollers 30.

[0035] Note that the external pair of conveyance rollers 18 shown outside the apparatus main body 2 in the vicinity of the pair of conveyance rollers 29 is a pair of rollers provided in an additional unit (not shown). This additional unit is configured to be able to accommodate the medium P, and the medium P sent out from a feeding roller (not shown) can be supplied into the printer 1 by the external pair of conveyance rollers 18.

[0036] Also, a supply tray 7 that protrudes from the side surface of the apparatus main body 2 to the outside of the apparatus is provided in the vicinity of the first curved path R1. The supply tray 7 is a tray for manually feeding the medium P, and the medium P is supplied into the printer 1 from the supply tray 7 by the supply roller 19 and the separation roller 20. Note that the medium P fed into the apparatus through the supply tray 7 will enter the supply path T1.

[0037] The medium P that receives the feeding force from the pair of conveyance rollers 29 reaches the pair of conveyance rollers 31 through a curved path that is curved so as to be convex downward. Hereinafter, the region from the pair of conveyance rollers 30 to the pair of conveyance rollers 31 in the curved path that is curved so as to be convex downward between the pair of conveyance rollers 34 and the pair of conveyance rollers 31, which will be described later, is referred to as "second curved path R2".

[0038] The medium P that receives the feeding force from the pair of conveying rollers 31 is sent between the line head 12, which is an example of a recording unit, and the conveying belt 13, that is, to the recording position facing the line head 12. Hereinafter, the conveying path from the pair of conveying rollers 31 to the pair of conveying rollers 32 is referred to as the "recording-time conveying path T2". The line head 12 executes recording by discharging ink, which is an example of a liquid, onto the surface of the medium P. The line head 12 is an ink discharge head configured such that nozzles for discharging ink cover the entire width of the medium in the medium width direction, and is configured as an ink discharge head capable of performing recording over the entire width of the medium without moving in the medium width direction. However, the ink discharge head is not limited to this, and may be of a type mounted on a carriage and discharging ink while moving in the medium width direction.

[0039] The ink discharged from the line head 12 is supplied from the ink storage unit 10 to the line head 12 via a tube (not shown). The ink storage unit 10 is composed of a plurality of ink tanks arranged along the X-axis direction. The ink as waste liquid discharged for maintenance from the line head 12 toward a flushing cap (not shown) is stored in the waste liquid storage unit 11.

[0040] The conveying belt 13 is an endless belt wound around the pulley 14 and the pulley 15, and at least one of the pulley 14 and the pulley 15 rotates by being driven by a motor (not shown). The medium P is conveyed to a position facing the line head 12 while being adsorbed to the belt surface of the conveying belt 13. As the adsorption of the medium P to the conveying belt 13, a known adsorption method such as an air suction method or an electrostatic adsorption method can be adopted.

[0041] Here, the recording conveyance path T2 passing through the position facing the line head 12 is configured to convey the medium P obliquely upward at an angle with respect to the horizontal direction and the vertical direction. This obliquely upward conveyance direction is a direction including an -X direction component and a +Z direction component in FIG. 1. With such a configuration, the horizontal dimension of the printer 1 can be suppressed. In this embodiment, the recording conveyance path T2 is set to an inclination angle in the range of 50° to 70° with respect to the horizontal direction, and more specifically, is set to an inclination angle of approximately 60°.

[0042] The medium P on which recording has been performed on the first surface by the line head 12 is sent in an obliquely upward direction including an -X direction component and a +Z direction component by a pair of conveyance rollers 32 located downstream of the conveyance belt 13. A flap 41 is provided downstream of the pair of conveyance rollers 32, and the conveyance direction of the medium P is switched by the flap 41. When discharging the medium P as it is, the conveyance path of the medium P is switched by the flap 41 to face the upper pair of conveyance rollers 37. A flap 42 is further provided downstream of the pair of conveyance rollers 37, and the conveyance path is switched by the flap 42 either to discharge from the discharge position A1 or to convey to the pair of conveyance rollers 38 located vertically above. When the medium P is sent toward the pair of conveyance rollers 38, it is discharged from the discharge position A2. The medium P discharged from the discharge position A1 is received by a discharge tray 8 inclined in an obliquely upward direction including a +X direction component and a +Z direction component. The medium P discharged from the discharge position A2 is received by an optional tray (not shown).

[0043] When recording is performed not only on the first side but also on the second side of the medium P, the medium P is sent in an obliquely upward direction including an -X direction component and a +Z direction component by the flap 41, passes through the branch position K1, and enters the switchback path T3. In the present embodiment, the switchback path T3 is the upper conveyance path from the branch position K1. A pair of conveyance rollers 39 is provided on the switchback path T3. The medium P that has entered the switchback path T3 is conveyed upward by the pair of conveyance rollers 39. When the rear end of the medium P has passed through the branch position K1, the rotation direction of the pair of conveyance rollers 39 is switched, and thereby the medium P is conveyed downward.

[0044] An inversion path T4 is connected to the switchback path T3. In the present embodiment, the inversion path T4 is a conveyance path that sequentially passes through the pair of conveyance rollers 33, the pair of conveyance rollers 34, and the pair of conveyance rollers 30 from the branch position K1 and reaches the pair of conveyance rollers 30. The second curved path R2 described above is included in the inversion path T4. The medium P conveyed downward by the pair of conveyance rollers 33 receives a feeding force from the pair of conveyance rollers 33 and the pair of conveyance rollers 34 and reaches the pair of conveyance rollers 30, and is sent to a position facing the line head 12 again by the pair of conveyance rollers 30. That is, the inversion path T4 is a path that conveys the medium P in a conveyance direction including a vertically downward component, and inverses the conveyance direction including a vertically upward component via the second curved path R2 that is convex downward.

[0045] The medium P sent to a position facing the line head 12 again has the second side opposite to the first side on which recording has already been performed facing the line head 12. Thereby, recording by the line head 12 on the second side of the medium P becomes possible. The medium P on which recording has been performed on the second side is discharged from the discharge position A1 or the discharge position A2 described above.

[0046] Hereinafter, with reference to FIGS. 2 to 7, the configuration of the conveyance roller pair 30, which is a main part of the printer 1 of the present embodiment, and the configuration of the second curved path R2, which is the conveyance path from the conveyance roller pair 30 to the conveyance roller pair 31, will be described in detail. As described above, the printer 1 of the present embodiment includes a conveyance roller pair 30 that conveys the medium P, a conveyance roller pair 31 provided on the downstream side in the conveyance path from the conveyance roller pair 30, and a line head 12 provided on the downstream side of the conveyance roller pair 31 in the conveyance path and that records on the medium P by discharging ink. Here, the conveyance roller pair 31 is a rotator that can switch between a first state in which the leading end of the medium P being nipped by the conveyance roller pair 30 passes therethrough and a second state in which the leading end of the medium P being nipped by the conveyance roller pair 30 does not pass therethrough. And it is configured such that the conveyance roller pair 30 can correct the skew conveyance of the medium P by conveying the medium P and abutting it against the conveyance roller pair 30.

[0047] As shown in FIGS. 2 and 3, the conveyance roller pair 30 is composed of a drive roller 60 and a first toothed roller 61 as a driven roller. Here, as shown in FIG. 5, the first toothed roller 61 has a plurality of convex portions 67 on the outer peripheral portion 66 that can be in point contact with the medium P, and is configured such that the medium P can be nipped by the plurality of convex portions 67. And as shown in FIG. 3, when the conveyance path is divided into three regions S1, S2, and S3 in the width direction in the Y-axis direction in the figure, which corresponds to the rotation axis direction of the first toothed roller 61, the conveyance roller pair 30 is arranged only in the central region S2.

[0048] As described above, in the printer 1 of the present embodiment, the conveyance roller pair 30 is arranged only in the central region S2 when the conveyance path is divided into three in the width direction. For this reason, as shown in FIG. 6, the medium P can be rotated with the center C1 of the rotation axis as the nip position that is narrow in the width direction in the central region S2. By setting such a narrow nip range in the width direction, it is possible to easily rotate with the center C1 of the rotation axis as the nip position, and it is possible to effectively correct the skew conveyance of the medium P.

[0049] On the other hand, in a printer equipped with a pair of conveying rollers 610 having a nip range that is wide in the width direction and has been conventionally and generally used as shown in FIG. 7, it is difficult to rotate the nip position of the pair of conveying rollers 610 about the center of the rotation axis. In the printer shown in FIG. 7, the center C2 of the rotation axis when correcting the skew conveyance of the medium P becomes the contact position with the pair of conveying rollers 31. In the printer shown in FIG. 7, depending on the type of the medium P used, etc., since the medium P is nipped across the entire width direction, it is difficult to rotate the medium P with reference to the nip position, and it is difficult for the medium to shift in the width direction due to a strong nip force, and it may be difficult to correct the skew conveyance.

[0050] As described above, in the printer 1 of the present embodiment, the pair of conveying rollers 30 includes a first toothed roller 61 having a convex portion 67 on the outer peripheral portion 66. Note that a configuration in which the medium P is nipped and conveyed by one convex portion 67 makes it easier to rotate the medium P, but if the configuration is such that the medium P is nipped and conveyed by one convex portion 67, the conveying force is likely to decrease. However, in the printer 1 of the present embodiment, since the pair of conveying rollers 30 includes the first toothed roller 61 that nips the medium P with a plurality of convex portions 67, the medium P can be nipped and conveyed by the plurality of convex portions 67 of the first toothed roller 61, and a decrease in the force for conveying the medium P can be suppressed. That is, the printer 1 of the present embodiment can correct the skew conveyance of the medium P without reducing the force for conveying the medium P.

[0051] Here, when the transport roller pair 30 is located downstream of the confluence position of the reverse path T4 and the supply path T1 as in the printer 1 of the present embodiment, when recording is performed on both sides of the medium P, the ink adhering to the medium P may adhere to the transport roller pair 30. However, in the printer 1 of the present embodiment, since the convex portion 67 nips the medium P, for example, when recording is performed on both sides of the medium P, it is difficult for the ink adhering to the medium P to adhere to the transport roller pair 30, and the transport roller pair 30 is not easily soiled with ink. Also, in a general skew correction mechanism, the medium P is often slid in the width direction at the transport roller pair 30 along with skew correction. However, in this embodiment, since the convex portion 67 nips the medium P, the medium P is suppressed from sliding in the width direction, and it is possible to suppress the ink adhering to the medium P from adhering to the transport roller pair 30 due to the medium P sliding in the width direction.

[0052] In the printer 1 of the present embodiment, a transport roller pair 31 is provided as a rotator capable of switching between a first state in which the leading end of the medium P being nipped by the transport roller pair 30 passes through and a second state in which the leading end of the medium P being nipped by the transport roller pair 30 does not pass through. However, as such a rotator, a configuration other than the transport roller pair 31 as in the present embodiment may be provided. For example, as an example of the rotator, in addition to a configuration in which the medium P is abutted against the nip portion of the rotators constituting the roller pair like the transport roller pair 31 of the present embodiment, a configuration in which the medium P is abutted against a gate that moves in synchronization with the roller pair, or a configuration including a roller pair capable of temporarily reverse transporting the medium P can be adopted.

[0053] In addition, when the rotating body is composed of a pair of rollers having a rotation axis in the width direction as in the printer 1 of the present embodiment, the nip width in the width direction of the conveying roller pair 30 is preferably 0.25 times or less of the nip width in the width direction of the conveying roller pair 31 which is the rotating body. By adopting such a configuration, the effect of skew correction can be particularly improved. Note that, by setting the nip width in the width direction of the conveying roller pair 30 to 0.20 times or less of the nip width in the width direction of the conveying roller pair 31 which is the rotating body, the effect of skew correction can be further improved.

[0054] As shown in FIG. 3, the conveying roller pair 30 includes two driving rollers 60 and two first toothed rollers 61. The two driving rollers 60 have the same shape, and the two first toothed rollers 61 also have the same shape. Further, as shown in FIG. 5, the first toothed roller 61 is composed of a rotation shaft 62, a plurality of annular holders 64 fitted to the rotation shaft 62, and a plurality of annular tooth members 65 fitted to the rotation shaft 62. The tooth member 65 has a plurality of convex portions 67 along the outer peripheral portion 66. The holders 64 and the tooth members 65 are alternately fitted to the rotation shaft 62, and one first toothed roller 61 has four tooth members 65. That is, the first toothed roller 61 includes a plurality of tooth members 65 having a plurality of convex portions 67 along the outer peripheral portion 66 in the width direction.

[0055] As described above, since the first toothed roller 61 includes a plurality of toothed members 65 having a plurality of convex portions 67 along the outer peripheral portion 66 in the width direction, even if the number of convex portions 67 of each toothed member 65 is reduced, the number of convex portions 67 of the entire first toothed roller 61 can be increased. By reducing the number of convex portions 67 of each toothed member 65, it becomes possible to facilitate the manufacture of the toothed member 65 and reduce the cost. In addition, by providing a plurality of toothed members 65, the number of convex portions 67 of the entire first toothed roller 61 can be increased, so that a decrease in the force for conveying the medium P can be effectively suppressed. In the present embodiment, two first toothed rollers 61 are provided, and each first toothed roller 61 is provided with four toothed members 65. And the convex portions 67 are arranged such that one convex portion 67 of each toothed member 65 bites the medium P.

[0056] As shown in FIG. 2, in the printer 1 of the present embodiment, the transport roller pair 31 is composed of a drive roller 68 and a second toothed roller 69 as a driven roller. The second toothed roller 69 has the same configuration as the first toothed roller 61. Here, it is preferable that the outer diameter of the first toothed roller 61 is equal to or greater than the outer diameter of the second toothed roller 69.

[0057] Making the outer diameter of the first toothed roller 61 equal to or greater than the outer diameter of the second toothed roller 69 corresponds to increasing the outer diameter of the first toothed roller 61. By increasing the outer diameter of the first toothed roller 61, the time from when one convex portion 67 bites the medium P until the next time the medium P is bitten can be lengthened. By increasing the outer diameter of the first toothed roller 61, for example, when recording is performed on both sides of the medium P and the first toothed roller 61 contacts the medium P with ink attached, the time from when one convex portion 67 contacts the medium P until the next time it contacts the medium P can be lengthened. By lengthening this time, this time can be made a sufficient ink drying time, and reattachment of the ink attached to the convex portion 67 to the medium P can be suppressed.

[0058] As described above, in the printer 1 of the present embodiment, the conveyance path includes a supply path T1 that supplies the medium P placed on the first medium cassette 3, the second medium cassette 4, the third medium cassette 5, and the fourth medium cassette 6, which are placement portions of the medium P, to the line head 12, and a reverse path T4 that reverses the front and back of the medium P recorded by the line head 12 and supplies the medium P with the front and back reversed to the supply path T1. Here, the pair of conveyance rollers 30 and the pair of conveyance rollers 31 are arranged in the supply path T1. As shown in FIG. 2, the supply path T1 includes a vertically upward path T1A that conveys the medium P vertically upward between the pair of conveyance rollers 30 and the pair of conveyance rollers 31. Therefore, the printer 1 of the present embodiment can reduce the supply path T1 in the horizontal direction, and the installation area of the printer 1 can be reduced. Although the pair of conveyance rollers 30 requires a large conveyance force because it includes the vertically upward path T1A, as described above, since the pair of conveyance rollers 30 includes the first toothed roller 61, the medium P can be bitten by the plurality of convex portions 67 of the first toothed roller 61 and conveyed, and the medium P can be conveyed with a large conveyance force.

[0059] Also, as shown in FIGS. 2 and 4, the supply path T includes a second curved path R2 that is a curved path between the pair of conveyance rollers 30 and the pair of conveyance rollers 31. And in the second curved path R2, a deflection space 80 that expands outward is provided to allow the deflection of the medium P being conveyed in the second curved path R2. Therefore, the printer 1 of the present embodiment can utilize the deflection space 80 during skew correction, and can effectively correct the skew conveyance of the medium P by utilizing the restoring force accompanying the deflection of the medium P.

[0060] Also, as shown in FIGS. 2 and 4, a fixed end 71 is provided on the supply path T upstream of the deflection space 80, and a free end 72 is provided downstream of the fixed end 71, so that a swing member 70 that can swing with the fixed end 71 as a swing axis is provided. Here, as shown in FIGS. 2 and 4, the deflection space 80 extends outward beyond the swing member 70.

[0061] When transporting the medium P, if the medium P bends too much outward, there is a risk of conveyance failure. However, the printer 1 of the present embodiment can suppress the medium P from bending too much outward when transporting the medium P by swinging the swing member 70. Further, by swinging the swing member 70, the medium P can be sufficiently bent during skew correction. In addition, since the risk of conveyance failure can be reduced even if a large bending space 80 is provided by providing the swing member 70, the skew conveyance of the medium P can be effectively corrected even when using a medium P such as thick paper for which skew correction is generally difficult.

[0062] Also, as shown in FIG. 1, the line head 12 is located on the same side as the outside of the second curved path R2 on the side where the bending space 80 is provided with respect to the conveyance path of the medium P. On the other hand, the first toothed roller 61 is located on the same side as the inside of the second curved path R2 with respect to the conveyance path of the medium P. Since the line head 12 is located on the same side as the outside of the second curved path R2 with respect to the conveyance path, there is no need to provide the line head 12 in the region surrounded by the supply path T1 and the reverse path T4, so there is no need to make the region surrounded by the supply path T1 and the reverse path T4 wide, and the printer 1 can be miniaturized. Further, when recording on both sides of the medium P, the medium P supplied to the supply path T1 through the reverse path T4 has the surface to which ink adheres swollen and curved due to recording by the line head 12, and is likely to cause conveyance failure. However, the printer 1 of the present embodiment can effectively suppress the conveyance failure of the medium P that is likely to bend by the swing member 70. Note that the "same side as the outside of the second curved path R2" includes, in addition to the "outer portion of the second curved path R2", the "same side as the outer portion of the second curved path R2" in the region other than the second curved path R2 in the conveyance path. Similarly, the "same side as the inside of the second curved path R2" includes, in addition to the "inner portion of the second curved path R2", the "same side as the inner portion of the second curved path R2" in the region other than the second curved path R2 in the conveyance path.

[0063] Note that the nip force of the first toothed roller 61 on the medium P is preferably 3.0 N or more and 6.0 N or less. By adopting such a configuration, it is possible to suppress a decrease in the transportability of the medium P and, for example, suppress the adhesion of ink to the first toothed roller 61 when recording on both sides of the medium P. Note that by setting the nip force of the first toothed roller 61 on the medium P to 3.5 N or more and 5.0 N or less, it is possible to further improve the effect of suppressing the adhesion of ink to the first toothed roller 61 when recording on both sides of the medium P while suppressing a decrease in the transportability of the medium P.

[0064] Next, with reference to FIGS. 8 to 11, the first toothed roller 61 applicable to the printer 1 of the present invention will be described in detail particularly from the viewpoint of the toothed member 65. Here, FIG. 8 is a diagram showing the toothed member 65 of the printer 1 represented by FIGS. 1 to 7 above, and FIGS. 9 and 10 are diagrams showing the toothed member 65 of a printer according to an embodiment of the present invention different from the printer 1 above. Note that the printers of FIGS. 9 and 10 have the same configuration as the printer 1 above except for the first toothed roller 61. Further, FIG. 11 is a schematic diagram for explaining the convex portion 67.

[0065] As shown in FIG. 5, the printer 1 represented by FIGS. 1 to 7 includes a first toothed roller 61 having four toothed members 65 per one. Here, the four toothed members 65 each have the same configuration, and are arranged such that the phases of the respective convex portions 67 are shifted in the circumferential direction. FIG. 8 is an enlarged view of the peripheral portion of the convex portion 67 of the toothed member 65 of the printer 1 represented by FIGS. 1 to 7.

[0066] Here, when viewed along the width direction as shown in FIG. 8, the tooth member 65 has an angle x of 80° formed by the tip 67a of the convex portion 67. The tooth member 65 shown in FIG. 8 has 37 convex portions 67 per sheet. Note that the tip 67a of the convex portion 67 in the present embodiment is rounded in an arc shape with a radius of 0.03 mm, but it may be pointed. The angle x formed by the tip 67a of the convex portion 67 is the angle formed by the sides of the convex portion 67 at the biting-in position ya, which will be described later, when the convex portion 67 is entirely rounded. In other words, it is the angle formed by the sides when the sides of the convex portion 67 are virtually extended.

[0067] On the other hand, the first toothed roller 61 of the printer shown in FIGS. 9 and 10 includes a first toothed roller 61 having five tooth members 65 per one. Here, the five tooth members 65 each have the same configuration, and are arranged such that the phases of the respective convex portions 67 are shifted in the circumferential direction, similar to the first toothed roller 61 of the printer 1 shown in FIGS. 1 to 7. FIG. 9 is an enlarged view of the peripheral portion of the convex portion 67 of the tooth member 65 of the printer.

[0068] Here, when viewed along the width direction as shown in FIG. 9, the tooth member 65 has an angle x of 60° formed by the tip 67a of the convex portion 67. The tooth member 65 shown in FIG. 9 has 57 convex portions 67 per sheet, and the number of convex portions 67 per sheet is larger than that of the tooth member 65 shown in FIG. 8. This is because the angle x formed by the tip 67a of the convex portion 67 is small, so that the interval between adjacent convex portions 67 in the circumferential direction can be shortened. Note that the tip 67a of the convex portion 67 in the present embodiment is rounded in an arc shape with a radius of 0.05 mm.

[0069] The tooth member 65 secures the conveying force with the medium P by pressing the convex portion 67 against the conveyed medium P and causing the periphery of the tip portion 67a to bite into the medium P. The biting position ya in FIGS. 10 and 11 corresponds to the position on the surface of the medium P when the convex portion 67 is pressed against the conveyed medium P. In the tooth member 65 of the printer represented in FIGS. 9 and 10, the thickness t of the convex portion 67 at the biting position ya is 0.05 mm. On the other hand, in the tooth member 65 represented in FIG. 8, the thickness t of the convex portion 67 at the biting position ya is 0.10 mm, which is thicker overall than the tooth member 65 represented in FIG. 9. For this reason, between the first toothed roller 61 of the printer 1 represented in FIGS. 1 to 7 and the first toothed roller 61 of the printer represented in FIGS. 9 and 10, the thickness in the width direction is substantially the same, but the first toothed roller 61 per printer represented in FIGS. 1 to 7 includes four tooth members 65, while the first toothed roller 61 per printer represented in FIGS. 9 and 10 includes five tooth members 65. Here, as represented in FIG. 10, for the tooth member 65 of the printer represented in FIGS. 9 and 10, the thickness tb of the region other than the periphery of the tip portion 67a of the convex portion 67 is 0.20 mm, and it becomes thinner as it approaches the tip portion 67a of the thickness ta. However, it is not limited to such a configuration. In the configuration of the present embodiment, the thickness t of the convex portion 67 corresponds to the thickness ta of the tip portion 67a.

[0070] If the force pressing the convex portion 67 against the conveyed medium P is strong, for example, when recording on the second side in the case of recording on both sides of the medium P, the ink ejected onto the first side adheres to the convex portion 67, and there is a risk that the ink will be transferred to the medium P. For this reason, the tooth member 65 needs to secure the conveying force with the medium P without making the force pressing the convex portion 67 too strong. Therefore, it is conceivable to reduce the contact area between the medium P and the convex portion 67. By reducing the contact area between the medium P and the convex portion 67, it is possible to secure the conveying force without making the force pressing the convex portion 67 against the medium P too strong. As a result, the medium P can be conveyed appropriately, and ink transfer to the medium P can be reduced.

[0071] Here, a method for calculating the contact area between the medium P and the convex portion 67 will be described with reference to FIG. 11. The contact area is calculated by the length y of the convex portion 67 in contact with the medium P at the penetration position ya where the penetration amount e is bitten from the tip portion 67a and the thickness t of the convex portion 67. In FIG. 11, the distance l between the intersection point p in the tangential direction extended from the tip portion 67a and the center of the arc of the tip portion 67a is expressed by the following equation. Here, x is the angle formed by the tip portion 67a of the convex portion 67 as described above. l = r / sin(x / 2)

[0072] According to the above equation, the distance a between the intersection point p and the penetration position ya is expressed by the following equation. a = l - r + e = r / sin(x / 2) - r + e

[0073] According to the above equation, the length y at the penetration position ya is expressed by the following equation. y = 2 · a · tan(x / 2) = 2 · (r / sin(x / 2) - r + e) · tan(x / 2)

[0074] Here, as described above, when the thickness of the convex portion 67 is t, the contact area d of the convex portion 67 per sheet is expressed by the following equation. d = t · y = 2 · t · (r / sin(x / 2) - r + e) · tan(x / 2)

[0075] As described above, in the first toothed roller 61 of the printer represented in FIGS. 9 and 10, as represented in FIG. 9, the angle x formed by the tip 67a of the convex portion 67 when viewed along the width direction is 60°. Here, it is preferable that the angle x is 60° or more and 70° or less. When the number of convex portions 67 increases, foreign substances such as ink are likely to adhere to the toothed member 65. However, by setting the angle formed by the tip 67a of the convex portion 67 to 60° or more, it is possible to suppress an excessive increase in the number of convex portions 67 and suppress the adhesion of foreign substances such as ink to the toothed member 65. Also, if the number of convex portions per first toothed roller becomes too small, the conveying force of the medium P decreases. However, by setting the angle formed by the tip 67a of the convex portion 67 to 70° or less, the interval between adjacent convex portions 67 in the circumferential direction can be shortened in each toothed member 65, suppressing an excessive decrease in the number of convex portions 67 per toothed member 65 and suppressing a decrease in the conveying force of the medium P. Note that the first toothed roller 61 having the toothed member 65 represented in FIG. 9 where the angle x is 60° has a significantly greater conveying force for the medium P than the first toothed roller 61 having the toothed member 65 represented in FIG. 8 where the angle x is 80°.

[0076] Also, when attempting to set the angle formed by the tip 67a of the convex portion 67 to a specific angle or less, the distance from the tip 67a to a valley portion 67b (not shown) increases, making it easier for ink to accumulate. If ink accumulates in the valley portion 67b, it becomes a factor in ink transfer to the medium P. The specific angle here is, for example, 50°. Therefore, by setting the angle formed by the tip 67a of the convex portion 67 to 60° or more, ink transfer can be reduced. Note that the first toothed roller 61 having the toothed member 65 represented in FIG. 9 where the angle x is 60° has significantly less ink transfer to the medium P than the first toothed roller 61 having a toothed member (not shown) where the angle x is 50°.

[0077] In this embodiment, the tooth member 65 is formed by pressing. However, by forming the tooth member 65 by etching, the number of convex portions 67 can be increased even when the angle x is greater than 70°. However, in that case, etching or the like is required. For example, if the tooth member 65 is formed by etching, the cost of the tooth member 65 will increase. Also, by increasing the number of tooth members 65, it is possible to suppress the number of convex portions 67 per one first toothed roller 61 from becoming too small. However, increasing the number of tooth members 65 may lead to a cost increase, and there is a possibility that the thickness of the first toothed roller 61 in the width direction becomes thick, and it may not be possible to effectively correct the skew conveyance of the medium P.

[0078] As described above, in the first toothed roller 61 of the printer shown in FIGS. 9 and 10, the thickness t in the width direction of the convex portion 67 is 0.05 mm. Here, it is preferable that the thickness t is 0.05 mm or more and 0.10 mm or less. It is difficult to simply make the thickness t in the width direction of the convex portion 67 thin. If it is made thin, it will cause a cost increase. However, by setting the thickness t in the width direction of the convex portion 67 to 0.05 mm or more, it can be easily configured by pressing or the like, and the tooth member 65 can be easily configured at low cost. Also, if the thickness t in the width direction of the convex portion 67 is made too thick, foreign matters such as ink are likely to adhere to the convex portion 67, and there is a risk that the foreign matter adhering to the convex portion 67 is transferred to the medium P. However, by setting the thickness in the width direction of the convex portion 67 to 0.10 mm or less, it is possible to suppress the thickness t in the width direction of the convex portion 67 from becoming too thick, and it is possible to reduce the risk of foreign matter adhering to the convex portion 67 being transferred to the medium P.

[0079] The present invention is not limited to the embodiments described above, and various modifications are possible within the scope of the invention described in the claims, and it goes without saying that those are also included in the scope of the present invention.

Explanation of reference numerals

[0080] 1... Inkjet printer (printer, recording device), 2... Apparatus main body, 3... First medium cassette (placement section), 4... Second medium cassette (placement section), 5... Third medium cassette (placement section), 6... Fourth medium cassette (placement section), 7... Supply tray, 8... Discharge tray, 10... Ink storage section, 11... Waste liquid storage section, 12... Line head (recording section), 13... Conveyor belt, 14... Pulley, 15... Pulley, 18... Pair of external conveyance rollers, 19... Supply roller, 20... Separation roller, 21... Pickup roller, 22... Pickup roller, 23... Pickup roller, 24... Pickup roller, 25... Feed roller pair, 26... Feed roller pair, 27... Feed roller pair, 28... Feed roller pair, 29... Conveyor roller pair, 30... Conveyor roller pair, 31... Conveyor roller pair (rotating body), 32... Conveyor roller pair, 33... Conveyor roller pair, 34... Conveyor roller pair, 37... Conveyor roller pair, 38... Conveyor roller pair, 39... Conveyor roller pair, 41... Flap, 42... Flap, 60... Driving roller, 61... First toothed roller, 62... Rotation axis, 64... Holder, 65... Toothed member, 66... Outer peripheral portion, 67... Protrusion, 67a... Tip portion, 67b... Valley portion, 68... Driving roller, 69... Second toothed roller, 70... Oscillating member, 71... Fixed end, 72... Free end, 80... Deflection space, 130... Conveyor roller pair, 131... Conveyor roller pair, 132... Conveyor roller pair, P... Medium, R1... First curved path, R2... Second curved path, S1... Region, S2... Region, S3... Region, T1... Supply path, T1A... Vertically upward path, T2... Conveyance path during recording, T3... Switchback path, T4... Reversal path

Claims

1. A pair of conveying rollers for conveying a medium, A rotating body provided downstream of the pair of conveying rollers in the conveying path of the medium, capable of switching between a first state in which the leading end of the medium in the nip by the pair of conveying rollers passes through and a second state in which the leading end of the medium in the nip by the pair of conveying rollers does not pass through, A recording unit provided downstream of the rotating body in the conveying path, for performing recording on the medium by discharging a liquid, comprising The pair of conveying rollers includes a first toothed roller having a plurality of convex portions on its outer peripheral portion that can be in point contact with the medium, and nipping the medium by the plurality of convex portions, A recording apparatus, characterized in that it is arranged only in a central region when the conveying path is divided into three in a width direction corresponding to the rotation axis direction of the first toothed roller.

2. In the recording apparatus according to Claim 1, the first toothed roller is characterized by including a plurality of tooth members having a plurality of the convex portions along the outer peripheral portion in the width direction.

3. In the recording apparatus according to Claim 1 or Claim 2, the rotating body includes a second toothed roller having a plurality of convex portions on its outer peripheral portion that can be in point contact with the medium, A recording apparatus, characterized in that the outer diameter of the first toothed roller is greater than or equal to the outer diameter of the second toothed roller.

4. In the recording apparatus according to any one of Claims 1 to 3, the conveying path includes a supply path for supplying the medium placed on the placement portion to the recording unit, and a reversing path for reversing the front and back of the medium recorded by the recording unit and supplying the medium with the front and back reversed to the supply path, the pair of conveying rollers and the rotating body are arranged in the supply path, The recording apparatus is characterized in that the supply path includes a vertically upward path that conveys the medium vertically upward between the pair of conveying rollers and the rotating body.

5. In the recording apparatus according to claim 4, the supply path includes a curved path between the pair of conveying rollers and the rotating body, and the curved path is provided with a deflection space that expands outward to allow deflection of the medium being conveyed through the curved path. The recording apparatus is characterized by this.

6. In the recording apparatus according to claim 5, the supply path is provided with a fixed end upstream of the deflection space and a free end downstream of the fixed end, and includes a swing member that can swing with the fixed end as a swing axis, and the deflection space extends wider to the outside than the swing member. The recording apparatus is characterized by this.

7. In the recording apparatus according to claim 6, the swing member is characterized in that the free end is provided downstream of the fixed end and also downstream of the deep part of the deflection space. The recording apparatus is characterized by this.

8. In the recording apparatus according to any one of claims 5 to 7, the recording unit is located on the same side as the outside with respect to the conveyance path, and the first toothed roller is located on the same side as the inside of the curved path with respect to the conveyance path. The recording apparatus is characterized by this.

9. In the recording apparatus according to any one of claims 1 to 8, the rotating body is composed of a pair of rollers having a rotation axis in the width direction, and the nip width of the pair of conveying rollers in the width direction is 0.25 times or less of the nip width of the rotating body in the width direction. The recording apparatus is characterized by this.

10. In the recording apparatus according to any one of claims 1 to 9, The nip force of the first toothed roller against the medium is 3.0 N or more and 6.0 N or less, and the recording apparatus is characterized by this.

11. In the recording apparatus according to any one of Claims 1 to 10, The angle formed by the tip of the convex portion as viewed along the width direction is 60° or more and 70° or less, and the recording apparatus is characterized by this.

12. In the recording apparatus according to Claim 11, The thickness of the convex portion in the width direction is 0.05 mm or more and 0.10 mm or less, and the recording apparatus is characterized by this.

Images