Printing device

Abstract

The present invention provides a printing apparatus that makes it easy to remove the roll of media. When a user-operated disassembly operation is performed on the roll (RP) from the media holding section (42) while the media is positioned downstream of the first roller pair (51) in the forward direction at the front end (PA), the printing apparatus (1) performs a first reverse conveying operation to rotate the first drive roller (51a) in the second direction by moving the media in the opposite direction by an amount corresponding to a first distance, performs a first forward conveying operation to rotate the first drive roller (51a) in the first direction by moving the planetary gear (132) from the first position to the second position, and performs a second reverse conveying operation to rotate the first drive roller (51a) in the second direction by moving the media in the opposite direction by an amount corresponding to a second distance.

Description

Technical Field

[0001] This invention relates to a printing apparatus. Background Technology

[0002] Various printing apparatuses have been used throughout history. Among them, for example, there are printing apparatuses that can be used to wind long strips of media into a roll.

[0003] In the printing apparatus described in Patent Document 1, the driving force of the drive source is transmitted to the conveyor roller pair to make it rotate in the forward direction during feeding of the medium, and planetary gears are used to switch the driving force of the drive source in the reverse direction by driving both the conveyor roller pair and the support shaft of the roll body in the reverse direction during rewinding of the medium. However, in such a printing apparatus, although the medium is rewound during the roll body disassembly operation performed by the user, the rewinding amount is a fixed length regardless of the remaining amount of medium constituting the roll body. Therefore, due to deviations in the type of medium, the remaining amount of medium, the weight of the roll body, the degree of media curling, etc., the position of the leading edge of the medium after rewinding will be deviated, and even after the medium is rewound, there may be a situation where the leading edge of the medium remains clamped by the conveyor roller pair. The reason for not allowing the medium to be rewound too much, but rather to be rewound to a certain length, is that if the medium is rewound too much, the state of applying strong clamping pressure to the medium from the rollers in the conveying path will become longer, which may cause the medium to be strongly curled or damaged. By setting it to a certain length, control becomes simpler.

[0004] Furthermore, after the media has been rewound, when the user places the next roll on the support shaft and allows the leading edge of the media to pass through the conveyor path, it becomes important to allow the support shaft to rotate freely to improve user operability. However, to allow the support shaft to rotate freely, a temporary forward rotation is required, achieved by releasing the planetary gears. Moreover, even if the leading edge of the rewound media is positioned upstream in the forward direction compared to the conveyor rollers, the conveyor rollers may still encircle the leading edge of the media due to the forward conveying of the roll paper accompanying the planetary gear release, potentially preventing the user from removing the roll clamped by the conveyor rollers.

[0005] Patent document 1: Japanese Patent Application Publication No. 2014-73595. Summary of the Invention

[0006] The printing apparatus of the present invention, which solves the above-mentioned problems, is characterized by comprising: a media holding unit including a first shaft, the first shaft holding a roll of elongated media wound into a cylindrical shape in a rotatable manner; a transport path for transporting the media; a printing unit opposite to the transported media; a first roller pair having a first drive roller and a first driven roller, and rotatable in a manner capable of transporting the media in a forward direction and in a reverse direction opposite to the forward direction; a first shaft gear disposed on the first shaft and causing the first shaft to rotate; and a first roller gear disposed on a second shaft that rotatably supports the first drive roller and causes the first drive roller to rotate. The drive unit generates a driving force that causes the first drive roller to rotate in a first direction and a second direction opposite to the first direction; a power transmission mechanism that, when the drive unit rotates the first drive roller in the second direction, transmits the driving force of the drive unit as a rotational force in the direction that causes the medium to rewind toward the medium holding part; a control unit that controls the drive unit, the power transmission mechanism having a sun gear, planetary gears and a rotating component, the sun gear rotating by the driving force of the drive unit and transmitting the driving force of the drive unit to the first roller gear, the planetary gears being able to rotate in the direction of rotation when meshed with the sun gear. The rotating component moves in a circle around the rotation center of the sun gear while holding the planetary gear. The rotating component rotates in a manner such that, when the drive unit rotates the first drive roller in the second direction, it is in a first position where the planetary gear transmits the driving force of the drive unit to the first shaft gear; and it rotates in a second position where, when the drive unit rotates the first drive roller in the first direction, the planetary gear does not transmit the driving force of the drive unit to the first shaft gear. The control unit controls the drive unit when it is at the front end of the medium. When the user performs a disassembly operation from the roll body of the media holding section while the roll is located downstream of the first roller pair in the positive direction, a first reverse conveying operation is performed, that is, the first drive roller is rotated in the second direction by moving the media in the opposite direction by an amount corresponding to a first distance, and a first forward conveying operation is performed, that is, the first drive roller is rotated in the first direction by moving the planetary gear from the first position to the second position, and a second reverse conveying operation is performed, that is, the first drive roller is rotated in the second direction by moving the media in the opposite direction by a second distance. Attached Figure Description

[0007] Figure 1 This is a side sectional view illustrating the internal structure of a printing apparatus according to an embodiment of the present invention.

[0008] Figure 2 To indicate Figure 1 The diagram shows a side view of the peripheral structure of the power transmission mechanism of the printing apparatus, and is a diagram showing the state of the rotating component in the first position.

[0009] Figure 3 To indicate Figure 1 A perspective view of the peripheral structure of the power transmission mechanism of the printing apparatus, showing the state of the rotating component in the first position.

[0010] Figure 4 To indicate Figure 1 A side view of a portion of the power transmission mechanism of the printing apparatus, showing the state of the rotating component in the first position.

[0011] Figure 5 To indicate Figure 1 A side view of a portion of the power transmission mechanism of the printing apparatus, showing the state of the rotating component in the second position.

[0012] Figure 6 To indicate Figure 1 A side sectional view of the peripheral structure of the first roller pair and the second roller pair of the printing apparatus.

[0013] Figure 7 In order to be in Figure 1 A flowchart illustrating the disassembly of the roll body in a printing apparatus. Detailed Implementation

[0014] First, a brief description of the present invention will be given.

[0015] The printing apparatus of the first aspect of the present invention for solving the above-mentioned problems is characterized by comprising: a media holding unit including a first shaft, the first shaft holding a roll of elongated media wound into a cylindrical shape in a rotatable manner; a transport path for transporting the media; a printing unit opposite to the transported media; a first roller pair having a first drive roller and a first driven roller, and being rotatable in a manner capable of transporting the media in a forward direction and in a reverse direction opposite to the forward direction; a first shaft gear disposed on the first shaft and causing the first shaft to rotate; and a first roller gear disposed on a second shaft supporting the first drive roller in a rotatable manner and causing the first drive roller to rotate. A drive roller rotates; a drive unit generates a driving force that rotates the first drive roller in a first direction and a second direction opposite to the first direction; a power transmission mechanism, which, when the drive unit rotates the first drive roller in the second direction, transmits the driving force of the drive unit as a rotational force in the direction that causes the medium to rewind toward the medium holding part; a control unit controls the drive unit, the power transmission mechanism having a sun gear, planetary gears, and a rotating component, the sun gear rotating by the driving force of the drive unit and transmitting the driving force of the drive unit to the first roller gear, the planetary gears being able to rotate in a certain direction when meshed with the sun gear. The rotating component moves in a circle around the rotation center of the sun gear. While holding the planetary gear, the rotating component can rotate around the rotation center of the sun gear. The rotating component rotates in a first position where, when the drive unit rotates the first drive roller in the second direction, the planetary gear transmits the driving force of the drive unit to the first shaft gear. It also rotates in a second position where, when the drive unit rotates the first drive roller in the first direction, the planetary gear does not transmit the driving force of the drive unit to the first shaft gear. The control unit controls the drive unit. When in front of the medium... When the user performs a disassembly operation from the roll body of the media holding section while the roll is located downstream of the first roller pair in the positive direction, a first reverse conveying operation is performed, that is, the first drive roller is rotated in the second direction by moving the media in the opposite direction by an amount corresponding to a first distance, and a first forward conveying operation is performed, that is, the first drive roller is rotated in the first direction by moving the planetary gear from the first position to the second position, and a second reverse conveying operation is performed, that is, the first drive roller is rotated in the second direction by moving the media in the opposite direction by a second distance.

[0016] According to this method, when the user performs a disassembly operation of the roll body from the media holding section while the media is positioned downstream of the first roller pair in the forward direction, a first reverse conveying operation is performed to rotate the first drive roller in the second direction by moving the media in the opposite direction by an amount corresponding to a first distance. Subsequently, a first forward conveying operation is performed to rotate the first drive roller in the first direction by moving the planetary gear from the first position to the second position. Subsequently, a second reverse conveying operation is performed to rotate the first drive roller in the second direction by moving the media in the opposite direction by a second distance. By performing such operations, the situation where the first roller pair and other conveying roller pairs wind up the media's leading edge, making it impossible for the user to disassemble the roll body, can be suppressed. Therefore, removing the media roll body becomes easier.

[0017] The printing apparatus of the second aspect of the present invention is characterized in that, in a manner subordinate to the first aspect, it includes a detection unit disposed on the upstream side of the transport path compared to the first roller pair in the forward direction, and is capable of detecting whether the medium is located at a predetermined position in the transport path. When the control unit detects that the medium is located at the predetermined position after the completion of the first reverse transport operation, the control unit performs the second reverse transport operation.

[0018] According to this method, a detection unit is provided that can detect whether the medium is located at a predetermined position in the conveying path, compared to the first roller pair in the forward direction and on the upstream side of the conveying path. A second reverse conveying operation is performed when the detection unit detects that the medium is at the predetermined position after the first reverse conveying operation is completed. By performing such an operation, the second reverse conveying operation can be performed only when the detection unit detects the medium. That is, the second reverse conveying operation can be performed only when needed, thus reducing the time for removing the roll of medium and saving power.

[0019] The third-party printing apparatus of the present invention is characterized in that, in a manner subordinate to the first or second method, it includes a second roller pair having a second drive roller and a second driven roller, and is rotated in a manner that conveys the medium in the forward direction and the reverse direction. The second roller pair is located upstream of the first roller pair in the forward direction, and is configured such that, in the event that the medium curls, the curled portion, which is the part where the curling occurs, can be bent in a direction that corrects the curled portion.

[0020] According to this method, a second roller pair is provided, which is located upstream of the first roller pair in the forward direction. When curling occurs on the medium, the curled portion, which is the curled part, is clamped, thereby causing the medium to bend in the direction of correcting the curled portion. By configuring it in this way, correction that reduces curling can be performed when the medium curls.

[0021] The printing apparatus of the fourth aspect of the present invention is characterized in that, in a mode subordinate to the third aspect, the control unit releases the contact state of the second roller pair after the completion of the second reverse conveying operation.

[0022] According to this method, after the second reverse conveying action is completed, the contact state of the second roller pair is released. By performing such an action, when the front end of the medium is inserted into the conveying path along with the installation of the next roll body, the front end of the medium will not be hooked on the second roller pair, which is upstream in the positive direction compared to the first roller pair, thereby ensuring good operability when installing the roll body.

[0023] The printing apparatus of the fifth aspect of the present invention is characterized in that, in a manner subordinate to the second aspect, the detection unit performs a detection action on whether the medium is located at the predetermined position after the completion of the first forward conveying operation.

[0024] According to this method, the detection unit performs a detection action to determine whether the medium is at a predetermined position after the first forward conveying operation is completed. By performing such an operation, the second reverse conveying operation can be performed only when needed, thereby reducing the time for removing the roll of medium and saving power.

[0025] Hereinafter, embodiments of the present invention will be specifically described with reference to the accompanying drawings. First, referring to... Figure 1 The outline of a printing apparatus 1 according to one embodiment of the present invention will be described below. The printing apparatus 1 is, for example, an inkjet printer that prints by ejecting ink onto a medium. In the coordinate system shown in the drawings, it is assumed that the printing apparatus 1 is placed on a horizontal plane, and three mutually orthogonal imaginary axes are designated as the X-axis, Y-axis, and Z-axis. The Y-axis is an axis parallel to the front-back direction of the printing apparatus 1, and the front end of the arrow representing the Y-axis is designated as "front". The X-axis is an axis parallel to the left-right direction of the printing apparatus 1, and the front end of the arrow representing the X-axis is designated as "right". The Z-axis is an imaginary axis parallel to the vertical direction, and the front end of the arrow representing the Z-axis is designated as "up".

[0026] like Figure 1As shown, the printing apparatus 1 includes a housing 2. Inside the housing 2 are a roll paper storage section 40 for storing roll paper RP as a medium, a sheet paper storage section 60 for storing sheet paper SP as a medium other than roll paper RP, and a printing section 20 capable of printing roll paper RP supplied from the roll paper storage section 40 and sheet paper SP supplied from the sheet paper storage section 60.

[0027] The printing unit 20 includes a head 22 with a nozzle that ejects ink toward a medium, and a carriage 21 that mounts the head 22. Furthermore, the printing unit 20 is configured to allow the carriage 21 to reciprocate along the X-axis. A support portion 25 is provided opposite the head 22 to support the medium. The head 22 ejects ink while reciprocating in the width direction B together with the carriage 21, thereby printing on the medium supported by the support portion 25. In this embodiment, a serial head configuration where the head 22 reciprocates in the width direction is illustrated as the printing unit 20, but a row head configuration where the heads extend in the width direction and are fixedly arranged is also possible.

[0028] Inside the housing 2, there is a transport path 30 for conveying the medium and a cutting section 27 for cutting the medium printed by the printing section 20. The transport path 30 has a supply path 30a and a reversing path 30b located upstream of the support section 25, and a discharge path 30c located downstream of the support section 25. Furthermore, the supply path 30a has a roll paper supply path 30R for supplying a roll of paper RP as an example of the medium, and a sheet paper supply path 30S for supplying a single sheet of paper SP as an example of the medium.

[0029] Supply path 30a is a path connecting the roll paper supply path 30R to the support section 25. Upstream of supply path 30a, a roll paper confluence point P2 is provided, merging with the roll paper supply path 30R. Downstream of supply path 30a, a branch point P1 is provided, branching off from supply path 30a when the medium is conveyed from downstream to upstream. Reversing path 30b is a path connecting branch point P1 to roll paper confluence point P2. Between roll paper confluence point P2 and branch point P1 in supply path 30a, a sheet paper confluence point P3 is provided, merging with the sheet paper supply path 30S.

[0030] A discharge port 14 for discharging the printed medium is provided on the front surface of the housing 2. The discharge path 30c is a path connecting the support portion 25 to the discharge port 14. At the middle of the discharge path 30c, a cutting portion 27 is provided to cut off the medium printed by the printing portion 20.

[0031] A conveying section 31 is provided in the conveying path 30 to convey the medium supplied to the conveying path 30. In the supply path 30a, the conveying section 31, starting from upstream, includes an intermediate roller 32, a plurality of driven rollers 33 disposed on the outer periphery of the intermediate roller 32, and an upstream conveying roller pair 34. The driven rollers 33 are rotatably disposed and rotate drivenly while sandwiching the medium between themselves and the intermediate roller 32. In the discharge path 30c, the conveying section 31, starting from upstream, includes a downstream conveying roller pair 35, a roller pair 36, and a roller pair 37. The roller pair 36 is located upstream of the cutting section 27, and the roller pair 37 is located downstream of the cutting section 27.

[0032] The intermediate roller 32, driven roller 33, upstream conveying roller pair 34, downstream conveying roller pair 35, roller pair 36, and roller pair 37 convey the medium by rotating while the medium is being held between them. The medium is conveyed downstream from the upstream direction (A) by forward drive of the conveying unit 31. The medium is conveyed downstream from the upstream direction (opposite to A) by reverse drive of the conveying unit 31.

[0033] The printing apparatus 1 drives the conveyor 31 to rotate forward, transporting the medium from upstream to downstream, and sprays ink from the printing section 20 onto the medium located at the support section 25, thereby printing on the first surface of the medium. The printing apparatus 1 is configured to perform printing on the back side, i.e., the second surface, of the medium. The printing apparatus 1 drives the conveyor 31 to rotate in reverse, transporting the medium after the first surface has been printed in the opposite direction. The medium arrives at the upstream of the supply path 30a from the branch point P1 via the reversing path 30b. The printing apparatus 1 rotates the medium once around the outer circumference of the intermediate roller 32 by driving the conveyor 31 to rotate forward again, thereby reversing the surface of the medium. The printing apparatus 1 transports the medium from upstream to downstream, and sprays ink from the printing section 20 onto the medium located at the support section 25, thereby printing on the second surface of the medium. Thus, printing is performed on both sides of the medium. In addition, when the medium is a roll of paper RP unwound from a roll, printing on the back side is performed on the medium after it has been printed on the surface and cut into individual sheets by the cutting section 27.

[0034] Furthermore, a roll paper storage section 40 is provided inside the housing 2. The roll paper storage section 40 includes a first medium holding section 42 that holds the roll paper RP in a roll state, and the roll paper RP is rotatably supported via a support shaft 41, which serves as a first shaft extending in the X direction of the housing 2. That is, the roll paper RP is supported by the roll paper storage section 40 in a manner that allows it to rotate together with the support shaft 41 around the support shaft 41 as a rotation center. The support shaft 41 is configured to rotate in both the forward and reverse directions. In the roll paper storage section 40, a roll paper transport path 50 is provided at a position opposite to the support member 43 for transporting the roll paper RP unwound from the roll state. The roll paper transport path 50 constitutes a roll paper supply path 30R.

[0035] The roll paper transport path 50 includes a first roll pair 51, a second roll pair 52, a third roll pair 53, and a curved surface 54. The first roll pair 51 has a drive roll 51a driven by a motor and a driven roll 51b opposite to the drive roll 51a and rotating passively with the drive roll 51a. The second roll pair 52 has a drive roll 52a driven by a motor and a driven roll 52b opposite to the drive roll 52a and rotating passively with the drive roll 52a. The third roll pair 53 has a drive roll 53a driven by a motor and a driven roll 53b opposite to the drive roll 53a and rotating passively with the drive roll 53a. The curved surface 54 has a curved surface 54a for sliding of the transported medium. In the roll paper conveying path 50, the medium is conveyed from upstream to downstream in the conveying direction A, i.e., the positive direction, by being pressed against the curved surface 54a of the curved section 54 and driven in the forward rotation by the first roller pair 51, the second roller pair 52 and the third roller pair 53.

[0036] A sheet-fed storage section 60 is provided inside the housing 2. The sheet-fed storage section 60 has a box-shaped tray 61 for storing sheet-fed media SP that are single sheets. The tray 61 has a pair of edge guides 65 that are operated when positioning the sheet-fed SP in the width direction, a stop 64 that is operated when positioning the sheet-fed SP in the front-back direction, and a mounting surface 63 that faces the downstream end of the sheet-fed SP stored in the tray 61 against the pickup roller 72.

[0037] The sheet storage section 60 constitutes part of the sheet supply unit 70 that supplies sheet paper SP to the printing section 20. The sheet supply unit 70 includes the sheet storage section 60, the sheet transport path 71, the pickup roller 72, the deceleration roller 73, the separation roller 74, and the separation member 76. The sheet storage section 60 has a mounting surface 63 that serves as a mounting section capable of holding multiple sheets of sheet paper SP. The pickup roller 72 is a feed roller that is positioned opposite the sheet storage section 60 and feeds the sheet paper SP placed in the sheet storage section 60 in the transport direction A (positive direction) from the sheet storage section 60 to the printing section 20.

[0038] The sheet-fed transport path 71 curves upward from the separating roller 74 and the deceleration roller 73, thus forming the sheet-fed supply path 30S. Sheet-fed transport roller pairs 75, which apply a transport force to the sheet SP, are appropriately spaced along the sheet-fed transport path 71. The sheet SP is transported by rotating the sheet-fed transport roller pairs 75.

[0039] As described above, the printing apparatus 1 of this embodiment includes: a conveying unit 31 that conveys a medium along a conveying path 30 in a conveying direction A (positive direction); and a printing unit 20 that sprays droplets onto the medium conveyed in the conveying path 30 to perform printing. Furthermore, the roll paper supply path 30R includes a curved section 54 having a curved surface 54a, a first roller pair 51, a second roller pair 52, and a third roller pair 53.

[0040] Here, the second roller pair 52 conveys the medium in the conveying path 30 while pressing it against the curved surface 54a of the curved section 54. If the conveying is stopped continuously while the medium is pressed against the curved surface 54a, curling (creases) may occur, forming a downward convex shape along the curved surface 54a. Therefore, the second roller pair 52 is structured such that it can convey the medium while it is curled upwards in the opposite direction to the curved surface 54a.

[0041] If described differently, the printing apparatus 1 of this embodiment includes: a curved section 54 serving as a winding section, which is disposed on the transport path 30 and is capable of winding the medium; and a second roller pair 52 serving as a de-curling roller pair, which is located downstream of the curved section 54 in the transport direction A (positive direction) and is capable of performing a de-curling operation, which involves clamping the curled portion on the medium caused by winding at the curved section 54 to bend it in the direction of correction. Furthermore, as... Figure 1As shown, the printing apparatus 1 of this embodiment includes a control unit 80, which can control the second roller pair 52 to perform a decurving operation and can also control the transport of the medium performed by the transport unit 31. Furthermore, in the printing apparatus 1 of this embodiment, the first roller pair 51 is a main transport roller pair for transporting the medium, and the second roller pair 52 is a transport roller pair primarily for performing a decurving operation.

[0042] As described above, the printing apparatus 1 of this embodiment includes a second roller pair 52, which has a drive roller 52a as a second drive roller and a driven roller 52b as a second driven roller, and rotates to convey the medium in both the forward and reverse directions. Furthermore, the second roller pair 52 is located upstream of the first roller pair 51 in the conveying direction A (forward direction), and is configured such that, in the event of media curling, the curled portion can be clamped, causing the medium to bend in a direction that corrects the curling. By providing such a structure, the printing apparatus 1 of this embodiment can perform correction to reduce curling when the medium curls.

[0043] Below, except Figure 1 In addition, refer to Figures 2 to 6 The printing apparatus 1 of this embodiment will be described in more detail. As described above, the printing apparatus 1 of this embodiment includes: a first media holding unit 42, which includes a support shaft 41 serving as a first axis, the support shaft 41 holding a roll of paper RP, which is a roll body for winding a strip-shaped medium into a roll, in a rotatable manner; a transport path 30 for transporting the medium; and a printing unit 20, which is disposed at a position opposite to the medium transported on the transport path 30. Furthermore, it includes a first roller pair 51, which has a drive roller 51a serving as a first drive roller and a driven roller 51b serving as a first driven roller, and is rotatable in a manner capable of transporting the medium in the forward direction and in the opposite direction.

[0044] like Figures 2 to 5As shown, the printing apparatus 1 of this embodiment includes a power transmission unit 100, which is composed of a drive unit 120 that serves as a motor and a power transmission mechanism 110. The power transmission mechanism 110 is composed of a gear train that transmits the driving force of the drive unit 120. Here, the power transmission unit 100 will be described. The power transmission unit 100 has a gear 121 provided on the rotation shaft of the drive unit 120 and a gear 122 that meshes with the gear 121. The gear 122 meshes with a sun gear 131, the sun gear 131 meshes with a planetary gear 132, and the sun gear 131 and the planetary gear 132 are connected by a rotating member 133. The rotating member 133 is configured to rotate in rotational directions D1 and D2 with respect to the sun gear 131. Figures 2 to 4 This indicates that the rotating component 133 has rotated to its maximum extent in the rotation direction D1. Figure 5 This indicates that the rotating component 133 has rotated to its maximum extent in the rotation direction D2.

[0045] The power transmission mechanism 110 includes: a first power transmission mechanism 140, which transmits power of the drive unit 120 to the support shaft 41, which serves as the first shaft; and a second power transmission mechanism 150, which transmits power of the drive unit 120 to the drive roller 51a of the first roller pair 51 and the drive roller 52a of the second roller pair 52. The first power transmission mechanism 140 includes: a first shaft gear 141, which is mounted on the support shaft 41, which serves as the first shaft; a gear 142, which meshes with the first shaft gear 141; a gear 143, which meshes with the gear 142; a gear 144, which meshes with the gear 143; a gear 145, which meshes with the gear 144; and a gear 146, which meshes with the gear 145. Furthermore, as... Figures 2 to 4 As shown, with the rotating member 133 in its first position where it has rotated to its maximum extent in the rotational direction D1, the planetary gear 132 meshes with the gear 146. On the other hand, for example, like that made by... Figure 5 As shown, when the rotating component 133 is moved from the... Figures 2 to 4 When the planetary gear 132 rotates in the direction of rotation D2 as shown, the meshing between the planetary gear 132 and the gear 146 will be disengaged.

[0046] The second power transmission mechanism 150 includes: a gear 151 disposed on the shaft 520 of the drive roller 52a of the second roller pair 52; a gear 152 meshing with gear 151; a first roller gear 153 meshing with gear 152 and disposed on a second shaft 510 serving as the shaft of the drive roller 51a of the first roller pair 51; a gear 154 meshing with the first roller gear 153; and a gear 155 meshing with gear 154. Furthermore, in... Figures 2 to 4As shown, the rotating component 133 is in a first position where it has rotated to its maximum extent in the rotation direction D1, and as shown... Figure 5 As shown, in any of the states where the rotating component 133 is in the second position where it has rotated to the maximum extent in the rotation direction D2, the gear 155 meshes with the sun gear 131.

[0047] As described above, a first shaft gear 141 is provided on the support shaft 41 to rotate the support shaft 41. Furthermore, a first roller gear 153 is provided on a second shaft 510 that supports the drive roller 51a in a rotatable manner, and is capable of rotating the drive roller 51a, which serves as the first drive roller. Here, the drive unit 120 is able to... Figures 2 to 5 The rotation axis is rotated both clockwise and counterclockwise. In other words, it can generate a force that causes the drive roller 51a to rotate in the first direction (corresponding to the rotation direction D1). Figures 2 to 5 The middle direction is counterclockwise) and the second direction is opposite to the first direction (rotation direction D1) (corresponding to the rotation direction D2, in Figures 2 to 5 The driving force is clockwise. Furthermore, when the drive unit 120 rotates the drive roller 51a in the second direction (rotation direction D2), the power transmission mechanism 110 can transmit the driving force of the drive unit 120 as a rotational force in the direction that causes the medium to roll back toward the first medium holding part 42 (opposite to the conveying direction A) to the support shaft 41, which is the first shaft.

[0048] In detail, when the drive roller 51a rotates in the second direction (rotation direction D2), the first roller gear 153, which is connected to the second shaft 510, which serves as the rotation shaft of the drive roller 51a, also rotates in the second direction (rotation direction D2). While the first roller gear 153 rotates in the second direction (rotation direction D2), gear 154 rotates in the first direction (rotation direction D1). While gear 154 rotates in the first direction (rotation direction D1), gear 155 rotates in the second direction (rotation direction D2). While gear 155 rotates in the second direction (rotation direction D2), the sun gear 131 rotates in the first direction (rotation direction D1), and the rotating component 133 rotates in the rotation direction D1, thereby engaging planetary gear 132 with gear 146.

[0049] When the sun gear 131 rotates in the first direction (rotation direction D1), the planetary gear 132 rotates in the second direction (rotation direction D2). When the planetary gear 132 rotates in the second direction (rotation direction D2), the gear 146 rotates in the first direction (rotation direction D1). When the gear 146 rotates in the first direction (rotation direction D1), the gear 145 rotates in the second direction (rotation direction D2). When the gear 145 rotates in the second direction (rotation direction D2), the gear 144 rotates in the first direction (rotation direction D1). When the gear 144 rotates in the first direction (rotation direction D1), the gear 143 rotates in the second direction (rotation direction D2). When the gear 143 rotates in the second direction (rotation direction D2), the gear 142 rotates in the second direction (rotation direction D2). When the gear 142 rotates in the first direction (rotation direction D1), the first shaft gear 141 rotates in the second direction (rotation direction D2). The first shaft gear 141 rotates in the second direction (rotation direction D2), so that the roll paper RP also rotates in the second direction (rotation direction D2) together with the support shaft 41, thereby winding up the medium.

[0050] If described differently, the power transmission mechanism 110 of this embodiment includes: a sun gear 131 that rotates under the driving force of the drive unit 120 and transmits the driving force of the drive unit 120 to the first roller gear 153; a planetary gear 132 that, when meshed with the sun gear 131, can move in a circle around the rotation center of the sun gear 131; and a rotating member 133 that, while holding the planetary gear 132, can rotate around the rotation center of the sun gear 131. Furthermore, the rotating member 133 is positioned such that, when the drive unit 120 rotates the drive roller 51a in the second direction (rotation direction D2), it is positioned such that the planetary gear 132 transmits the driving force of the drive unit 120 to the first shaft gear 141. Figures 2 to 4 The rotation is performed in the first position as shown. On the other hand, when the drive unit 120 rotates the drive roller 51a in the first direction (rotation direction D1), the rotating member 133 is positioned such that the planetary gear 132 does not transmit the driving force of the drive unit 120 to the first shaft gear 141. Figure 5 The rotation is performed in the second position shown.

[0051] When the front end PA of the medium is located downstream of the first roller pair 51 in the conveying direction A (positive direction), and a user-implemented disassembly operation is performed to remove the roll paper RP, which is the roll body, from the first medium holding section 42, the control unit 80 controls the drive unit 120 to perform the following operations. First, a first reverse conveying operation is performed, that is, the drive roller 51a is rotated in the second direction (rotation direction D2) by moving the medium in the opposite direction to the conveying direction A by an amount corresponding to a first distance as the desired distance. Next, a first forward conveying operation is performed, that is, the planetary gear 132 is moved from the first roller pair 51 to the second direction (rotation direction D2). Figures 2 to 4 The first position shown is towards Figure 5 The second position movement shown is used to rotate the drive roller 51a in the first direction (rotation direction D1). Then, a second reverse conveying operation is performed, that is, the drive roller 51a is rotated in the second direction (rotation direction D2) in such a way that the medium is moved in the opposite direction by an amount corresponding to a second distance as the desired distance.

[0052] By performing such an action, thus, for example, like by Figure 6 As shown by the dotted line, it is possible to prevent the first roller pair 51 from winding up the front end PA (front end PA1) of the medium, thus preventing the user from removing the roll of paper RP and other rolls. That is, by performing such an action, when removing the roll of medium, for example, as by... Figure 6 As shown by the solid line, the leading edge PA (leading edge PA2) of the medium can be positioned upstream in the conveying direction A (positive direction) compared to the first roller pair 51. Therefore, the printing apparatus 1 of this embodiment facilitates the removal of the roll of medium.

[0053] Furthermore, in the printing apparatus 1 of this embodiment, the first forward conveying action corresponds to the movement of the planetary gear 132 from the first position to the second position (the release action of the planetary gear 132), but in the second reverse conveying action, the planetary gear 132 is set to a movement amount that does not reach the first position (the planetary gear 132 remains in the released state). If other expressions are used, the amount of movement of the medium in the reverse direction generated by the second reverse conveying action will not become larger than the amount of movement of the medium in the forward direction generated by the first forward conveying action.

[0054] In addition, such as Figure 6As shown, the printing apparatus 1 of this embodiment includes a detection unit 81 capable of detecting the presence or absence of a medium. Specifically, the detection unit 81 includes detection units 81A and 81B, both with the same structure. Both detection units 81A and 81B can detect whether the position of the leading edge PA of the medium changes from being at the detection position of detection units 81A and 81B to not being at that position, or whether the position of the leading edge PA of the medium changes from not being at the detection position of detection units 81A and 81B to being at that position. Furthermore, with this structure, it is possible to detect whether the medium is located at a predetermined position in the transport path 30.

[0055] Both detection units 81A and 81B are positioned upstream of the first roller pair 51 in the conveying direction A (positive direction) along the conveying path 30. However, this configuration is not limited to this structure; it may also include only one of detection units 81A and 81B, or it may further include another detection unit 81. Here, after the first reverse conveying operation is completed, if the detection unit 81 detects that the medium is at a predetermined position, the control unit 80 executes the second reverse conveying operation.

[0056] By performing such an operation, the second reverse conveying operation can be performed only when the detection unit 81 detects the medium. That is, the second reverse conveying operation can be omitted when it is not necessary. Therefore, since the printing apparatus 1 of this embodiment can perform the second reverse conveying operation only when needed, the time for removing the roll of medium can be shortened and power can be saved. In addition, in the printing apparatus 1 of this embodiment, the detection unit 81 uses an optical method to detect the leading edge PA of the medium at a detection position upstream of the first roller pair 51 in the transport path 30 in the forward direction, thereby detecting whether the medium is located at a predetermined position in the transport path 30. However, as long as the detection unit 81 can detect whether the medium is located at a predetermined position in the transport path 30, it can also adopt a structure different from the detection unit 81 of this embodiment.

[0057] Furthermore, in the printing apparatus 1 of this embodiment, the control unit 80 releases the contact state of the second roller pair 52 after the second reverse conveying operation is completed. Specifically, it causes the driven roller 52b of the second roller pair 52 to move from... Figure 6 The position shown by the solid line is towards Figure 6The position is moved as indicated by the dotted line. By performing this action, when the front end PA of the medium is inserted into the conveying path 30 along with the installation of the next roll, the front end PA of the medium will not be hooked on the second roll pair 52, which is upstream in the positive direction compared to the first roll pair 51, thereby enabling good operability when installing the roll.

[0058] Furthermore, in the printing apparatus 1 of this embodiment, the detection unit 81, under the control of the control unit 80, performs a detection operation to determine whether the medium is in a predetermined position after the first forward conveying operation is completed. By performing such an operation, the second reverse conveying operation can be performed only when needed. That is, when the second reverse conveying operation is not required, it can be omitted. Therefore, it is possible to shorten the time for removing the roll of medium and save power.

[0059] Here, refer to Figure 7 The process of disassembling the roll body in the printing apparatus 1 of this embodiment will be described. When disassembling the roll body, firstly, a first reverse conveying operation is performed in step S110. Next, a first forward conveying operation is performed in step S120. Next, in step S130, a detection operation performed by the detection unit 81 is performed to detect whether the medium is at a predetermined position. If the medium is detected to be at the predetermined position in step S130, i.e., the leading edge PA of the medium has not yet been detected, it is assumed that there is a possibility that the medium is clamped by the first roller pair 51, and the process proceeds to step S140 to perform a second reverse conveying operation. By performing the second reverse conveying operation in step S140, the process ends. On the other hand, if the medium is not detected to be at the predetermined position in step S130, i.e., the leading edge PA of the medium is detected, it is assumed that there is no possibility that the medium is clamped by the first roller pair 51, and the process does not proceed to step S140; that is, the second reverse conveying operation is not performed, and the process ends.

[0060] This invention is not limited to the embodiments described above, but can be implemented through various structures without departing from its spirit. Furthermore, in order to solve some or all of the above-described problems, or to achieve some or all of the above-described effects, the technical features in the embodiments corresponding to the technical features in the various methods described in the summary section can be appropriately replaced or combined. Moreover, any technical feature that is not described as an essential technical feature in this specification can be appropriately deleted.

[0061] Symbol Explanation 1…Printing apparatus; 2…House; 14…Discharge port; 20…Printing section; 21…Carriage; 22…Head; 25…Support; 27…Cutting section; 30…Conveying path; 30a…Feeding path; 30b…Tilting path; 30c…Discharge path; 30R…Roll paper feeding path; 30S…Sheet paper feeding path; 31…Conveying section; 32…Intermediate roller; 33…Driven roller; 34…Upstream conveyor roller pair; 35…Downstream conveyor roller pair; 36…Roll pair; 37…Roll pair; 40…Roll paper storage section; 41…Support shaft ( 42…First media holding section; 43…Support member; 50…Roll paper conveying path; 51…First roller pair; 51a…Drive roller (first drive roller); 51b…Driven roller (first driven roller); 52…Second roller pair; 52a…Drive roller (second drive roller); 52b…Driven roller (second driven roller); 53…Third roller pair; 53a…Drive roller; 53b…Driven roller; 54…Curved surface; 54a…Curved surface; 60…Sheet paper receiving section; 61…Tray; 63…Placement surface; 64…Stop; 6 5…Edge guide; 70…Sheet feed unit; 71…Sheet transport path; 72…Pick-up roller; 73…Restriction roller; 74…Separation roller; 75…Sheet transport roller pair; 76…Separation component; 80…Control unit; 81…Detection unit; 81A…Detection unit; 81B…Detection unit; P1…Branch point; 100…Power transmission unit; 110…Power transmission mechanism; 120…Drive unit; 121…Gear; 122…Gear; 131…Sun gear; 132…Planet gear; 133…Rotating component; 14 0…First power transmission mechanism; 141…First shaft gear; 142…Gear; 143…Gear; 144…Gear; 145…Gear; 146…Gear; 150…Second power transmission mechanism; 151…Gear; 152…Gear; 153…First roller gear; 154…Gear; 155…Gear; 510…Second shaft; 520…Shaft; P2…Roll paper confluence point; P3…Sheet paper confluence point; PA…Front end; PA1…Front end; PA2…Front end; RP…Roll paper (roll body); SP…Sheet paper.

Claims

1. A printing apparatus, characterized in that, have: The medium holding part includes a first shaft that holds the elongated medium in a rotatable manner by winding it into a roll. A transport path that transports the medium; A printing section, which is opposite the medium being transported; The first roller pair has a first drive roller and a first driven roller, and rotates in a manner that enables the medium to be conveyed in the positive direction and in the opposite direction to the positive direction; A first shaft gear is mounted on the first shaft and causes the first shaft to rotate; A first roller gear is mounted on a second shaft that supports the first drive roller in a rotatable manner, and causes the first drive roller to rotate. The drive unit generates a driving force that causes the first drive roller to rotate in a first direction and in a second direction opposite to the first direction. A power transmission mechanism that, when the drive unit rotates the first drive roller in the second direction, transmits the driving force of the drive unit as a rotational force in the direction that causes the medium to rewind toward the medium holding part side to the first shaft; The control unit controls the drive unit. The power transmission mechanism includes a sun gear, planetary gears, and a rotating component. The sun gear rotates under the driving force of the drive unit and transmits the driving force to the first roller gear. When meshed with the sun gear, the planetary gears can move in circles around the rotation center of the sun gear. The rotating component, while holding the planetary gears, can rotate around the rotation center of the sun gear. The rotating component rotates such that, when the drive unit rotates the first drive roller in the second direction, it is positioned at a first position where the planetary gear transmits the driving force of the drive unit to the first shaft gear, and rotates such that, when the drive unit rotates the first drive roller in the first direction, it is positioned at a second position where the planetary gear does not transmit the driving force of the drive unit to the first shaft gear. The control unit controls the drive unit, and when the front end of the medium is located downstream of the first roller pair in the positive direction, a user-performed disassembly operation is performed on the drum body from the medium holding part. The first reverse conveying action is performed by rotating the first drive roller in the second direction in such a way that the medium is moved in the opposite direction by an amount corresponding to a first distance. The first forward conveying action is performed such that the first drive roller rotates in the first direction by moving the planetary gear from the first position to the second position. The second reverse conveying action is performed such that the first drive roller rotates in the second direction by moving the medium in the opposite direction by an amount corresponding to the second distance.

2. The printing apparatus as claimed in claim 1, characterized in that, The device includes a detection unit positioned upstream of the first roller pair in the conveying path in the forward direction, capable of detecting whether the medium is located at a predetermined position in the conveying path. When the control unit detects that the medium is located at the predetermined position after the first reverse conveying operation is completed, the detection unit executes the second reverse conveying operation.

3. The printing apparatus as described in claim 1 or 2, characterized in that, It includes a second roller pair, which has a second drive roller and a second driven roller, and rotates in a manner that conveys the medium in both the forward and reverse directions. The second roller pair is located upstream of the first roller pair in the positive direction, and is configured such that, in the event that the medium curls, the curled portion, which is the part where the curling occurs, can be bent in the direction that corrects the curled portion.

4. The printing apparatus as claimed in claim 3, characterized in that, After the second reverse conveying action is completed, the control unit releases the contact state of the second roller pair.

5. The printing apparatus as claimed in claim 2, characterized in that, The detection unit performs a detection action to determine whether the medium is located at the predetermined position after the first forward conveying action is completed.

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