Medium transport device and printer

Abstract

To provide a medium transport device which achieves downsizing easily, and to provide a printer.SOLUTION: A medium transport device 100 includes: a medium support part 101 which supports a transported medium M; a take-up part 109 which takes up the medium M; a tension bar 103 which applies tension to the medium M between the medium support part 101 and the take-up part 109; an arm part 105 which supports the tension bar 103 at one end; and a rotation part 107 which rotatably supports the other end of the arm part 105. The rotation part 107 is provided in the medium support part 101.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a medium conveyance device and a printing device.

Background Art

[0002] Conventionally, a medium conveyance device that winds a continuous sheet-like medium such as roll paper around a roll body has been known. Some such devices are provided with a tension bar to improve the winding accuracy of the medium. For example, Patent Document 1 discloses a printing device in which a tension bar is supported by a swing arm and a bracket.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, the device described in Patent Document 1 has a problem that it is difficult to miniaturize the device. Specifically, a swing arm that supports a tension bar is supported by a bracket, and the bracket is further attached to a leg portion. Therefore, the member that supports the swing arm may be relatively long. That is, there has been a demand for a medium conveyance device that is easy to miniaturize.

Means for Solving the Problems

[0005] The medium conveyance device includes a medium support portion that supports a medium to be conveyed, a winding portion that winds the medium, a tension bar that applies tension to the medium between the medium support portion and the winding portion, an arm portion that supports the tension bar at one end, and a rotating portion that rotatably supports the other end of the arm portion, and the rotating portion is provided on the medium support portion.

[0006] The printing apparatus includes a printing unit that performs printing on a medium, a medium support unit that supports the medium to be conveyed, a winding unit that winds up the medium, a tension bar that applies tension to the medium between the medium support unit and the winding unit, an arm unit that supports the tension bar at one end, and a rotation unit that rotatably supports the other end of the arm unit, and the rotation unit is provided on the medium support unit.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Modes for Carrying Out the Invention

[0008] In the embodiments described below, the medium conveyance apparatus 100 and the printing apparatus 1 including the medium conveyance apparatus 100 will be exemplified and described with reference to the drawings. The printing apparatus 1 is a large-format printer that performs printing on a continuous sheet-like form. Note that the medium conveyance apparatus of the present invention is not limited to being provided in a printing apparatus, and the printing apparatus of the present invention is not limited to the following configuration.

[0009] In the following figures, the XYZ axes are attached as coordinate axes orthogonal to each other, the direction indicated by each arrow is the + direction, and the direction opposite to the + direction is the - direction. When the printing apparatus 1 is installed on a horizontal plane, the -Z direction is the vertical direction. In the following description, the +Z direction is upward and the -Z direction is downward. Note that in the following figures, for the sake of illustration, the sizes of the respective members are made different from the actual ones.

[0010] As shown in FIG. 1, the printing apparatus 1 according to the present embodiment includes a structural member 10, a feeding unit 20, medium support members 30 and 50, a conveying unit 40, a printing unit 60, a blowing unit 80, a medium conveying device 100, and a housing (not shown). The printing apparatus 1 also includes a control unit (not shown). The control unit integrally controls the operation of each component of the printing apparatus 1 including the medium conveying device 100.

[0011] In FIG. 1, for the sake of illustration, the housing that houses the printing unit 60 and the like is omitted. In the description of FIG. 1 given below, unless otherwise specified, the state as viewed from the -X direction will be described.

[0012] The printing apparatus 1 produces printed matter by attaching ink to a medium M which is a continuous form sheet. In the printing apparatus 1, the medium M is fed from a roll body R1 which is a web, becomes printed matter, and the printed matter is wound up to become a roll body R2.

[0013] The control unit includes hardware such as a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory). The control unit controls the printing apparatus 1 by causing the CPU to execute a predetermined control program. The ROM is a non-volatile storage device that stores the control program executed by the CPU and the data processed by the control program. The RAM constitutes the work area of the CPU. The CPU expands the control program read from the ROM or the like into the RAM, and executes the expanded control program to control the printing apparatus 1.

[0014] The moving path of the medium M from the roll body R1 to the point where it is wound up as the roll body R2 is defined as the conveyance path. In FIG. 1, the conveyance path is indicated by a dashed line. In the conveyance path, the side of the medium M where the web is located is also referred to as the upstream side, and the side where the medium M and the printed matter advance is also referred to as the downstream side. In the conveyance path, in the order from upstream to downstream, a pay-out unit 20, a medium support member 30, a conveyance unit 40, a medium support member 50, a printing unit 60, a medium conveyance device 100, and a blower unit 80 are arranged in the above order. Note that in the conveyance path, the direction in which the medium M moves from upstream to downstream is also referred to as the conveyance direction.

[0015] The structural member 10 is a frame that supports each of the above components of the printing apparatus 1. The structural member 10 is formed by assembling a plurality of sheet metal members, tubular members, and the like. In the structural member 10, casters, installation members, or the like may be arranged at the portion that contacts the lower floor.

[0016] The pay-out unit 20 includes a roll body holding unit 21. The pay-out unit 20 is arranged in the -Y direction below the printing apparatus 1. The roll body holding unit 21 rotatably supports the roll body R1 about an axis along the X axis. The medium M is pulled by the conveyance unit 40, paid out from the roll body R1 downstream, and supplied. The roll body R1 is detachable from the printing apparatus 1. The medium M is conveyed by the conveyance unit 40 substantially upward from the roll body holding unit 21 and advances to the medium support member 30.

[0017] The medium M is appropriately selected according to the type of ink to be attached to the medium M, the use of the printed matter, and the like. In the printing apparatus 1, since so-called soft solvent ink is used as the ink, a sheet made of polyvinyl chloride or the like is applied as the medium M.

[0018] The medium support member 30 has a substantially arc-shaped curved surface and supports the conveyed medium M. The conveyance direction of the medium M is changed from substantially upward to substantially the +Y direction by the above curved surface of the medium support member 30. The medium M is conveyed while sliding in contact with the above curved surface of the medium support member 30. The medium M advances from the medium support member 30 to the conveyance unit 40.

[0019] Although illustration is omitted, the medium support member 30 incorporates an electric heater for heating the medium M. The electric heater pre-heats the medium M before the ink is attached. Thereby, the fixability and solubility of the ink with respect to the medium M are improved.

[0020] The conveyance unit 40 includes conveyance rollers 41 and 42. The conveyance rollers 41 and 42 are paired and their sides are in contact with each other. The conveyance roller 41 is disposed below the conveyance path, and the conveyance roller 42 is disposed above the conveyance path. The conveyance rollers 41 and 42 each rotate about an axis along the X-axis.

[0021] The conveyance roller 41 is driven by a drive motor (not shown) to rotate. The conveyance roller 42 is a driven roller and rotates in a direction opposite to that of the conveyance roller 41 due to the rotation of the conveyance roller 41. When the conveyance roller 41 rotates counterclockwise, the conveyance roller 42 rotates clockwise. Thereby, the medium M is sandwiched between the conveyance rollers 41 and 42 and conveyed downstream. Then the medium M proceeds to the medium support member 50.

[0022] The medium support member 50 is a member that constitutes a so-called platen. The upper surface of the medium support member 50 supports the medium M along the XY plane. In the medium support member 50, the conveyance direction of the medium M is the +Y direction. The surface facing upward of the medium M becomes the printing surface.

[0023] Although illustration is omitted, the medium support member 50 incorporates an electric heater for heating the medium M. The electric heater heats the medium M when the ink is attached. Thereby, the fixability and solubility of the ink with respect to the medium M are improved, and the volatile components such as the solvent contained in the ink are more likely to volatilize.

[0024] The printing unit 60 performs printing on the medium M. The printing unit 60 includes a head 61 and a carriage 62. The printing unit 60 is disposed above the medium support member 50. The carriage 62 is supported above the structural member 10 so as to be reciprocally movable along the X-axis. The above-mentioned reciprocating movement is driven by a carriage motor (not shown). The carriage 62 supports the head 61 above the medium support member 50.

[0025] The head 61 adheres ink to the printing surface of the medium M supported on the upper surface of the medium support member 50. The head 61, together with the carriage 62, reciprocates along the X-axis in a range including a region vertically opposed to the medium support member 50.

[0026] Although not shown, a nozzle surface is disposed on the surface facing downward of the head 61. A plurality of nozzle rows are provided on the nozzle surface. Each nozzle row consists of a plurality of nozzles that eject ink. For each nozzle row, inks presenting various colors such as black, cyan, yellow, and magenta, for example, are individually supplied from an ink storage container (not shown). The inks of various colors are ejected from each nozzle row toward the printing surface of the medium M.

[0027] The ink applied to the printing apparatus 1 is the soft solvent ink as described above. The soft solvent ink is, for example, a solvent ink that does not contain intentionally added water and contains a glycol ether-based solvent or a lactone-based solvent, etc. as a main solvent. Note that the ink ejected from the head 61 may include a treatment liquid and a clear ink that does not contain a coloring material.

[0028] While conveying the medium M in the +Y direction in the medium support member 50, the head 61 is reciprocally moved along the X-axis together with the carriage 62. At this time, by adhering ink to the printing surface of the medium M at an arbitrary timing, an image such as a picture, a photograph, text, a pattern, etc. is printed on the medium M. The printed medium M is pulled by the medium conveyance device 100 and proceeds to the downstream medium conveyance device 100 and the air blowing unit 80.

[0029] The media conveyance device 100 includes a media support portion 101, a heating portion 102, a tension bar 103, an arm portion 105, a rotating portion 107, and a winding portion 109.

[0030] Each component of the media conveyance device 100 is supported by the structural member 10 and is arranged in the +Y direction of the printing device 1. In the media conveyance device 100, the media support portion 101, the tension bar 103, and the winding portion 109 are arranged in the above order in the conveyance direction.

[0031] The media support portion 101 has a curved surface that is a surface for supporting the media M, and supports the conveyed media M. The above-mentioned curved surface of the media support portion 101 faces substantially upward in the media support portion 101. The media M is conveyed while sliding in contact with the above-mentioned curved surface of the media support portion 101. In the direction along the X axis, the length of the above-mentioned curved surface of the media support portion 101 is longer than the length of the media M. The conveyance direction of the media M is changed from the +Y direction to the +Y direction and slightly downward by the above-mentioned curved surface of the media support portion 101.

[0032] The media support portion 101 has a pair of side walls 101p. The side walls 101p are respectively arranged at the +X direction end and the -X direction end of the media support portion 101. Each side wall 101p is a substantially plate-shaped member and is formed by, for example, sheet metal. Each side wall 101p includes a surface that intersects the above-mentioned curved surface of the media support portion 101 along the YZ plane.

[0033] The media support portion 101 has a heating portion 102. The heating portion 102 is an electric heater that heats the media M. The heating portion 102 is arranged inside the above-mentioned curved surface of the media support portion 101. The heating portion 102 promotes the volatilization of the volatile components contained in the ink attached to the media M. Thereby, when the media M is wound around the roll body R2 by the winding portion 109, the adhesion of the ink components to other places can be prevented.

[0034] The air blowing portion 80 blows air onto the printing surface of the media M to assist the volatilization of the above-mentioned volatile components. The air blowing portion 80 is supported by the structural member 10 above the conveyance path of the media support portion 101. The air blowing portion 80 blows air over the entire range of the media M along the X axis.

[0035] Heating by the heating unit 102 and blowing by the blowing unit 80 promote drying of the ink adhered to the medium M. Therefore, the medium M can be wound up by the downstream winding unit 109. The medium M is pulled by the winding unit 109 and conveyed, and advances to the tension bar 103.

[0036] The tension bar 103 applies tension to the medium M between the medium support unit 101 and the winding unit 109. The tension bar 103 is a substantially cylindrical member, and the length direction of the cylinder is arranged along the X axis. The -X direction end and the +X direction end of the tension bar 103 are each supported by the arm part 105. The tension bar 103 is supported by the pair of arm parts 105 and protrudes slightly downward in the +Y direction from the medium support unit 101.

[0037] In a configuration without the tension bar 103, the medium M advances from the +Y direction end of the medium support unit 101 to the substantially lower winding unit 109. On the other hand, in the printing apparatus 1, since the tension bar 103 protrudes downward and slightly in the +Y direction from the medium support unit 101, the medium M is conveyed while being pushed substantially in the +Y direction by the tension bar 103. Thereby, the medium M is wound up by the winding unit 109 while tension is applied.

[0038] The surface corresponding to the side surface of the cylinder of the tension bar 103 is formed relatively smoothly with low frictional resistance. Therefore, the medium M slides on the side surface of the tension bar 103 while tension is applied. The side surface of the cylinder of the tension bar 103 may be covered with a sheet-like member that contacts the medium M. Note that the tension bar 103 does not rotate with respect to the arm part 105.

[0039] Each arm part 105 is a substantially rod-shaped member. In a state where the tension bar 103 functions, each arm part 105 supports the tension bar 103 at one end in the substantially +Y direction. The other end in the substantially -Y direction of each arm part 105 is rotatably supported by the rotating part 107.

[0040] In a plan view from above, the length, which is the distance between one end and the other end of each arm portion 105, is shorter than the length along the conveyance direction of the medium support portion 101. As a result, since the arm portion 105 and the like are relatively small, the medium conveyance device 100 can be further miniaturized.

[0041] The rotation portions 107 are arranged corresponding to the respective arm portions 105. Specifically, the rotation portions 107 are provided on the side wall 101p in the +X direction and the side wall 101p in the -X direction in the medium support portion 101. The pair of rotation portions 107 rotate clockwise and counterclockwise with the vicinity of the other end of each arm portion 105 as the rotation center by the drive of a drive portion described later.

[0042] Therefore, one end of each arm portion 105 rotates clockwise and counterclockwise while supporting the tension bar 103. As a result, the position of the tension bar 103, particularly the protruding distance in the +Y direction, changes, and the strength of the tension applied to the medium M is adjusted. Specifically, when the tension bar 103 rotates clockwise, the protruding distance of the tension bar 103 in the +Y direction from the medium support portion 101 becomes longer, and the medium M is pushed in the +Y direction and a strong tension is applied. Also, when the tension bar 103 rotates counterclockwise, the protruding distance of the tension bar 103 in the +Y direction from the medium support portion 101 becomes shorter, the force with which the medium M is pushed in the +Y direction weakens, and the applied tension is reduced.

[0043] Each rotation portion 107 is provided at a position closer to the end in the +Y direction, which is the downstream end, than the end in the -Y direction, which is the upstream end of the medium support portion 101, with respect to the conveyance direction of the medium M. Thereby, compared with the case where each rotation portion 107 is provided closer to the upstream end of the medium support portion 101, the length of the arm portion 105 is shortened. Therefore, the miniaturization of the medium conveyance device 100 becomes easier, and the weight and cost of the device are further reduced.

[0044] By the tension bar 103, the conveyance direction of the medium M is changed from the downward direction in the +Y direction to the downward direction in the -Y direction. The medium M advances to the winding portion 109 via the tension bar 103.

[0045] The winding unit 109 winds the medium M onto the roll body R2. The winding unit 109 includes a roll body holding part 109a. The winding unit 109 is arranged in the +Y direction below the printing device 1. The roll body holding part 109a rotates counterclockwise by the rotational drive of a drive motor (not shown) to wind the medium M as the roll body R2. At this time, the roll body R2 rotates about an axis along the X-axis.

[0046] When winding the medium M onto the roll body R2, the tension applied by the tension bar 103 improves the winding accuracy. Therefore, the positional deviation at both ends of the medium M along the X-axis is reduced, and the roll body R2 with relatively aligned both ends is obtained. Also, the gap between the media M stacked due to the applied tension is reduced, and a dense roll body R2 is obtained. There is an appropriate range for the strength of the tension applied to the medium M. The above tension is appropriately set according to the type and dimensions of the medium M, etc.

[0047] As described above, the medium M which is a printed matter becomes the roll body R2. The roll body R2 can be removed from the printing device 1 in the substantially +Y direction.

[0048] As shown in FIG. 2, side walls 101p are respectively arranged at the -X direction end portion and the +X direction end portion of the medium support part 101. A rotating part 107 and an arm part 105 are arranged on each side wall 101p. Both ends of the tension bar 103 in the direction along the X-axis are supported by the arm part 105. In FIG. 2, illustration of the housing of the printing device 1 and other configurations including the printing part 60 is omitted.

[0049] As shown in FIG. 3, a drive part 106 is attached to the rotating part 107. Although illustration is omitted, the rotating part 107 includes gears, and the drive part 106 includes gears and a spring member. In the following description of FIG. 3, unless otherwise specified, the state as viewed from the -X direction is described.

[0050] The gear of the rotating part 107 and the gear of the driving part 106 are supported by the side wall 101p so as to be rotatable about the central axis along the X-axis. The gear of the rotating part 107 and the gear of the driving part 106 are engaged with each other.

[0051] The gear of the driving part 106 is biased by the spring member of the driving part 106 to rotate counterclockwise in a state where the tension bar 103 functions. The biasing force of the spring member is transmitted to the rotating part 107, and the rotating part 107 is biased to rotate clockwise. As a result, one end of the arm part 105 in the substantially +Y direction is lifted upward, and tension is applied to a medium M (not shown) by the tension bar 103.

[0052] The strength of the tension applied to the medium M is adjusted by the elastic coefficient of the spring member of the driving part 106, the gear ratio between the gear of the driving part 106 and the gear of the rotating part 107, the length and mass of the arm part 105, etc. Also, as the driving part 106, a motor or the like may be applied. In this case, the arm part 105 is rotated by the rotational driving force of the motor.

[0053] The tension bar 103 and the arm part 105 can be stored under the medium support part 101, for example, in a scene where a roll body R2 (not shown) is removed from the printing apparatus 1. Specifically, the user of the printing apparatus 1 manually rotates the tension bar 103 and the arm part 105 counterclockwise against the biasing force of the spring member. The arm part 105 abuts against the stopper 108 and does not rotate any further. When it abuts against the stopper 108, the arm part 105 is fixed in that state. At this time, the arm part 105 is fixed by, for example, a magnet or the like.

[0054] When using the printing apparatus 1, the tension bar 103 and the arm part 105 are manually rotated clockwise to return them.

[0055] Since the tension bar 103 is folded together with the arm portion 105, the area occupied when the printing apparatus 1 is not in use is reduced. In addition to the folding operation being simple, it does not interfere with the removal of the roll body R2, improving workability.

[0056] Note that components such as the drive unit 106 and the stopper 108 are installed on each of the side wall 101p in the +X direction and the side wall 101p in the -X direction, similar to the rotating unit 107 and the arm portion 105.

[0057] Here, with reference to FIGS. 4 and 5, the printing apparatus 1 and the medium conveyance apparatus 100 of the embodiment and the printing apparatus 2 and the medium conveyance apparatus 200 of the comparative example will be described while comparing the two.

[0058] As shown in FIG. 5, the printing apparatus 2 of the comparative example includes the medium conveyance apparatus 200 of the comparative example. The printing apparatus 2 has the same configuration as the printing apparatus 1 of the embodiment, except that the medium conveyance apparatus 100 is replaced with the medium conveyance apparatus 200. Further, the medium conveyance apparatus 200 of the comparative example has the same configuration as the medium conveyance apparatus 100 of the embodiment, except that the arrangement and form of the arm portion 105 are changed. Therefore, in the following description of the printing apparatus 2 and the medium conveyance apparatus 200, the same reference numerals are applied to the configurations common to the above embodiment, and redundant descriptions are omitted. In the following description of FIGS. 4 and 5, unless otherwise specified, the state as viewed from the +X direction is described.

[0059] As shown in FIGS. 4 and 5, the arm portion 105 of the medium conveyance apparatus 100 is supported by the medium support portion 101 via the rotating portion 107, and the arm portion 205 of the medium conveyance apparatus 200 is supported by the structural member 10 via the rotating portion 207. Therefore, the distance to the tension bar 103, that is, the length of the arm portion 205, is longer than that of the arm portion 105. Also, the weight of the arm portion 205 is heavier than the weight of the arm portion 105.

[0060] Therefore, in the medium conveyance device 200, in order to rotate the arm portion 205, it is necessary to increase the biasing force and driving force compared to the medium conveyance device 100. Specifically, for example, a weight 207a is attached to the rotating portion 207 to relieve the weight of the arm portion 205 and ensure balance with the heavy arm portion 205. As a result, it becomes difficult to miniaturize the medium conveyance device 200 and the printing device 2, and the device weight and cost are also likely to increase.

[0061] In addition, the long arm portion 205 is likely to interfere with the roll body R2, and the workability is likely to deteriorate when removing the roll body R2 or the like.

[0062] On the other hand, in the medium conveyance device 100, the arm portion 105 is relatively short, and the biasing force and driving force required for rotation may be small. Further, in the medium conveyance device 100, as described above, it is also possible to retract the arm portion 105 and the tension bar 103 below the medium support portion 101.

[0063] According to the present embodiment, the following effects can be obtained.

[0064] The device can be easily miniaturized. Specifically, since the rotating portion 107 is supported by the medium support portion 101, relatively long brackets, long arm portions, etc. are not required. Therefore, it is possible to provide the medium conveyance device 100 and the printing device 1 that are easy to miniaturize. In addition, an increase in the number of parts can be suppressed, and the device weight and cost can be reduced.

Explanation of Reference Numerals

[0065] 1... printing device, 60... printing unit, 100... medium conveyance device, 101... medium support portion, 101p... side wall, 102... heating portion, 103... tension bar, 105... arm portion, 107... rotating portion, 109... winding portion, M... medium.

Claims

1. a medium support portion that supports the medium to be conveyed; a winding portion that winds up the medium; a tension bar that applies tension to the medium between the medium support portion and the winding portion; an arm portion that supports the tension bar at one end; a rotating portion that rotatably supports the other end of the arm portion, and the rotating portion is provided on the medium support portion. A medium conveyance device characterized by this.

2. The medium conveyance device according to claim 1, wherein the rotating portion is provided at a position closer to the downstream end than the upstream end of the medium support portion with respect to the conveyance direction of the medium.

3. The medium conveyance device according to claim 2, wherein the length of the arm portion is shorter than the length of the medium support portion in the conveyance direction in a plan view.

4. The medium conveyance device according to claim 1, wherein the arm portion can be stored below the medium support portion by rotating the rotating portion.

5. The medium support portion has a side wall including a surface intersecting the surface that supports the medium, and the rotating portion is provided on the side wall. The medium conveyance device according to claim 1.

6. The medium conveyance device according to claim 1, wherein the medium support portion has a heating portion that heats the medium.

7. a printing portion that performs printing on the medium; a medium support portion that supports the medium to be conveyed; a winding portion that winds up the medium; a tension bar that applies tension to the medium between the medium support portion and the winding portion; an arm portion that supports the tension bar at one end; a rotating portion that rotatably supports the other end of the arm portion, and the rotating portion is provided on the medium support portion. A printing device characterized by this.

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