Sheet conveying apparatus and recording apparatus

Abstract

To provide a sheet conveying device capable of suppressing instability of sheet conveyance.SOLUTION: A holding unit configured to hold a roll sheet around which a sheet is wound, a first driving unit configured to rotate the roll sheet held by the holding unit in a first direction and a second direction opposite to the first direction, a pair of rollers configured to nip a continuous sheet from the roll sheet held by the holding unit, a second driving unit configured to rotationally drive the pair of rollers, and a moving unit configured to be linearly movable in a moving direction intersecting the conveyance direction between the holding unit and the pair of rollers in the conveyance direction of the sheet; The image forming apparatus includes a dancer roller abutting on a sheet, a position detection part detecting a position in a moving direction of the dancer roller, and a control part executing first control for adjusting a position of the dancer roller by a first driving means before starting conveyance of the sheet by a second driving means based on a detection result of the position detection part and second control for starting conveyance of the sheet by the second driving means without executing the first control.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a sheet transport device and a recording apparatus equipped with the sheet transport device. [Background technology]

[0002] 2. Description of the Related Art A known sheet conveying device holds a rolled sheet, pulls out the sheet from the rolled sheet, and conveys the sheet. The device has a dancer roller that movably contacts the sheet and absorbs slack in the sheet.

[0003] Patent document 1 discloses a configuration in a recording device (printing device) equipped with a dancer roller in which, in certain cases, sheet transport is started at a speed slower than a target speed in order to prevent the dancer roller from bottoming out. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2022-083640 Summary of the Invention [Problem to be solved by the invention]

[0005] However, if the conveying speed is set low at the start of conveying, as in the above configuration, it takes time to reach the target conveying speed. Also, if the conveying speed is not sufficiently reduced, there is a risk that the occurrence of downward contact of the dancer roller cannot be suppressed.

[0006] In view of the above-mentioned problems, an object of the present invention is to provide a sheet conveying device that suppresses instability in sheet conveyance. [Means for solving the problem]

[0007] In order to achieve the above object, a sheet conveying device of the present invention comprises: a holding section that holds a roll sheet on which a sheet is wound; a first driving means for rotating the roll sheet held by the holding portion in a first direction and a second direction opposite to the first direction; a pair of rollers that sandwich a continuous sheet from the roll sheet held by the holding unit; a second driving means for driving the pair of rollers to rotate; a dancer roller configured to be linearly movable in a movement direction intersecting the sheet conveyance direction between the holding portion and the roller pair in the sheet conveyance direction and to come into contact with the sheet; a position detection unit that detects the position of the dancer roller in the movement direction; a control unit that executes a first control to adjust the position of the dancer roller by the first driving means before starting conveyance of the sheet by the second driving means based on a detection result of the position detection unit, and a second control to start conveyance of the sheet by the second driving means without executing the first control; The present invention is characterized by comprising: [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a sheet conveying device that suppresses instability in sheet conveyance. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram showing a schematic configuration of a recording apparatus according to a first embodiment. [Figure 2] FIG. 2 is a block diagram showing the control configuration of the recording apparatus according to the first embodiment. [Figure 3] FIG. 3 is an explanatory diagram of a holding structure for a dancer roller according to the first embodiment. [Figure 4] FIG. 10 is a diagram showing a state in which the dancer roller is at an upper limit position. [Figure 5] FIG. 10 is a diagram showing a state in which the dancer roller is at a lower limit position. [Figure 6] 10 is a flowchart of a transfer start sequence according to the first embodiment. [Figure 7]FIG. 10 is a diagram showing a state in which the dancer roller is positioned at a target position. [Figure 8] FIG. 10 is a diagram illustrating a state in which a sheet is conveyed at a target speed. [Figure 9] FIG. 10 is a diagram showing a state in which the dancer roller is positioned at an upper limit position. [Figure 10] FIG. 10 is a diagram showing a state in which the dancer roller is located at a lower limit position. DETAILED DESCRIPTION OF THE INVENTION

[0010] The following describes in detail exemplary embodiments of the present invention with reference to the drawings. The dimensions, materials, shapes, and relative positions of the components described in the embodiments may be changed as appropriate depending on the configuration and various conditions of the device to which the invention is applied. In other words, the scope of the present invention is not limited to the following embodiments.

[0011] First Embodiment The following describes a recording device 90 according to a first embodiment of the present invention. The recording device 90 is a printing device that includes a sheet conveying unit (sheet conveying device) that rotatably holds a roll sheet on which a sheet is wound and conveys a continuous sheet from the roll sheet, and a recording unit that records an image on the sheet conveyed to the sheet conveying unit.

[0012] In this specification, "printing" (sometimes called "recording" or "printing") refers not only to the formation of meaningful information such as characters and figures, but also to the formation of images, designs, patterns, etc. on a recording medium or the processing of a medium, regardless of whether the information is visible to humans or not.

[0013] (Recording device 90) The schematic configuration of the recording device 90 will be described. Fig. 1 is a diagram showing the schematic configuration of the recording device 90. Fig. 1 shows the recording device 90 in a standby state, as viewed in the direction of the rotation axes of various rollers that transport the sheet 20a being pulled out from the roll sheet 20. In this embodiment, the transport direction Dc of the sheet 20a is a direction that intersects (is perpendicular to) the rotation axes of the various rollers, and the width direction of the sheet 20a is a direction parallel to the rotation axes of the various rollers.

[0014] Note that Fig. 1 is a simplified diagram showing only the main components. An actual recording device 90 can be configured, for example, so that an image is recorded on the sheet 20a as it is transported from right to left in Fig. 1, the sheet 20a is transported downward, dried and cooled as it is transported from left to right in Fig. 1, and then transported further downward and from right to left in Fig. 1. Thus, in Fig. 1, the transport path of the sheet 20a in the recording device 90 is depicted as being approximately linear from right to left, but the transport path of the sheet 20a may also be configured to form a large S-shape.

[0015] The recording device 90 is provided with a feeding section 10 (paper feeding section), a main conveying section 12, a recording section 13, a fixing section 14, a sub-conveying section 15, and a winding section 17 along the conveying path of the sheet 20a, in that order from upstream to downstream in the conveying direction Dc of the sheet 20a during recording operation.

[0016] The feeding unit 10 is a paper feeding device that rotatably holds a rolled sheet 20 around which a sheet 20a is wound. The feeding unit 10 includes a holding unit that holds the rolled sheet 20 and a drive unit that rotates the rolled sheet 20 held by the holding unit in a first direction D1 and a second direction D2 opposite to the first direction D1. The feeding unit 10 is configured to be rotatable by a driving source (drive means). The first direction D1 is a feeding direction (unwinding direction) in which the sheet 20a is sent out in the conveying direction Dc. The second direction D2 is a winding direction in which the sheet 20a is sent in the direction opposite to the conveying direction Dc so as to be wound up. In other words, the feeding unit 10 is configured to be rotatable by a driving source (not shown) so as to rotate the roll sheet 20 in the first direction D1 and the second direction D2.

[0017] The winding unit 17 is a winding device that rotatably holds the rolled sheet 20. The winding unit 17 includes a holding unit that holds the rolled sheet 20 and a drive source (driving means) that rotates the rolled sheet 20 held by the holding unit in a third direction D3 and a fourth direction D4 opposite to the third direction D3. The third direction D3 is the feeding direction (unwinding direction) in which the sheet 20a is fed in the direction opposite to the conveying direction Dc. The fourth direction D4 is the winding direction in which the sheet 20a is fed in the conveying direction Dc so as to be wound up. In other words, the winding unit 17 is rotatably configured to rotate the rolled sheet 20 in the third direction D3 and the fourth direction D4 by a drive source (not shown).

[0018] For convenience, the feeding unit 10 and the winding unit 17 are named according to the operation they perform during the recording operation on the sheet 20a. However, as described above, in the first embodiment, the feeding unit 10 can also perform the winding operation of the sheet 20a, and the winding unit 17 can also perform the feeding operation of the sheet 20a. In other words, the recording device 90 includes the feeding unit 10 (first holding unit) and the winding unit 17 (second holding unit) as holding units that hold the roll sheet so that it can rotate in both directions.

[0019] The main transport unit 12 has a roller pair 12a capable of sandwiching and transporting the sheet 20a, and the sub-transport unit 15 has a roller pair 15a capable of sandwiching and transporting the sheet 20a. The roller pairs 12a and 15a constituting the main transport unit 12 and the sub-transport unit 15 rotate, transporting the sheet 20a in the transport direction Dc so that the sheet passes through the recording unit 13 and the fixing unit 14. Thus, the recording device 90 includes a first roller pair provided in the main transport unit 12 and a second roller pair provided in the sub-transport unit 15. The roller pairs 12a and 15a are each driven to rotate by a drive unit (not shown). That is, the recording device 90 includes a first drive unit that drives and rotates the rolled sheet 20 in the feeding unit 10, a second drive unit that drives and rotates the roller pair 12a, a third drive unit that drives and rotates the rolled sheet 20 in the winding unit 17, and a fourth drive unit that drives and rotates the roller pair 15a. The first drive means and the third drive means are simply assigned different numbers for the sake of convenience, but are essentially the same in the sense that they are drive means for rotating the rolled sheet 20 they hold. The same applies to the relationship between the second drive means and the fourth drive means. All of these drive means (drive sources) are controlled by the control unit.

[0020] The recording unit 13 has a plurality of heads 13a as recording heads (liquid ejection heads) that eject liquid such as ink toward the sheet 20a to record an image on the sheet. While Fig. 1 illustrates a configuration in which four heads 13a are provided, the configuration of the recording unit 13 is not limited to this. In this embodiment, each head 13a corresponds to a different color of ink, and a recording operation is performed by each head 13a ejecting ink of a different color onto the sheet 20a.

[0021] The fixing unit 14 is disposed downstream of the recording unit 13 in the conveying direction Dc, and is provided to fix the image recorded on the sheet. The fixing unit 14 can be configured, for example, with a drying unit (heating unit) that dries the ink applied to the sheet, and a cooling unit that cools the sheet 20a that has been heated by the drying unit.

[0022] The recording device 90 includes a dancer roller 30 as a first dancer roller and a dancer roller 40 as a second dancer roller. The dancer roller 30 moves in a direction intersecting the conveying direction Dc between the feeding section 10 and the main conveying section 12 in the conveying direction Dc (in this example, The dancer rollers 30 and 40 are configured to be linearly movable in a movement direction (vertical direction in this example) that intersects with the conveying direction Dc between the winding section 17 and the sub-conveying section 15 in the conveying direction Dc, and are rollers that come into contact with the sheet. The dancer rollers 30 and 40 are rotatable slack absorption members that are provided to absorb slack in the sheet 20a, and are supported so that they can be raised and lowered according to the amount of slack in the sheet 20a.

[0023] A force is applied downward (in the direction in which tension is applied to the sheet 20a) to the dancer rollers 30 and 40 by a tensioning mechanism (not shown). The tensioning mechanism is, for example, an air cylinder. The recording device 90 also includes a roller position sensor 31 as a first position detector capable of detecting the position of the dancer roller 30 in the movable direction, and a roller position sensor 41 as a second position detector capable of detecting the position of the dancer roller 40 in the movable direction. By providing the roller position sensors 31 and 41, the positions of the roller position sensors 31 and 41 in the movable direction can be sensed.

[0024] A splice table 11 and a sheet nip unit 32 are provided downstream of the feed unit 10 in the conveying direction Dc and upstream of the dancer roller 30 in the conveying direction Dc. A user can fix the sheet 20a drawn from the roll sheet 20 attached to the feed unit 10 using the splice table 11 and the sheet nip unit 32. The user can then cut the sheet 20a on the splice table 11, replace the roll sheet 20 in the feed unit 10, and splice the rear end of the cut sheet 20a on the splice table 11 to the front end of the sheet 20a drawn from the new roll sheet 20 using splice tape. In this way, the recording device 90 is configured so that the roll sheet 20 can be replaced simply by replacing the roll sheet 20 with a new one in the feed unit 10 and passing the sheet 20a from the feed unit 10 to the position of the splice table 11.

[0025] A meandering correction unit 50 for correcting meandering of the sheet 20a is provided downstream in the conveying direction Dc of the main conveying unit 12 and upstream in the conveying direction Dc of the recording unit 13. The meandering correction unit 50 is a meandering correction device for correcting the position of the sheet 20a in the width direction during conveyance.

[0026] A sheet nip section 42 and a nip table 44 are provided upstream of the winding section 17 in the conveying direction Dc and downstream of the dancer roller 40 in the conveying direction Dc. The sheet 20a, which has been cooled in the fixing section 14 and passed through the sub-conveyance section 15, passes between the sheet nip section 42 and the nip table 44 before being wound into the winding section 17. When removing the roll sheet 20 around which the finished product is wound from the winding section 17, the sheet 20a is fixed by the sheet nip section 42 and the nip table 44, and the sheet 20a is cut between the fixing section and the winding section 17, so that the roll sheet 20 can be removed from the winding section 17. Thereafter, a cardboard tube is attached to the winding section 17, and the cut portion of the sheet 20a is affixed to the cardboard tube with splice tape, completing preparation for the next winding.

[0027] 2 is a block diagram showing the control configuration of the recording device 90. The control configuration is mainly composed of a print engine unit 200 that controls the print engine, and a controller unit 100 that controls the entire recording device 90. A print controller 202 controls various mechanisms of the print engine unit 200 according to instructions from a main controller 101 of the controller unit 100. The control configuration will be described in detail below.

[0028] In the controller unit 100, a main controller 101 made up of a CPU controls the entire printing apparatus using a RAM 105 as a work area in accordance with programs and various parameters stored in a ROM 106. For example, when a print job is input from a host device 300 via a host I / F 102, an image processing unit 107 performs predetermined image processing on the received image data in accordance with instructions from the main controller 101. The main controller 101 then executes the image processing via a print engine I / F 104. The processed image data is sent to the print engine unit 200.

[0029] The recording device 90 may acquire image data from a connected external storage device (such as a USB memory). The operation panel 103 is a mechanism that allows the user to input and output data to and from the recording device 90. The user can use the operation panel 103 to instruct printing and paper feed operations, set print modes, and view information about the recording device 90. The operation panel 103 is a touch panel, and it is also possible to connect a mouse and keyboard for input.

[0030] In the print engine unit 200, a print controller 202 configured by a CPU controls various mechanisms provided in the recording device 90 in accordance with programs and various parameters stored in a ROM 203, using a RAM 204 as a work area.

[0031] When various commands and image data are received via the controller I / F 201, the print controller 202 temporarily stores them in RAM 204. The print controller 202 causes the image processing controller 205 to convert the stored image data into print data so that the head 13a can use it for printing. Once the print data is generated, the print controller 202 causes the head 13a to execute printing based on the print data via the head I / F 206. At this time, the print controller 202 drives the feed unit 10, main transport unit 12, sub-transport unit 15, and winding unit 17 shown in FIG. 1 via the transport control unit 207 to transport the sheet 20a, which is a printing medium.

[0032] The transport control unit 207 is a control unit that can detect the transport amount from an encoder provided on the transport roller. The print controller 202 performs printing processing by executing a recording operation at a predetermined timing. The transport control unit 207 independently controls the operation of the drive means (drive source) that rotates the roll sheet in the feed unit 10 and the winding unit 17, and the drive means (motor) that rotates the roller pair 12a and the roller pair 15a.

[0033] In the recording unit 13, the head 13a is configured to be movable up and down. When performing a recording operation, the head 13a is in a lowered recording position as shown in Fig. 1, but can be moved from the recording position to a raised position during maintenance, etc. The head carriage control unit 208 changes the up and down position of the head 13a depending on the operating state of the recording device 90, such as the maintenance state or recording state.

[0034] The ink supply control unit 209 controls the ink supply unit so that the pressure of the ink supplied to the head 13a falls within an appropriate range. When performing maintenance operations on the head 13a, the maintenance control unit 210 moves the maintenance unit to below the raised head and controls maintenance operations for the head 13a, such as capping and wiping.

[0035] (Dancer Laura) Next, the holding structure of the dancer roller 30 will be described in detail. Figures 3(a) and (b) are explanatory diagrams of the holding structure of the dancer roller 30 according to the first embodiment. Figure 3(a) is a diagram of the dancer roller 30 and its holding structure as viewed in the direction of the rotation axis of the dancer roller 30. Figure 3(b) is a diagram of the dancer roller 30 and its holding structure as viewed in a direction perpendicular to the rotation axis of the dancer roller 30. In Figures 3(a) and (b), the outline of the sheet 20a whose slack is absorbed by the dancer roller 30 is shown by a dotted line.

[0036] The recording device 90 is equipped with a dancer roller holding unit 60 that rotatably holds the dancer roller 30. The dancer roller holding unit 60 is configured to be movable (up and down) in the vertical direction together with the dancer roller 30 relative to the device body (housing) of the recording device 90. The dancer roller holding section 60 has attached thereto sliding shafts 61 provided on both sides of the area through which the sheet 20a passes. The sliding shafts 61 are shafts that extend vertically (in the direction of gravity), and the dancer roller holding section 60 is composed of a shaft attachment section that is slidably attached to the sliding shafts 61, and a roller holding section that is connected to the shaft attachment section and rotatably holds the dancer roller 30.

[0037] The movable ranges of the dancer roller holding part 60 and the dancer roller 30 are defined by an upper limit abutment member 62 and a lower limit abutment member 63. The upper limit abutment member 62 is attached to the upper end of the sliding shaft 61, and the lower limit abutment member 63 is a defining member attached to the lower end of the sliding shaft 61. The position where the dancer roller holding part 60 abuts against the upper limit abutment member 62 is the upper limit of the movable range of the dancer roller 30, and the position where the dancer roller holding part 60 abuts against the lower limit abutment member 63 is the lower limit of the movable range of the dancer roller 30.

[0038] Figures 4(a) and (b) are views showing the dancer roller 30 at the upper limit position of its movable range. Figure 4(a) is a view of the dancer roller 30 and its holding structure viewed in the direction of the rotation axis of the dancer roller 30. Figure 4(b) is a view of the dancer roller 30 and its holding structure viewed in a direction perpendicular to the direction of the rotation axis of the dancer roller 30. At this time, part of the dancer roller holding part 60 is in contact with the upper limit abutment member 62.

[0039] Figures 5(a) and (b) are views showing the dancer roller 30 at the lower limit position of its movable range. Figure 5(a) is a view of the dancer roller 30 and its holding structure viewed in the direction of the rotation axis of the dancer roller 30. Figure 5(b) is a view of the dancer roller 30 and its holding structure viewed in a direction perpendicular to the rotation axis of the dancer roller 30. At this time, part of the dancer roller holding part 60 is in contact with the lower limit abutment member 63.

[0040] The recording device 90 further includes a roller position sensor 31 as a position detection unit capable of detecting the position of the dancer roller 30. The roller position sensor 31 according to the first embodiment is a laser distance sensor that uses a laser to measure the distance to a predetermined position on the dancer roller holding unit 60. It is possible to calculate the position of the movable range of the dancer roller 30 from the mounting position of the roller position sensor 31, the inclination between the laser optical axis and the sliding axis 61, and the measurement results.

[0041] The recording device 90 is equipped with an air cylinder 64 as a biasing unit that biases the dancer roller holding unit 60 downward. The air cylinder 64 biases the dancer roller 30 downward via the dancer roller holding unit 60 using air pressure. The biasing force of the air cylinder 64 applies tension to the sheet 20a wrapped around the dancer roller 30. With this configuration, the dancer roller 30 moves up and down within its movable range, thereby maintaining a constant tension in the sheet 20a and preventing sagging of the sheet 20a.

[0042] The holding structure of the dancer roller 40 is the same as that of the dancer roller 30, and therefore will not be described here. In the following explanation, the dancer roller 30 will be used as the basic structure, but the dancer roller 40 also has a similar structure and operates in the same way.

[0043] As described above, the dancer roller 30 has a limited range of movement. Therefore, when the dancer roller 30 is located near the upper or lower limit of its range of movement, it is desirable to adjust the position of the dancer roller 30 as appropriate. One possible method for controlling the position adjustment of the dancer roller 30 is feedback control such as PID control that uses position information of the dancer roller 30 acquired by the roller position sensor 31.

[0044] However, for example, if sheet conveyance is started in a state where the dancer roller 30 is positioned near the upper limit of its movable range, even if feedback control is performed, the dancer roller 30 may move too far, especially immediately after the start of sheet conveyance. There is a risk that the dancer roller 30 may attempt to move beyond its upper limit position. Furthermore, when the dancer roller 30 is positioned near the lower limit of its movable range, there is a risk that the dancer roller 30 may attempt to move beyond the lower limit position even if feedback control is performed using sheet transport. Hereinafter, the dancer roller 30 attempting to move beyond the upper limit of its movable range will be referred to as "upward sticking," and the dancer roller 30 attempting to move beyond the lower limit will be referred to as "downward sticking." Upward sticking or downward sticking of the dancer roller 30 can occur due to factors such as the difference in conveying speed between the main conveying unit 12 and the feeding unit 10.

[0045] The upward or downward contact of the dancer roller 30 may lead to instability in the conveyance of the sheet 20a or breakage of the sheet 20a due to excessive tension. Therefore, the recording device 90 according to the first embodiment is configured to be able to execute processing to prevent the upward or downward contact of the dancer roller 30 during the conveyance start sequence that starts conveyance of the sheet 20a.

[0046] (Transportation start sequence) The following describes the conveyance start sequence of the recording device 90. The conveyance start sequence is a sequence for conveying the sheet 20a, which is drawn out from the roll sheet 20, at a target speed. Hereinafter, with regard to the conveyance path of the sheet 20a, the section between the feeding section 10 and the main conveyance section 12 in the conveyance direction Dc will be referred to as the feeding section (paper feeding section), the section between the main conveyance section 12 and the sub-conveyance section 15 as the main conveyance section, and the section between the sub-conveyance section 15 and the winding section 17 as the winding section (paper discharge section).

[0047] Fig. 6 is a flowchart of the conveyance start sequence according to the first embodiment. Figs. 7 to 10 are explanatory diagrams of the conveyance start sequence, showing the configuration of the feeding section. In the first embodiment, the conveyance start sequence includes a first control for adjusting the position of the dancer roller 30 before starting conveyance of the sheet 20a in the main conveyance section, and a second control for starting conveyance of the sheet 20a in the main conveyance section.

[0048] When the conveyance start sequence is started, first, in step (hereinafter referred to as S) 010, the conveyance control unit 207 nips the sheet 20a in the main conveyance unit 12 and the sub-conveyance unit 15, and excites the motor, thereby fixing the sheet 20a located in the main conveyance section.

[0049] Next, in S100, the conveyance control unit 207 performs a position adjustment determination to determine whether or not prior position adjustment of the dancer roller 30 is necessary. Because the slack of the sheet 20a in the feeding section varies depending on the position of the dancer roller 30, the position adjustment determination is synonymous with a slack adjustment determination to determine whether or not the slack of the sheet 20a is appropriate.

[0050] In the first embodiment, the position adjustment determination is made based on the position information of the dancer roller 30 acquired by the roller position sensor 31. If the dancer roller 30 is located within the predetermined target range RG, the transport control unit 207 determines that position adjustment (slack adjustment) is not necessary (NO in S100), and if not, determines that position adjustment (slack adjustment) is necessary (YES in S100). If the transport control unit 207 determines that position adjustment is necessary, it executes a first control to adjust the position of the dancer roller 30, and if it determines that position adjustment is not necessary, it executes a second control to drive the main transport unit 12 and the sub transport unit 15 to transport the sheet 20a without executing the first control.

[0051] The target range RG used for determining position adjustment is a predetermined range between a predetermined upper range limit RG1 and a predetermined lower range limit RG2. In the first embodiment, the target position PS1 of the dancer roller 30 is the center position of the target range RG. The target position PS1 is the center (intermediate position) between the physical upper limit (upper limit position PS2) and lower limit (lower limit position PS3) of the movable range of the dancer roller 30. In other words, in the first embodiment, the transport control unit 207 determines that position adjustment is necessary when the dancer roller 30 is away from a predetermined reference position (target position PS1) by a predetermined amount or more. Note that the target range RG (upper range limit RG1 and lower range limit RG2) and the target position The method for setting the position PS1 is not limited to this. For example, the target position PS1 does not have to be the center position of the target range RG.

[0052] First, the case where the second control is executed will be described. Fig. 7 is a view showing the dancer roller 30 positioned at the target position PS1, i.e., within the target range RG, as viewed in the direction of the rotation axis of the dancer roller 30 and the rolled sheet 20. When the conveyance start sequence has started and the dancer roller 30 is in the position shown in Fig. 7, it is determined in S100 that position adjustment is not necessary. If it is determined in S100 that position adjustment is not necessary, the process proceeds to S500 to execute the second control.

[0053] In S500, the conveyance control unit 207 starts feedback control to drive the feeding unit 10 so that the dancer roller 30 moves to the target position PS1. At this time, the conveyance control unit 207 drives the feeding unit 10 by feedback control (for example, PID control) using position information of the dancer roller 30 acquired by the roller position sensor 31. The feedback control is performed while the sheet 20a is being conveyed by the main conveyance unit 12 and the sub-conveyance unit 15.

[0054] Next, in S510, the conveyance control unit 207 starts the rotation of the main conveyance unit 12 and the sub-conveyance unit 15, and starts conveying the sheet 20a in the main conveyance section. At this time, the feeding unit 10 rotates in a first direction D1 to send the sheet 20a in the conveyance direction Dc, and the roller pair 12a of the main conveyance unit 12 and the roller pair 15a of the sub-conveyance unit 15 also rotate in a direction to convey the sheet 20a in the conveyance direction Dc.

[0055] When conveyance of the sheet 20a in the main conveyance section begins, the tension on the sheet 20a increases, causing the dancer roller 30 to move in a direction (upward in FIG. 7 ) that reduces the buffer (the distance to the upper limit position PS2). However, the feeder unit 10 controls the unwinding amount (feeding amount) of the roll sheet 20, so the dancer roller 30 remains near the target position. At this time, the conveyance control unit 207 controls the feeder unit 10 independently of the main conveyance unit 12 and the sub-conveyor unit 15. In this way, when the initial buffer of the dancer roller 30 is optimal, that is, when the position of the dancer roller 30 is near the target position PS1, the conveyance control unit 207 can start conveying the sheet 20a without adjusting the position of the dancer roller 30 in advance. Then, as the sheet 20a is conveyed, the position of the dancer roller 30 is appropriately adjusted by feedback control.

[0056] Then, in S520, the conveying speeds of the main conveying unit 12 and the sub-conveying unit 15 are accelerated to the target speed. Once the conveying speed has finished accelerating to the target speed, the conveying start sequence is ended, and the sheet 20a continues to be conveyed at the target speed. With this configuration, the main conveying unit 12 and the sub-conveying unit 15 convey the sheet 20a at the target speed, while the conveying speed of the sheet 20a by the feeding unit 10 is appropriately adjusted so that the dancer roller 30 is located at the target position PS1.

[0057] 8 is a view of the sheet 20a being transported at the target speed, viewed in the direction of the rotation axis of the dancer roller 30 and the roll sheet 20. The dancer roller 30, which was moved to the target position PS1 in S500, moves up and down while the sheet 20a is being transported, thereby preventing sagging of the sheet 20a. In this way, in the second control, the main transport unit 12 and the sub-transport unit 15 are driven by the drive means to start transporting the sheet 20a, without prior adjustment of the position of the dancer roller 30. Then, while the sheet 20a is being transported, control (feedback control) is performed to keep the position of the dancer roller 30 within the target range RG.

[0058] Next, a case where the first control is executed will be described. If it is determined in S100 that the dancer roller 30 is located outside the target range RG and position adjustment is necessary, the process proceeds to S200. In S200, the conveyance control unit 207 determines, based on the position information of the dancer roller 30 acquired by the roller position sensor 31, that the position of the dancer roller 30 is above the upper limit range RG1 (upper limit If the dancer roller 30 is positioned above the upper range limit RG1, i.e., if the answer is YES in S200, proceed to S210. On the other hand, if the dancer roller 30 is positioned at or below the upper range limit RG1, i.e., if the answer is NO in S200, proceed to S300.

[0059] 9 shows the dancer roller 30 at its upper limit position PS2, i.e., above the upper range limit RG1. At this time, the sheet 20a is tightly wound between the feeding section 10 and the main transport section 12 without any slack, and the tension of the sheet 20a pushes the dancer roller 30 up to the upper limit position PS2. In this case, the answer to S200 is YES.

[0060] After a YES determination is made in S200, in S210, the feeding unit 10 starts rotating at a constant speed in the first direction D1 (unwinding direction). At this time, the feeding unit 10 rotates in the first direction D1 while the roller pair 12a, 15a is controlled to stop rotating. As the feeding unit 10 rotates in the first direction D1, the sheet 20a is pulled out from the roll sheet 20 held in the feeding unit 10, the tension on the dancer roller 30 is weakened, and the dancer roller 30 descends. In other words, S210 is a step of adjusting the position of the dancer roller 30 before the roller pair 12a, 15a start conveying the sheet 20a. This position adjustment operation is performed while the roller pair 12a, 15a is not rotating.

[0061] After rotation begins in S210, in S400, the transport control unit 207 stops the rotation of the feeding unit 10 so that the moving dancer roller 30 stops at the target position PS1, completing the preliminary position adjustment operation. In other words, the dancer roller 30, which is in the state shown in Fig. 9, transitions to the state shown in Fig. 7 as a result of driving the feeding unit 10 in S210 and S400. After adjusting the position of the dancer roller 30 in S210 and S400, the process proceeds to S500, and after steps S510 and S520, the transport start sequence ends and the sheet 20a continues to be transported at the target speed.

[0062] After determining NO in S200, in S300 the conveyance control unit 207 determines whether the position of the dancer roller 30 is below the range lower limit RG2 (towards the lower limit position PS3) based on the position information of the dancer roller 30 acquired by the roller position sensor 31. If the dancer roller 30 is located below the range lower limit RG2, that is, if the result of S300 is YES, the process proceeds to S310. On the other hand, if the dancer roller 30 is located at or above the range lower limit RG2, that is, if the result of S300 is NO, the process proceeds to S500.

[0063] 10 shows the dancer roller 30 at its lowest position PS3, i.e., below the range lower limit RG2. At this time, there is slack in the sheet 20a between the feeding section 10 and the main transport section 12, and the dancer roller 30 is pressed down to the lowest position PS3 by the biasing force of the air cylinder 64. In this case, the answer is NO in S200 and YES in S300.

[0064] After a YES determination is made in S300, in S310, feeding unit 10 starts rotating at a constant speed in second direction D2 (winding direction). At this time, feeding unit 10 rotates in second direction D2 while roller pair 12a, 15a are controlled to stop rotating. As feeding unit 10 rotates in second direction D2, roll sheet 20 held in feeding unit 10 winds sheet 20a, the tension on dancer roller 30 increases, and dancer roller 30 rises. In other words, like S210, S310 is a step of adjusting the position of dancer roller 30 that is performed before conveyance of sheet 20a begins.

[0065] After the rotation starts in S310, the moving dancer roller 30 is moved to the target position in S400. The conveyance control unit 207 stops the rotation of the feeding unit 10 so that the sheet 20a stops at position PS1. That is, the dancer roller 30 in the state shown in Fig. 10 is transitioned to the state shown in Fig. 7 by driving the feeding unit 10 in S310 and S400. After adjusting the position of the dancer roller 30 in S310 and S400, the process proceeds to S500, and after steps S510 and S520, the conveyance start sequence ends and the sheet 20a continues to be conveyed at the target speed.

[0066] On the other hand, after a NO determination is made in S300, the process proceeds to S500. In other words, it is determined that prior position adjustment of the dancer roller 30 is unnecessary, and feedback control is initiated. The process proceeding from S300 to S500 is also included in the second control. In the first embodiment, if the determination in S100 is YES (the dancer roller 30 is outside the target range RG) and the determination in S200 is NO (the dancer roller 30 is not above the range upper limit RG1), the determination in S300 will not be NO. Therefore, the determination in S300 may be omitted, and if the determination in S200 is NO, the process may proceed directly to S310, where rotation of the feeding section 10 in the second direction D2 is started.

[0067] In this way, in the first control, the process proceeds to S210 or S310, and before the roller pairs of the main conveyance unit 12 or the sub-conveyance unit 15 are rotationally driven, the first drive means drives the feeding unit 10 to adjust the position of the dancer roller 30. Specifically, control is executed to drive the feeding unit 10 and move the dancer roller 30, which is positioned outside the target range RG, to the target position PS1. Then, after the position adjustment of the dancer roller 30 has been performed (after the first control has been performed), the second control is started to start conveying the sheet 20a. In the first embodiment, whether to perform the first control or the second control without performing the first control is determined based on the detection result of the roller position sensor 31, which is a position detection unit.

[0068] In the control example shown in FIG. 6, only the position control of the dancer roller 30 in the feeding section has been described. However, the position control of the dancer roller 40 in the winding section may also be performed in parallel. That is, in the first control, the position of the dancer roller 40 may be adjusted in advance, similar to that of the dancer roller 30. The position control of the dancer roller 40 is performed by controlling the rotational drive of the winding section 17, not the feeding section 10. That is, the position adjustment determination as to whether the position control of the dancer roller 40 is necessary may be performed based on the detection result of the roller position sensor 41. When the dancer roller 40 is located above the upper range limit RG1, the winding section 17 rotates in the third direction D3, moving the sheet 20a in the opposite direction to the conveying direction Dc and lowering the dancer roller 40. When the dancer roller 40 is located below the lower range limit RG2, the winding section 17 rotates in the fourth direction D4, moving the sheet 20a in the conveying direction Dc and raising the dancer roller 40. With this configuration, in the first control, it is possible to make a pre-adjustment so that the dancer roller 30 or the dancer roller 40 that is positioned outside the target range is moved to the target position.

[0069] Furthermore, the target ranges RG used for controlling the positions of dancer rollers 30 and 40 do not necessarily have to be set to the same value, and separate ranges, upper and lower limits may be set for each. Furthermore, the position control of dancer roller 30 and the position control of dancer roller 40 may be performed in parallel or sequentially.

[0070] As described above, the configuration of the first embodiment makes it possible to move the dancer rollers 30, 40, which are located outside the target range RG, into the target range RG before feedback control. Therefore, since the occurrence of upward or downward contact of the dancer rollers 30, 40 can be suppressed, it is possible to achieve stable sheet conveyance while suppressing instability of sheet conveyance and excessive tension. Furthermore, since conveyance of the sheet 20a can be started without reducing the conveyance speed of the sheet 20a, it is possible to suppress delays in the start of sheet conveyance.

[0071] Second Embodiment Next, a second embodiment of the present invention will be described. The second embodiment differs from the first embodiment in the method of determining position adjustment at S100 in FIG. 6. Only the differences between the configuration of the second embodiment and the configuration of the first embodiment will be described below. Components in the second embodiment that are similar to those in the first embodiment will be assigned the same reference numerals and will not be described again.

[0072] In the first embodiment, in step S100 (position adjustment determination) of the conveyance start sequence, the determination is made based on the position information of the dancer roller 30. In contrast, in the second embodiment, the determination is made based on a target speed, which is a target value of the conveyance speed at which the main conveyance unit 12 and the sub-conveyance unit 15 convey the sheet 20a. The target speed is a target value of the rotational speed of the roller pairs 12a and 15a that constitute the main conveyance unit 12 and the sub-conveyance unit 15. However, the target value may also be the moving speed of the sheet 20a conveyed by the roller pairs 12a and 15a. In other words, in the second embodiment, the conveyance control unit 207 determines that position adjustment is necessary when the target speed of the roller pairs 12a and 15a is equal to or greater than a predetermined threshold. The conveyance start sequence in the second embodiment will be described below, focusing on the differences from the first embodiment.

[0073] In S100, the conveyance control unit 207 determines whether position adjustment of the dancer roller 30 is necessary before feedback control (S500) based on the target speeds of the main conveyance unit 12 and the sub-conveyance unit 15. Specifically, if the target speed is lower than a predetermined threshold, position adjustment is determined to be unnecessary (NO in S100). If the target speed is equal to or higher than the predetermined threshold, position adjustment is determined to be necessary (YES in S100). The predetermined threshold can be determined based on, for example, the drive conditions during sheet conveyance, such as the preset rotation speed of the feed unit 10, and the configuration of the sheet conveyance path. Note that in the second embodiment, determining that position adjustment is necessary in S100 does not necessarily mean that advance position adjustment of the dancer roller 30 is performed. If position adjustment is determined to be necessary in S100, a new determination is made as to whether position adjustment is necessary based on the position information of the dancer roller 30. In other words, even if the result in S100 is YES, advance position adjustment of the dancer roller 30 may not be performed.

[0074] If the result in S100 is NO, the process proceeds to S500, where feedback control is initiated to adjust the position of the dancer roller 30 while the sheet is being conveyed, and then the main conveyance unit 12 and the sub-conveyance unit 15 are driven to start sheet conveyance. At this time, the target speed of the main conveyance unit 12 and the sub-conveyance unit 15 is lower than a predetermined threshold value and is sufficiently slow compared to the rotation speed of the feeding unit 10. Therefore, even if sheet conveyance by the main conveyance unit 12 and the sub-conveyance unit 15 is started with the dancer roller 30 positioned outside the target range RG, the position of the dancer roller 30 is adjusted by feedback control, so there is little risk of the dancer roller 30 sticking up or down.

[0075] If the answer is YES in S100, the process proceeds to S200, where a determination is made based on the position information of the dancer roller 30. If the target speed is equal to or greater than a predetermined threshold, and sheet conveyance is started with the dancer roller 30 positioned outside the target range RG, there is a high possibility that overloading or underloading will occur even if feedback control is performed. Therefore, if the target speed is equal to or greater than the predetermined threshold, a determination is made regarding the position of the dancer roller 30 in S200 or S300, and the position of the dancer roller 30 is adjusted as necessary. In other words, in the second embodiment, if the target speeds of the main conveyance unit 12 and the sub-conveyance unit 15 are equal to or greater than a predetermined threshold, a determination is made as to whether to perform the first control or the second control based on the detection result of the roller position sensor 31.

[0076] In the above example, the position adjustment determination is performed based on the target speed of the main conveyor 12 and the sub-conveyor 15, but the present invention is not limited to this configuration. For example, instead of the target speed, the acceleration until the target speed is reached when the roller pairs 12a, 15a of the main conveyor 12 and the sub-conveyor 15 start to rotate may be used. If the acceleration is sufficiently slow, even if the dancer roller Even if sheet conveyance is started with the dancer roller 30 positioned outside the target range RG, the position of the dancer roller 30 is adjusted by feedback control, so there is little risk of upward or downward contact occurring. In other words, in the second embodiment, the conveyance control unit 207 may be configured to determine that position adjustment is necessary when the acceleration until the roller pair 12a, 15a reaches the target speed is equal to or greater than a predetermined threshold.

[0077] As described above, the configuration of the second embodiment allows a position adjustment determination to be made as to whether or not the position of the dancer roller 30 needs to be adjusted, based on the drive conditions during sheet transport of the main transport unit 12 and the sub-transport unit 15. Furthermore, in this example, position control of the dancer roller 40 can also be performed in the same manner as for the dancer roller 30. That is, before feedback control, it is possible to move the dancer rollers 30, 40, which are located outside the target range RG, into the target range RG. This prevents the dancer rollers 30, 40 from tipping upward or downward, thereby achieving stable sheet transport while preventing instability and excessive tension in sheet transport. Furthermore, because the transport of the sheet 20a can be started without reducing the transport speed of the sheet 20a, a delay in the start of sheet transport can be prevented.

[0078] Third Embodiment Next, a third embodiment of the present invention will be described. The third embodiment differs from the first embodiment in the method of determining position adjustment at S100 in FIG. 6. Only the differences between the configuration of the third embodiment and the configuration of the first embodiment will be described below. Components in the third embodiment that are similar to those in the first embodiment will be assigned the same reference numerals and will not be described again.

[0079] The recording device 90 according to the third embodiment further includes a change detection unit that detects change of the rolled sheet 20 in the feeding unit 10. The change detection unit can be provided, for example, at the attachment portion of the rolled sheet 20 in the feeding unit 10, and can use a known sensor that can detect attachment / detachment of the rolled sheet 20 to / from the bearing or the presence or absence of the rolled sheet 20 in the feeding unit 10.

[0080] The roll sheet 20 is replaced manually by the user, and the tension that the dancer roller 30 receives from the sheet 20a after replacement is unlikely to be constant, and the position of the dancer roller 30 is also unstable. Therefore, in the third embodiment, in the sheet conveyance start sequence immediately after the roll sheet 20 is replaced, the position of the dancer roller 30 is adjusted in advance before sheet conveyance begins.

[0081] In the first embodiment, in S100 (position adjustment determination) of the conveyance start sequence, the determination is made based on the position information of the dancer roller 30. On the other hand, in the third embodiment, the determination is made based on the detection result of the change detection unit. That is, in the third embodiment, the conveyance control unit 207 determines that position adjustment is necessary when the change detection unit detects a change of the roll sheet 20. The conveyance start sequence in the third embodiment will be described below, focusing on the differences from the first embodiment.

[0082] In S100, the conveyance control unit 207 determines whether or not position adjustment of the dancer roller 30 is necessary before feedback control (S500) based on the detection result of the change detection unit. Specifically, if the change detection unit has not detected that the roll sheet 20 has been changed in the feeding unit 10 since the last sheet conveyance stop, it determines that position adjustment is unnecessary (NO in S100). On the other hand, if the change detection unit has detected that the roll sheet 20 has been changed in the feeding unit 10 since the last sheet conveyance stop, it determines that position adjustment is necessary (YES in S100). Note that in the third embodiment, determining that position adjustment is necessary in S100 does not necessarily mean that advance position adjustment of the dancer roller 30 is performed. If it is determined that position adjustment is necessary in S100, the dancer roller 30 is subsequently adjusted. Whether or not position adjustment is necessary is determined again based on the position information of the dancer roller 30. In other words, even if the answer is YES in S100, there is a possibility that the position of the dancer roller 30 will not be adjusted in advance.

[0083] If the answer is NO in S100, the process proceeds to S500, where feedback control is initiated to adjust the position of the dancer roller 30 while the sheet is being conveyed, after which the main conveyance unit 12 and the sub-conveyance unit 15 are driven to start sheet conveyance. At this time, the rolled sheet 20 has not been replaced since the previous sheet conveyance, so there is less chance that the dancer roller 30 will be positioned outside the target range RG than if the rolled sheet 20 had been replaced. Therefore, even if sheet conveyance by the main conveyance unit 12 and the sub-conveyance unit 15 is started without prior position adjustment of the dancer roller 30, the position of the dancer roller 30 is adjusted by feedback control, and there is less chance that upside or downside will occur.

[0084] If the answer is YES in S100, the process proceeds to S200, where a determination is made based on the position information of the dancer roller 30. If the roll sheet 20 has been replaced immediately before, the dancer roller 30 may be positioned outside the target range RG, which may result in upward or downward sticking when sheet conveyance begins. Therefore, the position of the dancer roller 30 is determined in S200 and S300, and the position of the dancer roller 30 is adjusted as necessary. In other words, in the third embodiment, if the replacement detection unit detects the replacement of the roll sheet 20, a determination is made as to whether to execute the first control or the second control based on the detection result of the roller position sensor 31.

[0085] As described above, the configuration of the third embodiment allows a position adjustment determination as to whether or not the position of the dancer roller 30 needs to be adjusted based on the roll sheet 20 replacement information in the feeding unit 10. Furthermore, in this example, by providing a replacement detection unit in the winding unit 17, the position of the dancer roller 40 can be controlled in the same way as the dancer roller 30. In other words, before feedback control, it is possible to move the dancer rollers 30, 40 that are outside the target range RG into the target range RG. This prevents the dancer rollers 30, 40 from sticking up or down, thereby achieving stable sheet transport while preventing instability and excessive tension in sheet transport. Furthermore, because sheet 20a can be started without reducing the transport speed of the sheet 20a, delays in the start of sheet transport can be prevented.

[0086] <Other embodiments> The method for determining whether or not to adjust the position of the dancer roller in the sheet conveyance start sequence is not limited to the methods described in the above embodiments. For example, consider a configuration in which the recording device 90 is provided with an operation unit, such as a conveyance start button, that the user can operate to start conveying the sheet 20a. In such a configuration, when the user operates the operation unit to start sheet conveyance (start the sheet conveyance start sequence), the position adjustment determination (S100 in FIG. 6) may determine that the position of the dancer roller 30 needs to be adjusted.

[0087] In addition, in each of the above-described embodiments, the position adjustment determination and the position adjustment operation are performed in the sheet conveyance start sequence, but this is not limited to such a configuration. As long as the sheet 20a is nipped between the non-rotating roller pair 12a and 15a, the dancer roller position adjustment determination and the position adjustment operation can be performed at any timing.

[0088] Furthermore, in applying the present invention, the processes described in the above embodiments as being performed by one device may be shared and executed by multiple devices. Alternatively, the processes described as being performed by different devices may be executed by one device. In a computer system, the hardware configuration for implementing each function can be flexibly changed.

[0089] The disclosure of this embodiment includes the following configuration. (Configuration 1) a holding section that holds a roll sheet on which a sheet is wound; a first driving means for rotating the roll sheet held by the holding portion in a first direction and a second direction opposite to the first direction; a pair of rollers that sandwich a continuous sheet from the roll sheet held by the holding unit; a second driving means for driving the pair of rollers to rotate; a dancer roller configured to be linearly movable in a movement direction intersecting the sheet conveyance direction between the holding portion and the roller pair in the sheet conveyance direction and to come into contact with the sheet; a position detection unit that detects the position of the dancer roller in the movement direction; a control unit that executes a first control to adjust the position of the dancer roller by the first driving means before starting conveyance of the sheet by the second driving means based on a detection result of the position detection unit, and a second control to start conveyance of the sheet by the second driving means without executing the first control; A sheet conveying device comprising: (Configuration 2) The control unit is configured to be able to perform a position adjustment determination as to whether or not the position of the dancer roller needs to be adjusted, and determines whether to perform the first control or the second control based on the result of the position adjustment determination. (Configuration 3) the first control includes control for moving a position of the dancer roller that is positioned outside a predetermined target range to a predetermined target position, 3. The sheet conveying device according to configuration 1 or 2, wherein the second control includes control for keeping the position of the dancer roller within the predetermined target range. (Configuration 4) 4. The sheet conveying device according to any one of configurations 1 to 3, wherein the control unit controls the second driving means in the first control so that the pair of rollers stops rotating. (Configuration 5) The sheet conveying device according to any one of configurations 1 to 4, characterized in that, in the second control, the control unit drives the roll sheet held in the holding unit to rotate by the first driving means, and drives the pair of rollers to rotate by the second driving means. (Configuration 6) 6. The sheet conveying device according to any one of configurations 1 to 5, wherein the control unit starts the second control after executing the first control. (Configuration 7) The sheet conveying device according to any one of configurations 1 to 6, wherein the control unit executes the first control when the dancer roller is separated from a predetermined reference position by a predetermined amount or more. (Configuration 8) The sheet conveying device according to any one of configurations 1 to 6, characterized in that the control unit determines whether to perform the first control or the second control based on the detection result when the target value of the conveying speed at which the roller pair conveys the sheet is equal to or greater than a predetermined threshold value. (Configuration 9) When the acceleration until the target value of the conveying speed at which the pair of rollers conveys the sheet is reached is equal to or greater than a predetermined threshold, the control unit executes the first control based on the detection result. 7. The sheet conveying device according to any one of configurations 1 to 6, wherein it is determined whether or not the second control is to be executed. (Configuration 10) a change detection unit for detecting that the roll sheet has been changed to the holding unit; The sheet conveying device according to any one of configurations 1 to 6, characterized in that when the change detection unit detects a change of the roll sheet, the control unit determines whether to execute the first control or the second control based on the detection result. (Configuration 11) The sheet conveying device further includes an operating unit for driving the pair of rollers to start conveying the sheet, The sheet conveying device according to any one of configurations 1 to 6, characterized in that when a user operates the operation unit to start conveying a sheet, the control unit determines whether to execute the first control or the second control based on the detection result. (Configuration 12) The sheet conveying device described in any one of configurations 1 to 11, characterized in that the control unit adjusts the position of the dancer roller by rotating the roll sheet held by the holding unit while the sheet is nipped by the roller pair. (Configuration 13) 13. The sheet conveying device according to any one of configurations 1 to 12, further comprising a regulating member that regulates a movable range of the dancer roller in the movement direction. (Configuration 14) a sheet conveying device according to any one of configurations 1 to 13; a recording unit that records an image on a sheet conveyed by a sheet conveying device; A recording device comprising: (Configuration 15) 15. The recording apparatus according to configuration 14, wherein the holding unit is a feeding unit for feeding a sheet toward the recording unit. (Configuration 16) 15. The recording apparatus according to configuration 14, wherein the holding section is a winding section for winding up the sheet on which the image has been recorded by the recording section. (Configuration 17) When the holding unit is a first holding unit, the roller pair is a first roller pair, the dancer roller is a first dancer roller, and the position detection unit is a first position detection unit, a second holding unit provided on the opposite side of the recording unit from the first holding unit in the transport direction; a third driving means for rotating the roll sheet held by the second holding portion in a third direction and a fourth direction opposite to the third direction; a second roller pair that holds the sheet between the recording unit and the second holding unit in the conveyance direction; a fourth driving means for driving the second roller pair to rotate; a second dancer roller configured to be linearly movable in a movement direction intersecting the conveyance direction between the second holding portion and the second roller pair in the conveyance direction and to come into contact with the sheet; a second position detection unit that detects the position of the second dancer roller in the movement direction; Further provided with The recording device according to any one of configurations 14 to 16, wherein the control unit, in the first control, adjusts the position of the second dancer roller by the third driving means before starting to transport the sheet by the third driving means. [Explanation of symbols]

[0090] 10...feeding section (holding section), 12a...roller pair, 20...roll sheet, 20a...sheet, 30... Dancer roller, 31... Roller position sensor (position detection unit), 207... Conveyance control unit (control unit), D1... First direction, D2... Second direction

Claims

1. a holding section that holds a roll sheet on which a sheet is wound; a first driving means for rotating the roll sheet held by the holding portion in a first direction and a second direction opposite to the first direction; a pair of rollers that sandwich a continuous sheet from the roll sheet held by the holding unit; a second driving means for driving the pair of rollers to rotate; a dancer roller configured to be linearly movable in a movement direction intersecting the sheet conveyance direction between the holding portion and the roller pair in the sheet conveyance direction and to come into contact with the sheet; a position detection unit that detects the position of the dancer roller in the movement direction; a control unit that executes a first control for adjusting the position of the dancer roller by the first driving means before starting conveyance of the sheet by the second driving means based on a detection result of the position detection unit, and a second control for starting conveyance of the sheet by the second driving means without executing the first control; A sheet conveying device comprising:

2. The control unit is configured to perform a position adjustment determination as to whether or not the position of the dancer roller needs to be adjusted, and determines whether to perform the first control or the second control based on the result of the position adjustment determination.

3. the first control includes control for moving a position of the dancer roller that is positioned outside a predetermined target range to a predetermined target position, 2. The sheet conveying device according to claim 1, wherein the second control includes a control for keeping the position of the dancer roller within the predetermined target range.

4. 2. The sheet conveying device according to claim 1, wherein the control unit controls the second driving means in the first control so that the pair of rollers stops rotating.

5. The sheet conveying device according to claim 1, characterized in that, in the second control, the control unit drives the roll sheet held in the holding unit to rotate by the first driving means, and drives the pair of rollers to rotate by the second driving means.

6. The sheet conveying device according to claim 1 , wherein the control unit starts the second control after executing the first control.

7. 2. The sheet conveying device according to claim 1, wherein the control unit executes the first control when the dancer roller is spaced apart from a predetermined reference position by a predetermined amount or more.

8. The sheet conveying device according to claim 1, characterized in that the control unit determines whether to perform the first control or the second control based on the detection result when the target value of the conveying speed at which the roller pair conveys the sheet is equal to or greater than a predetermined threshold value.

9. The sheet conveying device according to claim 1, characterized in that the control unit determines whether to perform the first control or the second control based on the detection result when the acceleration until the roller pair reaches the target value of the conveying speed at which the sheet is conveyed is equal to or greater than a predetermined threshold.

10. a change detection unit for detecting that the roll sheet has been changed to the holding unit; When the change detection unit detects a change of the roll sheet, the control unit:

2. The sheet conveying device according to claim 1, wherein a determination is made as to whether the first control or the second control is to be performed based on the detection result.

11. The sheet conveying device further includes an operating unit for driving the pair of rollers to start conveying the sheet, The sheet conveying device according to claim 1, wherein the control unit determines whether to execute the first control or the second control based on the detection result when a user operates the operation unit to start sheet conveyance.

12. 2. The sheet conveying device according to claim 1, wherein the control unit adjusts the position of the dancer roller by rotating the roll sheet held by the holding unit while the sheet is nipped by the pair of rollers.

13. 2. The sheet conveying device according to claim 1, further comprising a regulating member that regulates a movable range of the dancer roller in the movement direction.

14. a sheet conveying device according to any one of claims 1 to 13; a recording unit that records an image on a sheet conveyed by a sheet conveying device; A recording device comprising:

15. 15. The recording apparatus according to claim 14, wherein the holding unit is a feeding unit for feeding a sheet toward the recording unit.

16. 15. The recording apparatus according to claim 14, wherein the holding section is a winding section for winding up the sheet on which the image has been recorded by the recording section.

17. When the holding unit is a first holding unit, the roller pair is a first roller pair, the dancer roller is a first dancer roller, and the position detection unit is a first position detection unit, a second holding unit provided on the opposite side of the recording unit from the first holding unit in the transport direction; a third driving means for rotating the roll sheet held by the second holding portion in a third direction and a fourth direction opposite to the third direction; a second roller pair that holds the sheet between the recording unit and the second holding unit in the conveyance direction; a fourth driving means for driving the second roller pair to rotate; a second dancer roller configured to be linearly movable in a movement direction intersecting the conveyance direction between the second holding portion and the second roller pair in the conveyance direction and to come into contact with the sheet; a second position detection unit that detects the position of the second dancer roller in the movement direction; Further provided with 15. The recording apparatus according to claim 14, wherein the control unit adjusts the position of the second dancer roller by the third driving means before the third driving means starts to transport the sheet in the first control.

Images