JP2022028459A - Tension control device for transported object, transported object transportation device, liquid discharge device, and image formation device - Google Patents

Abstract

To provide a tension control device for a transported object which can generate uniform tension even when a residual amount of a sheet-like medium fed from a roll medium changes, and has high durability.SOLUTION: A tension control device for a transported object includes first rotation means rotated by driving force of a driving source, second rotation means rotated according to transportation of the transported object wound in a roll shape, and torque generation means for generating a torque for decelerating rotation speed in the second rotation means according to a difference in rotation angles between the second rotation means and the first rotation means, in which the torque generation means includes elastic connection means for connecting an elastic body so as to transmit driving force from the first rotation means to the second rotation means.SELECTED DRAWING: Figure 5

Description

The present invention relates to a tension control device for a transported object, a transported object transport device, a liquid discharge device, and an image forming device.

There are known a transfer device in which a sheet-shaped medium is wound into a roll and the roll medium is rotated and conveyed to an image forming unit, and an image forming device including the transfer device. The above-mentioned transport device includes a tension control device that generates tension in the medium by applying a constant torque to the core of the roll media and controls the posture of the medium during transport so as to be maintained in a predetermined state. There is something to prepare for. In an inkjet image forming apparatus equipped with a liquid ejection device that ejects liquid ink to a medium in an image forming portion and forms an image from an image of droplets, the stability of the relative distance between the image forming portion and the medium is the image quality. Maintaining the tension of the medium is of particular importance because it affects the image.

In order to keep the tension generated in the medium constant, the torque must be changed according to the roll diameter of the roll media rotated by the core. Therefore, as a mechanism for varying the torque in order to keep the tension constant even if the state of the medium changes, a technique for mechanically controlling the torque by bringing the hemispherical friction members into contact with each other is disclosed ( See Patent Document 1).

The technique disclosed in Patent Document 1 requires a plurality of actuators for generating torque and an actuator for varying the deceleration mechanism in order to generate torque for keeping the tension constant. In addition, a friction drive unit is required for the mechanism for varying the torque, and there is a problem to be solved in terms of durability performance.

It is an object of the present invention to provide a tension control device for an object to be transported, which can generate uniform tension even if the remaining amount of the sheet-like medium sent out from the roll media changes and has high durability. And.

In order to solve the above technical problems, one aspect of the present invention relates to a tension control device for an object to be transported, which comprises a first rotating means that is rotated by the driving force of a drive source and a roll-shaped object to be conveyed. A second rotating means that rotates according to the above, and a torque generating means that generates a torque for decelerating the rotation speed in the second rotating means according to the difference in rotation angle between the second rotating means and the first rotating means. The torque generating means includes an elastic connecting means for connecting an elastic body so as to transmit the driving force from the first rotating means to the second rotating means.

According to the present invention, uniform tension can be generated even if the remaining amount of the sheet-like medium sent out from the roll media changes, and the sheet-like medium has high durability.

The perspective view which shows the appearance of embodiment of the image forming apparatus which concerns on this invention. Internal structure diagram of an inkjet printer as an example of an image forming apparatus. The structural drawing of the image forming part provided in the said inkjet printer. A partial structural diagram of a structure illustrating an embodiment of a medium transfer device according to the present invention. The structural drawing which exemplifies the embodiment of the tension control apparatus for an object to be conveyed which concerns on this invention. The figure which illustrates the state of the torque control in the said tension control device for an object to be conveyed. The figure which illustrates the state of the torque control in the said tension control device for an object to be conveyed. The graph which shows the example of the data table for torque control in the said tension control device for an object to be conveyed. The graph which shows another example of the data table for torque control in the said tension control device for an object to be conveyed. The hardware configuration diagram of the control unit in the tension control device for the object to be transported.

Hereinafter, embodiments of the tension control device for the transported object, the transported object transport device, the liquid discharge device, and the image forming apparatus of the present invention will be described with reference to the drawings.

[Image forming device]
FIG. 1 is a diagram showing a schematic configuration of an example of an inkjet printer 100, which is a kind of image forming apparatus according to the present invention and is also an embodiment of a liquid ejection device, partially seen through from diagonally upward. FIG. 2 is a schematic view showing the inkjet printer 100 from the side surface direction. FIG. 3 is a plan view showing a part of the main part of the image forming portion provided in the inkjet printer 100. The embodiment of the transport device according to the present invention can be applied to the inkjet printer 100.

As shown in FIG. 1, the inkjet printer 100 has a device main body 101 and a sheet 120 as a sheet-like medium from a roll body 112 as a roll-shaped object to be transported, which is arranged under the device main body 101. A sheet supply device 102 as a medium supply device for supplying the sheet 120 and a sheet winding device 103 as a medium winding device for winding the sheet 120 are provided. Since the sheet 120 is conveyed by the sheet supply device 102 and the sheet winding device 103, these correspond to the embodiment of the transfer device according to the present invention. To the sheet supply device 102 and the sheet take-up device 103, a transfer device provided with a tension control device for an object to be conveyed according to the present invention can be applied so as to generate a constant tension in the sheet 120 to be conveyed. be.

The sheet 120 as an object to be transported is a medium that can be rolled into a roll, and includes, for example, paper, coated paper, cardboard, OHP, plastic film, prepreg, silver leaf, cloth, and the like. The sheet 120 is wound around a hollow shaft portion 115 as a winding core to form a roll body 112. The roll body 112 is rotatably held by the sheet supply device 102.

The sheet winding device 103 holds a hollow shaft portion 114 as a winding core for winding the sheet 120. The sheet 120 is conveyed to the image forming unit 104 by the conveying operation of the conveying means 21, which will be described later. Therefore, the sheet 120 is sent out from the sheet supply device 102 and is wound by the sheet winding device 103 via the conveying means 21.

It is necessary to generate a constant tension in the sheet 120 between the sheet supply device 102 and the sheet winding device 103 to maintain the state during transportation. Therefore, the sheet supply device 102 and the sheet winding device 103 are controlled so as to apply a constant torque to the winding core. The sheet supply device 102 and the sheet winding device 103 may be configured integrally with the device main body 101 instead of being separate.

The sheet supply device 102 supplies the sheet 120 to the inside of the device main body 101. Inside the apparatus main body 101, an image forming unit 104 that forms an image on the sheet 120 supplied in the transport direction indicated by the direction of the arrow B in FIG. 1 is arranged. In the image forming portion 104 included in the apparatus main body 101, a guide rod 1 and a guide stay 2 which are guide members are hung on both side plates, and a carriage 5 is attached to the guide rod 1 and the guide stay 2 as shown by an arrow A in FIG. It is movably supported in the main scanning direction indicated by the direction.

A main scanning motor 8 which is a drive source for reciprocating the carriage 5 is arranged on one side in the main scanning direction. A scanning timing belt 11 is hung between the drive pulley 9 rotationally driven by the main scanning motor 8 and the driven pulley 10 arranged on the other side in the main scanning direction. The belt holding portion of the carriage 5 is fixed to the scanning timing belt 11, and the carriage 5 is reciprocated in the main scanning direction by driving the main scanning motor 8.

The carriage 5 is equipped with a plurality of recording heads 6a to 6d in which a liquid discharge head and a head tank for supplying liquid to the head are integrated. Here, the recording heads 6a and the recording heads 6b to 6d are arranged so as to be displaced by one head (one nozzle row) in the sub-scanning direction orthogonal to the main scanning direction. Further, the recording heads 6a to 6d are mounted with a nozzle array composed of a plurality of nozzles for ejecting droplets arranged in the sub-scanning direction and with the droplet ejection direction facing downward.

Further, each of the recording heads 6a to 6d has two rows of nozzle rows. Then, for the recording heads 6a and 6b, black droplets of the same color are ejected from any nozzle row. The recording head 6c ejects cyan droplets from one nozzle row, and the other nozzle row is an unused nozzle row. Further, the recording head 6d ejects yellow droplets from one nozzle row and magenta droplets from the other nozzle row.

As a result, for monochrome images, the recording heads 6a and 6b can be used to form an image having a width of two heads in the main scan of one scan, and for color images, for example, recording heads 6b to 6d can be used. Image formation can be performed. The head configuration is not limited to this, and a plurality of recording heads may be arranged side by side in the main scanning direction.

Further, a carriage encoder sheet 12 is arranged along the moving direction of the carriage 5, and the carriage 5 is provided with a carriage encoder sensor 13 for reading the carriage encoder sheet 12. The linear encoder 14 is configured by the carriage encoder sheet 12 and the carriage encoder sensor 13. The position and speed of the carriage 5 can be detected by the output from the linear encoder 14.

In the recording area of the main scanning area of the carriage 5, the sheet 120 is fed from the sheet supply device 102. After that, the sheet 120 is intermittently conveyed by the conveying means 21 (see FIG. 2) in the sub-scanning direction (paper conveying direction) orthogonal to the main scanning direction of the carriage 5. Each color ink is supplied to the head tanks of the recording heads 6a to 6d from the ink cartridge 60, which is a main tank that is replaceably mounted on the apparatus main body 101, via a supply tube. Further, on one side of the carriage 5 in the main scanning direction, a maintenance / recovery mechanism 80 for maintaining / recovering the recording heads 6a to 6d is arranged on the side of the transport guide member 25.

The transport means 21 as a resist roller shown in FIG. 2 is composed of a transport roller 23 for transporting the sheet 120 to be fed from the sheet supply device 102 and a pressure roller 24 arranged to face the transport roller 23. The sheet 120 is conveyed in the direction of arrow B by the rotation of the transfer roller 23 in a state of being sandwiched between the transfer roller 23 and the pressure roller 24. Further, a transport guide member 25 having a plurality of suction holes formed on the downstream side of the transport means 21 and a suction fan 26 as suction means for sucking from the suction holes of the transport guide member 25 are provided. Further, on the downstream side of the transport means 21, a cutter 27 as a cutting means for cutting the sheet 120 image-formed by the recording heads 6a to 6d to a predetermined length is arranged.

In the sheet supply device 102, the sheet 120 is wound around a winding core (hollow shaft portion 115) such as a paper tube, and the end is fixed to the hollow shaft portion 115 by adhesion such as gluing, or the end of the sheet 120 is a hollow shaft. Any non-fixed material that is not adhered to the portion 115 can be attached.

As shown in FIG. 2, on the device main body 101 side, the guide member 130 for guiding the sheet 120 pulled out from the roll body 112 of the sheet supply device 102 and the sheet 120 after suction are guided downstream of the transport guide member 25. A paper ejection guide member 131 is arranged. The sheet winding device 103 holds a winding core (hollow shaft portion 114) of a paper tube or the like, and the tip of the sheet 120 is adhered to the winding core (hollow shaft portion 114) with a tape or the like to hold the sheet 120 so that it can be wound.

As shown in FIG. 3, the inkjet printer 100 having such a configuration moves the carriage 5 in the main scanning direction (direction of arrow A in FIG. 3) at the time of image formation, and is pulled out from the roll body 112 of the sheet supply device 102. The sheet 120 guided along the guide member 130 is intermittently conveyed by the conveying means 21 in the sub-scanning direction (direction of arrow B in FIG. 3). Then, by driving the recording heads 6a to 6d according to the image information (printing information) and ejecting the droplets, a required image is formed on the sheet 120. The image-formed sheet 120 is guided by the paper ejection guide member 131 and wound around the hollow shaft portion 114 in the sheet winding device 103. The sheet 120 on the transport roller 23 depends on the torque applied to the winding core by each of the sheet supply device 102 side and the sheet winding device 103 side (torque for rotating the winding core in the direction opposite to the transport direction of the sheet 120). It is transported in a state where tension is generated. The magnitude of each tension at this time affects the transport accuracy.

[Embodiment of transport device]
FIG. 4 is a diagram showing an external configuration of a sheet supply device 102 as a transfer device provided in the above-mentioned image forming device from an obliquely upward direction. In the sheet supply device 102, the first guide 16 and the second guide 17 are provided on the stand main body 15 so as to extend in the longitudinal direction of the roll body 112 in parallel with each other. The longitudinal direction of the roll body 112 is the direction of arrow A in FIG. The first holding unit 18 and the second holding unit 19 are supported on the first guide 16 and the second guide 17 so as to face each other and move in the direction of the arrow A, respectively.

The first holding unit 18 and the second holding unit 19 are arranged at the ends of the first guide 16 and the second guide 17 with the first guide 16 as the main reference and the second guide 17 as the secondary reference. Each of the first guide 16 and the second guide 17 is provided with a roll body holding device 30. As illustrated in FIG. 4, the roll body holding device 30 is arranged directly above the first guide 16. The roll body 112 is rotatably held by fitting the roll body holding devices 30 of the first holding unit 18 and the second holding unit 19 into the hollow shaft portion 115 of the roll body 112.

The same configuration as the sheet supply device 102 described above is also provided in the sheet winding device 103. Since the roll diameter of the roll body 112 changes at any time depending on the transfer amount of the sheet 120, it is difficult to obtain high transfer accuracy unless the tension can be appropriately adjusted each time the sheet 120 is conveyed at the time of image formation. Therefore, the sheet supply device 102 and the sheet winding device 103 according to the present embodiment each include a roll body holding device 30 as a tension control device for the object to be transported.

[Tension control device for objects to be transported]
FIG. 5 is a structural diagram illustrating the structure of the roll body holding device 30 as the tension control device for the object to be transported. As shown in FIG. 5, the roll body holding device 30 includes a motor 301 as a drive source, a motor shaft pulley 302, a tension adjustment timing belt 303, a drive shaft pulley 304, a drive shaft 305 as a first rotation means, and an angle difference detection. Drive-side encoder sensor 306 as the first encoder sensor as a means, drive-side encoder sheet 307 as the first encoder sheet, tensioner 308 as the torque generating means, spring 309 as the elastic connecting means, driven as the second encoder sensor. It includes a side encoder sensor 310, a driven side encoder sheet 311 as a second encoder sheet, a flange 312, and a driven shaft 314 as a second rotation means.

The sheet 120 is sent out by the transport means 21 from the roll body 112 held in the first holding unit 18 and the second holding unit 19 described above. The sheet 120 is sent out by rotating the roll body 112 shown in FIG. As shown in FIG. 5, when the roll body 112 rotates in a predetermined direction, the flange 312 holding the hollow shaft portion 115 also rotates in the same direction as the rotation direction of the roll body 112.

Since the flange 312 is attached to one end of the driven shaft 314 rotatably supported by the housing of the roll body holding device 30, the driven shaft 314 also rotates in the same direction as the roll body 112 rotates. Rotate. That is, the driven shaft 314 is configured to rotate at a predetermined speed by transporting the seat 120. At this time, the hollow shaft portion 114 of the sheet winding device 103 also rotates at a predetermined speed. As a result, the conveyed sheet 120 is wound up. When a torque in the direction of suppressing the rotation of the flange 312 is applied to the driven shaft 314, a force for suppressing the movement of the sheet 120 in the direction of being wound by the sheet winding device 103 is applied to the sheet 120. .. That is, tension can be generated in the seat 120 by applying a torque that reduces the rotation speed of the driven shaft 314 (torque in the direction opposite to the rotation of the driven shaft 314). Tension is generated between the transport means 21, the hollow shaft portion 115 and the hollow shaft portion 114.

A driven side encoder sheet 311 is fixed near the center of the driven shaft 314 in the longitudinal direction. The driven shaft 314 is supported by the housing of the roll body holding device 30 between the end portion where the flange 312 is fixed and the fixed position where the driven side encoder sheet 311 is fixed.

The driven side encoder sheet 311 rotates in the same direction and rotation amount as the rotation direction and rotation amount of the driven shaft 314, and the rotation direction and rotation amount of the driven side encoder sheet 311 are detected by the driven side encoder sensor 310. It is configured.

The rotation detection signal as the detection result of the driven side encoder sensor 310 is sent to the control unit 320, which will be described later. Therefore, the driven side encoder sheet 311, the driven side encoder sensor 310, and the control unit 320 can calculate the rotation amount of the driven shaft 314, that is, the rotation amount of the roll body 112, and the driven side rotation amount calculating means is configured. ..

The drive shaft 305 is arranged at a position separated from the driven shaft 314 in the axial direction of the driven shaft 314. The axis of the driven shaft 314 and the axis of the drive shaft 305 are in the same line shape.

A drive shaft pulley 304 is fixed to an end of the drive shaft 305 opposite to the end opposite to the driven shaft 314. A tension adjustment timing belt 303 is hung around the drive shaft pulley 304. Further, the tension adjusting timing belt 303 is also hung on the motor shaft pulley 302 fixed to the rotating shaft of the motor 301. Therefore, when the motor 301 is operated, the driving force thereof is transmitted to the drive shaft 305 via the tension adjustment timing belt 303. The drive shaft 305 rotates according to the amount of rotation of the motor 301.

A drive-side encoder sheet 307 is fixed near the center of the drive shaft 305 in the longitudinal direction. The drive shaft 305 is supported by the housing of the roll body holding device 30 between the fixed position of the drive shaft pulley 304 and the fixed position of the drive side encoder sheet 307. Since the drive-side encoder sheet 307 is fixed to the drive shaft 305 in a state of being supported by the tension control unit 300, the drive-side encoder sheet 307 rotates with the rotation of the drive shaft 305. Therefore, the drive-side encoder sheet 307 rotates in the same direction as the rotation direction and rotation amount of the drive shaft 305. Since the rotation direction and rotation amount of the drive side encoder sheet 307 can be detected by the drive side encoder sensor 306, the rotation amount and rotation direction of the drive shaft 305 can be determined by the rotation detection signal from the drive side encoder sensor 306. ..

The rotation detection signal from the drive-side encoder sensor 306 is sent to the control unit 320, which will be described later. Therefore, the drive-side encoder sheet 307, the drive-side encoder sensor 306, and the control unit 320 configure a drive-side rotation amount calculation means for calculating the rotation amount of the drive shaft 305.

Of the ends of the drive shaft 305, the tensioner 308, which is a tension adjusting means and is a first connecting member, is fixed to the end opposite to the end to which the drive shaft pulley 304 is fixed. Further, the tensioner 308, which is a tension adjusting means and is a second connecting member, is also fixed to the other end of the driven shaft 314, that is, the end opposite to the end to which the flange 312 is fixed. The tensioner 308 fixed to the drive shaft 305 and the tensioner 308 fixed to the driven shaft 314 are both rectangular plate-shaped members, and are rotated by the rotation of the drive shaft 305 and the driven shaft 314, respectively.

The two tensioners 308 as the means for generating the difference in rotation angle are both plate-shaped members and are thin plates having a rectangular outer shape. The ends in the longitudinal direction facing each other are connected by a spring 309 as an elastic member. That is, the tensioner 308 fixed to the drive shaft 305 and the opposite ends of the tensioner 308 fixed to the driven shaft 314 are urged in a direction of being attracted by the spring 309, which is a spring member.

In this case, if the opposite ends of the tensioner 308 are closest to each other, for example, if the spring 309 is in the same posture position and the spring 309 is the most contracted, the direction of rotation between the drive shaft 305 and the driven shaft 314. The force to urge you does not work. When the drive shaft 305 is rotated in a certain direction by the motor 301 as a drive source, the spring 309 is extended. Since the spring 309 is a tension coil spring, it is stretched and at the same time tries to return to its original state by the restoring force. This restoring force (spring force) increases according to the size of the relative rotation angle difference between the opposing ends of the tensioner 308 depending on the amount of rotation of the drive shaft 305, and is in the opposite direction of the rotation direction due to the transportation of the seat 120. Generates a torque that gives a rotational force to.

In other words, when the drive shaft 305 is rotated to change the phase of the tensioner 308 on the drive shaft 305 side to form a rotation angle difference Δθ with respect to the tensioner 308 on the driven shaft 314 side, the tensioner 308 on the driven shaft 314 side is formed. The spring force of the spring 309 is applied to the spring 309, and the spring force applies a force to rotate in a predetermined direction. The direction of this force becomes a force in the direction opposite to the direction in which the driven shaft 314 rotates when the sheet 120 is conveyed by the conveying means 21. In other words, even if the driven shaft 314 rotates and the tensioner 308 on the driven shaft 314 side rotates with the rotation of the driven shaft 314, the tensioner 308 on the drive shaft 305 side is rotated in a certain direction, and the tensioners 308 are connected to each other. When a predetermined moving state (rotation angle difference Δθ) is formed, a torque corresponding to the spring force of the spring 309 is applied to the driven shaft 314.

As illustrated in FIG. 8, the spring force correlates with the magnitude of the difference in rotation angle (rotation angle difference Δθ) between the tensioner 308 on the drive shaft 305 side and the tensioner 308 on the driven shaft 314 side. The larger the rotation angle difference Δθ, the stronger the torque (F).

Subsequently, the relationship between the operation of the roll body holding device 30 and the tension generated in the sheet 120 will be described with reference to FIGS. 6 and 7. FIG. 6 illustrates a state in which the roll diameter on the sheet supply device 102 side is larger than the roll diameter on the sheet winding device 103 side. Further, FIG. 7 illustrates a state in which the roll diameter on the sheet supply device 102 side is smaller than the roll diameter on the sheet winding device 103 side.

In both FIGS. 6 and 7, (a) schematically shows the sheet supply device 102, the transport means 21, and the sheet winding device 103, and (b) and (c) are the sheets in (a). The internal state of the roll body holding device 30 facing the feeding device 102 and the sheet winding device 103 is illustrated. Note that (b) is a side view of the drive shaft 305 and the driven shaft 314, and (c) is a view of the drive shaft 305 and the driven shaft 314 seen from the axial direction.

FIG. 6 illustrates a state in which the amount of the sheet 120 remaining in the sheet supply device 102 is large in the initial state of the image forming process. FIG. 7 illustrates a state in which the image forming process is advanced and the amount of the sheet 120 remaining in the sheet supply device 102 is small.

First, as shown in FIG. 6A, when the roll diameter on the sheet supply device 102 side is “r1”, the tension generated in the sheet 120 between the transport means 21 and the hollow shaft portion 115 is defined as “F1”. .. Further, at this time, it is assumed that the roll diameter on the sheet winding device 103 side is "r2". Then, the tension generated in the sheet 120 between the transport means 21 and the hollow shaft portion 114 is referred to as "F2".

In the state shown in FIG. 6A, “r1> r2”. In this state, in order to balance the tension generated on the sheet supply device 102 side and the tension generated on the sheet winding device 103 side, that is, in order to make F2 = F1, the driven shaft of the "r1" having a larger roll diameter is used. It is necessary to increase the torque of 314. That is, it is necessary to make the torque applied to the driven shaft 314 of the seat supply device 102 larger than the torque applied to the driven shaft 314 of the sheet winding device 103.

Therefore, as illustrated in FIG. 6B, the drive shaft 305 on the seat supply device 102 side is rotated greatly, and the tensioner 308 on the drive shaft 305 side is formed relative to the tensioner 308 on the driven shaft 314 side. The rotation angle difference Δθ is increased (Δθ1), and this rotation angle difference (Δθ1) is maintained. At this time, a position hold is applied to the motor 301 which is the drive source of the drive shaft 305, and the motor 301 is finely driven so that the relative rotation angle difference (Δθ1) between the drive side and the driven side is maintained.

As described above, if the rotation angle difference Δθ of the tensioner 308 is increased, the force applied to the driven shaft 314 by the spring 309 becomes stronger, and as a result, the tension F1 equivalent to the tension F2 generated on the sheet winding device 103 side is increased. Can be generated on the sheet supply device 102 side. That is, the rotation angle is increased so as to increase the force (torque) to rotate in the direction opposite to the rotation direction following the transport direction of the sheet 120 according to the size of the remaining amount (roll diameter) of the roll body 112. The rotation of the motor 301 is controlled so as to rotate the drive shaft 305 in the direction of increasing the difference (Δθ). Then, when a predetermined rotation angle difference (Δθ) is formed, the rotation of the motor 301 is stopped. In this way, when it is necessary to increase the torque according to the size of the remaining amount (roll diameter) of the roll body 112, it is necessary to maintain F2 = F1 as described above depending on the rotation amount of the motor 301. The amount of rotation of the motor 301 is controlled so as to form a rotation angle difference (Δθ1) for generating a large torque.

On the other hand, since the tension F2 on the sheet winding device 103 side may be generated corresponding to a small diameter (r2), the torque applied to the drive shaft 305 on the sheet winding device 103 side may be small. Therefore, as shown in FIG. 6C, in the sheet winding device 103, the drive shaft 305 may be rotated so that the rotation angle difference is Δθ2, which is smaller than Δθ1.

As described above, in order to balance the tension F1 generated in the sheet 120 at the roll diameter (r1) and the tension F2 generated at the sheet 120 at the roll diameter (r2), the sheet 120 is rotated by being conveyed by the conveying means 21. The rotation amount of the drive shaft 305 (rotation amount of the motor 301) is controlled so as to form and maintain a rotation angle difference (Δθ1) relative to the driven shaft 314. As a result, the magnitude of the torque to be rotated in the direction opposite to the rotation direction of the driven shaft 314 may be automatically adjusted, and the torque may be applied to the driven shaft 314.

As described above, the elastic body is formed by the magnitude of the rotation angle difference (Δθ) relatively formed by the two tensioners 308 based on the rotation amount of the drive shaft 305 and the rotation amount of the driven shaft 314. The magnitude of the elastic force (spring force) of the spring 309 can be set to any magnitude. Therefore, the magnitude of the torque applied to the driven shaft 314 can be arbitrarily set according to the amount of rotation of the motor 301.

Then, the rotation amount of the motor 301 is controlled based on the detection result of the drive side encoder sensor 306 and the detection result of the driven side encoder sensor 310, so that the driven side generated torque is steplessly controlled as described above. Can be adjusted. This allows any tension to be generated in the sheet 120. That is, since the tension on the sheet supply device 102 side and the tension on the sheet winding device 103 side can be generated so as to correspond to the respective roll diameters, even if the transport state of the sheet 120 changes, the tension is uniform. Can be given to the sheet 120.

Further, the transfer amount of the sheet 120 can be calculated from the detection result of the driven side encoder sensor 310 provided in each of the sheet supply device 102 and the sheet winding device 103. Therefore, if the initial value of the roll diameter of the roll body 112 is set for the sheet supply device 102 and the sheet winding device 103, the sheet supply device 102 and the sheet winding device 103 are set based on the transport amount of the sheet 120. The roll diameter in each of the above can be calculated. If the diameter of each roll body 112 can be calculated, an arbitrary tension can be applied to the sheet 120 by rotating the motor 301 accordingly. Then, the control unit 320 controls the rotation amount and the rotation direction of the motor 301 so as to maintain the relative angles of the two tensioners so that the set tension is continuously applied.

Therefore, as illustrated in FIG. 7, by transporting the sheet 120, the magnitude relationship between the diameter of the roll body 112 in the sheet supply device 102 and the diameter of the roll body 112 in the sheet winding device 103 is opposite to that in FIG. If so, the rotation of the motor 301 may be controlled so as to generate F1 and F2 accordingly.

In order to make the tension F generated in the conveyed sheet 120 uniform (constant), as shown in the graph illustrated in FIG. 9, the elapsed time from the transferred state of the sheet 120 and the rotation angle correlating with the elapsed time. The data of the difference Δθ may be stored as table data in the storage means provided in the control unit 320, and the rotation amount of the motor 301 may be controlled while referring to the table data.

The magnitude of the torque generated by the rotational angle difference (Δθ) relatively formed by the two tensioners 308 changes according to the amount of elongation of the spring 309, but when the spring 309 is excessively stretched, torque is generated. May not contribute to. Therefore, an upper limit may be set in advance for the rotation amount of the motor 301, and control may be performed so as to form and maintain a rotation angle difference (Δθ) within a range not exceeding the upper limit. A stopper mechanism for limiting the rotation of the tensioner 308 may be provided so as not to exceed a predetermined rotation angle difference (Δθ).

Further, as will be described later, the relative position of the tensioner 308 such that the degree of extension of the spring 309 is the lowest, that is, the position of the two tensioners 308 in which the spring 309 is in the most contracted state is set as the initial position, and the control unit is used. 320 returns the tensioner 308 to the initial position when the apparatus main body 101 starts operation, that is, when the transfer of the sheet 120 starts. The angle difference (relative angle) at the initial position is zero degree.

Further, since the spring 309 will be torn if it is extended too much, the current threshold value of the rotation angle difference Δθ of the tensioner 308 is stored in advance in the storage means provided in the control unit 320, which will be described later, according to the specifications of the spring 309. The control unit 320 may control the amount of rotation of the motor 301 so that the rotation angle difference Δθ does not exceed the threshold value. That is, the control unit 320 may configure the angle difference limiting means.

[Tension adjustment table]
In the storage means of the control unit 320, which will be described later, a data table that defines the correlation between the magnitude of the relative angle of the tensioner 308 and the force (F) received by the transfer roller 23 constituting the transfer means 21 is stored. Then, when setting the rotation amount of the motor 301, the rotation angle difference Δθ is determined with reference to the data table illustrated in FIG. 8 so as to obtain the optimum tension with respect to the seat 120. Then, the rotation amount of the motor 301 may be controlled so as to form the determined rotation angle difference Δθ.

[Tensioning according to the medium]
Further, information about the sheet 120 to be conveyed is set via the operation panel included in the inkjet printer 100, and based on this information, the optimum tension for the sheet 120 is derived, and the motor 301 is applied with the tension. The amount of rotation may be controlled.

Here, the information about the sheet 120 refers to attribute information that causes fluctuations in the force applied to the sheet 120 in the transport means 21, such as the type, thickness, and airtightness of the sheet 120 used for image forming processing. When the thickness of the sheet 120 is thin, it is preferable to apply a smaller tension than the relatively thick sheet 120. Further, in the platen arranged on the downstream side of the transport means 21, a suction force acts on the sheet 120, so that in the case of the sheet 120 having higher airtightness, it is necessary to apply a tension corresponding to the suction force. In this way, the amount of rotation of the motor 301 that generates tension may be controlled based on the information related to the attributes of the seat 120.

[Control configuration]
FIG. 10 is a hardware configuration diagram included in the control unit 320 for controlling the operation of the inkjet printer 100. As shown in FIG. 10, the control unit 320 includes the same configuration as a general information processing device, controls the operation of the entire inkjet printer 100, and also controls the operations of the sheet supply device 102 and the sheet winding device 103.

In the control unit 320, a CPU (Central Processing Unit) 321, a RAM (Random Access Memory) 322, a ROM (Read Only Memory) 323, an HDD (Hard Disk Drive) 324, and an I / F 325 are connected via a bus 329. .. Further, a display unit 326, an operation unit 327, and a dedicated device 328 are connected to the I / F 325.

The CPU 321 is a calculation means and controls the operation of the entire inkjet printer 100. The RAM 322 is a volatile storage medium capable of high-speed reading and writing of information, and is used as a work area when the CPU 321 processes the information. The ROM 323 is a read-only non-volatile storage medium, and stores programs such as firmware. The HDD 324 is an example of a non-volatile storage medium capable of reading and writing information. In the basic program (OS: Operating System) for operating the inkjet printer 100, the operation of the image forming unit 104 in the inkjet printer 100, and the operation of the sheet 120. Various control programs, application programs, etc. for controlling transport operations are stored. Since the control unit 320 may be provided with a non-volatile storage medium, the control unit 320 is not limited to a medium for recording information on a metal to which a magnetic material is added, such as HDD 324.

The I / F 325 connects and controls the bus 329 with various hardware, networks, and the like. The display unit 326 is a visual user interface for the user to confirm the state of the inkjet printer 100 and the setting of the operation mode of the inkjet printer 100, and is realized by a display device such as an LCD (Liquid Crystal Display). The operation unit 327 is a user interface for the user to input settings related to the control operation of the inkjet printer 100.

The dedicated device 328 is hardware for realizing a function of performing a dedicated operation in the inkjet printer 100, and includes, for example, a configuration for realizing an image forming processing function of the image forming unit 104 and a conveying function for conveying the sheet 120. A configuration to be realized and a configuration to realize a tension applying function for applying an appropriate tension to the sheet 120 are included. That is, the dedicated device 328 includes a motor 301, a drive side encoder sensor 306, a driven side encoder sensor 310, and the like.

The control unit 320 is a software control unit that realizes a predetermined function by reading a program stored in a ROM 323, an HDD 324, or the like into a RAM 322 and executing the program by the CPU 321 using each hardware configuration included in the dedicated device 328. To configure.

As described above, by executing the control program in the control unit 320, the rotation amount of the motor 301 is controlled, and the rotation angle difference Δθ is adjusted to a predetermined value. That is, the control unit 320 constitutes the angle difference adjusting means.

It should be noted that the present invention is not limited to each of the above-described embodiments, and various modifications can be made without departing from the technical gist thereof, and the technical concept included in the claims is described. All of the matters are the subject of the present invention. Although the above embodiment shows a suitable example, those skilled in the art can realize various modified examples from the disclosed contents. Such modifications are also included in the technical scope described in the claims.

1: Guide rod 2: Guide stay 5: Carriage 6a, 6b, 6c, 6d: Recording head 8: Main scanning motor 9: Drive pulley 10: Driven pulley 11: Scanning timing belt 12: Carriage encoder sheet 13: Carriage Encoder sensor 14: Linear encoder 15: Stand body 16: 1st guide 17: 2nd guide 18: 1st holding unit 19: 2nd holding unit 21: Conveying means 23: Conveying roller 24: Pressurizing roller 25: Conveying guide member 26: Suction fan 27: Cutter 30: Roll body holding device 60: Ink cartridge 80: Maintenance / recovery mechanism 100: Inkjet printer 101: Device main body 102: Sheet supply device 103: Sheet winding device 104: Image forming unit 112: Roll body 114: Hollow shaft portion 115: Hollow shaft portion 120: Sheet 130: Guide member 131: Paper ejection guide member 300: Tension control unit 301: Motor 302: Motor shaft pulley 303: Tension adjustment timing belt 304: Drive shaft pulley 305: Drive Axis 306: Drive side encoder sensor 307: Drive side encoder sheet 308: Tensioner 309: Spring 310: Driven side encoder sensor 311: Driven side encoder sheet 312: Flange 314: Driven axis 320: Control unit 321: CPU
322: RAM
323: ROM
324: HDD
325: I / F
326: Display unit 327: Operation unit 328: Dedicated device 329: Bus

Japanese Unexamined Patent Publication No. 2019-163116

Claims (11)

The first rotating means that rotates by the driving force of the driving source,
A second rotating means that rotates according to the transport of the object to be transported, which is wound in a roll shape,
A torque generating means for generating torque for decelerating the rotational speed in the second rotating means according to the difference in rotation angle between the second rotating means and the first rotating means.
Equipped with
The torque generating means is
A tension control device for an object to be transported, comprising an elastic connecting means for connecting an elastic body so as to transmit the driving force from the first rotating means to the second rotating means. The elastic connecting means is
The first connecting member that rotates according to the rotation of the first rotating means,
The second connecting member that rotates according to the rotation of the second rotating means,
It has an elastic member that connects the first connecting member and the second connecting member.
The tension control device for an object to be transported according to claim 1. The first connecting member and the second connecting member are plate-shaped members.
The elastic connecting means connects the ends of the plate-shaped members arranged so as to face each other by the elastic member, and the elasticity of the elastic member caused by the difference in the rotation angle between the first connecting member and the second connecting member. The torque is generated by force.
The tension control device for an object to be transported according to claim 2. The elastic member is a spring member.
The tension control device for an object to be transported according to claim 2 or 3. An angle difference detecting means for detecting the difference in rotation angles is provided.
The tension control device for an object to be transported according to any one of claims 1 to 4. The angle difference detecting means includes a first encoder sheet that rotates with the rotation of the first rotary means, a first encoder sensor that detects the operation of the first encoder sheet, and a second rotary means with rotation. It has a second encoder sheet that rotates and a second encoder sensor that detects the operation of the second encoder sheet.
The difference in the rotation angle is detected based on the detection result of the first encoder sensor and the detection result of the second encoder sensor.
The tension control device for an object to be transported according to claim 5. The elastic connecting means so as to constantly generate the tension generated between the sending side and the winding side of the transported object at the start of transporting the transported object even at the time of transporting the transported object. , The operation of the drive source is controlled to rotate the first rotating means in the winding direction of the object to be conveyed.
The tension control device for an object to be transported according to any one of claims 1 to 6. The elastic connecting means has an angle difference limiting means for preventing the difference in rotation angles from exceeding a predetermined threshold value.
The tension control device for an object to be transported according to any one of claims 1 to 7. A medium supply device for supplying the medium, which is arranged upstream in the transport direction from the transport means for transporting the object to be transported as a medium.
It has a medium winding device, which is arranged on the downstream side in the transport direction from the transport means and winds the medium.
The device to be transported is provided with the tension control device for the object to be transported according to any one of claims 1 to 8 in at least one of the medium supply device and the medium winding device. An image forming unit arranged on the downstream side in the transport direction with respect to the transport means and ejecting a liquid to the medium to form an image.
The liquid ejection device according to claim 9, further comprising a medium supply device for supplying the medium to the image forming unit and a medium winding device for winding the medium. An image forming apparatus according to claim 9, wherein the liquid discharging device according to claim 10 is provided with the liquid discharging device according to claim 10.

Images