JP7475640B2 - Printing device and packaging system - Google Patents

Description

The present invention relates to a printing device and a packaging system.

Conventionally, there is known a printing device that uses a printing unit to print on a print target (substrate) that is transported at a constant speed by a transport roller (see, for example, Patent Document 1).

JP 2011-16895 A

One of the objects printed by the printing device is packaging film for packaging an item. Generally, packaging film is obtained by cutting, by a cutting unit, a film that is unwound from a film roll and transported by a transport roller. Information related to the item is printed on the packaging film by a printing unit. Printing by the printing unit is performed on the print area of the transported film before the film is cut by the cutting unit. Here, when the film is cut by the cutting unit, the transport of the film is temporarily stopped. At this time, the transport of the film by the transport roller is not stopped. Therefore, slack may occur in the film between the transport roller and the cutting unit. If slack occurs in the film, the film may lift off the transport roller, the position of the film may shift relative to the transport roller, or the film may flutter. This may reduce the printing accuracy by the printing unit.

One aspect of the present invention aims to provide a printing device and packaging system that can suppress a decrease in printing accuracy.

A printing device according to one aspect of the present invention includes a transport roller that contacts a long piece of film and transports the film downstream of a transport path at a predetermined speed, a printing unit that is movable between a close position close to the film transported by the transport roller and a separate position away from the film and prints on a print area of the film at the close position, and a dancer roller that is located downstream of the transport roller in the film transport path, and when the transport speed of the film downstream of the dancer roller is slower than the transport speed of the film upstream of the dancer roller, the dancer roller moves the film so that it wraps around the transport roller, absorbing slack in the film.

In a printing device according to one aspect of the present invention, when the transport speed of the film downstream of the dancer roller is slower than the transport speed of the film upstream of the dancer roller, the dancer roller moves the film so that the film wraps around the transport roller, absorbing the slack in the film. As a result, in the printing device, even if the transport speed of the film downstream of the dancer roller becomes slower than the transport speed of the film upstream of the dancer roller due to the film being cut, the dancer roller can eliminate the slack. In addition, the dancer roller moves the film so that the film wraps around the transport roller, so that the film can be kept in contact with the transport roller. As a result, in the printing device, when the printing unit prints on the film, the film can be prevented from floating off the transport roller, the film can be misaligned with respect to the transport roller, or the film can be prevented from flapping. Therefore, the printing device can print on a film in an appropriate state. As a result, the printing device can suppress a decrease in printing accuracy.

In one embodiment, the transport roller transports the film continuously at a constant, predetermined speed, and the dancer roller may move the film so that it wraps around the transport roller and move downward under its own weight to absorb slack in the film when the transport speed of the film downstream of the dancer roller becomes relatively slower than the constant, predetermined speed at which the transport roller transports the film. When the transport speed of the film downstream of the dancer roller becomes relatively slower than the constant, predetermined speed at which the transport roller transports the film, the tension in the film decreases, causing the film to lift up on the transport roller. Therefore, in the printing device, when a speed difference occurs, the dancer roller moves downward under its own weight, applying tension to the film, making it possible to print on the film in an appropriate state.

In one embodiment, the dancer roller may cause the film to wrap around the transport roller by changing the angle at which the film exits the transport roller. In this configuration, the film can be wrapped around the transport roller.

In one embodiment, the transport roller has a side that contacts the film, and is positioned so that when the film enters the side of the transport roller, it is inclined upward with respect to the horizontal plane, and when the film exits from the side of the transport roller, it is inclined downward with respect to the horizontal plane. The dancer roller may move the film to change the position where the contact with the side ends when the film exits the transport roller to the downstream side in the rotation direction of the transport roller, thereby increasing the contact area between the transport roller and the film. If the tension of the film decreases due to a temporary stop of transport downstream of the printing device in the film transport path, the transport of the film will depend on the transport roller. In this configuration, the contact area between the transport roller and the film is increased, so that the frictional force of the transport roller acts on the film more strongly, and slippage between the transport roller and the film can be suppressed.

In one embodiment, the side of the transport roller may be formed of an elastic material that generates a frictional force between the transport roller and the film. This configuration can prevent the film from slipping (shifting out of position) relative to the transport roller. This allows the printing device to print on a film that is in an appropriate state, preventing a decrease in printing accuracy.

In one embodiment, the shaft of the dancer roller is supported movably and includes a guide section that guides the shaft in a predetermined direction, and the guide section may guide the shaft so that the dancer roller approaches the transport roller in the horizontal direction when the transport speed of the film downstream of the dancer roller is slower than the transport speed of the film upstream of the dancer roller. In this configuration, by bringing the dancer roller and the transport roller closer together, the angle at which the film advances from the transport roller can be reduced. This allows the printing device to increase the contact area between the transport roller and the film.

In one embodiment, the diameter of the transport roller may be more than twice the diameter of the dancer roller. In this configuration, by using a transport roller with a relatively large diameter, it is possible to ensure a contact area between the transport roller and the film. Also, in the printing device, by using a dancer roller with a relatively small diameter, it is possible to avoid contact between the transport roller and the dancer roller.

In one embodiment, the printing device may include a detection unit that detects marks that are applied at predetermined intervals in the longitudinal direction of the film corresponding to the printing area of the film, and a control unit that, based on the detection result of the detection unit, moves the printing unit to a close position when the printing area of the film passes relative to the printing unit, and moves the printing unit to a separated position when an area of the film other than the printing area passes relative to the printing unit. In this configuration, the printing unit can be brought close to the film when printing in the printing area, and can be separated from the film when not printing. Therefore, the printing device can avoid contact between the printing unit and the film when not printing, thereby avoiding problems such as leaving scratches on the film.

In one embodiment, a measuring unit is provided that measures the number of pulses associated with the rotation of the transport roller, and the measuring unit starts measuring the number of pulses when the detection unit detects the mark, and the control unit may cause the printing unit to start printing when the number of pulses measured by the measuring unit reaches a predetermined number. If a change occurs in the transport speed of the film after the printing unit starts moving to the approaching position, the printing position may shift. In this configuration, the control unit causes the printing unit to start printing when the number of pulses measured by the measuring unit reaches a predetermined number. As a result, in the printing device, even if a change occurs in the transport speed of the film after the printing unit starts moving to the approaching position, printing can be started at an appropriate timing according to the number of pulses, so that the printing position does not shift. Therefore, the printing device can suppress a decrease in printing accuracy.

In one embodiment, the printing unit may have a print head that prints the ink ribbon on the film by thermal transfer, a supply unit that supplies the ink ribbon to the print head, a recovery unit that winds up and recovers the ink ribbon printed by the print head, a drive roller that is provided between the print head and the recovery unit in the ink ribbon transport path and transports the ink ribbon, and a turn roller that is provided between the drive roller and the recovery unit in the transport path and contacts the ink ribbon to maintain a constant angle when the ink ribbon advances from the drive roller. In order to effectively utilize the ink ribbon, the printing unit backfeeds the ink ribbon by a certain amount using the drive roller after printing by the print head. This reduces the distance between the parts used for printing, thereby reducing the consumption of the ink ribbon. Here, the angle of the ink ribbon that contacts the drive roller changes depending on the change in the diameter of the ink ribbon wound in the recovery unit. Therefore, the amount of backfeed may vary depending on the diameter of the ink ribbon wound in the recovery unit. In this configuration, a turn roller is provided that maintains a constant angle when the ink ribbon advances from the drive roller. This allows the printing device to suppress variation in the amount of backfeed, and therefore makes effective use of the ink ribbon.

In one embodiment, the film is cut by a cutting unit of a packaging system that packages an item to become a packaging film for packaging the item, and the dancer roller may absorb slack in the film while moving the film so that the film wraps around the conveying roller when the film is cut by the cutting unit. In this configuration, even if slack occurs in the film because conveyance of the film is temporarily stopped when the film is cut, the dancer roller can eliminate the slack.

A printing device according to one aspect of the present invention is a printing device used in a packaging system in which a long film is cut by a cutting unit and an article is packaged with the cut packaging film, and the printing device includes a conveying roller that is provided upstream of the cutting unit on the film conveying path and contacts the film to convey the film downstream of the conveying path at a predetermined speed, a printing unit that is movable between a close position close to the film conveyed by the conveying roller and a separate position away from the film and prints on the print area of the film at the close position, and a dancer roller that is provided between the conveying roller and the cutting unit on the film conveying path, and that absorbs slack in the film while moving the film so that it wraps around the conveying roller when the film is cut by the cutting unit.

In a printing device according to one aspect of the present invention, when the film is cut by the cutting section, the dancer roller absorbs slack in the film while moving the film so that it wraps around the transport roller. As a result, in the printing device, even if the transport of the film is temporarily stopped when the film is cut and slack occurs in the film, the dancer roller can eliminate the slack. In addition, since the dancer roller moves the film so that it wraps around the transport roller, the film can be maintained in contact with the transport roller. As a result, when the printing section prints on the film, the printing device can prevent the film from floating up from the transport roller, the film from being misaligned with respect to the transport roller, or the film from flapping. Therefore, the printing device can print on a film that is in an appropriate state. As a result, the printing device can suppress a decrease in printing accuracy.

A packaging system according to one aspect of the present invention includes the above-mentioned printing device, a support section that is provided upstream of the printing device on the film transport path and supports a film roll around which the film is wound, a transport section that is provided downstream of the printing device on the film transport path and transports the film and temporarily stops the transport of the film at a predetermined timing, and a cutting section that cuts the film when the transport of the film is temporarily stopped by the transport section.

A packaging system according to one aspect of the present invention is equipped with the above-mentioned printing device. This makes it possible to suppress a decrease in printing accuracy in the packaging system.

According to one aspect of the present invention, printing accuracy can be improved.

FIG. 1 is a diagram showing the configuration of a packaging system. FIG. 2 is a block diagram showing the configuration of the printing device. FIG. 3 is a diagram showing the configuration of a printing apparatus. FIG. 4 is a diagram showing the configuration of the printing unit. FIG. 5 is a diagram showing the operation of the print head. FIG. 6 is a diagram showing the operation of the printing unit. FIG. 7 is a diagram showing a film.

A preferred embodiment of the present invention will be described in detail below with reference to the attached drawings. In the description of the drawings, the same or equivalent elements are given the same reference numerals, and duplicate descriptions will be omitted.

As shown in FIG. 1, the packaging system 1 includes a printing device 3 and a packaging device 5. The packaging system 1 packages items such as food. The packaging system 1 prints on a film F that will be used to package the items, and packages the items in the printed packaging film RF. The packaging system 1 prints on film F supplied from a film roll FR, and packages the items in packaging film RF made by cutting the film F.

A long film F is supplied to the packaging system 1 from a film roll FR. The packaging system 1 includes a support section 9 that supports the film roll FR, a transport section 11 that transports the film F supplied from the film roll FR, and a cutting section 13 that cuts the film F transported by the transport section 11. The film F extends continuously from the film roll FR to the cutting section 13.

The support unit 9 supports the film roll FR so that it can rotate. The support unit 9 is provided upstream of the printing device 3 on the transport path of the film F. The transport unit 11 is provided between the printing device 3 and the cutting unit 13 on the film transport path. The transport unit 11 transports the film F and temporarily stops the transport of the film F at a predetermined timing. The predetermined timing is set so that a fixed amount of the film F is transported. The predetermined timing also corresponds to the timing at which the cutting unit 13 cuts the film F.

The conveying section 11 includes a pair of rollers 11a, 11b. In the conveying section 11, the pair of rollers 11a, 11b sandwich the film F in the vertical direction, and the pair of rollers 11a, 11b rotate to convey the film F. At least one of the pair of rollers 11a, 11b is driven to rotate by a drive section (not shown). The cutting section 13 cuts the film F when the conveying section 11 temporarily stops conveying the film F. The cutting section 13 cuts the film F when the rotation of the pair of rollers 11a, 11b of the conveying section 11 stops. The film F cut by the cutting section 13 becomes the packaging film RF.

In the transport path of the film F, multiple rollers 15, 16, 17, 18, and 19 are provided between the film roll FR and the packaging device 5. The number and positions of the rollers 15, 16, 17, 18, and 19 may be set appropriately.

The printing device 3 prints on the film F. The printing device 3 inspects the contents printed on the film F. The printing device 3 includes a transport roller 20, a printing unit 22, a dancer roller 24, a detection unit 26 (see FIG. 2), a control unit 28, and a camera 30.

The transport roller 20 transports the film F unwound from the film roll FR. The transport roller 20 is disposed downstream of the film roll FR. The transport roller 20 is provided upstream of the cutting section 13 on the transport path of the film F. The transport roller 20 is positioned below the film F and can contact the underside of the film F. The transport roller 20 contacts the film F and transports the film F toward the downstream side of the transport path at a predetermined speed. The transport roller 20 transports the film F continuously at a constant predetermined speed.

As shown in FIG. 3, the transport roller 20 is rotatably supported by the housing 3A of the printing device 3. The shaft 20a of the transport roller 20 is rotatably supported by the housing 3A. The transport roller 20 rotates by being driven by the transport roller drive unit 21 (see FIG. 2). The operation of the transport roller drive unit 21 is controlled by the control unit 28.

The transport roller 20 has a side (circumferential surface) 20s that comes into contact with the film F. The side 20s is made of an elastic material that generates a frictional force between the film F and the side 20s. The side 20s is made of, for example, rubber. The transport roller 20 is positioned so that when the film F enters the side 20s of the transport roller 20, the transport roller 20 is inclined upward with respect to the horizontal plane, and when the film F exits the side 20s of the transport roller 20, the transport roller 20 is inclined downward with respect to the horizontal plane. The diameter of the transport roller 20 is at least twice the diameter of the dancer roller 24.

The conveying roller 20 is provided with an encoder (measurement unit) 32 (see FIG. 2). The encoder 32 is, for example, a rotary encoder. The encoder 32 measures the number of pulses associated with the rotation of the conveying roller 20. The encoder 32 outputs a pulse signal corresponding to the displacement caused by the rotation of the conveying roller 20. The encoder 32 outputs the pulse signal to the control unit 28. The encoder 32 starts measuring the number of pulses when a measurement signal is output from the control unit 28.

The printing unit 22 prints the printing area A (see FIG. 7) of the film F. As shown in FIG. 4, the printing unit 22 has a print head 40, a supply unit 42, a collection unit 44, a drive roller 46, and a turn roller 48.

The print head 40 prints the ink ribbon R on the film F by thermal transfer. The print head 40 is held by a holder 50. The holder 50 is fixed (supported) to the housing 22A. The print head 40 is supported by the holder 50 so that it can swing. As shown in FIG. 5, the print head 40 swings to move to a close position P1 and a separated position P2. The print head 40 swings due to the drive of the head drive unit 41 (see FIG. 2). The operation of the head drive unit 41 is controlled by the control unit 28. The print head 40 also prints (thermal transfers) on the film F while it is being transported at a substantially constant speed.

As shown in FIG. 4, the supply unit 42 supplies the ink ribbon R to the print head 40. The supply unit 42 rotatably supports the ink ribbon roll RR. The supply unit 42 is provided in the housing unit 22A. The recovery unit 44 winds up and recovers the ink ribbon R used by the print head 40. The recovery unit 44 supports a reel (not shown) that winds up the ink ribbon R. The recovery unit 44 recovers the ink ribbon R by rotating the reel. The recovery unit 44 is provided in the housing unit 22A.

The drive roller 46 transports the ink ribbon R. The drive roller 46 is provided between the print head 40 and the recovery unit 44 in the transport path of the ink ribbon R. The drive roller 46 is provided on the holder 50. The drive roller 46 rotates by being driven by the drive roller drive unit 47. The operation of the drive roller drive unit 47 is controlled by the control unit 28.

The turn roller 48 is provided between the drive roller 46 and the recovery section 44 in the transport path of the ink ribbon R. The turn roller 48 is provided in the housing section 22A. The turn roller 48 contacts the ink ribbon R to maintain a constant angle when the ink ribbon R advances from the drive roller 46. As shown in FIG. 4, the diameter of the ink ribbon R recovered in the recovery section 44 changes depending on the amount of ink ribbon R recovered, as shown by the dashed and solid lines. The turn roller 48 contacts the ink ribbon R between the drive roller 46 and the recovery section 44, thereby maintaining a constant angle when the ink ribbon R advances from the drive roller 46. In other words, the angle of the ink ribbon R located between the drive roller 46 and the turn roller 48 does not change.

As shown in FIG. 6, the housing unit 22A is provided so as to be movable in the extension direction of the transport roller 20. The housing unit 22A is suspended from a rail 54 by an attachment portion 52. The attachment portion 52 is provided so as to be slidable on the rail 54. The rail 54 extends along the extension direction of the transport roller 20. One end of the rail 54 protrudes beyond the end of the transport roller 20. The housing unit 22A is moved along the rail 54 to a position away from above the transport roller 20. This makes it easy to perform maintenance of the printing unit 22 (such as replacing the ink ribbon R).

As shown in FIG. 1, the dancer roller 24 is provided between the transport roller 20 and the cutting section 13 in the transport path of the film F. The dancer roller 24 is located above the transported film F and can contact the upper surface of the film F.

As shown in FIG. 3, the dancer roller 24 is rotatably supported by the housing 3A. The shaft 24a of the dancer roller 24 is rotatably supported by the housing 3A. The shaft 24a is located in a guide groove (guide portion) 29 of the housing 3A. The guide groove 29 movably supports the shaft 24a of the dancer roller 24 and guides the shaft 24a along a predetermined direction. The guide groove 29 is provided in the housing 3A. The guide groove 29 is a hole that penetrates the housing 3A in the thickness direction and extends along one direction. The extension direction of the guide groove 29 is inclined with respect to the horizontal plane. Specifically, the guide groove 29 is inclined in the horizontal direction so that its upper end is farther away from the conveying roller 20 than its lower end.

The shaft portion 24a of the dancer roller 24 is movable within the guide groove 29. The guide groove 29 guides the shaft portion 24a so that the dancer roller 24 approaches the conveying roller 20 in the horizontal direction when the film F is cut by the cutting section 13. When the dancer roller 24 is located at the upper end of the guide groove 29, it is furthest away from the conveying roller 20 in the horizontal direction, and when the dancer roller 24 is located at the lower end of the guide groove 29, it is closest to the conveying roller 20 in the horizontal direction.

When the conveying speed of the film F located downstream of the dancer roller 24 is slower than the conveying speed of the film F located upstream of the dancer roller 24, the dancer roller 24 absorbs the slack of the film F while moving the film F so that the film F wraps around the conveying roller 20. When the film F is cut by the cutting section 13, the conveying speed of the film F located downstream of the dancer roller 24 becomes slower than the conveying speed of the film F located upstream of the dancer roller 24. When the conveying speed of the film F downstream of the dancer roller 24 becomes relatively slow compared to the constant predetermined speed at which the conveying roller 20 conveys the film F, the dancer roller 24 moves downward by its own weight along the guide groove 29 so as to absorb the slack of the film F while moving the film F so that the film F wraps around the conveying roller 20. As a result, the film F does not float up from the conveying roller 20 and continues to be in close contact with the conveying roller 20. Therefore, even if the conveying speed of the film F located downstream of the dancer rollers 24 (i.e., on the cutting section 13 side) becomes slower than the conveying speed of the film F located upstream of the dancer rollers 24 (i.e., on the conveying rollers 20 side), the conveying rollers 20 will continue to convey the film F without slowing it down much.

When the film F is transported with a predetermined tension, the dancer roller 24 is lifted upward by the tension of the film F. For example, as shown in FIG. 3, the dancer roller 24 is located at the first position P11.

When the film F is cut by the cutting section 13, that is, when the transport speed of the film F located downstream of the dancer roller 24 is slower than the transport speed of the film F located upstream of the dancer roller 24, a change occurs in the tension of the film F. Specifically, when the film F is cut by the cutting section 13, transport of the film F is temporarily stopped, so that the tension of the film F decreases. As a result, the dancer roller 24 moves downward by its own weight as the film F slackens, so as to press the film F downward. In this case, as shown in FIG. 3, the dancer roller 24 moves downward along the guide groove 29 and is located at the second position P22. As a result, the dancer roller 24 absorbs the slack of the film F.

The dancer roller 24 winds the film F around the conveying roller 20 by moving along the guide groove 29. The dancer roller 24 winds the film F around the conveying roller 20 by changing the angle at which the film F exits the conveying roller 20. Specifically, the dancer roller 24 moves the film F to change the position at which the film F ends contacting the side surface 20s as it exits the conveying roller 20 to the downstream side in the rotation direction of the conveying roller 20, thereby increasing the contact area between the conveying roller 20 and the film F. For example, as shown in FIG. 5, the dancer roller 24 moves the film F from the position indicated by the solid line to the position indicated by the dashed line. This increases the contact area between the conveying roller 20 and the film F, and the film F winds around the conveying roller 20.

As shown in FIG. 2, the detection unit 26 detects the mark M. The detection unit 26 detects the mark M that is provided at a predetermined interval in the longitudinal direction of the film F corresponding to the print area A of the film F. As shown in FIG. 7, the film F is provided (printed) with the marks M at a predetermined interval in the longitudinal direction (extension direction) D. The detection unit 26 is, for example, a camera. The detection unit 26 is disposed in a position where the mark M can be detected. The detection unit 26 outputs the detection result to the control unit 28.

The control unit 28 controls the operation of the printing device 3. Based on the detection result of the detection unit 26, the control unit 28 moves the printing unit 22 to the approach position P1 when the printing area A of the film F passes by the printing unit 22, and moves the printing unit 22 to the separated position P2 when an area other than the printing area A of the film F passes by the printing unit 22. If the detection result of the detection unit 26 shows that the mark M is detected, the control unit 28 moves the printing unit 22 to the approach position P1. Specifically, the control unit 28 controls the operation of the head drive unit 41 based on the detection result, and controls the printing unit 22.

The control unit 28 causes the printing unit 22 to start printing based on the output result of the encoder 32. When the detection unit 26 detects a mark M, the control unit 28 outputs a measurement signal to the encoder 32 to instruct the encoder 32 to start measurement. The control unit 28 inputs a pulse signal output from the encoder 32 in response to outputting the measurement signal, and when the number of pulses in the pulse signal reaches a predetermined number, causes the printing unit 22 to start printing. The predetermined number is set according to the transport amount of the film F.

The control unit 28 inspects the printing condition based on the image output from the camera 30. The control unit 28 applies image processing to the image and inspects the printing condition (printing position, printed content, etc.). If the control unit 28 detects a defect in the printing condition, it notifies the user of this fact. For example, the control unit 28 causes a display to display this fact.

The camera 30 captures an image of the film F printed by the printing unit 22. For example, the camera 30 captures an image of the print area A of the film F being transported between the rollers 15 and 16. The camera 30 outputs the captured image to the control unit 28.

The camera 30 is provided integrally with the printing unit 22. The camera 30 and the printing unit 22 are connected by a connecting portion 34. Specifically, a bracket 30A that holds the camera 30 and a housing portion 22A of the printing unit 22 are connected by the connecting portion 34. The camera 30 and the printing unit 22 are provided integrally and movable.

As shown in FIG. 1, the packaging device 5 packages an item. The packaging device 5 packages the item with the packaging film RF cut by the cutting unit 13.

Next, the operation of the packaging system 1 will be described. The film F supplied from the film roll FR is transported by the transport rollers 20 at a constant, predetermined speed. The printing unit 22 prints on the film F transported by the transport rollers 20. The camera 30 captures an image of the film F on which printing has been performed by the printing unit 22. The control unit 28 inspects the print condition based on the image captured by the camera 30.

The conveying unit 11 conveys the film F and temporarily stops the conveyance of the film F at a predetermined timing. The cutting unit 13 cuts the film F at the timing when the conveyance of the film F is temporarily stopped. This creates a packaging film RF for packaging an item. The packaging device 5 uses the packaging film RF to package an item.

In the printing device 3, when the conveying speed of the film F changes as a result of the conveying unit 11 temporarily stopping the conveyance of the film F in order to cut the film F by the cutting unit 13, that is, when a difference occurs between the conveying speed of the film F when the film F is cut by the cutting unit 13 and the predetermined speed at which the conveying roller 20 conveys the film F, the dancer roller 24 moves. As the tension generated in the film F decreases (slack in the film F), the dancer roller 24 moves downward along the guide groove 29 and approaches the conveying roller 20. As a result, the film F pressed downward by the dancer roller 24 absorbs the slack (tension is applied by the dancer roller 24) and wraps around the conveying roller 20. As the film F wraps around the conveying roller 20, the contact area between the conveying roller 20 and the film F increases.

As described above, in the printing device 3 of the packaging system 1 according to this embodiment, when the conveying speed of the film F located downstream of the dancer roller 24 is slower than the conveying speed of the film F located upstream of the dancer roller 24, the dancer roller 24 absorbs the slack in the film F while moving the film F so that it wraps around the conveying roller 20. As a result, in the printing device 3, even if the conveying speed of the film F located downstream of the dancer roller 24 becomes slower than the conveying speed of the film F located upstream of the dancer roller 24 by temporarily stopping the conveying of the film F when the film F is cut, causing slack in the film F, the dancer roller 24 can eliminate the slack. In addition, the dancer roller 24 moves the film F so that it wraps around the conveying roller 20, so that the film F can be maintained in contact with the conveying roller 20. As a result, when the printing unit 22 prints on the film F, the printing device 3 can prevent the film F from floating up from the transport roller 20, the position of the film F from shifting relative to the transport roller 20, and fluttering of the film F. Therefore, the printing device 3 can print on the film F in an appropriate state. As a result, the printing device 3 can suppress a decrease in printing accuracy.

The print head 40 prints on the film F by bringing the ink ribbon R, which is fed at approximately the same speed as the transport speed of the film F, into contact with the film F as the film F is transported. Therefore, if the film F at the printing position slows down or stops, the print head 40 cannot print properly. In contrast, in the printing device 3 according to this embodiment, the print head 40 is configured to print (thermal transfer) on the film F being transported at an approximately constant speed, and this can suppress a decrease in printing accuracy. Specifically, even if the transport speed of the film F located downstream of the dancer roller 24 becomes slower than the transport speed of the film F located upstream of the dancer roller 24, the transport roller 20 can continuously transport the film F without causing the film F to slow down. As a result, even if the print head 40 is configured to print (thermal transfer) on the film F being transported at an approximately constant speed, the film F does not stop or slow down during printing, so the printing device 3 of the packaging system 1 according to this embodiment can print with high printing accuracy.

In the printing device 3 according to this embodiment, the conveying roller 20 conveys the film F continuously at a constant predetermined speed. When the conveying speed of the film F downstream of the dancer roller 24 becomes relatively slower than the constant predetermined speed at which the conveying roller 20 conveys the film F, the dancer roller 24 moves the film F so that the film F wraps around the conveying roller 20, and moves downward by its own weight to absorb the slack of the film F. When the conveying speed of the film F downstream of the dancer roller 24 becomes relatively slower than the constant predetermined speed at which the conveying roller 20 conveys the film F, the tension of the film F located downstream of the conveying roller 20 decreases, causing the film F to float up on the conveying roller 20. Therefore, in the printing device 3, when a speed difference occurs, the dancer roller 24 moves downward by its own weight, which applies tension to the film F, making it possible to print on the film F in an appropriate state.

In the printing device 3 according to this embodiment, the dancer roller 24 changes the angle at which the film F advances from the transport roller 20, thereby winding the film F around the transport roller 20. In this configuration, the film F can be wound around the transport roller 20.

In the printing device 3 according to this embodiment, the transport roller 20 has a side surface 20s that contacts the film F, and is disposed at a position where the film F is inclined upward with respect to the horizontal plane when it enters the side surface 20s of the transport roller 20, and is inclined downward with respect to the horizontal plane when it exits from the side surface 20s of the transport roller 20. The dancer roller 24 moves the film F to change the position where the film F ends contacting the side surface 20s when it exits from the transport roller 20 to the downstream side in the rotation direction of the transport roller 20, thereby increasing the contact area between the transport roller 20 and the film F. If the tension of the film F decreases due to a temporary stop of transport downstream of the printing device 3 in the transport path of the film F, the transport of the film F will depend on the transport roller 20. In the printing device 3, the contact area between the transport roller 20 and the film F is increased, so that the frictional force of the transport roller 20 acts more strongly on the film F, and slippage between the transport roller 20 and the film F can be suppressed.

In the printing device 3 according to this embodiment, the side surface 20s of the transport roller 20 is formed of an elastic material that generates a frictional force between the transport roller 20 and the film F. This configuration can prevent the film F from sliding (shifting out of position) relative to the transport roller 20. Therefore, the printing device 3 can print on the film F in an appropriate state, preventing a decrease in printing accuracy.

The printing device 3 according to this embodiment is provided with a guide groove 29 that movably supports the shaft portion 24a of the dancer roller 24 and guides the shaft portion 24a along a predetermined direction. When the transport speed of the film F located downstream of the dancer roller 24 is slower than the transport speed of the film F located upstream of the dancer roller 24, the guide groove 29 guides the shaft portion 24a so that the dancer roller 24 approaches the transport roller 20 in the horizontal direction. In this configuration, by bringing the dancer roller 24 and the transport roller 20 closer to each other, the angle at which the film F advances from the transport roller 20 can be reduced. This allows the printing device 3 to increase the contact area between the transport roller 20 and the film F.

In the printing device 3 according to this embodiment, the diameter of the transport roller 20 is more than twice the diameter of the dancer roller 24. In this configuration, by adopting a transport roller 20 with a relatively large diameter, it is possible to ensure a contact area between the transport roller 20 and the film F. In addition, in the printing device 3, by adopting a dancer roller 24 with a relatively small diameter, it is possible to avoid contact between the transport roller 20 and the dancer roller 24.

The printing device 3 according to this embodiment includes a detection unit 26 that detects marks M that are attached at predetermined intervals in the longitudinal direction of the film F in correspondence with the printing area A of the film F, and a control unit 28 that, based on the detection result of the detection unit 26, moves the printing unit 22 to a close position P1 when the printing area A of the film F passes by the printing unit 22, and moves the printing unit 22 to a separated position P2 when an area other than the printing area A of the film F passes by the printing unit 22. With this configuration, the printing unit 22 can be brought close to the film F when printing in the printing area A, and can be separated from the film F when not printing. Therefore, in the printing device 3, contact between the printing unit 22 and the film F can be avoided when not printing, and the occurrence of defects such as scratches remaining on the film F can be avoided.

The printing device 3 according to this embodiment includes an encoder 32 that measures the number of pulses associated with the rotation of the conveying roller 20. When the mark M is detected by the detection unit 26, the encoder 32 starts measuring the number of pulses. When the number of pulses measured by the encoder 32 reaches a predetermined number, the control unit 28 causes the printing unit 22 to start printing. Here, since the distance between the position of the mark M and the printing position (area to be printed) is determined for each type of (long) film F, if printing is started at the timing when a predetermined number of pulses are generated (i.e., the film F is fed a predetermined distance) after the detection of the mark M by the detection unit 26, printing can be performed according to the printing position. However, the conveying speed of the film F is not always a completely constant speed. Therefore, if the timing is determined and printing is started on the premise that the film F is conveyed at a completely constant speed after the detection of the mark M, the printing position may be shifted if the conveying speed of the film F changes. In addition, the printing unit 22 needs to have moved from the separated position P2 to the close position P1 before starting printing. Therefore, when the detection unit 26 detects the mark M, the control unit 28 starts the movement of the printing unit 22 (head driving unit 41) at a timing when the movement from the approach position P1 to the separation position P2 is completed before the printing position reaches the position of the printing unit 22, even if the transport speed of the film F is always at the theoretical maximum value. As a result, the printing unit 22 is ready to start printing when the film is transported a predetermined amount from the time when the mark M is detected (i.e., the number of pulses becomes a predetermined number) regardless of how the transport speed of the film F changes. Also, in the printing device 3, the control unit 28 causes the printing unit 22 to start printing (thermal transfer) when the number of pulses measured by the encoder 32 becomes a predetermined number. With these configurations, in the printing device 3, even if the transport speed of the film F changes after the printing unit 22 starts moving to the approach position P1, printing can be started at an appropriate timing according to the number of pulses, so the printing position does not shift. Therefore, in the printing device 3, a decrease in printing accuracy can be suppressed.

In the printing device 3 according to this embodiment, the printing section 22 includes a print head 40 that prints the ink ribbon R on the film F by thermal transfer, a supply section 42 that supplies the ink ribbon R to the print head 40, a recovery section 44 that winds up and recovers the ink ribbon R printed by the print head 40, a drive roller 46 that is provided between the print head 40 and the recovery section 44 in the transport path of the ink ribbon R and transports the ink ribbon R, and a turn roller 48 that is provided between the drive roller 46 and the recovery section 44 in the transport path and contacts the ink ribbon R to maintain a constant angle when the ink ribbon R advances from the drive roller 46. In the printing section 22, in order to effectively utilize the ink ribbon R, after printing by the print head 40, the ink ribbon R is back-fed by a certain amount by the drive roller 46. This reduces the distance between the parts used for printing, thereby reducing the consumption of the ink ribbon R. Here, the angle of the ink ribbon R that contacts the drive roller 46 changes due to the change in the diameter of the ink ribbon R wound in the recovery section 44. Therefore, the amount of backfeed may vary depending on the diameter of the ink ribbon R wound around the recovery section 44. The printing section 22 has a turn roller 48 that maintains a constant angle when the ink ribbon R advances from the drive roller 46. This allows the printing device 3 to suppress variation in the amount of backfeed. Therefore, the ink ribbon R can be used effectively.

Although the embodiments of the present invention have been described above, the present invention is not necessarily limited to the above-described embodiments, and various modifications are possible without departing from the spirit of the present invention.

In the above embodiment, an example has been described in which the dancer rollers 24 move along the guide grooves 29 under their own weight. However, the dancer rollers 24 may be driven in response to the tension of the film F. In this case, sensors are provided to detect the film transport speed downstream of the dancer rollers 24 and the film transport speed upstream of the dancer rollers 24, and the dancer rollers 24 are driven based on the detection results of the sensors.

In the above embodiment, an example has been described in which the printing unit 22 prints using an ink ribbon R. However, the printing method is not limited to this, and may be, for example, an inkjet method.

1...packaging system, 3...printing device, 11...conveying section, 13...cutting section, 20...conveying roller, 20s...side, 22...printing section, 24...dancer roller, 24a...shaft section, 26...detecting section, 28...control section, 29...guide groove (guide section), 32...encoder (measurement section), 40...printing head, 42...supply section, 44...recovery section, 46...drive roller, 48...turn roller, A...printing area, F...film, FR...film roll, M...mark, P1...close position, P2...separate position, R...ink ribbon, RF...packaging film.

Claims (13)

a conveying roller that contacts the long film and conveys the film downstream of a conveying path at a predetermined speed;
a printing unit that is movable between a close position where the printing unit is close to the film transported by the transport roller and a separate position where the printing unit is separate from the film, and that prints on a printing area of the film at the close position;
a dancer roller provided downstream of the transport roller in a transport path of the film,
a dancer roller that moves the film so that the film is wound around the conveying roller and absorbs slack in the film when the conveying speed of the film downstream of the dancer roller is slower than the conveying speed of the film upstream of the dancer roller. the transport roller transports the film continuously at the predetermined constant speed;
2. The printing apparatus according to claim 1, wherein, when a conveying speed of the film downstream of the dancer roller becomes slower relative to the predetermined constant speed at which the conveying roller conveys the film, the dancer roller moves the film so that the film is wound around the conveying roller, and moves downward by its own weight so as to absorb slack in the film. The printing device according to claim 1 or 2, wherein the dancer roller causes the film to wrap around the transport roller by changing the angle at which the film advances from the transport roller. the transport roller has a side surface that comes into contact with the film, and is disposed at a position such that when the film enters the side surface of the transport roller, the transport roller is inclined upward with respect to a horizontal plane, and when the film exits the side surface of the transport roller, the transport roller is inclined downward with respect to the horizontal plane,
The printing device according to any one of claims 1 to 3, wherein the dancer roller moves the film to change the position at which the film ends contact with the side surface as it advances from the conveying roller to the downstream side in the rotation direction of the conveying roller, thereby increasing the contact area between the conveying roller and the film. The printing device according to claim 4, wherein the side surface of the transport roller is formed of an elastic material that generates a frictional force between the transport roller and the film. a guide portion that movably supports the shaft portion of the dancer roller and guides the shaft portion along a predetermined direction,
6. The printing device according to claim 1, wherein the guide section guides the shaft section so that the dancer roller approaches the feed roller in the horizontal direction when a feed speed of the film located downstream of the dancer roller is slower than a feed speed of the film located upstream of the dancer roller. The printing device according to any one of claims 1 to 6, wherein the diameter of the transport roller is at least twice the diameter of the dancer roller. a detection unit that detects marks provided at predetermined intervals in a longitudinal direction of the film corresponding to the printing area of the film;
A printing device as described in any one of claims 1 to 7, comprising a control unit that moves the printing unit to the close position when the printing area of the film passes relative to the printing unit, and moves the printing unit to the separated position when an area of the film other than the printing area passes relative to the printing unit, based on the detection result of the detection unit. A measuring unit is provided to measure the number of pulses associated with the rotation of the conveying roller,
the measuring unit starts measuring the number of pulses when the detection unit detects the mark,
The printing device according to claim 8 , wherein the control unit causes the printing unit to start printing when the number of pulses measured by the measurement unit reaches a predetermined number. The printing unit includes:
a print head for printing an ink ribbon onto the film by thermal transfer;
a supply unit that supplies the ink ribbon to the print head;
a recovery unit that winds up and recovers the ink ribbon printed by the print head;
a drive roller that is provided between the print head and the recovery unit in a transport path of the ink ribbon and transports the ink ribbon;
A printing device as described in any one of claims 1 to 9, further comprising: a turn roller that is provided between the drive roller and the recovery section on the transport path, contacts the ink ribbon, and maintains a constant angle when the ink ribbon advances from the drive roller. the film is cut by a cutting unit of a packaging system for packaging an article to become a packaging film for packaging the article;
11. The printing device according to claim 1, wherein the dancer roller absorbs slack in the film while moving the film so that the film is wound around the transport roller when the film is cut by the cutting section. A printing device used in a packaging system that cuts a long film with a cutting unit and packages an article with the cut packaging film,
a conveying roller that is provided upstream of the cutting section in a conveying path of the film and that contacts the film to convey the film downstream of the conveying path at a predetermined speed;
a printing unit that is movable between a close position where the printing unit is close to the film transported by the transport roller and a separate position where the printing unit is separate from the film, and that prints on a printing area of the film at the close position;
a dancer roller provided between the transport roller and the cutting section in a transport path of the film,
the dancer roller moves the film so that the film is wound around the conveying roller when the film is cut by the cutting section, and absorbs slack in the film. A printing device according to any one of claims 1 to 12,
a support unit that is provided upstream of the printing device in a transport path of the film and supports a film roll around which the film is wound;
a transport unit that is provided downstream of the printing device in a transport path of the film, transporting the film and temporarily stopping the transport of the film at a predetermined timing;
a cutting unit that cuts the film when the conveying unit temporarily stops conveying the film.

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