Constant pitch printing system

Abstract

To reliably form a printed part on each of different kinds of packages with different packaging material lengths so that there is no missing printed part when a length along a transportation direction in the state that the packaging material forming the package is expanded is represented by the packaging material length.SOLUTION: When a shortest one of a multiple kinds of packaging material lengths L1 is represented by Lmin and a distance between adjacent printing parts 16 in a transportation direction of a packaging material 10 is represented by a printing pitch ΔP, a printing mechanism 22 is controlled by a control part 32 so that the printing part 16 is formed at a previously registered printing pitch ΔP of a single value satisfying the following formula: 0.5 Lmin<ΔP<Lmin on the basis of a transportation amount detected by a transportation amount detection part 24.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a printing method control system using a printer device.

Background Art

[0002] There is provided a packaging machine that forms a bag body using a long packaging material conveyed from the upstream side to the downstream side, and manufactures a package in which a product such as food is accommodated in the bag body. And, there is provided a printer device that is disposed on the upstream side in the conveyance direction of the packaging material of such a packaging machine and includes a printing mechanism that forms printing portions such as an expiration date (consumption deadline) and a manufacturing number on the packaging material (see Patent Document 1). Normally, registration marks (eye marks) corresponding to each package are formed on the packaging material at regular intervals in the conveyance direction, and the printer device controls the printing mechanism based on a detection signal generated from a detection unit that detects the registration marks to form one printing portion for each package. In addition, there may be a case where a packaging material on which no registration mark is formed is used. In that case, the packaging machine generates a predetermined printing signal for each package and supplies it to the printer device, and the printer device controls the printing mechanism based on the printing signal to form one printing portion for each package.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the above-described packaging machine, when the length along the conveyance direction in the state where the packaging material forming the package was unfolded was defined as the packaging material length, the packaging machine manufactured the same single type of package having the same packaging material length. However, in recent years, in response to variations in the size (individual differences) of products packaged in packaging materials or variations in the spacing between adjacent products when multiple products are packaged in a package, users of packaging machines have demanded the production of multiple types of packages with different sizes (different lengths along the conveying direction). That is, as a package for accommodating one product, it is required to produce multiple types of packages with different lengths along the conveying direction of the packaging material, or as a package for packaging N (N is a natural number of 2 or more) products, it is required to produce multiple types of packages with different lengths along the conveying direction of the packaging material. However, since it is not possible to provide registration marks at regular intervals on the packaging materials used in such packaging machines, the printer device arranged upstream of the packaging machine is required to have a function of surely forming a printing portion without omission of the printing portion for each of multiple types of packages with different packaging material lengths without using registration marks. Alternatively, even in the case of a printer device that operates based on a printing signal supplied from a packaging machine without using registration marks, when the packaging machine is designed to produce packages with different sizes (different lengths along the conveying direction) for the above reasons, it becomes difficult to supply the printing signal from the packaging machine to the printer device at an appropriate timing. Therefore, similarly to the above, a function of surely forming a printing portion without omission of the printing portion for each of multiple types of packages with different packaging material lengths is required. The present invention has been devised in view of the above circumstances. The object of the present invention is to provide a printer device that is advantageous in surely forming a printing portion without omission of the printing portion for each of those packages when the specification of the packaging machine is to produce multiple types of packages with different packaging material lengths.

Means for Solving the Problems

[0005] To achieve the above object, an embodiment of the present invention is a printer device disposed upstream in the conveying direction of a packaging material of a packaging machine that manufactures a package in which a product is contained by a long packaging material conveyed from an upstream side to a downstream side and includes a printing mechanism that forms a printing portion while conveying the packaging material. The packaging machine manufactures a plurality of types of the packages having different lengths along the conveying direction while conveying the packaging material. A conveyance amount detection unit is provided for detecting the conveyance amount of the packaging material passing through the printing mechanism. The length along the conveying direction in a state where the packaging material for forming each of the plurality of types of the packages is unfolded is defined as a packaging material length L1, the shortest one among the plurality of types of the packaging material lengths L1 is defined as a minimum packaging material length Lmin, and when the interval between the printing portions adjacent to each other in the conveying direction of the packaging material is defined as a printing pitch ΔP, the printing mechanism is controlled to form the printing portion with the printing pitch ΔP which is a single registered value satisfying the following formula (1) based on the conveyance amount detected by the conveyance amount detection unit. 0.5Lmin < ΔP < Lmin Formula (1) Further, in an embodiment of the present invention, the packaging machine manufactures the package using the packaging material pulled out from and conveyed by the printer device. The printer device includes a start signal generation unit that detects that the conveyance of the packaging material by the packaging machine has started and generates a start signal. The control unit controls the printing mechanism based on the start signal. Further, in an embodiment of the present invention, a buffer unit capable of absorbing slack of the packaging material is provided on the downstream side of the printing mechanism. Further, in an embodiment of the present invention, when the longest one among the plurality of types of packaging material lengths L1 is defined as a maximum packaging material length Lmax, the maximum value of the absorption amount of the slack of the packaging material by the buffer unit is equal to or greater than the maximum packaging material length Lmax. A maximum value detection unit is provided for detecting that the absorption amount of the slack by the buffer unit has reached the maximum value. The control unit stops the operation of the printing mechanism when the maximum value is detected by the maximum value detection unit. Further, in one embodiment of the present invention, the printing mechanism includes a print head, a printing roller that can rotate while sandwiching the packaging material between the print head, and a driving unit that rotationally drives the printing roller to convey the packaging material. The conveyance amount detection unit includes a first encoder that outputs a first detection signal corresponding to the rotation amount of the printing roller, and the detection of the conveyance amount of the packaging material by the conveyance amount detection unit is based on the first detection signal. Also, in one embodiment of the present invention, the driving unit includes a driving motor and a rotational driving force transmission unit that transmits the rotational driving force of the driving motor to the printing roller. The rotational driving force transmission unit disconnects the driving motor from the printing roller and stops the transmission of the rotational driving force of the driving motor to the printing roller when the rotational speed of the printing roller becomes higher than a predetermined rotational speed. Furthermore, in one embodiment of the present invention, the printing mechanism includes a conveyance speed detection unit that detects the conveyance speed of the packaging material wound around the printing roller, and the control of the printing mechanism by the control unit is based on the conveyance speed of the packaging material detected by the conveyance speed detection unit. Further, an embodiment of the present invention is a printer device disposed upstream in the conveying direction of a packaging machine that manufactures a package in which a product is accommodated by a long packaging material conveyed from upstream to downstream and includes a printing mechanism that forms a printing portion while conveying the packaging material. The packaging machine manufactures a plurality of types of single packages having different lengths along the conveying direction while conveying the packaging material, or a plurality of types of continuous packages having different lengths along the conveying direction formed by connecting N (N is a natural number of 2 or more) of the single packages in the conveying direction. A conveyance amount detection unit for detecting the conveyance amount of the packaging material passing through the printing mechanism is provided. When the length along the conveying direction in a state where the packaging material forming the single package is unfolded is defined as the individual packaging material length Lp, and the interval between the printing portions adjacent to each other in the conveying direction of the packaging material is defined as the printing pitch ΔP, a control unit is provided to control the printing mechanism to form the printing portion with the printing pitch ΔP of a single registered value that satisfies the following formula (2) based on the conveyance amount detected by the conveyance amount detection unit. 0.5Lp < ΔP < Lp Formula (2)

Effect of the Invention

[0006] According to an embodiment of the present invention, when the shortest of the plurality of types of packaging material lengths L1 is defined as the minimum packaging material length Lmin, and the interval between the printing portions adjacent to each other in the conveying direction of the packaging material is defined as the printing pitch ΔP, the control unit controls the printing mechanism to form the printing portion with the printing pitch ΔP of a single registered value that satisfies the following formula (1) based on the conveyance amount detected by the conveyance amount detection unit. 0.5Lmin < ΔP < Lmin Formula (1) Therefore, even when no registration mark is formed on the packaging material, or even when a predetermined printing signal is not supplied to the printer device for each package from the packaging machine, it is advantageous for the printer device to surely form the printing portion so that there is no omission of the printing portion for each of the plurality of types of packages having different packaging material lengths L1. Further, according to an embodiment of the present invention, the packaging machine manufactures the package using the packaging material pulled out from the printer device and conveyed, and the control unit controls the printing mechanism based on the activation signal generated by detecting that the conveyance of the packaging material by the packaging machine has started. Therefore, even when the packaging machine does not have a function of supplying a control signal (printing signal) for instructing the timing for forming the printing unit to the printer device at an appropriate position, it is advantageous for reliably forming the printing unit so that there is no omission of the printing unit for each of a plurality of types of packages having different packaging material lengths L1. Further, according to an embodiment of the present invention, since a buffer unit capable of absorbing the slack of the packaging material is provided on the downstream side of the printing mechanism, the slack of the packaging material generated when the packaging machine intermittently or continuously manufactures the package can be absorbed by the buffer unit. Also, since the slack of the packaging material generated due to the indefinite conveyance speed of the packaging material can be absorbed by the buffer unit, it is advantageous for smoothly and reliably forming the printing unit by the printer device. Further, according to an embodiment of the present invention, the maximum value of the amount of slack of the packaging material absorbed by the buffer unit is equal to or greater than the maximum packaging material length Lmax, and it includes a maximum value detection unit for detecting that the amount of slack absorbed by the buffer unit has reached the maximum value. The control unit stops the operation of the printing mechanism when the maximum value is detected by the maximum value detection unit. Therefore, there is no occurrence of slack of the packaging material that cannot be absorbed by the buffer unit, which is more advantageous for smoothly and reliably forming the printing unit by the printer device. Further, according to an embodiment of the present invention, since the conveyance amount detection unit can reliably detect the conveyance amount of the packaging material passing through the printing mechanism, it is more advantageous for smoothly and reliably forming the printing unit by the printer device. Further, according to an embodiment of the present invention, the control of the printing mechanism by the control unit is performed based on the conveyance speed of the packaging material detected by the conveyance speed detection unit. Therefore, the printing unit is accurately printed without being affected by the variation in the conveyance speed of the packaging material, which is advantageous for improving the quality of the printing unit. Further, according to an embodiment of the present invention, when the rotational speed of the impression roller becomes higher than a predetermined rotational speed, the rotation drive force transmission unit disconnects the drive motor from the impression roller and stops the transmission of the rotational drive force of the drive motor to the impression roller. Therefore, even when the packaging machine continuously pulls out and conveys the packaging material from the printer device and continuously manufactures the packages, it is possible to form the printing portion at a pre-registered printing pitch ΔP. Even when the packaging machine intermittently manufactures the packages, it is advantageous for smoothly and surely forming the printing portion by the printer device, and is advantageous for improving the convenience of the printer device. Further, according to an embodiment of the present invention, the length along the conveyance direction in the state where the packaging material for forming a single package is developed is defined as the individual packaging material length Lp, the interval between adjacent printing portions in the conveyance direction of the packaging material is defined as the printing pitch ΔP, and the control unit controls the printing mechanism to form the printing portion at a pre-registered single value of the printing pitch ΔP that satisfies the following formula (2) based on the conveyance amount detected by the conveyance amount detection unit. 0.5Lp < ΔP < Lp Formula (2) Therefore, even when no registration mark is formed on the packaging material, and even when no predetermined printing signal is supplied to the printer device for each unit package or for each continuous package from the packaging machine, for a plurality of types of single packages having different lengths along the conveyance direction of the packaging material, or for each of the single packages constituting a plurality of types of continuous packages having different lengths along the conveyance direction of the packaging material, it is advantageous for surely forming the printing portion so that there is no omission of the printing portion.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

Embodiments for Carrying Out the Invention

[0008] (First Embodiment) Hereinafter, the first embodiment will be described with reference to the drawings. Before describing the printer device (fixed pitch printing system) of the embodiment, the packaging material and the packaging machine will be described. As shown in FIG. 2(A) and the like, the packaging material 10 is for packaging products such as food, and is composed of a long and uniform-width packaging film. As the packaging film, a film made of a transparent or opaque synthetic resin material, a light-shielding aluminum vapor-deposited film, etc. are used, but the type of the film is not limited. No registration marks are formed on the packaging material 10. Also, as will be described later, since the packaging machine manufactures a plurality of types of packages using a plurality of types of packaging materials 10 having different packaging material lengths, no designs such as characters and patterns corresponding to the products are formed on the packaging material 10. Therefore, the packaging material 10 is plain, transparent, or has only a uniform pattern.

[0009] As shown in FIG. 1(A), the packaging machine 12 manufactures a package containing a product using the packaging material 10 pulled out from and conveyed by the printer device 14. Examples of the packaging machine 12 include a horizontal pillow packaging machine and a vertical pillow packaging machine. The horizontal pillow packaging machine shapes the packaging material 10 conveyed from the upstream side to the downstream side on the horizontal plane into a cylindrical shape to accommodate the product, heat-seals the edges of the cylindrical packaging material 10 to form a center seal, and then heat-seals the front and rear in the conveyance direction of the packaging material 10 with respect to the product to form an end seal. After that, the end seal part is cut to manufacture the package. The vertical pillow packaging machine forms the packaging material 10 conveyed from the upstream side to the downstream side into a cylindrical shape, conveys the cylindrical packaging material 10 vertically downward, heat-seals the edges of the cylindrical packaging material 10 to form a center seal, and heat-seals the edges of the cylindrical packaging material 10 to form an end seal to form the bottom of the bag. Then, the product to be packaged is put into or filled into the cylindrical packaging material 10, and after heat-sealing the portion corresponding to the bag mouth to form an end seal, the end seal portion is cut to manufacture the package. The printer device 14 of the present embodiment can be widely applied not only to the above-described horizontal pillow packaging machine and vertical pillow packaging machine, but also to packaging machines that use a long packaging material 10 to package products and manufacture packages. Here, as shown in FIG. 2(A), when the length along the conveyance direction in the state where the packaging materials 10 for forming a plurality of types of packages are developed is defined as the packaging material length L1, the packaging machine 12 to which the printer device 14 of the present embodiment is applied manufactures a plurality of types of packages having different packaging material lengths L1. Note that, as in the prior art, the packaging machine 12 does not have a function of supplying a control signal (printing signal) for instructing the timing for forming the printing unit 16 (see FIG. 2(A)) at an appropriate position of the packaging material 10 to the printer device 14.

[0010] Next, the printer device 14 of the present embodiment will be described. In the present embodiment, the case where the printer device 14 is a thermal printer device will be described. However, the present invention is not limited to a thermal printer device, and the printer device 14 can be widely applied to various conventionally known printer devices such as a hot roller printer device, an inkjet printer device, and a laser marker device. Further, the printer device 14 of the present invention is not limited to directly printing on the packaging material 10, and can of course be applied to a labeling machine that prints on a label and then attaches the printed label to the packaging material 10. As shown in Fig. 1(A), the packaging material 10 drawn from the original web 11 is first wound around and guided by a plurality of guide rollers G1, G2, and G3 provided in the packaging machine 12, and then introduced into the printer device 14. After being wound around and guided by a plurality of guide rollers G4, G5, G6, and G7 of the packaging machine 12 from the printer device 14, it is conveyed into the interior of the packaging machine 12. Then, the packaging machine 12 uses the packaging material 10 to package the product and manufactures the package. That is, the printer device 14 is disposed upstream in the conveyance direction of the packaging material 10 of the packaging machine 12.

[0011] The packaging machine 12 is provided with a packaging machine side conveyance unit 18 for conveying the packaging material 10. The packaging machine side conveyance unit 18 includes a pair of conveyance rollers 1802 and 1804 and a first drive motor 1806. The pair of conveyance rollers 1802 and 1804 is composed of a drive roller 1802 that is rotationally driven by the first drive motor 1806 and a driven roller 1804 that sandwiches the packaging material 10 between the drive roller 1802. The rotation control of the first drive motor 1806 is performed independently of the printer device 14 by a control unit (not shown) of the packaging machine 12. When the first drive motor 1806 rotates, the packaging material 10 is conveyed from the upstream side to the downstream side in the conveyance direction by the pair of conveyance rollers 1802 and 1804. In the present embodiment, a case will be described where the packaging machine 12 intermittently executes the manufacture of the package while repeating the operation of pulling out and conveying the packaging material 10 from the printer device 14 and the operation of stopping the conveyance by controlling the first drive motor 1806.

[0012] The printer device 14 includes a plurality of guide rollers, a start signal generation unit 20, a printing mechanism 22, a conveyance amount detection unit 24, a conveyance speed detection unit 26, a buffer unit 28, a maximum value detection unit 30, and a control unit 32.

[0013] The start signal generation unit 20 detects that the conveyance of the packaging material 10 by the packaging machine 12 has started, generates a start signal, and supplies it to the control unit 32. In this embodiment, the start signal generation unit 20 is constituted by a start signal encoder 2002 that is provided on the driven roller 1804 of the packaging machine side conveyance unit 18 and outputs a detection signal (pulse signal) corresponding to the rotation amount of the driven roller 1804. That is, when no detection signal is output from the start signal encoder 2002, the conveyance of the packaging material 10 is stopped, and when a detection signal is output, it indicates that the conveyance of the packaging material 10 is being executed. Therefore, the detection signal of the start signal encoder 2002 serves as the above-mentioned start signal.

[0014] The printing mechanism 22 forms a printing unit 16 while conveying the long packaging material 10 that is conveyed from the upstream side to the downstream side. The printing mechanism 22 includes a housing 34, a print head (when the printer device 14 is a thermal printer device, a thermal head) 36, an ink ribbon conveyance mechanism (not shown), a printing receiving roller 38, and a drive unit 40. The packaging material 10 drawn out from the plurality of guide rollers G1, G2, G3 of the packaging machine 12 is introduced into the printing mechanism 22 via the guide rollers G8, G9. The housing 34 is a part that houses the print head 36 and the ink ribbon conveyance mechanism that constitute a part of the printing mechanism 22, and is disposed above the conveyed packaging material 10. The print head 36 is disposed to face the printing receiving roller 38 with the ribbon of the ribbon conveyance mechanism and the packaging material 10 interposed therebetween. The print head 36 is provided with a plurality of heating elements at its tip. By selectively energizing these plurality of heating elements, heat is generated, and the ink of the ink ribbon that comes into contact with the heated heating elements adheres to the packaging material 10, thereby forming the printing unit 16 on the packaging material 10.

[0015] Although the ribbon conveyance mechanisms are not shown, they convey the unused ink ribbon drawn out from the raw material side ribbon holder toward the print head 36 and wind up the used ink ribbon on the winding side ribbon holder.

[0016] The printing receiving roller 38 is configured to be rotatable while sandwiching the packaging material 10 between it and the guide roller G9, and also while sandwiching the packaging material 10 between it and the print head 36. Specifically, it is configured to be rotatable while winding a part of the packaging material 10 around its circumferential surface with the packaging material 10 disposed between it and the print head 36. As shown in FIG. 1(B), the printing receiving roller 38 includes a roller body 3802 formed of silicone rubber, and a rotating shaft 3804 that penetrates the center of the roller body 3802 and is integrally provided with the roller body 3802, protruding from both axial ends of the roller body 3802 and rotatably supported via a bearing (not shown).

[0017] As shown in FIG. 1(B), the drive unit 40 rotates the printing receiving roller 38 to convey the packaging material 10. In the present embodiment, the drive unit 40 includes a drive motor 42 and a power transmission mechanism 44. The drive motor 42 transmits a rotational driving force to the rotating shaft 3804 of the printing receiving roller 38 via the power transmission mechanism 44. The power transmission mechanism 44 includes a drive pulley 4402 provided on the drive shaft of the drive motor 42, a driven pulley 4404 provided on the rotating shaft 3804 of the printing receiving roller 38, and a belt 4406 wound around the drive pulley 4402 and the driven pulley 4404. In the present embodiment, the driven pulley 4404 includes a one-way clutch 46 that transmits the rotational driving force of the drive motor 42 to the printing receiving roller 38 and idles when the rotational speed of the printing receiving roller 38 becomes higher than a predetermined rotational speed. Here, the predetermined rotational speed is a value higher than the rotational speed of the printing receiving roller 38 when the packaging machine 12 intermittently manufactures the package as described later. In other words, this one-way clutch 46 constitutes a rotational driving force transmission unit that transmits the rotational driving force of the drive motor 42 to the impression receiving roller 38. When the rotational speed of the impression receiving roller 38 becomes higher than a predetermined rotational speed, this rotational driving force transmission unit disconnects the drive motor 42 from the impression receiving roller 38 and stops the transmission of the rotational driving force of the drive motor 42 to the impression receiving roller 38. In the present embodiment, a one-way clutch 46 is used as the rotational driving force transmission unit. However, as long as the rotational driving force transmission unit can transmit the rotational driving force of the drive motor 42 to the impression receiving roller 38 and disconnect the drive motor 42 from the impression receiving roller 38 when the rotational speed of the impression receiving roller 38 becomes higher than a predetermined rotational speed, various conventionally known clutches such as an electromagnetic clutch can be used.

[0018] The conveyance amount detection unit 24 detects the conveyance amount of the packaging material 10 passing through the printing mechanism 22. As shown in FIG. 1(B), the conveyance amount detection unit 24 includes a first encoder 2402 provided on the rotation shaft 3804 of the impression receiving roller 38, which outputs a first detection signal corresponding to the rotation amount of the impression receiving roller 38 and supplies it to the control unit 32. Therefore, even when the impression receiving roller 38 rotates because the one-way clutch 46 transmits the rotational driving force of the drive motor 42 to the impression receiving roller 38, or when the impression receiving roller 38 rotates in a state where the one-way clutch 46 idles and does not transmit the rotational driving force of the drive motor 42 to the impression receiving roller 38, the first encoder 2402 outputs a first detection signal. Therefore, the detection of the conveyance amount of the packaging material 10 by the conveyance amount detection unit 24 is performed based on the first detection signal.

[0019] The conveyance speed detection unit 26 detects the conveyance speed of the packaging material 10 wound around the impression receiving roller 38. In other words, it detects the conveyance speed of the packaging material 10 passing through the tip of the print head 36. The conveying speed detection unit 26 includes a driven roller 2602 that can rotate while sandwiching the packaging material 10 between it and the printing receiving roller 38, a second encoder 2604 that outputs a second detection signal corresponding to the rotation amount of the driven roller 2602, and a conveying speed calculation unit 33 that calculates the conveying speed of the packaging material 10 based on the second detection signal. The conveying speed calculation unit 33 can be arbitrarily configured by a computer, similar to the control unit 32. Therefore, the detection of the conveying speed of the packaging material 10 by the conveying speed detection unit 26 is performed based on the second detection signal.

[0020] The buffer unit 28 is provided on the downstream side of the printing mechanism 22 in the conveying direction of the packaging material 10 and is configured to be able to absorb the slack of the packaging material 10. In the present embodiment, the packaging material 10 guided by the guide rollers G10 and G11 arranged on the downstream side of the printing receiving roller 38 in the conveying direction is introduced into the buffer unit 28, and the packaging material 10 pulled out from the buffer unit 28 is guided by the guide rollers G12 and G13 and then introduced into the packaging machine side conveying unit 18 through the guide rollers G4, G5, G6, and G7 provided on the packaging machine 12.

[0021] The buffer unit 28 includes a slide rail 48, a movable table 50, a first movable roller 52, a fixed roller 54, and a second movable roller 56. The slide rail 48 extends linearly with an inclination that gradually displaces upward as it reaches one end in the longitudinal direction. The movable table 50 is supported by the slide rail 48 so as to be linearly reciprocally movable. The movable table 50 is regulated in its upper limit position and lower limit position by abutting against the upper limit stopper 58A and the lower limit stopper 58B provided at both ends of the slide rail 48. The first movable roller 52 and the second movable roller 56 are rotatably supported on the movable table 50 with a space therebetween. The fixed roller 54 is provided near the upper end of the slide rail 48 and is rotatably provided with its axis parallel to the axes of the first movable roller 52 and the second movable roller 56.

[0022] The packaging material 10 drawn from the guide roller G11 is wound around the first movable roller 52, the fixed roller 54, and the second movable roller 56 in this order, and then wound around the guide roller G12. Therefore, when the movable table 50 is located at the upper limit position, the fixed roller 54, the first movable roller 52, and the second movable roller 56 are closest to each other, so the amount of slack of the packaging material 10 absorbed by the buffer portion 28 is minimized. Also, when the movable table 50 is located at the lower limit position, the fixed roller 54, the first movable roller 52, and the second movable roller 56 are farthest apart from each other, so the amount of slack of the packaging material 10 absorbed by the buffer portion 28 is maximized. When the tension acting on the packaging material 10 wound around the first movable roller 52, the fixed roller 54, and the second movable roller 56 increases, the movable table 50 moves upward against its own weight. Also, when the tension acting on the packaging material 10 wound around the first movable roller 52, the fixed roller 54, and the second movable roller 56 becomes smaller than the weight of the movable table 50, the movable table 50 moves downward due to its own weight. The maximum value of the amount of slack of the packaging material 10 absorbed by the buffer portion 28 is equal to or greater than the maximum packaging material length Lmax described later, and in this embodiment, it is approximately the same value as the maximum packaging material length Lmax.

[0023] The maximum value detection unit 30 detects that the amount of slack absorbed by the buffer portion 28 has reached the maximum value. In this embodiment, the maximum detection unit is composed of a proximity sensor or a limit switch that detects that the movable table 50 is located at the lower limit position and supplies a detection signal to the control unit 32.

[0024] The control unit 32 is realized by a computer executing a control program. The control unit 32 controls the printing mechanism 22 to form the printing unit 16 with a single pre-registered printing pitch ΔP, which will be described later, based on the conveyance amount detected by the conveyance amount detection unit 24. Also, when the maximum value detection unit 30 detects the maximum value, the operation of the printing mechanism 22 is stopped. In addition, the control unit 32 controls the printing mechanism 22 based on the conveyance speed of the packaging material 10 detected by the conveyance speed detection unit 26. Specifically, by controlling so that the printing speed of the printing unit 16 by the print head 36 follows the conveyance speed of the packaging material 10, it is intended that the printing unit 16 is accurately printed without being affected by fluctuations in the conveyance speed of the packaging material 10. Such control to make the printing speed of the print head 36 follow the conveyance speed of the packaging material 10 is a control commonly performed in a printer device.

[0025] Here, the package and the packaging material length L1 manufactured by the packaging machine 12 will be described. As shown in FIGS. 2(A)-(D), the packaging machine 12 manufactures a plurality of types of packages with different packaging material lengths L1 while conveying the packaging material 10. As described above, the packaging material length L1 is the length along the conveyance direction in a state where the packaging materials 10 forming the plurality of types of packages are unfolded. Note that the numbers 1-7 in the figure are numbers assigned in order in the conveyance direction to each of the packaging materials 10 forming each package. FIGS. 2(A)-(D) show a case where there are four types of packaging material lengths L1 corresponding to a plurality of types of packages, namely 450 mm, 500 mm, 550 mm, and 600 mm. In this case, if the shortest of the plurality of types of packaging material lengths L1 is defined as the minimum packaging material length Lmin, then Lmin = 450 mm. Also, if the longest of the plurality of types of packaging material lengths L1 is defined as the maximum packaging material length Lmax, then Lmax = 600 mm. In this case, regardless of which of the above four types of packaging material lengths L1 the packaging machine 12 uses to manufacture the package, it is necessary that at least one printing unit 16 is formed on the packaging material 10 of one package. In addition, the number of printing portions 16 formed on the packaging material 10 of one package may be two or more. However, if the number of printing portions 16 is too large, the ink ribbon of the printer device 14 will be wasted. Therefore, it is preferable that the number of printing portions 16 formed on the packaging material 10 of the package is as small as possible.

[0026] As a result of intensive research, the inventors have found the following from FIG. 2. That is, when the interval between adjacent printing portions 16 in the conveyance direction of the packaging material 10 is defined as the printing pitch ΔP, by satisfying the following formula (1), the printing portion 16 is formed at one or two locations on the packaging material 10 of the package with the minimum packaging material length Lmin. In other words, at least one printing portion 16 is formed on the packaging material 10 of the package with the minimum packaging material length Lmin, and three or more printing portions 16 are not formed. From the above, the following mathematical formula is derived. 0.5Lmin < ΔP < Lmin Formula (1) Substituting the above-mentioned minimum packaging material length Lmin = 450 mm into Formula (1), 225 mm < ΔP < 450 mm (1) is obtained. Here, for example, when ΔP = 300 mm, 225 mm < 300 mm < 450 mm (1) is obtained, and Formula (1) is satisfied. Therefore, a single value of the printing pitch ΔP that satisfies Formula (1) based on the minimum packaging material length Lmin is registered in the control unit 32. Then, based on the conveyance amount detected by the conveyance amount detection unit 24, the control unit 32 forms the printing portion 16 with a single registered value of the printing pitch ΔP that satisfies the value defined by Formula (1) by the printing mechanism 22. In this case, the formation of the printing portion 16 by the printing mechanism 22 is performed while the packaging material 10 is being conveyed by the printing receiving roller 38. In actual operation of the printer device 14, the lower limit value of ΔP in Formula (1) is, for example, about 60% of the minimum packaging material length Lmin.

[0027] Figs. 2(A)-(C) show examples of the formation of the printing portion 16 when the length L1 of the packaging material is four types, 450 mm, 500 mm, 550 mm, and 600 mm, and the printing pitch ΔP is 300 mm. The printing portion 16 is shown by hatching. Fig. 2(D) shows an example of the formation of the printing portion 16 when the length L1 of the packaging material is one type, 450 mm, and the printing pitch ΔP is 300 mm. As is clear from Fig. 2, one or two printing portions 16 are formed on the package with the minimum packaging material length Lmin = 450 mm. That is, the printing portion 16 is not formed on the package with the minimum packaging material length Lmin = 450 mm, or three or more printing portions 16 are not formed on the package with the minimum packaging material length Lmin = 450 mm. In addition, when the length L1 of the packaging material is a value larger than the values exemplified in Fig. 2, such as 900 mm which is three times the minimum packaging material length Lmin = 450 mm, 900 mm / ΔP = 900 mm / 300 mm = 3, and there is a possibility that three printing portions 16 are formed on one package. However, since at least three or more printing portions 16 are not formed on the package with the minimum packaging material length Lmin = 450 mm, it is advantageous in suppressing wasteful consumption of the ink ribbon.

[0028] Next, the operations of the packaging machine 12 and the printer device 14 will be described with reference to the flowcharts of Figs. 3 and 4. In the flowcharts of Figs. 3 and 4, when the packaging machine 12 executes the following two types of operations, how the printer device 14 operates corresponding to each operation will be described. 1) Intermittent operation: When the packaging machine 12 intermittently manufactures packages while repeating the operation of pulling out and conveying the packaging material 10 from the printer device 14 and the operation of stopping the conveyance 2) Continuous operation: When the packaging machine 12 continuously pulls out and conveys the packaging material 10 from the printer device 14 and continuously manufactures packages

[0029] Note that in advance, the minimum wrapping material length Lmin is specified from the respective wrapping material lengths L1 of a plurality of packages defined by the specifications of the wrapping machine 12, and a single-value printing pitch ΔP that satisfies the value defined by Expression (1) is registered in the control unit 32. Further, it is assumed that the wrapping material 10 drawn from the original roll 11 is introduced into the wrapping machine 12 via a plurality of guide rollers, a printing mechanism 22, and a buffer unit 28 and is in a state where production of packages is possible. In this case, the movable table 50 of the buffer unit 28 is located at the upper limit position. Therefore, the amount of absorption of the slack of the wrapping material 10 by the buffer unit 28 is at the minimum value.

[0030] As shown in FIG. 3, a product to be wrapped with a wrapping material is loaded into the wrapping machine 12, production of one package by the wrapping machine 12 is started, and the wrapping material 10 is conveyed toward the wrapping machine 12 by the wrapping machine-side conveying unit 18 of the wrapping machine 12 (step S10). Here, since the wrapping material length L1 of one package manufactured by the wrapping machine 12 is within the range of not less than the minimum wrapping material length Lmin and not more than the maximum wrapping material length Lmax, the wrapping material 10 within the range of not less than the minimum wrapping material length Lmin and not more than the maximum wrapping material length Lmax is conveyed from the buffer unit 28 to the wrapping machine 12 by the wrapping machine 12.

[0031] When the wrapping material 10 is conveyed, the start signal generation unit 20 detects that the conveyance of the wrapping material 10 by the wrapping machine 12 has started, generates a start signal, and supplies the start signal to the control unit 32 (step S12). Since the wrapping material 10 is conveyed toward the wrapping machine 12 by the wrapping machine 12, the wrapping material 10 is drawn from the original roll 11, passes through the printing mechanism 22 and the buffer unit 28, and is conveyed from the upstream side to the downstream side. When the control unit 32 receives the start signal, the control unit 32 drives the printing roller 38 by the driving unit 40 based on the conveyance amount detected by the conveyance amount detection unit 24, and forms the printing unit 16 with a single-value printing pitch ΔP registered in advance (step S14).

[0032] The control unit 32 determines whether the conveyance speed of the wrapping material 10 detected by the conveyance speed detection unit 26 has reached the specified speed or is lower than the specified speed (step S16). Here, the specified speed is the printable speed that can be printed by the printing mechanism 22. Therefore, if the determination in step S16 is affirmative (if the conveyance speed of the packaging material 10 has reached the specified speed), it means that the packaging machine 12 is performing continuous operation. On the other hand, if the determination in step S16 is negative (if the conveyance speed of the packaging material 10 is below the specified speed), it means that the packaging machine 12 is performing intermittent operation, and then it proceeds to the flowchart of FIG. 4 described later.

[0033] Note that when the packaging machine 12 is performing continuous operation, it is a prerequisite that the conveyance speed of the packaging material 10 by the packaging machine 12 is set so that the rotational speed of the printing receiving roller 38 becomes higher than a predetermined rotational speed. As described above, the predetermined rotational speed is a value higher than the rotational speed of the printing receiving roller 38 when the packaging machine 12 intermittently manufactures the package. In this case, since the one-way clutch 46 idles, the printing receiving roller 38 is disengaged from the drive unit 40 and rotates following the conveyance of the packaging material 10, so the printing receiving roller 38 does not contribute to the conveyance of the packaging material 10. In this case, as the printing receiving roller 38 rotates following the conveyance of the packaging material 10, the conveyance amount of the packaging material 10 is detected by the conveyance amount detection unit 24.

[0034] Then, the control unit 32 controls the printing mechanism 22 to form the printing unit 16 with a printing pitch ΔP of a single value registered in advance that satisfies the value defined by the formula (1) based on the conveyance amount detected by the conveyance amount detection unit 24. Also, in this case, since the packaging material 10 is continuously conveyed toward the packaging machine 12 by the packaging machine 12, the tension of the packaging material 10 in the buffer unit 28 increases. Therefore, since the movable table 50 maintains the state of being located at the upper limit position, the absorption amount of the slack of the packaging material 10 in the buffer unit 28 is minimized.

[0035] On the other hand, if step S16 is affirmative, the operation of absorbing the slack of the packaging material 10 by the buffer unit 28 is not executed, and the movable table 50 maintains the state of being located at the upper limit position (step S18). Then, the control unit 32 continues the operation of forming the printing unit 16 with a single value of the printing pitch ΔP (step S20). That is, the printing unit 16 is continuously formed at the printing pitch ΔP.

[0036] Then, when the continuous operation of the packaging machine 12 stops, that is, when the conveyance of the packaging material 10 by the packaging machine 12 stops (step S22), as the printing unit 16 is formed, that is, as the printing receiving roller 38 rotates, the packaging material 10 is conveyed from the printing mechanism 22 to the buffer unit 28, and the buffer unit 28 absorbs the slack of the packaging material 10 as the movable table 50 moves from the upper limit position to the lower limit position (step S24). The control unit 32 determines whether the maximum value has been detected by the maximum value detection unit 30 (step S26). If the determination in step S26 is negative, the control unit 32 returns to step S20 and continues the formation of the printing unit 16. If the determination in step S26 is affirmative, the control unit 32 stops the operation of the printing mechanism 22 (step S28). Thereby, the amount of absorption of the slack of the packaging material 10 by the buffer unit 28 becomes the maximum value (a value substantially the same as the maximum packaging material length Lmax). Next, the control unit 32 determines whether a start signal is supplied (step S30). If the determination in step S30 is affirmative, it returns to step S14 and starts the operation of the printing mechanism 22. If the determination in step S30 is negative, it returns to step 30 and waits for the supply of the start signal.

[0037] Next, with reference to the flowchart of FIG. 4, the case where the determination in step S16 is negative, that is, the case where the packaging machine 12 executes an intermittent operation will be described. With the formation of the printing unit 16, that is, as the printing roller 38 rotates, the packaging material 10 is conveyed from the printing mechanism 22 to the buffer unit 28, and the buffer unit 28 absorbs the slack of the packaging material 10 as the movable table 50 moves from the upper limit position to the lower limit position (step S32). The packaging material 10 is conveyed at a speed lower than the specified speed. As long as the amount of slack absorption of the packaging material 10 by the buffer unit 28 does not reach the maximum value, the operation of absorbing the slack of the packaging material 10 by the buffer unit 28 and the operation of forming the printing unit 16 are repeatedly executed. Note that in a state where the packaging machine 12 is performing an intermittent operation, although the conveyance of the packaging material 10 intermittently stops, the amount of slack absorption of the packaging material 10 by the buffer unit 28 is maintained in a state where it does not reach the maximum value, and the movable table 50 of the buffer unit 28 stays at an intermediate position between the upper limit position and the lower limit position. The conveyance amount and conveyance speed of the packaging material 10 by the packaging machine 12 are set accordingly.

[0038] Then, when the intermittent operation of the packaging machine 12 stops, that is, when the conveyance of the packaging material 10 by the packaging machine 12 is stopped (step S34), with the formation of the printing unit 16, that is, as the printing roller 38 rotates, the packaging material 10 is conveyed from the printing mechanism 22 to the buffer unit 28, and the buffer unit 28 absorbs the slack of the packaging material 10 as the movable table 50 moves from the upper limit position to the lower limit position (step S36). The control unit 32 determines whether the maximum value has been detected by the maximum value detection unit 30 (step S38). If the determination in step S38 is negative, the control unit 32 returns to step S38 and continues forming the printing unit 16. If the determination in step S38 is positive, the control unit 32 stops the operation of the printing mechanism 22 (step S40). As a result, the amount of slack absorption of the packaging material 10 by the buffer unit 28 reaches the maximum value (a value almost the same as the maximum packaging material length Lmax). Next, the control unit 32 determines whether a start signal is being supplied (step S42). If the determination in step S42 is positive, it returns to step S14 and starts the operation of the printing mechanism 22. If the determination in step S42 is negative, return to step S42 and wait for the supply of the activation signal.

[0039] According to the present embodiment, when the shortest among the plurality of types of wrapper lengths L1 is defined as the minimum wrapper length Lmin, and the interval between adjacent printing units 16 in the conveyance direction of the wrapper 10 is defined as the printing pitch ΔP, the control unit 32 controls the printing mechanism 22 to form the printing unit 16 with a single registered value of the printing pitch ΔP that satisfies the following formula (1) based on the conveyance amount detected by the conveyance amount detection unit 24. 0.5Lmin < ΔP < Lmin Formula (1) Therefore, even when there is no registration mark formed on the wrapper 10, and even when a predetermined printing signal is not supplied to the printer device 14 for each package from the packaging machine 12, it is advantageous for the printer device 14 to surely form the printing unit 16 so that there is no omission of the printing unit 16 for each of the plurality of types of packages having different wrapper lengths L1. Also, when the packaging machine 12 is an intermittent packaging machine that intermittently manufactures packages while repeating the operation of pulling out the wrapper 10 from the printer device 14 and conveying it and the operation of stopping the conveyance, if the wrapper 10 is very thin and highly stretchable, the packaging machine 12 intermittently conveys the wrapper 10, and the conveyance and stop of the wrapper 10 are repeated, so that the expansion and contraction of the wrapper 10 occur along the conveyance direction, and there is a concern that the dimension of the wrapper 10 in the conveyance direction changes. However, as described above, since the printing unit 16 is formed with a single registered value of the printing pitch ΔP, one or two printing units 16 can be surely formed on the package with the minimum wrapper length Lmin, and it is advantageous for the printer device 14 to surely form the printing unit 16 so that there is no omission of the printing unit 16 for each of the plurality of types of packages having different wrapper lengths L1. Also, when the packaging machine 12 is a continuous packaging machine that continuously pulls out the packaging material 10 from the printer device 14 and manufactures the package while transporting the packaging material 10, if the packaging material 10 is very thin and highly stretchable, at the start and stop of the packaging machine 12, when the packaging material 10 starts and stops being transported, there is a concern that the packaging material 10 will stretch and contract along the transport direction, and the dimensions of the packaging material 10 in the transport direction will change. Also, even when the transport operation of the packaging material 10 by the packaging machine 12 stops during printing by the printer device 14, there is a concern that when the transport of the packaging material 10 stops, the packaging material 10 will stretch and contract along the transport direction, and the dimensions of the packaging material 10 in the transport direction will change. However, also in such a continuous packaging machine, similar to the case of the intermittent packaging machine described above, since the printing unit 16 is formed with the printing pitch ΔP of a single value registered in advance as described above, it is possible to surely form one or two printing units 16 on the package with the minimum packaging material length Lmin, which is advantageous in surely forming the printing unit 16 so that there is no omission of the printing unit 16 for each of a plurality of types of packages having different packaging material lengths L1 by the printer device 14.

[0040] Also, in the present embodiment, the packaging machine 12 intermittently executes the manufacture of the package while repeating the operation of pulling out and transporting the packaging material 10 from the printer device 14 and the operation of stopping the transport. The printer device 14 includes a start signal generation unit 20 that detects that the transport of the packaging material 10 by the packaging machine 12 has started and generates a start signal, and the control unit 32 controls the printing mechanism 22 based on the start signal. Also, even when the packaging machine 12 continuously executes the manufacture of the package while pulling out and transporting the packaging material 10 from the printer device 14, the printer device 14 includes a start signal generation unit 20 that detects that the transport of the packaging material 10 by the packaging machine 12 has started and generates a start signal, and the control unit 32 controls the printing mechanism 22 based on the start signal. Therefore, even when the packaging machine 12 does not have a function of supplying a control signal (printing signal) for instructing the timing for forming the printing unit 16 at an appropriate position for each of a plurality of types of packages having different wrapper lengths L1, it is advantageous for reliably forming the printing unit 16 so that there is no omission of the printing unit 16 for each of a plurality of types of packages having different wrapper lengths L1.

[0041] Also, in the present embodiment, a buffer unit 28 capable of absorbing the slack of the wrapper 10 is provided on the downstream side of the printing mechanism 22. Therefore, when the packaging machine 12 intermittently manufactures packages while repeating the operation of pulling out and conveying the wrapper 10 from the printer device 14 and the operation of stopping the conveyance, the slack of the wrapper 10 generated can be absorbed by the buffer unit 28, which is advantageous for smoothly and reliably forming the printing unit 16 by the printer device 14. Also, even when the packaging machine 12 continuously manufactures packages while pulling out and conveying the wrapper 10 from the printer device 14, the slack of the wrapper 10 generated at the start-up and shut-down of the conveyance of the wrapper 10, or the slack of the wrapper 10 generated due to the stop of the conveyance operation of the wrapper 10 by the packaging machine 12 during printing by the printer device 14 can be absorbed by the buffer unit 28, which is advantageous for smoothly and reliably forming the printing unit 16 by the printer device 14. Also, whether the packaging machine 12 is an intermittent packaging machine or a continuous packaging machine, the slack of the wrapper 10 generated due to the indefinite conveyance speed when pulling out and conveying the wrapper 10 from the printer device 14 can be absorbed by the buffer unit 28, which is advantageous for smoothly and reliably forming the printing unit 16 by the printer device 14.

[0042] In addition, in the present embodiment, the maximum value of the amount of absorption of the slack of the packaging material 10 by the buffer unit 28 is equal to or greater than the maximum packaging material length Lmax, and a maximum value detection unit 30 is provided for detecting that the amount of absorption of the slack by the buffer unit 28 has reached the maximum value. When the maximum value is detected by the maximum value detection unit 30, the control unit 32 stops the operation of the printing mechanism 22. Therefore, it is possible to prevent the occurrence of slack in the packaging material 10 that cannot be absorbed by the buffer unit 28, which is more advantageous for smoothly and reliably forming the printing unit 16 by the printer device 14.

[0043] In addition, in the present embodiment, the printing mechanism 22 includes a print head 36, a printing roller 38, and a drive unit 40 that rotationally drives the printing roller 38 to convey the packaging material 10. The conveyance amount detection unit 24 includes a first encoder 2402 that outputs a first detection signal corresponding to the rotation amount of the printing roller 38, and the detection of the conveyance amount of the packaging material 10 by the conveyance amount detection unit 24 is performed based on the first detection signal. Therefore, it is possible to reliably detect the conveyance amount of the packaging material 10 passing through the printing mechanism 22, which is more advantageous for smoothly and reliably forming the printing unit 16 by the printer device 14.

[0044] In addition, in the present embodiment, the printing mechanism 22 is provided with a conveyance speed detection unit 26 for detecting the conveyance speed of the packaging material 10 wound around the printing roller 38, and the control of the printing mechanism 22 by the control unit 32 is performed based on the conveyance speed of the packaging material 10 detected by the conveyance speed detection unit 26. Therefore, the printing unit 16 can be accurately printed without being affected by fluctuations in the conveyance speed of the packaging material 10, which is advantageous for improving the quality of the printing unit 16.

[0045] In addition, in the present embodiment, the drive unit 40 includes a drive motor 42 and a one-way clutch 46 that transmits the rotational driving force of the drive motor 42 to the printing roller 38 and idles when the rotational speed of the printing roller 38 becomes equal to or higher than the rotational speed of the drive unit 40. In addition, in the present embodiment, the drive unit 40 includes a drive motor 42 and a rotational drive force transmission unit, such as a one-way clutch 46, that transmits the rotational drive force of the drive motor 42 to the printing platen roller 38. When the rotational speed of the printing platen roller 38 becomes higher than a predetermined rotational speed, the rotational drive force transmission unit disconnects the drive motor 42 from the printing platen roller 38 to stop the transmission of the rotational drive force of the drive motor 42 to the printing platen roller 38. Therefore, even when the packaging machine 12 continuously pulls out and conveys the packaging material 10 from the printer device 14 and continuously manufactures the packages, it is possible to form the printing unit 16 at a pre-registered printing pitch ΔP. Therefore, whether the packaging machine 12 intermittently manufactures the packages or continuously manufactures the packages, it is advantageous for smoothly and surely forming the printing unit 16 by the printer device 14, and it is advantageous for improving the convenience of the printer device 14.

[0046] (Second Embodiment) Next, the second embodiment will be described. In the first embodiment, the case where the packaging machine 12 is, for example, a horizontal pillow packaging machine or a vertical pillow packaging machine, the manufactured packages are separated and independent from each other, and a plurality of types of packages having different packaging material lengths L1 are manufactured has been described. In contrast, in the second embodiment, the case where the packaging machine 12 manufactures one single package in which the product to be packaged is packaged using the packaging material 10, or a continuous package in which N (N is a natural number) single packages are connected in the conveyance direction of the packaging material 10 will be described. For example, as a single package, there is an example of a unit container that is open upward and houses tofu or jelly (product to be packaged), and a packaging material 10 that seals the opening of the unit container. As a continuous package, there is an example of a package of tofu or jelly formed by arranging and connecting a plurality of these single packages in the conveyance direction of the packaging material 10. Alternatively, an example is where the unit package is a single pouch containing a snack (the product to be packaged), and the continuous package is a continuous pouch formed by connecting a plurality of such single pouches. Note that, similar to the package in the first embodiment, the size of the single package in the second embodiment has variations (individual differences), and thus, the size of the continuous package also has variations. That is, in the second embodiment, there are multiple types of single packages with different lengths along the conveyance direction of the packaging material 10, and there are also multiple types of continuous packages with different lengths along the conveyance direction of the packaging material 10.

[0047] Referring to FIG. 1 for explanation, also in the second embodiment, similar to the first embodiment, the packaging machine 12 manufactures a package containing a product using the packaging material pulled out from the printer device 14 and conveyed. That is, the packaging machine 12 may intermittently execute the production of single packages or continuous packages while repeating the operation of pulling out the packaging material 10 from the printer device 14 and conveying it and the operation of stopping the conveyance, or may continuously execute the production of single packages or continuous packages while pulling out the packaging material 10 from the printer device 14 and conveying it. Also, the packaging machine 12 does not have a function of supplying a control signal (printing signal) for instructing the timing for forming the printing unit 16 at an appropriate position to the printer device 14. In the second embodiment, the point that the printer device 14 forms the printing unit 16 on the packaging material 10 at a pre-registered printing pitch ΔP is the same as in the first embodiment.

[0048] The basic configuration of the printer device 14 is the same as in the first embodiment, and includes a start signal generation unit 20, a printing mechanism 22, a conveyance amount detection unit 24, a buffer unit 28, a maximum value detection unit 30, and a control unit 32. Hereinafter, the points different from the first embodiment will be mainly described, and the description of the same parts and members will be omitted.

[0049] The length along the conveyance direction in the state where the packaging material 10 forming a single package is unfolded is defined as the individual package material length Lp, and the length along the conveyance direction in the state where the packaging material 10 forming a continuous package is unfolded is defined as the overall package material length Lw. When the packaging machine 12 manufactures one single package, at least one printing part 16 must be formed on the packaging material 10 of one single package. Also, when the packaging machine 12 manufactures a continuous package, at least one printing part 16 must be formed on each single package constituting the continuous package. Also, the number of printing parts 16 formed on the packaging material 10 of one single package may be two or more. However, if the number of printing parts 16 is too large, the ink ribbon of the printer device 14 will be consumed wastefully. Therefore, it is preferable that the number of printing parts 16 formed on the packaging material 10 of one single package is at most two.

[0050] As a result of intensive research, the inventors have found the following. That is, when the interval between adjacent printing parts 16 in the conveyance direction of the packaging material 10 is defined as the printing pitch ΔP, by satisfying the following formula (2), the printing part 16 is formed at one or two locations on the packaging material 10 of one single package. In other words, at least one printing part 16 is formed on the packaging material 10 of one single package, and three or more printing parts 16 are not formed. From the above, the following mathematical formula is derived. 0.5Lp < ΔP < Lp Formula (2) Specifically, For example, assume that the individual package material length Lp = 70 mm. Substituting this value into Formula (2), 35 mm < ΔP < 70 mm Formula (2) Therefore, the control unit 32 controls the printing mechanism 22 to form the printing part 16 with a printing pitch ΔP of a single registered value that satisfies the following formula (2) based on the conveyance amount detected by the conveyance amount detection unit 24. 0.5Lp < ΔP < Lp Formula (2)

[0051] Therefore, according to the second embodiment, even when there is no registration mark formed on the packaging material 10, and even when a predetermined printing signal is not supplied to the printer device 14 for each unit package or for each continuous package from the packaging machine 12, the following effects can be achieved. That is, since the printing unit 16 is formed with a printing pitch ΔP of a single registered value that satisfies the above formula (2) based on the conveyance amount detected by the conveyance amount detection unit 24, one or two printing units 16 are formed on a plurality of types of unit packages having different lengths along the conveyance direction of the packaging material 10, and one or two printing units 16 are formed on each unit package that constitutes a plurality of types of continuous packages having different lengths along the conveyance direction of the packaging material 10. In other words, the printing unit 16 is not formed on the unit package, and three or more printing units 16 are not formed on one unit package, so that the ink ribbon is not wasted. Therefore, even when manufacturing a plurality of types of single packages having different lengths along the conveyance direction of the packaging material 10 in the packaging machine 12, or when manufacturing a plurality of types of continuous packages having different lengths along the conveyance direction of the packaging material 10 in which N single packages are connected, it is advantageous for reliably forming the printing unit 16 so that there is no omission of the printing unit 16 for each single package. Also, when the packaging machine 12 is an intermittent packaging machine that intermittently manufactures packages while repeating the operation of pulling out the packaging material 10 from the printer device 14 and conveying it and the operation of stopping the conveyance, if the packaging material 10 is very thin and highly stretchable, when the packaging machine 12 intermittently conveys the packaging material 10, the stretching and contraction of the packaging material 10 occurs along the conveyance direction due to the repeated conveyance and stop of the packaging material 10, and there is a concern that the dimension of the packaging material 10 in the conveyance direction may change. However, as described above, since the printing unit 16 is formed with a printing pitch ΔP of a single registered value, it is more advantageous for reliably forming the printing unit 16 so that there is no omission of the printing unit 16 for each single package or for each of the N single packages that constitute a continuous package. Also, when the packaging machine 12 is a continuous packaging machine that continuously pulls out the packaging material 10 from the printer device 14 and manufactures a package while transporting the packaging material 10, if the packaging material 10 is very thin and highly stretchable, at the start and stop of the packaging machine 12, the packaging material 10 may stretch and contract along the transport direction during the start-up and shut-down of the transport of the packaging material 10, and there is a concern that the dimensions of the packaging material 10 in the transport direction may change. Also, even when the transport operation of the packaging material 10 by the packaging machine 12 stops during printing by the printer device 14, there is a concern that the packaging material 10 may stretch and contract along the transport direction at the stop of the transport of the packaging material 10, and the dimensions of the packaging material 10 in the transport direction may change. However, even in such a continuous packaging machine, similar to the case of the intermittent packaging machine described above, since the printing unit 16 is formed with the printing pitch ΔP of a single value registered in advance as described above, it is more advantageous in reliably forming the printing unit 16 so that there is no omission of the printing unit 16 for each of the N single packages constituting one single package or a continuous package. Also, in the second embodiment as well, in addition to the effects described above, it goes without saying that the same effects as those described in the first embodiment are achieved. In the first and second embodiments, a configuration in which the control unit 32 that controls the printer device 14 is provided in the printer device 14 has been described. However, in short, as long as the control unit 32 can control the printer device 14, the function of the control unit 32 may be realized by also using the packaging machine side control unit that controls the packaging machine 12, or a control device independent of the printer device 14 and the packaging machine 12 may be provided, and that control device may realize the function of the control unit 32. That is, it goes without saying that the function of the control unit 32 may be realized according to various specifications and conditions required for the printing method control system (constant pitch printing system) including the printer device 14 and the packaging machine 12.

Explanation of Reference Numerals

[0052] 10 Packaging material 11 Parent roll 12 Packaging machine 14 Printer device 16 Printing unit 18 Packaging Machine Side Conveyor Section 1802 Driving Roller 1804 Driven Roller 1806 First Driving Motor 20 Start Signal Generation Section 2002 Encoder for Start Signal 22 Printing Mechanism 24 Conveying Amount Detection Section 2402 First Encoder 26 Conveying Speed Detection Section 2602 Driven Roller 2604 Second Encoder 28 Buffer Section 30 Maximum Value Detection Section 32 Control Section 33 Conveying Speed Calculation Section 34 Housing 36 Print Head (Thermal Head) 38 Printing Receiving Roller 3802 Roller Body 3804 Rotating Shaft 40 Driving Section 42 Driving Motor 44 Power Transmission Mechanism 4402 Driving Pulley 4404 Driven Pulley 4406 Belt 46 One-Way Clutch (Rotational Driving Force Transmission Section) 48 Slide Rail 50 Movable Table 52 First Movable Roller 54 Fixed Roller 56 Second Movable Roller 58A Upper Limit Stopper 58B Lower Limit Stopper G1 - G13 Guide Roller

Claims

1. A printer device disposed upstream in the conveying direction of a packaging material of a packaging machine that manufactures a package in which a product is accommodated by a packaging material, the printer device including a printing mechanism that forms a printing portion while conveying the long packaging material conveyed from the upstream side to the downstream side. The packaging machine manufactures a plurality of types of packages having different lengths along the conveying direction while conveying the packaging material. A conveyance amount detection unit is provided for detecting the conveyance amount of the packaging material passing through the printing mechanism. The length along the conveying direction in a state where the packaging materials forming the plurality of types of packages are developed is defined as a packaging material length L1. The shortest of the plurality of types of packaging material lengths L1 is defined as a minimum packaging material length Lmin. When the interval between adjacent printing portions in the conveying direction of the packaging material is defined as a printing pitch ΔP. A control unit that controls the printing mechanism to form the printing portion with the printing pitch ΔP, which is a single registered value satisfying the following formula (1) based on the conveyance amount detected by the conveyance amount detection unit. A printer device characterized by the above. 0.5Lmin < ΔP < Lmin Formula (1)

2. The packaging machine manufactures the package using the packaging material pulled out from and conveyed by the printer device. The printer device includes an activation signal generation unit that detects the start of conveyance of the packaging material by the packaging machine and generates an activation signal. The control unit controls the printing mechanism based on the activation signal. The printer device according to claim 1, characterized by the above.

3. A buffer unit capable of absorbing slack of the packaging material is provided on the downstream side of the printing mechanism. The printer device according to claim 2, characterized by the above.

4. When the longest of the plurality of types of packaging material lengths L1 is defined as a maximum packaging material length Lmax. The maximum value of the absorption amount of the slack of the packaging material by the buffer unit is equal to or greater than the maximum packaging material length Lmax. A maximum value detection unit is provided for detecting that the absorption amount of the slack by the buffer unit has reached the maximum value. The control unit stops the operation of the printing mechanism when the maximum value is detected by the maximum value detection unit. The printer device according to claim 3, characterized by the above.

5. The printing mechanism includes a print head, a printing roller that can rotate while sandwiching the packaging material between the print head, and a drive unit that rotationally drives the printing roller to convey the packaging material. The conveyance amount detection unit includes a first encoder that outputs a first detection signal corresponding to the rotation amount of the printing receiving roller, detection of the conveyance amount of the packaging material by the conveyance amount detection unit is performed based on the first detection signal, The printer device according to claim 1, characterized in that.

6. The drive unit includes a drive motor and a rotational drive force transmission unit that transmits the rotational drive force of the drive motor to the printing receiving roller, When the rotational speed of the printing receiving roller becomes higher than a predetermined rotational speed, the rotational drive force transmission unit disconnects the drive motor from the printing receiving roller and stops transmitting the rotational drive force of the drive motor to the printing receiving roller, The printer device according to claim 5, characterized in that.

7. The printing mechanism includes a conveyance speed detection unit that detects the conveyance speed of the packaging material wound around the printing receiving roller, control of the printing mechanism by the control unit is performed based on the conveyance speed of the packaging material detected by the conveyance speed detection unit, The printer device according to claim 1, characterized in that.

8. A printer device disposed upstream in the conveyance direction of a packaging material of a packaging machine that manufactures a package in which a product is accommodated by the packaging material, the printer device including a printing mechanism that forms a printing unit while conveying the packaging material on a long packaging material conveyed from upstream to downstream, The packaging machine manufactures a plurality of types of single packages having different lengths along the conveyance direction while conveying the packaging material, or a plurality of types of continuous packages having different lengths along the conveyance direction formed by connecting N (N is a natural number of 2 or more) of the single packages in the conveyance direction, a conveyance amount detection unit for detecting the conveyance amount of the packaging material passing through the printing mechanism is provided, When the length along the conveyance direction in a state where the packaging material forming the single package is unfolded is defined as the individual packaging material length Lp, when the interval between adjacent printing units in the conveyance direction of the packaging material is defined as the printing pitch ΔP, a control unit that controls the printing mechanism to form the printing unit with the printing pitch ΔP of a single registered value that satisfies the following formula (2) based on the conveyance amount detected by the conveyance amount detection unit, The printer device, characterized in that. 0.5Lp < ΔP < Lp Formula (2)

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