JP7433593B2 - inkjet printing device - Google Patents

Description

The present invention relates to an inkjet printing device that has a plurality of conveyance paths for a printing substrate and is capable of performing front-side printing and back-side printing with one device by switching the conveyance paths.

An inkjet printing device prints designs such as letters and patterns by making ink into fine droplets and spraying them directly onto a substrate to be printed.
Inkjet printing devices are capable of printing a desired design on a printing substrate at a desired position and at a desired timing, and therefore, printing that takes advantage of this characteristic is performed in various fields.

For example, in the case of packaging bags for products, designs are printed on the front or back of the film.
In addition, front printing means that when the printing substrate is made into a bag shape, the printing surface is on the outside, and back printing means that when the printing substrate is made into a bag shape, the printing surface is on the outside. The printed surface is on the inside.
Incidentally, when it is desired to print a background image and a design image as a design for a packaging bag, the order of printing is reversed for front printing and back printing.

Incidentally, an inkjet printing device that can perform front and back printing using inkjet has been developed.
Specifically, at least in the case of front printing, a first white inkjet head that discharges white water-based ink onto the surface of a web-like printing base material, a first drum type drying unit that dries this, and a first drum type drying unit that dries this, and a single-pass inkjet head that ejects non-white water-based ink onto the surface of the web-like printing substrate in the case of reverse printing; An inkjet printer is known that includes a second white inkjet head that ejects white inkjet head and a second drum type drying unit that dries the white inkjet head (for example, see Patent Document 1).

Patent No. 6916907

However, in the inkjet printer described in Patent Document 1, in order to realize front and back printing, it is necessary to provide a first white inkjet head and a second white inkjet head in addition to the normal inkjet head. be. In this case, since at least three parts are required to be printed, there is a drawback that the apparatus becomes larger.
In addition, in the case of reverse printing, white ink is ejected from the second white inkjet head immediately after the non-white water-based ink is ejected from the inkjet head, so these inks may mix with each other on the web-like printing substrate. , color mixing such as bleeding may occur.
Note that if a drying device is added to the transport path between the ejection of non-white water-based ink and the ejection of white ink from the second white inkjet head, color mixing can be suppressed by drying, but the device will become larger.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an inkjet printing device that is compact, prevents color mixture from occurring, and is capable of printing on both front and back sides. .

The inventors of the present invention have made extensive studies to solve the above problems, and have decided to provide two parts for printing, a first printing part and a second printing part, and as a conveyance path for the printing substrate. It has been found that the above-mentioned problem can be solved by having at least a first conveyance path and a second conveyance path, and by switching these conveyance paths, and have completed the present invention.

The present invention is an inkjet printing device that has a plurality of conveyance paths for a substrate to be printed, and can reverse the printing order between a first printing section and a second printing section by switching the conveyance paths. , a supply section for supplying a printing substrate, a first printing section and a second printing section for printing and drying the printing substrate, and a discharge section for collecting the printed printing substrate. and a supply section, a first printing section, a second printing section, and a discharge section are arranged in series in this order, and at least the first printing section and the second printing section are arranged on one side of the printing substrate. This is an inkjet printing device having a first conveyance path that performs printing in the order of the first printing section, and a second conveyance path that performs printing in the order of the second printing section and the first printing section.

In the present invention, an upstream base point roller is provided between the supply section and the first printing section, a downstream base point roller is provided between the second printing section and the discharge section, and the first printing section The section includes a first entrance roller for guiding the printing substrate into the first printing section, and a first exit roller for guiding the printing substrate from the first printing section to the outside. The second printing section includes a second inlet roller for guiding the printing substrate into the second printing section, and a second inlet roller for guiding the printing substrate from the second printing section to the outside. In the first conveyance path, the substrate to be printed is conveyed from the upstream base point roller to the first entrance roller, from the first exit roller to the second entrance roller, and in the first conveyance path, the printing substrate is conveyed from the upstream base point roller to the second entrance roller, and then In the second conveyance path, the printing substrate is conveyed from the upstream base roller to the second entrance roller, and from the second exit roller to the first entrance roller. It is preferable that the roller be conveyed from the first exit roller to the downstream base point roller.

In the present invention, it is preferable that the first entrance roller, the first exit roller, the second entrance roller, and the second exit roller are provided with gripping means for gripping the printing target substrate.

The present invention further includes a pretreatment section for forming an ink receiving layer on the printing substrate, the pretreatment section being disposed between the supply section and the first printing section, and the pretreatment section being arranged between the supply section and the first printing section. , preferably includes an upstream base point roller, and the upstream base roller guides the printing substrate from the pretreatment section to the outside.

In the present invention, a work space is provided between the pre-processing section and the first printing section and between the first printing section and the second printing section, respectively, for performing a switching operation. Preferably, the first conveyance path and the second conveyance path are provided above the work space.

The present invention further includes a post-processing section for forming an overcoat layer on the printing substrate, the post-processing section being disposed between the second printing section and the discharge section, and the post-processing section being arranged between the second printing section and the discharge section. It is preferable that the printing apparatus has a downstream base point roller, and that the downstream base roller guides the printing substrate into the interior of the post-processing section.

In the present invention, the ink used for printing in one of the first printing section and the second printing section is at least one selected from the group consisting of yellow ink, magenta ink, cyan ink, and black ink, On the other hand, it is preferable that the ink used for printing is white ink.

In the present invention, an unused printing substrate is provided on the transport route that is not used between the first transport route and the second transport route, and that does not overlap with the first transport route and the second transport route. It is preferable that materials are arranged.
At this time, it is preferable that holding means for holding the unused printing substrate be attached to the rollers located at both ends of the unused printing substrate.

In the present invention, the printing substrate is preferably a transparent or translucent film for packaging.

Since the inkjet printing device of the present invention only needs to include at least the first printing section and the second printing section as parts for printing, the device itself can be made compact.
In addition, in the first printing section and the second printing section, after each printing is performed, drying is performed separately, so there is no need to add a new drying device, and color mixing can be prevented. can.
In addition, as a conveyance path for the printing substrate, a first conveyance path in which printing is performed in the order of the first printing part and the second printing part, and a second conveyance path in which printing is performed in the order of the second printing part and the first printing part. By switching these transport routes, the order of printing by the first printing section and printing by the second printing section on the printing target substrate can be reversed. That is, by switching between the first conveyance path and the second conveyance path, back printing and front printing can be performed without replacing ink in the printing section.
Note that replacing ink is time-consuming and may cause color differences between lots.

Specifically, in the first conveyance path, the printing substrate is conveyed from the upstream base point roller to the first entrance roller, conveyed from the first exit roller to the second entrance roller, and from the second exit roller to the downstream side. In the second conveyance path, the substrate to be printed is conveyed from the upstream base roller to the second entrance roller, from the second exit roller to the first entrance roller, and then The material may be conveyed from the first exit roller to the downstream base point roller.
Therefore, the conveyance path of the printing substrate can be changed relatively easily by switching the conveyance between these rollers.

In the inkjet printing device of the present invention, the first inlet roller, the first outlet roller, the second inlet roller, and the second outlet roller have gripping means for gripping the printing substrate, so that the printing substrate can be can be gripped at each roller position.
Therefore, by holding the printing base material, it is possible to more easily switch the conveyance route.

In the inkjet printing device of the present invention, a work space for performing a switching operation is provided at least between the preprocessing section and the first printing section and between the first printing section and the second printing section. This makes switching work easier.
In addition, by providing the first conveyance path and the second conveyance path above the work space, dust generated when people enter and leave the work space is prevented from adhering to the printing substrate being conveyed along the conveyance path. This can be prevented as much as possible.

In the inkjet printing device of the present invention, the transport path that is not used between the first transport path and the second transport path and that does not overlap with the first transport path and the second transport path is not used. By arranging the printing substrate, for example, when switching the conveyance path, the printing substrate on the original conveyance path is cut at a predetermined position, and the end and the end of the unused printing substrate are cut. Since the substrate to be printed can be placed on a new conveyance path simply by connecting the parts, it becomes possible to perform the work of switching the conveyance path even more easily.
In addition, if holding means for holding the unused printing substrate are attached to the rollers located at both ends of the unused printing substrate, the operation can be performed by holding the printing substrate. At times, it is possible to prevent unused printing substrates from falling, and at the time of switching, it is possible to more easily perform the work of switching conveyance routes.

Since the inkjet printing device of the present invention includes the pretreatment section, the formation of the ink-receiving layer and printing can be performed in a series of steps.
Further, by providing the pre-processing section with the upstream base point roller, the apparatus can be made more compact.

Since the inkjet printing device of the present invention includes a post-processing section, printing and formation of an overcoat layer can be performed in a series of steps.
Further, by providing the post-processing section with the downstream base point roller, the apparatus can be made more compact.

In the inkjet printing device of the present invention, the ink used for printing in one of the first printing section and the second printing section is at least one selected from the group consisting of yellow ink, magenta ink, cyan ink, and black ink. On the other hand, when the ink used for printing is white ink, front printing or back printing using color ink and white ink can be performed while suppressing color mixing.
At this time, by using a transparent or translucent film as the printing substrate, it can be suitably used for packaging products.

FIG. 1 is a side view schematically showing a first embodiment of an inkjet printing device according to the present invention. FIG. 2 is a partial side view for explaining the first conveyance path in the inkjet printing apparatus according to the first embodiment. FIG. 3 is a partial side view for explaining the second conveyance path in the inkjet printing apparatus according to the first embodiment. FIG. 4 is a principle diagram for explaining switching between the first conveyance path and the second conveyance path in the inkjet printing apparatus according to the first embodiment. FIG. 5A is a schematic cross-sectional view showing a back-printed product for food packaging manufactured using the inkjet printing device according to the first embodiment. FIG. 5(b) is a schematic cross-sectional view showing a front printed matter for food packaging manufactured using the inkjet printing device according to the first embodiment. FIG. 6 is a partial side view for explaining the first conveyance path in the inkjet printing device according to the second embodiment. FIG. 7 is a partial side view for explaining the second conveyance path in the inkjet printing device according to the second embodiment.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings as necessary.
In addition, in the drawings, the same elements are given the same reference numerals, and overlapping explanations will be omitted.
In addition, the positional relationships such as top, bottom, left, and right are based on the positional relationships shown in the drawings unless otherwise specified. Furthermore, the dimensional ratios in the drawings are not limited to the illustrated ratios.

The inkjet printing device according to the present invention is a device that prints on a printing target substrate using an inkjet method.
Furthermore, as will be described later, the inkjet printing device according to the present invention includes two parts for printing, and by switching the conveyance path of the printing substrate, the order of printing can be reversed. is possible.
That is, by switching between the first conveyance path and the second conveyance path, it is possible to perform front and back printing.

The material for the printing base material is not particularly limited, such as paper, cloth, nonwoven fabric, film, rubber, metal, etc., but as described later, when it is used for product packaging and front and back printing is performed, It is preferable to employ a transparent or translucent film.
Further, as the inkjet method, on-demand inkjet such as a piezo method or a thermal method can be suitably employed.
Furthermore, as the print head system, a serial head system or a line head system can be adopted.
Note that the inkjet printing apparatus according to the first embodiment and the inkjet printing apparatus according to the second embodiment, which will be described later, employ a line head method.

Here, in this specification, "upstream" means upstream of the printing substrate X in the conveyance path of the printing substrate X, and "downstream" means the upstream of the printing substrate X in the conveyance path of the printing substrate X. In the conveyance route, it means downstream with respect to the conveyance direction of the printing substrate X.
Further, in the inkjet printing device, the supply section side is referred to as the "front", and the discharge section side is referred to as the "rear". That is, the left side of the paper in FIG. 1 is the front, and the right side of the paper is the rear.

(First embodiment)
First, an inkjet printing device according to a first embodiment will be described.
FIG. 1 is a side view schematically showing a first embodiment of an inkjet printing device according to the present invention.
As shown in FIG. 1, an inkjet printing apparatus 100 according to the first embodiment includes a supply unit 1 for supplying a printing substrate X, and a pretreatment for forming an ink receiving layer on the printing substrate X. section 2, a first printing section 3 and a second printing section 4 for printing and drying on the printing substrate X, a post-processing section 5 for forming an overcoat layer on the printing substrate X, and a printing section 5 for forming an overcoat layer on the printing substrate X. The printing apparatus includes an image reading section 7 for reading the printed image, and a discharging section 6 for collecting the printed substrate X.
In this inkjet printing device 100, a supply section 1, a pre-processing section 2, a first printing section 3, a second printing section 4, a post-processing section 5, an image reading section 7, and a discharge section 6 are arranged in series in this order. There is.

Since the inkjet printing device 100 only needs to include at least the first printing section 3 and the second printing section 4, the device itself can be made compact.
In addition, in the inkjet printing device 100, drying is performed after each of the first printing section 3 and the second printing section 4 prints, so there is no need to add a new drying device, and color mixing may occur. It can be prevented.
Furthermore, since the inkjet printing device 100 includes the pre-processing section 2 and the post-processing section 5, it is possible to perform the formation of the ink receiving layer, printing and drying, and the formation of the overcoat layer in a series of steps. .

The supply unit 1 is a part for supplying the printing substrate X, and includes a supply shaft 10 to which the printing substrate X wound into a roll is attached, and a feed roller 13 for sending out the printing substrate X. , a nip roller 13a pressed against the circumferential surface of the feed roller 13, and a housing 1a that accommodates these.
In addition to these, the supply unit 1 includes a meandering prevention device 11 for preventing meandering of the printing substrate X and a dancer 12 for adjusting the tension of the printing substrate X, in the housing 1a. , and a tension detection device 14 for detecting the tension of the printing substrate X.
Note that in the supply section 1, the feed roller 13 is a driving roller.

In the supply section 1, the printing substrate X is held between the feeding roller 13 and the nip roller 13a, and the feeding roller 13 is rotationally driven by a drive motor (not shown), so that the feeding shaft 10 is rotated and the printing substrate X is held between the feeding roller 13 and the nip roller 13a. X is now sent out.
At this time, since rotational resistance is applied to the supply shaft 10 by a powder brake, a tension corresponding to the magnitude of the rotational resistance (braking force) is applied to the printing substrate X. .

In addition, in the supply unit 1, the meandering prevention device 11 detects the position of the printing substrate X in the width direction, and if it deviates from the normal position, moves the printing substrate X in the width direction and positions it. is designed to be adjusted.
In addition, in the supply unit 1, a tension detection device 14 detects the tension of the printed substrate X being conveyed, controls the dancer 12 according to the detected tension, and controls the tension of the printed substrate X being conveyed. is adjusted to an appropriate state.

The pretreatment section 2 is a part for forming an ink receiving layer on the printing substrate X, and includes a coater processing device 21 for applying an ink receiving liquid to the printing substrate X, and a coater processing device 21 for applying an ink receiving liquid to the printing substrate X. An IR dryer 22 for drying the printed base material X, an upstream base point roller 24 for guiding the printed base material Be prepared.
Note that, inside the preprocessing section 2, the upstream base point roller 24 is arranged on the rear side.
Further, switching of the conveyance path, which will be described later, is performed on the downstream side after the position where the printing substrate X is guided to the upstream base point roller 24.
In addition to these, the pre-processing unit 2 includes a corona treatment device 20 in the housing 2a for performing surface modification treatment on the printing substrate X, and a corona treatment device 20 for cooling and sending out the printing substrate X. It includes a cooling roller 23 and a nip roller 23a pressed against the circumferential surface of the cooling roller 23.
Note that in the preprocessing section 2, the cooling roller 23 serves as a driving roller.

In the pretreatment section 2, the corona treatment device 20 first performs a corona discharge treatment on the printing substrate X to modify the surface of the printing substrate X. As a result, the surface wettability of the printing base material X is improved.
Next, in the pre-processing section 2, the ink receiving liquid is applied to the printing substrate X by the coater processing device 21, the printing substrate X is dried by the IR dryer 22, and the printing substrate X is dried by the IR dryer 22. The ink-receiving liquid applied on top becomes an ink-receiving layer.
Note that the ink receiving layer is a layer that fixes the ink to the printing substrate X by receiving the applied ink.
Further, as for the composition of the ink-receiving layer, any conventionally known composition can be adopted as appropriate.
In the pretreatment section 2, the ink receiving layer is formed after the surface of the printing substrate X is modified, so that the adhesion between the printing substrate X and the ink receiving layer is improved.

Next, in the pre-processing section 2 , the printing substrate X is guided while being in contact with the cooling roller 23 .
As a result, the temperature of the printing substrate X whose temperature has increased in the IR dryer 22 is lowered.
Then, the upstream base point roller 24 guides the printing substrate X cooled by the cooling roller 23 from the pre-processing section 2 to the outside.

The first printing section 3 and the second printing section 4 are parts that print on the printing substrate X and dry it.
In the inkjet printing device 100 according to the first embodiment, of the two printing units arranged in series, the front side is the first printing unit 3 and the rear side is the second printing unit 4.
The first printing section 3 includes a first entrance roller 32 for guiding the printing substrate X into the inside of the first printing section 3, and a first entrance nip roller 32a that is pressed against the circumferential surface of the first entrance roller 32. , a print head 30 for applying ink to the printing substrate X, a drying section 31 for drying the printing substrate X to which the ink has been applied, and a printing section 3 for printing the printing substrate X. It includes a first exit roller 33 for guiding from the outside to the outside, a first exit nip roller 33a pressed against the circumferential surface of the first exit roller 33, and a housing 3a that accommodates these.
That is, the conveyance path from the first entrance roller 32 to the first exit roller 33 becomes the conveyance path in the first printing section 3. Further, the conveyance path in the first printing section 3 is common to a first conveyance path and a second conveyance path, which will be described later.
Note that the first inlet roller 32 and the first outlet roller 33 are both arranged on the front side of the print head 30 and the drying section 31. Moreover, the switching of the conveyance path, which will be described later, is performed upstream before the position where the printing substrate X is guided to the first entrance roller 32 and after the position where the printing substrate X is guided to the first exit roller 33. This is done downstream of the

In addition to this, the first printing unit 3 includes a feed roller 34 for sending out the printing target substrate X, a nip roller 34a pressed against the circumferential surface of the feed roller 34, and a print head 30 in the housing 3a. A CUE mark sensor 36 provided on the more upstream side, an automatic registration camera 38 provided on the more downstream side than the print head 30, and a tension detection device for detecting the tension of the printing substrate X in the first printing section 3. 37, a cooling roller 35 for cooling and feeding out the printing substrate X, and a nip roller 35a pressed against the circumferential surface of the cooling roller 35.
In the first printing section 3, the first entrance roller 32, feed roller 34, cooling roller 35, and first exit roller 33 serve as driving rollers.

In the first printing section 3 , the first entrance roller 32 guides the printing substrate X into the inside of the first printing section 3 .
The first entrance roller 32 and the first entrance nip roller 32a are installed at the entrance of the first printing section 3, and the feed roller 34 and the nip roller 34a are installed between the position where printing is performed by the print head 30 and the drying section 31. be done.
In the first printing section 3, the first inlet roller 32 and the first inlet nip roller 32a sandwich the printing target substrate X, and the first inlet roller 32 is rotationally driven by a drive motor (not shown), so that the printing target can be printed. The base material X is now sent out.
Further, the printing substrate X is sandwiched between the feed roller 34 and the nip roller 34a, and the printing substrate X is sent out by rotating the feeding roller 34 with a drive motor (not shown).
Further, in the first printing section 3, the tension detection device 37 detects the tension of the printing substrate X being conveyed, and the feed roller 34 is controlled according to the detected tension. Thereby, the tension of the printed substrate X being conveyed is adjusted to an appropriate state.

Inside the first printing section 3, a design image is printed by a print head 30.
When printing a design image by the print head 30, the CUE mark sensor 36 detects a mark printed in advance on the printing substrate X, sends a detection signal to a control section (not shown), and the control section receives the detection signal. The process starts when the printing base material X is conveyed by a preset conveyance distance from this timing.
Note that the conveyance distance of the printing substrate X is calculated by the control unit based on a measurement signal transmitted from an encoder (not shown) provided on an arbitrary roller.

Here, in the first printing section 3, the ink used for printing the design image by the print head 30 is a color ink containing dye or pigment, such as yellow ink (Y), magenta ink (M), and cyan ink (C). ) and black ink (K).
Note that the color ink is not limited to these (YMCK), and it is also possible to use compound inks containing these, glitter color inks that have been given glitter, metallic color inks that have a metallic feel, etc. .
Note that when the printing substrate X is a film for food packaging, these inks are preferably water-based from the viewpoint of safety.

In the first printing section 3, immediately after printing, the printing substrate X on which printing has been performed is photographed by an automatic registration camera 38, and the printing result is detected.
Then, the timing of printing the design image by the print head 30 is adjusted according to the printing result of the automatic registration camera 38, and the registration is adjusted.

In the first printing section 3, drying is then performed by a drying section 31.
The drying section 31 includes an IR dryer 31a and a hot air dryer 31b.
The printed substrate X on which printing has been performed is first dried by an IR dryer 31a, and then dried by a hot air dryer 31b while being guided along a spiral path.
Thereby, the ink adheres to the printing target substrate X, and it is possible to suppress color mixing during printing in the second printing section later.

Incidentally, if the printing substrate X is a soft film or the like and is likely to be damaged by deformation or the like due to high heat, it is preferable to dry it at the lowest possible temperature for a long time.
In the drying section 31 of the inkjet printing device according to the first embodiment, by using a spiral path, drying can be performed for a long time at a low temperature that does not damage the printing substrate X without increasing the size of the device. This makes it possible.

In the first printing section 3 , the dried printing target substrate X is guided while being in contact with a cooling roller 35 . Thereby, the temperature of the printing substrate X whose temperature has increased in the IR dryer 31a is lowered.
Then, the first exit roller 33 guides the printing substrate X cooled by the cooling roller 35 from the first printing section 3 to the outside.

The second printing section 4 includes a second entrance roller 42 for guiding the printing substrate X into the second printing section 4, and a second entrance nip roller 42a that is pressed against the circumferential surface of the second entrance roller 42. , a print head 40 for applying ink to the printing substrate X, a drying section 41 for drying the printing substrate X to which the ink has been applied, and a printing section 4 for printing the printing substrate X. It is provided with a second exit roller 43 for guiding it to the outside, a second exit nip roller 43a pressed against the circumferential surface of the second exit roller 43, and a casing 4a that accommodates these.
That is, the conveyance path from the second entrance roller 42 to the second exit roller 43 becomes the conveyance path in the second printing section 4.
Further, the conveyance path in the second printing section 4 is common to a first conveyance path and a second conveyance path, which will be described later.
Further, the drying section 41 includes an IR dryer 41a and a hot air dryer 41b.
Note that the second entrance roller 42 and the second exit roller 43 are both arranged on the front side of the print head 40 and the drying section 41. Moreover, the switching of the conveyance path, which will be described later, is performed upstream before the position where the printing substrate X is guided to the second entrance roller 42 and after the position where the printing substrate X is guided to the second exit roller 43. This is done downstream of the

In addition to this, the second printing unit 4 includes a feed roller 44 for sending out the printing target base material A CUE mark sensor 46 provided on the upstream side, an automatic registration camera 48 provided on the downstream side of the print head 40, a cooling roller 45 for cooling and sending out the printing substrate X, and and a nip roller 45a pressed against the peripheral surface.
In the second printing section 4, the second entrance roller 42, feed roller 44, cooling roller 45, and second exit roller 43 serve as drive rollers.
Here, the drying section 41, CUE mark sensor 46, automatic registration camera 48, and cooling roller 45 in the second printing section 4 are the same as the drying section 31, CUE mark sensor 36, automatic registration camera 38, and cooling roller 45 in the first printing section 3. Since they each have the same configuration as the cooling roller 35, duplicate explanations will be omitted.

In the second printing section 4 , the second entrance roller 42 guides the printing substrate X into the second printing section 4 .
The second entrance roller 42 and the second entrance nip roller 42a are installed at the entrance of the second printing section 4, and the feed roller 44 and the nip roller 44a are installed between the position where printing is performed by the print head 40 and the drying section 41. be done.
In the second printing section 4, the second entrance roller 42 and the second entrance nip roller 42a sandwich the printing target substrate X, and the second entrance roller 42 is rotationally driven by a drive motor (not shown), so that the printing target can be printed. The base material X is now sent out.
Further, the printing substrate X is held between the feed roller 44 and the nip roller 44a, and the printing substrate X is sent out by rotating the feeding roller 44 with a drive motor (not shown).

Inside the second printing section 4, a background image is printed by the print head 40.
In the second printing section 4, the ink used for printing the background image by the print head 40 is white ink (W) containing dye or pigment.
In addition, when the printing substrate X is a film for food packaging, from the viewpoint of safety, it is preferable that the white ink is water-based.

Therefore, in the inkjet printing device 100, when printing is performed in the order of the first printing section 3 and the second printing section 4, the design image and the background image are printed on the surface of the printing substrate X in this order. Therefore, when printing is performed in the order of the second printing section 4 and the first printing section 3, the background image and the design image are printed on the surface of the printing substrate X in this order.
That is, as will be described later, by changing the conveyance path of the printing substrate X, it becomes possible to print on the front side and on the back side.

The post-processing section 5 is a part for forming an overcoat layer on the printing substrate X, and includes a downstream base point roller 54 for guiding the printing substrate X into the inside of the post-processing section 5, and a downstream side A downstream base point nip roller 54a pressed against the circumferential surface of the base roller 54, a coater processing device 51 for applying an overcoat liquid to the printing substrate X, and a printing substrate X to which the overcoat liquid has been applied. It includes an IR dryer 52 for drying and a housing 5a that houses them.
Note that, inside the post-processing section 5, the downstream base point roller 54 is arranged on the front side.
Further, switching of the conveyance path, which will be described later, is performed on the upstream side before the position where the printing substrate X is guided to the downstream base point roller 54.
In addition to these, the post-processing section 5 includes a cooling roller 53 for cooling and feeding out the printing substrate X, and a nip roller 53a pressed against the circumferential surface of the cooling roller 53, in the housing 5a. .
Note that in the post-processing section 5, the downstream base point roller 54 and the cooling roller 53 serve as drive rollers.

In the post-processing section 5, the overcoat liquid is applied to the printing substrate X by the coater processing device 51, the printing substrate X is dried by the IR dryer 52, and the overcoating liquid is applied onto the printing substrate X. The resulting overcoat liquid becomes an overcoat layer.
Note that the overcoat layer is a transparent layer for protecting the printed surface.
Further, as for the composition of the overcoat layer, conventionally known compositions can be appropriately adopted.
Next, in the post-processing section 5 , the printing substrate X is guided while being in contact with a cooling roller 53 . As a result, the temperature of the printing substrate X whose temperature has increased in the IR dryer 52 is lowered.

The image reading unit 7 is a part that reads an image consisting of a printed design image and a background image.
The image data read by the image reading unit 7 is transmitted to a control device (not shown), and the control device determines the color tone, the presence or absence of a shift in the printing position, etc. Note that if there is a problem, the timing of printing, etc. will be adjusted accordingly.

The discharge section 6 is a part for collecting the printed substrate X, and includes a feed roller 61 for feeding the printed substrate X, a nip roller 61a pressed against the circumferential surface of the feed roller 61, It includes a winding shaft 60 for winding up the printing base material X, and a housing 6a that accommodates these.
In addition to these, the discharge section 6 includes a dancer 62 for adjusting the tension of the printing substrate X.
Note that in the discharge section 6, the feed roller 61 is a driving roller.

In the discharge section 6, the printing substrate X is held between the feed roller 61 and the nip roller 61a, and the printing substrate X is rolled onto the winding shaft 60 by rotating the feeding roller 61 with a drive motor (not shown). It is designed to be sent. The winding shaft 60 is rotationally driven by a drive motor (not shown), and winds up the printing base material X.
At this time, in the discharge section 6, the tension of the printing substrate X to be wound up is adjusted to an appropriate state by adjusting the dancer 62, so that the printing substrate X is maintained at an appropriate tension. It will be wound up on the winding shaft 60.

In the inkjet printing device 100, the preprocessing section 2 and the first printing section 3 are connected via a communication section C1.
A first work space S1 is provided above the communication section C1 between the preprocessing section 2 and the first printing section 3.
The first work space S1 has a width in the front-rear direction that allows the operator to enter, and allows the worker to step on the communication section C1 and perform switching operations.

Similarly, the first printing section 3 and the second printing section 4 are communicated via a communication section C2.
A second work space S2 is provided above the communication section C2 between the first printing section 3 and the second printing section 4.
The second work space S2 has a width in the front-rear direction that allows the operator to enter, and allows the operator to step on the communication part C2 and perform switching operations.
Further, the second printing section 4 and the post-processing section 5 are communicated via a communication section C3.
A third work space S3 is provided above the communication section C3 between the second printing section 4 and the post-processing section 5.
The third work space S3 has a width in the front-rear direction that allows the operator to enter, and allows the worker to step on the communication part C3 and perform switching operations.
Due to these, in the inkjet printing apparatus 100, the work of switching the conveyance path is facilitated.

Here, the sizes of the first work space S1, the second work space S2, and the third work space S3 are preferably such that the width in the front and back direction is 600 to 1200 mm, and the height is 600 to 1200 mm, respectively, from the viewpoint of workability. The length is preferably 1800 to 2000 mm.
Note that the sizes of the first work space S1, the second work space S2, and the third work space S3 may be the same or different.

Next, the conveyance route will be explained.
In the inkjet printing device 100 according to the first embodiment, there is a first conveyance path R1 in which printing is performed on one side of the printing substrate X in the order of the first printing section 3 and the second printing section 4, and the second printing section R1. It has a second conveyance path R2 in which printing is performed in the order of the printing section 4 and the first printing section 3.
That is, the order of color ink printing in the first printing section 3 and white ink printing in the second printing section 4 is reversed between the first conveyance path R1 and the second conveyance path R2.

FIG. 2 is a partial side view for explaining the first conveyance path in the inkjet printing device according to the first embodiment, and FIG. 3 is a partial side view for explaining the second conveyance path in the inkjet printing device according to the first embodiment. FIG. Note that the conveyance path before the preprocessing section 2 and the conveyance path after the second printing section 4 are as shown in FIG. 1, and are common to the first conveyance path R1 and the second conveyance path R2. Therefore, it is omitted in FIGS. 2 and 3.

As shown in FIG. 2, in the first conveyance path R1, the printing substrate X that has been sent out from the supply section 1 and passed through the pretreatment section 2 heads downward from the upstream base point roller 24 of the pretreatment section 2. After passing through the interior of the communication section C1 below the first working space S1, the paper heads upward and is conveyed to the first entrance roller 32 of the first printing section 3.

Next, it enters the inside of the first printing section 3 through the first entrance roller 32, and the print head 30 of the first printing section 3 prints a design image, and the drying section 31 performs drying. It is conveyed to the outside of the first printing section 3 from the first exit roller 33 of the first printing section 3 .
Next, it heads downward from the first exit roller 33, passes below the drying section 31 of the first printing section 3, passes through the inside of the communication section C2 under the second working space section S2, and then moves upward. , and is conveyed to the second inlet roller 42 of the second printing section 4.

Next, it enters the second printing section 4 through the second entrance roller 42, and the printing head 40 of the second printing section 4 prints a background image, and the drying section 41 performs drying. It is conveyed to the outside of the second printing section 4 from the second exit roller 43 of the second printing section 4 .
Next, it heads downward from the second exit roller 43, passes below the drying section 41 of the second printing section 4, passes through the inside of the communication section C3 under the third work space section S3, and then passes through the post-processing section. 5 to the downstream base point roller 54 (see FIG. 1).

Then, after passing through the post-processing section 5, it is transported to the discharge section 6.
Therefore, according to the first conveyance path R1, it is possible to perform back printing in which the design image and the background image are printed in this order.
In addition, in the first conveyance path R1, other than the upstream base point roller 24, the first entrance roller 32, the first exit roller 33, the second entrance roller 42, the second exit roller 43, and the downstream base point roller 54 are also necessary. Accordingly, rollers for guiding the printing target substrate X are arranged at appropriate locations.

As shown in FIG. 3, in the second conveyance path R2, the printing substrate X that has been sent out from the supply section 1 and passed through the pretreatment section 2 heads upward from the upstream base point roller 24 of the pretreatment section 2. It passes above the first working space S1, passes above the print head 30 of the first printing section 3, passes above the second working space S2, and then heads downward to the second printing section 4. It is conveyed to the first entrance roller 42.

Next, it enters the second printing section 4 through the second entrance roller 42, and the printing head 40 of the second printing section 4 prints a background image, and the drying section 41 performs drying. It is conveyed to the outside of the second printing section 4 from the second exit roller 43 of the second printing section 4 .
Next, it heads downward from the second exit roller 43 and passes through the inside of the communication section C2 below the second working space section S2, and then heads upward and passes above the print head 30 of the first printing section 3. Thereafter, the paper is conveyed downward to the first entrance roller 32 of the first printing section 3 .

Next, it enters the inside of the first printing section 3 through the first entrance roller 32, and the print head 30 of the first printing section 3 prints a design image, and the drying section 31 performs drying. It is conveyed to the outside of the first printing section 3 from the first exit roller 33 of the first printing section 3 .
Next, it heads downward from the first exit roller 33, passes below the drying section 31 of the first printing section 3, passes through the inside of the communication section C2 under the second working space section S2, and passes through the second printing section After passing under the drying section 41 of No. 4 and inside the communication section C3 below the third working space section S3, it is conveyed to the downstream base point roller 54 of the post-processing section 5 (see FIG. 1).

Then, after passing through the post-processing section 5, it is transported to the discharge section 6.
Therefore, according to the second conveyance path R2, it is possible to perform surface printing in which the background image and the design image are printed in this order.
In addition, in the second conveyance path R2, in addition to the upstream base point roller 24, the first entrance roller 32, the first exit roller 33, the second entrance roller 42, the second exit roller 43, and the downstream base point roller 54, there are also necessary rollers. Accordingly, rollers for guiding the printing target substrate X are arranged at appropriate locations.

FIG. 4 is a principle diagram for explaining switching between the first conveyance path and the second conveyance path in the inkjet printing apparatus according to the first embodiment.
Note that in the inkjet printing device according to the first embodiment, the first printing section 3 and the second printing section 4 are arranged in series (see FIG. 1), but in FIG. 4, they are arranged in parallel for convenience. I will explain.
Further, in FIG. 4, the first transport route R1 is shown by a solid line, and the second transport route R2 is shown by a broken line.
As shown in FIG. 4, the first conveyance path R1 and the second conveyance path R2 include a conveyance path from the supply section 1 to the upstream base point roller 24, a conveyance path inside the first printing section 3, and a conveyance path inside the second printing section 4. The internal conveyance path and the conveyance path from the downstream base point roller 54 to the discharge section 6 are common.

On the other hand, in the first conveyance path R1, the printing substrate X is conveyed from the upstream base roller 24 to the first entrance roller 32, conveyed from the first exit roller 33 to the second entrance roller 42, and then The printing substrate X is transported from the exit roller 43 to the downstream base roller 54, and in the second transport path R2, the printing substrate They differ in that they are transported to the first entrance roller 32 and transported from the first exit roller 33 to the downstream base roller 54 .

Therefore, for example, when switching from the first conveyance path R1 to the second conveyance path R2, the conveyance destination of the printing substrate X from the upstream base roller 24 is switched from the first entrance roller 32 to the second entrance roller 42. , the conveyance source of the printing target substrate X up to the downstream base point roller 54 is switched from the second exit roller 43 to the first exit roller 33, and the printing target substrate X that was transported from the first exit roller 33 to the second entrance roller 42 is changed. What is necessary is just to switch so that the base material X is conveyed from the 2nd exit roller 43 to the 1st entrance roller 32.
At this time, the upstream base point roller 24 and the roller upstream of the second entrance roller 42 have different passing surfaces for the printing substrate X, respectively.
Note that these switching may be performed by replacing the printing substrate X itself, or by cutting and connecting the printing substrate X.
Moreover, when switching from the second conveyance route R2 to the first conveyance route R1, this is reversed.

Returning to FIGS. 1, 2, and 3, in the inkjet printing device 100, the downstream base roller 54, the first entrance roller 32, the first exit roller 33, the second entrance roller 42, and the second exit roller 43 include: A gripping means for gripping the printing target base material X is attached.
In the downstream base roller 54, a downstream base nip roller 54a is pressed against the peripheral surface of the downstream base roller 54 as a gripping means. The downstream base point roller 54 and the downstream base nip roller 54a not only guide the printing substrate X into the post-processing section 5, but also can grip and fix the stationary printing substrate X at that position. It has become.

In the first entrance roller 32, the first entrance nip roller 32a described above corresponds to the gripping means. The first entrance roller 32 and the first entrance nip roller 32a are capable of not only feeding out the printing substrate X, but also gripping and fixing the stationary printing substrate X at that position.
Further, in the first exit roller 33, the above-described first exit nip roller 33a corresponds to the gripping means. The first exit roller 33 and the first exit nip roller 33a not only guide the printing substrate X from the first printing section 3 to the outside, but also can grip and fix the stationary printing substrate X at that position. It becomes.

In the second entrance roller 42, the second entrance nip roller 42a described above corresponds to the gripping means. The second entrance roller 42 and the second entrance nip roller 42a are capable of not only feeding out the printing substrate X, but also gripping and fixing the stationary printing substrate X at that position.
Further, in the second exit roller 43, the second exit nip roller 43a described above corresponds to a gripping means. The second exit roller 43 and the second exit nip roller 43a not only guide the printing substrate X from the second printing section 4 to the outside, but also can grip and fix the stationary printing substrate X at that position. It becomes.

Due to these, in the inkjet printing device 100, when switching the printing substrate X, the printing substrate Since the entrance roller 42 and the second exit roller 43 can temporarily hold and fix the sheet, it is possible to more easily switch the conveyance path.
Note that it is preferable that at least the first entrance roller 32, the first exit roller 33, the second entrance roller 42, and the second exit roller 43 be provided with gripping means for gripping the printing target substrate.

In the inkjet printing apparatus 100 according to the first embodiment, it is the unused transport route among the first transport route R1 and the second transport route R2, and overlaps with the first transport route R1 and the second transport route R2. An unused printing substrate is placed on the conveyance path that is not used.
The inkjet printing apparatus 100 according to the first embodiment includes a first unused printing substrate X1, a second unused printing substrate X2, and a third unused printing substrate X3.
With this, when switching the conveyance path, you can simply cut the printing substrate X on the original conveyance path at a predetermined position and connect the end of the cut substrate with the end of the unused printing substrate. Since the printing substrate to be used can be set as the printing substrate X and placed on a new conveyance path, it becomes possible to perform the work of switching the conveyance path even more easily.
Note that among the ends of the unused printing substrate, the end on the upstream side in the conveyance path is referred to as the upstream end, and the end on the downstream side is referred to as the downstream end.

Specifically, for example, in the first conveyance path R1 shown in FIG. and is located above the upstream base point roller 24, the downstream end X12 is upstream of the second entrance roller 42 in the second conveyance path R2, and is located near the second entrance roller 42. positioned.
Then, the first unused printing substrate X1 passes from the upstream end X11 above the first work space S1, passes above the print head 30 of the first printing section 3, and is then used for the second work. After passing over the space S2, it heads downward and extends to the downstream end X12.

As a result, when switching from the first conveyance path R1 to the second conveyance path R2, the printing substrate X connected from the upstream base roller 24 to the first entrance roller 32 is changed to , and cut near the upstream base point roller 24, and connect the printing substrate X upstream from the cutting position to the upstream end X11 of the first unused printing substrate X1, and the first outlet The printing substrate X connected from the roller 33 to the second entrance roller 42 is cut at the upstream side of the second entrance roller 42 in the first conveyance path R1 and near the second entrance roller 42, and then By connecting the printing substrate X on the downstream side of the cutting position to the downstream end X12 of the first unused printing substrate X1, the printing substrate X is transferred from the pretreatment section 2 to the first printing section 3. can be easily switched to the path of the printing substrate X from the pre-processing section 2 to the second printing section 4.

Further, in the first conveyance path R1 shown in FIG. 2, the upstream end X21 of the second unused printing substrate X2 is downstream of the second exit roller 43 in the second conveyance path R2, and It is located at the rear lower P on the second work space S2 side of the first printing section 3, the downstream end X22 is upstream of the first entrance roller 32 in the second conveyance path R2, and the first entrance It is located near the roller 32.
The second unused printing substrate X2 then heads upward from the upstream end X21, passes above the print head 30 of the first printing section 3, and then heads downward to the downstream end X22. It is extending.

As a result, when switching from the first conveyance path R1 to the second conveyance path R2, the printing substrate X connected from the second exit roller 43 to the downstream base point roller 54 is transferred to the second exit roller in the first conveyance path R1. 43 and near the second exit roller 43, and connect the printing substrate X upstream from the cutting position to the upstream end X21 of the second unused printing substrate X2. At the same time, the printing base material By cutting near the first entrance roller 32 and connecting the printing substrate X downstream from the cutting position to the downstream end X22 of the second unused printing substrate X2, the preprocessing section 2 The path of the printing substrate X to the first printing section 3 and the path of the printing substrate X from the second printing section 4 to the post-processing section 5 are changed from the second printing section 4 to the first printing section 3 It is possible to easily switch to the path of the printing base material X.

In the second conveyance path R2 shown in FIG. 3, the third unused printing substrate X3 has an upstream end X31 downstream of the upstream base point roller 24 in the first conveyance path R1, and It is located near the base point roller 24, and the downstream end X32 is located upstream of and near the first entrance roller 32 in the first conveyance path R1.
Then, the third unused printing substrate X3 heads downward from the upstream end X31, passes through the inside of the communication section C1 below the first work space S1, and then heads upward to the downstream end. It extends to section X32.

As a result, when switching from the second conveyance path R2 to the first conveyance path R1, the printing substrate X connected from the upstream base point roller 24 to the second entrance roller 42 is transferred to the upstream base point roller 24 and near the upstream base point roller 24, and connect the printing substrate X upstream from the cutting position to the upstream end X31 of the third unused printing substrate X3. At the same time, the printing base material By cutting in the vicinity and connecting the printing substrate X on the downstream side of the cutting position to the downstream end X32 of the third unused printing substrate X3, from the pre-processing section 2 to the second printing section 4. The path of the printing substrate X from the second printing section 4 to the first printing section 3 is the path of the printing substrate X from the pretreatment section 2 to the first printing section 3. can be easily switched to.

In the inkjet printing device 100 according to the first embodiment, the rollers (end rollers) located at both ends of the unused printing substrates X1, X2, X3 are connected to the corresponding unused printing substrates X1, X2, X3. A retaining means is attached for retaining the.
In the first unused printing substrate X1 shown in FIG. 2, a first upstream end nip roller 71a as a holding means is pressed against the circumferential surface of the first upstream end roller 71 located at the upstream end X11. A first downstream end nip roller 72a as a holding means is pressed against the circumferential surface of the first downstream end roller 72 located at the downstream end X12.
The first upstream end roller 71 and the first upstream end nip roller 71a are capable of holding the stationary upstream end X11 of the first unused printing substrate X1 at that position, The first downstream end roller 72 and the first downstream end nip roller 72a are capable of holding the stationary downstream end X12 of the first unused printing substrate X1 at that position.

In addition, in the second unused printing substrate X2, a second upstream end nip roller 73a as a holding means is pressed against the circumferential surface of the second upstream end roller 73 located at the upstream end X21. A second downstream end nip roller 74a as a holding means is pressed against the circumferential surface of the second downstream end roller 74 located at the downstream end X22.
The second upstream end roller 73 and the second upstream end nip roller 73a are capable of holding the stationary upstream end X21 of the second unused printing substrate X2 at that position. The second downstream end roller 74 and the second downstream end nip roller 74a are capable of holding the stationary downstream end X22 of the second unused printing substrate X2 at that position.

Similarly, in the third unused printing base material X3 shown in FIG. 75a is pressed against the circumferential surface of the third downstream end roller 76 located at the downstream end X32, and a third downstream end nip roller 76a is pressed as a holding means.
The third upstream end roller 75 and the third upstream end nip roller 75a are capable of holding the stationary upstream end X31 of the third unused printing substrate X3 at that position. The third downstream end roller 76 and the third downstream end nip roller 76a are capable of holding the stationary downstream end X32 of the third unused printing substrate X3 at that position.

Due to these, in the inkjet printing apparatus 100 according to the first embodiment, both ends of the unused printing substrates X1, X2, and X3 can be temporarily held, so that the unused printing substrates X1, When X2 and X3 are not in use, they can be prevented from falling, and when switching the transport route, the work can be performed more easily.

As described above, in the inkjet printing apparatus 100, for example, a soft film for food packaging is used as the printing substrate X, and the soft film is passed through the first conveyance path R1 to perform printing, etc., thereby performing back printing. A printed matter is obtained, and the soft film is passed through the second conveyance path R2 to perform printing, etc., thereby obtaining a front printed matter.

FIG. 5(a) is a schematic cross-sectional view showing a printed matter for back printing for food packaging manufactured using the inkjet printing apparatus according to the first embodiment, and FIG. FIG. 2 is a schematic cross-sectional view showing a front printed matter for food packaging manufactured using the inkjet printing device according to the present invention.
Note that in FIGS. 5A and 5B, for the sake of explanation, the design image A11 and the background image A12 are shown as having a constant thickness.
As shown in (a) of FIG. 5, a back-printed printed matter 101 includes a printing substrate X made of a transparent or translucent soft film, and an ink receiving layer laminated on the back surface of the printing substrate X. A1, a design image A11 provided on the back surface of the ink receiving layer A1, a background image A12 provided on the back surface of the design image A11, and an overcoat layer A2 laminated on the back surface of the background image A12. Be prepared.
In the back-printed printed matter 101, a design image A11 and a background image A12 are drawn in this order on the back surface of the ink-receiving layer A1, and the background image A12 is drawn so as to cover the design image A11.
Therefore, in the back-printed printed matter 101, the design image A11 is visible from the printing substrate X side.

Further, as shown in FIG. 5(b), the front printed matter 102 includes a printing substrate X made of a transparent or translucent soft film, and an ink layered on the surface of the printing substrate X. A receiving layer B1, a background picture B12 provided on the surface of the ink receiving layer B1, a design picture B11 provided on the surface of the background picture B12, and a transparent or translucent layer laminated on the surface of the design picture B11. overcoat layer B2.
In the front printed matter 102, a background image B12 and a design image B11 are drawn in this order on the surface of the ink receiving layer B1, and the design image B11 is drawn so as to overlap the background image B12.
Therefore, in the front printed matter 102, the design image B11 is visible from the overcoat layer B2 side.

In this manner, by using the inkjet printing apparatus 100, it is possible to produce a back-printed printed matter 101 and a front-printed printed matter 102.
Furthermore, by using the inkjet printing device 100, it is possible to suppress the occurrence of color mixture.

(Second embodiment)
Next, an inkjet printing device according to a second embodiment will be described.
The inkjet printing device according to the second embodiment, similarly to the inkjet printing device 100 according to the first embodiment, includes a supply section for supplying a printing substrate, and a supply section for forming an ink receiving layer on the printing substrate. a first printing section and a second printing section for printing and drying the printing substrate, a post-processing section for forming an overcoat layer on the printing substrate, and a printed image. The apparatus includes an image reading section for reading the image, and a discharging section for collecting the printed substrate.
In such an inkjet printing device, a supply section, a pre-processing section, a first printing section, a second printing section, a post-processing section, an image reading section, and a discharge section are arranged in series in this order.
Note that the inkjet printing device according to the second embodiment is the same as the inkjet printing device 100 according to the first embodiment, except that the specific conveyance route and the position of the unused printing substrate are different accordingly. Therefore, common explanations will be omitted.

FIG. 6 is a partial side view for explaining the first conveyance path in the inkjet printing device according to the second embodiment, and FIG. 7 is a partial side view for explaining the second conveyance path in the inkjet printing device according to the second embodiment. FIG.
Note that the conveyance path before the preprocessing section 2 and the conveyance path after the second printing section are as shown in FIG. 1, and since the first conveyance path and the second conveyance path are common, 6 and FIG. 7 are omitted.

As shown in FIG. 6, in the first conveyance path R1a, the printing substrate X sent out from the supply section 1 and passed through the pre-processing section 2 heads upward from the upstream base point roller 24 of the pre-processing section 2. After passing above the first work space S1, the paper heads downward and is conveyed to the first entrance roller 32 of the first printing section 3.

Next, it enters the inside of the first printing section 3 through the first entrance roller 32, and the print head 30 of the first printing section 3 prints a design image, and the drying section 31 performs drying. It is conveyed to the outside of the first printing section 3 from the first exit roller 33 of the first printing section 3 .
Next, it heads downward from the first exit roller 33 and passes below the drying section 31 of the first printing section 3, then heads upward behind the drying section 31 and passes above the second working space S2. Thereafter, the paper is conveyed downward to the second entrance roller 42 of the second printing section 4 .

Next, it enters the second printing section 4 through the second entrance roller 42, and the printing head 40 of the second printing section 4 prints a background image, and the drying section 41 performs drying. It is conveyed to the outside of the second printing section 4 from the second exit roller 43 of the second printing section 4 .
Next, it heads downward from the second exit roller 43, passes below the drying section 41 of the second printing section 4, passes through the inside of the communication section C3 under the third work space section S3, and then passes through the post-processing section. It is conveyed to the downstream base point roller 54 of No. 5.

Then, after passing through the post-processing section 5, it is transported to the discharge section 6.
Therefore, according to the first conveyance path R1a, it is possible to perform back printing in which the design image and the background image are printed in this order.
In addition, in the first conveyance path R1a, other than the upstream base point roller 24, the first entrance roller 32, the first exit roller 33, the second entrance roller 42, the second exit roller 43, and the downstream base point roller 54 are also necessary. Accordingly, rollers for guiding the printing target substrate X are arranged at appropriate locations.

As shown in FIG. 7, in the second conveyance path R2a, the printing substrate X sent out from the supply section 1 and passed through the pretreatment section 2 heads upward from the upstream base point roller 24 of the pretreatment section 2. It passes above the first working space S1, passes above the print head 30 of the first printing section 3, passes above the second working space S2, and then heads downward to the second printing section 4. It is conveyed to the first entrance roller 42.

Next, it enters the second printing section 4 through the second entrance roller 42, and the printing head 40 of the second printing section 4 prints a background image, and the drying section 41 performs drying. It is conveyed to the outside of the second printing section 4 from the second exit roller 43 of the second printing section 4 .
Next, it heads upward from the second exit roller 43, passes above the second working space S2, passes above the print head 30 of the first printing section 3, and then heads downward, passing above the second working space S2, passing above the print head 30 of the first printing section 3, and then heading downward, passing above the second working space S2. It is conveyed to the first entrance roller 32.

Next, it enters the inside of the first printing section 3 through the first entrance roller 32, and the print head 30 of the first printing section 3 prints a design image, and the drying section 31 performs drying. It is conveyed to the outside of the first printing section 3 from the first exit roller 33 of the first printing section 3 .
Next, it heads downward from the first exit roller 33 and passes below the drying section 31 of the first printing section 3, then heads upward behind the drying section 31 and passes above the second working space S2. After that, it heads downward, passes below the drying section 41 in front of the drying section 41 of the second printing section 4, and passes through the inside of the communication section C3 under the third working space section S3. It is conveyed to the downstream base point roller 54 of the post-processing section 5 .

Then, after passing through the post-processing section 5, it is transported to the discharge section 6.
Therefore, according to the second conveyance path R2a, it is possible to perform surface printing in which the background image and the design image are printed in this order.
In addition, in the second conveyance path R2a, in addition to the upstream base roller 24, the first entrance roller 32, the first exit roller 33, the second entrance roller 42, the second exit roller 43, and the downstream base roller 54, there are also necessary rollers. Accordingly, rollers for guiding the printing target substrate X are arranged at appropriate locations.

In this way, in the inkjet printing device according to the second embodiment, the first conveyance path R1a and the second conveyance path R2a always pass above the first work space S1 and the second work space S2. It is set in. In this case, it is possible to prevent dust generated by people entering and leaving the first work space S1 and the second work space S2 from adhering to the printing substrate X being transported along the transport path as much as possible.
Here, the height of the first conveyance path R1a and the second conveyance path R2a is preferably at least 1000 mm or more from the ground, and more preferably 1800 mm or more from the ground, from the viewpoint of the amount of dust thrown up. preferable.

In the inkjet printing device according to the second embodiment, the transport route is the one that is not used between the first transport route R1a and the second transport route R2a, and the first transport route R1a and the second transport route R2a do not overlap. An unused printing substrate is placed on the conveyance path.
The inkjet printing device according to the second embodiment includes a first unused printing substrate X1a, a second unused printing substrate X2a, and a third unused printing substrate X3a.
With this, when switching the conveyance path, you can simply cut the printing substrate X on the original conveyance path at a predetermined position and connect the end of the cut substrate with the end of the unused printing substrate. Since the printing substrate to be used can be set as the printing substrate X and placed on a new conveyance path, it becomes possible to perform the work of switching the conveyance path even more easily.

Specifically, for example, in the first conveyance path R1a shown in FIG. and is located above the print head 30 of the first printing section 3, and the downstream end X1a2 is upstream of the second entrance roller 42 in the second conveyance path R2a, and It is located above 42.
The first unused printing substrate X1a extends from the upstream end X1a1, passes above the print head 30 and the second work space S2, and extends to the downstream end X1a2.

As a result, when switching from the first conveyance path R1a to the second conveyance path R2a, the printing substrate X connected from the upstream base point roller 24 to the first entrance roller 32 is transferred to the first entrance roller in the first conveyance path R1a. 32 and near the first entrance roller 32, and connect the printing substrate X upstream from the cutting position to the upstream end X1a1 of the first unused printing substrate X1a. At the same time, the printing substrate X, which is connected from the first exit roller 33 to the second entrance roller 42, is placed on the upstream side of the second entrance roller 42 in the first conveyance path R1a, and From the pre-processing section 2 to the first printing section 3 by cutting in the vicinity and connecting the printing substrate X downstream from the cutting position to the downstream end X1a2 of the first unused printing substrate X1a. The path of the printing substrate X can be easily switched to the path of the printing substrate X from the pretreatment section 2 to the second printing section 4.

Further, in the first conveyance path R1a shown in FIG. 6, the upstream end X2a1 of the second unused printing substrate X2a is downstream of the second exit roller 43 in the second conveyance path R2a, and Located above the second exit roller 43, the downstream end X2a2 is upstream of the first entrance roller 32 in the second conveyance path R2a, and is located above the print head 30 of the first printing section 3. are doing.
The second unused printing substrate X2a passes from the upstream end X2a1, passes above the second work space S2, and extends to the downstream end X2a2.
Note that the first unused printing substrate X1a and the second unused printing substrate X2a are substantially parallel, and the first unused printing substrate X1a is closer to the second unused printing substrate X2a. is also located above.

As a result, when switching from the first conveyance path R1a to the second conveyance path R2a, the printing substrate X connected from the second exit roller 43 to the downstream base point roller 54 is transferred to the second exit roller in the first conveyance path R1a. 43 and near the second exit roller 43, and connect the printing substrate X upstream from the cutting position to the upstream end X2a1 of the second unused printing substrate X2a. At the same time, the printing substrate X on the downstream side of the cut position of the printing substrate X cut near the first entrance roller 32 described above is connected to the downstream end X2a2 of the second unused printing substrate X2a. By doing so, the path of the substrate X to be printed from the pre-processing section 2 to the first printing section 3 and the path of the substrate X to be printed from the second printing section 4 to the post-processing section 5 can be changed to the second printing section 4. It is possible to easily switch the path of the printing target substrate X from the first printing section 3 to the first printing section 3.

Further, in the first conveyance path R1a shown in FIG. 6, the upstream end X3a1 of the third unused printing substrate X3a is downstream of the first exit roller 33 in the second conveyance path R2a, and It is located in front of the second entrance roller 42 in the second printing section 4, the downstream end X3a2 is upstream of the downstream base point roller 54 in the second conveyance path R2a, and inside the second printing section 4. It is located in front of the second exit roller 43 of.
The third unused printing substrate X3a extends downward from the upstream end X3a1 to the downstream end X3a2.

As a result, when switching from the first conveyance path R1a to the second conveyance path R2a, the printing substrate X on the upstream side of the cutting position of the printing substrate X cut near the second entrance roller 42 is transferred to The printing substrate X that is connected to the upstream end X3a1 of the unused printing substrate X3a and downstream of the cut position of the printing substrate X cut near the above-mentioned second exit roller 43 is connected to the third By connecting to the downstream end X3a2 of the unused printing substrate X3a, the path of the printing substrate X from the first printing section 3 to the second printing section 4 and from the second printing section 4 to the post-processing section 5 are The path of the substrate X to be printed can be easily switched to the path of the substrate X to be printed from the first printing section to the post-processing section 5.

In the inkjet printing device according to the second embodiment, the rollers (end rollers) located at both ends of the unused printing substrates X1a, X2a, X3a are connected to the corresponding unused printing substrates X1a, X2a, X3a. A retaining means is attached for retaining.
In the first unused printing substrate X1a shown in FIG. 6, a first upstream end nip roller 81a as a holding means is pressed against the circumferential surface of the first upstream end roller 81 located at the upstream end X1a1. A first downstream end nip roller 82a as a holding means is pressed against the circumferential surface of the first downstream end roller 82 located at the downstream end X1a2.
The first upstream end roller 81 and the first upstream end nip roller 81a are capable of holding the stationary upstream end X1a1 of the first unused printing substrate X1a at that position, The first downstream end roller 82 and the first downstream end nip roller 82a are capable of holding the stationary downstream end X1a2 of the first unused printing substrate X1a at that position.

In addition, in the second unused printing substrate X2a, a second upstream end nip roller 83a as a holding means is pressed against the circumferential surface of the second upstream end roller 83 located at the upstream end X2a1. A second downstream end nip roller 84a as a holding means is pressed against the circumferential surface of the second downstream end roller 84 located at the downstream end X2a2.
The second upstream end roller 83 and the second upstream end nip roller 83a are capable of holding the stationary upstream end X2a1 of the second unused printing substrate X2a at that position. The second downstream end roller 84 and the second downstream end nip roller 84a are capable of holding the stationary downstream end X2a2 of the second unused printing base material X2a at that position.

Further, in the third unused printing substrate X3a, a third upstream end nip roller 85a is pressed as a holding means to the circumferential surface of the third upstream end roller 85 located at the upstream end X3a1. A third downstream end nip roller 86a is pressed as a holding means to the circumferential surface of the third downstream end roller 86 located at the downstream end X3a2.
The third upstream end roller 85 and the third upstream end nip roller 85a are capable of holding the stationary upstream end X3a1 of the third unused printing substrate X3a at that position, The third downstream end roller 86 and the third downstream end nip roller 86a are capable of holding the stationary downstream end X3a2 of the third unused printing substrate X3a at that position.

Due to these, in the inkjet printing apparatus according to the second embodiment, both ends of the unused printing substrates X1a, X2a, X3a can be temporarily held, so that the unused printing substrates X1a, X2a .

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments.

The inkjet printing device according to this embodiment includes a supply section 1, a pre-processing section 2, a first printing section 3, a second printing section 4, a post-processing section 5, an image reading section 7, and a discharge section 6. The preprocessing section 2, the postprocessing section 5, and the image reading section 7 are not essential components.
Further, in addition to the first printing section 3 and the second printing section 4, a printing section may be provided.

In the inkjet printing device according to the present embodiment, the supply unit 1 adopts a method of pulling out the printing target substrate X from the state wound around the supply shaft 10, but if the printing target substrate X can be supplied. However, it is not limited to this.
Further, the supply unit 1 includes a meandering prevention device 11, a dancer 12, a tension detection device 14, etc., but these are not essential components.

In the inkjet printing apparatus according to this embodiment, the pre-processing section 2 includes a corona treatment device 20, a cooling roller 23, an upstream base point roller 24, etc., but these are not essential components.
Note that when the preprocessing section 2 does not have the upstream base point roller 24, the upstream base point roller 24 is provided on the conveyance path between the supply section 1 and the first printing section 3, and when the preprocessing section 2 does not have the upstream base point roller 24 , the upstream base point roller 24 is provided on the conveyance path between the preprocessing section 2 and the first printing section 3.

In the inkjet printing device according to this embodiment, the first inlet roller 32 of the first printing section 3 is rotationally driven by a drive motor (not shown), but it may be a roller that rotates freely without a drive motor or the like. .
Further, in the first printing section 3, the drying section 31 includes an IR dryer 31a and a hot air dryer 31b having a spiral path, but the configuration of the drying section 31 is not limited to this.
Further, the first printing section 3 includes a feed roller 34, a nip roller 34a, a CUE mark sensor 36, an automatic register camera 38, a tension detection device 37, a cooling roller 35, etc., but these are not essential components.

Similarly, although the second inlet roller 42 of the second printing section 4 is rotationally driven by a drive motor (not shown), it may be a roller that rotates freely without a drive motor or the like.
Further, in the second printing section 4, the drying section 41 includes an IR dryer 41a and a hot air dryer 41b having a spiral path, but the configuration of the drying section 41 is not limited to this.
Further, the second printing section 4 includes a feed roller 44, a nip roller 44a, a CUE mark sensor 46, an automatic registration camera 48, a cooling roller 45, etc., but these are not essential components.

In the inkjet printing device according to this embodiment, the first printing section 3 prints color ink, and the second printing section 4 prints white ink, but the invention is not limited thereto.
Also, the ink may be reversed. That is, the first printing section 3 may print white ink, and the second printing section 4 may print color ink. In this case, when the first conveyance path is used, a front side printed matter is obtained, and when the second conveyance path is passed, a back side printed matter is obtained.

In the inkjet printing device according to the present embodiment, water-based color ink and water-based white ink are used, but ultraviolet curable color ink and white ink may also be used. In this case, a UV irradiator is installed instead of the drying section.

In the inkjet printing device according to the present embodiment, the post-processing unit 5 applies an overcoat liquid to the printing substrate X to form an overcoat layer, but is not limited to this, and for example, lamination processing, etc. You may also do this.
Further, the post-processing section 5 includes a downstream base point roller 54, a cooling roller 53, etc., but these are not essential components.
Note that when the post-processing section 5 is not provided, the downstream base point roller 54 is provided on the conveyance path between the second printing section 4 and the discharge section 6, and when the post-processing section 5 is not provided with the downstream base point roller 54. , the downstream base point roller 54 is provided on the conveyance path between the second printing section 4 and the post-processing section 5.

In the inkjet printing device according to the present embodiment, the discharge unit 6 adopts a method of winding the printed substrate X around a winding shaft 60. However, if the printing substrate X can be collected, , but not limited to. For example, a shake-off method or the like may be adopted.
Furthermore, although the discharge section 6 includes a dancer 62 and the like, this is not an essential configuration.

In the inkjet printing device according to this embodiment, the pre-processing section 2 and the first printing section 3 are connected via the communication section C1, and the first work space section S1 is provided above the communication section C1. , is not a required configuration.
Further, the first printing section 3 and the second printing section 4 are connected via a communication section C2, and a second work space section S2 is provided above the communication section C2, but this is not an essential configuration.
Further, the second printing section 4 and the post-processing section 5 are connected via a communication section C3, and a third work space section S3 is provided above the communication section C3, but this is not an essential configuration.

In the inkjet printing device according to the present embodiment, a downstream base point nip roller 54a is attached to the downstream base point roller 54 as a gripping means, a first inlet nip roller 32a is attached to the first entrance roller 32 as a gripping means, and a first inlet nip roller 32a is attached to the first entrance roller 32 as a gripping means. A first outlet nip roller 33a is attached to the roller 33 as a grasping means, a second inlet nip roller 42a is attached to the second inlet roller 42 as a grasping means, and a second outlet nip roller 43a is attached to the second outlet roller 43 as a grasping means. However, the gripping means are not limited to these.

In the inkjet printing device 100 according to the first embodiment, a first unused printing substrate X1, a second unused printing substrate X2, and a third unused printing substrate X3 are arranged. is not essential, and the arrangement position is not limited to the positions shown in FIGS. 2 and 3.
Similarly, in the inkjet printing device according to the second embodiment, a first unused printing substrate X1a, a second unused printing substrate X2a, and a third unused printing substrate X3a are arranged. , these are not essential, and the arrangement position is not limited to the position shown in FIG. 6.

In the inkjet printing device 100 according to the first embodiment, a first upstream end nip roller 71a is attached to the first upstream end roller 71 as a holding means, and a first upstream end nip roller 71a is attached to the first downstream end roller 72 as a holding means. A first downstream end nip roller 72a is attached, a second upstream end nip roller 73a is attached to the second upstream end roller 73 as a holding means, and a second downstream end nip roller 73a is attached to the second downstream end roller 74 as a holding means. A side end nip roller 74a is attached, a third upstream end nip roller 75a is attached to the third upstream end roller 75 as a holding means, and a third downstream end nip roller 75a is attached to the third downstream end roller 76 as a holding means. Although a partial nip roller 76a is attached, the holding means is not limited thereto.
Note that the same applies to the inkjet printing device according to the second embodiment.

The inkjet printing device of the present invention can be used as a device for printing designs such as letters and patterns by making ink into fine droplets and spraying them directly onto the printing substrate X.
In addition, when an inkjet printing device uses a transparent or translucent film as the printing substrate X, by switching the conveyance path of the printing substrate X, front printing and back printing can be performed with the same device. It can be carried out.

DESCRIPTION OF SYMBOLS 1... Supply part 10... Supply shaft 100... Inkjet printing device 101... Back printed matter 102... Front printed matter 11... Meandering prevention device 12, 62... Dancer 13, 34, 44, 61... Feed roller 13a, 23a, 34a, 35a, 44a, 45a, 53a, 61a... Nip roller 14, 37... Tension detection device 1a, 2a, 3a, 4a, 5a , 6a... Housing 2... Pretreatment section 20... Corona treatment device 21, 51... Coater processing device 22, 52... IR dryer 23, 35, 45, 53... Cooling Roller 24... Upstream base point roller 3... First printing section 30, 40... Print head 31, 41... Drying section 31a, 41a... IR dryer 31b, 41b... Hot air drying Machine 32...First entrance roller 32a...First entrance nip roller 33...First exit roller 33a...First exit nip roller 36, 46...CUE mark sensor 38, 48...Automatic registration Camera 4...Second printing section 42...Second entrance roller 42a...Second entrance nip roller 43...Second exit roller 43a...Second exit nip roller 5...Post-processing section 54. ...Downstream base point roller 54a...Downstream base point nip roller 6...Discharge section 60...Take-up shaft 7...Image reading section 71, 81...First upstream end roller 71a, 81a ...First upstream end nip roller 72, 82...First downstream end roller 72a, 82a...First downstream end nip roller 73, 83...Second upstream end roller 73a , 83a... Second upstream end nip roller 74, 84... Second downstream end roller 74a, 84a... Second downstream end nip roller 75, 85... Third upstream end Rollers 75a, 85a... Third upstream end nip roller 76, 86... Third downstream end roller 76a, 86a... Third downstream end nip roller A1, B1... Ink receiving layer A11 , B11... Design image A12, B12... Background image A2, B2... Overcoat layer C1, C2, C3... Connection portion P... Rear lower part R1, R1a... First conveyance path R2, R2a...Second transport path S1...First work space S2...Second work space S3...Third work space X...Printed substrate X1, X1a...・First unused printing substrate X11, X1a1, X21, X2a1, X31, X3a1... Upstream end X12, X1a2, X22, X2a2, X32, X3a2... Downstream end X2, X2a...・Second unused printing substrate X3, X3a...Third unused printing substrate

Claims (10)

An inkjet printing device that has a plurality of conveyance paths for a printing target substrate, and can reverse the printing order in a first printing section and a second printing section by switching the conveyance paths,
a supply unit for supplying the printing substrate;
the first printing section and the second printing section that print on the printing substrate and dry it;
a discharge section for collecting the printed substrate;
Equipped with
The supply section, the first printing section, the second printing section, and the discharge section are arranged in series in this order,
At least a first conveyance path that prints on one side of the printing substrate in the order of the first printing section and the second printing section, and a first printing section that prints on one side of the printing substrate in the order of the second printing section and the first printing section. An inkjet printing device having a second conveyance path for printing. An upstream base point roller is provided between the supply section and the first printing section,
A downstream base point roller is provided between the second printing section and the discharge section,
The first printing section includes a first entrance roller for guiding the printing substrate into the first printing section, and a first entrance roller for guiding the printing substrate from the first printing section to the outside. 1 exit roller;
The second printing section includes a second entrance roller for guiding the printing substrate into the second printing section, and a second entrance roller for guiding the printing substrate from the second printing section to the outside. It has two exit rollers,
In the first conveyance path, the printing substrate is conveyed from the upstream base point roller to the first entrance roller, conveyed from the first exit roller to the second entrance roller, and conveyed from the first exit roller to the second entrance roller. from the base point roller on the downstream side,
In the second conveyance path, the printing substrate is conveyed from the upstream base point roller to the second entrance roller, conveyed from the second exit roller to the first entrance roller, and is conveyed from the second exit roller to the first entrance roller. 2. The inkjet printing device according to claim 1, wherein the inkjet printing device is conveyed from the downstream base point roller to the downstream base point roller. Inkjet printing according to claim 2, wherein the first entrance roller, the first exit roller, the second entrance roller, and the second exit roller are provided with gripping means for gripping the printing target substrate. Device. further comprising a pre-treatment unit for forming an ink-receiving layer on the printing substrate,
The pre-processing section is arranged between the supply section and the first printing section,
The pre-processing section includes the upstream base point roller,
The inkjet printing device according to claim 2 or 3, wherein the upstream base point roller guides the printing target substrate from the pretreatment section to the outside. A work space is provided between the pre-processing section and the first printing section and between the first printing section and the second printing section, respectively, for performing a switching operation,
The inkjet printing device according to claim 4, wherein the first conveyance path and the second conveyance path are provided above the work space. further comprising a post-processing section for forming an overcoat layer on the printing substrate,
The post-processing section is arranged between the second printing section and the discharge section,
The post-processing section has the downstream base point roller,
The inkjet printing device according to any one of claims 2 to 5, wherein the downstream base point roller guides the printing substrate into the post-processing section. The ink used for printing in one of the first printing section and the second printing section is at least one selected from the group consisting of yellow ink, magenta ink, cyan ink, and black ink,
The inkjet printing device according to any one of claims 1 to 6, wherein the ink used for printing on the other hand is white ink. An unused printing substrate for the transport route that is not used among the first transport route and the second transport route, and that does not overlap with the first transport route and the second transport route. The inkjet printing device according to any one of claims 1 to 7, wherein the inkjet printing device is provided with: 9. The inkjet printing apparatus according to claim 8, wherein holding means for holding the unused printing substrate are attached to rollers located at both ends of the unused printing substrate. The inkjet printing device according to any one of claims 1 to 9, wherein the printing substrate is a transparent or translucent film for packaging.

Images