Blowing unit, drying device, liquid applying system, and printing system

Provided are a blowing unit, a drying device, a liquid applying system, and a printing system with which it is possible to realize uniformly blowing air via a plurality of jetting ports.In a blowing unit that has a hollow structure and blows air via a plurality of jetting ports disposed at a first surface, a gas inflow port through which a gas supplied from a gas supply source flows in is formed in a second surface which intersects the first surface and at which the jetting ports are not disposed and a ratio of a sum of opening areas of the plurality of jetting ports to an opening area of the gas inflow port is equal to or larger than 0.1 and equal to or smaller than 1.0.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims priority under 35 U.S.C § 119(a) to Japanese Patent Application No. 2021-103380 filed on Jun. 22, 2021, which is hereby expressly incorporated by reference, in its entirety, into the present application.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a blowing unit, a drying device, a liquid applying system, and a printing system.

2. Description of the Related Art

An ink jet printing apparatus that includes a drying device performing a drying process on a paper sheet, a film substrate, or the like on which a color image has been printed is known. Described in JP2002-292841A is an ink jet printer including a drying unit that dries ink landed on image receiving paper by means of hot air. The drying unit described in JP2002-292841A introduces air into a hollow casing having a rectangular parallelepiped shape and jets hot air via a plurality of jetting ports formed in the casing. A circular shape is applied to the plurality of jetting ports formed in a bottom surface of the casing and two-dimensional disposition is applied thereto.

SUMMARY OF THE INVENTION

However, although there is description in JP2002-292841A that any material having a sufficient heat resistance against jetted hot air can be used for the casing, there is no description about the structure of the casing for uniformly jetting hot air via the plurality of jetting ports. In addition, although there is description about drying uniformity in JP2002-292841A that a two-dimensional slit plate or the like described in JP1997-0133998A (JP-H9-0133998) can be applied, there is no description about the specific structure of the casing.

The present invention has been made in consideration of such circumstances and an object of the present invention is to provide a blowing unit, a drying device, a liquid applying system, and a printing system with which it is possible to realize uniformly blowing air via a plurality of jetting ports.

In order to achieve the above-described object, the following aspects of the invention are provided.

According to an aspect of the present disclosure, there is provided a blowing unit that has a hollow structure and blows air via a plurality of jetting ports disposed at a first surface. A gas inflow port through which a gas supplied from a gas supply source flows in is formed in a second surface which intersects the first surface and at which the jetting ports are not disposed and a ratio of a sum of opening areas of the plurality of jetting ports to an opening area of the gas inflow port is equal to or larger than 0.1 and equal to or smaller than 1.0.

In the case of the blowing unit according to the aspect of the present disclosure, the ratio of the sum of the opening areas of the plurality of jetting ports to the opening area of the gas inflow port through which the gas from the gas supply source is supplied is equal to or larger than 0.1 and equal to or smaller than 1.0. Accordingly, it is possible to realize uniformly blowing air via the plurality of jetting ports.

For the blowing unit, a columnar structure of which a bottom surface has a polygonal planar shape like a rectangular parallelepiped can be adopted.

The ratio of the sum of the opening areas of the plurality of jetting ports to the opening area of the gas inflow port is more preferably equal to or larger than 0.4 and equal to or smaller than 0.7.

For the jetting port, a through hole formed in the first surface that is flat can be applied. A circular shape can be applied as the opening shape of the jetting port.

In the blowing unit according to another aspect, the second surface may be brought into contact with a gas supply port disposition surface of the gas supply source at which a gas supply port is disposed so that the gas inflow port is bonded to the gas supply port.

According to such an aspect, the gas supply source can be disposed at a position near the blowing unit.

In the blowing unit according to another aspect, the blowing unit may be formed by using one kind of metal plate having a thickness equal to or larger than 1.5 mm and smaller than 3.5 mm.

According to such an aspect, it is possible to form a blowing unit preferable in terms of workability of a metal plate at the time of formation of the blowing unit, pressure loss in the blowing unit, and the thermal responsiveness of the blowing unit.

In the blowing unit according to another aspect, a plurality of the first surfaces may be provided.

According to such an aspect, air can be blown in a plurality of directions from one blowing unit. Accordingly, it is possible to compactly configure a drying unit in which the blowing unit is accommodated in comparison with a case where a plurality of blowing units that blow air in a plurality of directions respectively are provided.

In the blowing unit according to another aspect, two-dimensional disposition may be applied to disposition of the plurality of jetting ports at the first surface.

According to such an aspect, air can be blown two-dimensionally from the first surface.

In the blowing unit according to another aspect, a length of the blowing unit in a longitudinal direction may correspond to a length of any one side of a substrate to which air is blown.

According to such an aspect, it is possible to blow air to the entire surface of the substrate by causing the blowing unit and the substrate to which air is blown to scan each other once.

According to an aspect of the present disclosure, there is provided a drying device including a blowing unit that has a hollow structure and blows air via a plurality of jetting ports disposed at a first surface and a gas supply unit that supplies a gas to the blowing unit. The blowing unit is provided with a gas inflow port through which a gas supplied from a gas supply source flows in and that is formed in a second surface which intersects the first surface and at which the jetting ports are not disposed and a ratio of a sum of opening areas of the plurality of jetting ports to an opening area of the gas inflow port is equal to or larger than 0.1 and equal to or smaller than 1.0.

In the case of the drying device according to the aspect of the present disclosure, it is possible to achieve the same actions and effects as the blowing unit according to the above-described aspect of the present disclosure. The constituent requirements of the blowing unit according to another aspect can be applied to the drying device of a liquid applying system according to another aspect.

In the drying device according to another aspect, the gas supply unit may include a heat source and a fan motor that generates an air stream toward the heat source.

According to such an aspect, a drying process to which a heated gas is applied can be performed.

According to an aspect of the present disclosure, there is provided a liquid applying system including a liquid applying device that applies liquid to a substrate and a drying device that blows air to a substrate transport surface in a substrate transport path to dry the substrate to which the liquid has been applied. The drying device includes a blowing unit that has a hollow structure and blows air via a plurality of jetting ports disposed at a first surface and a gas supply unit that supplies a gas to the blowing unit, the blowing unit is provided with a gas inflow port through which a gas supplied from a gas supply source flows in and that is formed in a second surface which intersects the first surface and at which the jetting ports are not disposed, and a ratio of a sum of opening areas of the plurality of jetting ports to an opening area of the gas inflow port is equal to or larger than 0.1 and equal to or smaller than 1.0.

In the case of the liquid applying system according to the aspect of the present disclosure, it is possible to achieve the same actions and effects as the blowing unit according to the above-described aspect of the present disclosure. The constituent requirements of the blowing unit according to another aspect can be applied to the constituent requirements of the liquid applying system according to another aspect.

According to an aspect of the present disclosure, there is provided a printing system including a printing apparatus that prints an image on a substrate and a drying device that blows air to a substrate transport surface in a substrate transport path to dry the substrate on which the image has been printed. The drying device includes a blowing unit that has a hollow structure and blows air via a plurality of jetting ports disposed at a first surface and a gas supply unit that supplies a gas to the blowing unit, the blowing unit is provided with a gas inflow port through which a gas supplied from a gas supply source flows in and that is formed in a second surface which intersects the first surface and at which the jetting ports are not disposed, and a ratio of a sum of opening areas of the plurality of jetting ports to an opening area of the gas inflow port is equal to or larger than 0.1 and equal to or smaller than 1.0.

In the case of the printing system according to the aspect of the present disclosure, it is possible to achieve the same actions and effects as the blowing unit according to the above-described aspect of the present disclosure. The constituent requirements of the blowing unit according to another aspect can be applied to the constituent requirements of the printing system according to another aspect.

According to the aspects of the present disclosure, the ratio of the sum of the opening areas of the plurality of jetting ports to the opening area of the gas inflow port through which the gas from the gas supply source is supplied is equal to or larger than 0.1 and equal to or smaller than 1.0. Accordingly, it is possible to realize uniformly blowing air via the plurality of jetting ports.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings. In the present specification, the same components will be given the same reference numerals and repetitive description thereof will be appropriately omitted.

Overall Configuration of Ink Jet Printing System

FIG.1is an entire configuration view of an ink jet printing system according to an embodiment. Arrow lines shown in the drawing represent a substrate transport direction, which is a transport direction of a film substrate1in each device provided in an ink jet printing system10. The substrate transport direction is a direction in which the film substrate1proceeds.

The ink jet printing system10is a printing system to which a single-pass method is applied and prints a color image on a film substrate1by using aqueous color ink. The film substrate1is a transparent medium used for soft packaging and is an impermeable medium.

Examples of the film substrate1include oriented nylon (ONY), oriented polypropylene (OPP), and polyethylene terephthalate (PET). The ink jet printing system10creates a back-printed printed article visible from a substrate support surface1B that is on a side opposite to a printing surface1A with respect to the film substrate1. The ink jet printing system10can also create a front-printed printed article visible from the printing surface1A.

Being impermeable means being impermeable to aqueous primer and aqueous ink which will be described later. Soft packaging means packaging performed by using a material that is deformed depending on the shape of an article to be packaged. Being transparent means having a visible light transmittance equal to or higher than 30% and equal to or lower than 100%, preferably a visible light transmittance equal to or higher than 70% and equal to or lower than 100%.

The ink jet printing system10includes a paper feeding device12, a pre-coating device14, a jetting device16, a drying device18, an examination device20, a recovery device22, and a transport device24. Hereinafter, each part will be described in detail.

Paper Feeding Device

A roll-to-roll transport method is applied to the ink jet printing system10. The paper feeding device12includes a feed roll around which the film substrate1before printing of an image is wound. The feed roll includes a reel that is rotatably supported.

The paper feeding device12may include a corona treatment device that performs a reforming process on the printing surface1A of the film substrate1. The printing surface1A of the film substrate1that has been subjected to the reforming process has a surface free energy suitable for an aqueous mixture of aqueous primer and aqueous ink and can secure a wettability suitable for the aqueous mixture. The film substrate1is transported to the pre-coating device14.

The pre-coating device14is disposed at a position that is downstream of the paper feeding device12and upstream of the jetting device16in the substrate transport direction. The pre-coating device14applies pre-coating liquid to the printing surface1A of the film substrate1.

The pre-coating device14may include a pre-coating drying device. The pre-coating drying device dries the pre-coating liquid applied to the film substrate1. As the pre-coating liquid, liquid such as aqueous primer liquid which contains a component that insolubilizes or thickens aqueous ink may be applied. The film substrate1to which the pre-coating liquid has been applied and on which the pre-coating liquid has been dried is transported to the jetting device16. The pre-coating drying device may have the same configuration as the drying device which will be described later.

Jetting Device

The jetting device16includes an ink jet head30K, an ink jet head30C, an ink jet head30M, an ink jet head30Y, and an ink jet head30W.

The ink jet head30K, the ink jet head30C, the ink jet head30M, the ink jet head30Y, and the ink jet head30W jet black ink, cyan ink, magenta ink, yellow ink, and white ink, respectively. Hereinafter, in a case where it is not necessary to distinguish the ink jet head30K and the like, the ink jet head30K and the like will be described as the ink jet heads30.

Aqueous ink jetted from the ink jet heads30is ink obtained by dissolving or dispersing a coloring material such as a pigment in a water-soluble solvent. As the pigment in the aqueous ink, an organic pigment is used. The viscosity of the aqueous ink is equal to or higher than 0.5 centipoises and equal to or lower than 5.0 centipoises.

The ink jet heads30jet color ink onto the printing surface1A of the film substrate1transported by means of the transport device24to print a color image on the film substrate1. White ink forms a white background image on the film substrate1. A plurality of ink jet heads30W for jetting aqueous white ink may be provided.

For the ink jet heads30, disposition and orientation are applied such that nozzle surfaces from which ink is jetted are positioned and directed to face a substrate transport surface of a substrate transport path which is a transport path of the film substrate1. The ink jet heads30are disposed at equal intervals along the substrate transport direction.

The ink jet heads30include a plurality of nozzles. Each nozzle may include a nozzle opening and an ink flow channel. An energy generating element is provided for each of the nozzles of the ink jet heads30. Nozzle openings are two-dimensionally disposed in the nozzle surfaces of the ink jet heads30. Water-repellent films are formed on the nozzle surfaces of the ink jet heads30.

Piezoelectric elements may be applied as the energy generating elements. The ink jet heads30including the piezoelectric elements jet ink droplets via the nozzle openings by using bending deformation of the piezoelectric elements. Heaters may be applied as the energy generating elements. The ink jet heads30including the heaters jet ink droplets via the nozzle openings by using the film boiling phenomenon of ink.

As the ink jet heads30, line-type heads, in each of which a plurality of nozzles are disposed over the entire length of the film substrate1in a substrate width direction, are applied. Note that, serial-type heads may be applied as the ink jet heads30.

For the line-type ink jet heads30, a structure in which a plurality of head modules are connected in the substrate width direction may be applied. The substrate width direction is a direction orthogonal to the substrate transport direction and is a direction parallel to a printing surface of the film substrate1.

FIG.1shows a configuration in which aqueous ink of four colors are applied. However, the colors of ink are not limited to the four colors (black, cyan, magenta, and yellow). For example, a configuration in which ink of a light color such as light magenta and light cyan is applied and a configuration in which ink of a special color such as green, orange, violet, clear, and metallic is applied can also be applied. In addition, the order in which the ink jet heads for the respective colors are disposed is not limited to an example shown inFIG.1.

The jetting device16includes a scanner32. The scanner32includes an image pick-up device that images a test pattern image printed on the printing surface of the film substrate1and converts a captured image into an electric signal.

Examples of the image pick-up device include a CCD image sensor and a color CMOS image sensor. “CCD” is the abbreviation for “Charge Coupled Device”. “CMOS” is the abbreviation for “Complementary Metal Oxide Semiconductor”.

Image pick-up data output from the scanner32is transmitted to a test pattern determination unit. The test pattern determination unit specifies a defective nozzle or the like based on the image pick-up data of a test pattern. The test pattern determination unit is shown inFIG.2with a reference numeral “172” given thereto.

The film substrate1from which the test pattern image has been captured by means of the scanner32is transported to the drying device18.

Drying Device

The drying device18is disposed at a position that is downstream of the jetting device16in the substrate transport direction and upstream of the examination device20in the substrate transport direction. The drying device18includes a drying module that dries aqueous ink adhering to the printing surface1A of the film substrate1. The film substrate1after the drying of the aqueous ink is transported to the examination device20. The details of the drying device will be described later.

Examination Device

The examination device20is disposed at a position that is downstream of the drying device18in the substrate transport direction and upstream of the recovery device22in the substrate transport direction. The examination device20examines whether or not there is a defect in an image printed on the film substrate1.

The examination device20includes an imaging device that images an image printed on the film substrate1and an illumination device that irradiates the film substrate1with illumination light. Image pick-up data of the printed image is blown to a printed image determination unit. The printed image determination unit determines whether or not there is a defect in the printed image based on the image pick-up of the printed image. Note that the printed image determination unit is shown inFIG.2with a reference numeral “173” given thereto.

The film substrate1after examination of a captured image that is performed by means of the examination device20is transported to the recovery device22.

Recovery Device

The recovery device22recovers the film substrate1on which an image has been printed. Specifically, the film substrate1on which the image has been printed is wound onto a winding roll.

Transport Device

A roll-to-roll method is applied to the transport device24. The transport device24transports the film substrate1from the paper feeding device12to the recovery device22along the substrate transport path in the substrate transport direction in this order: the paper feeding device12, the pre-coating device14, the jetting device16, the drying device18, the examination device20, and the recovery device22. The paper feeding device12and the recovery device22may be included in the transport device24.

The transport device24includes a plurality of pass rollers34. One or more pass rollers34are disposed in each of the paper feeding device12, the pre-coating device14, the jetting device16, the drying device18, the examination device20, and the recovery device22.

The transport device24includes tension pickups36, and one or more tension pickups36are disposed in each of the paper feeding device12, the pre-coating device14, the jetting device16, the drying device18, the examination device20, and the recovery device22. The tension pickups36detect tension applied to the film substrate1. A detection signal of the tension pickups36is blown to a transport controller. Note that the transport controller is shown inFIG.2with a reference numeral “162” given thereto. InFIG.1, the tension pickup36provided in the jetting device16is shown and the tension pickups36provided in the paper feeding device12and the like are not shown.

Electric Configuration of Ink Jet Printing System

FIG.2is a functional block diagram showing an electric configuration of the ink jet printing system shown inFIG.1. The ink jet printing system10includes a system controller160, the transport controller162, a pre-coating controller164, a jetting controller166, a drying controller168, an examination controller170, the test pattern determination unit172, and the printed image determination unit173.

The system controller160comprehensively controls the overall operation of the ink jet printing system10. The system controller160transmits command signals to various controllers. The system controller160functions as a memory controller that controls the storing of data in a memory174and the reading of data from the memory174.

The system controller160acquires a sensor signal transmitted from a sensor176and transmits command signals based on the sensor signal to various controllers. The sensor176shown inFIG.2includes the tension pickup36shown inFIG.1. In addition, the sensor176includes a position detection sensor, a temperature sensor, and the like provided in each part of the ink jet printing system10.

The transport controller162sets transport conditions based on the command signal transmitted from the system controller160and controls the operation of the transport device24based on the set transport conditions. For example, the transport controller162applies transport conditions applied to the transport device24to control the operation of a motor connected to a drive roller or the like provided in the transport device24.

In addition, the transport controller162individually controls transport tension applied to the film substrate1in each of sections such as the pre-coating device14and the jetting device16provided in the ink jet printing system10. That is, the transport controller162controls transport tension of the film substrate1in each section over an area from the paper feeding device12to the recovery device22.

The pre-coating controller164sets pre-coating process conditions based on the command signal transmitted from the system controller160and controls the operation of the pre-coating device14based on the set pre-coating process conditions.

The jetting controller166sets printing conditions based on the command signal transmitted from the system controller160and controls the operation of the jetting device16based on the set printing conditions.

The jetting controller166includes an image processing unit that performs a color decomposition process, a color conversion process, a correction process for each process, and a halftone process with respect to printing data to generate halftone data based on the printing data.

The jetting controller166includes a drive voltage generation unit that generates a drive voltage to be supplied to the ink jet heads30. The jetting controller166includes a drive voltage output unit that supplies the drive voltage to the ink jet heads30.

The drying controller168sets process conditions for a drying process applied to the drying device18based on the command signal transmitted from the system controller160and controls the operation of the drying device18based on the set drying process conditions.

The examination controller170sets examination conditions applied to the examination device20based on the command signal transmitted from the system controller160and controls the operation of the examination device20based on the set examination conditions.

The test pattern determination unit172acquires image pick-up data of a test pattern and analyzes the image pick-up data of the test pattern. The test pattern determination unit172determines whether or not there is a jetting abnormality of the ink jet heads30based on the result of the analysis.

The printed image determination unit173acquires image pick-up data of a printed image and analyzes the image pick-up data of the printed image. The printed image determination unit173determines whether or not there is an image defect in the printed image based on the result of the analysis.

FIG.3is a block diagram showing a configuration example of the hardware of the electric configuration shown inFIG.2. A control device200included in the ink jet printing system10includes a processor202, a non-temporary tangible computer-readable medium204, a communication interface206, and an input and output interface208.

A computer is applied as the control device200. The form of the computer may be a server, a personal computer, a workstation, a tablet terminal, or the like.

The processor202includes a central processing unit (CPU). The processor202may include a graphics processing unit (GPU). The processor202is connected to the computer-readable medium204, the communication interface206, and the input and output interface208via a bus210. An input device214and a display device216are connected to the bus210via the input and output interface208.

The computer-readable medium204includes a memory as a main memory and a storage as an auxiliary storage. A semiconductor memory, a hard disk apparatus, a solid state drive device, or the like can be applied as the computer-readable medium204. Any combination of a plurality of devices may be applied as the computer-readable medium204.

The hard disk device may be referred to as an HDD, which is the abbreviation for “Hard Disk Drive” in English. The solid state drive device may be referred to as SSD, which is the abbreviation for “Solid State Drive” in English.

The control device200is connected to a network via the communication interface206and is connected to an external device such that communication can be performed. As the network, a local area network (LAN) or the like may be applied. The network is not shown.

The computer-readable medium204stores a transport control program220, a pre-coating control program222, a jetting control program224, a drying control program226, an examination control program228, and a test pattern determination program230.

The transport control program220corresponds to transport control applied to the transport device24shown inFIG.2. The pre-coating control program222corresponds to pre-coating control applied to the pre-coating device14.

The jetting control program224corresponds to printing control applied to the jetting device16. The drying control program226corresponds to drying control applied to the drying device18.

The examination control program228corresponds to printed image examination applied to the examination device20. The test pattern determination program230is applied to jetting abnormality determination based on the image pick-up data of the test pattern.

The various programs stored in the computer-readable medium204include one or more instructions. The computer-readable medium204stores various data, various parameters, and the like. The memory174shown inFIG.2is included in the computer-readable medium204shown inFIG.3.

In the ink jet printing system10, the processor202executes the various programs stored in the computer-readable medium204to realize various functions in the ink jet printing system10. Note that the term “program” has the same meaning as “software”.

The control device200performs data communication with the external device via the communication interface206. Various standards such as universal serial bus (USB) can be applied to the communication interface206. Any of wired communication or wireless communication may be applied as the way in which the communication interface206performs communication.

The input device214and the display device216are connected to the control device200via the input and output interface208. An input device such as a keyboard and a mouse is applied as the input device214. Various kinds of information applied to the control device200are displayed by the display device216.

A liquid crystal display, an organic EL display, a projector, or the like may be applied as the display device216. Any combination of a plurality of devices may be applied as the display device216. “EL” of the organic EL display is the abbreviation for “Electro-Luminescence”.

Here, examples of the hardware structure of the processor202include a CPU, a GPU, a programmable logic device (PLD), and an application specific integrated circuit (ASIC). The CPU is a general-purpose processor that executes a program to act as various functional units. The GPU is a processor specialized in image processing.

The PLD is a processor that can change the configuration of an electric circuit after manufacture of a device. Examples of the PLD include a field programmable gate array (FPGA). The ASIC is a processor with a dedicated electric circuit specifically designed to perform a specific process.

One processing unit may be composed of one of these various processors or may be composed of two or more processors of the same type or different types. Examples of a combination of various processors include a combination of one or more FPGAs and one or more CPUs and a combination of one or more FPGAs and one or more GPUs. Another example of a combination of various processors is a combination of one or more CPUs and one or more GPUs.

A plurality of functional units may be configured by using one processor. Examples of a configuration in which a plurality of functional units are configured by using one processor include a configuration in which a combination of one or more CPUs and software like a System-On-a-Chip (SoC) that is represented by a computer such as a client or a server is applied to configure one processor and the processor acts as a plurality of functional units.

Another example of a configuration in which a plurality of functional units are configured by using one processor is a configuration in which a processor that uses one IC chip to realize the functions of the entire system including a plurality of functional units is used. Note that “IC” is the abbreviation for “Integrated Circuit”.

As described above, various functional units are configured by using one or more of the above-mentioned various processors as the hardware structure. Furthermore, the hardware structure of the various processors described above is, more specifically, an electric circuit (circuitry) in which circuit elements such as semiconductor elements are combined with each other.

The computer-readable medium204may include a semiconductor element such as a read only memory (ROM) and a random access memory (RAM). The computer-readable medium204may include a magnetic storage medium such as a hard disk. The computer-readable medium204may include a plurality of types of storage media.

The ink jet printing system10described in the embodiment is an example of a liquid applying system. The pre-coating device14and the jetting device16according to the embodiment are examples of a liquid applying device.

Detailed Description of Drying Device

First Embodiment

FIG.4is a front view showing a configuration example of a drying module according to a first embodiment. The reference numeral “X” shown inFIG.4represents the substrate width direction. In addition, the reference numeral “Z” represents a vertically upward direction. The same applies to the reference numerals “X” and “Z” shown inFIGS.5to9.

A drying module1801includes a nozzle unit300and a heater unit320. The drying module1801generates a heated gas of which the temperature falls in a predetermined range in the heater unit320which is a component different from the nozzle unit300and supplies the heated gas to the nozzle unit300. Air may be applied as the heated gas.

The heater unit320is disposed at a non-facing position of the substrate transport path at which the heater unit320does not face the substrate transport path. In addition, the heater unit320is disposed at a position near the nozzle unit300. Accordingly, a reduction in pressure loss of the heated gas and a reduction in heat loss of the heated gas are realized. The heater unit320shown inFIG.4is bonded to a side surface306which is an end301of the nozzle unit300that is on one side in substrate width direction.

AlthoughFIG.4shows a configuration in which the side surface306of the nozzle unit300and a gas supply port disposition surface327, which is an end of the heater unit320that is on one side in the substrate width direction, are bonded to each other, the nozzle unit300and the heater unit320may be bonded to each other via a duct or the like having such a length that the flow of the heated gas is not influenced.

The nozzle unit300has a structure that realizes uniform supply of the heated gas to a plurality of nozzles304, so that uniform supply of heat to the plurality of nozzles304is automatically achieved. Note that uniformity mentioned here may include a variation within a prescribed miscalculation range.

The nozzle unit300has a rectangular parallelepiped shape and has a length exceeding the total length of the film substrate1in the substrate width direction. In the nozzle unit300, the plurality of nozzles304are disposed at a nozzle disposition surface302that faces the substrate transport surface. The plurality of nozzles304are disposed over a length exceeding the total length of one side of the film substrate1in the substrate width direction. Examples of the disposition of the plurality of nozzles304at the nozzle disposition surface302include two-dimensional disposition. An example of the two-dimensional disposition of the plurality of nozzles304is shown inFIG.7.

Note that the substrate width direction described in the embodiment is an example of the longitudinal direction of the blowing unit. The total length of one side of the film substrate1in the substrate width direction described in the embodiment is an example of the length of any one side of a substrate. The film substrate1described in the embodiment is an example of a substrate to which air is sent.

Each nozzle304has a protruding shape protruding from the nozzle disposition surface302and a nozzle opening is formed at a distal end thereof. The nozzles304blow the heated gas, which is a gas subjected to heating, toward the printing surface1A of the film substrate1via the nozzle openings. Downward arrow lines near the nozzles304represent a direction in which the heated gas is blown. Note that the blowing of the heated gas is the same concept as the jetting, the blasting, the releasing, and the like of the heated gas.

AlthoughFIG.4shows the nozzles304each having the protruding shape protruding from the nozzle disposition surface302, openings formed in the nozzle disposition surface302may be applied as the nozzles304. Any shape such as a circular shape and a quadrangular shape is applied to the planar shape of each nozzle opening.

Regarding the nozzle unit300, a through hole serving as a heated gas inflow port308through which the heated gas is supplied is formed in the side surface306that is orthogonal to the nozzle disposition surface302and that is parallel to the substrate transport direction. The heated gas generated in the heater unit320flows into the nozzle unit300via the heated gas inflow port308. Any shape such as a circular shape and a quadrangular shape is applied to the planar shape of the heated gas inflow port308.

Note that the nozzle disposition surface302described in the embodiment is an example of a first surface. The side surface306described in the embodiment is an example of a second surface that intersects a first surface and is an example of the second surface at which no jetting port is disposed. Each of the nozzles304described in the embodiment is an example of a jetting port.

The heater unit320includes a heater322and an axial fan324. The heater322and the axial fan324are disposed in the order of the heater322and the axial fan324in a direction away from the heated gas inflow port308.

The heater322heats air, which is a gas in the vicinity of the heater322, based on a prescribed set temperature. An infrared heater or the like may be applied as the heater322. The axial fan324blows air toward the heater322based on prescribed blowing conditions to generate a heated gas. Rightward arrow lines shown inFIG.4represent a direction in which the axial fan324blows air.

The heater unit320includes a heated gas supply port326at a position corresponding to the heated gas inflow port308of the nozzle unit300. The heated gas supply port326is formed in the gas supply port disposition surface327of a heater case323in which the heater322is provided. The opening shape and the opening area of the heated gas supply port326correspond to the heated gas inflow port308. For example, the heated gas supply port326may have the same shape and size as the heated gas inflow port308.

The drying module1801has a structure in which the side surface306of the nozzle unit300and the gas supply port disposition surface327of the heater unit320are in contact with each other and the heated gas inflow port308of the nozzle unit300and the heated gas supply port326of the heater unit320are bonded to each other.

The drying module1801including the nozzle unit300and the heater unit320is disposed inside a drying furnace330. The drying furnace330includes a transport path for the film substrate1on which a drying process is performed by means of the drying module1801.

According to such an embodiment, it is possible to realize a reduction in heat loss in the entire drying module1801. For example, in consideration of an influence on the lifespan or the like of the axial fan324, the drying module1801may be disposed inside the drying furnace330in a case where a relatively low heating temperature is applied.

Note that, the drying furnace330described in the embodiment is an example of a drying unit. The nozzle unit300described in the embodiment is an example of a blowing unit. The heater unit320described in the embodiment is an example of a heated gas supply unit and is an example of a gas supply source and a gas supply unit. In addition, the heater322described in the embodiment is an example of a heat source. The axial fan324described in the embodiment is an example of a fan motor.

FIG.5is a front view showing a modification example of the drying module shown inFIG.4. In the case of a drying module1801A according to the modification example, the nozzle unit300is disposed inside a drying furnace330A and the heater unit320is disposed outside the drying furnace330A.

That is, an opening332that has a size corresponding to the heated gas inflow port308and that is disposed corresponding to the heated gas inflow port308is formed in the drying furnace330A. An end surface331of the drying furnace330A that is on one side in the substrate width direction is bonded to the heater unit320with the opening332and the heated gas supply port326being positionally aligned with each other.

With the drying module1801A according to the modification example, maintenance such as replacement of the heater unit320can be efficiently performed. The drying furnace330A described in the embodiment is an example of a drying unit.

Second Embodiment

FIG.6is a plan view showing a configuration example of a drying module according to a second embodiment. A drying module1802according to the second embodiment includes a circulation structure that recycles the heated gas generated in the heater unit320.

The heater unit320shown inFIG.6is disposed outside the drying furnace330A. The heater322and the axial fan324constituting the heater unit320are accommodated inside a heated gas generation box360. Accordingly, the axial fan324can blow the heated gas in the heated gas generation box360to the nozzle unit300without escape of thermal energy generated by the heater322from the heated gas generation box360.

The heated gas generation box360includes a first intake port362through which outside air is taken in. The first intake port362may be disposed at any of surfaces constituting the heated gas generation box360.FIG.6shows a configuration in which the first intake port362is disposed at a surface that faces an intake surface of the axial fan324.

Third Embodiment

FIG.7is a bottom view showing a configuration example of a drying module according to a third embodiment.FIG.8is a perspective view showing an internal structure example of the drying module shown inFIG.7.FIGS.7and8are views of a drying module1803viewed as seen in a vertical direction from a lower side to an upper side.

Note that inFIGS.7and8, a drying furnace into which the nozzle unit300is built is not shown. In addition, reference numerals “X”, “Y”, and “Z” shown inFIGS.7and8represent the substrate width direction, the substrate transport direction in the drying module1803, and a vertically upward direction, respectively.

In the case of the drying module1803, a heated gas recovery unit370is disposed downstream of the nozzle unit300in the substrate transport direction. A heated gas discharge port372through which the heated gas is discharged is formed in an end surface371of the heated gas recovery unit370that is on one side in the substrate width direction. Note that the heated gas discharge port372is not shown inFIG.8.

Regarding the heated gas recovery unit370, a heated gas recovery port376is formed in a substrate facing surface374that faces the substrate transport surface. The heated gas recovery port376has a rectangular planar shape and the length thereof in the substrate width direction corresponds to a length by which the nozzles304are disposed.

A second intake port364is formed in an edge surface361of a heated gas generation box360A that is on the other side in the substrate width direction. The second intake port364is disposed at a position corresponding to the heated gas discharge port372and the opening shape and the size thereof corresponds to the heated gas discharge port372. For example, the second intake port364may have the same shape and size as the heated gas discharge port372.

In a case where the edge surface371of the heated gas recovery unit370that is on the one side and the edge surface361of the heated gas generation box360that is on the other side are brought into contact with each other and are bonded to each other, the second intake port364and the heated gas discharge port372are positionally aligned with each other.

In the case of the drying module1803having such a structure, the heated gas blown from the nozzle unit300is recovered to the heated gas recovery unit370via the heated gas recovery port376. The heated gas recovered to the heated gas recovery unit370is recovered to the heated gas generation box360A via the heated gas discharge port372and the second intake port364.

Accordingly, thermal energy circulation in which a high-temperature heated gas present in a drying furnace into which the nozzle unit300and the heated gas recovery unit370are built is taken into the heated gas generation box360A is realized and thus it is possible to achieve a power saving effect with the drying module1803.

The axial fan324functions as an air stream generating source at the time of circulation of the heated gas from the heated gas generation box360A to the heated gas generation box360A via the nozzle unit300and the heated gas recovery unit370.

FIG.7shows a rectangular parallelepiped shape and a hollow structure as examples of the shape and the structure of the heated gas recovery unit370. The heated gas recovery unit370may be disposed upstream of the nozzle unit300in the substrate transport direction.

As shown inFIG.7, the heated gas recovery port376is divided into three parts in the substrate width direction which is a longitudinal direction of the heated gas recovery unit370. That is, the heated gas recovery port376is divided into a first intake region376A, a second intake region376B, and a third intake region376C.

The heated gas recovery unit370includes a first intake flow channel378A communicating with the first intake region376A, a second intake flow channel378B communicating with the second intake region376B, and a third intake flow channel378C communicating with the third intake region376C.

That is, the heated gas recovery unit370includes a first partition wall379A that separates the first intake flow channel378A and the second intake flow channel378B from each other and a second partition wall379B that separates the second intake flow channel378B and the third intake region376C from each other.

The heated gas discharge port372is divided into a first discharge region372A connected to the first intake flow channel378A, a second discharge region372B connected to the second intake flow channel378B, and a third discharge region372C connected to the third intake flow channel378C.

The heated gas sucked from the first intake region376A is recovered to the heated gas generation box360A via the first intake flow channel378A and the first discharge region372A. Further, the heated gas sucked from the second intake region376B is recovered to the heated gas generation box360A via the second intake flow channel378B and the second discharge region372B.

Furthermore, the heated gas sucked from the third intake region376C is recovered to the heated gas generation box360A via the third intake flow channel378C and the third discharge region372C.

Note that, inFIG.7, arrow lines given to the first intake flow channel378A, the second intake flow channel378B, and the third intake flow channel378C schematically represent the heated gas recovered to the heated gas generation box360A via the heated gas recovery port376. In addition, inFIG.8, a plurality of curved lines are used to schematically represent the flow of the heated gas and arrow lines are used to represent a direction in which the heated gas flows as a whole.

In a case where a gas is taken into the heated gas recovery unit370via the heated gas recovery port376, the amount of suction per unit period tends to be relatively large at a first intake region376A side, which is a side close to the axial fan324, in comparison with a second intake region376B side, which is a side far from the axial fan324. Therefore, the heated gas discharge port372is divided into a plurality of regions and the first intake flow channel378A or the like which is a heated gas flow channel is provided for each region.

Accordingly, a variation in amount of intake per unit period in the substrate width direction is suppressed in the case of an intake performed via the heated gas recovery port376and thus an intake uniform in the substrate width direction is realized. The number of regions into which the heated gas recovery port376is divided and the number of regions into which the heated gas discharge port372is divided are not limited to numbers as in an example shown inFIG.7and any number may be applied as the numbers.

Note that the first intake region376A, the second intake region376B, and the third intake region376C described in the embodiment are an example of a plurality of intake regions of a heated gas recovery port partitioned in a longitudinal direction thereof.

In addition, the first discharge region372A, the second discharge region372B, and the third discharge region372C described in the embodiment are an example of a plurality of discharge regions of a heated gas discharge port partitioned corresponding to a plurality of intake regions.

Furthermore, each of the first intake flow channel378A, the second intake flow channel378B, and the third intake flow channel378C described in the embodiment is an example of an intake flow channel constituting a plurality of intake flow channels.

Fourth Embodiment

FIG.9is a bottom view showing a configuration example of a drying module according to a fourth embodiment. In the case of a drying module1804according to the fourth embodiment, the volume per unit period of the heated gas circulated from the heated gas recovery unit370to a heated gas generation box360B is controlled.

For the heated gas recovery unit370, complete circulation is applied in which all the heated gas blown from the nozzles304to the film substrate1is recovered via the heated gas recovery port376. In a case where a plurality of drying modules1804are provided and the plurality of drying modules1804are disposed along the substrate transport direction, at the drying module1804that is disposed at a position on an upstream side in the substrate transport direction, the amount of water evaporation may be relatively large and the humidity may rise to a relatively high humidity in comparison with the drying module1804that is disposed at a position on a downstream side in the substrate transport direction. The rise in humidity may decrease the efficiency of a drying process.

In the case of the drying module1804, the heated gas generation box360B is provided with a third intake port380. Fresh air from the outside of the drying module1804is taken into the heated gas generation box360B via the third intake port380, so that the humidity in the heated gas generation box360B is adjusted.

The third intake port380includes an opening area adjustment mechanism382that adjusts the opening area thereof. The opening area adjustment mechanism382may include a shutter and a shutter drive mechanism that drives the shutter.

A configuration in which a plurality of openings is provided may be applied as the third intake port380. In the case of a configuration in which a plurality of openings are provided as the third intake port380, a blocking mechanism that selectively blocks one or more of the plurality of openings may be applied as the opening area adjustment mechanism382.

Regarding the third intake port380, a pressure loss adjustment mechanism may be provided for the third intake port380instead of the opening area adjustment mechanism382or together with the opening area adjustment mechanism382. Note that the pressure loss adjustment mechanism is not shown. The drying controller168shown inFIG.2performs drive control or the like in the opening area adjustment mechanism382, the pressure loss adjustment mechanism, or the like.

The drying module1804may include at least one of a temperature sensor or a humidity sensor, detect at least one of the temperature or the humidity in the heated gas generation box360B, and control the operation of the opening area adjustment mechanism382or the like based on the result of the detection.

It is preferable that the temperature sensor or the like is disposed at a position near the second intake port364. Examples of the position near the second intake port364include a surface366at an inner side of the edge surface361in which the second intake port364is formed. The sensor176shown inFIG.2includes the temperature sensor or the like provided in the heated gas generation box360B.

Note that the opening area adjustment mechanism382described in the embodiment is an example of an adjustment mechanism that adjusts the volume per unit period of a gas passing through a third intake port.

Fifth Embodiment

FIG.10is a side view of a drying device that shows a configuration example of a drying device according to a fifth embodiment. Note that the drawing schematically shows an example of an internal structure of the drying furnace330A provided in the drying device18. In addition, in the drawing, the nozzle unit300disposed in the drying furnace330A is shown and the heater unit320disposed outside the drying furnace330A is not shown. An arrow line shown in the drawing represents the substrate transport direction.

In the drying device18shown inFIG.10, a circumferential substrate transport path along which the film substrate1goes around inside the drying furnace330A is defined. Inside the drying furnace330A, a plurality of pass rollers34are disposed along the substrate transport path.

In addition, a drive roller38is disposed inside the drying furnace330A. The substrate transport path is folded at the position of the drive roller38. Accordingly, the length of the substrate transport path required for the drying of the film substrate1is secured and the drying furnace330A is made compact.

FIG.10shows a configuration in which 32 nozzle units300are dispersively disposed inside the drying furnace330A. The number of nozzle units300disposed inside the drying furnace330A can be appropriately determined in accordance with the length of the substrate transport path, the size of each nozzle unit300, and the like.

The drying device18having such a structure performs a drying process for a printed image that is printed on the film substrate1and that is obtained by superimposing a color image printed by means of aqueous color ink of four colors on a background image printed by means of aqueous white ink, an impermeable medium being applied as the film substrate1.

In a case where a background image is printed by means of white ink, the amount of ink applied to the film substrate1is large in comparison with a case where only a color image is printed and thus there is a problem in reducing power consumption in the drying device18and performing a discharge process or the like.

In a case where a structure described in JP2002-292841A, in which a heater faces a substrate transport path, is applied to the drying device18having a structure shown inFIG.10, the size of a drying module1800in a direction orthogonal to the substrate transport surface may be increased and the size of the drying furnace330A may be increased.

On the other hand, in the drying device18according to the present embodiment, the heater unit320is disposed at a position that does not face the substrate transport surface. Accordingly, an increase in size of the drying furnace330A in the direction orthogonal to the substrate transport surface is prevented.

In addition, in the case of the drying module1800shown inFIG.10, an increase in size of the drying module1800is prevented also in the substrate transport direction. That is, in the case of the drying module1800, the heater unit320is not disposed at a position adjacent to the nozzle unit300in the substrate transport direction. Therefore, the distance between the drying modules1804that are adjacent to each other can be relatively shortened and an increase in size of the drying furnace330A in the substrate transport direction is prevented.

Note that any of the drying module1802shown inFIG.6, the drying module1803shown inFIG.7, or the drying module1804shown inFIG.9may be applied as the drying modules1800shown inFIG.10.

FIG.11is a side view of a drying device that shows another example of disposition of drying modules. Note that the drawing shows a part of the substrate transport path in the drying furnace330A shown inFIG.10. An arrow line shown in the drawing represents the substrate transport direction.

The drying modules1800shown inFIG.11are disposed on a side close to the printing surface1A of the film substrate1and on a side close to the substrate support surface1B. Accordingly, a drying process can be collectively performed with respect to the printing surface1A and the substrate support surface1B of the film substrate1.

In such a configuration, the way in which the nozzle units300and the heater units320are disposed in the drying modules1800disposed on the side close to the printing surface1A of the film substrate1is preferably switched at the drying modules1800disposed on the side close to the substrate support surface1B of the film substrate1. In this case, the heater units320can be disposed on the same side in the substrate width direction in the drying furnace330A.

FIG.12is a side view of a drying device that shows a modification example of drying modules. Note that an arrow line shown inFIG.12represents the substrate transport direction.

A nozzle unit3001provided in a drying module1805shown inFIG.12includes a first nozzle disposition surface302A and a second nozzle disposition surface302B. A plurality of nozzles304are disposed at the first nozzle disposition surface302A and the second nozzle disposition surface302B.

In the case of the nozzle unit3001shown inFIG.12, an upper surface of the nozzle unit3001having a rectangular parallelepiped shape is the first nozzle disposition surface302A and a bottom surface thereof is the second nozzle disposition surface302B. That is, one of two surfaces of the nozzle unit3001shown inFIG.12that are parallel to each other is the first nozzle disposition surface302A and the other of the two surfaces is the second nozzle disposition surface302B.

The first nozzle disposition surface302A and the second nozzle disposition surface302B are not limited to surfaces parallel to each other and surfaces orthogonal to each other may be applied as the first nozzle disposition surface302A and the second nozzle disposition surface302B. Examples of a configuration in which surfaces orthogonal to each other are applied include a configuration in which the first nozzle disposition surface302A is an upper surface of a rectangular parallelepiped and the second nozzle disposition surface302B is a side surface of the rectangular parallelepiped.

According to such a modification example, the heated gas can be blown in a plurality of directions from one nozzle unit3001. Note that, the nozzle disposition surfaces are not limited to two surfaces and three or more surfaces of a polyhedron may serve as the nozzle disposition surfaces.

Referring again toFIG.10, in a case where a plurality of drying modules1800are disposed in the substrate transport direction, a region on an upstream side in the substrate transport direction is a constant rate drying section in which the amount of water evaporation is relatively large and a humidity is likely to rise. Therefore, the volume of the outside air taken into the heated gas generation box360B via the third intake port380shown inFIG.9is relatively large.

Meanwhile, a region on a downstream side in the substrate transport direction is a falling rate drying section in which the amount of water evaporation is relatively small and a humidity is not likely to rise. Therefore, the volume of the outside air taken into the heated gas generation box360B via the third intake port380is relatively small.

That is, the volume per unit period of a gas passing through the third intake port380in the drying module1800disposed at a position on the downstream side in the substrate transport direction is smaller than the volume per unit period of a gas passing through the third intake port380in the drying module1800disposed at a position on the upstream side in the substrate transport direction.

Examples of the region on the upstream side in the substrate transport direction include a region extending from a starting point which is a position at which transport of the film substrate1in the drying device18is started to a position that is separated from the starting point by a distance of 15% or more and 20% or less of the total length of the substrate transport path.

Examples of the region on the downstream side in the substrate transport direction include a region extending from the position that is separated from the starting point by a distance of 15% or more and 20% or less of the total length of the substrate transport path to a position at which the transport of the film substrate1in the drying device18ends.

Actions and Effects of Drying Device According to Embodiments

With the drying device according to the embodiments, it is possible to achieve the following actions and effects.

The nozzle unit300that blows the heated gas to the film substrate1is disposed at a position facing the substrate transport surface. The heater unit320that supplies the heated gas to the nozzle unit300is disposed at a position that does not face the substrate transport surface. Accordingly, an increase in size of the drying module in a direction facing the substrate transport surface is suppressed.

The drying module1801is disposed inside the drying furnace330. Accordingly, it is possible to realize a reduction in heat loss.

The nozzle unit300is disposed inside the drying furnace330A and the heater unit320is disposed outside the drying furnace330A. Accordingly, it is easy to perform maintenance of the axial fan324or the like provided in the heater unit320.

The heater unit320is disposed inside the heated gas generation box360. Accordingly, the axial fan324can blow the heated gas in the heated gas generation box360to the nozzle unit300without escape of thermal energy generated by the heater unit320from the heated gas generation box360.

The heated gas generation box360includes the first intake port362through which outside air is taken in. Accordingly, the heater unit320can generate the heated gas by using air outside the heated gas generation box360.

The heated gas recovery unit370that recovers the heated gas released from the nozzle unit300is provided. In the case of the heated gas recovered to the heated gas recovery unit370, the heated gas is recovered to the heated gas generation box360A via the heated gas discharge port372and the second intake port364. Accordingly, thermal energy circulation in which a high-temperature heated gas in the drying furnace330A is recovered to the heated gas generation box360A is realized and it is possible to achieve a power saving effect with the drying module1803.

The heated gas recovery port376is divided into the plurality of intake regions in a medium width direction. The heated gas recovery unit370includes a plurality of intake flow channels respectively connected to the plurality of intake regions. The plurality of intake flow channels are respectively connected to a plurality of discharge regions into which the heated gas discharge port372is divided. Accordingly, the heated gas recovery unit370can take in the heated gas uniformly in the substrate width direction.

The heated gas generation box360B includes the third intake port380through which outside air is taken in. Accordingly, with the drying module1804, it is possible to suppress a decrease in drying efficiency that is caused by an increase in humidity inside the heated gas generation box360B.

The heated gas generation box360B includes the opening area adjustment mechanism382that adjusts the opening area of the third intake port380. Accordingly, the heated gas generation box360B can adjust the volume of outside air sucked thereinto.

The heated gas generation box360B includes at least one of a temperature sensor or a humidity sensor near the second intake port364. Accordingly, the opening area of the third intake port380can be adjusted in accordance with at least any one of the temperature or the humidity of a gas flowing into the heated gas generation box360B via the second intake port364.

In a case where a plurality of drying modules1800are disposed in the substrate transport direction, at the drying module1800disposed at a position on the upstream side in the substrate transport direction, the volume of outside air taken in via the third intake port380is relatively large in comparison with the drying module1800disposed at a position on the downstream side in the substrate transport direction. Accordingly, the drying efficiency of the entire drying device18can be improved.

The drying module1800is disposed on a side close to the substrate support surface1B of the film substrate1. Accordingly, a drying process can be performed on the film substrate1from the side close to the substrate support surface1B of the film substrate1.

In the case of the nozzle unit3001configured in the form of a polyhedron, the nozzles304are disposed at a plurality of surfaces such as the first nozzle disposition surface302A and the second nozzle disposition surface302B. Accordingly, it is possible to blow the heated gas in a plurality of directions.

Specific Example of Material Applied to Nozzle Unit

Regarding the drying device18, a drying process temperature is changed in accordance with the material of the film substrate1, the thickness of the film substrate1, and an image to be printed on the film substrate1. The thermal responsiveness of the nozzle unit300shown inFIG.4and the like may be decreased in a case where the thickness of a material applied thereto is relatively large and in a case where the heat capacity of a material applied thereto is relatively large.

As the nozzle unit300shown inFIG.4and the like, a metal housing having a rectangular parallelepiped shape and a hollow structure is applied. Accordingly, a certain thermal responsiveness of the nozzle unit300in the case of a change in drying process temperature is secured and thus a waiting time in the case of a change in drying process temperature can be shortened.

That is, a material applied to the nozzle unit300is preferably a metal material having a smaller heat capacity in the viewpoint of ensuring a certain thermal responsiveness. Examples of the metal material applied to the nozzle unit300include iron, stainless steel, and the like.

The nozzle unit300is preferably formed of one kind of metal material and is preferably formed by applying bending processing and welding to a metal plate as a processing method. In the viewpoint of two-dimensionally dispersively disposing the plurality of nozzles304at the nozzle disposition surface302, it is preferable that a material having a certain thickness and having both of workability and stiffness is applied to the nozzle unit300.

The point of the nozzle unit300is to make the volume of the housing as small as possible in the viewpoint of reducing the heat capacity. Meanwhile, in a case where the heated gas flows into the nozzle unit300has a rectangular parallelepiped shape through a surface parallel to the nozzle disposition surface302, the volume per unit period of the heated gas supplied to the nozzles304at positions separated from a heated gas inflow port is decreased with respect to the nozzles304at positions facing the heated gas inflow port and thus blowing the heated gas uniformly may become difficult. The influence of blowing distribution is great in the longitudinal direction of the nozzle unit300in comparison with the lateral direction thereof.

Although it is possible to suppress the blowing distribution of the heated gas by making the distance between a heated gas inflow surface and the nozzle disposition surface302relatively large, the heat capacity of the entire nozzle unit300is relatively increased in this case.

Although it is possible to suppress the blowing distribution of the heated gas by disposing a regulation member such as a rectifying plate in the nozzle unit300, the internal structure of the nozzle unit300may become complicated and there may be an increase in flow channel resistance in the nozzle unit300in this case.

With regard to this, as shown inFIG.4and the like, the heated gas inflow port308is disposed at the side surface306of the nozzle unit300that is orthogonal to the nozzle disposition surface302. Accordingly, the height of the nozzle unit300is suppressed to be small and the blowing distribution of the heated gas is suppressed in the longitudinal direction of the nozzle unit300.

FIG.13is a table that shows evaluation results related to the thickness of a metal plate applied to the nozzle unit.FIG.13shows the evaluation results obtained through evaluation that is performed in the viewpoints of workability, pressure loss, and thermal responsiveness by using the thickness of the metal plate as a parameter.

In the table shown inFIG.13, an evaluation result “A” means “optimum”. An evaluation result “B” means “appropriate”. An evaluation result “C” means “conditionally appropriate”. An evaluation result “D” means “inappropriate”. The same applies to the table shown inFIG.14.

Regarding the workability, in a case where the thickness is smaller than 1.5 mm, processing accuracy may decrease because of a lack of rigidity of the metal plate itself. Therefore, in the viewpoint of workability, the thickness of the metal plate is preferably equal to or larger than 1.5 mm

In addition, in a case where the thickness of the metal plate exceeds 3.5 mm, the difficulty of processing may be relatively high in a case of securing a certain processing accuracy while forming the nozzles304each having a diameter smaller than 100 micrometers. Therefore, the thickness of the metal plate is preferably equal to or smaller than 3.5 mm

The pressure loss is determined based on the volume per unit period of the heated gas blown from the nozzles304. As an index value of the pressure loss, a value measured by an anemometer disposed at a position separated from the positions of the nozzles304by a certain distance may be applied. In a case where the thickness of the metal plate is relatively large, the flow channel resistance in each nozzle304is relatively increased and the pressure loss inside the nozzle unit300is relatively increased.

For example, a wind speed may be measured at a plurality of positions on the nozzle disposition surface302in a state where the output such as the duty of the axial fan324is made constant and the arithmetic mean value of values measured at the positions may be used as an index value of the pressure loss. Examples of the plurality of positions include four corners of the nozzle disposition surface302and the center of the nozzle disposition surface.

That is, regarding the pressure loss, in a case where the thickness of the metal plate is equal to or larger than 3.5 mm, a decrease in heated gas blowing pressure may be caused by an increase in flow channel resistance in the nozzles304. Therefore the thickness of the metal plate being equal to or larger than 3.5 mm is appropriate under certain drying conditions. Meanwhile, the thickness of the metal plate being smaller than 3.5 mm is optimum or appropriate.

The thermal responsiveness is determined based on the length of a period between a time at which a change in temperature settings of the heater unit320is made and a time at which the temperature of the heated gas blown from the nozzles304reaches a prescribed temperature. In a case where the thickness of the metal plate is relatively large, the heat capacity of the nozzle unit300is relatively increased and the thermal responsiveness may be relatively decreased. That is, regarding the thermal responsiveness, in a case where the thickness is equal to or larger than 3.5 mm, a decrease in thermal responsiveness may be caused by an increase in heat capacity in the nozzles304. Therefore, the thickness being equal to or larger than 3.5 mm is appropriate under certain drying conditions. Meanwhile, the thickness of the metal plate being smaller than 3.5 mm is optimum or appropriate.

The “comprehensive determination” in the table shown inFIG.13represents an evaluation result made based on a comprehensive consideration of the workability, the pressure loss, and the thermal responsiveness. In a case where the thickness is smaller than 1.5 mm, the result of the comprehensive determination is “inappropriate” and in a case where the thickness is equal to or larger than 1.5 mm and smaller than 2.0 mm, the result of the comprehensive determination is “optimum”.

In addition, in a case where the thickness is equal to or larger than 2.0 mm and smaller than 3.5 mm, the result of the comprehensive determination is “appropriate” and in a case where the thickness is equal to or larger than 3.5 mm, the result of the comprehensive determination is “conditionally appropriate”.

That is, the thickness of the metal plate applied to the nozzle unit300is preferably equal to or larger than 1.5 mm, more preferably equal to or larger than 1.5 mm and smaller than 3.5 mm. The thickness of the metal plate is still more preferably equal to or larger than 1.5 mm and smaller than 2.5 mm

Specific Example of Structure Applied to Nozzle Unit

In order for the nozzle unit300to uniformly jet the heated gas from all of the nozzles304, the heated gas needs to be stored in the nozzle unit300. That is, the nozzle unit300has a structure in which the opening area of the heated gas inflow port308is equal to or smaller than one times a total nozzle area, which is calculated as the sum of the opening areas of all of the nozzles304.

FIG.14is a table that shows evaluation results related to a structure applied to the nozzle unit.FIG.14shows the evaluation results obtained through evaluation that is performed in the viewpoints of pressure loss and wind speed unevenness. The area ratio in the table shown inFIG.14represents the ratio of the opening area of the heated gas inflow port308to the total nozzle area.

As with the evaluation related to the thickness of the metal plate, the pressure loss is determined based on the volume per unit period of the heated gas blown from the nozzles304and a value measured by an anemometer disposed at a position separated from the positions of the nozzles304by a certain distance may be applied as an index value of the pressure loss. As the position separated from the positions of the nozzles304by a certain distance, the position of the substrate transport surface may be applied.

Regarding the pressure loss, in a case where the area ratio is smaller than 0.1, the opening area of each nozzle304becomes relatively small and there is an increase in pressure loss caused by an increase in flow channel resistance in each nozzle304. Therefore, the area ratio being smaller than 0.1 is inappropriate. In addition, the area ratio being equal to or larger than 0.1 and smaller than 0.4 is conditionally appropriate. Furthermore, regarding the pressure loss, the area ratio being equal to or larger than 0.4 and smaller than 0.7 is appropriate and the area ratio being equal to or larger than 0.7 is optimum.

The wind speed unevenness is determined based on whether or not the wind speeds of the heated gases blown from all of the nozzles304fall within a prescribed range. For example, regarding an index value of the wind speed unevenness, wind speeds at a plurality of positions in the longitudinal direction of the nozzle unit300may be used as the index value. As the plurality of positions, a plurality of positions used for derivation of the index value of the pressure loss may be adopted.

Regarding the wind speed unevenness, the area ratio being smaller than 0.1 is optimum and the area ratio being equal to or larger than 0.1 and smaller than 0.7 is appropriate. In addition, regarding the wind speed unevenness, the area ratio being equal to or larger than 0.7 and smaller than 1.0 is conditionally appropriate. Meanwhile, the area ratio exceeding 1.0 is inappropriate.

The “comprehensive determination” in the table shown inFIG.14represents an evaluation result made based on a comprehensive consideration of the pressure loss and the wind speed unevenness. The area ratio being less than 0.1 and the area ratio exceeding 1.0 are inappropriate and the area ratio being equal to or greater than 0.1 and smaller than 0.4 and the area ratio being equal to or greater than 0.7 and equal to or smaller than 1.0 are appropriate. In addition, the area ratio being equal to or larger than 0.4 and smaller than 0.7 is optimum.

That is, the ratio of the opening area of the heated gas inflow port308to the total nozzle area of the nozzle unit300is preferably equal to or larger than 0.1 and equal to or smaller than 1.0 and more preferably equal to or larger than 0.4 and smaller than 0.7.

About Terms

The term “pre-coating liquid” has the same meaning as terms such as “pretreatment liquid” and “treatment liquid” and is a general term for liquid applied before printing. The pre-coating liquid is an example of coating liquid.

The term “printing apparatus” has the same meaning as terms such as “printing machine”, “printer”, “character printing apparatus”, “image recording apparatus”, “image forming apparatus”, “image output apparatus”, and “drawing apparatus”. The term “image” should be interpreted in a broad sense and includes a color image, a black-and-white image, a single-color image, a gradation image, a uniform density image, and the like.

The term “printing” includes the concepts of terms such as “image recording”, “image formation”, “character printing”, “drawing” and “printing”. The term “device” can include the concept of a system.

The term “image” is not limited to a photographic image, but is used as a comprehensive term including a drawing pattern, a character, a symbol, a line art, a mosaic pattern, a color-coded pattern, various other patterns, and an appropriate combination thereof. Further, the term “image” may include the meaning of an image signal and image data indicating an image.

Regarding the embodiment of the present invention described above, the constituent requirements can be appropriately changed, added, or deleted without departing from the spirit of the present invention. The present invention is not limited to the embodiment described above, and various modifications can be made by a person having ordinary knowledge in the art within the technical idea of the present invention. In addition, the embodiment, the modification examples, and an application example may be combined with each other as appropriate.

EXPLANATION OF REFERENCES