Patent Publication Number: US-10759194-B2

Title: Drying device and ink-jet printing device equipped with the same

Description:
TECHNICAL FIELD 
     The present invention relates to a drying device and an ink-jet printing device equipped with the same, and more specifically, concerns a drying device for drying a printed object printed by a printing part and an ink-jet printing device equipped with the same. 
     BACKGROUND ART 
     A printing device for carrying out printing on a printing object, such as paper, film, cloth or the like, has been known. 
     In general, such printing is carried out by applying an ink containing a coloring agent and an aqueous solvent onto a printing object so that a printed object is formed. For this reason, the printed object immediately after the printing process is in a wet state containing the aqueous solvent, and the corresponding aqueous solvent needs to be removed from the printed object. 
     In the printed object immediately after the printing process from which the aqueous solvent needs to be removed as described above, when much time is required for removing the aqueous solvent, bleeding of ink onto the printing object due to insufficient drying of ink, flocculation of ink, mixed color with an ink having another color, retransferring to the printing object caused by an ink transferring process from a contact member to the printing surface and the like tend to occur, thereby causing a problem of degradation in image quality. Therefore, as the printing device, such a printing device provided with a drying device has been developed so as to dry the printed object immediately after the printing process. 
     For example, an ink-jet recording device (for example, see Patent Literature 1), which is an ink-jet recording device capable of continuously recording on the two surfaces of a web, and provided with a plurality of recording heads installed therein, a drying device for drying the web on which a recording was made by the recording head and guide rollers for guiding the web, and another ink-jet recording device (for example, see Patent Literature 2), which is provided with a line head disposed on the recording surface side of a web, guide rollers for guiding the web, a suction mechanism disposed on the non-recording surface side of the web, and a drying device for drying the web on which the recording was made by the recording head, have been known. 
     Moreover, a method for constituting a liquid coating device (for example, see Patent Literature 3), which includes steps of providing a drying unit including a liquid coating unit having a first transporting part for transporting a medium and a liquid coating part for applying a liquid onto the medium transported by the first transporting device, a second transporting part for transporting the medium onto which the liquid is applied by the liquid coating part and a drying unit for drying the liquid applied onto the medium, with the drying unit being designed so that by controlling the second transporting part, a tension to be applied to the medium inside the drying unit can be controlled, has been known in which in the case when a transporting path of a medium is formed between the liquid coating unit and the drying unit by connecting the liquid coating unit and the drying unit, or in the case when a transporting path of a medium is formed between the two drying units by connecting the two drying units, an adjusting part between the connected two units is provided so that the transporting operation of the medium in one of the units and the transporting operation of the medium in the other unit are independently controlled, and the number of the drying units to be provided in the liquid coating device is determined depending on the kinds of media to be transported. 
     CITATION LIST 
     Patent Literature 
     PTL 1: Japanese Patent Application Laid-Open No. 2012-116019 
     PTL 2: Japanese Patent Application Laid-Open No. 2013-18247 
     PTL 3: Japanese Patent Application Laid-Open No. 2016-107549 
     SUMMARY OF INVENTION 
     Technical Problem 
     However, in the case of a drying machine installed in the ink-jet printing device described in Patent Literatures 1 and 2, since the drying time is comparatively short, it is necessary to make the setting temperature of the drying machine extremely high in order to sufficiently dry the printed object. 
     Moreover, in the case when the setting temperature of the drying machine is made extremely high, although the printed object is dried sufficiently, the temperature of the printed object is raised abruptly, with the result that the printed object itself might be curled, or wrinkles and cockling might occur in the printed object. Additionally, the cockling refers to a state in which the printed object is curved like waves. 
     Furthermore, in the liquid coating device described in Patent Literature 3, two drying units are installed; however, since the transporting speed is made two times faster correspondingly, it is not possible to suppress the abrupt temperature rise of the printed object as a result. Therefore, it cannot be said that it becomes possible to sufficiently suppress curling of the printed object itself or wrinkles and cockling from occurring in the printed object. 
     In view of the above-mentioned circumstances, the present invention has been devised, and its object is to provide a drying device capable of drying the printed object as well as sufficiently suppressing curling of the printed object itself or wrinkles and cockling from occurring in the printed object. 
     Solution to Problems 
     As a result of earnest study made by the present inventors, etc. in view of solving the above-mentioned problems, they have found that upon drying a printed object, it is necessary to take two stages of processes, that is, sufficiently heating the wet printed object and then applying sufficient evaporation energy to the aqueous solvent. 
     Moreover, they have found that by forming a configuration in which the printed object is heated step by step by using a first heating roller part and a first heating part, as well as a second heating roller part and a second heating part, the above-mentioned problems can be solved so that the present invention has been completed. 
     The present invention, which relates to a drying device which (1), while transporting a long-sized printed object to which an ink was applied by a printing part, the printed object is dried, is provided with a first heating roller part and a second heating roller part that guide the printed object and can also heat the printed object, a first heating part installed so as to be opposed to the outer circumferential surface of the first heating roller part, and a second heating part installed so as to be opposed to the outer circumferential surface of the second heating roller part, and the resulting drying device is designed so that after the printed object has been guided to the first heating roller part on the upstream side, it is guided to the second heating roller part on the downstream side, with the setting temperature of the second heating roller part being made higher than the setting temperature of the first heating roller part. 
     The present invention, which relates to the drying device described in the above-mentioned (1) in which (2) the first heating part is constituted by a plurality of first hot air blowing devices that are installed side by side along a circumferential direction of the first heating roller part, and the second heating part is constituted by a plurality of second hot air blowing devices that are installed side by side along a circumferential direction of the second heating roller part, and gaps are formed between the printing surface of the printed object and the first hot air blowing devices as well as between the printing surface of the printed object and the second hot air blowing devices so that the first hot air blowing devices and the second hot air blowing devices are respectively allowed to blow hot air toward the printing surface of the printed object. 
     The present invention relates to the drying device described in the above-mentioned (2) in which (3) a gap is formed between the mutually adjacent first hot air blowing devices and a gap is formed between the mutually adjacent second hot air blowing devices. 
     The present invention relates to the drying device described in any one of the above-mentioned (1) to (3) which is further provided with (4) an auxiliary heating part that is formed on an upper stream side than a position at which the rear surface of the printed object is made to contact with the first heating roller part, and the auxiliary heating part is constituted by auxiliary hot air blowing devices installed along the transporting path of the printed object, with a gap being formed between the printing surface of the printed object and the auxiliary hot air blowing devices, so that the auxiliary hot air blowing devices are capable of blowing the hot air toward the printing surface of the printed object. 
     The present invention relates to the drying device described in any one of the above-mentioned (1) to (4) in which (5) the second heating roller part and the second heating part are housed in a chamber provided with an exhaust opening. 
     The present invention relates to the drying device described in the above-mentioned (5) which is further provided with (6) a quick cooling roller that guides the printed object and is also capable of cooling the printed object, and the quick cooling roller is disposed closely to the second heating roller part so that the printed object ejected out of the chamber is directly guided from the second heating roller part to the quick cooling roller. 
     The present invention relates to the drying device described in the above-mentioned (6) which is further provided with (7) a cooling roller that guides the printed object and is also capable of cooling the printed object, and the cooling roller is disposed on the downstream side of the quick cooling roller so that after the printed object has been guided to the quick cooling roller, it is further guided to the cooling roller. 
     The present invention relates to an ink-jet printing device that is provided with (8) a printing part which, while transporting a printing object, carries out a printing process on the printing object, and a drying device described in any one of the above-mentioned (1) to (7) which, while transporting a long-sized printed object that was printed by the printing part, dries the printed object, and the printing part is constituted by a plurality of ink-jet printing heads. 
     Advantageous Effects of Invention 
     In the drying device of the present invention, since the first heating roller part and the second heating roller part are installed, the drying time relative to the printed object to be transported can be made sufficiently longer. 
     Moreover, by heating the two sides of the printed object by using the first heating roller part and the first heating part as well as the second heating roller part and the second heating part, the printed object can be efficiently dried. 
     At this time, in the drying device of the present invention, since the setting temperature of the second heating roller part is higher than the setting temperature of the first heating roller part, the wet printed object is sufficiently heated by the first heating roller part and the first heating part whose setting temperatures are comparatively low, and to the aqueous solvent, a sufficient evaporation energy can be applied by the second heating roller part and the second heating part whose setting temperatures are comparatively high. Additionally, by adding sufficient evaporation energy thereto, the aqueous solvent is evaporated to be removed from the printed object. 
     In this manner, in the drying device of the present invention, since the wet printed object immediately after the printing process can be heated step by step, the printed object can be positively dried, and it becomes possible to sufficiently suppress curling of the printed object itself or wrinkles and cockling from occurring in the printed object. 
     In this case, the setting temperature of the first heating roller part is desirably made the boiling point or less of the aqueous solvent contained in the ink. That is, in the first heating roller part, heating of the printed object is more preferentially carried out in comparison with the evaporation of the aqueous solvent. Thus, it becomes possible to positively prevent the temperature of the printed object from being abruptly raised. 
     In the drying device of the present invention, since the plural first hot air blowing devices are installed side by side along the circumferential direction of the first heating roller part as the first heating part, and since the plural second hot air blowing devices are installed side by side along the circumferential direction of the second heating roller part as the second heating part, the hot air can be blown to the printed object without irregularities. Thus, the printed object is suppressed from having partial differences in the drying speed and can be more uniformly dried. 
     At this time, it is more desirable to set a gap between the adjacent first hot air blowing devices as well as between the adjacent second hot air blowing devices. In this case, the hot air blown toward the printed object can be released through the gap. Thus, since a convection current of the hot air blown thereto is generated, it is possible to prevent the hot air containing the aqueous solvent from being stagnated on the periphery of the printed object. 
     In the drying device of the present invention, since the auxiliary heating part constituted by an auxiliary hot air blowing device is further installed, the printing surface side of the printed object can be preliminarily heated before the printed object has been made to contact with the first heating roller part. Additionally, since an ink was applied to the printing surface side of the printed object, this side is inferior to the rear surface side in heating efficiency. For this reason, by preliminarily heating the printing surface side of the printed object, the entire printed object can be more uniformly dried more efficiently. 
     In the drying device of the present invention, since the second heating roller part and the second heating part are housed in the chamber provided with an exhaust opening, the evaporated aqueous solvent can be held inside the chamber and also exhausted from the exhaust opening of the chamber. Thus, it is possible to prevent the evaporated aqueous solvent from floating and re-adhering to the printed object, or from adhering to the drying device. 
     In the drying device in the present invention, since the quick cooling roller to be installed closely to the second heating roller part is provided, the printed object ejected outside the chamber is quickly cooled by the quick cooling roller to which it is directly guided from the second heating roller part; therefore, the evaporation of the aqueous solvent in the printed object is forcefully stopped. Thus, the evaporated aqueous solvent is suppressed from being discharged outside of the chamber. 
     In the drying device in the present invention, since the cooling roller disposed on the downstream side of the quick cooling roller is provided, the printed object can be sufficiently cooled. 
     Thus, in the case when the printed object is collected by winding-up or the like, it becomes possible to suppress the dimensional changes of the printed object at the time of winding-up as much as possible. 
     Moreover, in the case when, not limited by winding-up, a post-processing device is connected, less influences are given to the post-processing device. 
     Furthermore, by returning the temperature of the printed object to that prior to the drying process, another printing process can be carried out on the rear surface of the printed object. 
     Furthermore, troubles, such as an expansion of the roller on the downstream side, etc., can be suppressed. 
     In the ink-jet printing device of the present invention, since the above-mentioned drying device is installed, a printed object on which printing processes were carried out by a plurality of ink-jet printing heads can be dried immediately after the printing processes, and it also becomes possible to sufficiently suppress curling of the printed object itself or wrinkles and cockling from occurring in the printed object. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a perspective side view schematically showing one embodiment of a drying device in accordance with the present invention. 
         FIG. 2  is a horizontal cross-sectional view showing a first heating roller part of the drying device in accordance with the present embodiment. 
         FIG. 3(A)  is an oblique perspective view showing a first hot air blowing device of the drying device in accordance with the present embodiment. 
         FIG. 3(B)  is a top face view showing a sheath heater of the first hot air blowing device shown in  FIG. 3(A) . 
         FIG. 3(C)  is a cross-sectional view taken along line A-A of the first hot air blowing device shown in  FIG. 3(A) . 
         FIG. 3(D)  is a bottom view showing the first hot air blowing device shown in  FIG. 3(A) . 
         FIG. 4  is a perspective side view showing the drying device of  FIG. 1  seen from an opposite side. 
         FIG. 5  is a vertical cross-sectional view taken along a width direction of a quick cooling roller of the drying device in accordance with the present embodiment. 
         FIG. 6  is a vertical cross-sectional view taken along a width direction of a cooling roller of the drying device in accordance with the present embodiment. 
         FIG. 7  is a perspective side view schematically showing one embodiment of an ink-jet printing device in accordance with the present invention. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Referring to the Figures, the following description will discuss preferred embodiments of the present invention in detail. Additionally, in the drawings, the same components are indicated by the same reference numerals, and the overlapping descriptions will be omitted. Moreover, the positional relationship, such as upper, lower, left or right side, is based upon the positional relationship shown in the Figure, unless otherwise particularly specified. Furthermore, dimensional ratios of the Figures are not intended to be limited by the dimensional ratios shown in Figures. 
     First, an explanation will be given to a drying device in accordance with the present invention. 
     The drying device in accordance with the present invention is a device which dries a long-sized printed object corresponding to the printing object onto which an ink was applied by a printing part, while being transported. 
     The drying device may be used by being installed in a printing device, or may be continuously used by being installed in parallel with the printing device. 
     In this case, as the above-mentioned printing object, long-sized paper, film, cloth or the like may be adopted. 
     As the above-mentioned ink, although not particularly limited, an ink containing a colorant, such as dye, pigment or the like, an aqueous solvent and known additives to be added thereto on demand, may be used. 
     As the above-mentioned printing device, an ink-jet printing device, an offset printing device, a gravure printing device, a flexographic printing device, a screen printing device and the like may be adopted. 
     Additionally, in the present specification, “upstream side” means the upstream side in the transporting path of the printed object, and “downstream side” means the downstream side in the transporting path of the printed object. That is, the first heating roller part side is set to be the upstream side, and the second heating roller part side is set to be the downstream side. 
     Moreover, “printing surface” means a surface on the side where the ink for the printed object is applied, and “rear surface” means a surface on the side opposite to the printing surface. 
     Furthermore, “width direction” means a direction orthogonal to the transporting direction of the printed object. 
       FIG. 1  is a perspective side face view schematically showing one embodiment of a drying device in accordance with the present invention. Additionally, illustration of an exhaust opening  15   a  to be described later is omitted therefrom. 
     As shown in  FIG. 1 , a drying device H in accordance with the present embodiment is provided with: a heating roller part  10  (hereinafter, referred to as “first heating roller part”) and a heating roller part  20  (hereinafter, referred to as “second heating roller part”) that guide a printed object X and are capable of heating the printed object X; a heating part  11  (hereinafter, referred to as “first heating part”) that is formed so as to be opposed to the outer circumferential surface of the first heating roller part  10  and a heating part  21  (hereinafter, referred to as “second heating part”) that is formed so as to be opposed to the outer circumferential surface of the second heating roller part  20 ; a chamber  15  (hereinafter, referred to as “first chamber”) in which the first heating roller part  10  and the first heating part  11  are housed; a chamber  25  (hereinafter, referred to as “second chamber”) in which the second heating roller part  20  and the second heating part  21  are housed; an auxiliary heating part  50  installed on an upper stream side than a position where the rear surface of the printed object X is made in contact with the first heating roller part  10 ; a quick cooling roller  30  that guides the printed object X and is also capable of cooling the printed object X; and a cooling roller  40  that guides the printed object X and is also capable of cooling the printed object X. 
     In the drying device H, the printed object X onto which an ink was applied from a printing part, not shown, is successively guided by the first heating roller part  10 , the second heating roller part  20 , the quick cooling roller  30  and the cooling roller  40 . Additionally, the printed object X that is dried after having been guided by the cooling roller  40  is guided, for example, to a collecting part, not shown, and collected in the collecting part by using a so-called, winding-up system or folding-up system. Alternatively, the printed object X that is dried after having been guided by the cooling roller  40  is guided, for example, to a printing part of another printing device so that the rear surface of the printed object is again printed. 
     In the drying device H, the printed object X is heated by the first heating roller part  10  and the first heating part  11  as well as the second heating roller part  20  and the second heating part  21 , while being guided by these, and also cooled by the quick cooling roller  30  and the cooling roller  40 . 
     In this manner, in the drying device H, since the printed object X is dried while being guided by the first heating roller part  10  and the second heating roller part  20 , the drying time for the printed object X can be made sufficiently longer. 
     Moreover, since both of the two sides of the printed object X can be heated by the first heating roller part  10  and the first heating part  11  as well as the second heating roller part  20  and the second heating part  21 , it becomes possible to efficiently dry the printed object X. 
     First, the printed object X to which the ink was applied is guided by guide rollers, and heated and dried by the auxiliary heating part  50 . 
     In the drying device H, the auxiliary heating part  50  is formed on the printing surface side of the printed object X on an upper stream side than a position at which the rear surface of the printed object X is made in contact with the first heating roller part  10 , along the printed object X. 
     In the drying device H, prior to the arrival of the printed object X with an ink applied thereto to the first heating roller part  10 , the printing surface that is wetter than the rear surface of the printed object X is preliminarily heated by the auxiliary heating part  50 . Thus, in the printed object X, differences in the drying speeds between the printing surface and the rear surface of the printed object X caused by the first heating roller part  10  and the first heating part  11  as well as the second heating roller part  20  and the second heating part  21  to be described later can be made smaller as much as possible. As a result, the printed object X as a whole can be more efficiently dried more uniformly. 
     The auxiliary heating part  50  is constituted by an auxiliary hot air blowing device  51  installed along the transporting path of the printed object X. Additionally, the auxiliary hot air blowing device  51  is supported by a frame, not shown, attached to a box part HA of the drying device H. 
     The auxiliary hot air blowing device  51  is allowed to blow hot air to the printed object X. That is, there is a gap between the printing surface of the printed object X and the auxiliary hot air blowing device  51  so that the auxiliary hot air blowing device  51  can blow hot air toward the printing surface of the printed object X. 
     The shortest distance between the printed object X and the auxiliary hot air blowing device  51  is desirably set from 5 mm to 10 mm, in the same manner as in the shortest distance H 1  between the outer circumferential surface of the first heating roller part  10  and the first hot air blowing device  14 , which will be described later. 
     As the auxiliary hot air blowing device  51 , such a device similar to a thermostat or a thermocouple to be described later may be attached. 
     The setting temperature of the auxiliary hot air blowing device  51  is preferably set from 100 to 140° C. 
     Since the structure of the auxiliary hot air blowing device  51  is the same as the structure of a hot air blowing device  14  of the first heating part  11  to be described later, other detailed descriptions thereof will be omitted (see  FIGS. 3(A), 3(B), 3(C) and 3(D) ). Additionally, the auxiliary hot air blowing device  51  is constituted by three blowing units  14   a  (see  FIG. 3(A) ). 
     The printed object X that has passed through the auxiliary heating part  50  is guided by the corresponding first heating roller part  10  in a manner so as to wind around the outer circumferential surface of the first heating roller part  10 . That is, the first heating roller part  10  is designed to guide the printed object X and also to heat the printed object X. 
     At this time, the winding angle θ of the printed object X relative to the heating roller part  10 , that is, the angle θ made by a first line that is formed by connecting a point on the side face of the first heating roller part  10  at which the printed object X is first made in contact with the first heating roller part  10  to the center axis of the first heating roller part  10  and a second line that is formed by connecting a point at which the printed object X is last in contact with the first heating roller part  10  to the center axis of the first heating roller part  10  is preferably set to 180 degrees or more, and more preferably set to 270 degrees or more. In this case, since the drying time is made sufficiently longer, the printed object can be dried at a comparatively low temperature. 
     In the drying device H, the first heating roller part  10  has a hollow column shape whose outer circumferential surface is designed to be heated. For this reason, the printed object X is heated when made in contact with the outer circumferential surface of the first heating roller part  10 . Additionally, in order to prevent a degradation in image quality of the printing surface due to frictional sliding of the printed object X thereon, the first heating roller part  10  is preferably disposed so as to be made in contact with the rear surface of the printed object X. 
       FIG. 2  is a horizontal cross-sectional view showing the first heating roller part of the drying device in accordance with the present embodiment. Additionally, illustration of the first chamber  15  is omitted. 
     As shown in  FIG. 2 , the first heating roller part  10  is provided with a hollow column-shaped drum  12 , a band heater  13  for heating the drum  12  and a shaft core  16  to which the two sides of the drum  12  are attached and fixed. 
     In the first heating roller part  10 , the drum  12  is made of a metal such as aluminum or the like. 
     Moreover, the drum  12  has its outer circumferential surface subjected to irregularity machining, such as sand blasting, shot blasting, beads blasting or the like. Thus, when the rear surface of the printed object X and the outer circumferential surface of the first heating roller part  10  (drum  12 ) are in contact with each other, should there be air intruded into the gap between these, the air could be released from gaps caused by the surface with irregularities, and by further enhancing the grip, the adhesion onto the drum can also be improved. As a result, it is possible to suppress the drying efficiency of the printed object X from being lowered. 
     The band heater  13  has an annular shape, and is attached to the inside of the drum  12  in a manner so as to be set along the inner circumferential surface of the drum  12 . 
     Moreover, three sets of the band heaters  13  are placed side by side relative to the width direction of the drum  12 . 
     In each of the band heaters  13 , a power source terminal  13   a , a thermocouple  13   b  for measuring the temperature of the band heater  13  and a thermostat  13   c  for blocking the power supply to the heater upon the occurrence of an abnormal heating process are attached to the inner circumferential surface thereof. 
     Therefore, each band heater  13  has its temperature settable independently and also has its temperature adjustable. 
     Moreover, for example, in the case when the width of the printed object X is small, the power source for the band heater  13  that is not used can be turned OFF. 
     In this case, the setting temperature of the first heating roller part  10  is adjusted, for example, in a range from 80 to 120° C. The setting temperature is preferably adjusted to 100° C. or less. That is, in the first heating roller part  10 , the heating process of the printed object is more preferentially carried out rather than the evaporation of the aqueous solvent. For this reason, the first heating roller part  10  carries out a heating process, while suppressing the evaporation of the aqueous solvent as much as possible so as not to abruptly raise the temperature of the printed object X. 
     The shaft core  16  is supported by brackets B 1  through bearings, and each bracket B 1  is attached to the box part HA of the drying device H through a frame. For this reason, the first heating roller part  10  is made to be freely rotatable relative to the bracket B 1 . Additionally, the first heating roller part  10  is rotated by a frictional force caused by the transporting of the printed object X to be consequently rotated together with the printed object X. 
     Moreover, to one end of the shaft core  16 , a power source-use rotary connector  16   a  is attached, and to the other end thereof, a signal-use rotary connector  16   b  is attached. 
     Furthermore, each of the aforementioned power source terminals  13   a  is connected to the power source-use rotary connector  16   a  through a cable, and each of the aforementioned thermocouples  13   b  is connected to the signal-use rotary connector  16   b  through a cable. 
     Returning again to  FIG. 1 , in the drying device H, the first heating part  11  is installed so as to be opposed to the outer circumferential surface of the first heating roller part  10 , with the printed object X interposed therebetween. That is, the first heating part  11  is installed with a fixed interval from the printing surface of the printed object X. 
     Therefore, the rear surface of the printed object X is heated by the first heating roller part  10 , while the printing surface thereof is heated by the first heating part  11 . 
     The first heating part  11  is constituted by a plurality of hot air blowing devices  14  (hereinafter, referred to as “first hot air blowing device”) that are aligned side by side along the circumferential direction of the first heating roller part  10 . Additionally, the plural first hot air blowing devices  14  corresponding to the first heating part  11  is supported by the first chamber  15 . 
     The first hot air blowing device  14  is capable of blowing hot air to the printed object X. That is, there is a gap between the printing surface of the printed object X and the first hot air blowing device  14  so that the first hot air blowing device  14  can blow hot air toward the printing surface of the printed object X. Thus, hot air can be blown to the printed object X without irregularities. Moreover, the printed object X is suppressed from partially causing a difference in drying speeds and can be dried more uniformly. 
     In this case, the shortest distance H 1  (see  FIG. 1 ) between the outer circumferential surface of the first heating roller part  10  and the first hot air blowing device  14  is preferably set from 5 mm to 10 mm. 
     In the case when the shortest distance H 1  is set to less than 5 mm, the printed object X might come into contact with the first hot air blowing device  14  (bottom plate  14   a   4 ) in comparison with a case where the shortest distance H 1  is set within the above-mentioned range, and in the case when the shortest distance H 1  exceeds 10 mm, the drying efficiency by the first hot air blowing device  14  tends to be abruptly lowered in comparison with the case where the shortest distance H 1  is set within the above-mentioned range. 
       FIG. 3(A)  is an oblique perspective view showing the first hot air blowing device of the drying device in accordance with the present embodiment;  FIG. 3(B)  is a top view showing a sheath heater of the first hot air blowing device shown in  FIG. 3(A) ;  FIG. 3(C)  is a cross-sectional view taken along line A-A of the first hot air blowing device shown in  FIG. 3(A) ; and  FIG. 3(D)  is a bottom view of the first hot air blowing device shown in  FIG. 3(A) . 
     As shown in  FIG. 3(A) , the first hot air blowing device  14  is constituted by two blowing units  14   a.    
     Moreover, each of the blowing units  14   a  has a hollow rectangular pillar shape that extends in a width direction of the first heating roller part  10  so as to be substantially made coincident with the width of the first heating roller part  10 . For this reason, hot air to be blown from the first hot air blowing device  14  covers the entire width of the first heating roller part  10 . 
     The blowing unit  14   a  is constituted by a bottom plate  14   a   4 , a sheath heater  14   a   1  that is disposed on the bottom plate  14   a   4  so as to form a heating source, a nozzle pipe  14   a   2  capable of blowing air toward the sheath heater  14   a   1 , and a heater cover  14   a   3  installed so as to cover the sheath heater  14   a   1  and the nozzle pipe  14   a   2 . 
     As shown in  FIG. 3(B) , the sheath heater  14   a   1  is bent into a U-letter shape when seen from a top view and electrodes are formed on the ends of the two sides. 
     Since the sheath heater  14   a   1  has a spiral shaped rib part R, its surface area becomes larger. Thus, on the periphery of the sheath heater  14   a   1 , air can be heated with a comparatively large area. 
     As shown in  FIG. 3(C) , since the sheath heater  14   a   1  is the above-mentioned U-letter shape, when cut along line A-A of  FIG. 3(A) , the heaters are installed one row by one row on the upstream side and the downstream side. 
     Moreover, the nozzle pipe  14   a   2  is formed on an upper side between the sheath heaters  14   a   1  on the two sides. 
     Furthermore, the nozzle pipe  14   a   2  is designed such that compressed air is allowed to flow through the inside thereof, and on the lower side of the nozzle pipe  14   a   2 , there are a pair of nozzle holes N formed toward the sheath heaters  14   a   1  on the two sides. In this case, a plurality of the nozzle holes N are formed along the length direction of the nozzle pipe  14   a   2  (see  FIG. 3(A) ). Therefore, air blown from the nozzle holes N is heated by the sheath heaters  14   a   1 . 
     At this time, the diameter of the nozzle hole N is gradually made smaller as it departs from the flow inlet of air of the nozzle pipe  14   a   2 . That is, the air pressure of incoming air becomes greater at the recessed portion that is the furthest from the flow inlet of air of the nozzle pipe  14   a   2 , while the air pressure of incoming air becomes smaller at a portion close to the flow inlet of air of the nozzle pipe  14   a   2 ; therefore, by making the diameter of the nozzle hole N smaller as it comes closer to the recessed portion, the blowing amount of air from each of the nozzle holes N can be made uniform. 
     In the blowing unit  14   a , the sheath heater  14   a   1  and the nozzle pipe  14   a   2  are housed in a space V formed by a bottom plate  14   a   4  and the heater cover  14   a   3  coupled to the bottom plate  14   a   4 . Therefore, the space V is filled with air heated by the sheath heater  14   a   1 . 
     Moreover, a slit S is formed on the bottom plate  14   a   4  so that the heated air, that is, hot air, is blown onto the printed object X from the slit S. 
     Additionally, the width H 2  of the slit S is preferably set from 0.5 mm to 1.0 mm from the viewpoint of the blowing width and the air pressure. 
     As shown in  FIG. 3(D) , in the blowing unit  14   a , a plurality of the slits S are installed so as to extend along the length direction (width direction of the first heating roller part  10 ) of the bottom plate  14   a   4 . Thus, hot air can be blown to the entire width of the first heating roller part  10 . 
     Returning again to  FIG. 1 , in the first heating part  11 , a gap T is formed between the mutual adjacent first hot air blowing devices  14 . Thus, the hot air blown to the printed object X from the slit S of the first hot air blowing device  14  and evaporated aqueous solvent can be released outside through the gap T. As a result, since a convection current of the hot air blown thereto is generated, it is possible to prevent the hot air containing the aqueous solvent from being stagnated on the periphery of the printed object X. 
     Additionally, as the first hot air blowing device  14 , such a device similar to the aforementioned thermostat or thermocouple may be installed. 
     Moreover, the setting temperature of the first hot air blowing device  14  is preferably set to the setting temperature or more of the first heating roller part  10 , and more specifically, more preferably set to a temperature obtained by adding 0 to 20° C. to the setting temperature of the first heating roller part  10 . 
     In the drying device H, the first heating roller part  10  and the first heating part  11  are housed in the first chamber  15 . 
     The first chamber  15  has a box shape having holes corresponding to the drum  12  on the front face (surface side of the paper of  FIG. 1 ) and the rear face (back side of the paper of  FIG. 1 ), and is formed so as not to interfere with the first heating roller part  10  and the first heating part  11 , and also so as to cover them. 
     Moreover, the first chamber  15  has openings at corner portions so as not to interfere with the transporting process of the printed object X. 
     In the drying device H, even if the aqueous solvent of the printed object X is evaporated by the heating process of the first heating roller part  10  and the first heating part  11 , the evaporated solvent can be sufficiently enclosed inside the first chamber  15 . 
     The first chamber  15  has sliding parts P respectively formed on the outer side faces on the upstream side and the downstream side, and is supported on rail parts L formed on the box part HA of the drying device through the sliding parts P. 
     Moreover, the rail parts L extend from the inside of the box part HA rearward (back side of the paper of  FIG. 1 ) of the box part HA through cut-out parts K formed on the box part HA so as to be in parallel with the shaft core direction (width direction) of the first heating roller part  10 . For this reason, the first chamber  15  is allowed to pass through the cut-out parts K from the inside of the box part HA along the rail parts L through the sliding parts P, and is made slidable rearward of the box part HA. Additionally, at this time, the hole of the front face of the first chamber  15  passes through the drum  12 . 
     In the heating device H, by allowing the first chamber  15  to slide rearward of the box part HA, an advantage of easy maintenance can be obtained. 
     Moreover, the first chamber  15  has its inner wall face covered with a heat insulating material, not shown, having a heat insulating property in itself, such as glass wool or the like. For this reason, the first chamber  15  is allowed to exert a so-called heat shielding effect that suppresses heat generated by the first heating roller part  10  and the first heating part  11  from transmitting to the outside of the first chamber  15 . 
       FIG. 4  is a perspective side view showing the drying device of  FIG. 1  viewed from the opposite side. Moreover, in  FIG. 4 , illustration of a pipe coupled to the exhaust opening  15   a  is omitted. 
     As shown in  FIG. 4 , the first chamber  15  has a plurality of exhaust openings  15   a  formed on its side face. Moreover, each of the exhaust openings  15   a  is communicated with an exhaust-use air blower D 1  disposed on the outside of the first chamber  15 . Therefore, by operating the exhaust-use air blower D 1 , air inside the first chamber  15  can be exhausted from exhaust ducts, not shown, on the outside through the exhaust openings  15   a . Thus, in the first chamber  15 , even if the aqueous solvent is evaporated and floating, the aqueous solvent can be removed so that it becomes possible to prevent the floating aqueous solvent from re-adhering to the printed object X by dew condensation or from adhering to the inside of the drying device H to cause contamination. 
     Moreover, inside the first chamber  15 , a supply-use air blower D 2  for supplying air to the aforementioned first heating part  11  is disposed in parallel with the exhaust-use air blower D 1 . Additionally, a supply opening for supplying air to the first heating part  11  is also formed on the first chamber  15 ; however, illustration thereof is omitted because the position of the supply opening and the position of the first heating part  11  overlap with each other. 
     Returning again to  FIG. 1 , in the drying device H, the printed object X that has passed through the first heating roller part  10  on the upstream side is guided to the second heating roller part  20  on the downstream side through a plurality of guide rollers. 
     The second heating roller part  20  has a hollow column shape whose outer circumferential surface is designed to be heated. For this reason, the printed object X is heated when made in contact with the outer circumferential surface of the second heating roller part  20 . Additionally, in order to prevent a degradation in image quality of the printing surface due to frictional sliding of the printed object X thereon, the second heating roller part  20  is preferably disposed so as to be in contact with the rear surface of the printed object X. 
     Additionally, the second heating roller part  20  is supported by brackets B 2 , and each of the brackets B 2  is attached to the box part HA of the drying device H through a frame. 
     Moreover, since the structure of the second heating roller part  20  is the same as the structure of the aforementioned first heating roller part  10 , the other detailed explanations thereof will be omitted (see  FIG. 2 ). 
     In this case, the setting temperature of the second heating roller part  20  is made higher than the setting temperature of the first heating roller part  10 . That is, in the second heating roller part  20 , with respect to the printed object X sufficiently heated by the first heating roller part  10 , the aqueous solvent is evaporated. For this reason, in the second heating roller part  20 , the aqueous solvent is actively evaporated so that the printed object X is positively dried. 
     Additionally, the setting temperature of the second heating roller part  20  is preferably designed in a range from 100 to 140° C. 
     In the drying device H, the second heating part  21  is installed so as to be opposed to the outer circumferential surface of the second heating roller part  20 , with the printed object X interposed therebetween. That is, the second heating part  21  is formed with a fixed interval from the printing surface of the printed object X. 
     Therefore, the printed object X has its rear surface heated by the second heating roller part  20  and also has its printing surface heated by the heating part  21 . 
     The second heating part  21  is constituted by a plurality of hot air blowing devices  24  (hereinafter, referred to as “second hot air blowing device”) that are installed side by side along a circumferential direction of the second heating roller part. Additionally, the second hot air blowing device  24  is supported by the second chamber  25 . 
     The second hot air blowing device  24  is capable of blowing hot air toward the printed object X. That is, there is a gap between the printing surface of the printed object X and the second hot air blowing device  24  so that the second hot air blowing device  24  is capable of blowing hot air toward the printing surface of the printed object X. Thus, hot air can be blown to the printed object X without irregularities. Moreover, the printed object X is suppressed from having partial differences in the drying speed and can be more uniformly dried. 
     In the second heating part  21 , a gap T is formed between mutually adjacent second hot air blowing devices  24 . Thus, the hot air blown toward the printed object X through the slit S of the second hot air blowing devices  24  can be released outside from the gap T. As a result, since a convection current of the hot air blown thereto is generated so that it is possible to prevent the hot air containing the aqueous solvent from being stagnated on the periphery of the printed object X. 
     The shortest distance between the outer circumferential surface of the second heating roller part  20  and the second hot air blowing devices  24  is preferably set from 5 mm to 10 mm, in the same manner as in the shortest distance H 1  between the outer circumferential surface of the above-mentioned first heating roller part  10  and the first hot air blowing device  14 . 
     As the second hot air blowing device  24 , a device similar to the aforementioned thermostat or thermocouple, may be attached. 
     The setting temperature of the second hot air blowing device  24  is preferably set to the setting temperature or more of the second heating roller part  20 , and more specifically, it is more preferably set to a temperature obtained by adding 0 to 20° C. to the setting temperature of the second heating roller part  20 . 
     Additionally, since the structure of the second hot air blowing device  24  is the same as the first hot air blowing device  14  of the aforementioned first heating part  11 , the other detailed explanations thereof will be omitted (see  FIG. 3(A) ,  FIG. 3(B) ,  FIG. 3(C)  and  FIG. 3(D) ). 
     In the drying device H, the second heating roller part  20  and the second heating part  21  are housed in the second chamber  25  (chamber). 
     The second chamber  25  has a box shape having holes corresponding to the drum  12  on the front face (surface side of the paper of  FIG. 1 ) and the rear face (back side of the paper of  FIG. 1 ), and is formed so as not to interfere with the second heating roller part  20  and the second heating part  21 , and also so as to cover these. 
     Moreover, the second chamber  25  has openings at corner portions so as not to interfere with the transporting process of the printed object X. 
     In the drying device H, even if the aqueous solvent of the printed object X is evaporated by the heating process of the second heating roller part  20  and the second heating part  21 , the evaporated solvent can be sufficiently enclosed inside the second chamber  25 . 
     The second chamber  25  has sliding parts P respectively formed on the outer side faces on the upstream side and the downstream side, and is supported on rail parts L formed on the box part HA of the drying device through the sliding parts P. 
     Moreover, the rail parts L extend from the inside of the box part HA rearward (back side of the paper of  FIG. 1 ) of the box part HA through cut-out parts K formed on the box part HA so as to be in parallel with the shaft core direction (width direction) of the second heating roller part  20 . For this reason, the second chamber  25  is allowed to pass through the cut-out parts K from the inside of the box part HA along the rail parts L through the sliding parts P, and is made slidable rearward of the box part HA. Additionally, at this time, the hole of the front face of the second chamber  25  passes through the drum  12 . 
     In the heating device H, by allowing the second chamber  25  to slide rearward of the box part HA, an advantage of easy maintenance can be obtained. 
     Moreover, the second chamber  25  has its inner wall face covered with a heat insulating material, not shown, having a heat insulating property in itself, such as glass wool or the like. For this reason, the second chamber  25  is allowed to exert a so-called heat shielding effect that suppresses the heat generated by the second heating roller part  20  and the second heating part  21  from transmitting to the outside of the second chamber  25 . 
     The second chamber  25  has a plurality of exhaust openings  15   a  formed on its side face in the same manner as in the aforementioned first chamber  15 . Moreover, each of the exhaust openings  15   a  is communicated with an exhaust-use air blower D 1  disposed on the outside of the second chamber  25  in the same manner as in the aforementioned first chamber  15 . Therefore, by operating the exhaust-use air blower D 1 , air inside the second chamber  25  can be exhausted from exhaust ducts, not shown, on the outside through the exhaust openings  15   a . Thus, in the second chamber  25 , even if the aqueous solvent is evaporated and floating, the aqueous solvent can be removed so that it becomes possible to prevent, for example, the floating aqueous solvent from re-adhering to the printed object X by dew condensation or from adhering to the inside of the drying device H to cause contamination. 
     Moreover, inside the second chamber  25 , a supply-use air blower D 2  for supplying air to the aforementioned second heating part  21  is disposed in parallel with the exhaust-use air blower D 1 . Additionally, a supply opening for supplying air to the second heating part  21  is also formed on the second chamber  25 ; however, illustration thereof is omitted because the position of the supply opening and the position of the second heating part  21  are overlapped with each other. 
     In the drying device H, the printed object X is directly guided from the second heating roller part  20  to the quick cooling roller  30 . That is, the printed object X guided to the second heating roller part  20  is designed to be guided to the quick cooling roller  30  immediately after having been ejected outside of the second chamber  25 . 
     At this time, the printed object X is abruptly cooled by the quick cooling roller from a state in which it has been heated by the second heating roller part  20  and the second heating part  24 . Thus, since the evaporation of the aqueous solvent in the printed object X is forcefully stopped, the evaporated aqueous solvent is prevented from being released out of the second chamber  25 . 
     The quick cooling roller  30  has a hollow column shape whose outer circumferential surface is designed to be cooled. Therefore, the printed object X is cooled by being made to contact with the outer circumferential surface of the quick cooling roller  30 . Additionally, the quick cooling roller  30  is preferably disposed so as to make the printing surface containing more of the aqueous solvent in contact therewith. 
     Additionally, the quick cooling roller  30  is supported by a frame attached to the box part HA of the drying device H. 
       FIG. 5  is a vertical cross-sectional view taken by cutting the quick cooling roller of the drying device in the width direction in accordance with the present embodiment. 
     As shown in  FIG. 5 , the quick cooling roller  30  is provided with a hollow column-shaped drum  31 , a cylinder part  31   b  built in a hollow part  31   a  of the drum  31 , a rotary joint  32  attached to one end of the drum  31  and an outgoing pipe  32   a  as well as a return pipe  32   b  attached to the rotary joint  32 . 
     In the quick cooling roller  30 , the hollow part  31   a  of the drum  31 , the rotary joint  32  and the inside of the outgoing pipe  32   a  and the return pipe  32   b  are communicated with one another. 
     In the quick cooling roller  30 , cooling water is allowed to flow into the drum  31  through the rotary joint  32 . 
     More specifically, in the quick cooling roller  30 , the cooling water is allowed to flow into an inside flow path  31   b   1  of the cylinder part  31   b  through the rotary joint  32  from the outgoing pipe  32   a , and when the cooling water collides with the other end of the drum  31 , it is guided to an outside flow path  31   b   2  of the cylinder part  31   b , and from the outside flow path  31   b   2 , it is allowed to flow out to the return pipe  32   b  through the rotary joint  32 . Thus, the quick cooling roller  30  can be sufficiently cooled. 
     In the drying device H, the printed object X is guided to the cooling roller  40  on the downstream side from the quick cooling roller  30  through a plurality of guide rollers. 
     A pair of the cooling rollers  40  are installed in the vertical direction. Each of the cooling rollers  40  has a hollow column shape, and its outer circumferential surface is designed to be cooled. For this reason, the printed object X is further cooled when made to contact with the outer circumferential surface of the cooling roller  40 . 
     Additionally, the cooling roller  40  is supported by a frame attached to the box part HA of the drying device H. 
       FIG. 6  is a vertical cross-sectional view taken by cutting the cooling roller of the drying device in the width direction in accordance with the present embodiment. 
     As shown in  FIG. 6 , each cooling roller  40  is provided with a hollow column-shaped drum  41 , a column part  41   b  built in a hollow part  41   a  of the drum  41 , a rotary joint  42  attached to each of two ends of the drum  41  and an outgoing pipe  42   a  attached to the rotary joint  42  on one end side as well as a return pipe  42   b  attached to the rotary joint  42  on the other end side. 
     In the cooling roller  40 , the hollow part  41   a  of the drum  41 , the rotary joints  42  on the two ends and the inside of the outgoing pipe  42   a  and the return pipe  42   b  are communicated with one another. 
     In the cooling roller  40 , cooling water is allowed to flow into the drum  41  through the rotary joints  42 . 
     More specifically, in the cooling roller  40 , the cooling water is guided to an outside flow path  41   b   2  of the column part  41   b  of the hollow part  41   a  through the rotary joint  42  on one end side from the return pipe  42   a , and is allowed to flow from the outside flow path  41   b   2  into a return pipe  42   b  through the rotary joint  42  on the other end side. Thus, the cooling roller  40  can be sufficiently cooled. 
     In the drying device H in the present embodiment, as described earlier, a wet printed object X immediately after the printing process is heated step by step by using the first heating roller part  10  and the first heating part  11 , as well as the second heating roller part  20  and the second heating part  21 , which have different setting temperatures; therefore, the printed object X can be positively dried and it also becomes possible to sufficiently suppress curling of the printed object X itself or wrinkles and cockling from occurring in the printed object X. 
     Moreover, the printed object X is sufficiently cooled by the quick cooling roller  30  and the cooling roller  40 ; therefore, in the case when the printed object X is collected by winding-up or the like, it becomes possible to suppress the dimensional changes of the printed object X at the time of winding-up as much as possible. 
     Furthermore, by returning the temperature of the printed object X to the state prior to the drying process, another printing process can be carried out on the rear surface of the printed object. 
     Next, explanation is given to an ink-jet printing device in accordance with the present invention. 
       FIG. 7  is a perspective side view showing an embodiment of the ink-jet printing device in accordance with the present invention. 
     As shown in  FIG. 7 , an ink-jet printing device I in accordance with the present embodiment is provided with a paper feeding part  61  for supplying a printing object X 1 , a printing part  62  for printing the printing object X 1  while transporting it and a drying device H for drying a long-sized printed object X that has been printed by the printing part  62  while transporting it and a collecting part  63  for collecting the dried printed object X. 
     In the ink-jet printing device I, the printing part  62  is constituted by a plurality of ink-jet printing heads. Additionally, as the system of the ink-jet printing heads, a line head system or a serial head system may be used. 
     Moreover, into each of the ink-jet printing heads, the aforementioned ink is filled for each of the colors of YMCK, or the like. 
     In the ink-jet printing device I, the printed object X is transported at a desired speed by rotating a pull roller  70  by a servo motor, not shown. 
     Moreover, the tension of the printed object X is detected by a tension roller  71  to which a tension sensor, not shown, using a load cell or the like is attached so that the rotation amount of the pull roller  70  can be adjusted by the servo motor so as to achieve a target tension. 
     Furthermore, the transporting path of the printed object X below the printing part  62  has an arch shape. Thus, it becomes possible to suppress flapping of the printed object X. 
     In the ink-jet printing device I, since the above-mentioned drying device H is installed, the printed object X that has been subjected to printing processes by the plural ink-jet printing heads can be dried immediately after the printing processes, the printed object X itself is suppressed from being curled, and it becomes possible to sufficiently suppress wrinkles and cockling from occurring in the printed object X. 
     Although embodiments of the present invention have been explained above, the present invention is not intended to be limited by the above-mentioned embodiments. 
     The drying device H of the present embodiment is provided with the auxiliary heating part  50 ; however, the auxiliary heating part  50  is not necessarily an indispensable component. 
     In the drying device H in accordance with the present embodiment, the first heating roller part  10  is provided with the hollow column-shaped drum  12 , the band heater  13  for heating the drum  12  and the shaft core  16  to which the two sides of the drum  12  are attached and fixed; however, the first heating roller part  10  is not limited by this structure, as long as the outer circumferential surface of the first heating roller part  10  can be heated. Additionally, the same is true for the second heating roller part  20 . 
     In the drying device H in accordance with the present embodiment, the drum  12  of the first heating roller part  10  has its outer circumferential surface subjected to irregularity machining; however, this process is not necessarily required. 
     Moreover, instead of the irregularity machining, thin grooves may be formed on the surface of the drum  12 . 
     Additionally, the same is true for the drum of the second heating roller part  20 . 
     In the drying device H in accordance with the present embodiment, as the heating part  11 , the first hot air blowing devices  14  that are arranged side by side are exemplified; however, the present invention is not intended to be limited by this structure, as long as at least one surface of the printed object X can be heated and dried. Additionally, the same is true for the auxiliary heating part  50  and the second heating part  21 . 
     In the drying device H in accordance with the present embodiment, the first chamber  15  for housing the first heating roller part  10  and the first heating part  11  is not necessarily an indispensable component. 
     That is because although the chamber is used for enclosing floating aqueous solvent so as to be removed, the setting temperatures of the first heating roller part  10  and the first heating part  11  are not temperatures that positively evaporate the aqueous solvent. 
     Moreover, for the same reason as described above, in the drying device H, no quick cooling roller to be proximately placed thereto is installed in the first heating roller part  10 . 
     Additionally, in order to positively prevent the aqueous solvent from floating, it is of course possible to install the first chamber  15  and also to install the quick cooling roller proximately located to the first heating roller part  10 . 
     In the drying device H in accordance with the present embodiment, the quick cooling roller  30  is provided with the hollow column-shaped drum  31 , the cylinder part  31   b  built in a hollow part  31   a  of the drum  31 , the rotary joint  32  attached to one end of the drum  31  and the outgoing pipe  32   a  as well as the return pipe  32   b  attached to the rotary joint  32 ; however, the present invention is not intended to be limited by this structure as long as the printed object X can be cooled. 
     In the drying device H in accordance with the present embodiment, the cooling roller  40  is provided with the hollow column-shaped drum  41 , the column part  41   b  built in a hollow part  41   a  of the drum  41 , the rotary joint  42  attached to each end of the drum  41  and the outgoing pipe  42   a  attached to the rotary joint  42  on one end side as well as the return pipe  42   b  attached to the rotary joint  42  on the other end side; however, the present invention is not intended to be limited by this structure as long as the printed object X can be cooled. 
     INDUSTRIAL APPLICABILITY 
     The drying device of the present invention can be utilized as a device in which while transporting a long-sized printed object that is formed by applying an ink onto a printing object in a printing part of a printing device, the printed object is dried. In accordance with the drying device, the printed object can be dried, and it becomes possible to sufficiently suppress curling of the printed object itself or wrinkles and cockling from occurring in the printed object. 
     The ink-jet printing device of the present invention can be utilized as a device in which by applying an ink to a printing object, characters and patterns can be printed thereon. In accordance with the ink-jet printing device, since the printing device is provided with the above-mentioned drying device, the printed object can be dried, and it becomes possible to sufficiently suppress curling of the printed object itself or wrinkles and cockling from occurring in the printed object. 
     REFERENCE SIGNS LIST 
     
         
         
           
               10  . . . first heating roller part (heating roller part), 
               11  . . . first heating part (heating part), 
               12 ,  31 ,  41  . . . drum, 
               13  . . . band heater, 
               13   a  . . . power source terminal, 
               13   b  . . . thermocouple, 
               13   c  . . . thermostat, 
               14  . . . first hot air blowing device (hot air blowing device), 
               14   a  . . . blowing unit, 
               14   a   1  . . . sheath heater, 
               14   a   2  . . . nozzle pipe, 
               14   a   3  . . . heater cover, 
               14   a   4  . . . bottom plate, 
               15  . . . first chamber (chamber), 
               15   a  . . . exhaust opening, 
               16  . . . shaft core, 
               16   a  . . . power source-use rotary connector, 
               16   b  . . . signal-use rotary connector, 
               20  . . . second heating roller part (heating roller part), 
               21  . . . second heating part (heating part), 
               24  . . . second hot air blowing device (hot air blowing device), 
               25  . . . second chamber (chamber), 
               30  . . . quick cooling roller, 
               31 ,  41  . . . drum, 
               31   a ,  41   a  . . . hollow part, 
               31   b  . . . cylinder part, 
               31   b   1  . . . inside flow path, 
               31   b   2 ,  41   b   2  . . . outside flow path, 
               32 ,  42  . . . rotary joint, 
               32   a ,  42   a  . . . outgoing pipe, 
               32   b ,  42   b  . . . return pipe, 
               40  . . . cooling roller, 
               41   b  . . . column part, 
               50  . . . auxiliary heating part, 
               51  . . . auxiliary hot air blowing device, 
               61  . . . paper feeding part, 
               62  . . . printing part, 
               63  . . . collecting part, 
               70  . . . pull roller, 
               71  . . . tension roller, 
             B 1 , B 2  . . . bracket, 
             D 1  . . . exhaust-use air blower, 
             D 2  . . . supply-use air blower, 
             F 1  . . . frame, 
             H . . . drying device, 
             HA . . . box part, 
             H 1  . . . shortest distance, 
             H 2  . . . width, 
             I . . . ink-jet printing device, 
             K . . . cut-out part, 
             L . . . rail part, 
             N . . . nozzle part, 
             P . . . slide part, 
             R . . . rib part, 
             S . . . slit, 
             T . . . gap, 
             X . . . printed object, 
             X 1  . . . printing object