Printing apparatus

Abstract

The present invention provides a printing apparatus that prevents ink re-transfer, suppresses the diffusion of ink odor and paper dust, and enables the production of high-quality printed materials. [Solution] The system includes a line head 33 for printing on a sheet P, and a first circulating conveyor roller 35 located downstream of the line head 33 in the conveying direction of the sheet P. The first circulating conveyor roller 35 is a pair of hollow rollers, and the first roller 35a of the first circulating conveyor roller 35 has a blow hole 35c on its surface, which blows air from the inside to the outside of the hollow roller, and the second roller 35b, which is opposite the first roller 35a, has a suction hole 35d on its surface, which sucks the air blown out from the first roller 35a into the inside of the hollow roller.

Description

Technical Field

[0001] The present invention relates to a printing apparatus having a drying function for a printed medium that has undergone printing processing.

Background Art

[0002] Conventionally, an inkjet printing apparatus has been proposed that ejects ink onto a printing medium from an inkjet head to perform printing processing.

[0003] Moreover, not only inkjet printing apparatuses but also printing apparatuses of other printing methods, including those, the speed of printing processing has been increasing. Particularly in the case of the inkjet printing method, since ink is ejected onto a printing medium to perform printing processing, the drying time of the ink has a great influence on the increase in the speed of printing processing.

[0004] Therefore, for example, in Patent Document 1, an inkjet printing apparatus provided with a drying apparatus for drying a printed medium that has undergone printing processing has been proposed. In Patent Document 1, drying processing is performed by blowing air onto the surface of a recording medium conveyed by a drying conveyance unit.

[0005] Moreover, in Patent Document 2, an inkjet printing apparatus has been proposed that has a semi-cylindrical paper drying path for inverting the paper immediately after printing processing that has been conveyed upward, and a heat source is provided on the arc center side of the semi-cylindrical paper drying path.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0007] However, in Patent Document 1, the printed medium is handed over to the drying transport unit, but there is a possibility that the printed medium may be handed over to the drying transport unit without sufficient time for the ink to penetrate and dry into the medium. As a result, the ink is transferred to the transport drying unit, and then the ink is re-transferred to the next printed medium that is transported.

[0008] Similarly, in Patent Document 2, ink is transferred to the paper drying path, and then the ink is re-transferred to the printing medium that is transported next.

[0009] Furthermore, inks can emit a distinctive odor when drying, and this odor is particularly strong with quick-drying inks. In addition, inexpensive papers such as newsprint generate paper dust from the surface and cut edges, which diffuses, adheres to, and accumulates inside the printing device. Patent documents 1 and 2 do not consider these issues of odor and paper dust generation during the printing process.

[0010] In addition, Patent Document 3 proposes a hollow cooling roller for cooling the paper on which the toner image has been fixed, but it does not propose any drying function or measures to address the odor and paper dust mentioned above.

[0011] In view of the above circumstances, the present invention aims to provide a printing apparatus that prevents ink retransfer, suppresses the diffusion of ink odor and paper dust, and can produce high-quality printed materials. [Means for solving the problem]

[0012] The printing apparatus of the present invention comprises a printing processing unit that performs a printing process on a printing medium, and a pair of transport rollers provided downstream of the printing processing unit in the transport direction of the printing medium, wherein the pair of transport rollers are a pair of hollow rollers, and the first roller of the pair of transport rollers has a blow hole on its surface that blows air out from the inside to the outside of the hollow roller through the blow hole, and the second roller opposite the first roller has a suction hole on its surface that sucks the air blown out from the first roller into the inside of the hollow roller through the suction hole. [Effects of the Invention]

[0013] According to the printing apparatus of the present invention, a pair of transport rollers are provided downstream of the printing processing unit in the transport direction of the printing medium. The first roller of the pair of transport rollers blows air from the inside to the outside of the hollow roller through a blow hole provided on its surface, and the second roller, which is opposite the first roller, sucks the air blown out from the first roller into the inside of the hollow roller through a suction hole provided on its surface. As a result, the printing medium can be sufficiently dried by the air blown out from the first roller, thereby preventing re-transfer of ink, and the suction of air by the second roller suppresses the diffusion of ink odor and paper dust, making it possible to obtain printed materials with good image quality. [Brief explanation of the drawing]

[0014] [Figure 1] This figure shows a schematic configuration of an inkjet printing apparatus using one embodiment of the present invention. [Figure 2] Enlarged view of the vicinity of the first circulating conveyor roller. [Figure 3] A diagram showing an example of the surface of the first roller. [Figure 4] Plan view of an example of a sheet metal component. [Figure 5] Figure 1 shows a block diagram illustrating the configuration of the control system for the inkjet printing apparatus. [Figure 6] Table showing an example of airflow control in response to the requirement of reducing operating noise. [Modes for carrying out the invention]

[0015] Hereinafter, an inkjet printing apparatus using an embodiment of the printing apparatus of the present invention will be described in detail with reference to the drawings. The inkjet printing apparatus of this embodiment is characterized by a drying mechanism for a conveyed sheet. First, the overall configuration will be described. FIG. 1 is a diagram showing a schematic configuration of the inkjet printing apparatus 1 of this embodiment. The up-down, front-back directions shown in FIG. 1 are the up-down, front-back directions of the inkjet printing apparatus 1 of this embodiment. The front side of the paper surface in FIG. 1 is the right direction, and the back side of the paper surface is the left direction. Also, the front direction shown in FIG. 1 is the conveyance direction of the sheet P, the rear side is the upstream side in the conveyance direction, and the front side is the downstream side in the conveyance direction.

[0016] The inkjet printing apparatus 1 of this embodiment includes a paper feeding unit 30, a registration sensor RS, a registration unit 31, four line heads 33, a conveyance unit 34, a circulation conveyance path CR, first to fifth circulation conveyance rollers 35 to 39, a paper discharge roller 40, a first reverse conveyance roller 41, a reverse roller 42, and a second reverse conveyance roller 44.

[0017] The paper feeding unit 30 includes a paper feed table 30a, a scraper 30b, a guiding plate 30c, and a pickup roller 30d.

[0018] The paper feed table 30a has a plurality of sheets P (for example, printing paper) stacked thereon. The scraper 30b rotates while contacting the upper surface of the sheet P stacked on the paper feed table 30a. The guiding plate 30c is composed of a high-friction member such as a rubber plate provided on the downstream side in the conveyance direction of the sheet P with respect to the scraper 30b. The pickup roller 30d is rotatably provided above the guiding plate 30c and conveys the sheet P by guiding it between the guiding plate 30c.

[0019] The scraper 30b and the pickup roller 30d are driven by a first paper feeding drive motor 50 (see FIG. 5).

[0020] The scraper 30b presses against the top sheet P stacked on the paper feed tray 30a with a predetermined pressure, and the frictional force causes the sheet P to flow downstream. Even if multiple sheets P are picked up by the scraper 30b, the separating plate 30c and the pickup roller 30d separate only one sheet at a time and transport it further downstream to the resist section 31. In this way, the paper feed section 30 picks up the sheets P stacked on the paper feed tray 30a one by one and transports them to the resist section 31.

[0021] The scraper 30b and pickup roller 30d rotate in the direction of conveying the sheet P by the first paper feed drive motor 50, but are assisted when the sheet P is conveyed by the resist unit 31. In the assist control, the sheet P is conveyed at a faster conveying speed than the resist unit 31 while the sheet P is being conveyed by the resist unit 31, thereby creating slack in the sheet P. Then, the conveying speed is reduced so that the slack is gradually eliminated.

[0022] The resist section 31 is located downstream of the pickup roller 30d in the direction of sheet P transport and has a pair of nip rollers that grip the sheet P. When the leading edge of the sheet P fed from the paper feeding section 30 comes into contact with the resist section 31, its skew is corrected, and then the above-described assist control is performed to create slack. The resist section 31 then gradually eliminates the slack and transports the sheet P toward the transport section 34 located downstream in the direction of transport. The resist section 31 is driven by a resist roller drive motor 51 (see Figure 5).

[0023] The resist sensor RS is positioned between the pickup roller 30d and the resist unit 31 to detect the sheet P being transported. The detection signal from the resist sensor RS is output to the control unit 70, which controls the start and stop of rotation of the resist unit 31 based on the detection signal from the resist sensor RS.

[0024] The conveying unit 34 comprises a conveying belt 34a and platen rollers 34b. The conveying belt 34a is formed from an annular endless belt and has numerous suction holes. The conveying belt 34a is stretched over four platen rollers 34b that extend in a direction perpendicular to the conveying direction. The sheet P conveyed by the resist unit 31 is conveyed to the annular conveying belt 34a. The sheet P is then attracted onto the conveying belt 34a by suction from a suction fan (not shown) installed on the underside of the conveying surface of the conveying belt 34a and conveyed at a predetermined conveying speed. As the sheet P is conveyed by the conveying belt 34a, ink is discharged from the line head 33 onto the sheet P, thereby performing a printing process on the sheet P. The platen rollers 34b are driven by a platen roller drive motor 52 (see Figure 5).

[0025] Each line head 33 consists of multiple inkjet heads arranged in a direction perpendicular to the transport direction of the sheet P. The four line heads 33 are arranged at predetermined intervals along the transport path of the sheet P, as shown in Figure 1. The four line heads 33 eject C (cyan), M (magenta), Y (yellow), and K (black) inks, respectively. In this embodiment, the four line heads 33 correspond to the printing processing unit of the present invention.

[0026] The sheets P, which have been printed by the four line heads 33, are transported along the circulating transport path CR by the first to fifth circulating transport rollers 35 to 39, which are positioned on the circulating transport path CR. In this embodiment, the first circulating transport roller 35, which is initially provided on the downstream side in the transport direction of the four line heads 33, corresponds to the pair of transport rollers of the present invention and has a drying function (mechanism) for the printed sheets P. The configuration of the first circulating transport roller 35 and its surroundings will be described in detail later.

[0027] The first circulating conveyor roller 35 is rotationally driven by the first upward conveyor motor 53 (see Figure 5), the second circulating conveyor roller 36 is rotationally driven by the second upward conveyor motor 54 (see Figure 5), the third circulating conveyor roller 37 is rotationally driven by the first horizontal conveyor motor 55 (see Figure 5), and the fourth to fifth circulating conveyor rollers 38, 39 and the first reversing conveyor roller 41 are rotationally driven by the second horizontal conveyor motor 56 (see Figure 5).

[0028] Furthermore, a switching mechanism 43 is provided at the end of the fifth circulating transport roller 39 to switch between guiding the sheet P toward the paper discharge roller 40 or toward the first reversing transport roller 41.

[0029] When performing single-sided printing, the single-sided printed sheet P is guided by the switching mechanism 43 towards the paper discharge roller 40 and discharged onto the paper discharge tray 45. The paper discharge roller 40 is rotationally driven by the paper discharge transport motor 57 (see Figure 5). On the other hand, when performing double-sided printing, the single-sided printed sheet P is guided by the switching mechanism 43 towards the first reversing transport roller 41.

[0030] The sheet P, guided to the first reversing conveyor roller 41 by the switching mechanism 43, is then conveyed by the first reversing conveyor roller 41 toward the reversing roller 42.

[0031] The reversing roller 42 transports the sheet P toward the reversing table 46 and then returns it from the reversing table 46, thereby transporting the sheet P toward the second reversing transport roller 44 with its front and back sides reversed. The reversing roller 42 is rotationally driven by the reversing transport motor 58 (see Figure 5).

[0032] The sheet P, now inverted, is transported back to the resist section 31 by the second inversion transport roller 44, and then transported back to the transport section 34 by the resist section 31 at a predetermined timing. The back side of the sheet P is then printed by the line head 33.

[0033] The sheet P, which has been printed on its reverse side, is transported by the first to fifth circulating transport rollers 35 to 39, and then transported to the paper output tray 45 via the paper output roller 40 through the switching mechanism 43.

[0034] Next, the configuration of the first circulating conveying roller 35, which has a drying function as described above, and its surrounding area will be explained in detail.

[0035] Figure 2 is an enlarged view of the vicinity of the first circulating conveyor roller 35. As shown in Figure 2, the first circulating conveyor roller 35 has a first roller 35a and a second roller 35b provided opposite the first roller 35a. The first roller 35a and the second roller 35b are cylindrical hollow rollers.

[0036] A shaft S1 and ribs R1 are provided inside the hollow of the first roller 35a. The shaft S1 is rotationally driven by the first lifting conveyor motor 53 (see Figure 5), which causes the first roller 35a to rotate. The ribs R1 are plate-shaped members provided between the shaft S1 and the peripheral wall of the first roller 35a, and extend along the length of the first roller 35a. Four ribs R1 are provided in a cross shape with the shaft S1 as the center. Note that the shape of the ribs R1 is not limited to the cross shape shown in Figure 2, but may also be helical.

[0037] Multiple blow holes 35c are formed on the surface of the first roller 35a. Figure 3 shows the surface of the first roller 35a, and the left-right direction shown in Figure 3 is the longitudinal direction of the first roller 35a. As shown in Figure 3, multiple rows of multiple blow holes 35c are formed on the surface of the first roller 35a at predetermined intervals, oblique to the longitudinal direction of the first roller 35a.

[0038] Furthermore, as shown in Figure 3, the air outlet 35c is formed in a teardrop shape. Specifically, the air outlet 35c is formed such that the opening is larger on the downstream side than on the upstream side in the conveying direction of the sheet P. This allows air to be blown out from the first roller 35a toward the downstream side in the conveying direction, and a wide area of ​​the surface of the sheet P can be exposed to the air. However, the shape of the air outlet 35c is not limited to this shape, and other shapes may be adopted.

[0039] The airflow generated in the airflow generating unit 80 (see Figure 5) flows into the hollow space of the first roller 35a, and this inflow causes air to be blown out from the inside to the outside of the first roller 35a through the outlet hole 35c. The arrow shown on the first roller 35a in Figure 2 indicates the direction of the blown air described above. The blown air from the first roller 35a is directed towards the sheet P, thereby promoting the drying of the sheet P.

[0040] A shaft S2 and ribs R2 are provided inside the hollow of the second roller 35b. The second roller 35b is a driven roller and rotates around the shaft S2 in conjunction with the rotation of the first roller 35a. Four ribs R2 are provided in a cross shape around the shaft S2, similar to ribs R1. The shape of the ribs R2 may also be helical.

[0041] Multiple suction holes 35d are formed on the surface of the second roller 35b. The hollow interior of the second roller 35b is under negative pressure due to air being sucked in by the suction unit 90 (see Figure 5), which draws the air blown out from the first roller 35a into the inside of the second roller 35b through the suction holes 35d. In Figure 2, the arrows shown on the second roller 35b indicate the direction of air suction as described above. By drawing in the air blown out with the second roller 35b, the generation of odors caused by the volatilization of solvents in the ink on the sheet P by the air blown out can be suppressed.

[0042] The suction holes 35d formed on the surface of the second roller 35b are also formed in a teardrop shape, similar to the blowing holes 35c formed on the surface of the first roller 35a. Specifically, the suction holes 35d are formed so that the opening is larger on the downstream side than on the upstream side in the conveying direction of the sheet P. This allows for more efficient collection of air. However, the shape of the suction holes 35d is not limited to this shape, and other shapes may be adopted.

[0043] Furthermore, the number and size of the blow holes 35c on the surface of the first roller 35a and the suction holes 35d on the surface of the second roller 35b are changed depending on the roller diameter, length, and material.

[0044] Furthermore, a cover member 35e is provided on the outside of the first roller 35a, and a cover member 35f is provided on the outside of the second roller 35b. The cover members 35e and 35f are provided to prevent the air blown out from the first roller 35a from spreading to the surroundings.

[0045] The cover member 35e has a cylindrical portion formed along the outer circumference of the first roller 35a and a box-shaped portion extending downstream from the cylindrical portion in the conveying direction. By forming the cylindrical portion in this way, the air blown out from the first roller 35a can be efficiently collected, and by forming the box-shaped portion, the air blown out from the first roller 35a can be efficiently directed over a wide area of ​​the conveyed sheet P.

[0046] The cover member 35f has a cylindrical portion formed along the outer circumference of the second roller 35b and a box-shaped portion extending downstream from the cylindrical portion in the conveying direction. By forming the cylindrical portion in this way, air blown out from the first roller 35a can be efficiently collected and sucked in by the second roller 35b, and by forming the box-shaped portion, air directed from the box-shaped portion of the cover member 35e toward the sheet P can be efficiently collected.

[0047] Furthermore, two sheet metal members 60 for conveying the sheet P are provided between the first roller 35a and the second roller 35b. The two sheet metal members 60 are provided with a predetermined gap between them, and are arranged so that the sheet P passes between the two sheet metal members 60.

[0048] Figure 4 is a plan view of an example of a sheet metal member 60. As shown in Figure 4, the sheet metal member 60 has a window portion 61 for exposing the first roller 35a or the second roller 35b onto the conveying path of the sheet P. In addition, a number of ventilation holes 62 are formed in the area facing the box-shaped portions of the cover members 35e and 35f. Air blown out from the blowing hole 35c of the first roller 35a and collected by the box-shaped portion of the cover member 35e passes through the ventilation holes 62 and is directed onto the sheet P, and then collected by the box-shaped portion of the cover member 35f.

[0049] Furthermore, as shown in Figure 3, two shutter members 63 are provided on the sheet metal member 60 on the side of the first roller 35a. The two shutter members 63 are provided on both sides of the area in the sheet metal member 60 where the ventilation holes 62 are formed. The shutter members 63 are opened and closed by moving the two shutter members 63 toward and away from each other, thereby adjusting the number of ventilation holes 62 that are opened and the amount of air blown onto the sheet P.

[0050] Furthermore, the sheet metal member 60 on the second roller 35b side is not provided with the shutter member 63 described above.

[0051] Figure 5 is a block diagram showing the schematic configuration of the control system of the inkjet printing apparatus 1 in this embodiment.

[0052] The control unit 70 controls the entire inkjet printing apparatus 1 and includes a CPU (Central Processing Unit), semiconductor memory, and a hard disk. The control unit 70 controls the operation of each part of the inkjet printing apparatus 1 by executing a program pre-stored in a storage medium such as semiconductor memory or a hard disk, and by operating electrical circuits.

[0053] The airflow generating unit 80 and the suction unit 90 shown in Figure 5 include, for example, a fan, and generate or draw in airflow by rotating the fan. The airflow generating unit 80 may also be used to generate cooling air for cooling the line head 33. Specifically, the airflow generated in the airflow generating unit 80 may be used to cool the line head 33, and the cooling air used for that cooling may be supplied into the hollow of the first roller 35a.

[0054] As a cooling mechanism for the line head 33, for example, an airflow generated by a fan or the like is circulated as cooling air inside a head holder (not shown) in which the line head 33 is housed, and the line head 33 is cooled by this cooling air. Then, the cooling air that has passed between the line heads 33 inside the head holder is drawn in by a suction fan or the like, and the drawn-in cooling air is flowed into the hollow of the first roller 35a. The specific configuration of the cooling mechanism for the line head 33 can be, for example, the configuration described in Japanese Patent Application Publication No. 2016-155316, but the configuration is not particularly limited.

[0055] Furthermore, the amount of air blown onto the sheet P may be controlled based on the print density of the print image printed on the sheet P. Specifically, the control unit 70 may calculate the print density of the print image using the image data of the print image included in the input print job, and control the airflow so that the higher the print density, the greater the airflow. Methods for controlling the amount of air blown onto the sheet P include increasing the amount of air blown out from the first roller 35a or increasing the amount of air drawn in by the second roller 35b. The amount of air blown onto the sheet P can be controlled by controlling the airflow of at least one of the blown air and the drawn air.

[0056] Furthermore, the airflow rate blown onto the sheet P may be changed according to the requirement for reducing operating noise. Specifically, increasing the airflow rate blown onto the sheet P improves the drying efficiency of the sheet P, but on the other hand, the operating noise increases proportionally to the airflow rate. Therefore, as mentioned above, the airflow rate may be changed according to the requirement for reducing operating noise.

[0057] Figure 6 is a table showing an example of airflow control in response to the requirement of reducing operating noise. In the table shown in Figure 6, four modes are pre-set as operating modes corresponding to the requirement of reducing operating noise: a fresh paper mode, a high print density mode, a medium print density mode, and a low print density mode. The control unit 70 controls the airflow and operating noise blown onto the sheet P by controlling the air blown out from the first roller 35a and the air drawn in by the second roller 35b according to these four pre-set modes.

[0058] The newsprint mode is a mode primarily used for printing on newsprint. Newsprint absorbs ink easily, resulting in relatively good drying efficiency, but it also tends to generate paper dust. Therefore, when in newsprint mode, the control unit 70 stops the operation of the airflow generation unit 80 to stop the airflow from the first roller 35a, but operates the suction unit 90 to draw air from the second roller 35b. This reduces operating noise by stopping the airflow from the first roller 35a, and also allows for efficient collection of paper dust generated from the newsprint.

[0059] The high print density mode is used when the print density of the printed image is high. In high print density mode, because the print density is high, it is preferable to prioritize ink drying over reducing operating noise. Therefore, when in high print density mode, the control unit 70 operates both the airflow generating unit 80 and the suction unit 90 to blow air from the first roller 35a and suck air from the second roller 35b. This allows for priority drying of the ink on the sheet P.

[0060] The medium print density mode is used when the print density of the printed image is lower than in the high print density mode but higher than in the low print density mode. In the medium print density mode, since the print density is moderate, the drying capacity required is not as high as in the high print density mode. Therefore, when the machine is in the medium print density mode, the control unit 70 operates the airflow generator 80 to blow air from the first roller 35a, but stops the suction unit 90 and does not draw air from the second roller 35b. This allows for a certain level of drying capacity to be obtained while also reducing operating noise.

[0061] The low print density mode is used when the print density of the printed image is lower than that of the medium print density mode. In low print density mode, drying capacity is not required because the print density is low, and it is preferable to prioritize reducing operating noise. Therefore, when in low print density mode, the control unit 70 stops both the airflow generation unit 80 and the suction unit 90. This further reduces operating noise.

[0062] Furthermore, the four modes—new paper mode, high print density mode, medium print density mode, and low print density mode—may be set manually by the user, or the control unit 70 may acquire information on the print density of the printed image and the paper type of sheet P and automatically switch modes based on this information.

[0063] According to the inkjet printing apparatus 1 of the above embodiment, the first roller 35a blows air through the blowing hole 35c, and the second roller 35b sucks in the air blown out from the first roller 35a through the suction hole 35d. As a result, the sheet P can be sufficiently dried by the air blown out from the first roller 35a, thereby preventing re-transfer of ink. Furthermore, the suction of air by the second roller 35b suppresses the diffusion of ink odor and paper dust, making it possible to obtain printed materials with good image quality.

[0064] Furthermore, in the inkjet printing apparatus 1 of the above embodiment, the first circulating transport roller 35, which is initially provided on the downstream side of the line head 33 in the transport direction, is configured to blow and suck air. This allows the ink on the sheet P to dry before it reaches the other rollers, preventing ink from adhering to the other rollers.

[0065] Furthermore, in the inkjet printing apparatus 1 of the above embodiment, the blowing holes 35c and suction holes 35d are shaped such that the openings are larger on the downstream side than on the upstream side in the conveying direction of the sheet P. This allows air to be directed over a wide area of ​​the sheet P and to be collected more efficiently.

[0066] Furthermore, in the inkjet printing apparatus 1 of the above embodiment, cover members 35e and 35f are provided for the first circulating transport roller 35, which prevents the air blown out from the first roller 35a from diffusing into the surroundings and allows for efficient collection of the air blown out from the first roller 35a.

[0067] Furthermore, in the inkjet printing apparatus 1 of the above embodiment, if the amount of air blown onto the sheet P is controlled based on the print density of the print image printed on the sheet P, an appropriate amount of air corresponding to the amount of ink on the sheet P can be blown onto the sheet P, allowing the sheet P to dry sufficiently, and reducing operating noise without unnecessarily increasing the airflow.

[0068] Furthermore, in the inkjet printing apparatus 1 of the above embodiment, if the amount of air blown onto the sheet P is controlled in response to a preset request for noise reduction, the sheet P can be sufficiently dried, and noise can be reduced.

[0069] Furthermore, in the inkjet printing apparatus 1 of the above embodiment, if cooling air for cooling the line head 33 is introduced into the first roller 35a and this cooling air is blown out from the outlet hole 35c, there is no need to newly provide a mechanism such as an airflow generating unit 80, so the apparatus can be made smaller and less expensive.

[0070] It should be noted that the present invention is not limited to the embodiments described above, and the components can be modified and implemented in practice without departing from the spirit of the invention. Furthermore, various inventions can be formed by appropriately combining the multiple components disclosed in the embodiments described above. For example, all the components shown in the embodiments may be combined as appropriate. It goes without saying that various modifications and applications are possible without departing from the spirit of the invention.

[0071] The following further notes are disclosed regarding the present invention.

[0072] (Note 1) The printing apparatus of the present invention comprises a printing processing unit that performs a printing process on a printing medium, and a pair of transport rollers provided downstream of the printing processing unit in the transport direction of the printing medium, wherein the pair of transport rollers are a pair of hollow rollers, and the first roller of the pair of transport rollers has a blow hole on its surface that blows air out from the inside to the outside of the hollow roller through the blow hole, and the second roller opposite the first roller has a suction hole on its surface that sucks the air blown out from the first roller into the inside of the hollow roller through the suction hole.

[0073] (Note 2) In the printing apparatus described in Appendix 1, the pair of transport rollers may be the rollers initially provided on the downstream side in the transport direction of the printing processing unit.

[0074] (Note 3) In the printing apparatus described in Appendix 1 or 2, at least one of the blowing holes and the suction holes can be shaped such that the opening is larger on the downstream side than on the upstream side in the transport direction of the printing medium.

[0075] (Note 4) In the printing apparatus described in any of the appendices 1 to 3, a cover member may be provided on the outside of the pair of transport rollers to prevent the air blown out from the first roller from spreading to the surroundings.

[0076] (Note 5) In any of the printing apparatus described in Appendix 1 to 4, a control unit may be provided that controls the amount of air blown onto the printing medium based on the print density of the print image to be printed on the printing medium.

[0077] (Note 6) In any of the printing apparatus described in Appendix 1 to 5, a control unit may be provided that controls the amount of air blown onto the printing medium in response to a preset requirement for reducing operating noise. [Explanation of Symbols]

[0078] 1. Inkjet printing device 30 Paper feed section 30a Paper feed stand 30b Scraper 30cm filleting board 30d Pickup Roller 31 Resist section 33 Line Head 34 Conveying section 34a Conveyor belt 34b Platen Roller Circulating conveyor rollers 1-5 35-39 35a First Laura 35b The Second Laura 35c air outlet 35d suction hole 35e, 35f Cover members 40 Paper output roller 42 Reversible Roller 43 Switching mechanism 45 Paper output tray 46 Reversing platform 51 Registroller Drive Motor 52 Platen roller drive motor 53 First lifting transport motor 54. Second lifting transport motor 55. First horizontal transport motor 56. Second horizontal transport motor 57 Paper output motor 58 Reversing Transport Motor 60 Sheet metal components 61 Window section 62 ventilation holes 63 Shutter component 70 Control Unit 80 Airflow generating section 90 Suction part CR Circulation Transport Route P Sheet R1, R2 Ribs RS Resist Sensor S1, S2 shafts

Claims

1. A printing processing unit that performs printing on a printing medium, It has a pair of transport rollers provided downstream of the printing processing unit in the transport direction of the printing medium, The pair of conveying rollers are a pair of hollow rollers, The first roller in the pair of conveying rollers has a blow hole on its surface, and air is blown out from the inside to the outside of the hollow roller through the blow hole. A printing apparatus in which a second roller facing the first roller has suction holes on its surface, and which draws air blown out from the first roller into the inside of the hollow roller through the suction holes.

2. The printing apparatus according to claim 1, wherein the pair of transport rollers are the rollers initially provided on the downstream side in the transport direction of the printing processing unit.

3. The printing apparatus according to claim 1, wherein at least one of the blowing hole and the suction hole has a shape such that the opening is larger on the downstream side than on the upstream side in the transport direction of the printing medium.

4. The printing apparatus according to claim 1, further comprising a cover member provided on the outside of the pair of transport rollers to prevent the air blown out from the first roller from spreading to the surroundings.

5. The printing apparatus according to claim 1, further comprising a control unit that controls the amount of air blown onto the printing medium based on the print density of the print image to be printed on the printing medium.

6. The printing apparatus according to claim 1, further comprising a control unit that controls the amount of air blown onto the printing medium in response to a preset request for noise reduction.

Images