JP4693166B2 - Inkjet recording device - Google Patents

Description

  The present invention relates to an ink jet recording apparatus having a plurality of rows of ink jet heads in which a plurality of nozzles are arranged in a line in the sheet passing width direction, and more specifically, a cleaning unit that cleans the nozzle surface and a seal that seals the nozzle surface when not in use. The present invention relates to an ink jet recording apparatus having a stop.

  The ink jet recording apparatus performs printing by ejecting ink from a plurality of fine nozzles formed on the nozzle surface facing the sheet material of the ink jet head, and spraying the ink onto the sheet material conveyed by the conveyance belt. In this ink jet recording apparatus, since the above-described nozzles are exposed and exposed to the outside air, when the ink ejection operation is not performed for a long period of time, the ink near the nozzles is dried and solidified, and the nozzles are not visible. It may cause clogging.

  As a measure for preventing such a problem, generally, when the ink ejection operation is suspended for a long period of time, the nozzle is covered with a cap member (sealing member) to prevent the ink from drying and solidifying. I have to.

  By the way, in the ink jet recording apparatus, a plurality of nozzles are arranged in a line in the sheet passing width direction (left and right direction) orthogonal to the sheet material conveying direction to form an ink jet head, and the ink jet heads are arranged in a plurality of rows in the sheet material conveying direction. However, it is known that a plurality of inkjet heads print different colors for each line on a sheet material conveyed to a printing unit by a conveyance belt.

  For example, Patent Document 1 proposes a capping technique for an inkjet recording apparatus having an inkjet head that is long in the left-right direction. In this proposal, the cap member is disposed outside the printing unit, that is, outside the sheet passing width direction of the conveying belt for conveying the sheet material. For this reason, when capping, the inkjet head is moved from the printing unit in the paper passing width direction by a distance longer than the left and right lengths of the inkjet head to the retracted position above the cap member, and then the nozzle is covered with the cap member. Like to do.

  In such a configuration, the cap member requires a length in the sheet passing width direction that is approximately the same as the length of the ink jet head in the sheet passing direction, so that the area occupied by the ink jet recording apparatus (area in the top view) is large. As a result, the whole is enlarged.

  In order to prevent such an increase in size, Patent Document 2 discloses that a cap member is provided below the conveyor belt, and the cap member is moved along the outer peripheral surface of the conveyor belt as necessary and disposed in the printing unit. And what seals a nozzle with this cap member is proposed.

JP 2002-120386 A JP 2005-53119 A

  By the way, in the ink jet recording apparatus, as a technique for removing ink dried and solidified in the vicinity of the nozzle on the nozzle surface and ink adhering to the periphery of the nozzle when ink is ejected from the nozzle, the nozzle surface is rubbed with a cleaning member. A technique for wiping off ink adhering to the nozzle surface is known.

  However, when this technique is applied to the invention of Patent Document 2, a plurality of ink jet heads are arranged in a plurality of rows in the sheet material conveyance direction. For example, before the nozzle is covered with the cap member, the cleaning member When the ink on the nozzle surface is wiped off, the same cleaning member rubs the nozzle surfaces of a plurality of colors, so that there is a possibility that ink color mixing occurs on the nozzle surface. That is, according to Patent Document 2, although an increase in the occupied area due to the provision of the cap member can be suppressed, there is a problem that ink color mixing occurs when the cleaning member is used.

  An object of the present invention is to prevent an increase in the size of the entire apparatus due to an increase in occupied area caused by providing a cap member, and also prevent ink color mixing caused by wiping ink adhering to the nozzle surface with a cleaning member. It is an object of the present invention to provide an ink jet recording apparatus.

  The invention according to claim 1 relates to an ink jet recording apparatus that performs printing by spraying ink from a plurality of nozzles formed on a nozzle surface facing the printing unit to a sheet material conveyed to a printing unit by a conveying unit. Is. An ink jet recording apparatus according to the present invention includes an ink jet head having a plurality of the nozzles arranged in a paper passing width direction substantially orthogonal to a sheet material conveying direction, and a sealing belt that moves the printing portion endlessly in the paper width direction. Sealing means, and the inkjet head is arranged in a plurality of rows along the sheet material conveyance direction and ejects ink of a different color for each row from the plurality of nozzles. A cleaning unit that is rubbed against the nozzle surface as the sealing belt moves endlessly at different positions in the circumferential direction, and a sealing unit that seals the nozzle surface when placed in the printing unit, An opening that penetrates the sealing belt in the front and back direction and allows the ink to be ejected from the nozzles to the sheet material when disposed in the printing unit; When one of the sealing portion and the opening is disposed in the printing portion, the other is disposed so as to overlap with the other when viewed from a direction orthogonal to the nozzle surface. It is characterized by that.

  According to a second aspect of the present invention, in the ink jet recording apparatus according to the first aspect, the cleaning portion and the sealing portion are provided on an inner peripheral surface side of the sealing belt, and the ink jet head is sealed. It is arranged inside the belt.

  The invention according to claim 3 is the ink jet recording apparatus according to claim 1, wherein the cleaning portion and the sealing portion are provided on the outer peripheral surface side of the sealing belt and are conveyed by the conveying means. The material is conveyed so as to penetrate the inside of the sealing belt.

  The invention according to claim 4 is the ink jet recording apparatus according to any one of claims 1 to 3, further comprising elevating means for elevating and lowering the plurality of ink jet heads, and the elevating means is disposed in the printing unit. The nozzle surface of the ink jet is sealed by lowering and pressing the plurality of ink jet heads against the sealing portion.

  According to a fifth aspect of the present invention, in the inkjet recording apparatus according to any one of the first to fourth aspects, the cleaning belt and the sealing portion are integrally formed in the sealing belt. It is a feature.

  According to the first aspect of the present invention, the inkjet heads are arranged in a plurality of rows in the sheet material conveyance direction, and the inkjet heads in each row have a plurality of nozzles formed on the respective nozzle surfaces arranged in the sheet passing width direction. It is installed. Further, the sealing belt having the cleaning unit, the sealing unit, and the opening at different positions in the circumferential direction moves endlessly along the paper width direction of the printing unit. Here, the printing unit refers to a region where printing is actually performed on the sheet material with ink. The above-mentioned sealing belt can wipe the ink adhering to the nozzle surface by rubbing the nozzle surface by the cleaning unit, and can seal the nozzle surface by the sealing unit, Thus, the ink ejected from the nozzles can reach the sheet material. In addition, as the sealing belt moves endlessly in the sheet passing width direction, the cleaning unit also moves in the sheet passing width direction. Therefore, the cleaning unit includes a plurality of nozzles arranged in the sheet passing width direction for each inkjet head. The surface is rubbed along the arrangement direction of the plurality of nozzles. For this reason, the same part of the cleaning unit does not rub the nozzle surfaces in different rows. In other words, the nozzle surface having a plurality of nozzles in each row for ejecting ink of different colors is rubbed with a different portion of the cleaning unit to wipe off the ink. For this reason, it is possible to prevent color mixing of a plurality of colors caused by the cleaning unit rubbing the nozzle surface.

  In addition, when one of the sealing portion and the opening portion is disposed in the printing portion, the sealing belt is disposed so that the other overlaps with the other portion. An increase in the area occupied by the belt and thus the sealing means can be suppressed. In addition, an occupation area can be made small, so that the area of the overlapping part is large.

  Thus, according to the first aspect of the present invention, an increase in the occupied area due to the provision of the sealing means can be suppressed, and the ink surface caused by wiping the nozzle surface of each color by the cleaning unit can be suppressed. Color mixing can be prevented.

  According to the invention of claim 2, the cleaning portion and the sealing portion are provided on the inner peripheral surface side of the sealing belt, and the inkjet head can be disposed inside the sealing belt. The space inside the belt can be used effectively. In addition, according to this, since the sealing belt can be concentrated on the upper side of the printing unit, it is possible to easily perform the maintenance and the like of the conveying means disposed below the printing unit. it can.

  According to the invention of claim 3, the cleaning portion and the sealing portion are provided on the outer peripheral surface side of the sealing belt, and the sheet material can be conveyed so as to penetrate the inside of the sealing belt. The space inside the sealing belt can be used effectively. According to this, contrary to the above-described second aspect, since the sealing belt can be concentrated on the lower side of the printing portion, the inkjet head disposed above the printing portion can be arranged. Maintenance can be performed easily.

  According to the invention of claim 4, since the sealing surface is sealed by lowering and pressing the inkjet head by the lifting means with respect to the sealing portion arranged in the printing portion, the ink in the vicinity of the nozzle Drying and solidification of can be further reliably prevented.

  According to the invention of claim 5, since the cleaning portion and the sealing portion are integrally formed by the elastic member, the cleaning member and the sealing member are formed separately from the belt, and these are attached to the belt. Compared to the above, the manufacture of the sealing belt itself is easy. For example, the sealing belt can be integrally formed with a rubber member. In this case, at the time of molding, the cleaning unit and the sealing unit are molded so that they are positioned on the outer peripheral surface side, and then the cleaning unit and the sealing unit are directly used on the outer peripheral surface in accordance with the usage form of the sealing belt. On the contrary, the sealing belt can be reversed after molding so that the cleaning portion and the sealing portion are positioned on the inner peripheral surface side. That is, the sealing belt can be manufactured in the same manner both in the configuration in which the cleaning portion and the sealing portion are on the inner peripheral surface side, and on the contrary, in the configuration on the outer peripheral surface side.

  Hereinafter, the best embodiment of the present invention will be described in detail with reference to the drawings.

<Embodiment 1>
1, 2, 3, and 4 show an ink jet recording apparatus 10 according to the present invention. Among these, FIG. 1 is a view of the ink jet recording apparatus 10 as viewed from above. In the drawing, the right side is the upstream side in the transport direction (arrow Ks direction) of the sheet material S (copy paper, plastic film, envelope, etc. as recording material), and the left side is the downstream side. Here, the conveyance direction of the sheet material S and the opposite direction are appropriately referred to as “sheet conveyance direction” or simply “conveyance direction”. Further, the lower side and the upper side in FIG. 1 are the left side and the right side of the inkjet recording apparatus 10, respectively. According to this, the sheet passing width direction which is a direction orthogonal to the transport direction is the left-right direction. This sheet passing width direction (left-right direction) coincides with the direction of the leading edge S1 of the sheet material S in FIG. 2 and 3 are diagrams (views seen from the left side in FIG. 1) when the ink jet recording apparatus 10 is viewed from the downstream side to the upstream side in the transport direction. Among these, FIG. 2 shows a state in which a nozzle surface N of the inkjet head 12 to be described later is disposed at the retracted position, and the opening 45 of the sealing belt 13 is disposed at the printing portion P. FIG. 3 shows a state in which the sealing portion 44 of the sealing belt 13 is disposed at the printing portion P and the nozzle surface N of the inkjet head 12 is disposed at the sealing position. Finally, FIG. 4 shows that the openings 45a, 45b, 45c, and 45d of the sealing belt 13 are arranged in the printing portion P, and the nozzle surfaces N of the inkjet heads 12a, 12b, 12c, and 12d are arranged in the retracted positions. The figure which looked at the inkjet recording device 10 of the state of having been performed from the left side (figure seen from the lower side in FIG. 1) is shown. Here, the printing portion P refers to a region where printing is actually performed on the sheet material S with ink, and specifically, from the lower side of the upstream inkjet head 12a to the downstream inkjet head 12d. The area to be reached is shown.

  As shown in FIGS. 1 to 4, the inkjet recording apparatus 10 includes a transport unit 11 that transports a sheet material S, and a plurality of inkjet heads that perform printing on the surface of the sheet material S by ejecting ink from nozzles (not shown). 12a, 12b, 12c, and 12d, and a sealing belt 13 that cleans and seals the nozzle surface N on which the nozzles of the inkjet heads 12a to 12d are formed. In the following description, a case where there are four inkjet heads 12a, 12b, 12c, and 12d arranged in four rows from the upstream side to the downstream side will be described as an example. If there is no ink jet, it is simply referred to as “inkjet head 12”. The same applies to cleaning parts 43a, 43b, 43c, 43d, sealing parts 44a, 44b, 44c, 44d, and openings 45a, 45b, 45c, 45d described later. ”,“ Sealing portion 44 ”, and“ opening portion 45 ”.

  Hereinafter, the conveying unit 11, the inkjet head 12, and the sealing belt 13 will be described in this order.

  As shown in FIG. 4, the conveying unit 11 is hung on the driving roller 21 disposed on the downstream side in the sheet conveying direction, the driven roller 22 disposed on the upstream side, and the driving roller 21 and the driven roller 22. It is disposed above the conveyed conveyor belt 23 and the driving roller 21, and is disposed above the downstream conveying roller 24 that sandwiches the conveying belt 23 between the driving roller 21 and the driven roller 22. An upstream conveying roller 25 sandwiching the conveying belt 23 between the driven roller 22 and the driven roller 22 is provided.

  The conveyance belt 23 is formed in an endless shape (endless), and a width W23 (see FIG. 1) in the sheet passing width direction (left and right direction) is set wider than the maximum sheet passing width Wp of the sheet material S. Here, the maximum sheet passing width Wp means the sheet passing width of the sheet member S having the maximum sheet passing width among the sheet members S to be used for printing. The drive roller 21 is rotationally driven in the direction of arrow R21 by a transport motor (stepping motor) 27, whereby the transport belt 23 rotates (endlessly moves) in the direction of arrow R23. The rotation of the transport motor 27 is controlled by a CPU (control means) 28. The CPU 28 also controls the rotation of an elevating motor 36 of the elevating means 34 described later and a sealing motor 46 for rotating the sealing belt 13.

  Of the entire circumference of the conveyor belt 23, a portion located downstream of the driven roller 22 and upstream of the driving roller 21 along the rotation direction is defined as a forward side F, and downstream of the driving roller 21 and driven roller. Assuming that the portion located upstream of 22 is the return side R, the transport belt 23 is configured so that the forward side F is stretched with an appropriate tension at least in the rotating state. The surface side (the upper surface side in FIG. 4) on the forward side F described above is the sheet material carrying surface 23a.

  A flat guide plate 26 is disposed immediately below the forward side F of the conveyor belt 23. The guide plate 26 is formed to be approximately the same size as the forward side F of the conveyor belt 23, and is arranged substantially in parallel with the back surface of the forward side F in a stretched state with a small gap therebetween. Yes. The guide plate 26 prevents the forward side F from fluttering downward, and serves as a reaction member when sealing the nozzle surface N by the sealing portion 44, as will be described later.

  As shown in FIG. 1, the conveying means 11 having the above-described configuration carries the sheet material S conveyed in the direction of the arrow Ks from the upstream side on the sheet material carrying surface 23 a on the forward side F of the conveyance belt 23. The sheet material S is passed through the printing portion P and further conveyed downstream.

  Prior to carrying the sheet material S on the sheet material carrying surface 23a by the conveying means 11, for example, a voltage is applied to the upstream conveying roller 25 to apply an electric charge to the sheet material S. The sheet material S may be electrostatically attached to the sheet material carrying surface 23 a of the transport belt 23.

  As shown in FIGS. 2 and 3, each inkjet head 12 is formed long in the left-right direction and constitutes a so-called line head. In the present embodiment, four inkjet heads 12a, 12b, 12c, and 12d that are long in the sheet passing width direction (left and right direction) are arranged at equal intervals from the upstream side to the downstream side, as shown in FIG.

  Each inkjet head 12 has a flat nozzle surface N that faces the forward side F of the above-described transport belt 23, and nozzles (not shown) for ejecting (discharging) ink on the nozzle surface N. ) Are arranged in a line along a sheet passing width direction (left and right direction) substantially orthogonal to the sheet conveying direction. Here, “substantially orthogonal” means that it is desirable to be orthogonal, but a slight deviation due to a manufacturing error or an assembly error is allowed. For example, when the resolution of the inkjet recording apparatus 10 is 600 dpi (dot / inch: number of dots per inch), the nozzle has a diameter of about 20 μm and a pitch between adjacent nozzles of about 40 μm. The nozzles arranged in a line may be arranged in a line in a line in the sheet passing width direction, or may be arranged in a staggered pattern in the sheet passing width direction. When the distance between the nozzle located at the left end of each inkjet head 12 and the nozzle located at the right end is defined as an effective print range, this effective print range is set to be approximately the same as the above-described maximum sheet passing width Wp. The nozzle surface N described above is subjected to water repellent finishing.

  The four inkjet heads 12a, 12b, 12c, and 12d are arranged at predetermined intervals in order from the upstream side, and are configured to eject inks of different colors. For example, yellow, magenta, cyan, and black inks are ejected in order from the upstream side. All of these four inkjet heads 12 are arranged above the above-described guide plate 26, that is, in an area occupied by the above-described guide plate 26 in a top view. In the present embodiment, the four-color inkjet heads 12a to 12d can perform printing on the sheet material S in units of lines with different colors, and can perform four-color full-color printing as a whole.

  As shown in FIGS. 1 to 4, the four inkjet heads 12 are held by a plate-like head fixing member 31 disposed above them. The head fixing member 31 has a head support member 32 projecting from the left end side and the right end side toward the upstream side and the downstream side, respectively. The four inkjet heads 12 are integrally formed with the head fixing member 31 and the head support member 32, and constitute a head unit 33 as a whole. The head unit 33 is supported by an ink jet recording apparatus main body (not shown) via a head support member 32 so as to be lifted and lowered by a lifting means 34 shown in FIG. The lifting / lowering means 34 includes four cams 35 (only one cam 35 is shown in FIG. 4) and cams 35 each having a cam surface that comes into contact with each of the four head support members 32 from below. And a lift motor (stepping motor) 36 for controlling the rotation angle. The head unit 33 moves up and down in accordance with the rotation angle of the cam 35, and accordingly, the nozzle surface N (or nozzle) is in a retracted position allowing the rotation of the sealing belt 13 shown in FIG. They are arranged at a printing position (not shown) for printing on the material S and a sealing position for sealing the nozzle surface N shown in FIG. The retreat position, the printing position, and the sealing position will be described in detail after the sealing belt 13 is described.

  The inkjet heads 12a, 12b, 12c, and 12d configured as described above are carried in this order with respect to the sheet material S that is carried on the sheet material carrying surface 23a of the carrying belt 23 of the carrying unit 11 and conveyed to the printing unit P. Printing is performed on the surface of the sheet material S by ejecting ink of each color of yellow, magenta, cyan, and black in line units.

  As shown in FIGS. 1 to 3, the sealing belt 13 is stretched between a driving roller 41 and a driven roller 42. These sealing belt 13, drive roller 41, and driven roller 42 constitute a sealing means. The drive roller 41 is disposed above the right end side of the transport belt 23. The drive roller 41 has a shaft 41a directed in the sheet conveying direction, and a plurality (five in this embodiment) of roller members 41b attached to the shaft 41a. As shown in FIG. 4, among the roller members 41b, those on the most upstream side and the most downstream side are disposed at positions corresponding to the upstream end and the downstream end of the above-described guide plate 26, respectively, and the remaining 3 The individual roller members 41b are disposed at positions that equally divide between the above-mentioned most upstream roller member 41b and the most downstream roller member 41b. As will be described later, the positions corresponding to the two adjacent roller members 41b among these five roller members 41b are each set of a cleaning portion 43, a sealing portion 44, and an opening portion of the sealing belt 13. 45 comes to pass.

  The driven roller 42 is disposed above the left end side of the conveyor belt 23 so as to correspond to the drive roller 41 described above. The driven roller 42 has a shaft 42a directed in the sheet conveying direction, and a plurality (five in this embodiment) of roller members 42b attached to the shaft 42a. These roller members 42b are disposed at positions corresponding to the five roller members 41b of the drive roller 41 described above.

  The sealing belt 13 is formed in an endless shape (endless), and is stretched around the driving roller member 41b and the driven roller member 42b. As shown in FIG. 2, the sealing belt 13 rotates forward (endless movement) in the direction of arrow R13 as the driving roller 41 rotates in the direction of arrow R41 by a sealing motor (stepping motor) 46 as driving means. In addition, as the sealing motor 46 rotates in the reverse direction, it rotates in the direction opposite to the direction of the arrow R13.

  5A, 5B, and 5C are development views of the sealing belt 13. FIG. Among these, (a) is a figure which shows the inner peripheral surface 13a side (back surface side), (b) is the figure which looked at the sealing belt 13 from the lower side in (a), (c) is ( The figure which shows the XX arrow directional view in a). As shown in FIGS. 2 to 5, the sealing belt 13 includes an endless belt main body 13 </ b> A and a cleaning unit 43 (43 a, 43 a, 43) sequentially provided along the circumferential direction on the inner peripheral surface 13 a side thereof. 43b, 43c, 43d), a sealing portion 44 (44a, 44b, 44c, 44d), and an opening 45 (45a, 45b, 45c, 45d). The cleaning unit 43, the sealing unit 44, and the opening 45 are equally spaced along the width direction of the sealing belt 13 (hereinafter referred to as “belt width direction” as appropriate, which is the same as the sheet conveying direction). 4 sets are provided, and the positions in the belt width direction of the respective sets correspond to the ink jet heads 12a, 12b, 12c, and 12d, respectively. Note that each of the cleaning unit 43, the sealing unit 44, and the opening 45 of each group has the same configuration, and is different only in the position in the belt width direction.

  Here, in the present embodiment, the sealing belt 13 will be described as an example in which the belt main body 13A, the cleaning unit 43, and the sealing unit 44 are integrally formed. In addition, as a material of the sealing belt 13, rubber members, such as EPDM and NBR, can be used, for example.

  As shown in FIGS. 5A, 5B, and 5C, the cleaning portion 43 is formed in a rectangular blade shape, and the inner peripheral surface 13a of the sealing belt 13 with one side facing the belt width direction. Is erected. As shown in FIG. 5, the cleaning unit 43 is formed such that its width W is longer than the length of the nozzle surface N of the inkjet head 12 in the sheet conveying direction, and as shown in FIG. 2, the inner peripheral surface 13a. The protrusion height H from is set to about 3 mm, for example. On the other hand, the distance from the inner peripheral surface 13a of the sealing belt 13 of the nozzle surface N of the inkjet head 12 when it is disposed at the retracted position shown in FIG. 2 is set to about 2 mm. Accordingly, when the sealing belt 13 is rotated in the direction of the arrow R13 in a state where the nozzle surface N of the inkjet head 12 is located at the retracted position, the cleaning portion 43 described above overlaps the nozzle surface N. It is rubbed in an elastically curved state with 1 mm (= 3 mm−2 mm). Thereby, the ink adhering to the nozzle surface N that has been subjected to the water repellent finish can be wiped off without scraping off the water repellent finish.

  As shown in FIG. 5, each sealing part 44 (44a) is comprised by the frame-shaped bank part 47a and the recessed part 47b inside that are long in the circumferential direction of the sealing belt 13. As shown in FIG. The bank portion 47a has a length in the circumferential direction and a length in the belt width direction that are set smaller than the nozzle surface N of the inkjet head 12, and the nozzle surface N is pressed when the nozzle surface N is pressed against the bank portion 47a. The nozzle formed on the surface N is positioned inside the bank portion 47a. That is, the bank portion 47a can seal the nozzle when pressed against the nozzle surface N. At this time, the above-described guide plate 26 serves as a reaction force element, and the conveyance belt 23 and the sealing portion 44 of the sealing belt 13 are sandwiched between the guide plate 26 and the nozzle surface N. Thereby, the nozzle surface N can be reliably sealed, and the drying and solidification of the ink near the nozzle can be effectively prevented. As shown in FIG. 2, the protruding height of the sealing portion 44 from the inner peripheral surface 13a of the sealing belt 13 is the same as the nozzle surface N when the nozzle surface N of the inkjet head 12 is disposed at the retracted position. The distance between the inner peripheral surface 13a of the sealing belt 13 is set to be smaller. Thereby, when the nozzle surface N is disposed at the retracted position, the sealing portion 44 can pass through the printing portion P without interfering with the nozzle surface N as the sealing belt 13 rotates.

  As shown in FIG. 5, the opening 45 has a rectangular shape that is long in the circumferential direction of the sealing belt 13, and the outer circumferential surface 13 b side and the inner circumferential surface 13 a side of the sealing belt 13 are in the thickness direction of the sealing belt 13. It is formed so as to penetrate through. The circumferential length of the opening 45 and the length in the belt width direction are set to be larger than those of the nozzle surface N of the inkjet head 12. Thereby, the inkjet head 12d at the time of printing can perform printing on the sheet material S conveyed to the printing unit P at the printing position where the nozzle surface N protrudes downward from the opening 45. It has become.

  The above-described sealing belt 13 is rotationally driven by a sealing motor 46 (see FIG. 2). As shown in FIG. 5, a through hole 13 c that penetrates the sealing belt 13 in the thickness direction is formed near the end in the width direction of the sealing belt 13. The through hole 13c is detected by a light transmission type sensor 13d. For example, when the sensor 13d detects the through hole 13c in the state of the sealing belt 13 shown in FIG. 3, it is assumed that the sealing portion 44 of the sealing belt 13 is at the home position where the printing portion P is disposed. . Then, when the motor 46 rotates a predetermined number of times from this state, the cleaning unit 43 wipes the adhering ink by rubbing the nozzle surface N of the inkjet head 12, and the opening 45 It is arranged in the printing part P.

  In the present embodiment, as described above, a set of each cleaning unit 43, sealing unit 44, and opening 45 is aligned in a row in the circumferential direction, and four sets are arranged in the belt width direction. Yes. These four sets pass between the roller members 21b adjacent to each other of the driving roller 21 and between the roller members 22b adjacent to each other of the driven roller 22 as the sealing belt 13 rotates. It is like that. Therefore, the sealing belt 13 can be stretched evenly with substantially the same tension distribution in the belt width direction by the five roller members 21b and 22b. For this reason, each nozzle surface N can be reliably sealed by each sealing portion 44, and each nozzle surface N can be rubbed satisfactorily by each cleaning portion 43.

  The inkjet recording apparatus 10 configured as described above operates as follows.

  In the state in which the main power supply (not shown) is turned off, the inkjet recording apparatus 10 takes the home position where the sealing belt 13 is disposed in the printing portion P, as shown in FIG. Further, the inkjet head 12 takes a sealing position (home position) in which the nozzle surface N is disposed at the sealing position and sealed by the sealing portion 44. That is, when the inkjet recording apparatus 10 is not used, the nozzle surface N of the inkjet head 12 is sealed by the sealing portion 44 of the sealing belt 13.

  When the main power supply of the ink jet recording apparatus 10 is turned on, as shown in FIG. 4, the cam 35 is rotated by the elevating motor 36 of the elevating means 34, the entire head unit 33 is raised by this rotation, and the nozzle surface N is shown in FIG. 2 is disposed at the retracted position. Thereby, the sealing of the nozzle surface N is released, and the nozzle surface N is separated from the sealing portion 44. Subsequently, the sealing belt 13 is rotated in the direction of the arrow R13 in FIG. 2 by the rotation of the sealing motor 46, and the opening 45 of the sealing belt 13 is disposed in the printing portion P. Furthermore, the sheet material S is conveyed to the printing unit P by the rotation of the conveyance belt 23 by the rotation of the conveyance motor 27, and the ink jet head 12 performs ink ejection. In the idle ejection, prior to printing by the ink jet head 12, the ink is ejected onto the sheet material S by ejecting ink from the nozzle in a state where the nozzle surface N is disposed at the retracted position, and drying and solidifying in the vicinity of the nozzle. This is done to spit out. After the idle discharge, the conveying belt 23 is rotated to discharge the sheet material S from the printing unit P. Thereafter, the sealing belt 13 is rotated in the direction of the arrow R13 by the sealing motor 46, and the nozzle surface N is rubbed and wiped by the cleaning unit 43. After the ink is wiped off, the sealing motor 46 is rotated in the reverse direction, the sealing belt 13 is rotated in the direction opposite to the arrow R13 direction, and the opening 45 is disposed in the printing portion P again. Further, the lifting / lowering motor 36 is reversed, the head unit 33 is lowered by the cam 35, and the nozzle surface N is set to a printing position that provides a predetermined clearance with respect to the sheet material carrying surface 23 a on the forward side A of the conveying belt 23. Deploy. Thus, the preparation for printing by the inkjet head 12 is completed.

  When the user presses a print start button (not shown) by an operation unit (not shown) of the inkjet recording apparatus 10, the conveyance belt 23 is rotated and the sheet material S conveyed from the upstream side is carried on the surface of the conveyance belt 23. And conveyed to the printing unit P. When the sheet material S passes through the printing portion P, yellow, magenta, cyan, and black inks are ejected in this order by the ink jet heads 12a, 12b, 12c, and 12d, and printing is performed for each color. The sheet material S that has passed through the printing section P is printed in four colors, and is further conveyed downstream to be discharged outside the main body of the inkjet recording apparatus. Thereby, the four-color full-color printing on one side of one sheet material S is completed.

  After the printing is completed, the head unit 33 is raised by the rotation of the cam 35 accompanying the rotation of the elevating motor 36, and the nozzle surface N is disposed at the retracted position as shown in FIG. Subsequently, by the rotation of the sealing motor 46, the sealing belt 13 is rotated in the direction of the arrow R13 in FIG. 2, and the cleaning unit 43 rubs the nozzle surface N from the right end to the left end in FIG. Wipe ink adhering to. Thereafter, the sealing belt 44 is further rotated in the same direction, so that the sealing portion 44 is disposed in the printing portion P. The lift motor 36 is rotated, the head unit 33 is lowered by the cam 35, and the nozzle surface N is disposed at the sealing position. Thereby, the nozzle of each nozzle surface N can be sealed in a sealed state by each sealing portion 44.

  According to the present embodiment, as shown in FIG. 2, when the opening 45 is arranged in the printing part P, the sealing part 44 is substantially entirely overlapped above the printing part P, ie, the opening. It arrange | positions so that the upper part of the part 45 may overlap. In other words, when the opening 45 is arranged in the printing part P, the sealing part 44 almost entirely overlaps the opening 45 when viewed from the direction orthogonal to the nozzle surface N. It is. On the contrary, as shown in FIG. 3, when the sealing portion 44 is disposed in the printing portion P, the opening portion 45 is substantially entirely overlapped above the printing portion P, that is, the sealing portion. 44 so as to overlap above 44.

  As described above, when one is used, the other is not used, and when the sealing portion 44 and the opening 45 are arranged in the printing portion P, the other is one. Therefore, the area of the entire sealing belt 13 in the top view, that is, the occupied area can be reduced. That is, even when the sealing belt 13 that can clean or seal the nozzle surface N of the inkjet head 12 is provided, an increase in the occupied area due to this can be suppressed. . Note that the almost complete overlap means that, for example, the sum of the occupied areas of the two in the top view is the smallest, and more specifically, when one of the two is disposed on the printing portion P, This corresponds to the case where the center in the belt movement direction coincides with the center in the other belt movement direction. Further, in the present embodiment, the head unit 33 having the four inkjet heads 12 can be accommodated almost inside the sealing belt 13, so that the occupied area in the vertical direction due to the provision of the sealing belt 13 is reduced. The increase can also be suppressed. Furthermore, in the present embodiment, since the rotation direction of the sealing belt 13 is set to the nozzle arrangement direction of each inkjet head 12, each of the cleaning units 43a, 43b, 43c, and 43d is individually provided for each inkjet head. The nozzle surfaces N of 12a, 12b, 12c, and 12d are rubbed to wipe off the adhering ink. That is, since the nozzle surface N is cleaned by the dedicated cleaning unit 43 for each color, unlike the case where the cleaning member is applied to the above-described invention of Patent Document 2, the cleaning unit 43 wipes nozzles of different colors. Ink color mixing due to the ink can be prevented.

  As described above, according to the present embodiment, an increase in the occupied area due to the provision of the sealing unit can be suppressed, and color mixing of ink by the cleaning unit can be effectively prevented.

  Further, in the present embodiment, since the sealing belt 13, the driving roller 41, the driven roller 42 and the like around which the sealing belt 13 is stretched can be arranged above the printing portion P, the printing portion P Also, maintenance of the conveying means 11 such as the conveying belt 23, the driving roller 21, and the driven roller 22 located on the lower side is facilitated.

  In the above description, when one of the sealing portion 44 and the opening 45 is disposed in the printing portion P, the other is almost completely overlapped with the other, so that the occupied area is reduced. Although the increase is suppressed to the maximum, it may be configured so that at least a part thereof overlaps instead. However, an increase in the occupied area as a whole can be suppressed as the overlapping area is larger.

  As the lifting means 34, instead of using the cam 35, for example, a feed screw (not shown) is arranged vertically on the main body of the ink jet recording apparatus, and a nut member (not shown) is screwed to the feed screw. ) On the head unit 33 side, and the head unit 33 can be moved up and down by forward and reverse rotation of the feed screw.

  Further, as indicated by a broken line in FIG. 5, the cleaning unit 43A may be configured to have an angle with respect to the belt width direction. When the cleaning unit 43A inclined in this way is used, when the nozzle surface N is rubbed by the cleaning unit 43A, the wiped dry ink is positively moved in a direction to gradually move away from the nozzle. be able to. Further, the four cleaning portions 43 may be provided at different positions in the circumferential direction of the sealing belt 13. In this case, compared to the case where the four cleaning units 43 are rubbed against the nozzle surfaces N as shown in FIG. The sliding resistance by the four cleaning parts 43 can be prevented from acting simultaneously, the load on the sealing motor 46 due to torque fluctuation can be reduced, and the endless movement of the sealing belt 13 can be enabled. .

<Embodiment 2>
FIG. 6 shows an inkjet recording apparatus 10A according to this embodiment. This figure shows a state in which the sealing portion 54 of the sealing belt 63 is disposed in the printing portion P.

  In the first embodiment, the example in which the sealing belt 13, the driving roller 41, the driven roller 42, and the like are arranged above the printing unit P has been described. On the other hand, in the second embodiment, an example in which the sealing belt 63, the driving roller 51, and the driven roller 52 are arranged below the printing unit P will be described.

  As shown in FIG. 6, the transport unit 11 and the head unit 33 including the ink jet head 12 are the same as those in the first embodiment described above, and a description thereof will be omitted.

  In the present embodiment, a driving roller 51 having a shaft 51a directed in the sheet conveying direction is disposed in the vicinity of one end of the conveying belt 23 in the sheet passing width direction, and the shaft 52a is conveyed in the vicinity of the other end. A driven roller 52 directed in the direction is disposed, and a sealing belt 63 is stretched over the driving roller 51 and the driven roller 52. In the present embodiment, unlike the cleaning portion 43 and the sealing portion 44 provided on the inner peripheral surface side of the sealing belt 13 in the first embodiment, the outer peripheral surface 63b side of the sealing belt 63 is provided. Is provided. Thereby, in this embodiment, the cleaning part 53 and the sealing part 54 do not interfere with the driving roller 51 and the driven roller 52. Therefore, the driving roller 51 and the driven roller 52 can be configured by a single cylindrical roller member that is long in the axial direction. Therefore, the tension distribution can be made more uniform than in the first embodiment along the belt width direction of the sealing belt 63, and the endless movement of the sealing belt 63 can be stabilized correspondingly, and the cleaning unit Good cleaning of the nozzle surface N by 53 can be performed.

  Further, in the present embodiment, unlike the first embodiment, the sealing belt 63 does not surround the head unit 33, so that operations such as maintenance of the inkjet head 12 are facilitated.

  The sealing belt 63 according to this embodiment is manufactured in the same manner as the sealing belt 13 of the first embodiment described above, and then applied to the present embodiment by reversing the front and back during assembly. Can be made.

  Moreover, in the above Embodiment 1, although the case where the whole sealing belt 13 was integrally molded was demonstrated to the example, this invention is not necessarily limited to this. That is, the belt main body 13A having the opening 45, the cleaning unit 43, and the sealing unit 44 may be formed separately, and may be integrally configured as a whole by bonding or the like. In this case, it is possible to select optimum materials for the belt main body 13A, the cleaning unit 43, and the sealing unit 44 individually. The same applies to the second embodiment.

FIG. 2 is a diagram of the ink jet recording apparatus according to Embodiment 1 viewed from above. It is a figure when the ink jet recording apparatus is viewed from the downstream side in the transport direction from the upstream side, and shows a state in which the nozzle surface of the ink jet is disposed at the retracted position and the opening of the sealing belt is disposed at the printing unit. It is a figure explaining. It is a figure when the upstream side of the inkjet recording apparatus is viewed from the downstream side in the transport direction, in which the sealing part of the sealing belt is arranged in the printing part and the nozzle surface of the inkjet head is arranged in the sealing position FIG. It is the longitudinal cross-sectional view which looked at the inkjet recording device from the left side. (A) is the figure which looked at the sealing belt of the developed state from the inner peripheral surface side. (B) is the figure which looked at the sealing belt from the downward direction in (a). (C) is a XX arrow directional view in (a) of a sealing belt. FIG. 10 is a diagram of the ink jet recording apparatus according to the second embodiment when viewed from the downstream side to the upstream side in the transport direction, in which the nozzle surface of the ink jet head is disposed at the retracted position, and the sealing portion of the sealing belt is the printing portion It is a figure explaining the state arrange | positioned.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10,10A ... Inkjet recording apparatus, 11 ... Conveyance means, 12, 12a, 12b, 12c, 12d ... Inkjet head, 13, 63 ... Sealing belt, 13a ... Inner peripheral surface, 34 ... Elevating means 43, 43a, 43b, 43c, 43d, 53... Cleaning part, 44, 44a, 44b, 44c, 44d, 54... Sealing part, 45, 45a, 45b, 45c, 45d, 55. 63b: Outer peripheral surface, Ks: Sheet material conveyance direction, N: Nozzle surface, P: Printing section, S: Sheet material

Claims (5)

In an inkjet recording apparatus that performs printing by spraying ink from a plurality of nozzles formed on a nozzle surface facing the printing unit, on a sheet material conveyed to a printing unit by a conveying unit,
An inkjet head having a plurality of the nozzles arranged in the sheet passing width direction substantially orthogonal to the sheet material conveying direction;
A sealing unit having a sealing belt that moves endlessly in the paper width direction through the printing unit,
The inkjet head is arranged in a plurality of rows along the sheet material conveying direction and ejects ink of different colors for each row from the plurality of nozzles,
The sealing belt is located at different positions in the circumferential direction.
A cleaning portion that is rubbed against the nozzle surface as the sealing belt moves endlessly;
A sealing part that seals the nozzle surface when arranged in the printing part;
An opening that penetrates the sealing belt in the front and back direction and allows the ink to be ejected from the nozzles to the sheet material when disposed in the printing unit;
When one of the sealing portion and the opening is disposed in the print portion, the other is overlapped with the other when viewed from a direction perpendicular to the nozzle surface. ,
An ink jet recording apparatus. The cleaning portion and the sealing portion are provided on the inner peripheral surface side of the sealing belt, and the inkjet head is disposed on the inner side of the sealing belt.
The inkjet recording apparatus according to claim 1. The cleaning portion and the sealing portion are provided on the outer peripheral surface side of the sealing belt, and the sheet material conveyed by the conveying means is conveyed so as to penetrate the inner side of the sealing belt.
The inkjet recording apparatus according to claim 1. Elevating means for elevating and lowering the plurality of inkjet heads;
The elevating means seals the nozzle surface of the ink jet by lowering and pressing the plurality of ink jet heads against a sealing portion arranged in the printing portion.
The inkjet recording apparatus according to any one of claims 1 to 3, wherein In the sealing belt, the cleaning portion and the sealing portion are integrally formed of an elastic member.
The ink jet recording apparatus according to claim 1, wherein the ink jet recording apparatus is provided.

Images