JP4027833B2 - Inkjet printing system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an inkjet printing system that performs printing by ejecting ink onto a predetermined printing medium.
[0002]
[Prior art]
In recent years, ink jet printers that perform printing by ejecting ink onto a predetermined printing medium have become widespread for personal use and business use. In such an ink jet printer, it is necessary to stabilize the paper transport in order to stabilize the landing position of the ejected ink on the print medium in order to improve the quality, but it is desirable to stabilize the paper transport with a simple configuration. It is.
[0003]
FIG. 6 shows a configuration diagram of a conventional inkjet printing system. An inkjet printing system 101 shown in FIG. 6A is for general business use. In the printing unit 102, row nozzles 103 in which a predetermined number of individual nozzles are arranged on a straight line are separated by color at intervals of 50 mm, for example. Five rows of nozzles 103A to 103E are arranged for the same color. Further, feed rollers 104 to 107 are disposed on the nozzle surface side of the printing unit 102, and the feed rollers 105 and 106 are disposed in proximity to the nozzle surface. Then, printing is performed by ejecting ink from the row nozzles 103A to 103E onto the continuous paper 108 which is a printing medium conveyed by the feed rollers 104 to 107.
[0004]
In the ink jet printing system 101, the printing portion of the continuous paper 108 is printed between the two feed rollers 105 and 106, and therefore the continuous paper 108 flutters up and down and meanders. When fluttering occurs, the ink ejected from each row nozzle 103A to 103E and landed on the continuous paper 108 should be a constant distance between the nozzles 103A to 103E, but causes an interval in the transport direction (described later). (See FIG. 4B). In addition, when meandering occurs, the landing positions at both ends in the width direction on the continuous paper 108 are shifted (see FIG. 4C described later).
[0005]
Therefore, an inkjet printing system described in the following patent document is known as a system that avoids flapping in the vertical direction when the continuous paper 108 is conveyed.
[0006]
[Patent Document 1]
Japanese translation of PCT publication No. 2001-500441
The ink jet printing system 111 shown in FIG. 6B is the one shown in FIG. 8B of the above-mentioned patent document. The feed rollers 112, 113, 114A to 114F are arranged in an arc shape and face the feed rollers 114A to 114F. The separate row nozzles 115A to 115F are arranged in an arc shape having the same curvature. That is, the continuous paper 116 as a printing medium is conveyed in an arc shape between the feed rollers 112, 113, 114A to 114F and is brought into contact with each of the feed rollers 114A to 114F. The landing positions are stabilized by ejecting ink with the row nozzles 115A to 115F.
[0008]
[Problems to be solved by the invention]
However, in the inkjet printing system 111 disclosed in the above-mentioned patent document, there is a problem that the continuous paper 108 has a slight contact with each of the separate row nozzles 115A to 115F, and the meandering phenomenon remains. In addition, separate row nozzles 115A to 115F must be arranged, and the existing printing unit as shown in FIG. 6A cannot be applied as it is. There is a problem of inviting. Further, if each of the row nozzles 115A to 115F does not have the same ink discharge distance, the print quality is not maintained, and the same curvature as the arc shape of the continuous paper 108, that is, the center point of the circle including the arc. There is a problem that the discharge nozzles must be arranged at equal distances, and the arrangement adjustment is difficult.
[0009]
The present invention has been made in view of the above problems, and an object of the present invention is to provide an inkjet printing system that can stabilize the conveyance of a printing medium with a simple configuration without changing an existing inkjet printing unit.
[0010]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, in the invention of claim 1, an inkjet printing system that performs printing by ejecting ink onto a predetermined continuous print medium transported by a transport unit, the individual nozzles that eject ink are provided as described above. An inkjet printing unit in which a predetermined number of row nozzles arranged in the width direction of the continuous print medium are linearly arranged at predetermined intervals in the transport direction of the continuous print medium, and individual row nozzles in the inkjet print unit at least it has a length corresponding to the nozzle, and printing support rollers to eject ink from the corresponding said row nozzle portion for supporting the continuous printing medium is positioned a predetermined number to be opposed to each column nozzles, each print is a between the support rollers are arranged on the opposite side of the ink jet printing unit the continuous printing alternately with the print support rollers Body was suspended, the tension of the continuous printing medium on the printing support roller configured to have a, a tension roller to adjust the position of the opposite side of the ink jet printing unit.
[0011]
In the inventions of claims 2 and 3 , "the tension roller has a configuration in which a portion corresponding to an ink ejected region of the continuous print medium to be conveyed is formed with a smaller diameter than both ends",
“A part or all of the tension roller in a free state that moves up and down by its own weight according to the tension of the continuous print medium, a position detection unit that detects a position of the tension roller in the free state, and a position detection unit by controlling the take-up rotation of the conveyance means based on the position detection, and a control means for maintaining the tension of the continuous printing medium on the tension roller the back of the set position the print support rollers It is a configuration.
[0012]
As described above, the print support roller is arranged so as to face each linearly arranged nozzle of the ink jet print unit, and the tension of the continuous print medium supported by the print support roller is set between the print support rollers. A tension roller that is placed on the opposite side of the inkjet printing unit and suspended continuously with the printing support roller and alternately supports the area that is supported by adjusting the arrangement position on the opposite side of the inkjet printing unit. Ink is discharged from the row nozzles to perform printing. In other words, since the print support roller corresponding to each row nozzle is arranged and ink is ejected on the continuous print medium of the support portion whose tension is adjusted by the tension roller, the existing inkjet printing in which each row nozzle is arranged linearly Without changing the portion, it is possible to avoid the fluttering and meandering of the print medium with a simple configuration, and to stabilize the print medium. As a result, it is possible to improve the print quality.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. The “printing” used in the description of the inkjet printing system of the present invention means not only printing of characters but also printing of images and the like, and includes the concept of printing.
[0014]
FIG. 1 shows a configuration diagram of an inkjet printing system according to the first embodiment of the present invention. FIG. 1A is a configuration diagram of a main part of an ink jet printing system, and FIG. 1B is a conceptual explanatory diagram of an ink ejection surface of an ink jet printing unit. In FIG. 1A, an inkjet printing system 11 includes an inkjet printing unit 12, and row nozzles 13A to 13E are linearly arranged on the discharge surface thereof in the conveyance direction of a continuous sheet described later.
[0015]
That is, the inkjet printing unit 12 has an existing configuration that has been known for a long time, and as shown in FIG. 1B, a predetermined number of individual nozzles that eject ink are arranged in the width direction of a continuous sheet to be described later. For example, the row nozzles 13A to 13E are linearly arranged in, for example, 5 rows at intervals of 50 mm in the conveyance direction of the continuous paper. For example, the row nozzle 13A is for yellow ink, the row nozzle 13B is for magenta ink, the row nozzle 13C is for cyan ink, the row nozzle 13D is for light cyan ink, and the row nozzle 13E is for black ink so as to correspond to multicolor printing. . Note that the printing speed can be improved by setting all the row nozzles 13A to 13E to the same color (for example, black).
[0016]
Feed rollers 14 and 15 are disposed in the vicinity of both ends of the ink jet printing unit 12 in the paper conveyance direction, and print support rollers 16A to 16E and tension rollers 17A to 17D are disposed between the feed rollers 14 and 15, and between these rollers. The continuous paper 18 that is a continuous print medium is conveyed by being suspended. Note that the continuous paper 18 is omitted from the supply source of the continuous paper 18 (see FIG. 5). Further, a timing mark (see FIG. 3) is provided on the back surface of the continuous paper 18 to be conveyed, for example, and a sensor 19 for detecting the timing mark is disposed, for example, below the front stage of the feed roller 14.
[0017]
The print support rollers 16A to 16E have at least a length corresponding to the individual nozzles of the row nozzles in the inkjet printing unit 12 (a length constituted by a predetermined number of individual nozzles in FIG. 1B). Five rows are arranged linearly at equal distances facing 13A to 13E, and ink is ejected from corresponding row nozzles at a portion that supports continuous paper 18 (portion that faces each row nozzle 13A to 13E). The print support rollers 16A to 16E are rotatably fixed to a shaft, and, for example, do not transmit a rotational driving force, and rotate appropriately due to friction during conveyance of the continuous paper 18.
[0018]
For example, four tension rollers 17A to 17D are arranged below the print support rollers 16A to 16E. Here, the tension rollers 17A to 17D are rotatably fixed to a shaft and appropriately rotated by friction when the continuous paper 18 is conveyed. That is, the tension of the continuous paper 18 supported by the print support rollers 16A to 16E is adjusted at the arrangement positions (vertical direction in the drawing) of the tension rollers 17A to 17D. As a result, flapping and meandering during conveyance of the continuous paper 18 supported by the print support rollers 16A to 16E can be avoided.
[0019]
Here, FIG. 2 is an explanatory view of each roller shape in the inkjet printing system of FIG. FIG. 12A shows the print support roller 16A (16B to 16E), in which a cylindrical body 22 is rotatably supported by a shaft 21 by a bearing or the like. The feed roller 14 has the same configuration.
[0020]
FIG. 2B shows the tension roller 17A (17B to 17D). A cylindrical body 24 is rotatably supported on the shaft 21 by, for example, a bearing. The body portion 24 is composed of body end portions 24A and 24A at both ends thereof and a small diameter portion 24B having a smaller diameter. The small diameter portion 24B is for avoiding contact with the landing ink portion of the continuous paper 18 printed on the preceding print support rollers 16A to 16E, and is formed with a length corresponding to the print width. . The feed roller 15 has the same configuration.
[0021]
Next, FIG. 3 shows an explanatory diagram of a printing state on a roller by the ink jet printing system of FIG. In FIG. 3, a continuous paper 18 conveyed by a conveying means (not shown) between the supply source and the winding unit (see FIG. 5) is sent from the feed roller 14 via the print support rollers 16 </ b> A to 16 </ b> E and the tension rollers 17 </ b> A to 17 </ b> D. And suspended on the feed roller 15. Here, the tension applied to the continuous paper 18 on the print support rollers 16A to 16E is adjusted by the arrangement positions of the tension rollers 17A to 17D. For example, a timing mark 31 is provided in advance on the back surface of the continuous paper 18 for taking a printing timing for each length of a continuous sheet 18 for example.
[0022]
Therefore, when the timing mark 31 is detected by the sensor 19 for the continuous paper 18 conveyed at a constant speed, the row nozzle 13A of the ink jet printing unit 12 is supported on the print support roller 16A after a predetermined time from the detection. Ink is ejected onto the continuous paper 18 on the basis of predetermined print data. Further, after a predetermined time (may be the total time since the detection of the timing mark 31), the portion supported by the print support roller 16B on the continuous paper 18 conveyed through the tension roller 17A is based on the print data. Then, ink is ejected from the row nozzle 13B.
[0023]
Similarly, printing is performed by sequentially ejecting ink onto a portion of the continuous paper 18 that is supported by the print support rollers 16 </ b> C to 16 </ b> E, and is wound around a winding unit (not shown) via the feed roller 15. In this case, as described above, the tension rollers 17A to 17D and the feed roller 15 are not in contact with the portion where the ink has landed as shown in FIG. Absent.
[0024]
FIG. 4 is an explanatory diagram of the landing ink state by the ink jet printing system of FIG. 4A to 4C show the state of the landing ink 41 on the continuous paper 18 at the time of printing, and each row in the vertical direction in the figure corresponds to the row nozzles 13A to 13E. That is, as shown in FIGS. 1 to 3, the print support rollers 16 </ b> A to 16 </ b> E corresponding to the respective row nozzles 13 </ b> A to 13 </ b> E are arranged and the tension is adjusted by the tension rollers 17 </ b> A to 17 </ b> D. Since flapping and meandering on the print support rollers 16A to 16E are avoided, the landing ink 41 on the continuous paper 18 is aligned vertically as shown in FIG. Can be made constant.
[0025]
Incidentally, if the continuous paper 18 flutters in the respective row nozzles 13A to 13E, as shown in FIG. 4B, the landing ink 41 becomes dense or sparse between predetermined rows. When meandering occurs, the landing ink 41 undulates in the vertical direction as shown in FIG. That is, flapping and meandering of the continuous paper 18 are avoided, and the landing inks 41 are aligned vertically as shown in FIG.
[0026]
In this way, without changing the existing inkjet printing unit 12 in which the row nozzles 13A to 13E are linearly arranged, it is possible to avoid paper flapping and meandering with a simple configuration and to stabilize it, As a result, the print quality can be improved.
[0027]
Next, FIG. 5 shows a configuration diagram of an inkjet printing system according to the second embodiment of the present invention. In the inkjet printing system 11 shown in FIGS. 5A and 5B, the configuration and arrangement of the inkjet printing unit 12, the feed rollers 14 and 15, and the print support rollers 16A to 16E are the same as those in FIG. Therefore, among the tension rollers 17A to 17D, for example, the tension rollers 17B and 17C are not supported and are in a free state (a single tension roller may be used).
[0028]
In this case, when the tension rollers 17B and 17C in the free state are lowered downward by their own weight due to the slack of the continuous paper 18 being conveyed, the conveyance stroke is extended between the print support rollers 16C and 16D, and printing by the row nozzles 13C and 13D is performed. Timing will shift. Accordingly, the tension rollers 17B and 17C are provided with position detection means 51A and 51B, and the winding unit 52 as a transport unit controls rotation of the winding unit 52 according to the position detection of the position detection unit 51. The rotation control means 53 which is a control means to perform is provided.
[0029]
That is, as shown in FIG. 5A, when the continuous paper 18 wound and conveyed by the winding unit 52 is loosened, the tension rollers 17B and 17C are lowered, and the position detection means 51A and 51B detect the positions thereof. . Therefore, as shown in FIG. 5B, the rotation control unit 53 increases the tension with respect to the continuous paper 18 by increasing the rotation of the winding unit 52 in accordance with the position detection of the position detection units 51A and 51B. Thus, the tension rollers 17B and 17C are returned to the initial set positions.
[0030]
As a result, the tension of the continuous paper 18 supported by the print support rollers 16A to 16E is maintained. Conversely, when the tension of the conveyed continuous paper 18 increases, the tension rollers 17B and 17C are raised, and the position detection means 51A and 51B detect the raised positions so that the rotation control means 53 takes up the winding unit 52. The tension is reduced with respect to the continuous paper 18 so as to reduce the rotation of the paper, and the tension rollers 17B and 17C are returned to the initial set positions.
[0031]
Thus, by maintaining the tension of the continuous paper 18 being conveyed on the print support rollers 16A to 16E, meandering or the like due to the slack of the continuous paper 18 can be avoided. Without changing the existing inkjet printing unit 12 in which the nozzles 13A to 13E are linearly arranged, paper conveyance can be stabilized with a simple configuration, and as a result, the printing quality can be improved.
[0032]
【The invention's effect】
As described above, according to the present invention, opposite each row nozzles linearly arranged in the ink jet printing unit the print support rollers arranged, the tension of the continuous printing medium is supported by the print support rollers, A tension roller that is arranged between the print support rollers and on the opposite side of the inkjet print unit and suspends the continuous print medium alternately with the print support roller, and is adjusted according to the arrangement position on the opposite side of the inkjet print unit. By causing ink to be ejected from the corresponding row nozzle in the supported area, printing can be performed with a simple configuration without changing the existing inkjet printing unit in which each row nozzle is linearly arranged. Stabilization can be achieved, and as a result, printing quality can be improved.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of an inkjet printing system according to a first embodiment of the present invention.
FIG. 2 is an explanatory diagram of each roller shape in the ink jet printing system of FIG.
3 is an explanatory diagram of a printing state on a roller by the ink jet printing system of FIG. 1; FIG.
4 is an explanatory diagram of a landing ink state by the ink jet printing system of FIG. 1; FIG.
FIG. 5 is a configuration diagram of an inkjet printing system according to a second embodiment of the present invention.
FIG. 6 is a configuration diagram of a conventional inkjet printing system.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 11 Inkjet printing system 12 Inkjet printing part 13 Row nozzles 14, 15 Feed roller 16 Printing support roller 17 Tension roller 18 Continuous paper 19 Sensor 31 Timing mark 41 Landing ink 51 Position detection means 52 Winding part 53 Rotation control means

Claims (3)

An ink jet printing system that performs printing by discharging ink onto a predetermined continuous print medium conveyed by a conveying means,
An inkjet printing unit in which a predetermined number of row nozzles in which a predetermined number of individual nozzles that eject ink are arranged in the width direction of the continuous print medium are linearly arranged at predetermined intervals in the transport direction of the continuous print medium;
The inkjet printing unit has at least a length corresponding to the individual nozzles of the row nozzles, and a predetermined number of the nozzles are arranged so as to face each row nozzle and support the continuous print medium. A print support roller to be discharged;
Wherein respectively disposed on the opposite side of the ink jet printing unit A between the print support rollers by suspending the continuous printing medium alternate with the printing support rollers, the tension of the continuous printing medium on the printing support rollers A tension roller that adjusts the position at the opposite side of the inkjet printing section ;
An inkjet printing system comprising: 2. The ink jet printing system according to claim 1, wherein the tension roller is formed such that a portion corresponding to an ink ejected area of the continuous print medium to be conveyed is smaller in diameter than both ends. . An ink jet printing system according to claim 1 or 2,
The tension roller is in a free state in which a part or all of the continuous print medium moves up and down by its own weight according to the tension of the continuous print medium ;
Position detecting means for detecting the position of the tension roller in the free state;
Control for maintaining the tension of the continuous print medium on the print support roller by returning the tension roller to a set position by controlling the winding rotation of the transport means based on the position detection of the position detection means. Means,
An inkjet printing system comprising:

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