JP3885405B2 - INKJET PRINTING APPARATUS AND METHOD FOR DETERMINING PRINTED FABRIC - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a printing technique for printing a cloth, for example, an ink jet color image processing technique for printing by spraying a plurality of colors of ink onto the cloth by an ink jet method.
[0002]
[Prior art]
2. Description of the Related Art In recent years, ink jet printing apparatuses are rapidly spreading as industrial, office, and personal printers because digital images can be easily colored. Under such circumstances, application of inkjet printing apparatuses to textile printing is expected.
[0003]
By the way, as a typical example of conventional printing, there is a silk screen printing method. In this method, a screen plate is prepared for each color used in the original image to be printed, and the printing paste is passed through the screen plate and transferred directly to the fabric for dyeing. . However, this method requires a great amount of man-hours for producing a screen plate for each color, and also requires a large amount of fabric to be prepared by preparing a dyeing paste for each color used in the original image. Although it is suitable for printing a single item at a time, for example, when printing a small lot of clothing, there is a disadvantage that the cost per product is relatively increased.
[0004]
In contrast to the conventional textile printing method, according to the ink jet printing method, the ink type provided in the printing apparatus is controlled by a digital signal, and small droplets of ink are landed and formed on the medium in a mixed manner. Thus, an image can be directly formed. Accordingly, it is not necessary to prepare screen paste or printing paste for each color, and the man-hours can be greatly reduced, so that even a small lot of products can be printed at low cost.
[0005]
[Problems to be solved by the invention]
By the way, for example, when printing an image on a paper by an ink jet method, the thickness of the normal paper is constant around 100 μm, and therefore image misalignment based on the conveyance variation can be accommodated by a relatively simple adjustment. It will not be. On the other hand, since the thickness of the cloth varies extremely from several hundred μm to about 5 mm, when printing an image on the cloth by an ink jet method, the following conveyance variation becomes a problem.
[0006]
When printing an image on a cloth by an ink jet method, the head is moved once in a direction perpendicular to the cloth conveyance direction while ejecting ink from the nozzle. An image is formed in such a manner as to be moved.
[0007]
However, when the fabric to be printed is wound around the transport roller and transported, even if the rotation angle of the transport roller is constant, the roller diameter becomes substantially larger as the fabric becomes thicker, and the transport amount increases. There is a problem that. When the carry amount increases with respect to the reference value, there is a possibility that a positional deviation occurs in the carrying direction with respect to a position where the head originally moves, thereby causing a deviation in the image.
[0008]
For such a problem, there is also an idea of changing the conveyance amount according to the thickness of the cloth. However, the above-described transport variation is caused not only by the thickness of the cloth but also by various factors such as the thickness of the fiber and the smoothness of the surface, so that the transport amount is optimal based only on the thickness of the cloth. It cannot be. Therefore, each time the fabric to be printed is changed, the amount of conveyance is determined by trial and error, and the printed fabric image is observed with a microscope to determine whether there is any displacement in the printing. It took too much time to prepare.
[0009]
On the other hand, unlike paper, cloth has a property of being stretchable, so even when it is sandwiched between a pair of transport rollers and transported, depending on the transport mode, wrinkles and sagging may occur and image quality may be degraded. is there. Therefore, it is preferable if the cloth can be conveyed without causing wrinkles or sagging.
[0010]
Furthermore, since one fabric is usually about 50 m long, it takes more than 20 hours to print all of the fabric, so it is convenient that the inkjet printing apparatus can be operated automatically. is there. However, in order to enable the automatic operation, it is necessary to automatically stop the ink jet printing apparatus by detecting that the cloth to be printed is finished even when the worker is not nearby.
[0011]
SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems of the prior art, and an object of the present invention is to provide a printing cloth conveyance technique that is suitable for automatic operation and can appropriately print an image even when the cloth type is different.
[0012]
[Means for Solving the Problems]
The above object of the present invention is achieved by the following configurations.
1. A transport device for intermittently transporting the cloth to be printed;
Means for forming a predetermined pattern on the cloth by ejecting ink while the cloth conveyance is stopped while changing the intermittent conveyance amount of the conveying apparatus;
An ink jet printing apparatus characterized by comprising:
2. 2. The ink jet printing apparatus according to 1 above, further comprising a memory that stores a cloth type and a conveyance amount corresponding to the cloth type in association with each other.
3. 3. The ink jet printing apparatus according to 2 above, further comprising control means for controlling the conveying device so as to intermittently convey the cloth to be printed by a conveying amount corresponding to the selected cloth type.
4). A process of intermittently transporting the cloth to be printed;
A step of ejecting ink to a cloth based on a predetermined pattern while changing an intermittent conveyance amount;
A method for determining a transport amount of a printed fabric, comprising:
5. 5. The method for determining a printed fabric conveyance amount according to 4, wherein the pattern includes a pattern for ejecting ink with dots of maximum density.
6). 6. The method for determining a printed fabric conveyance amount according to 4 or 5, wherein the pattern includes a pattern in which a predetermined number of dots are thinned out in the conveyance direction with respect to a maximum density dot and the ink is emitted.
7). 7. The method for determining a printed fabric conveyance amount according to any one of 4 to 6, wherein the pattern includes a pattern for ejecting ink so that dots are arranged obliquely in the conveyance direction.
[0020]
[Action]
According to the ink jet printing apparatus of the present invention, the inkjet printing apparatus includes a transport device that transports a cloth to be printed, and an output device that emits ink to the cloth transported by the transport device. Since the conveyance amount is adjusted according to the type of cloth, for example, even when the cloth to be printed is different, an image can be printed appropriately.
[0021]
Furthermore, if the conveying device stops conveying the cloth while the emitting device emits ink to the cloth, it is possible to prevent image misalignment as much as possible.
According to the method for determining a textile transfer amount according to the present invention, the process of ejecting ink in a predetermined pattern while comparing the carry amount of the cloth and comparing the emitted pattern for each carry amount is optimal. And the step of determining a proper carry amount, the carry amount is adjusted according to the type of cloth to be printed. For example, even when the cloth to be printed is different, an image can be printed properly.
[0022]
In addition, it is desirable that the pattern includes a pattern in which ink is emitted with dots having the maximum density.
[0023]
Furthermore, it is desirable that the pattern includes a pattern in which a predetermined number of dots are thinned out in the transport direction with respect to the dots having the maximum density and the ink is emitted.
[0024]
Furthermore, it is desirable that the pattern includes a pattern for ejecting ink so that dots are arranged obliquely in the transport direction.
[0025]
According to the textile printing apparatus of the present invention, there are provided a transportation device that transports a cloth to be printed, and an output device that emits ink to the fabric to be transported in a predetermined pattern according to the selection of the transport amount adjustment mode. Since the optimum transport amount is determined by comparing the emitted pattern for each transport amount, for example, even when the cloth to be printed is different, an image can be printed appropriately.
[0026]
In addition, it is desirable that the pattern includes a pattern in which ink is emitted with dots having the maximum density.
[0027]
Furthermore, it is desirable that the pattern includes a pattern in which a predetermined number of dots are thinned out in the transport direction with respect to the dots having the maximum density and the ink is emitted.
[0028]
Furthermore, it is desirable that the pattern includes a pattern for ejecting ink so that dots are arranged obliquely in the transport direction.
[0029]
Further, when the transport device performs intermittent transport to stop the transport of the cloth while the emitting device emits ink to the cloth, the intermittent transport is performed at a pitch of 3 to 5 μm. By doing so, the carry amount can be adjusted accurately.
[0030]
Further, a storage means for storing information relating to the determined carry amount and information relating to the cloth type having the optimum carry amount is provided so that the carry device selects a cloth type to be printed. If the carry amount is determined based on the information called from the storage means, for example, for a previously printed fabric, the stored carry amount is used to properly print an image. Can do.
[0031]
According to the textile printing apparatus of the present invention, the textile printing apparatus includes a conveyance device that conveys the cloth to be printed, and an emission device that emits ink to the cloth conveyed by the conveyance device, and the conveyance device has at least an outer peripheral surface with rubber. Between the first and second rollers rotating, the first roller having a first member disposed thereon and the second roller having a sponge member disposed at least on the outer peripheral surface thereof, facing the first roller. Since the fabric is conveyed while being held between the two, for example, the fabric can be conveyed more smoothly than when the fabric is conveyed using a pair of rubber rollers.
[0032]
According to the textile printing apparatus of the present invention, a transport device that transports the cloth to be printed, an ejection device that ejects ink onto the fabric transported by the transport device, and a holding device that holds the transported fabric in the ejection position. The holding device includes a holding surface and suction means for bringing the cloth into close contact with the holding surface, so that ink is emitted while suppressing wrinkles and sagging as much as possible from the cloth to be printed. It is possible to appropriately hold at the emission position.
According to the textile printing apparatus of the present invention, the textile printing apparatus includes a conveyance device that conveys the cloth to be printed, and an emission device that emits ink to the cloth conveyed by the conveyance device. A pulling device that pulls out the cloth, and a pulling device that pulls the cloth that has passed through the emitting position, and the pulling device has a roller having at least fine irregularities on the outer surface, so that an appropriate tension is applied. The cloth can be applied to the cloth, whereby the cloth can be conveyed while suppressing wrinkles and sagging as much as possible.
[0033]
According to the textile printing apparatus of the present invention, the textile printing apparatus includes a conveyance device that conveys the cloth to be printed, and an emission device that emits ink to the cloth conveyed by the conveyance device. A feeding roller that feeds out and a pulling roller that pulls the cloth that has passed through the emission position, and the peripheral speed of the pulling roller is faster than the peripheral speed of the sending roller, so that an appropriate tension can be applied to the cloth. Thus, the cloth can be conveyed while suppressing wrinkles and sagging as much as possible.
[0034]
The peripheral speed of the pulling roller is preferably 3 to 7% (preferably 5%) faster than the peripheral speed of the feed roller.
[0035]
Furthermore, if the outer peripheral surface of the pulling roller is formed with minute projections for hooking the fibers of the cloth to be conveyed, tension can be applied to the cloth more effectively.
[0036]
According to the textile printing apparatus of the present invention, a transport device that transports a cloth to be printed, an output device that emits ink to the cloth transported by the transport device, and a detection that detects an end in the transport direction of the cloth to be printed. And when the detection device detects the conveyance direction end of the cloth to be conveyed, the conveyance device stops the conveyance of the fabric. Automatically stops, allowing automatic operation.
[0037]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described with reference to embodiments. First, when printing on a cloth, the cloth is pretreated, the image is printed by an ink jet method, the fixing (coloring) process is performed, and the excess ink is removed by a washing process. It becomes.
[0038]
FIG. 1 is a diagram illustrating a textile printing apparatus that performs printing by emitting ink to a pretreated cloth. FIG. 2 is a view of a head having a nozzle for emitting ink as viewed from above.
[0039]
In FIG. 1, a cloth CL is supported around the support shaft 1 while being wound around the support shaft 1. One end of the cloth CL is drawn upward, passes through the vicinity of the optical detection device 9, enters between the rubber roller 2 and the sponge roller 3, and is further disposed below the head 7 which is an ink ejection device. It passes over the holding table 4, wraps around the pulling roller 8, and goes downward from there. The rubber roller 2, the sponge roller 3, and the pulling roller 8 constitute a conveying device.
[0040]
The control device 10 can control the head 7, the stepping motor that drives the rubber roller 2 and the sponge roller 3, and the motor that drives the pulling roller 8 in an associated manner. Specifically, under the control of the control device 10, the rubber roller 2 and the sponge roller 3 are accurately rotated every predetermined minute angle by a stepping motor (not shown). The pulling roller 8 is also rotated at a predetermined speed by a motor (not shown). Further, the rubber roller 2 and the sponge roller 3 stop after rotating by a minute rotation angle, and the so-called intermittent rotation in which the head 7 moves while ejecting ink in a direction orthogonal to the cloth conveying direction and then slightly rotates again. Move.
[0041]
A large number of holes 4 a are formed so as to penetrate the upper surface of the holding table 4. A vacuum motor 6 as a suction means is provided below the holding table 4. By sucking air in the vacuum duct 5 that closes the space between the holding table 4 and the vacuum motor 6, The atmospheric pressure can be lowered.
[0042]
On the lower surface of the head 7, 64 nozzles 7 a, which are connected to a tank (not shown), are arranged for each color of ink, and can emit ink downward. In FIG. 2, only one row of nozzles 7a is arranged for easy understanding. The interval in the cloth conveyance direction between adjacent nozzles 7a is 420 μm.
[0043]
By the way, when the cloth is conveyed along the outer surface of the rubber roller projecting on a part of the flat surface, there is no problem of conveyance deviation. However, such a configuration requires a long surface in the transport direction, which increases the size of the apparatus. Therefore, in the present embodiment, the cloth CL is wound around the rubber roller 2 so as to be conveyed, thereby reducing the size of the apparatus.
[0044]
However, since the thickness varies depending on the type of cloth, the outermost diameter of the cloth CL at the time of winding around the rubber roller 2 varies depending on the thickness. Therefore, even if the rotation angle of the stepping motor is precisely controlled, the transport amount varies depending on the thickness of the cloth. On the other hand, the carry amount may vary depending not only on the thickness of the cloth but also on the material and surface treatment of the cloth. Therefore, in the present embodiment, the conveyance amount is adjusted as follows.
[0045]
First, as shown in FIG. 3, ink is ejected in a predetermined pattern onto a cloth to be printed. As an example, all the nozzles in one row are emitted to form one row of dots, for example. Next, the stepping motor is driven to rotate the rubber roller 2 by a rotation angle at which the cloth will move by 70 μm.
[0046]
Since the nozzles 7a are arranged at intervals of 420 μm in the cloth conveyance direction, when the emission of the nozzles 7a and the rotational movement of the rubber roller 2 are repeated six times, as long as the conveyance amount is correct to 70 μm, the seventh emission is essentially performed. The point should overlap with the first exit point of the preceding nozzle 7a (see FIG. 3A).
[0047]
However, since the thickness of the cloth to be conveyed is different, in practice, the conveyance amount is often larger or smaller than 70 μm. For example, when the actual transport amount is smaller than 70 μm, a gap larger than the interval between other points occurs between the sixth emission point A and the first emission point B of the preceding nozzle (see FIG. 3 (b)). Since each point is fine, this gap is visible as white streaks on the pattern.
[0048]
On the other hand, when the actual transport amount is larger than 70 μm, a gap smaller than the interval between other points occurs between the sixth emission point A and the first emission point B of the preceding nozzle. Depending on the case, a part of the polymerized polymer. In this case, the partially polymerized portion can be visually confirmed as a thick streak, and between other points can be confirmed as a thin white streak. Using such characteristics, the carry amount can be finely adjusted. The carry amount is not 70 μm, but may be (420 + 70) = 490 μm.
[0049]
Furthermore, when the pattern is formed so that the nozzles emit all points (at the maximum density), bleeding may occur depending on the type of cloth, and the white streaks as described above may not be visible. Therefore, in consideration of such a case, in the present embodiment, the following pattern is simultaneously formed on the cloth.
[0050]
Pattern (1): Ink is ejected at the maximum density pattern (2): Ink is ejected at 210 μm intervals (thinning out two dots)
Pattern (3): Ink is ejected at intervals of 420 μm (thinning out 5 dots)
Pattern (4): Ink is ejected at 840 μm intervals (thinning out 11 dots)
Pattern {circle around (5)}: It is preferable that there are at least three types of patterns for ejecting ink so that dots are arranged obliquely.
[0051]
FIG. 4 is a diagram showing a pattern in which ink is emitted so that dots are arranged obliquely. Such a pattern can be obtained, for example, by performing emission control so that only the nozzle adjacent to the right of the nozzle emitted by thinning out dots is emitted for every one pitch of conveyance.
[0052]
Since the nozzles 7a are arranged at intervals of 420 μm in the cloth conveyance direction, when the emission of the nozzles 7a and the rotational movement of the rubber roller 2 are repeated six times, the dots should be in a straight line as long as the conveyance amount is correct to 70 μm. (See FIG. 4 (a)).
[0053]
However, since the thickness of the cloth to be conveyed is different, the actual conveyance amount is often larger or smaller than 70 μm, so that the dots are not in a straight line and a discontinuous portion C is generated (FIG. 4 ( b)). Due to such characteristics, it is possible to detect a conveyance shift.
[0054]
FIG. 5 is a diagram schematically showing a state in which the above five patterns are simultaneously formed on the cloth while changing the rotation angle of the stepping motor by a minute amount. One pulse of the stepping motor is a value corresponding to about 4 μm in terms of the cloth conveyance amount. If the transport amount is 5 μm or less, it is generally considered impossible to discriminate with the human eye. Therefore, the minimum adjustment amount is preferably about 3 to 5 μm.
[0055]
According to the pattern of FIG. 5, when transported with 903 pulses, there are many thick streaks in the upper part, and when transported with 904 pulses, there are a few thick streaks in the upper part, and transported with 905 pulses. It was found that there were very few white streaks, and very thin streaks were present overall when transported with 906 pulses, and thin white streaks were generally present when transported with 907 pulses. In such a case, it can be seen that the optimum value of the carry amount is 905 pulses.
[0056]
FIG. 6 is a flowchart showing the transport amount adjusting method according to the present embodiment. When the conveyance amount adjustment mode of the printing apparatus is set, first, after setting a cloth desired to be printed in the printing apparatus, it is determined in step S101 in FIG. 6 whether or not the set cloth is a specified cloth. If the cloth is a prescribed cloth, the optimum value is already known, so the corresponding cloth type is selected in step S106. In such a case, the printing apparatus side reads the conveyance amount data stored in the memory (storage means) of the control device 10 corresponding to the selected fabric type, and automatically starts printing with the conveyance amount (step). S107).
[0057]
On the other hand, in step S101, if the set cloth is not a prescribed cloth, it is determined in step S102 whether or not it is the first cloth. If it is not the first cloth, the optimum value is already known. In step S106, the corresponding cloth type is selected. In such a case, the printing apparatus side reads the stored conveyance amount data corresponding to the selected cloth type, and automatically starts printing with the conveyance amount (step S107).
[0058]
If it is determined in step S102 that the cloth is the first, the optimum value of the carry amount cannot be determined. Therefore, the optimum carry amount is obtained in the following steps. That is, in step S103, the set cloth type name is stored in the textile printing apparatus, and in step S104, the carry amount is obtained. Specifically, as shown in FIG. 5, the carry amount is changed little by little, the pattern is emitted onto the cloth, and the most optimum carry amount is visually determined. Thereafter, in step S105, the optimum transport amount is stored in the memory of the control means 10 in association with the cloth type. After that, when printing an image on the same fabric type, the optimal transport amount is stored, so by selecting the fabric type name, the stepping motor automatically sets the optimal transport amount. To be controlled.
[0059]
The operation of the textile printing apparatus according to this embodiment will be described. In FIG. 1, the cloth CL is sandwiched between the rotating rubber roller 2 and the sponge roller 3 and is drawn out on the holding table 4, so that the cloth CL is slack and slack as compared with a case where the cloth CL is sandwiched between a pair of rubber rollers. It can be transported with as little deterrent as possible.
[0060]
On the other hand, the cloth CL fed out on the holding table 4 is adsorbed by the vacuum pump 6 and applied with a suction pressure of 11 to 14 kgf / cm ² , for example, by the negative hole 4a, and the holding surface below the head 7 is sucked. Since it can be held down to the top, it prevents wrinkles and sagging, thereby preventing image disturbance during ink ejection.
[0061]
Furthermore, the outer peripheral surface of the pulling roller 8 has a mat shape, and for example, minute protrusions are formed like rough sandpaper. Further, the peripheral speed of the pulling roller 8 is set to rotate 3 to 7% (preferably 5%) faster than the peripheral speed of the rubber roller 2. Under the control of the control device 10, the rubber roller 2, the sponge roller 3 and the pulling roller 8 are stopped (intermittent operation) for every predetermined minute conveyance amount, and the carriage 7 emits ink from the nozzles of the head 7a in the meantime. While moving in the lateral direction of the cloth, an image is formed.
[0062]
According to the present embodiment, the pulling roller 8 rotates quickly with respect to the rubber roller 2 to apply tension to the cloth, thereby preventing wrinkles and sagging. In such a case, the minute protrusions on the outer peripheral surface of the pulling roller 8 apply tension to the cloth so as to hook the fibers of the cloth. Since it is caught, it does not damage the cloth. Accordingly, the pulling roller 8 functions to apply tension while gently rubbing the surface of the cloth.
[0063]
Furthermore, at the stage where printing is completed to the vicinity of the end of the cloth CL, the optical detection device 9 detects a black tape portion that is normally provided at the end of the cloth CL. More specifically, the optical detection device 9 includes a light projecting unit that emits detection light and a light receiving unit that receives the detection light reflected from the cloth CL, and transmits a detection signal to the control device 10. It is possible.
[0064]
The reflectance differs between the material surface of the cloth CL and the black tape portion at the end. On the other hand, the reflectance is obtained by comparing the detected light amount and the reflected light amount. Therefore, if the reflectance is continuously measured, the optical detection device 9 can detect that the cloth CL has reached the end when the reflectance changes greatly. Thereby, since the control apparatus 10 can stop the rubber roller 2 etc. and can perform a required treatment, the textile printing apparatus can be automatically operated.
[0065]
【The invention's effect】
According to the present invention, there is provided a textile printing technique that can appropriately adjust different transport amounts for each type of cloth, can suppress wrinkles and sagging as much as possible, print a high-quality image, and enable automatic operation.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating a textile printing apparatus that performs printing by emitting ink to a pretreated cloth.
FIG. 2 is a view of a head provided with a nozzle for emitting ink as viewed from above.
FIG. 3 is a diagram illustrating a pattern of ink emitted to a cloth.
FIG. 4 is a diagram illustrating a pattern in which ink is emitted so that dots are arranged obliquely.
FIG. 5 is a diagram showing a state in which the five patterns are formed on the cloth at the same time while changing the rotation angle of the stepping motor by a minute amount.
FIG. 6 is a flowchart showing a transport amount adjusting method according to the present embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Support shaft 2 Rubber roller 3 Sponge roller 4 Holding stand 6 Vacuum pump 7 Head 8 Pulling roller

Claims (7)

A transport device for intermittently transporting the cloth to be printed;
Means for forming a predetermined pattern on the cloth by ejecting ink while the cloth conveyance is stopped while changing the intermittent conveyance amount of the conveying apparatus;
Inkjet printing apparatus characterized by have a. 2. The ink jet printing apparatus according to claim 1, further comprising a memory that stores the cloth type and the conveyance amount corresponding to the cloth type in association with each other . 3. The ink jet printing apparatus according to claim 2, further comprising control means for controlling the conveying device so as to intermittently convey the cloth to be printed with a conveying amount corresponding to the selected cloth type. . A process of intermittently transporting the cloth to be printed;
A step of ejecting ink to a cloth based on a predetermined pattern while changing an intermittent conveyance amount;
Marking Supplying dyed cloth conveying amount determining how to, comprising a. The method of claim 4, wherein the pattern includes a pattern that ejects ink with dots of maximum density. 6. The method for determining a printed fabric conveyance amount according to claim 4 , wherein the pattern includes a pattern in which a predetermined number of dots are thinned out in the conveyance direction with respect to the maximum density of dots and the ink is emitted . 7. The method for determining a transport amount of a printed fabric according to claim 4, wherein the pattern includes a pattern for ejecting ink so that dots are arranged obliquely in the transport direction .

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