JP2008265206A - Ink jetting device and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ink jetting device capable of accurately judging whether or not ink impact positions are good by using a simpler and less costly structure and having a highly productivity, and an ink jetting method. <P>SOLUTION: The ink jetting device 10 includes an ink jetting means 1 to jet ink onto a medium 7 through a nozzle. The ink jetting means 1 jets the ink to form a pattern on the medium 7 onto the medium 7, when there is a first clearance between the medium 7 and the nozzle and jets the ink to confirm the impact position of the ink on the medium 7 onto the medium 7 when there is a second clearance wider than the first clearance between the medium 7 and the nozzle. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an ink ejecting apparatus that ejects ink onto a medium using an ink ejecting unit, and more specifically, to eject a desired pattern on the medium by ejecting ink onto the medium using an inkjet head. The present invention relates to an ink ejecting apparatus that forms

  An ink ejecting apparatus equipped with an ink jet head is an apparatus that produces a printed matter on which a desired pattern is formed by ejecting a liquid such as ink onto a recording medium such as paper. The ink ejecting apparatus ejects ink onto a recording medium from an ejection port (nozzle) formed in an inkjet head.

  In the ink ejecting apparatus, there may occur a defect (a unique portion having deformation or damage of the nozzle due to deterioration over time and adhesion of dried ink to the nozzle) in the vicinity of the nozzle. Under the influence of the above problems, ink may not be ejected straight from the nozzle. That is, the ejected ink may land on a position shifted from a desired position on the recording medium.

  For this reason, in order to maintain a high pattern formation accuracy in the ink ejecting apparatus, it is necessary to maintain the ink landing accuracy. In order to maintain the ink landing accuracy, the ink ejecting apparatus usually inspects the landing position on the recording medium of the ink ejected from the nozzles regularly or irregularly. As a result of the inspection, when the ink is not ejected to the target position on the recording medium (not landed), maintenance of the ink ejecting apparatus (cleaning of the nozzles of the inkjet head, replacement of the inkjet head, etc.) is performed.

  As a method for inspecting the landing position of ink, a test ink is ejected onto a recording medium, and the position of the ink that has landed on the recording medium can be regarded as a range in which the nozzles are ejecting ink normally ( There is a method for determining whether or not it is in a normal landing area. As a method for the determination, there is a method for determining whether the ink landing position is good or not by visually comparing a sheet (inspection pass / fail pattern) on which a normal landing area is written with the ink position on the recording medium. is there.

  In addition to the visual determination method, Patent Document 1 proposes a method for performing the determination mechanically. The method described in Patent Document 1 is a method for determining whether the ink landing position is good or not on image data obtained by imaging ink landed on a recording medium with a camera. The above method is a method for detecting an ink landing position based on the image data and automatically determining whether or not the landing position is within a normal landing area by using an image processing apparatus.

Here, in recent years, an ink ejecting apparatus equipped with an inkjet head is used for printing a high-quality photograph and producing a member used for a display device (such as a color filter of a liquid crystal display device). The allowable range of the landing position deviation of the ink ejected by such an ink ejecting apparatus is about plus or minus several micrometers (μm). That is, the ink ejection device is required to have very high ink landing accuracy.
JP 2005-14216 A (published January 20, 2005)

  However, it is almost impossible to visually recognize a minute shift of only a few μm. That is, it can be said that it is impossible to determine the quality of the ink landing position by visual observation in an ink ejecting apparatus having very high ink landing accuracy.

  Further, when an image obtained by picking up the ink that has landed on the recording medium is visually observed, in order to accurately recognize the presence or absence of a slight deviation, the ink is landed while expanding each of the inks one by one. It is necessary to determine whether the position is good or bad. When determining the landing position of the ink while observing the image, it takes an enormous time to inspect the ink jet head having a large number of nozzles. As a result, the ratio of the time for performing ink ejection for forming a pattern in the entire processing time of the ink ejecting apparatus is shortened, leading to a decrease in productivity of the ink ejecting apparatus.

  Furthermore, since the enlarged image must be clear, the ink ejecting apparatus needs to include an imaging camera having a very high resolution. An imaging camera having a high resolution is naturally expensive. Therefore, the cost of the ink ejecting apparatus is increased.

  As described above, when the conventional method is used, an increase in cost cannot be avoided in order to accurately recognize a minute deviation of only a few μm and determine whether the ink landing position is good or bad. Therefore, there is a need for an ink ejecting apparatus that can accurately determine the quality of the ink landing position using a simpler and less expensive configuration and that has high productivity.

  The present invention has been made in view of the above problems, and an object of the present invention is to accurately determine the quality of an ink landing position using a simpler and cheaper configuration, and has high productivity. It is an object of the present invention to provide an ink ejecting apparatus and a method thereof.

In order to solve the above problems, the ink ejecting apparatus of the present invention
Comprising ink ejecting means for ejecting ink onto a medium via a nozzle;
The ink ejecting means is
When there is a first interval between the medium and the nozzle, the ink for forming a pattern on the medium is ejected onto the medium, and
When there is a second interval wider than the first interval between the medium and the nozzle, the ink for confirming the landing position of the ink on the medium is ejected onto the medium.

  Suppose that a certain nozzle has a defect (deformation and damage of the nozzle due to deterioration over time, adhesion of dried ink, etc.). The ink ejected from the defective nozzles flies in an oblique direction from the nozzles toward the medium. In other words, the trajectory of the ink flying is a straight line that forms an angle with a perpendicular drawn from the nozzle toward the medium (trajectory of ink ejected normally). Therefore, the landing position of the ink exists at a position shifted from the intersection (ink landing target) of the perpendicular and the medium.

  Here, when the nozzles, the landing positions of the ink, and the intersections of the perpendicular and the medium are connected, a right triangle having the three as vertices can be drawn. If the base of the right triangle is the line segment from the intersection point to the ink landing position, the side perpendicular to the base corresponds to the perpendicular drawn from the nozzle to the medium and is oblique to the base. Corresponds to the trajectory of the ink flying. The length of the base is proportional to the length of the side perpendicular to the base. That is, if the gap between the nozzle and the medium is increased, the degree of deviation of the ink landing position is increased (enlarged).

  However, in the conventional ink ejecting apparatus, when the ink for pattern formation is ejected and when the ink for confirming the ink landing position is ejected, the flying distance of the ink is the same in any case. In other words, the conventional ink ejecting apparatus has the same distance between the nozzle and the medium in ink ejection for pattern formation and ink landing position. For this reason, in the conventional ink ejecting apparatus, the quality determination of the ink landing position is based on an allowable range of misregistration (about several μm) required at the time of product manufacture (pattern formation).

  On the other hand, in the ink ejecting apparatus having the above configuration, the ink ejecting means ejects ink for forming a pattern on the medium onto the medium when there is a first interval between the medium and the nozzle. is there. The ink ejecting means ejects ink for confirming the landing position of the ink on the medium onto the medium when there is a second interval wider than the first interval between the medium and the nozzle. .

  Therefore, in the ink ejecting apparatus having the above configuration, when there is a first interval between the medium and the nozzle, the ink ejected from the nozzle having the defect is separated from the ink landing target on the medium by the distance A. In the case where the ink has landed at a position and there is a second interval between the medium and the nozzle, the ink ejected from the nozzle having the defect is a position separated from the ink landing target on the medium by a distance B longer than the distance A. To land on.

  That is, in the ink ejecting apparatus according to the present invention, when the landing position on the medium is confirmed for the ink ejected from the same nozzle, the landing position of the ink is deviated as compared with the case where the pattern is formed on the medium. The degree increases. If the degree of deviation of the ink landing position increases, it becomes easy to accurately recognize the degree of deviation of the landing position.

  For example, it is possible to accurately recognize the degree of deviation of the landing position even if an imaging camera with a very low resolution is used. Further, for example, when determining whether the ink landing position is good or bad using an image obtained by imaging a medium on which ink has been ejected, it is not necessary to enlarge the ink image and determine it one by one. That is, it is not necessary to use an expensive configuration to determine whether the ink landing position is good or not, and it is not necessary to check the ink landing positions one by one. As a result, it is possible to shorten the processing time for determining the quality of the ink landing position using a simple and inexpensive apparatus.

  Therefore, it is possible to accurately determine the quality of the ink landing position using a simple and inexpensive configuration, and to provide an ink ejecting apparatus with high productivity.

In the ink ejecting apparatus of the present invention,
Drive means for driving the ink ejecting means or the support for supporting the medium in a direction perpendicular to the surface of the medium facing the nozzle;
The driving means is
The ink ejecting means or the support base may be driven so that the first interval or the second interval is provided between the medium and the nozzle.

  In the above configuration, when the ink ejecting means or the support base is driven so that the driving means leaves the first gap between the medium and the nozzle, the ink ejecting means forms a pattern on the medium. Are ejected onto the medium. On the other hand, when the driving means drives the ink ejecting means or the support base so as to leave a second gap between the medium and the nozzle, the ink ejecting means The ink for confirming the ink landing position is ejected onto the medium.

  That is, in the ink ejecting apparatus having the above configuration, when confirming the landing position on the medium for the ink ejected from the same nozzle, the deviation of the landing position of the ink is smaller than when the pattern is formed on the medium. The degree increases. For this reason, it becomes easy to accurately recognize the degree of deviation of the landing position. That is, it is not necessary to use an expensive configuration to determine whether the ink landing positions are good or not, and it is possible to check the landing positions of a plurality of inks at a time.

  As a result, it is possible to shorten the processing time for determining the quality of the ink landing position using a simple and inexpensive apparatus. Therefore, the same effects as those of the ink ejecting apparatus described above can be obtained.

In the ink ejecting apparatus of the present invention,
A first support for supporting the medium for forming the pattern;
A second support for supporting the medium for confirming the landing position,
There is the first interval between the medium placed on the first support and the nozzle,
There may be a second space between the medium placed on the second support base and the nozzle.

  In the above configuration, when the medium is placed on the first support base, there is a first interval between the medium and the nozzle, so that the ink ejecting means forms a pattern on the medium. Are ejected onto the medium. On the other hand, when the medium is placed on the second support base, there is a second gap between the medium and the nozzle, so that the ink ejecting means is adapted to land the ink on the medium. The ink for confirming the position is ejected onto the medium.

  That is, in the ink ejecting apparatus having the above configuration, when confirming the landing position on the medium for the ink ejected from the same nozzle, the deviation of the landing position of the ink is smaller than when the pattern is formed on the medium. The degree increases. For this reason, it becomes easy to accurately recognize the degree of deviation of the landing position. That is, it is not necessary to use an expensive configuration to determine whether the ink landing positions are good or not, and it is possible to check the landing positions of a plurality of inks at a time. As a result, it is possible to shorten the processing time for determining the quality of the ink landing position using a simple and inexpensive apparatus.

  Furthermore, in order to realize the ink ejecting apparatus having the above-described configuration, a second support base may be provided at a position farther from the nozzle than the first support base. That is, if a part of the conventional ink ejecting apparatus is slightly modified, the ink ejecting apparatus having the above-described configuration can be manufactured. The ink ejecting apparatus having the above configuration can be realized without making a new capital investment.

  Therefore, the cost required for capital investment can be further reduced.

In the ink ejecting apparatus of the present invention,
The medium for confirming the landing position of the ink may be thinner than the medium for forming the pattern.

  In the above configuration, when a medium for forming a pattern is used as a medium for ejecting ink, there is a first interval between the medium and the nozzle. Ink for forming a pattern is ejected onto the medium. On the other hand, when a medium for confirming the landing position, which is thinner than the medium for forming a pattern, is used as the medium for ejecting ink, a second interval is provided between the medium and the nozzle. Therefore, the ink ejecting means ejects the ink for confirming the landing position of the ink on the medium onto the medium.

  That is, in the ink ejecting apparatus having the above configuration, when confirming the landing position on the medium for the ink ejected from the same nozzle, the deviation of the landing position of the ink is smaller than when the pattern is formed on the medium. The degree increases. For this reason, it becomes easy to accurately recognize the degree of deviation of the landing position. That is, it is not necessary to use an expensive configuration to determine whether the ink landing positions are good or not, and it is possible to check the landing positions of a plurality of inks at a time. As a result, it is possible to shorten the processing time for determining the quality of the ink landing position.

  Furthermore, if a pattern forming medium and an ink landing position confirmation medium are prepared, the same effects as those of the ink ejecting apparatus can be obtained. That is, since the conventional ink ejecting apparatus can be used as it is, there is no need for cost, work time, and interruption of the manufacturing process associated with modification or introduction of a new apparatus. An increase in the size of the ink ejecting apparatus due to the addition of a new configuration can be avoided.

  Therefore, by a simpler method, significant cost reduction, avoidance of complicated work, and improvement in productivity can be realized.

The ink ejecting apparatus of the present invention is
You may further provide the imaging means which images the said ink for confirming the landing position which was ejected on the said medium.

  The imaging unit may be any device that can acquire information about the position of the ink ejected onto the medium. As an imaging means, an imaging camera etc. are mentioned, for example.

  By having the above configuration, the position information of the ink ejected on the medium can be acquired as an image.

The ink ejecting apparatus of the present invention is
It is preferable to further include display means for displaying an image picked up by the image pickup means.

  The display means may be any display means that can display an image based on information acquired by the imaging means. Examples of the display means include a monitor.

  By having the said structure, the image showing the landing position of the ink ejected on the medium acquired by the imaging means can be displayed on a display means. By observing the image visually, the landing position of the ink ejected on the medium can be confirmed. In other words, by visually observing the image, it can be determined whether or not the ink landing position is within a region that should be regarded as a normal landing position.

  Since it can be visually determined whether or not the ink has landed at a normal landing position, the configuration for confirming the ink landing position in the ink ejecting apparatus can be simplified. Therefore, the configuration of the ink ejecting apparatus can be further simplified.

The ink ejecting apparatus of the present invention is
It is preferable that image processing means for performing processing for specifying the landing position of the ink based on the image picked up by the image pickup means is further provided.

  For example, the image processing unit can specify whether or not the landing position of the ink ejected on the medium is within the region set as the normal landing position based on the image acquired by the imaging unit. , Process the image.

  The process includes, for example, adding information on a region set as a normal landing position to the image. In this case, the image is in a state where the landed ink and the graphic indicating the region are represented. For this reason, if the ink that has landed in the graphic indicating the region falls within the graphic, the ink landing position can be determined to be normal, and if a portion of the ink protrudes from the graphic, It can be determined that the ink landing position is abnormal.

  If the image subjected to the above processing is displayed on a monitor or the like, the operator can instantaneously determine whether the ink landing position is good or bad. That is, the processing time of the ink ejecting apparatus can be further shortened.

  Further, if the information regarding the region and the ink landing position shown in the image subjected to the above processing is determined by a computer or the like, the ink ejecting apparatus performs processing necessary for pattern formation and confirmation of the ink landing position. Do it automatically. Therefore, it is not necessary for the operator to determine whether the ink landing position is good or bad. That is, the operation of the ink ejecting apparatus can be simplified.

In the ink ejecting apparatus of the present invention,
It is preferable that the image is an image obtained by imaging a plurality of the inks that are ejected from the plurality of nozzles onto the medium and for confirming a landing position.

  By having the above configuration, for example, the display unit displays an image in which the landing positions of a plurality of inks are captured on one display screen. Therefore, the quality of the landing positions of a plurality of inks can be determined by viewing one display screen. In addition, for example, the determination unit can determine whether or not the landing positions of the plurality of inks are good based on the information on the landing positions of the plurality of inks in one process. Therefore, it is possible to shorten the time required for determining whether the ink landing position is good or bad.

In the ink ejecting apparatus of the present invention,
It is preferable that the apparatus further includes an ejection control unit that controls ejection of the ink from the ink ejection unit so that each of the plurality of inks is arranged at an equal interval.

  By having the above configuration, when all of the plurality of inks have landed normally, a set of the plurality of landed inks has a regular arrangement. The regular arrangement includes, for example, a single straight line, a plurality of straight lines, a grid pattern, a plurality of equilateral triangles, and a plurality of rhombuses.

  By having the above-described configuration, a larger number of landed ink images can be included in one image as compared with a case where a set of a plurality of landed inks has an irregular arrangement. That is, it is possible to determine whether or not a plurality of ink landing positions are acceptable in a single process.

  In addition, even when some of the landings of the plurality of inks deviate, a set of the plurality of landing inks has an approximately regular arrangement. For this reason, an image of ink that is not regularly arranged among a plurality of landed ink sets is conspicuous. Ink images that are not regularly arranged are ink images that have undergone misregistration, so that it is easy to identify ink images that have undergone misregistration. That is, it is easy to determine whether or not the landing positions of a plurality of inks are acceptable.

  As described above, it is possible to further reduce the time required for determining the quality of the ink landing position.

The ink ejecting apparatus of the present invention is
It is preferable that the ejection control unit determines the equal interval based on a size of a region to be regarded as a normal landing position of the ink and a size of the image.

  If the interval between two adjacent inks is too small, there will be inconvenience when judging whether the ink landing position is good, such as a part of the two inks overlapping each other. In order to prevent a part of the two inks from overlapping, the interval between the two adjacent inks may be set based on the normal landing position of the ink and the size of the area to be considered. .

  The size of the region that should be regarded as the normal landing position of the ink can be obtained from the size of the positional deviation that should be allowed when confirming the landing position of the ink and the size of the ink that has landed on the medium. . The size of the positional deviation to be allowed when confirming the ink landing position is the product of the size of the positional deviation to be allowed at the time of pattern formation and the ratio between the first interval and the second interval.

  Here, for example, it is assumed that the ink landed on the medium has a substantially circular shape. At this time, the region is a substantially circular shape having a radius that is the sum of the size of the positional deviation to be allowed when the ink landing position is confirmed and the radius of the ink. At this time, if the equal interval is made larger than the diameter of the region, the two inks do not overlap.

  In addition, if the interval between two adjacent inks is too large, the number of ink images included in one image decreases. For example, if it is desired to arrange 10 ink images in one rectangular image in a straight line, the above equal interval should be set to be shorter than the length of 1/10 the horizontal width of the image. That's fine.

  In summary, with the above-described configuration, a desired number of ink images can be included in one image without overlapping adjacent inks. Therefore, it is possible to determine the quality of the ink landing position more accurately and quickly.

In the ink ejecting apparatus of the present invention,
The image display area of the display means is provided with a mark for distinguishing between the normal landing position and the abnormal landing position and the abnormal landing position of the ink landing positions. It is preferable that arranged sheets are disposed.

  For example, the sheet made of a material that transmits part of light is superimposed on a monitor or the like displaying an image obtained by imaging the ink landing position. The sheet is provided with a mark for distinguishing between a normal landing area and an abnormal landing area. It is possible to instantaneously determine whether the ink image displayed on the display means is within a normal landing area or whether a part of the ink image protrudes into the abnormal landing area.

  Therefore, the quality of the ink landing position can be determined accurately and quickly using an inexpensive configuration.

In order to solve the above problems, the ink ejection method of the present invention is
Including an ink ejecting step of ejecting ink from the ink ejecting means onto the medium through a nozzle;
In the ink ejecting step, when the ink ejecting means has a first interval between the medium and the nozzle, the ink for forming a pattern on the medium is ejected onto the medium;
When there is a second interval wider than the first interval between the medium and the nozzle, the ink for confirming the landing position of the ink on the medium is ejected onto the medium.

  In the above method, the ink ejecting means ejects ink for forming a pattern on the medium onto the medium when there is a first interval between the medium and the nozzle. The ink ejecting means ejects ink for confirming the landing position of the ink on the medium onto the medium when there is a second interval wider than the first interval between the medium and the nozzle. .

  Therefore, as described above, when there is a first interval between the medium and the nozzle, the ink ejected from the nozzle having a defect lands on a position separated by a distance A from the ink landing target on the medium. When there is a second interval between the medium and the nozzle, the ink ejected from the nozzle having the defect is landed at a position separated from the landing target of the ink on the medium by the distance B. Here, the distance B is longer than the distance A.

  That is, in the ink ejecting apparatus according to the present invention, when the landing position on the medium is confirmed for the ink ejected from the same nozzle, the landing position of the ink is deviated as compared with the case of forming the pattern on the medium. The degree increases. If the degree of deviation of the ink landing position increases, it becomes easy to accurately recognize the degree of deviation of the landing position.

  Therefore, the same effects as those of the ink ejecting apparatus described above can be obtained.

  As described above, according to the present invention, it is between the nozzle and the medium that the ink for checking the landing position of the ink is ejected rather than the ink for ejecting the pattern. The interval becomes larger. For this reason, when ink for confirming the ink landing position is ejected, the degree of deviation of the ink ejected through the defective nozzle from the target landing position can be increased. Therefore, it is possible to accurately determine the quality of the ink landing position using a simple and inexpensive configuration, and to provide an ink ejecting apparatus with high productivity.

  Embodiments according to the present invention will be described with reference to FIGS. In the following description, the same members and components are denoted by the same reference numerals. The names and functions are also the same. Therefore, detailed description thereof will not be repeated.

(Embodiment 1)
The ink ejecting apparatus 10 according to the present embodiment will be described below with reference to FIGS. FIG. 1 is a plan view illustrating a configuration of a main part of the ink ejecting apparatus 10. FIG. 2 is a plan view showing the configuration of the inkjet head 1. FIG. 3A is a plan view showing a landing position of ink in a medium on which ink for pattern formation is ejected, and FIG. 3B is a plan view of ink in a medium on which ink ejection for confirming the landing position is performed. It is a top view which shows a landing position. FIG. 4 is a flowchart illustrating a processing procedure of the ink ejecting apparatus 10.

(Configuration of Ink Ejecting Device 10)
As shown in FIG. 1, the ink ejecting apparatus 10 includes an ink jet head 1 (ink ejecting means) in which a plurality of nozzles are formed, a camera 2 (imaging means) that images ink that has landed on a substrate 7 (medium), A printing table 3 (first support table) on which the substrate 7 is placed, a driving unit 6 (driving means) for driving the inkjet head 1 in the Y-axis direction, and driving the inkjet head 1 and the imaging camera 2 in the X-axis direction. And a guide 5 supported by the drive unit 4.

(Inkjet head 1)
The ink jet head 1 ejects ink onto the substrate 7 through nozzles. When the ink jet head 1 ejects ink onto the substrate 7, the ink ejecting apparatus 10 confirms the landing position of the printed matter (hereinafter simply referred to as “printed matter”) on which a desired pattern is formed. A printed material (hereinafter referred to as “printed material for confirmation”) is prepared.

  The printed matter is a product or a member constituting the product. The printed matter for confirmation is used to determine whether or not the nozzle state is normal based on the ink landing position.

(Nozzle 11)
As shown in FIG. 2, 24 nozzles 11 a to 11 x are formed in the inkjet head 1 in order from the left in the drawing. The nozzles 11a to 11x are arranged in a straight line, and constitute a nozzle 11 row. The nozzle 11 row is usually formed by molding or punching all at once. For this reason, the shape of the plurality of nozzles 11a to 11x constituting the nozzle 11 row has very high accuracy. Due to the very high accuracy of the shapes of the plurality of nozzles 11a to 11x, the degree of positional deviation can be kept within a very small range (for example, about 5 μm).

  However, the nozzle 11 cannot keep the degree of positional deviation within a minute range due to problems such as adhesion of dried ink around the nozzle 11 hole and deterioration of the nozzle 11 over time. That is, the above-described defective ink ejection occurs due to the adhesion of ink to the nozzle 11 or the aging of the nozzle 11.

  For this reason, it is necessary to inspect the defect of the nozzle 11 by producing a printed matter for confirmation regularly or irregularly.

(Camera 2 and display means)
The camera 2 is a structure for imaging the ink ejected on the printed matter for confirmation (acquiring image information). The image information of the ink ejected on the printed matter for confirmation obtained by the camera 2 is output to a display unit (display means) such as a monitor (not shown).

  When the image information is output to the display unit, the operator of the ink ejecting apparatus 10 confirms the landing position of the ink ejected on the printed matter for confirmation by observing the image displayed on the display unit. To do. That is, the operator determines the quality of the ink landing position based on the image displayed on the display unit.

  The operator determines that the landing position of a certain ink is defective when the landing position of a certain ink is deviated from the target landing position by a degree larger than the allowable positional deviation. The degree of positional deviation to be allowed is, for example, about 5 μm in the ink ejecting apparatus 10 for producing a color filter that has been put into practical use. Usually, the ink ejecting apparatus 10 allows only a very small positional deviation.

  When the operator determines that the ink landing position is defective, the operator determines that there is a defective nozzle 11 and instructs maintenance of the inkjet head 1 to the ink ejecting apparatus 10. Maintenance of the inkjet head 1 includes cleaning of the nozzle 11 and replacement of the inkjet head 1.

(Driver 4)
The drive unit 4 drives the inkjet head 1 and the camera 2 along the guide 5 in the X-axis direction. That is, the drive unit 4 is configured to relatively move the substrate 7, the inkjet head 1, and the camera 2. By driving the inkjet head 1 using the drive unit 4, it is possible to eject ink to an arbitrary position in the X-axis direction of the substrate 7. By driving the camera 4 using the drive unit 4, it is possible to image an arbitrary position in the X-axis direction of the substrate 7.

  The ink ejecting apparatus 10 may further include another set of the drive unit 4 and the guide 5. The other set of drive unit 4 and guide 5 may be arranged so that the inkjet head 1 and the camera 2 can be driven in the Z-axis direction. As a result, the inkjet head 1 and the camera 2 can scan the entire surface of the opposite substrate 7. Further, the ink ejecting apparatus 10 may be configured to drive the printing table 3 by connecting the driving unit 4 and the guide 5 to the printing table 3.

(Driver 6)
The drive unit 6 drives the inkjet head 1 in the Y-axis direction. That is, the drive unit 6 changes the interval between the nozzle 11 and the printing material 7 placed on the printing table 3.

  When producing the printed matter, the drive unit 6 moves the inkjet head 1 so that the interval between the nozzle 11 formed on the inkjet head 1 and the printed material 7 placed on the printing table 3 is the interval W1. Drive. When producing the printed matter for confirmation, the driving unit 6 causes the interval between the nozzles 11 formed on the inkjet head 1 and the printed material 7 placed on the printing table 3 to be larger than the interval W1. The inkjet head 1 is driven.

  When the interval between the nozzle 11 and the printing material 7 is the interval W1, the inkjet head 1 performs ink ejection for producing the printed material. When the interval between the nozzle 11 and the printing material 7 is larger than the interval W1, the inkjet head 1 performs ink ejection for producing the printed material for confirmation. When the interval between the nozzle 11 and the substrate 7 is larger than the interval W1, the ink jet head 1 performs ink ejection for producing the printed matter for confirmation because the degree of deviation of the ink landing position is determined. This is to enlarge (enlarge).

  As described above, the ink ejected by the ink ejecting apparatus 10 normally allows only a very small positional deviation. For this reason, ink that has been displaced to an extent that should not be allowed (hereinafter referred to as “bad ink”) and ink that has been caused to be allowed to be shifted (hereinafter referred to as “normal ink”). Is difficult to distinguish.

  Normal ink is ink that is ejected from the nozzle 11 and then flies perpendicularly to the substrate 7 (parallel to the Y axis). On the other hand, the defective ink is ink that did not fly perpendicularly to the substrate 7 after being ejected from the nozzle 11 (flighted obliquely). For this reason, the landing position of the defective ink exists at a position shifted from the landing position of the normal ink.

  Here, a trajectory of normal ink flying, a trajectory of defective ink, and a line connecting the landing position of the defective ink and the landing position of the normal ink respectively constitute sides of a right triangle. The length of the trajectory of normal ink flying is equal to the length of the gap between the nozzle 11 and the substrate 7. Further, the length of the line connecting the landing position of the defective ink and the landing position of the normal ink is equal to the distance at which the defective ink is displaced. For this reason, the distance at which the defective ink is displaced is proportional to the length of the gap between the nozzle 11 and the substrate 7. That is, if the interval between the nozzle 11 and the printing material 7 is increased, the degree of displacement of the landing position of defective ink increases (enlarges).

  That is, for the ink ejected from the same nozzle 11, when the landing position of the ink in the printed matter for confirmation is confirmed, the degree of deviation of the landing position of the ink is greater than when the printed matter is produced. If the degree of deviation of the ink landing position increases, it becomes easy to accurately recognize the degree of deviation of the landing position.

  For this reason, for example, even if the camera 2 having a resolution that is not so high is used, it is possible to accurately recognize the degree of misalignment of the defective ink. Further, for example, when the quality of the ink landing position is determined using an image obtained by capturing a printed matter for confirmation, it is not necessary to enlarge the image and determine each ink. That is, it is not necessary to use an expensive configuration to determine whether the ink landing position is good or not, and it is not necessary to check the ink landing positions one by one. As a result, it is possible to shorten the processing time for determining the quality of the ink landing position using a simple and inexpensive apparatus.

  Since the drive unit 6 drives the inkjet head 1 so that the interval between the nozzle 11 and the substrate 7 during the production of the printed material for confirmation is larger than the interval W1 during the production of the printed material, Using an inexpensive configuration, it is possible to accurately determine whether the ink landing position is good or not, and to provide the ink ejecting apparatus 10 with high productivity.

  Note that the drive unit 6 drives the inkjet head 1 so that the interval W1 during the production of the printed material is about 0.3 mm to 1 mm due to the flatness of the surface of the printed material 7 or the like. The driving unit 6 also drives the inkjet head 1 so that the interval at the time of producing the printed matter for confirmation is larger than the interval W1, and the defective ink causes a displacement of a desired size. The drive unit 6 drives the inkjet head 1 before the inkjet head 1 ejects ink, and does not drive the inkjet head 1 when the inkjet head 1 is ejecting ink.

(Comparison of ink landing position deviation)
With reference to FIGS. 3A and 3B, the fact that the degree of deviation of the landing positions of the ink at the time of producing the printed matter for confirmation is greater than that at the time of producing the printed matter will be described below. FIG. 3A is a plan view showing the position of the ink 12 ejected onto the printing material 7 when there is a gap W1 between the nozzle 11 and the printing material 7, and FIG. FIG. 5 is a plan view showing the position of the ink 12 ejected on the substrate 7 when there is a gap wider than the interval W1 between the nozzle 11 and the substrate 7.

  As shown in FIG. 3A, normal ink 12 and defective ink 12 'are present on the substrate 7 to be printed. There is almost no deviation in the landing position between the normal ink 12 and the defective ink 12 '.

  As described above, if there is a defect in the nozzle 11 hole (such as adhesion of dried ink 12 or flash generated when the nozzle 11 hole is formed), the ejected ink 12 is pulled by the defect and ejected obliquely. . The smaller the distance between the nozzle 11 and the substrate 7, the smaller the displacement of the landing position of the ejected ink 12 on the substrate 7. Therefore, it is preferable that the deviation of the landing position of the ink 12 is made as small as possible when the printed material is produced. Usually, in an ink ejecting apparatus that has been put into practical use, by setting the distance between the nozzle 11 and the printing material 7 to about 0.3 mm to 1 mm, the deviation of the landing position is suppressed to about 5 μm.

  The malfunction of the nozzle 11 hole is caused by the adhesion of the ink 12 to the nozzle 11 hole or the aging of the nozzle 11 hole. For this reason, it is necessary to check not only when the ink jet head 1 is replaced, but also whether the landing position of the ink 12 has been shifted so much that it should not be allowed. However, it is not easy to identify whether the displacement of the landing position of the ink 12 is 5 μm or more.

  As shown in FIG. 3B, normal ink 12 and defective ink 12 ″ are present on the substrate 7. The normal ink 12 and the defective ink 12 ″ are inks ejected from the nozzle 11 when the gap between the nozzle 11 and the substrate 7 is wider than the gap W1. Therefore, the deviation of the landing position between the normal ink 12 and the defective ink 12 ″ is larger (enlarged) than the deviation of the landing position between the normal ink 12 and the defective ink 12 ′.

  As described above, since the difference in landing position between the normal ink 12 and the bad ink 12 ″ is enlarged, the normal ink 12 and the bad ink 12 are captured in the image obtained by imaging the printed matter for confirmation by the camera 2. '' Can be easily identified.

(Processing of Ink Ejecting Device 10)
Details of the ink ejection processing performed by the ink ejection device 10 will be described below with reference to FIG. FIG. 4 is a flowchart for explaining an example of a flow of processing in which the ink ejecting apparatus 10 produces a printed matter or a printed matter for confirmation and performs head maintenance.

  As shown in FIG. 4, the ink ejecting apparatus 10 determines whether or not ink ejection is performed for producing a printed material (step S <b> 1). Whether or not ink ejection is performed for the production of a printed matter may be determined by an instruction input by an operator, or may be determined by the ink ejection device 10. References for the operator or the ink ejecting apparatus 10 to determine whether or not ink ejection is performed for the production of a printed material include the presence / absence of replacement of the inkjet head 1 and the number of times the printed material is produced continuously.

  When the ink-jet head 1 is replaced, the nozzles 11a to 11x formed on the ink-jet head 1 may have a defect that occurs during molding. For this reason, if the ink jet for confirming the landing position of the ink 12 is performed after the ink jet head 1 is replaced, it is possible to confirm whether or not the ink jet head 1 is defective.

  Repeated ejection of the ink 12 causes adhesion of the dried ink 12 to the nozzle 11 hole, deformation of the nozzle 11 hole due to deterioration over time, and the like. For this reason, it is preferable to periodically check the landing position of the ink 12. Whether or not to check the landing position of the ink 12 may be determined based on the number of times the printed material is continuously produced. For example, if the number of times is 10 or less, ink ejection for producing a printed material is performed. For example, when the number of times exceeds 11, ink ejection for producing a printed matter for confirmation is performed. The number of times may be recognized by the operator, or the ink ejecting apparatus 10 may recognize it.

  A case will be described below where it is determined in step S1 that the ink 12 is ejected (Yes) in order to produce a printed material. If it is determined Yes in step S1, the drive unit 6 drives the inkjet head 1 so that the interval between the nozzle 11 and the substrate 7 becomes the interval W1 (step S2). Further, the drive unit 4 moves the inkjet head 1 to a desired ejection start position of the ink 12.

  The interval W <b> 1 may be such a size that the nozzle 11 does not come into contact with the unevenness on the surface of the printing material 7 and a size that allows the ejected ink 12 to normally land on the printing material 7. When the printed material 7 having the same specification is used to continuously produce the printed material, the driving of the inkjet head 1 by the driving unit 6 may not be performed.

  In order to produce a printed material (form a desired pattern on the printed material 7), the inkjet head 1 ejects the ink 12 through the nozzles 11a to 11x (step S3). For example, in order to form the desired pattern on the substrate 7, the number and timing of the ink 12 ejected by the plurality of nozzles 11 a to 11 x may be set in advance. When the ejection of the ink 12 by the inkjet head 1 is completed (a desired pattern is formed on the substrate 7), the ink ejection device 10 ends the process.

  Next, the case where it is determined in step S1 that the ink 12 is ejected (No) in order to produce a printed matter for confirmation instead of producing a printed matter will be described below. When it is determined No in step S1, the drive unit 6 drives the inkjet head 1 so that the interval between the nozzle 11 and the printing material 7 is wider than the interval W1 (step S4). Further, the drive unit 4 moves the inkjet head 1 to a desired ejection start position of the ink 12.

  In order to produce a printed matter for confirmation, the inkjet head 1 ejects the ink 12 through the nozzles 11a to 11x (step S5). As described above, in step S4, the interval between the nozzle 11 and the substrate 7 is adjusted to be wider than the interval W1. Therefore, the deviation of the landing position of the ink 12 is emphasized (enlarged) more than when the printed material is produced. In step S5, if the ink 12 is ejected so that the pattern in which the ink 12 is landed on the substrate 7 is constant, the subsequent step position of the ink 12 can be easily confirmed. The pattern for landing the ink 12 on the substrate 7 will be described later.

  The ink 12 landed on the substrate 7 is imaged by the camera 2 (step S6). The camera 2 may be moved above the ink 12 landed on the substrate 7 by the drive unit 4 before imaging the ink 12. Based on the image captured by the camera 2, the landing position of the ink 12 landed on the substrate 7 is confirmed (step S7). The landing position of the ink 12 is visually confirmed by the operator by displaying the image on the display means.

  Here, the image includes an image of the ink 12 in which the deviation of the landing position is emphasized (enlarged). For this reason, even when a low-resolution camera as the camera 2 is used, the landing position of the ink 12 can be easily and accurately confirmed. Further, it is not necessary to enlarge the image and check the images of the ink 12 one by one.

  It is determined whether or not the landing position of the ink 12 confirmed in step 7 falls within a deviation within a range that should be allowed from the target landing position (step S8). Based on the landing position of the ink 12 confirmed in step S7, the operator determines the quality of the landing position of the ink 12. In step S8, when it is determined that the ink 12 is within the allowable deviation from the target landing position and the ink landing position is normal (Yes), the ink ejecting apparatus 10 ends the process. .

  On the other hand, if it is determined in step S8 that there is an ink 12 that has caused a positional shift that should not be allowed from the target landing position (No), maintenance of the inkjet head 1 is performed (S9). Maintenance of the inkjet head 1 is, for example, replacement of the inkjet head 1 or cleaning of the nozzle 11 rows. When the maintenance of the inkjet head 1 is completed, the ink ejecting apparatus 10 ends the process.

  As described above, the ink ejecting apparatus 10 can produce a printed matter and a printed matter for confirmation. Furthermore, using the ink ejecting apparatus 10, it is possible to easily and accurately check and determine the landing position of the ink 12 that has landed on the printed matter for confirmation. Maintenance of the inkjet head 1 is performed based on the determination result.

  Therefore, since the ink ejecting apparatus 10 can always keep the ink jet head 1 in a normal state, a uniform printed matter can be produced. Furthermore, an inexpensive configuration can be adopted as a configuration for confirming and determining the landing position of the ink 12.

(Embodiment 2)
The ink ejecting apparatus 50 according to this embodiment will be described below with reference to FIGS. 5 and 6. FIG. 5 is a plan view showing the configuration of the main part of the ink ejecting apparatus 50. FIG. 6 is a flowchart illustrating a processing procedure of the ink ejecting apparatus 50.

(Configuration of Ink Ejecting Device 50)
As shown in FIG. 5, the ink ejecting apparatus 50 and the ink ejecting apparatus 10 are different in the configuration for adjusting the interval between the nozzle 11 and the substrate 7. Specifically, the ink ejecting apparatus 50 is provided with a printing stand 3 a having a height smaller than that of the printing stand 3 next to the printing stand 3 instead of being provided with the driving unit 6. Since there is no difference between the ink ejecting apparatus 50 and the ink ejecting apparatus 10 with respect to other configurations, description thereof is omitted here. See Embodiment 1 for the other configurations.

  As described above, the printing stand 3 a is lower than the printing stand 3. For this reason, there is a gap W <b> 1 between the printing object 7 placed on the printing table 3 and the nozzle 11. On the other hand, there is an interval W2 between the printing object 7 placed on the printing table 3a and the nozzle 11. The interval W2 is wider than the interval W1.

  The ink ejecting apparatus 50 moves the inkjet head 1 to above the printing table 3 or the printing table 3a by the driving unit 4 when the printed material is produced, and moves the inkjet head 1 by the driving unit 4 when the printed material for confirmation is produced. 3 or above the printing stand 3a. In other words, the ink ejecting apparatus 50 ejects the ink 12 onto the printing material 7 placed on the printing table 3 when the printed material is produced. On the other hand, the ink ejecting apparatus 50 ejects the ink 12 to the printing material 7 placed on the printing table 3a when the printed material for confirmation is produced.

  Therefore, if the ink ejecting apparatus 50 is used, the deviation of the landing position of the ink 12 ejected onto the printing material 7 is emphasized (enlarged) when the printed matter for confirmation is produced. That is, if the ink ejecting apparatus 50 is used, as in the ink ejecting apparatus 10, it is possible to recognize the displacement of the landing position of the ink 12 easily and accurately.

  In the present embodiment, the inkjet head 1 is moved by the drive unit 4, but a drive unit that moves the printing table 3 and the printing table 3a in the X-axis direction may be provided. In the present embodiment, the printing stand 3 and the printing stand 3a are configured by connecting different stands, but may be configured as one stand having a step.

(Processing of Ink Ejecting Device 50)
Details of the ink ejection processing performed by the ink ejection device 50 will be described below with reference to FIG. FIG. 6 is a flowchart for explaining an example of a process flow in which the ink ejecting apparatus 50 produces a printed matter or a printed matter for confirmation and performs head maintenance.

  Since the ink ejecting apparatus 50 has many common points with the ink ejecting apparatus 10, the processing is the same in most respects. As described above, the processing of the ink ejecting apparatus 50 is different from the processing of the ink ejecting apparatus 10 in the method of adjusting the interval between the nozzle 11 and the substrate 7. Therefore, only a method for adjusting the distance between the nozzle 11 and the substrate 7 by the ink ejecting apparatus 50 will be described.

  A case will be described below where it is determined in step S1 that the ink 12 is ejected (Yes) in order to produce a printed material. As shown in FIG. 6, when it is determined as Yes in step S1, the drive part 4 moves the inkjet head 1 above the to-be-printed material 7 mounted in the printing stand 3 (step S20). Further, the drive unit 4 moves the inkjet head 1 to a desired ejection start position of the ink 12. As a result, the interval between the nozzle 11 and the substrate 7 becomes the interval W1.

  In the state where the interval is the interval W1, the ink 12 is ejected (step S3). When a desired pattern is formed on the printing material 7 (production of the printed material is completed), the ink ejecting apparatus 50 ends the process.

  Next, the case where it is determined in step S1 that the ink 12 is ejected (No) for the production of a printed matter for confirmation will be described below. When it is determined No in step S1, the drive unit 4 moves the inkjet head 1 above the substrate 7 placed on the printing table 3a (step S40). Further, the drive unit 4 moves the inkjet head 1 to a desired ejection start position of the ink 12.

  As a result, the interval between the nozzle 11 and the substrate 7 becomes the interval W2. That is, the space between the nozzle 11 and the printing material 7 is wider than when the printed material is produced. For this reason, the deviation of the landing position of the ink 12 that has landed on the substrate 7 is emphasized (enlarged). Therefore, the landing position of the image of the ink 12 imaged in step S6 can be confirmed accurately and easily in step S7. That is, whether the landing position of the ink 12 in step S8 is good or not can be determined accurately and quickly.

  If it is determined Yes in step S8, the ink ejecting apparatus 50 ends the process. On the other hand, when it is determined No in step S8, the ink ejecting apparatus 50 performs the maintenance of the inkjet head 1 (step S9), and then ends the process.

(Embodiment 3)
An ink ejecting apparatus 70 according to this embodiment will be described below with reference to FIGS. 7 and 8. FIG. 7A is a plan view showing a configuration at the time of pattern formation of an ink ejecting apparatus which is another modification of FIG. 1, and FIG. 7B is an ink landing of the ink ejecting apparatus of FIG. It is a top view which shows the structure at the time of the confirmation of a position. FIG. 8 is a flowchart illustrating a processing procedure of the ink ejecting apparatus 70.

(Configuration of Ink Ejecting Device 70)
As shown in FIGS. 7A and 7B, the ink ejecting apparatus 70 includes an inkjet head 1 in which a plurality of nozzles are formed, a camera 2 that images ink that has landed on the printed materials 7 and 7 a, and the printed material 7. , 7a, a drive unit 4 for driving the inkjet head 1 and the imaging camera 2 in the X-axis direction, and a guide 5 supported by the drive unit 4.

  The difference between FIG. 7A and FIG. 7B is that the substrate to be ejected with ink 12 is different. That is, as shown in FIG. 7A, the printed material 7 used when producing the printed material has a thickness W3, and as shown in FIG. 7B, the printed material used when producing the printed material for confirmation. 7a has a thickness W4.

  For this reason, in the ink ejecting apparatus 70, when the printed material is produced, there is a gap W1 between the nozzle 11 and the printed material 7, and when the printed matter for confirmation is produced, there is a gap W2 between the nozzle 11 and the printed material 7a. is there. Therefore, the same effects as those of the ink ejecting apparatuses 10 and 50 according to the first and second embodiments are obtained.

  Further, the ink ejecting apparatus 70 does not require the drive unit 6 unlike the ink ejecting apparatus 10, and does not require the printing stand 3 a unlike the ink ejecting apparatus 50. That is, the configuration is more compact. In addition to this, since the printed material 7a can be prepared by preparing the printing material 7a, it is not necessary to modify the apparatus.

  For the configuration of the ink ejecting apparatus 70, the configurations of the ink ejecting apparatuses 10 and 50 may be referred to as appropriate, except that there are two types of printed materials 7 and 7a to be used. Refer to Embodiment Mode 1 for details of other structures.

(Processing of Ink Ejecting Device 70)
Details of the ink ejection processing performed by the ink ejection device 70 will be described below with reference to FIG. FIG. 8 is a flowchart for explaining an example of a flow of processing in which the ink ejecting apparatus 70 produces a printed matter or a printed matter for confirmation and performs head maintenance.

  Since the ink ejecting apparatus 70 has much in common with the ink ejecting apparatuses 10 and 50, the processing is the same in most respects. As described above, the processing of the ink ejecting apparatus 70 is different from the processing of the ink ejecting apparatuses 10 and 50 in the method of adjusting the interval between the nozzle 11 and the printing material. For this reason, only the method for adjusting the distance between the nozzle 11 and the printing material by the ink ejecting apparatus 70 will be described.

  A case will be described below where it is determined in step S1 that the ink 12 is ejected (Yes) in order to produce a printed material. As shown in FIG. 8, when it is determined as Yes in step S1, the to-be-printed material 7 is mounted in the printing stand 3 (step S21). Further, the drive unit 4 moves the inkjet head 1 to a desired ejection start position of the ink 12. As a result, the interval between the nozzle 11 and the substrate 7 becomes the interval W1.

  In the state where the interval is the interval W1, the ink 12 is ejected (step S3). When a desired pattern is formed on the printing material 7 (production of the printed material is completed), the ink ejecting apparatus 70 ends the process.

  Next, the case where it is determined in step S1 that the ink 12 is ejected (No) for the production of a printed matter for confirmation will be described below. When it is determined No in step S1, the substrate 7a is placed on the printing table 3 (step S41). Further, the drive unit 4 moves the inkjet head 1 to a desired ejection start position of the ink 12.

  As a result, the interval between the nozzle 11 and the substrate 7a becomes the interval W2. That is, the space between the nozzle 11 and the printing material 7 is wider than when the printed material is produced. For this reason, the deviation of the landing position of the ink 12 that has landed on the substrate 7 is emphasized (enlarged). Therefore, the landing position of the image of the ink 12 imaged in step S6 can be confirmed accurately and easily in step S7. That is, whether the landing position of the ink 12 in step S8 is good or not can be determined accurately and quickly.

  When it is determined Yes in step S8, the ink ejecting apparatus 70 ends the process. On the other hand, when it is determined No in step S8, the ink ejecting apparatus 70 performs maintenance of the inkjet head 1 (step S9), and then ends the process.

(Confirmation of landing position of ink 12 and determination of pass / fail)
A method for confirming the landing position of the ink 12 and determining whether it is acceptable will be described below with reference to FIG. FIG. 9A is a plan view showing an image of a medium ejected with ink displayed on the monitor, and FIG. 9B is a plan view showing a sheet for determining whether the landing position is good or bad. 9C is a plan view showing a state in which the sheet of FIG. 9B is superimposed on the image of FIG. The confirmation and pass / fail judgment methods described here are only specific examples, and other conventionally known methods may be referred to and added or changed as necessary.

  As illustrated in FIG. 9A, an image 100 obtained by capturing a printout for confirmation displayed on the display unit includes images of inks 12 and 12 ″. The dashed line in the figure is the target landing position in the vertical direction. The landing positions of the inks 12 and 12 ″ are confirmed by superimposing a transparent sheet 101 having the same size as the image 100 on the image 100.

  As shown in FIG. 9B, the transparent sheet 101 is provided with a mark for distinguishing between a normal landing position and a region 102 to be regarded as a normal landing position and a defective landing position and a region 103 to be regarded as a defective landing position. ing. For example, the region 102 of the transparent sheet 101 is not colored at all. On the other hand, the region 103 of the transparent sheet 101 is colored with a different color from the inks 12 and 12 ″. The transparent sheet 101 includes a region 102 that is not colored by the number of inks 12 and 12 ″ included in the image 100. The shape and size of the region 102 are calculated from the allowable amount of deviation during the production of the printed material and the ratio between the interval W1 and the interval W2.

  As shown in FIG. 9C, an image 104 obtained by superimposing a sheet 101 on an image 100 includes a plurality of uncolored regions 102 surrounded by a colored region 103. In the region 102, ink 12 and A 12 ″ image is transmitted. By observing the image 104, it can be seen that the ink 12 is within the region 102 to be regarded as a normal landing position. On the other hand, a part of the ink 12 ″ protrudes into the colored region 103. That is, the ink 12 is ink that has landed normally, and the ink 12 ″ is defective ink that has been displaced beyond the allowable range.

  As described above, by superimposing the sheet 101 on the image 100, the positions of the images of the inks 12 and 12 ″ in the image 100 can be instantaneously confirmed and the quality of the landing position can be determined. That is, it is possible to quickly and accurately check the landing positions of the inks 12 and 12 ″ and determine whether they are good or bad by a simple operation of superimposing the sheet 101 on the image 100. In other words, it is possible to quickly and accurately find the nozzle 11 in which a problem has occurred.

  When a defective ink such as the ink 12 ″ that has been displaced beyond the allowable range is found, the operator instructs the ink ejecting apparatus 10 to maintain the inkjet head 1.

(Confirmation of landing position and pass / fail judgment using image processing device)
Another method for confirming the landing position of the ink 12 and determining the quality is described below with reference to FIGS. FIG. 10 is a flowchart illustrating processing performed by the ink ejecting apparatuses 10, 50, and 70 including the image processing apparatus. FIG. 11 is a plan view showing an image obtained by imaging the inks 12a to 12r ejected from the plurality of nozzles 11a to 11r of FIG. FIG. 12 is a plan view showing an image obtained by imaging the inks 12 a to 12 x ejected from the plurality of nozzles 11 a to x in FIG. 2. FIG. 13 is a plan view showing an example of a method for determining the deviation of the landing position by image processing.

  FIG. 10 shows processes corresponding to steps S6 to S9 in FIG. 4, FIG. 6, or FIG. 8 among the processes of the ink ejecting apparatuses 10, 50, and 70 including the image processing apparatus. Steps not shown are the same as those in FIG. 4, FIG. 6, or FIG.

  As shown in FIG. 10, in step S <b> 6, a plurality of inks 12 ejected on the confirmation printed matter are imaged.

  Based on the image including the plurality of ink 12 images, the image processing apparatus detects the center coordinates of each of the plurality of ink 12 images (step S70). The center coordinates are obtained by determining the center point from the shape of the image of the ink 12, and using the target landing position of each ink 12 as a reference, the distance between the center point and the target landing position and the direction in which the deviation occurs. Represents.

  In the images of the plurality of inks 12, the distance between the center point and the target landing position is equal to or less than or equal to the normal landing position and the magnitude of the positional deviation to be considered. Is determined (step S8). In all of the plurality of ink 12 images, when the distance between the center point and the target landing position is equal to or less than the normal landing position and the magnitude of the positional deviation to be considered ( Yes), it is determined that all of the plurality of inks 12 are normally ejected ink 12. With the above determination, the ink ejecting apparatuses 10, 50, and 70 end the processing.

  On the other hand, in one or more images of the plurality of inks 12, when the distance between the center point and the target landing position is larger than the normal landing position and the magnitude of the positional deviation to be considered (No ), It is determined that there is a nozzle 11 that has performed an abnormal injection. If it is determined that there is a nozzle 11 that has performed abnormal ejection, maintenance of the inkjet head 1 is performed in step S9. When the maintenance of the inkjet head 1 is completed, the ink ejecting apparatuses 10, 50, and 70 end the processing.

(Image 300 and Image 301)
As shown in FIG. 11, an image 300 captured by the camera 2 includes images of a plurality of inks 12 a to 12 r. The image 300 is an image obtained by imaging a printed matter for confirmation in which all of the plurality of inks 12a to 12r have landed normally.

  Among the plurality of inks 12a to 12r, the images of the adjacent inks 12 are arranged at equal intervals. This is because the ink inks 12a to 12r are controlled by the ejection control unit so that the inks 12a to 12r ejected from the nozzles 12a to 12r are arranged like the image 300. The images of the inks 12a to 12r are arranged in 3 rows and 6 columns because the ejection control unit performs the following control.

  First, the inks 12a to 12f are ejected from the nozzles 12a to 12f. The drive unit 4 drives the inkjet head 1 in the X-axis direction and the Y-axis direction. Subsequently, the inks 12g to l are ejected from the nozzles 12g to l. Subsequently, the drive unit 4 drives the inkjet head 1 in the X-axis direction and the Y-axis direction. Finally, the inks 12m to r are ejected from the nozzles 12m to r. That is, the ejection control unit selects the nozzle 11 that performs ejection based on the position of the inkjet head 1.

  The reason why the ejection control unit performs the above control is to include a desired number of images of the ink 12 in the image 300 in accordance with the size of the image 300. Furthermore, by arranging a plurality of inks 12a to 12x at equal intervals, it is easy to distinguish between the normally ejected ink 12 and the ink 12 that has not been ejected normally.

  Here, in the image 300, a plurality of pixels are arranged so that the ratio of the number of pixels to the length and width is 4: 3. What is necessary is just to change suitably the pattern which arrange | positions several ink 12a-r according to arrangement | positioning (ratio of the number of pixels with respect to the height and width) of the pixel of the image 300. FIG.

  As described above, since the images of the plurality of inks 12a to 12r are regularly arranged in the image 300, it is possible to efficiently determine whether or not the landing positions of the plurality of inks 12a to 12r are good at one time.

(Image 301)
As shown in FIG. 12, the image 301 includes images of inks 12a to 12x. Image 301 and image 300 differ in the number of images of ink 12. The image 301 includes images of the inks 11 a to x ejected from all the nozzles 11 a to x formed on the inkjet head 1. The control of the nozzles 11 a to x and the arrangement of the inks 12 a to x are the same as those of the image 300.

  If the images of the inks 11a to 11x ejected from all the nozzles 11a to x are included as in the image 301, it is possible to more efficiently determine whether the landing position of the ink 12 is good or not.

(Arrangement of a plurality of inks 12 in the image 300)
A method for determining the arrangement of the plurality of inks 12 included in the image 300 will be described below with reference to FIG. FIG. 13 is a plan view showing a method for setting a target landing position for a plurality of inks 12.

  As described with reference to FIGS. 11 and 12, by including the images of the plurality of inks 12 in one image 300 or 301, it is possible to efficiently determine whether the landing positions of the plurality of inks 12 are good or bad.

  The number of images of the ink 12 included in one image 300 or 301 may be determined from the size of the area to be regarded as a normal landing position and the size of the image 300 or 301 in the printed matter for confirmation. The size of the area that should be regarded as a normal landing position can be obtained from the degree of positional deviation that should be allowed in the production of the printed material, the ratio between the interval W1 and the interval W2, and the size of the landed ink 12.

  For example, the degree of misalignment to be allowed at the time of production at the time of printing is 10 μm, the interval between the nozzle 11 and the substrate 7 at the time of production at the time of printing is 1 mm, and the nozzle 11 at the time of production at the time of printing for confirmation It is assumed that the distance between the printing material 7 is 3 mm. At this time, the degree of displacement that should be allowed when checking the landing position is 30 μm.

  As shown in FIG. 13, when the radius of the ink 12 that has landed on the substrate 7 is 30 μm, from the landing target position 131 a of the ink 12 a to the outer periphery of the region 132 a that the ink 12 a should be regarded as a normal landing position. The distance is 60 μm. That is, the region 132 to be regarded as a normal landing position has a substantially circular shape with a radius of 60 μm. The distance from the landing target position 131a of the ink 12a to the landing target position 131b of the ink 12b is 120 μm. That is, the normal landing position and the area 132a to be considered are in contact with the normal landing position and the area 132b to be considered. For this reason, when each of the ink 12a and the ink 12b is normally ejected, the ink 12a and the ink 12b do not overlap. Therefore, it is possible to avoid a state where the ink 12a and the ink 12b are deformed and the landing position cannot be specified.

  That is, under the above-described conditions, if the distance from the position 131a to the position 131b is 120 μm or more, it is possible to avoid a state in which a part of the ink 12a and the ink 12b overlap and it is not possible to determine whether the landing position is good or bad.

  Further, it is assumed that the width of the substrate 7 that can be included in the image 300 in the X-axis direction is 900 μm, and the number of inks 12 that are desired to be arranged parallel to the X-axis direction of the image 300 is six. At this time, the distance from the position 131a to the position 131b may be set to 120 μm to 150 μm.

  In summary, in order to quickly and accurately determine the quality of the landing positions of the plurality of inks 12, the interval between the inks 12 and the number of inks 12 included in one image 300 are determined as normal landing positions. It may be determined based on the size of the area to be considered and the size of the image 300.

  When a part of the ink 12a protrudes from the region 132a or overlaps a part of the ink 12b, it is determined that the ink 12a is not ejected normally. If one of the plurality of inks 12 included in the image 300 is determined not to be ejected normally, maintenance of the inkjet head 1 is performed.

(Other configurations)
The present invention can also be expressed as follows.

(First configuration)
An inkjet head in which a plurality of nozzles are formed;
An observation camera for imaging a droplet ejected from the inkjet head;
A printing stand on which the printing material for ejecting the droplets is placed;
Moving means for moving the printing stand, the inkjet head and the observation camera in a horizontal and relative direction;
In a droplet ejection device comprising:
A gap adjusting mechanism for adjusting a gap between the inkjet head and the printing material;
A droplet ejecting apparatus in which the gap adjusting mechanism sets a wider gap than a gap during printing when the landing position of the droplet ejected from the inkjet head is confirmed.

  By having the first configuration, the gap adjustment mechanism that adjusts the gap makes the gap larger than the gap at the time of printing when checking the landing position, so that it is possible to detect a fine shift and the resolution of the observation camera is low. In addition, the cost can be reduced, and a plurality of nozzles can be observed simultaneously, thereby shortening the time required for observation.

(Second configuration)
An inkjet head in which a plurality of nozzles are formed;
An observation camera that images the droplets ejected from the inkjet head;
A printing stand on which the printing material for ejecting the droplets is placed;
An observation table on which an object to be inspected for landing position is placed;
Moving means for relatively moving the printing table and the observation table, the inkjet head and the observation camera in the horizontal direction;
In a droplet ejection device comprising:
A liquid droplet ejecting apparatus, wherein a gap between the inkjet head and the observation table is wider than a gap between the inkjet head and the printing table.

  By having the second configuration, when the landing position is confirmed, the gap becomes larger than the gap at the time of printing, so that it is possible to detect a minute shift, and the cost can be reduced because it can be confirmed even when the resolution of the observation camera is low. In addition, simultaneous observation of a plurality of nozzles is possible, and the time required for observation can be shortened. Furthermore, a dedicated gap adjustment mechanism is not required.

(Third configuration)
An inkjet head in which a plurality of nozzles are formed;
An observation camera for imaging a droplet ejected from the inkjet head;
A printing stand on which the printing material for ejecting the droplets is placed;
Moving means for moving the printing stand, the inkjet head and the observation camera in a horizontal and relative direction;
In a liquid droplet ejecting apparatus comprising:
A droplet ejecting apparatus that uses an inspection printed material that is thinner than the thickness of the printing material used for actual printing when confirming the landing position of the ink ejected from the inkjet head.

  By having the third configuration, when the landing position is confirmed, it becomes wider than the gap at the time of printing, so that it is possible to detect a minute shift, and the cost can be reduced because it can be confirmed even if the resolution of the observation camera is low. In addition, simultaneous observation of a plurality of nozzles is possible, and the time required for observation can be shortened. Furthermore, since a dedicated gap adjusting mechanism and an observation table are not necessary, cost and space can be saved.

(Fourth configuration)
The liquid droplet ejection according to any one of the first to third configurations, further comprising an image monitor that displays an image captured by the observation camera, wherein the landing position is confirmed from the image displayed on the image monitor. apparatus.

  By having the fourth configuration, it is not necessary to perform image processing by observing the image, and the landing position observation system can be simplified. As described above, since the landing deviation is enlarged, it can be easily observed.

(Fifth configuration)
An image processing device for processing an image captured by the observation camera;
The landing position data is formed by processing the image by the image processing device,
The droplet ejecting apparatus according to any one of the first to third configurations, wherein the landing position is confirmed from the processed landing position data.

  By having the fifth configuration, the burden on the apparatus operator is eliminated by performing image processing. As described above, since the landing deviation is enlarged, it can be easily observed.

(Sixth configuration)
The liquid according to any one of the first to third configurations that forms an inspection pattern such that a landing droplet ejected from each of the plurality of nozzles is disposed in an effective pixel of the observation camera. Drop ejector.

(Seventh configuration)
The droplet ejecting apparatus according to any one of the first to third configurations that confirms the landing positions of a plurality of nozzles at a time.

  By having the sixth or seventh configuration, the landing position observation of a plurality of nozzles can be realized at a time using the above-described landing deviation expansion effect, so that the landing deviation observation time can be shortened.

(Eighth configuration)
The liquid according to any one of the first to third configurations in which an inspection pattern is formed so that all the landing droplets of the plurality of nozzles are arranged at equal intervals in the effective pixels of the observation camera. Drop ejector.

(Ninth configuration)
The droplet ejecting apparatus according to any one of the first to third configurations, wherein the landing positions of the ink ejected from all of the plurality of nozzles are confirmed at a time.

(Tenth configuration)
Any of the first to third configurations in which the inspection pattern is determined by an allowable landing deviation amount, a gap between the inkjet head and the printing material, a landing droplet size, and an image size captured by the observation camera. The droplet ejecting apparatus according to claim 1.

  By having the eighth, ninth, or tenth configuration, it is possible to realize the landing position observation of all the nozzles at once using the above-described landing deviation expansion effect, so that the landing deviation observation time can be shortened. .

  The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope shown in the claims, and the embodiments can be obtained by appropriately combining technical means disclosed in different embodiments. Is also included in the technical scope of the present invention.

  By using the present invention, it is possible to accurately and quickly detect a nozzle having a problem in ink ejection using a simple and inexpensive method. Therefore, it can be used for detection of a nozzle defect in an entire manufacturing apparatus using an inkjet method. In particular, it is suitable for application to a manufacturing apparatus such as a color filter substrate or an organic EL (electroluminescence) element used in an image display apparatus.

FIG. 3 is a plan view illustrating a configuration of the ink ejecting apparatus according to the invention as viewed from the side. It is a top view which shows the structure of the inkjet head which concerns on this invention. (A) is a plan view showing the landing position of ink on a medium on which ink for pattern formation has been ejected, and (b) shows the landing position of ink on a medium on which ink has been ejected for confirming the landing position. It is a top view. 2 is a flowchart illustrating processing performed by the ink ejecting apparatus of FIG. 1. FIG. 9 is a plan view illustrating a configuration of an ink ejecting apparatus that is a modification of FIG. 1 as viewed from the side. 6 is a flowchart illustrating processing performed by the ink ejecting apparatus of FIG. 5. (A) is a plan view showing a configuration at the time of pattern formation of an ink ejecting apparatus which is another modified example of FIG. 1, and (b) is at the time of confirming the ink landing position of the ink ejecting apparatus of (a). It is a top view which shows the structure in. It is a flowchart which shows the process which the ink ejecting apparatus of FIG. 7 performs. (A) is a top view which shows the image of the medium which ejected the ink displayed on the monitor, (b) is a top view which shows the sheet | seat which determines the quality of a landing position, (c), It is a top view which shows the state which piled up the sheet | seat of (b) on the image of (a). 4 is a flowchart illustrating processing performed by an ink ejecting apparatus including an image processing apparatus. FIG. 3 is a plan view showing an image obtained by imaging ink ejected from a plurality of nozzles in FIG. 2. FIG. 3 is a plan view showing an image in which ink ejected from all of the plurality of nozzles in FIG. 2 is captured. It is a top view which shows the method of setting the target landing position in several ink.

Explanation of symbols

1 Inkjet head (jetting means)
2 Camera (imaging means)
3 Printing stand (first support stand)
3a Printing stand (second support stand)
6 Drive unit (drive means)
7 Substrate (medium for forming pattern)
7a Substrate (medium for confirming ink landing position)
DESCRIPTION OF SYMBOLS 10 Ink ejector 11 Nozzle 11a-x Nozzle 12 Ink 12 'Ink 12''Ink 50 Ink ejector 70 Ink ejector 100 Image 101 Sheet | seat 132 area | region (area which should be regarded as a normal landing position)
300 images 301 images

Claims (12)

Comprising ink ejecting means for ejecting ink onto a medium via a nozzle;
The ink ejecting means is
When there is a first interval between the medium and the nozzle, the ink for forming a pattern on the medium is ejected onto the medium, and
When there is a second gap wider than the first gap between the medium and the nozzle, the ink for confirming the landing position of the ink on the medium is ejected onto the medium. An ink ejecting apparatus. Drive means for driving the ink ejecting means or the support for supporting the medium in a direction perpendicular to the surface of the medium facing the nozzle;
The driving means is
2. The ink ejection according to claim 1, wherein the ink ejection unit or the support base is driven such that the first interval or the second interval is provided between the medium and the nozzle. apparatus. A first support for supporting the medium for forming the pattern;
A second support for supporting the medium for confirming the landing position,
There is the first interval between the medium placed on the first support and the nozzle,
2. The ink ejecting apparatus according to claim 1, wherein the second space is provided between the medium placed on the second support and the nozzle. 3.   The ink ejecting apparatus according to claim 1, wherein the medium for confirming a landing position of the ink is thinner than the medium for forming the pattern.   The ink ejecting apparatus according to claim 1, further comprising an imaging unit configured to image the ink ejected on the medium for confirming a landing position.   The ink ejecting apparatus according to claim 5, further comprising display means for displaying an image picked up by the image pickup means.   6. The ink ejecting apparatus according to claim 5, further comprising image processing means for performing processing for specifying the landing position of the ink based on an image picked up by the image pickup means.   8. The ink ejecting apparatus according to claim 6, wherein the image is an image obtained by capturing the plurality of inks for confirming a landing position, which is ejected from the plurality of nozzles onto the medium. 9. .   9. The ink according to claim 8, further comprising ejection control means for controlling ejection of the ink of the ink ejection means so that each of the plurality of inks is arranged at an equal interval. Injection device.   The said ejection control means determines the said equal space | interval based on the magnitude | size of the area | region which should be considered with the normal landing position of the said ink, and the magnitude | size of the said image. Ink ejection device.   The display means includes a sheet provided with a mark for distinguishing between a normal landing position and an area to be regarded as an abnormal landing position and an abnormal landing position from the ink. The ink ejecting apparatus according to claim 6. Including an ink ejecting step of ejecting ink from the ink ejecting means onto the medium through a nozzle;
In the ink ejecting step, when the ink ejecting means has a first interval between the medium and the nozzle, the ink for forming a pattern on the medium is ejected onto the medium;
When there is a second gap wider than the first gap between the medium and the nozzle, the ink for confirming the landing position of the ink on the medium is ejected onto the medium. An ink jetting method characterized by the above.

Images