KR102012378B1 - Printing head assembly, printing apparatus and method for aligning printing head - Google Patents

Abstract

The present invention relates to a print head assembly, a printing apparatus and a print head alignment method, and more particularly, to a print head assembly, a printing apparatus and a print head alignment method for aligning a print head.
A print head assembly according to an embodiment of the present invention includes: a first print head and a second print head each having one or more nozzle groups arranged in a row, and disposed adjacent to each other; A first alignment unit coupled to the first print head to move the first print head; A second alignment unit coupled to the second print head to move the second print head relative to the first print head; And a support frame on which the first alignment unit and the second alignment unit are installed.

Description

PRINTING HEAD ASSEMBLY, PRINTING APPARATUS AND METHOD FOR ALIGNING PRINTING HEAD}

The present invention relates to a print head assembly, a printing apparatus and a print head alignment method, and more particularly, to a print head assembly, a printing apparatus and a print head alignment method for aligning a print head.

Recently, as the substrate size of plasma display panels (PDPs) and liquid crystal displays (LCDs) increases in order to improve productivity in the flat panel display industry, conventional photolithography processes using masks have started to show limitations. New technologies are needed that can shorten the process and replace the existing photolithography process.

Printing is a technology for producing a large amount of products using the same pattern plate making, a technology that can easily produce a conductive pattern, image pattern and the like at a low cost. In particular, unlike conventional gravure and screen printing, which require an expensive engraving process, inkjet printing technology can directly reduce the process cost by converting the data into digital signals and patterning them. It is a very suitable technology for small quantity batch production, which is a manufacturing trend.

DoD (Drop on Demand) inkjet is a popular technology developed and developed as a home printer, and if this technology is used for the manufacturing of printed circuit boards (PCB), eco-friendly production processes can increase the component mounting density and reduce the cost. have.

In the inkjet printing technology, the droplets ejected from the print head must be precisely positioned at the corresponding dot positions when ejecting the droplets. If not, the droplets will be sprayed in the wrong place.

In particular, in the case of a multi-head array (MHA) structure using a plurality of print heads, dozens to hundreds of print heads should be attached to one printing apparatus. However, in this case, not only the misalignment of the print heads, but also the manufacturing errors occurring in the manufacturing process of each print head, there is a problem that it is difficult to align each of the plurality of print heads in the correct position.

KR 10-2008-0105669 A

The present invention provides a print head assembly, a printing apparatus, and a print head alignment method capable of aligning the print head efficiently.

A print head assembly according to an embodiment of the present invention includes: a first print head and a second print head each having one or more nozzle groups arranged in a row, and disposed adjacent to each other; A first alignment unit coupled to the first print head to move the first print head; A second alignment unit coupled to the second print head to move the second print head relative to the first print head; And a support frame on which the first alignment unit and the second alignment unit are installed.

In addition, the first alignment unit may move the first print head with less freedom of movement than the second alignment unit.

The first alignment unit may rotate only the first print head, and the second alignment unit may rotate the second print head and linearly move in one direction.

In addition, the printing apparatus according to the embodiment of the present invention, any one of the print head assembly described above; A position acquiring unit for acquiring positions of droplets ejected from the first print head and the second print head from printed matter printed from the first print head and the second print head; A calculating unit calculating a correction value of the first print head and the second print head from a position of the droplet; And a driving unit driving the first alignment unit and the second alignment unit, respectively, according to the correction value.

The driving unit moves the support frame from a first position to a second position in a scan direction, and the position obtaining unit is configured to control the primary droplets ejected from the first print head and the second print head at the first position. And the positions of the secondary droplets ejected from the first print head at the second positions, respectively.

The operation unit may include a line connecting the primary droplets and the secondary droplets ejected from one nozzle of the first print head, and a line connecting the droplets ejected from the plurality of nozzle groups arranged in a line of the first print head. The rotation angle of the first print head may be calculated by comparing the two.

The calculator may include a reference line connecting the primary droplets and the secondary droplets ejected from one nozzle of the first print head, and the droplets ejected from the plurality of nozzle groups arranged in a line of the first print head. The rotation angle of the first print head may be calculated by comparing the first lines.

The operation unit may include a first correction line that rotates the first line along a rotation angle of the first print head, and a second connection line connecting droplets ejected from a plurality of nozzle groups arranged in a line of the second print head. The rotation angle of the second print head can be calculated by comparing the lines.

The calculator may calculate the linear movement distance of the second print head by comparing the second correction line with the first correction line.

A print control unit controlling an injection timing of the first print head and the second print head such that droplets ejected from a plurality of nozzle groups arranged in a row of the first print head and the second print head are sprayed on the same print line; It may further include.

It may further include a print alignment unit for aligning at least one of the position of the support frame and the substrate to be printed.

In addition, the printhead alignment method according to an embodiment of the present invention, the process of calculating the correction value of the first printhead and the second printhead disposed adjacent to the first printhead; Aligning the first print head only by the rotational movement of the first print head according to the correction value; And aligning the second print head by a rotational movement of the second print head and a linear movement in one direction according to the correction value.

Printing a print from the first print head and the second print head before calculating the correction value; Photographing the printed matter; And obtaining positions of droplets ejected from the first print head and the second print head from the photographed image of the printed matter.

The process of acquiring the position of the droplet may be obtained by identifying the position of the primary droplet ejected from a plurality of nozzle groups arranged in a row of the first print head and the second print head, respectively.

The obtaining of the position of the droplet may be performed by simultaneously moving the first print head and the second print head in the scan direction to further confirm the position of the secondary droplet ejected from the first print head.

The calculating of the correction value may include: generating a reference line connecting the primary droplet and the secondary droplet ejected from one nozzle of the first print head; Generating a first line connecting droplets ejected from a plurality of nozzle groups arranged in a line of the first print head; And calculating a rotation angle of the first print head for rotating the first line with a first correction line disposed in a direction perpendicular to the reference line.

The calculating of the correction value may include: generating a second line connecting droplets ejected from a plurality of nozzle groups arranged in a line of the second print head; And calculating a rotation angle of the second print head for rotating the second line to a second correction line disposed in parallel with the first correction line.

The calculating of the correction value may include calculating a linear movement distance of the second print head for disposing the second correction line at a predetermined interval from the first correction line in a direction perpendicular to the reference line. It may further include;

According to the printhead assembly, the printing apparatus, and the printhead alignment method according to an embodiment of the present invention, in a printhead assembly in which a plurality of printheads are assembled, one printhead is moved and aligned, and another printhead adjacent to one printhead is provided. By moving relative to and aligning, it is possible to align a plurality of print heads quickly and accurately.

In addition, it is possible to align the plurality of print heads individually with a minimum of freedom of movement, thereby effectively reducing the time taken for aligning when the print heads are replaced, which enables miniaturization and efficient alignment of the equipment.

In addition, by aligning each print head by using the positional relationship of the droplets ejected from the plurality of print heads, it is possible to calculate correction values reflecting not only misalignment of the print heads but also manufacturing errors occurring during the manufacturing process of the print heads or nozzles. It is possible to align each print head more precisely.

In addition, according to the print head assembly, the printing apparatus, and the print head alignment method according to an embodiment of the present invention, even when the photographing unit for checking the positional relationship of the droplets ejected from each print head is misaligned, an accurate scan direction can be extracted. Using this as a reference line, each print head can be precisely aligned in a direction perpendicular to the scan direction.

1 is a schematic representation of a print head assembly according to an embodiment of the invention.
2 is a view showing a state of the alignment unit according to an embodiment of the present invention.
3 is a schematic view of a printing apparatus according to an embodiment of the present invention.
4 is a view showing a state of obtaining positions of droplets ejected from the first print head and the second print head.
5 is a view showing a state of setting a reference line according to an embodiment of the present invention.
6 is a view showing a state of calculating the rotation angle of the first print head according to an embodiment of the present invention.
7 is a view showing a state of calculating the rotation angle of the second print head according to an embodiment of the present invention.
8 is a view showing a state of calculating the linear movement distance of the second print head according to an embodiment of the present invention.
9 is a view schematically showing a print head alignment method according to an embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various forms, and only the embodiments of the present invention make the disclosure of the present invention complete and the scope of the invention to those skilled in the art. It is provided to inform you completely. Like numbers refer to like elements in the figures.

1 is a view schematically showing a print head assembly according to an embodiment of the present invention, Figure 2 is a view showing the appearance of the alignment unit according to an embodiment of the present invention. 2 (a) is a view showing a state of the first alignment unit 210 according to an embodiment of the present invention, Figure 2 (b) is a view of the second alignment unit 220 according to an embodiment of the present invention. It is a figure which shows a state.

1 and 2, a print head assembly according to an exemplary embodiment of the present invention includes one or more nozzle groups each arranged in a row, and includes a first print head 110 and a second one adjacent to each other. Print head 120; A first alignment unit 210 coupled to the first print head 110 to move the first print head 110; A second alignment part (220) coupled to the second print head (120) to move the second print head (120) relative to the first print head (110); And a support frame 300 on which the first alignment unit 210 and the second alignment unit 220 are installed.

The print head is provided in plurality in spaced intervals. Each print head is formed in a substantially rectangular shape, and a plurality of nozzle groups are provided at least in a row on the lower surface.

The print head has a structure in which ink supplied from the container is ejected into the droplets through a nozzle by using a predetermined ejection means. Here, the injection means may be a heater that generates bubbles by applying heat to the ink and injects the droplets with this force. In addition, the injection means may be a piezoelectric body, in which case droplets may be injected through the nozzle due to a change in the volume of the ink caused by the deformation of the piezoelectric body. In addition, various structures for ejecting droplets from the print head may be applied.

The plurality of print heads may be arranged in a row in the transverse direction, but in this case, the last nozzle of the preceding print head and the first nozzle of the next print head to be disposed should be spaced apart at precise resolution intervals in the transverse direction. However, when a plurality of print heads are arranged in a row in the transverse direction, it is very difficult to meet such a requirement in the arrangement structure of the nozzles.

Thus, as shown in FIG. 1, the plurality of print heads may be arranged in two print head rows spaced apart from each other in the longitudinal direction. That is, the plurality of print heads are arranged in a zigzag form with each other. In this case, the fourth print head 140 and the third print head 130 may be accurately disposed at a resolution interval, which may be compared with the third print head 130 in a relationship between the preceding print head and the following print head. The same applies to the first print head 110, the first print head 110, and the second print head 120.

In addition, the plurality of print heads may be somewhat different in print characteristics, for example, the size of the ejected droplets between the print heads. Thus, in order to alleviate the difference between the droplets ejected by the plurality of print heads, the print heads may be arranged such that nozzles of adjacent print heads overlap each other as shown in FIG. 1. 1 exemplarily illustrates a structure in which four print heads are arranged in a zigzag form, but the number of print heads arranged is not limited thereto. In addition, although FIG. 1 illustrates a structure in which a plurality of nozzle groups are arranged in a row in the print head, the plurality of nozzle groups may be provided in a plurality of rows. In this case, the alignment of the print heads described below can be applied from a row of nozzles in positional positions corresponding to each other in each print head. In addition, hereinafter, only the first print head 110 and the second print head 120 which are disposed adjacent to each other for convenience of description will be described. The same applies to the third print head 130 and the fourth print head 140 disposed adjacent to the third print head 130.

The first alignment unit 210 is coupled to the first print head 110 to move the first print head 110. Here, the first alignment unit 210 is composed of only the first rotation moving unit 214 for rotating the first print head 110 in a direction perpendicular to the spray plane on the central axis to move the first print head 110. It can move with one movement freedom. That is, the first alignment unit 210 couples the first print head 110 to the first print head mounting unit 212 provided in the first rotational moving unit 214, and drives a drive, for example, a servo motor or the like. The first print head 110 may be rotated by the micrometer head in a combination of a worm and a worm sheel.

On the other hand, the second alignment unit 220 is coupled to the second print head 120 to move the second print head 120 relative to the first print head 110. That is, in the print head assembly according to the embodiment of the present invention, in order to align the first print head 110 and the second print head 120 as described below, first, correction for alignment of the first print head 110 is performed. The value is calculated, and then a correction value for alignment of the second print head 120 is calculated to align the second print head 120 relative to the first print head 110.

In addition, the second alignment unit 220 may include a second rotary moving unit 224 for rotating the second print head 120 and a linear moving unit 224 for linearly moving the second print head 120 in one direction. Including the second print head 120 can be moved with two degrees of freedom. That is, the second alignment part 220 couples the second print head 120 to the second print head seating part 222 provided in the second rotational moving part 224, similarly to the first alignment part 210. And the second printing coupled to the second print head seating part 222 through the linear moving part 224 installed to be movable along the guide as well as rotationally moving the second print head 120 by the driving part. The head 120 may be linearly moved in one direction.

In general, in order to align a plurality of print heads, an alignment unit having three movement degrees of freedom capable of linear movement in one direction, linear movement in a direction perpendicular to the one direction, and rotational movement with respect to each print head is printed. It is mounted head by head. However, in this case, there is a problem that it takes a lot of time to align each time the print head is replaced because there is a plurality of freedom of movement for alignment by print head.

For example, when four print heads are installed in the support frame 300, as shown in FIG. 1, an alignment part having three degrees of freedom of movement is provided for each print head, so that the print head assembly has a total of 12 degrees of freedom of movement. Will have However, in the print head assembly according to the exemplary embodiment of the present invention, when four print heads are installed, one print head may include an alignment unit capable of rotating only, for example, a first alignment unit in the first print head 110. 210, and the remaining print heads, for example, the second print head 120, the third print head 130 and the fourth print head 140, the only rotational movement and linear movement in one direction The second alignment unit 220, the third alignment unit 230, and the fourth alignment unit 240 may be installed to have a total of seven movement degrees of freedom. Therefore, the print head assembly according to the embodiment of the present invention has the minimum freedom of movement for the alignment of each print head and can align the print heads individually, so that the equipment can be miniaturized with higher reliability and efficient alignment. This becomes possible.

In addition, the print head assembly may be attached to a print head located inside of one or more degrees of freedom when the three or more print heads are included, that is, an alignment portion for rotating the print head only. That is, when the fourth print head 140, the third print head 130, the first print head 110 and the second print head 120 are sequentially coupled in the horizontal direction, Only the first print head 110 positioned between the fourth print head 140 and the second print head 120 disposed outside may be rotated, and the remaining print heads may be rotated and straight in one direction. By moving, each print head can be aligned. A process of aligning all the print heads by the rotational movement of the first print head 110 and the linear movement and the rotational movement of the second print head 120 will be described later.

The first alignment unit 210 and the second alignment unit 220 are respectively installed in the support frame 300. The first print head 110 and the second print head 120 may be indirectly installed on the support frame 300 by the first aligner 210 and the second aligner 220, respectively. The first print head 110 and the second print head 120 installed in the 300 are integrally moved along the scan direction by a movement along the scan direction of the support frame 300.

3 is a view schematically showing a printing apparatus according to an embodiment of the present invention. In addition, FIG. 4 is a diagram illustrating a state in which the positions of droplets ejected from the first print head 110 and the second print head 120 are obtained, and FIG. 5 is a reference line for setting a reference line according to an embodiment of the present invention. 6 is a view illustrating a state of calculating a rotation angle of the first print head 110 according to an exemplary embodiment of the present invention. 7 is a view showing a state of calculating the rotation angle of the second print head 120 according to an embodiment of the present invention, Figure 8 is a straight line of the second print head 120 according to an embodiment of the present invention It is a figure which shows the state which calculates a moving distance.

3 to 8, a printing apparatus according to an embodiment of the present invention includes a print head assembly according to the embodiment of the present invention described above; Position acquisition unit for obtaining the position of the droplet ejected from the first print head 110 and the second print head 120 from the printed matter printed from the first print head 110 and the second print head 120 (Not shown); An operation unit (not shown) for calculating a correction value including a rotation angle of the first print head 110, a rotation angle of the second print head 120, and a linear movement distance from the position of the droplet; And a driver (not shown) for driving the first alignment unit 210 and the second alignment unit 220, respectively, according to the correction value.

According to an exemplary embodiment of the present invention, the first print head 110 and the second print head 120 are coupled to the first alignment unit 210 and the second alignment unit 220, respectively, and installed on the support frame 300. Since the print head assembly is the same as described above, a duplicate description thereof will be omitted.

The position obtaining unit obtains the positions of droplets ejected from the first print head 110 and the second print head 120 from printed matter printed from the first print head 110 and the second print head 120.

In general, the printing apparatus photographs nozzles provided in each print head to align the print heads, grasps the positions of the nozzles from the photographed images, and calculates and corrects the correction values of the print heads from the positions of the nozzles. Use the method.

However, this is a way to align the print head while looking directly at the position of the nozzle, it is impossible to reflect the position error for the misaligned droplets ejected from the nozzle in the alignment process. That is, even when the nozzles are correctly aligned with the print head, due to manufacturing errors occurring during the manufacturing process of the print head or the nozzles, the droplets sprayed from the nozzles are not exactly positioned at the corresponding dot positions, but are sprayed at the wrong positions. Can be.

On the other hand, the printing apparatus according to the embodiment of the present invention is sprayed from the first print head 110 and the second print head 120 from the printed matter printed from the first print head 110 and the second print head 120 The position of the dropped droplets is obtained, and the first print head 110 and the second print head 120 are aligned using the obtained positional relationship of the droplets. In this case, not only the misalignment of the print heads, but also the manufacturing errors occurring in the manufacturing process of the print head or the nozzle may be reflected so that each print head may be aligned so that each print head may be aligned more precisely.

In order to acquire the position of the droplet from the printed matter printed from the first print head 110 and the second print head 120, the position acquiring unit is first included in the printing apparatus according to the embodiment of the present invention, or is provided separately The printed matter printed from the first print head 110 and the second print head 120 is photographed. Here, the printed matter means a film or a substrate S to which the droplets ejected from the first print head 110 and the second print head 120 are applied, and the photographing unit is installed on the upper portion of the printed matter, or the lower portion of the printed matter. Thus, the printed matter printed from the first print head 110 and the second print head 120 may be photographed. When the photographing unit is installed below the printed matter, the film or the substrate S may use a transparent film or the transparent substrate S. In addition, although the photographing unit may photograph the printed matter printed from the first print head 110 and the second print head 120 at one time, the photographing unit may divide the area into a plurality of photographs, and photograph the photographed areas. In this case, the photographing unit may be installed to be movable, and the images photographed for each region may be synthesized with each other to generate a single image. In addition, the photographing unit may include a camera or nozzle jetting inspection (NJI).

As shown in FIG. 4, the position obtaining unit obtains the positions of the droplets ejected from the first print head 110 and the second print head 120 from the image of the print photographed by the photographing unit. Here, the position acquisition unit may obtain the position of the droplets ejected from the first print head 110 and the second print head 120 as XY coordinates for the image of the printed matter, and is provided in the first print head 110 Positions of droplets D11-1, D11-2, ..., D11-N ejected from a plurality of nozzle groups arranged in a row and sprayed from a plurality of nozzle groups provided in the second print head 120 and arranged in a row The positions of the dropped droplets D12-1, D12-2, ..., D12-N are respectively obtained. Here, the plurality of nozzle groups arranged in a row on the first print head 110 and the nozzles arranged in a row on the second print head 120 are respectively formed in the first print head 110 and the second print head 120. The nozzles may be arranged at mutually corresponding positions.

In addition, as shown in FIG. 5, the position obtaining unit moves the support frame 300 along the guide rail 420 to the positions of the droplets ejected from the first print head 110 and the second print head 120. Can be obtained in plural. That is, the support frame 300 is moved from the first position to the second position along the scanning direction by the driving unit, and the first print head 110 and the second print head 120 are moved in the first position and the second position. Each droplet is sprayed and applied to the film or the substrate S. The photographing unit photographs the printed matter including the film or the substrate S to which the droplets are applied simultaneously or sequentially at the first position and the second position to form an image. Here, the position acquiring unit includes the positions of the first droplets D11-1, D11-2,..., D11 -N and the second print head 120 that are ejected from the first print head 110 at the first position on the photographed image. Reads the positions of the primary droplets D12-1, D12-2, ..., D12-N injected from the second droplet; and the secondary droplets D21-1, injected from the first print head 110 at the second position. The positions of D21-2, ..., D21-N and the positions of secondary droplets D22-1, D22-2, ..., D22-N ejected from the second print head 120 can be obtained, respectively. Here, in the second position, it is possible to check only the position of the droplet ejected from the first print head 110, which is the component of the reference line to be described later, the secondary droplets ejected from the first print head 110. Because it becomes.

As such, the position acquisition unit positions the first droplets ejected from the first print head 110 and the second print head 120 at the first position and the first print head 110 and the second print head at the second position. Acquiring the positions of the secondary droplets ejected from the 120 is to solve the problem that the print head is not aligned correctly due to misalignment of the photographing unit.

That is, only the positions of the droplets ejected from the first print head 110 and the second print head 120 are checked from the photographed image, and the first print head 110 and the second print head 120 are formed by the absolute coordinates on the image. ), When the photographed image is misaligned, it may not be possible to determine the exact alignment position of the first print head 110 and the second print head 120. That is, as shown in FIG. 5, when the Y-axis direction of the captured image does not coincide with the scanning direction of the support frame 300, the first print head 110 and the second print head 120 are moved on the image. In the case of alignment in the X-axis direction, the first print head 110 and the second print head 120 are not aligned at the correct position perpendicular to the scan direction. Accordingly, the printing apparatus according to the embodiment of the present invention confirms both the position of the primary droplet and the position of the secondary droplet as described above from the positioning unit, and thus, the first print head 110 and The second print head 120 can be accurately aligned to a position perpendicular to the scan direction.

The calculating unit calculates a correction value including a rotation angle of the first print head 110, a rotation angle of the second print head 120, and a linear movement distance from the position of the droplet obtained from the position obtaining unit. As described above, the first print head 110 and the second print head 120 are coupled to the first alignment unit 210 and the second alignment unit 220, respectively, and the first alignment unit 210 is the first The print head 110 is rotated only, and the second alignment unit 220 aligns each print head by rotating the second print head 120 and linearly moving in one direction. The correction value including the rotation angle of the first print head 110, the rotation angle of the second print head 120, and the linear movement distance is calculated.

To this end, the calculation unit may be sprayed from a line connecting the primary droplet and the secondary droplet ejected from one nozzle of the first print head 110 and a plurality of nozzle groups arranged in a line of the first print head 110. The rotation angle of the first print head 110 is calculated by comparing the lines connecting the droplets.

That is, the calculation unit may first reference lines R connecting the primary droplets (for example, D11-1) and the secondary droplets (for example, D21-1) injected from one nozzle of the first print head 110. ). As shown in FIG. 5, when the support frame 300 is moved from the first position to the second position, a plurality of nozzles, for example, arranged in a row, of the first print head 110 in the first position The primary droplets (eg, D11-1) sprayed from the nozzles disposed at one end of the nozzle group and the secondary droplets (eg, D21-1) sprayed from the same nozzle at the second position form one line. do. This line becomes the reference line R for determining the scan direction, and as described above, even if the Y-axis direction of the captured image does not coincide with the scan direction of the support frame 300, the first jet is injected from the same nozzle. The position of the droplets and the secondary droplets can be identified and used as a reference line for setting the scan direction.

In addition, the calculation unit generates a first line connecting the droplets (D11-1, D11-2, ..., D11-N) injected from a plurality of nozzle groups arranged in a line of the first print head 110, The first line for rotating the first line to a first correction line D'11-1, D'11-2, ..., D'11-N arranged in a direction perpendicular to the above-described reference line. 1 The rotation angle of the print head 110 is calculated. That is, as shown in FIG. 5, the first lines D11-1, D11-2,..., D11 -N connecting the droplets ejected from the plurality of nozzle groups arranged in a line of the first print head 110. Are not aligned in the scan direction, that is, the direction perpendicular to the reference line. Therefore, the first line is a line connecting the first correction lines D'11-1, D'11-2, ..., D'11-N arranged in a direction perpendicular to the reference line as shown in FIG. Should be rotated to Accordingly, the operation unit adjusts the rotation angle of the first print head 110 to rotate the first line to a first correction line arranged in a direction perpendicular to the reference line about the rotation axis of the first print head 110. The first print head 110 may be accurately aligned in a direction perpendicular to the scan direction when the first print head 110 is rotated at the rotation angle.

The computing unit rotates the line connecting the droplets ejected from the plurality of nozzle groups arranged in a line of the first print head 110 along the rotation angle of the first print head 110 (D'11-1, Lines connecting D'11-2, ..., D'11-N) and droplets ejected from a plurality of nozzle groups arranged in a row of the second print head 120 (D12-1, D12-2, ..., and a line connecting D12-N) to calculate the rotation angle of the second print head 120. That is, as shown in FIG. 6, second lines D12-1, D12-2,..., D12 -N formed by droplets ejected from a plurality of nozzle groups arranged in a row of the second print head 120 are formed. The lines to be connected) are not arranged in the scan direction, that is, the direction perpendicular to the reference line, but are misaligned. Therefore, the second line is a line connecting the second correction lines D'12-1, D'12-2, ..., D'12-N arranged in a direction perpendicular to the reference line as shown in FIG. Should be rotated to Here, in order to rotate the second line to the second correction line, it may be performed in the same manner as the above-described process of disposing the first line in a direction perpendicular to the reference line, but it simplifies the process and provides a quick and efficient process. In order to set the direction perpendicular to the reference line, the step of substituting the second line for the second line may be omitted, and the second print head 120 may be aligned only by comparing the first correction line with the second line. . Accordingly, the calculation unit is configured to rotate the second line formed by the droplets ejected from the plurality of nozzle groups arranged in a line of the second print head 120 to the second correction line arranged in parallel with the first correction line. The rotation angle of the second print head 120 can be calculated, and when the second print head 120 is rotated at the rotation angle, the second print head 120 can be accurately aligned in a direction perpendicular to the scan direction. do.

In addition, the calculation unit is a line (D ') which rotates the line connecting the droplets ejected from the plurality of nozzle groups arranged in a row of the above-described second print head 120 along the rotation angle of the second print head 120. 12-1, D'12-2,..., And D'12-N, and a line connecting droplets ejected from a plurality of nozzle groups arranged in a row of the first print head 110. The second print head (compared to the lines D'11-1, D'11-2, ..., and D'11-N) rotated along the rotation angle of the first print head 110 may be compared. The linear movement distance of 120 can be calculated. That is, as shown in FIG. 7, the first correction lines D'11-1, D'11-2, ..., and D'11-N connect the lines with the second correction line D'12-1. , Lines D'12-2, ..., D'12-N are not aligned with each other along the direction perpendicular to the scan direction. Accordingly, the first correction line and the second correction line are droplets D11 ′ -N injected from the nozzles disposed at the other ends of the adjacent first correction lines and the droplets injected from the nozzles disposed at one end of the second correction line ( The mutual spacing of D12'-1) is not aligned. Therefore, as shown in FIG. 8, the second correction line is linearly moved to adjust the distance from the first correction line along the direction perpendicular to the scan direction, thereby correcting (D ″ 12-1 and D ″ 12-2). , ..., the line connecting D''12 -N). Here, since the first print head 110 can be rotated only by the first alignment unit 210, the interval must be adjusted by the linear movement of the second print head 120. Accordingly, the calculation unit may calculate the linear movement distance of the second print head 120 for arranging the second correction line at a predetermined interval with the first correction line in a direction perpendicular to the reference line. 2 When the print head 120 is linearly moved by the linear movement distance, the first print head 110 and the second print head 120 are disposed at the other end of the nozzles arranged in a line of the first print head 110. The nozzles disposed at one end of the nozzles and the nozzles arranged in a row of the second print heads 120 may be spaced apart at intervals of resolution or may be arranged to overlap each other in the scanning direction as shown in FIG. 8.

As described above, when the correction value including the rotation angle of the first print head 110, the rotation angle of the second print head 120, and the linear movement distance is calculated, the driving unit drives the first alignment unit 210. 1 rotates and aligns the print head 110 by the calculated rotation angle, and drives the second alignment unit 220 to rotate the second print head 120 by the calculated rotation angle and by the calculated linear movement distance. Align by moving straight. In addition, the driving unit may drive other components that require driving in addition to the first alignment unit 210 and the second alignment unit 220.

By this process, the first print head 110 and the second print head 120 can be accurately aligned in a direction perpendicular to the scan direction with a set interval. Here, the first print head 110 can be rotated only by the first alignment unit 210, the second print head 120 is only linear movement in one direction by the second alignment unit 220. If possible, the first print head 110 and the second print head 120 may not be aligned in the scan direction by the above process. However, such alignment along the scanning direction of the first print head 110 and the second print head 120 may be performed in software by the print control unit of the printing apparatus. The print control unit may include the first print head 110 so that the droplets ejected from the plurality of nozzle groups arranged in a row of the first print head 110 and the second print head 120 are sprayed on the same line. The injection timing of the second print head 120 may be adjusted. For example, when the first print head 110 is disposed forward or backward in the scan direction than the second print head 120 or other print heads including the second print head 120, the first print head 110. Adjust the jetting time of the droplets injected from the upper or lower than the jetting time of the droplets injected through the other print head to perform alignment along the scanning directions of the first print head 110 and the second print head 120. Can be.

In addition, the printing apparatus according to an embodiment of the present invention may further include a print alignment unit for aligning at least one of the position of the support frame 300 and the substrate (S) to be printed. That is, as described above, the first print head 110 is coupled to the first alignment unit 210 capable of rotational movement only, and the other print heads including the second print head 120 are the first print head 110. Since the first print head 110 and the second print head 120 need to be integrally aligned along a direction perpendicular to the scanning direction, the first print head 110 and the second print head 120 need to be aligned. Therefore, the printing apparatus according to the embodiment of the present invention is sprayed from the first print head 110 and the second print head 120 by moving the support frame 300 or the substrate S in a direction perpendicular to the scan direction. The droplets to be applied can be applied to the correct position on the substrate (S). Here, when the support frame 300 is moved, problems such as particles due to the movement of the support frame 300 may occur. Preferably performed.

Hereinafter, a print head alignment method according to an embodiment of the present invention will be described. In the description of the print head alignment method according to an embodiment of the present invention, the description overlapping with the above-described print head assembly and the printing apparatus according to the embodiment of the present invention will be omitted.

9 is a view schematically showing a print head alignment method according to an embodiment of the present invention.

Referring to FIG. 9, in the print head alignment method according to an exemplary embodiment of the present invention, a correction value of the first print head 110 and the second print head 120 disposed adjacent to the first print head 110 is determined. Calculating (S100); Aligning the first print head 110 only by the rotational movement of the first print head 110 according to the correction value (S200); And aligning the second print head 120 by a rotational movement of the second print head 120 and a linear movement in one direction according to the correction value (S300).

In the operation S100 of calculating a correction value, the correction value of the first print head 110 and the second print head 120 disposed adjacent to the first print head 110 are calculated. Here, the correction value includes the rotation angle of the first print head 110 and the rotation angle of the second print head 120 and the linear movement distance.

The process of calculating the correction value (S100) is performed by acquiring the positions of the droplets ejected from the first print head 110 and the second print head 120. Therefore, the print head alignment method according to an embodiment of the present invention, before the step (S100) of calculating the correction value, the process of printing the printed matter from the first print head 110 and the second print head 120; Photographing the printed matter; And acquiring positions of droplets ejected from the first print head 110 and the second print head 120 from the photographed image of the printed matter.

The printing of the printed matter is performed by spraying droplets from the first print head 110 and the second print head 120 to print the printed matter. Here, the printed matter means the film or the substrate S to which the droplets ejected from the first print head 110 and the second print head 120 are applied as described above, and the printed matter is the support frame 300. The first print head 110 and the second print head 120 may be simultaneously moved by the movement along the scan direction of the first film and the substrate (S) may be a printed material formed simultaneously with the first droplet and the second droplet. .

In the process of photographing the printed matter, the printed matter printed from the first print head 110 and the second print head 120 is photographed from the photographing unit installed on the upper portion of the printed matter or under the printed matter. Here, the photographing unit may include a camera or nozzle jetting inspection (NJI), and the photographing unit is installed at the upper portion of the printed matter or is installed at the lower portion of the printed matter to print from the first print head 110 and the second print head 120. Printed images can be taken.

The process of acquiring the position of the droplet acquires the position of the droplet ejected from the first print head 110 and the second print head 120 from the photographed image of the printed matter. The process of acquiring the positions of the droplets ejected from the first print head 110 and the second print head 120 from the photographed image of the printed matter is performed by the position acquiring unit, and the position acquiring unit is the first print head 110. And a position of droplets ejected from the second print head 120 as XY coordinates for the image of the printed matter, and the liquids ejected from the plurality of nozzle groups provided in the first print head 110 and arranged in a line. The positions of the enemies and the positions of the droplets ejected from the plurality of nozzle groups provided in the second print head 120 and arranged in a row are respectively obtained.

In addition, the process of acquiring the position of the droplet may simultaneously move the first print head 110 and the second print head 120 in the scan direction to determine the position of the secondary droplet ejected from the first print head 110. It may be obtained by further checking. That is, as described above, the support frame 300 is moved from the first position to the second position along the scanning direction by the driving unit, and the first print head 110 and the second print head 120 have the first position and Droplets are respectively sprayed at the second position and applied to the film or substrate (S). Here, the position acquiring unit is a position of the primary droplet ejected from the first print head 110 and the second print head 120 in the first position on the photographed image and the first print head 110 and the first position in the second position. The positions of the secondary droplets ejected from the two print heads 120 can be obtained respectively.

The calculating of the correction value (S100) may include: generating a reference line connecting the primary droplet and the secondary droplet ejected from one nozzle of the first print head 110; Generating a first line connecting droplets ejected from a plurality of nozzle groups arranged in a line of the first print head 110; And calculating a rotation angle of the first print head 110 to rotate the first line to a first correction line arranged in a direction perpendicular to the reference line.

That is, in order to calculate the rotation angle of the first print head 110, the calculation unit first generates a reference line connecting the primary droplet and the secondary droplet ejected from one nozzle of the first print head 110. In addition, the operation unit generates a first line connecting the droplets ejected from the plurality of nozzle groups arranged in a line of the first print head 110, and arranges the first line in a direction perpendicular to the above-described reference line. A rotation angle of the first print head 110 for rotating with the first correction line is calculated. By this process, the calculation unit is the first print head 110 for rotating the first line to the first correction line arranged in a direction perpendicular to the reference line about the axis of rotation of the first print head 110 The rotation angle may be calculated, and when the first print head 110 is rotated at the rotation angle, the first print head 110 may be accurately aligned in a direction perpendicular to the scan direction.

In addition, the step (S400) of calculating a correction value may include generating a second line connecting droplets ejected from a plurality of nozzle groups arranged in a line of the second print head 120; And calculating a rotation angle of the second print head 120 to rotate the second line to a second correction line disposed in parallel with the first correction line.

That is, the calculation unit generates a line connecting the droplets ejected from the plurality of nozzle groups arranged in a line of the second print head 120 as a second line, and arranges the second line in parallel with the first correction line. A rotation angle of the second print head 120 for rotating with the second correction line may be calculated. In this case, when the second print head 120 is rotated at the rotation angle, the second print head 120 can be accurately aligned in a direction perpendicular to the scan direction.

In addition, the operation (S400) of calculating a correction value may be performed by the second print head 120 for arranging the above-described second correction line at a predetermined interval from the first correction line in a direction perpendicular to the reference line. The method may further include calculating a straight movement distance.

In this case, since the first print head 110 can rotate only by the first alignment unit 210, the interval of the first print head 110 must be adjusted by the linear movement of the second print head 120. Accordingly, the calculation unit may calculate the linear movement distance of the second print head 120 for arranging the second correction line at a predetermined interval with the first correction line in a direction perpendicular to the reference line. 2 When the print head 120 is linearly moved by the linear movement distance, the first print head 110 and the second print head 120 are disposed at the other end of the nozzles arranged in a line of the first print head 110. As described above, the nozzles disposed at one end of the nozzles and the nozzles arranged in a line of the second print head 120 may be disposed to be spaced apart at intervals of resolution or overlapped along the scanning direction.

The process of aligning the first print head 110 (S200) is performed by rotating only the first print head 110 according to the correction value calculated by the above process, that is, the rotation angle of the first print head 110. 1 Align the print head 110. Here, the first print head 110 is coupled to the first alignment unit 210, the first alignment unit 210 for rotating the first print head 110 to rotate in the center axis in the direction perpendicular to the spray surface It consists of only the 1st rotational movement part 214. Therefore, in the process of aligning the first print head 110 (S200), the first print head 110 may be moved only by the rotational movement of the first print head 110 by the first alignment unit 210 driven by the driving unit. You can sort.

The process of aligning the second print head 120 (S300) is performed according to the correction value calculated by the above process, that is, the rotation angle and the linear movement distance of the second print head 120. The second print head 120 is aligned by the rotational movement and the linear movement in one direction. Here, the movement of the Zen print head and the linear movement in one direction may be sequentially performed. The second print head 120 is coupled to the second alignment unit 220, and the second alignment unit 220 is a driving unit. The second print head 120 coupled to the second print head seating portion 222 through the linear moving portion 224 is installed not only to rotate the second print head 120, but also to move along the guide. ) Can be linearly moved in one direction, so that the second print head 120 can be aligned by the rotational movement and the linear movement of the second print head 120 by the second alignment unit 220.

In addition, the print head alignment method according to an embodiment of the present invention is such that the droplets sprayed from a plurality of nozzle groups arranged in a row of the first print head 110 and the second print head 120 is sprayed on the same line. And adjusting the injection timing of the first print head 110 and the second print head 120.

That is, in order to perform software alignment of the first print head 110 and the second print head 120 along the scanning direction, the print controller may control the first print head 110 and the second print head 120. The spraying timing of the first print head 110 and the second print head 120 can be adjusted so that the droplets sprayed from the plurality of nozzle groups arranged in a line are sprayed on the same line.

In addition, the print head alignment method according to an embodiment of the present invention may further include the step of aligning at least one of the position of the support frame 300 and the printed substrate (S).

That is, the first print head 110 is coupled to the first alignment unit 210 capable of rotational movement only, and other print heads including the second print head 120 are aligned positions of the first print head 110. Since the first print head 110 and the second print head 120 need to be integrally aligned along a direction perpendicular to the scan direction. Therefore, the droplets ejected from the first print head 110 and the second print head 120 by moving the supporting frame 300 or the substrate S along the direction perpendicular to the scanning direction are accurately positioned on the substrate S. It can be applied to.

In the above, while the preferred embodiment of the present invention has been described and illustrated using specific terms, such terms are only for clearly describing the present invention, and the embodiments of the present invention and the described terms are used in the technical spirit of the following claims. It is obvious that various changes and modifications can be made without departing from the scope of the present invention. Such modified embodiments should not be understood individually from the spirit and scope of the present invention, but should fall within the claims of the present invention.

110: first print head 120: second print head
210: first alignment portion 212: first print head seating portion
214: first rotary moving unit 220: second alignment unit
222: second print head seating portion 224: second rotational moving portion
226: linear moving part 300: support frame
410: stage 420: guide rail

Claims (17)

delete delete delete A first print head and a second print head disposed adjacent to each other with one or more nozzle groups each arranged in a row; a first alignment part coupled to the first print head to move the first print head; And a second alignment portion coupled to the second print head to move the second print head relative to the first print head, and a support frame provided with the first alignment portion and the second alignment portion. Head assembly;
A position acquiring unit for acquiring positions of droplets ejected from the first print head and the second print head from printed matter printed from the first print head and the second print head;
A calculating unit calculating a correction value of the first print head and the second print head from a position of the droplet; And
And a driving unit driving the first alignment unit and the second alignment unit, respectively, according to the correction value.
The driving unit moves the support frame from the first position to the second position in the scan direction,
The position acquisition unit,
A position of the first droplet ejected from the plurality of nozzle groups arranged in a row of the first print head and the second print head in the first position, and from one nozzle of the first print head in the second position Acquire the positions of the secondary droplets, respectively,
The calculation unit,
A reference line is set by connecting the primary droplets and the secondary droplets ejected from one nozzle of the first print head in the scanning direction, and the droplets ejected from the plurality of nozzle groups arranged in a row of the first print head. And a direction of rotation of the first print head by comparing a direction of a first line to be connected with a direction of the reference line.
delete delete The method according to claim 4,
The calculation unit,
A first correction line for rotating the first line along a rotation angle of the first print head, and a second line connecting droplets ejected from a plurality of nozzle groups arranged in a row of the second print head, And a printing device for calculating a rotation angle of the second print head.
The method according to claim 7,
The calculation unit,
And a second correction line obtained by rotating the second line along the rotation angle of the second print head and the first correction line to calculate a linear movement distance of the second print head.
The method according to claim 4,
A print control unit controlling an injection timing of the first print head and the second print head such that droplets ejected from a plurality of nozzle groups arranged in a row of the first print head and the second print head are sprayed on the same print line; Printing apparatus further comprising a.
The method according to claim 4,
And a print alignment unit to align at least one of the support frame and the position of the substrate to be printed.
Printing a print from the first print head and the second print head;
Photographing the printed matter; And
Obtaining positions of droplets ejected from the first print head and the second print head from the photographed image of the printed matter;
Calculating correction values of the first print head and the second print head;
Aligning the first print head only by the rotational movement of the first print head according to the correction value; And
And aligning the second print head by a rotational movement of the second print head and a linear movement in one direction according to the correction value.
The process of obtaining the position of the droplet,
The first droplet is ejected from a plurality of nozzle groups arranged in a row of the first print head and the second print head, and the first print head and the second print head are simultaneously moved in a scanning direction to provide the first print head. Acquire and confirm the position of the secondary droplets ejected from one nozzle of the print head,
The process of calculating the correction value,
Generating a reference line connecting the primary droplet and the secondary droplet ejected from one nozzle of the first print head in a scan direction;
Generating a first line connecting droplets ejected from a plurality of nozzle groups arranged in a line of the first print head; And
Comparing the direction of the first line and the direction of the reference line, to calculate the rotation angle of the first print head for rotating the first line to the first correction line arranged in a direction perpendicular to the reference line Process; including a printhead alignment method.
delete delete delete delete The method according to claim 11,
The process of calculating the correction value,
Generating a second line connecting droplets ejected from a plurality of nozzle groups arranged in a row of the second print head; And
And calculating a rotation angle of the second print head for rotating the second line to a second correction line arranged in parallel with the first correction line.
The method according to claim 16,
The process of calculating the correction value,
Calculating a linear movement distance of the second print head for arranging the second correction line at a predetermined interval with the first correction line in a direction perpendicular to the reference line; .

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