KR20210108890A - Inkjet printing method and inkjet printing apparatus - Google Patents

Abstract

Provided is an inkjet printing method, which comprises: a first step of reading data of impact position dislocation characteristics from a memory unit (110) for memorizing the obtained impact position dislocation characteristics on the basis of impact position dislocation from a target position of a droplet discharged from an inkjet head (8), with respect to first and second rotation angels, which are different from each other; and a second step of obtaining a target rotation angle of the inkjet head (8), and generating a printing pattern corresponding to the target rotation angle, on the basis of an arrangement pitch of a droplet discharge nozzle of the inkjet head (8) and an application target pitch of an object (1) to be applied in a direction orthogonal to a scanning direction. Accordingly, an impact pitch of a droplet and an application target pitch of an application target unit can match each other at high precision.

Description

Inkjet printing method and inkjet printing apparatus

The present invention relates to an inkjet printing apparatus and an inkjet printing method using the same, and more particularly, to a method for adjusting the coating pitch of an inkjet head.

In recent years, the method of manufacturing a device using an inkjet printing apparatus attracts attention. The inkjet printing apparatus has a plurality of nozzles that discharge droplets, and discharges droplets from the nozzles while controlling the positional relationship between the nozzles and the application target portion of the printing object. Thereby, the inkjet printing apparatus applies a droplet to the application|coating target part of a printing object. As the print object, there is a print object in which application target portions of the print object are arranged at a constant pitch, typified by a display device.

The inkjet printing apparatus rotates an inkjet head in which a plurality of nozzles are arranged at a constant pitch about a rotational axis in a direction normal to a surface of an object to be printed. Thereby, the method of apply|coating according to the pitch of the application|coating target part of an application|coating target with the pitch of the droplet which impacted is disclosed by Unexamined-Japanese-Patent No. 2001-108820 (henceforth "patent document 1"). has been

The conventional method disclosed in Patent Document 1 will be described with reference to Figs. 14A, 14B and 15 . 14A and 14B are diagrams showing the positional relationship between the pitch of the application target portion and the droplet ejection nozzles of the inkjet head. 15 : is a figure which shows the operation|movement flow which adjusts the pitch of the conventional application|coating target part, and the impact pitch of the droplet which was discharged from the inkjet head and landed on the board|substrate.

14A and 14B are an inkjet head 108 , a droplet ejection nozzle 117 of the inkjet head 108 , a substrate 119 , an application target portion 101 on the substrate 119 , and an application target portion The droplet 118 etc. which were made to hit 101 are shown.

FIG. 14A shows a case in which the application target pitch W ₁ of the application target portion 101 is equal to the pitch L of the droplet discharge nozzle 117 . On the other hand, FIG. 14B shows a case where the target application pitch W ₂ of the application target portion 101 is smaller than the pitch L of the droplet discharge nozzles 117 .

14A and 14B , the inkjet head 108 and the substrate 119 discharge droplets from the droplet ejection nozzle 117 while moving relative to the X direction shown in the figure to the application target portion 101 . configured to apply droplets. At this time, when the application target pitch W ₂ of the application target portion 101 is smaller than the pitch L of the droplet discharge nozzles 117 , the inkjet head 108 is rotated at an angle θ, as shown in FIG. 14B . by rotating, it is configured to match the pitch of the Y direction of the liquid discharge nozzle 117, the coating target pitch (W ₂₎ of the coating and the target portion 101.

In the above conventional method, the operation of matching the pitch of the droplet 118 discharged from the droplet discharge nozzle 117 and landing on the substrate 119 in the Y direction with the pitch of the application portion 101 of the substrate 119 . will be described with reference to FIG. 15 .

In addition, as shown in FIG. 15, the said operation|movement consists of 10 steps of step S1 - step S10.

Specifically, "drawing the pattern for adjustment" of step S1 is a step of applying a test pattern for measuring droplet pitch, and "inputting the drawn pattern with a sensor" of step S2 is a step of bringing the test pattern to a camera or the like. . In addition, the "dot cutting process" of step S3 is a step of cutting out a droplet portion from the data obtained in step S2, and the "dot center of gravity calculation process" of step S4 is This is the step to calculate the center of gravity. In addition, in the "R pitch calculation, G pitch calculation, B pitch calculation" of step S5, the impact of each R, G, and B impact droplet from the center of gravity position of each R, G, and B impact droplet calculated|required in step S4 This is the step to calculate the pitch. In addition, "the pitch calculation between RGs, the pitch calculation between GB" of step S6 is the impact pitch between RGs and the impact between RGs and the impact between GB from each center of gravity position of the R impact droplet, G impact droplet, and B impact droplet extracted in step S4 This is the step to calculate the pitch. "Is each RGB pitch a predetermined distance?" of step S7 is a step of determining whether the impact pitch of each impact droplet of R, G, and B computed in step S5 has become a target distance. "Are the pitch between RGs and the pitch between GBs a predetermined distance?" of step S8 is a step of determining whether the impact pitch between RGs and the impact pitch between GBs calculated in step S6 becomes the target distance. . "Adjusting the Y-axis of the drawing head" of step S9 is a step of moving the drawing head in the Y direction and positioning it when the impact pitch between RGs and the impact pitch between GBs do not become the target distances in step S8. And "adjusting the (theta) axis of a drawing head" of step S10 is a step of adjusting the (theta) rotation of a drawing head, when each RGB impact pitch does not become the target distance in step S7.

That is, the conventional method prints a test pattern in step S1, and detects the impact position of the droplet of a test pattern in steps S2 - S4. Moreover, in step S5, each impact pitch of R, G, and B is computed, and in step S7, it is determined whether the impact pitch agrees with a target value. And when an impact pitch does not agree with a target value, in step S10, (theta) rotation adjustment of a drawing head is performed, and it carries out again from the test print of step S1 again after that. Moreover, after all the impact pitches of R, G, and B coincide with the target value, it is further determined by step S8 whether the impact pitch between RGs calculated in step S6, and the impact pitch between GB agree with the target value. do. And after performing Y-axis adjustment in step S9 when the impact pitch between RG and between GB does not agree with a target value, it carries out again from the test print of step S1 again.

As mentioned above, in the conventional method, whenever the pitch of an application|coating target part changes, test printing is performed and the impact pitch of the droplet is measured. And based on the measurement result, it was necessary to further fine-tune a rotation angle, and to repeatedly perform adjustment of a rotation angle and adjustment of a Y direction until it enters into the target threshold value. Even in the case of this method, when the precision is low and the target threshold is large, since it can be adjusted by the said 1-2 times adjustment process, it does not become a problem so much.

However, it is necessary to make small the pitch of an application|coating target part while the request|requirement with respect to high definition of a display device increases in recent years. Therefore, it is necessary to precisely position the impact pitch of the droplet discharged from the nozzle. When apply|coating to a high-definition display device, the shift|offset|difference of the slight impact position by the discharge angle wall of the droplet discharged from each nozzle, and the deviation|shift of the impact position by the relative movement of an application|coating object and an inkjet head, It greatly affects the accuracy of the application position.

Therefore, in the conventional method, when applying to a high-definition display device, whenever the pitch of the application target part changes, the normal printing operation is stopped, and the operation of adjusting the impact pitch is repeated multiple times. There is a need. As a result, the operation rate of the inkjet printing apparatus falls. Moreover, in order to adjust an impact pitch, it is also necessary to prepare the board|substrate for exclusive use of a test, or to form a wide test print area in the board|substrate for production.

The present invention provides an inkjet printing method capable of accurately aligning an impact pitch of droplets with a pitch of an application target portion with high accuracy by determining the optimal rotational amount of the head even when the pitch of the application target portion of the object to be coated changes, and inkjet printing using the same provide the device.

One aspect of the present invention is an inkjet printing method in which droplets are discharged from the inkjet head while the inkjet head is relatively scanned with respect to the application object to apply ink on the application object. In the inkjet printing method, the impact positional shift characteristic calculated|required based on the impact position shift from the target position of the droplet discharged from the inkjet head in each of the 1st rotation angle and 2nd rotation angle from which an inkjet head differs from each other The 1st step of reading the data related to an impact position shift characteristic is included from the memory|storage part which memorize|stores. Moreover, while calculating|requiring the target rotation angle of an inkjet head based on the impact position shift characteristic, the arrangement pitch of the droplet discharge nozzle of an inkjet head, and the application|coating target pitch in the direction orthogonal to a scanning direction, and a second step of generating a print pattern corresponding to the rotation angle. And, based on the target rotation angle and the printing pattern, a third step of controlling the inkjet head to discharge the droplets to the application target portion on the application object is included.

Another aspect of the present invention is an inkjet printing apparatus for discharging droplets from the inkjet head while scanning the inkjet head relative to the application object to apply ink onto the application object. Inkjet printing apparatus, the impact positional shift characteristic calculated|required based on the impact position shift from the target position of the droplet discharged from the inkjet head in each of the 1st rotation angle and 2nd rotation angle from which an inkjet head differs from each other A memory unit to remember is provided. Moreover, while calculating|requiring the target rotation angle of an inkjet head based on the impact position shift characteristic, the arrangement pitch of the droplet discharge nozzle of an inkjet head, and the application|coating target pitch in the direction orthogonal to a scanning direction, and a calculating unit that generates a print pattern corresponding to the rotation angle. And based on the target rotation angle and the printing pattern, it is comprised so that an inkjet head may be controlled to discharge a droplet to the application|coating target part on the application|coating object.

According to the above aspect of the present invention, even if the pitch of the application target portion of the object to be coated changes, the inkjet printing method capable of matching the landing pitch of droplets discharged from the inkjet head to the pitch of the application target portion, and an inkjet printing apparatus using the same can do.

1 is a perspective view of an inkjet printing apparatus according to an example of the embodiment.
It is a top view which shows the board|substrate of the application|coating object which concerns on an example of embodiment.
It is a top view explaining the impact position shift by the discharge angle wall of the droplet discharged from an inkjet head.
It is a side view explaining the impact position shift by the discharge angle wall of the droplet discharged from the inkjet head.
It is a top view explaining the impact position shift by the discharge angle wall of a droplet when the rotation angle of an inkjet head is 0 degree|times.
It is a top view explaining the impact position shift by the discharge angle wall of a droplet when the rotation angle of an inkjet head is (phi) degree.
It is a top view explaining the impact position of the droplet discharged from the inkjet head in case an application|coating target object is still.
It is a side view explaining the impact position of the droplet discharged from the inkjet head in case an application|coating target object is still.
It is a top view explaining the impact position of the droplet discharged from the inkjet head at the time of the application|coating object traveling|works.
It is a side view explaining the impact position of the droplet discharged from the inkjet head at the time of the application|coating target object traveling.
7 : is a top view explaining the impact position of the ejected droplet when it is a case where an application|coating object runs and the rotation angle of an inkjet head is 0 degree|times.
8A is a plan view for explaining the Y-direction position shift between the impact position of the ejected droplet and the application target portion of the application object when the application object travels and the rotation angle of the inkjet head is 0 degrees.
Fig. 8B is a plan view illustrating the impact position of the ejected droplet and the distance in the X direction of the Y axis when the application object travels and the rotation angle of the inkjet head is 0 degrees.
It is a top view explaining the impact position at the time of correct|amending the ejection timing so that it may become a case where an application|coating object drive|works, and the impact position when the rotation angle of an inkjet head is 0 degree|times on a Y-axis.
It is a top view explaining the impact position of a droplet at the time of printing on the application|coating target object in the state which corrected the discharge timing so that the rotation angle of an inkjet head may be 0 degree, and the impact position may become on the Y-axis.
Fig. 8E is an enlarged view of part A of Fig. 8D.
9A is a plan view for explaining the displacement amount in the Y-direction between the impact position of the ejected droplet and the application target portion of the application object when the application object travels and the rotation angle of the inkjet head is θ degrees.
Fig. 9B is a plan view illustrating the impact position of the ejected droplet and the distance in the X direction of the Y axis when the application object travels and the rotation angle of the inkjet head is θ degree.
It is a top view explaining the impact position at the time of a case where an application|coating object drive|works and correct|amends the discharge timing so that the impact position when the rotation angle of an inkjet head is θ degree becomes on the Y-axis.
It is a top view explaining the impact position of a droplet at the time of printing on the application|coating object in the state which corrected the discharge timing so that the rotation angle of an inkjet head might be θ degrees and the impact position would be on the Y-axis.
Fig. 9E is an enlarged view of part A of Fig. 9D.
10A is a plan view for explaining the displacement amount in the Y direction between the impact position of the ejected droplet and the application target portion of the application object when the application object travels and the rotation angle of the inkjet head is φ degrees.
10B is a plan view illustrating the impact position of the ejected droplet and the distance in the X direction of the Y axis when the application object travels and the rotation angle of the inkjet head is φ _{c degree.}
It is a top view explaining the impact position at the time of correct|amending the discharge timing so that it may become a case where an application|coating object drive|works, and _{the impact position when the rotation angle of an inkjet head is (phi) c degree|times on a Y-axis.}
It is a top view explaining the impact position of a droplet at the time of apply|coating to the application object in the state which corrected the discharge timing so that the rotation angle of an inkjet head might be phi _{c degree, and the impact position might be on the Y-axis.}
FIG. 10E is an enlarged view of part A of FIG. 10D .
11 : is a top view explaining the impact position before and behind the (theta) degree rotation of the inkjet head in the case where the application|coating target object is being scanned at the speed V. FIG.
12 : is a top view explaining the impact position at the time of rotating the inkjet head in (phi) degree in the case where an application|coating target object is scanning at the speed|rate V.
13 : is a top view explaining the impact position before and behind (theta) degree rotation of the inkjet head in the case where an application|coating target object is still.
14A is a view for explaining a case in which the inkjet head is adjusted so as to match the pitch of the application target portion of the application object in the prior art.
14B is a view for explaining a case in which the inkjet head is adjusted so as to match the pitch of the application target portion of the application object in the prior art.
15 is a flowchart for adjusting the pitch of the application target portion of the application object and the pitch of droplets discharged from the inkjet head in the conventional example.

(embodiment)

Hereinafter, the inkjet printing apparatus 40 which concerns on this embodiment is divided and demonstrated, referring drawings.

(Configuration of inkjet printing device)

First, the entire configuration of the inkjet printing apparatus 40 according to an example of the present embodiment will be described with reference to FIG. 1 .

1 is a perspective view of an inkjet printing apparatus 40 according to an example of the present embodiment.

As shown in FIG. 1 , the inkjet printing apparatus 40 of the present embodiment includes at least a mount 18 for supporting the apparatus, and a table 17 provided on the mount 18 . ), a substrate transfer stage 30 , a head unit 32 , a head unit transfer stage 33 , two supporting parts 16 , and the like. The substrate transfer stage 30 transfers the substrate provided on the surface plate 17 in the X direction. The head unit transfer stage 33 conveys the head unit 32 in the Y direction orthogonal to the substrate transfer stage 30 . The two support parts 16 support both ends of the head unit transfer stage 33 on the surface plate 17 .

The substrate transfer stage 30 includes a guide rail 5 for substrates, a substrate transfer slider 4 guided by the guide rail 5 for substrates and slidably supported in the X direction, and a substrate transfer slider 4 . It is comprised by the board|substrate rotation mechanism 3 provided on the board|substrate rotation mechanism 3, the board|substrate adsorption|suction table 2 etc. provided above the board|substrate rotation mechanism 3 . The substrate conveyance slider 4 is feedback-controlled by the linear motor 6 for board|substrate conveyance, the board|substrate conveyance position detection part 7, and the board|substrate conveyance stage control part not shown.

Moreover, the board|substrate rotation mechanism 3 is equipped with the board|substrate rotation angle detection part and the board|substrate rotation drive part which are not shown in figure. The substrate rotation mechanism 3 is configured to be precisely positioned at a target rotation angle by a substrate rotation mechanism control unit (not shown).

On the other hand, the head unit transfer stage 33 includes a head unit transfer guide rail 13 and a head unit transfer slider 12 that is guided by the head unit transfer guide rail 13 and slidably supported in the Y direction. is composed The head unit transfer slider 12 is feedback-controlled by the head unit transfer linear motor 14 , the head unit transfer position detection unit 15 , and the not-illustrated head unit transfer stage control unit.

The head unit 32 is comprised by mounting the inkjet head part 23 and the alignment camera 21 on the head unit base 22 attached to the slider 12 for head unit transfer. In addition, the inkjet head unit 23 includes a head rotation mechanism 10 mounted on the head unit base 22 via a bracket 11 , and a head bracket 9 below the head rotation mechanism 10 . An inkjet head 8 and the like mounted therebetween are provided. The head rotation mechanism 10 is provided with a head rotation angle detection part, a head rotation drive part, etc. which are not shown in figure. The head rotation mechanism 10 is configured to be precisely positioned at a target rotation angle by a head rotation mechanism control unit (not shown).

In addition, the inkjet head 8 has a plurality of droplet ejection nozzles. The inkjet head 8 is configured such that the inkjet head control unit 100 controls the discharge timing for each droplet discharge nozzle of the inkjet head 8 based on the detection position by the substrate transfer position detection unit 7 . . In addition, a plurality of droplet ejection nozzles of the inkjet head 8 are arranged in a line at a predetermined pitch, for example.

The inkjet head control unit 100 is constituted by a microcomputer that controls the ejection operation of the inkjet head 8 . Specifically, the inkjet head control unit 100 includes, for example, a central processing unit (CPU), a read only memory (ROM), a random access memory (RAM), an input port, an output port, and the like.

In addition, the inkjet head control unit 100 includes a storage unit 110 , a calculation unit 120 , and the like. The memory|storage part 110 memorize|stores the impact position shift characteristic of a droplet at the time of discharging a droplet from the inkjet head 8. As shown in FIG. The calculating part 120 is based on the impact position shift characteristic, the arrangement pitch of the droplet discharge nozzle of the inkjet head 8, and the application|coating target pitch of the application|coating object in the direction orthogonal to a scanning direction, the inkjet head 8 In addition to finding the target rotation angle of , a print pattern corresponding to the target rotation angle is generated. In addition, the said impact position shift characteristic is the impact position from the target position of the droplet discharged from the inkjet head 8 in each of the 1st rotation angle and 2nd rotation angle from which the inkjet head 8 mutually differs. It is saved based on the deviation. Details will be described later.

In addition, an air bearing mechanism is employ|adopted for the board|substrate conveyance stage 30 and the head unit transfer stage 33 of this embodiment. This makes it possible to realize high-precision positioning.

(Operation of inkjet printing device)

Next, the operation of the inkjet printing apparatus 40 having the above configuration will be described with reference to FIGS. 2 to 13 .

2 : is a top view which shows the board|substrate 1 of the application|coating object which concerns on an example of this embodiment.

As shown in FIG. 2, the board|substrate 1 has the base material 1a, the alignment mark 1b formed on the base material 1a, the bank 1c, the application|coating target part 1d, and the test print. It has an area 1e and the like. The alignment mark 1b is formed in the four corners on the base material 1a. The bank 1c serves as a dike so that the ink printed on the application target portion 1d does not overflow. The application target portions 1d are surrounded by the banks 1c and are arranged at a constant pitch. The test print area 1e has the impact measurement area 1f, and is formed in order to measure the impact position of a droplet.

The impact measurement area 1f is formed in the test printing area 1e. The impact measurement area 1f is formed on the extension line of the application|coating target part 1d at the same pitch as the application|coating target part 1d.

In addition, the application|coating target part 1d is an area which comprises the pixel of a display panel. The application|coating target part 1d is comprised so that an impacted droplet may wet-spread. On the other hand, the impact measurement area 1f is comprised so that it may have liquid repellency. Thereby, the droplet which landed on the impact measurement area 1f stays in circular shape. Therefore, the position with respect to the center of the circle of the impact measurement area 1f can be measured with high precision by imaging the position of the droplet which landed with the alignment camera 21, and processing it by the image processing part which is not shown in figure.

The substrate 1 further includes an application area 1g. The application area 1g is comprised from the area which gave liquid repellency similarly to the impact measurement area 1f. In addition, the application area 1g is formed as an area used in order to measure the approximate impact position of a droplet, when a droplet does not enter in the circle of the impact measurement area 1f.

(When the substrate 1 and the inkjet head 8 do not move relative to each other)

Next, when the substrate 1 and the inkjet head 8 do not move relative to each other, the position of the droplet ejection nozzle of the inkjet head 8 and the droplet ejected from the droplet ejection nozzle reach the substrate 1 The relationship of an impact position is demonstrated using FIGS. 3A-4B.

FIG. 3A is a plan view illustrating an impact position shift due to the discharge angle wall of the droplet discharged from the inkjet head 8 . Fig. 3B is a side view of Fig. 3A;

4 : A is a top view explaining the impact position shift by the discharge angle wall of a droplet when the rotation angle of the inkjet head 8 is 0 (zero) degree. It is a top view explaining the impact position shift by the discharge angle wall of a droplet when the rotation angle of an inkjet head is (phi) degree.

Here, the inkjet head 8 shown in Fig. 3A has four droplet ejection nozzles indicated by dotted circles. And let the hole positions of the droplet discharge nozzle be n ₁ , n ₂ , n ₃ , and n ₄ . In general, each of the droplet discharge nozzles has a habit (corresponding to the discharge angle wall as described above) in which the discharge direction differs depending on the processing precision at the time of manufacture or the like. Therefore, as shown in Figure 3b, the landing position when deposited on the surface of the ink-jet head 8 droplet ejection away from the nozzle face G as off the substrate 1 of, landing indicated by a circle of solid line position (P ₁ , P ₂ , P ₃ , P ₄ ). That is, the impact positions P ₁ , P ₂ , P ₃ , and P ₄ reach different positions just below _{the hole positions n 1} , n ₂ , n ₃ , and n ₄ of the droplet discharge nozzle. Hereinafter, the position shift amount is called the "impact position shift" by the discharge angle wall.

Incidentally, the displacement of the impact position due to the discharge angle wall from each droplet discharge nozzle is determined by the shape precision of the hole of the droplet discharge nozzle, the surface state of the periphery of the droplet discharge nozzle, and the like. That is, the discharge angle wall from the droplet discharge nozzle becomes a fixed habit in the mounted inkjet head 8 . Therefore, compared to when the rotation angle of the inkjet head 8 shown in FIG. 4A is 0 degrees, even when the rotation angle of the inkjet head 8 shown in FIG. 4B is rotated by φ degrees, the hole position of the droplet discharge nozzle of the head With respect to (n ₁ , n ₂ , n ₃ , n ₄ ), the impact positions P ₁ , P ₂ , P ₃ , P ₄ shift in the same direction within the inkjet head 8 . That is, Fig. 4B, which is a plan view when the inkjet head 8 is rotated by phi degrees, is a position in which Fig. 4A is rotated by phi degrees as it is. In addition, the rotation center O indicated by a black circle in FIGS. 4A and 4B corresponds to the rotation axis of the inkjet head 8 .

(When the substrate 1 and the inkjet head 8 move relative to each other)

Next, the impact position at the time of discharging a droplet toward the board|substrate 1 from the droplet discharge nozzle of the inkjet head 8 in the board|substrate 1 traveling at constant speed V with respect to the inkjet head 8. will be described with reference to FIGS. 5A to 6B.

Fig. 5A is a plan view for explaining the displacement of the impact position of the droplet discharged from the inkjet head 8 when the application object is still. Fig. 5B is a side view of Fig. 5A. 6A is a plan view for explaining the displacement of the impact position of the droplet discharged from the inkjet head when the application target is traveling at the speed V. FIG. Fig. 6B is a side view of Fig. 6A.

As shown in Figure 5a, the landing position of landing have a substrate (1) discharged from the liquid discharge nozzles of the hole position (n ₁₎ of the inkjet head 8 to the state in which that terminating solution, a substrate (1) P _{set to 1} . In addition, the position shift amount of the impact position P _{1 with respect to the hole position n 1} corresponds to the impact position shift by the discharge angle wall demonstrated with FIG. 4A and FIG. 4B. On the other hand, the droplet discharged from the droplet discharge nozzle of the _{hole position n 1} to the board|substrate 1 traveling at the constant speed V flies with speed. Therefore, it takes time until the droplet reaches the substrate 1 . When that time is ?t, during that time, the substrate 1 travels by ?txV. Therefore, as shown in Fig. 6a, landing position (Q ₁₎ of the enemy on the substrate (1) is liquid and is shifted with respect to the landing position (P ₁₎ at the time sikyeoteul deposited a substrate (1) stationary.

In addition, in reality, the droplet flows under the influence of air resistance and deceleration while flying toward the substrate 1 or the influence of wind generated by the traveling of the substrate 1 , so that the droplet flows more , resulting in a complex misalignment. _{Hereinafter, impact position shift ((DELTA)X1v} ) of the traveling direction which generate|occur|produces by traveling of this board|substrate 1 is called "impact position shift" by traveling. That is, since the impact position shift by this running is an impact position shift accompanying running of the board|substrate 1, it is a position shift which generate|occur|produces in a running direction basically. Therefore, unlike the positional shift due to the discharge angle wall of the inkjet head 8 , even when the inkjet head 8 is rotated, it does not rotate with the rotation of the inkjet head 8 .

As described above, when the substrate 1 is stopped, _{the impact position on the substrate 1} of the droplet discharged from the hole position n 1 of the droplet discharge nozzle is only the impact position shift due to the discharge angle wall. It becomes the impact position P _{1 .} On the other hand, the substrate 1 in this case, which is traveling at a speed V, deposited by the landing position shifted by the ejection angle of the wall to add, with respect to the landing position (P _1), running in the running direction of the substrate 1 where It will land at the position where the deviation (ΔX1v) was added.

Next, a method of printing a droplet on the application target portion 1d of the substrate 1 will be described by dividing it into 1) and 2) below.

1) First, the alignment method of the board|substrate 1 is demonstrated.

First, the board|substrate 1 is adsorbed and fixed on the board|substrate adsorption|suction table 2, and the board|substrate conveyance stage 30 and the head unit transfer stage 33 are moved.

Next, the alignment marks 1b of the four corners of the substrate 1 are moved under the alignment camera 21 mounted on the head unit 32 .

Next, the alignment mark 1b is imaged with the alignment camera 21, and the position of the alignment mark 1b is measured by the image recognition part which is not shown in figure. On the other hand, based on the detection position by the substrate transfer position detection unit 7 at that time and the detection position by the head unit transfer position detection unit 15, the traveling direction of the substrate transfer stage 30 and the , The substrate rotation mechanism 3 is driven and adjusted so that the direction of the application target portion 1d of the substrate 1 becomes parallel.

2) Next, a method for adjusting the position of the droplet discharge nozzle and the application target portion 1d of the substrate 1 will be described with reference to FIG. 7 .

Fig. 7 is a plan view for explaining the impact position of the ejected droplets when the coating target travels at the speed V at the first rotation angle (here, the rotation angle 0 (zero) degree) of the inkjet head. .

In FIG. 7 , dotted circles in the drawing indicate hole positions n ₁ , n ₂ , n ₃ , and n ₄ of the droplet discharge nozzles in the inkjet head 8 . Then, the source of the solid line, by the ejection angle wall the liquid droplets discharged from the liquid discharge nozzle is deviated a position when it reaches the substrate 1 shows a landing position _{(P 1, P 2, P} 3, P 4). In addition, the circle of the double solid line of FIG. 7 adds the impact position shift by travel which generate|occur|produces by the travel of the board|substrate 1 with respect to _{impact position P 1} , P ₂ , P ₃ , P _{4 further.} landing position _{(Q 1, Q 2, Q} 3, Q 4) represents the.

In Fig. 7, the rotation axis of the inkjet head 8 is indicated by a black circle so that the droplet pitch in the Y direction of the _{inkjet head 8 coincides with the application target pitch W 0 of the application target portion 1d.} (O) The rotation angle of the circumference is positioned at 0 degrees.

(Calculation of impact position shift characteristic)

Next, about the method of calculating the characteristic (hereinafter, abbreviated as "impact position shift characteristic") of the impact position shift which generate|occur|produces when the inkjet printing apparatus 40 discharges a droplet from the inkjet head 8, FIG. 8A The description will be made with reference to FIGS. 8E.

Fig. 8A is the state of Fig. 7, that is, when the application target travels at the speed V and when the rotation angle of the inkjet head is 0 degrees, the impact position of the ejected droplet and the application target portion 1d of the application object It is a plan view explaining the amount of position shift in the Y direction.

In addition, in FIG. 8A, _{the Y direction position of the droplet impact position (Q 1} , Q ₂ , Q ₃ , Q ₄ ) and the distance in the Y direction of the central axis of the application target part 1d are respectively ΔY ₁₀ , It is represented by _{ΔY 20} , ΔY ₃₀ , and ΔY _{40 .}

That is, with respect to the alignment between the inkjet head 8 and the substrate 1 in the Y direction, the alignment is made so that the total errors of _{ΔY 10} , ΔY ₂₀ , ΔY ₃₀ , and ΔY _{40 are minimized.}

8B is the state of FIG. 7, that is, the case where the coating target travels at the speed V, and when the rotation angle of the inkjet head 8 is 0 degrees, the impact position of the ejected droplet and the Y-axis X direction It is a floor plan that describes the distance.

There is also in 8b, the droplet landing position _{(Q 1, Q 2, Q} 3, Q 4) represents the distance in the X direction with the Y-axis, respectively, X _1S0, X _2S0, X _3S0, X _4S0 .

In addition, Figure 8c shows an landing position in the case of correcting the ejection timing corresponding to the distance in the X-direction X _{1S0, 2S0} X, X _{3S0, 4S0} X. That is, according to the correction|amendment which adjusts the discharge timing, as shown in FIG. 8C, the droplet is discharged from all the droplet discharge nozzles, and the impact position which reached the board|substrate 1 was substantially aligned on the Y-axis (including the Y-axis). can be printed. Hereinafter, this print pattern is called "first print pattern."

And FIG. 8D has shown the impact position of a droplet at the time of printing on the impact measurement area 1f of the board|substrate 1, and the application|coating target part 1d in the said state. Hereinafter, this printing is called "first printing step". Here, in FIG. 8D, the droplet in the application|coating target part 1d is displayed with double circles. However, in reality, the application target portion 1d has hydrophilicity. Therefore, the droplet which landed on the application|coating target part 1d wet-diffusion within the application|coating target part 1d. On the other hand, the impact measurement area 1f has liquid repellency. Therefore, as shown in FIG. 8D, the droplet which impacted the impact measurement area 1f turns into a circular shape in the circle which surrounds the impact measurement area 1f.

In addition, FIG. 8E is an enlarged view of part A in FIG. 8D which is shown together with the top view of FIG. 8D.

In the said state, the impact measurement area 1f of FIG. 8E is imaged with the alignment camera 21, and an image process is performed. _{And Y-direction displacement ΔY i0} , and X-direction displacement ΔX _i0 (i) of the circle of the impact measurement area 1f of the application target pitch W _{0 and the circle of the droplet in the impact measurement area 1f} = 1, 2, 3, 4). Thereby, the impact position shift of a droplet can be measured accurately. Hereinafter, this measurement is called "a 1st impact position shift detection step."

_{As a result, from the measurement results ΔX i0} and ΔY _i0 of the impact position shift of the droplet in the impact measurement area 1f described above, _{and the correction amount X iS0} shifted by the correction of the discharge timing of FIG. 8C , the correction of the ejection timing is performed The impact position in the case of not doing it is computable accurately. Hereinafter, this calculation step is called "a 1st impact position calculation step". And let the calculated impact position data be "1st impact position data."

Next, in the case where the application target pitch of the application target portion 1d is _{W 1} which is smaller than _{W 0} , the inkjet head 8 is rotated around the rotational center O, which is the rotation axis, θ so _{that the droplet pitch coincides with W 1 .} The case of applying by rotating the figure will be described with reference to Figs. 9A to 9E.

Fig. 9A shows the impact position of the ejected droplets when the inkjet head 8 is rotated at the second rotation angle (here, the rotation angle, θ degree) in the case where the application object travels at the speed V, and the application It is a top view explaining the positional shift amount of the Y-direction of the application|coating target part 1d of an object. In addition, in FIG. 9A, _{the Y direction position of the droplet impact position (Q 1} , Q ₂ , Q ₃ , Q ₄ ) and the Y direction distance of the central axis of the application target part 1d are respectively ΔY _1θ , It is represented by _{ΔY 2θ} , ΔY _3θ , and ΔY _{4θ .}

Then, the alignment according to the alignment in the Y direction of the inkjet head 8, and a substrate (1), _1θ ΔY, ΔY _{2θ, 3θ} ΔY, ΔY is the total error of _4θ, is minimized.

Fig. 9B shows the impact position of the ejected droplets when the rotation angle of the inkjet head 8 is θ degrees in the state of Fig. 9A, that is, when the application object travels at the speed V, and the distance in the X direction of the Y axis. It is a plan view that describes

In Figure 9b, shows a droplet landing position _{(Q 1, Q 2, Q} 3, Q 4) of the distance in the X direction of the Y axis, respectively, X _1Sθ, X _2Sθ, X _3Sθ, X _4Sθ .

Moreover, FIG. 9C has shown the impact position of a droplet at the time of correcting the discharge timing corresponding to _{the distance (X 1Sθ} , X _2Sθ , X _3Sθ , X _{4Sθ ) in the X direction shown in FIG. 9B .} That is, as shown in Fig. 9C, by adjusting the ejection timing, the impact positions of droplets ejected from all droplet ejection nozzles and reached the substrate 1 can be almost aligned on the Y-axis (including on the Y-axis). . Hereinafter, this print pattern is referred to as a "second print pattern."

9D is the state of FIG. 9C, and has shown the impact position of the droplet in the case of printing on the impact measurement area 1f of the board|substrate 1, and the application|coating target part 1d. Hereinafter, this printing is referred to as "second printing step". In addition, in FIG. 9D, the droplet in the application|coating target part 1d is displayed with a double circle. However, in reality, the application target portion 1d has hydrophilicity. Therefore, the droplet which reached the application|coating target part 1d will wet-diffusion. On the other hand, the impact measurement area 1f has liquid repellency. Therefore, the droplet which reached the impact measurement area 1f turns into a circular shape in the circle which surrounds the impact measurement area 1f, as FIG. 9D shows.

In addition, FIG. 9E is an enlarged view of part A in FIG. 9D which is shown together with the top view of FIG. 9D.

In the said state, the impact measurement area 1f of FIG. 9E is imaged with the alignment camera 21, and an image process is performed. _{And Y-direction displacement ΔY iθ} of the circle of the impact measurement area 1f of the application target pitch W ₁ and the circle of the droplet in the impact measurement area 1f, and the X-direction displacement ΔX _iθ (i) = 1, 2, 3, 4). Thereby, the impact position shift of a droplet can be measured accurately. Hereinafter, this measurement is called "a 2nd impact position shift detection step."

As a result, from the measurement result of the impact position shift of the droplet in the said impact measurement area 1f, ΔX _iθ and ΔY _{iθ, and the correction amount X iSθ} shifted by the correction of the discharge timing of FIG. 9C , the discharge timing is corrected The impact position in the case of not doing this is computable accurately. Hereinafter, this calculation step is called "a 2nd impact position calculation step". And let the calculated impact position data be "2nd impact position data."

In addition, in this embodiment, the relative movement speed of the inkjet head 8 and the board|substrate 1 in the 1st printing step mentioned above, and the inkjet head 8 and the board|substrate 1 in the 2nd printing step. The relative movement speed of 1) is set to be the same.

As described above, the coating target pitch of Fig coating shown in 8a target portion (1d) applying the coating target portion (1d) a target pitch that indicates the W ₀ of the substrate and, Figure 9a with respect to W ₁ is a substrate, an ink jet head ( 8) is rotated by θ degrees. Thereby, the application|coating target pitch of a droplet can match the application|coating target pitch of an application|coating target part, and it can print.

At this time, the impact position of each droplet is accurately measured with respect to the application|coating target pitch of the different application|coating target part 1d.

And based on the measurement result of the impact position of the droplet on the said two types of board|substrates 1, with respect to the board|substrate of arbitrary application|coating target pitch, the optimal rotation angle of the inkjet head 8 at which impact shift becomes the minimum is determined. Calculate. Thereby, a droplet can be apply|coated to an appropriate position with respect to the board|substrate of arbitrary application|coating target pitches, without test printing.

Hereinafter, the method will be described with reference to FIG. 11 .

11 is a diagram illustrating the respective liquids when the rotation angle around the rotation center O of the head is 0 (zero) degrees, and θ degrees from there, with respect to one nozzle in the inkjet head 8. It is a figure which shows the relationship of the enemy's impact position. Here, the X coordinate of the rotation center O of the head is δx, and the Y coordinate is δy. Moreover, let Xa and Y coordinate be Xa and Y coordinate for the impact position when a rotation angle is 0 degree in Q ₀ and Q _{0 , and describe it as Q 0} (Xa, Ya). On the other hand, the impact position at the time of a rotation angle is θ degree Q _θ , _{the X coordinate of Q θ} is Xb, the Y coordinate is Yb, and it is expressed as Q _θ (Xb, Yb). In addition, the displacement in the X direction of the positions, the droplets deposited by the traveling of the substrate (1), as ΔX _V.

That is, in the case of applying to the traveling substrate 1, the displacement of the landing position of the droplet discharged from the inkjet head 8 and impacting the substrate 1 is due to the discharge angle wall when the droplet is discharged from the droplet discharge nozzle. It becomes the value which added the impact position shift by travel of the board|substrate 1 to impact position shift. At this time, as mentioned above, the impact position shift by the discharge angle wall rotates with rotation of the inkjet head 8. On the other hand, the impact position shift by running of the board|substrate 1 is determined by the running direction of the board|substrate 1 irrespective of rotation of the inkjet head 8. _{That is, the impact positions P 0} and P _θ by only the discharge angle wall of the rotation angle of 0 degree and θ degree of the inkjet head 8 are respectively _{X coordinates of P 0} are Xa-ΔX _V , Y coordinates are Ya, The X-coordinate of P _{θ becomes Xb-ΔX V} , and the Y-coordinate becomes Yb.

And impact position P ( _theta ) is corresponded to the position which θ degree rotated around rotation center O which is a head rotation axis at impact position P _0. Therefore, the relationship between the landing position of the point P _θ and a landing position P ₀ that it can be displayed, as shown in accordance with the rotation of the coordinate expression, as described below, the equation (1), equation (2).

Further, according to the above equations (1) and (2), the Y-coordinate δy of the rotation axis of the inkjet head 8 and the positional shift (ΔX _V ) due to the traveling of the substrate 1 are expressed by the equation (3), It can be obtained as in Equation (4). In addition, it is necessary to measure separately about the X-axis coordinate δx of the rotation axis of the inkjet head 8 . The measurement method will be described later.

As described above, the X-coordinate δx of the center of rotation O of the inkjet head 8 is previously obtained. And, in the printing method while traveling the substrate 1 at the speed V, the rotation angle of the head of the inkjet head 8 is 0 degree (first rotation angle) and θ degree (second rotation angle). landing position Q ₀ (Xa, Ya) of the two kinds of angles (landing position data of the Fig. 1) to measure the _θ Q (Xb, Yb) (landing position data of a second). Due to the foregoing, it can be obtained, a droplet landing position shift (ΔX _V) according to the traveling of the substrate (1). In addition, when the determined landing position shift (ΔX _V), can be obtained the landing position shift due to the discharge angle of the wall. Hereinafter, this calculation step is called "an impact position shift characteristic calculation step."

The data related to the impact position shift characteristic calculated by the said method is stored in the memory|storage part 110 as data which shows the characteristic characteristic of the inkjet head 8 used.

In addition, when the droplet discharge operation|movement for calculating the impact position shift characteristic prints the application|coating target part 1d, for example, it apply|coats a droplet to the impact measurement area 1f together. And it can implement by measuring the impact position shift of a droplet within the impact measurement area 1f.

(Operation when printing is executed)

The calculating part 120 of the inkjet printing apparatus 40 calculates|requires the target rotation angle of the inkjet head 8 at the time of printing execution using the impact position shift characteristic calculated by the said method. In addition, the calculator 120 generates a print pattern corresponding to the target rotation angle.

In addition, in this embodiment, when a droplet is discharged from each droplet discharge nozzle of the inkjet head 8, the rotation angle at which the positional shift of the application|coating target object in the application|coating target part 1d becomes the smallest at the time of printing execution Let it be the target rotation angle of the inkjet head 8.

Hereinafter, this target rotation angle may be called "optimum rotation angle." In this case, the target rotation angle is set at a rotation angle at which the positional shift of the application target object in the application target portion 1d is equal to or less than the threshold when droplets are ejected from each droplet ejection nozzle of the inkjet head 8. it is preferable

Hereinafter, from the impact position shift characteristic calculated|required above, and the rotation center (O(δx, δy)) of the inkjet head 8, the printing method while traveling the board|substrate 1 at the speed V WHEREIN: Inkjet head 8 The calculation method of the impact position in arbitrary 3rd rotation angle (phi) is demonstrated using FIG. In addition, the landing position shift characteristic, and includes a landing position shift (ΔX _V), and the discharge landing position shift due to the angle of the wall by the driving of the substrate (1).

12 : is a figure explaining the impact position shift of a droplet when the rotation angle of the head of the inkjet head 8 is 0 degree, and when it is (phi) degree.

First, the calculating part 120 reads the data related to the impact position shift characteristic memorize|stored in the memory|storage part 110.

Next, the calculation unit 120 subtracts _{the impact position shift (ΔX V ) due to travel from the X coordinate of the impact position (Q 0} (Xa, Ya)) in which the rotation angle of the inkjet head 8 is 0 degrees . And the calculating part 120 calculates|requires the impact position P ₀ (Xa-ΔX _V , Ya) of the droplet when there is only the discharge angle wall.

Next, the calculating part 120 _{is the impact position P phi} (Xd) of the droplet, when there is only the discharge angle wall which rotated phi also around the rotation center O which is the rotation center of a head around the _{impact position P 0 point.} , Yd)). Then, the operation section 120, the X coordinate of the determined landing position P _φ point, it adds a landing position shift (ΔX _V) according to the traveling of the substrate (1). In this way, it is landing position _{(Q φ (Xe, Ye)} ) according to the rotation angle (φ) is nine. When this is displayed by an formula, _{the coordinates of the impact position P (phi)} point can be represented by Formula (5), Formula (6), and _{the coordinates of the impact position Q (phi)} point can be represented by Formula (7) and Formula (8). Hereafter, the step of calculating the impact position in the 3rd rotation angle phi of this inkjet head 8 is called "an impact position prediction step."

At this time, the calculating part 120 variously changes 3rd rotation angle phi of the inkjet head 8, and calculates the impact position of the droplet in each of some 3rd rotation angle phi. do.

_{Next, the calculating unit 120 obtains the optimum rotation angle φ c} of the inkjet head 8 when the inkjet head 8 discharges droplets from the inkjet head 8 with respect to the application target portion 1d of the application object. Specifically, the calculating unit 120 is configured to operate on the basis of the arrangement pitch of the droplet discharge nozzles of the inkjet head 8 and the application target pitch of the application target portion 1d of the application object in a direction orthogonal to the scanning direction, Find the optimal rotation angle (φ _c ). Specifically, the calculation unit 120 first, for example, a plurality of third rotation angles of the inkjet head 8, each of the phi degrees, for the impact position of the droplet with respect to the application target portion 1d Calculate the relevant evaluation value. And on the basis of the calculated evaluation value, the calculating part 120 calculates|requires the optimal rotation angle (phi _c ).

In addition, in the said Formula (7) and Formula (8), the calculation formula of the impact position of one droplet discharge nozzle in the rotation angle of the inkjet head 8, and (phi) degree was shown.

Below, the calculation formula of the impact position of the droplet discharge nozzle is shown with respect to the case of the inkjet head 8 which provided the some droplet discharge nozzle.

That is, when the rotation angle of the inkjet head 8 of the i-th droplet discharge nozzle is 0 degrees (first rotation angle), the coordinates of the impact position are (X _ia , Y _ia ), and the rotation angle is θ degrees (second rotation angle). angle of rotation) the landing position coordinates (X _{ib, ib} Y in), and the displacement amount by the traveling of the i-th nozzle by ΔX _iv. In addition, when the impact position coordinate in rotation angle phi (3rd rotation angle) is made into (X _ie , Y _ie ), the value of the impact position coordinate is the following Formula (9), Formula (10), can be displayed together.

_{Here, the position shift amount (ΔX iv} ) due to running of the i-th nozzle can be expressed by Formula (11).

Then, if the Y-coordinate of the application target portion of the i-th droplet discharge nozzle is Y _ti , and the Y-coordinate of the impact position of the i-th droplet discharge nozzle is Y _ie , the difference (ΔY _iφ ) is expressed by Equation (12) can do.

Here, FIGS. 10A to 10E show the relationship between _{the difference ΔY iφ} and the position shift amount ΔX _{iv .} Further, i in FIGS. 10A to 10E denotes four droplet ejection nozzles 1, 2, 3, and 4 .

_{Then, in order to obtain the optimum rotation angle φ c} of the inkjet head 8 , the calculation unit 120 , as shown in Equation (13), is an average of the sum of squares _{of the Y-direction position shifts ΔY iφ of all the droplet ejection nozzles.} (Δt) is calculated as an evaluation value.

Next, the calculating unit 120 changes the rotation angle φ, calculates the average sum of squares Δt at each rotation angle φ, and the rotation angle φ at which the average sum of squares Δt becomes the minimum. ) to find the value of Then, the rotation angle phi at which the average sum of squares Δt is the minimum becomes the optimum rotation angle phi _c of the inkjet head 8 .

In addition, the calculation unit 120 calculates the offset amount Δy in the Y direction by equation (14). The offset amount Δy is reflected in printing by offsetting the calculated offset amount Δy when the substrate 1 and the inkjet head 8 are aligned.

And the calculating part 120 calculates the impact position coordinate ( _Xieφc ) of the X direction of each droplet discharge nozzle with Formula (15) with _respect to X direction, and correct|amends the discharge timing of the quantity corresponded to -Xieφc. do. Hereinafter, the print pattern corrected for the ejection timing is referred to as an "optimal print pattern". In addition, the generation step is referred to as an "optimal print pattern generation step".

In addition, when the rotation angle of the inkjet head 8 is set to the optimal rotation angle (phi _c ), the Y-direction impact position coordinate (Y _ie phi c ) of each droplet discharge nozzle is computed by Formula (16). In addition, the position shift (ΔY _ieφc ) in the Y direction from the target coordinate is calculated by Expression (17). And the Y coordinate of the impact position at the time of considering the offset of a Y direction turns into _{Yiephic -(DELTA)y.}

That is, the inkjet head control unit 100 of the inkjet printing apparatus 40 positions the inkjet head 8 at the optimum rotation angle φ _c calculated above and the offset amount Δy in the Y direction, , print according to the above optimal printing pattern. Thereby, the inkjet printing apparatus 40 can discharge a droplet so that the positional shift with respect to the application|coating target part 1d may become the smallest.

In addition, at the time of printing, in the inkjet printing apparatus 40, the relative movement speed of the inkjet head 8 and the board|substrate 1 is the same as the speed in the said 1st printing step and 2nd printing step, so that the substrate transfer stage 30 is controlled.

The above state is shown in Figs. 10B to 10E.

10B shows the impact positions of droplet ejection nozzles No. 1, 2, 3, and 4, and the X direction of the Y axis when the head rotation angle of the inkjet head 8 is set to the optimum rotation angle φ _{c obtained above.} It is a drawing showing the distance.

It is a figure which shows the impact position at the time of correct|amending the impact position of each droplet discharge nozzle of FIG. 10B, and the discharge timing for the X direction distance of a Y-axis. That is, as shown in FIG. 10C, when the discharge timing is corrected by the positive opposite direction calculated by the formula (15), -X _ie?c , the impact position of each droplet discharge nozzle is superimposed on the Y-axis.

And, FIG. 10D shows the figure which apply|coated the droplet on the board|substrate 1 in the said state.

As shown in FIG. 10D , by setting the rotation angle of the inkjet head 8 to the optimum rotation angle φ _c , the positional shift between the impact position of each droplet discharge nozzle and the application target position is minimized.

In addition, FIG. 10E is an enlarged view of the impact position in the impact measurement area 1f at the time of actually apply|coating shown together with the top view of FIG. 10D. In addition, in FIG. 10E, the impact position in the impact measurement area of the droplet discharged from the 3rd and 4th droplet discharge nozzle is shown. From FIG. 10E, it turns out that the position shift amount (( _{DELTA )X3φc} , ΔX4φc) of the droplet which actually landed with the target position of the X direction has become substantially the target position.

Moreover, when it is desired to further adjust the said position shift amounts (( _{DELTA )X3φc} , ΔX4φc), the discharge timing for this position shift amount is corrected. Thereby, it is also possible to further reduce the position shift amounts (ΔX _3φc , ΔX _{4φc ).}

(About how to obtain the coordinates of the rotation center of the inkjet head)

Next, a method of obtaining the coordinates of the rotation center O(δx, δy) of the inkjet head 8 will be described with reference to FIG. 13 .

13 : is a top view explaining the impact position of a droplet before and behind (theta) degree rotation of the inkjet head 8 in the case where an application|coating target object is still.

In this case, since the object to be printed is stationary, displacement due to travel does not occur and only displacement due to the discharge angle wall from the droplet discharge nozzle occurs. That is, if the impact position before rotation is P _0V0 (Xa _V0 , Ya _V0 ) and the impact position after the θ degree rotation is P _θV0 (Xb _V0 , Yb _V0 ), the impact position P _θV0 will set the impact position P _0V0 as the rotation center ( O) circumferentially, θ also corresponds to the rotated position. Therefore, the relationship between the coordinates can be expressed by the following formulas (18) and (19).

Then, when the coordinates (δx, δy) of the rotation center O of the inkjet head 8 are obtained from the above equations (18) and (19), the equations (20) and (21) are obtained.

In addition, the operation of specifying the coordinates of the rotation center O of the inkjet head 8 needs to be performed only once first, when the inkjet head 8 is mounted on the head rotation mechanism 10 . In the above operation, it is not necessary to use all the droplet ejection nozzles, for example, it is preferable to select and perform two droplet ejection nozzles that are separated from each other in the vicinity of both ends of the inkjet head 8 and have high ejection reproducibility. .

As described above, according to the inkjet printing apparatus 40 according to the present embodiment, the inkjet head 8 first rotates from the inkjet head 8 at each of the mutually different first and second rotation angles. Based on the impact position shift from the target position of the discharged liquid droplet, the impact position shift characteristic is computed. And, based on the calculated impact position shift characteristic, it is to set and print the optimal head rotation amount of the inkjet head 8 without test printing with respect to the application|coating target part 1d of arbitrary application|coating target pitches. it becomes possible

The above method can be carried out by simultaneously applying a droplet to the impact measurement area 1f and measuring the impact position shift in the impact measurement area 1f when the actual application target portion 1d is printed. . Thus, during the production of the substrate (1) of the substrate 1, and the coating target pitch (W ₁₎ of the coating and the target pitch (W _0), and measuring the landing position shift. And based on the measurement result of the impact position shift, with respect to the board|substrate 1 of an arbitrary application|coating target pitch, the rotation angle of the droplet discharge head of the inkjet head 8 is set so that an impact position shift may become the minimum. As a result, according to the inkjet printing apparatus 40 according to the present embodiment, even in high-definition printing in which it is necessary to consider even the displacement of the impact position due to the discharge angle wall of the droplet discharge nozzle, the step of lowering the operation rate such as test printing is minimized. It is possible to perform high-precision printing while suppressing the

As mentioned above, according to the inkjet printing apparatus 40 which concerns on this embodiment, without using a special board|substrate for measuring an impact wall, it can measure the impact wall of a droplet with an actual production board|substrate. can And based on the measurement result, with respect to the board|substrate of arbitrary application|coating target pitches, a droplet can be apply|coated to a board|substrate accurately, without performing test printing. As a result, the operation rate is high and high-definition display panel printing is attained.

Claims (7)

An inkjet printing method for applying ink on the application object by discharging droplets from the inkjet head while scanning the inkjet head relative to the application object,
In each of the first rotational angle and the second rotational angle different from each other in the inkjet head, the impact positional shift characteristic obtained based on the impact positional shift from the target position of the droplet discharged from the inkjet head is stored. 1st step of reading the data related to the said impact position shift characteristic from a memory|storage part;
The target rotation angle of the inkjet head is obtained based on the impact position shift characteristic, the arrangement pitch of the droplet ejection nozzles of the inkjet head, and the application target pitch of the application object in a direction orthogonal to the scanning direction. , a second step of generating a print pattern corresponding to the target rotation angle;
a third step of controlling the inkjet head based on the target rotation angle and the printing pattern to discharge droplets to the application target portion on the application object
Including, inkjet printing method. The method according to claim 1,
The said impact position shift characteristic contains the amount of impact position shift by the discharge angle wall of the droplet discharge nozzle of the said inkjet head, and the amount of impact position shift accompanying scanning of the said inkjet head, The inkjet printing method. The method according to claim 1 or 2,
a fourth step of calculating an offset amount in a direction orthogonal to a scanning direction of the inkjet head for positioning the inkjet head to the application target portion when the inkjet head is at the target rotation angle do,
In the third step, based on the target rotation angle, the printing pattern, and the offset amount, the inkjet head is controlled to discharge droplets to the application target portion. 4. The method according to any one of claims 1 to 3,
The said impact position shift characteristic is calculated|required by the steps shown to the following A)-E) and memorize|stored in the said memory|storage part,
A) positioning the inkjet head at the first rotation angle with the normal direction of the application surface as a rotation axis, and discharging droplets in a first print pattern;
B) detecting an impact position shift from the target position indicated by the first print pattern of the ejected droplet in the step A);
C) positioning the inkjet head at the second rotation angle and discharging droplets in a second printing pattern;
D) detecting an impact position shift from the target position indicated by the second print pattern of the ejected droplet in the step C);
E) based on the impact position shift detected in the step B), the impact position shift detected in the step D), and the coordinates of the rotation axis of the inkjet head, calculating the impact position shift characteristic comprising, an inkjet printing method. 5. The method according to claim 4,
In the third step, the relative movement speed of the inkjet head and the application object is the relative movement speed of the inkjet head and the application object in the step A), and in the step C) and discharging droplets from the inkjet head to the application target portion under the same conditions as the relative movement speed of the inkjet head and the application object. An inkjet printing apparatus for applying ink on the application object by discharging droplets from the inkjet head while scanning the inkjet head relative to the application object,
In each of the first rotational angle and the second rotational angle at which the inkjet head is different from each other, the impact positional shift characteristic obtained based on the impact positional shift from the target position of the droplet ejected from the inkjet head is stored; wealth,
The target rotation angle of the inkjet head is obtained based on the impact position shift characteristic, the arrangement pitch of the droplet ejection nozzles of the inkjet head, and the application target pitch of the application object in a direction orthogonal to the scanning direction. , a calculating unit for generating a print pattern corresponding to the target rotation angle,
Controlling the inkjet head based on the target rotation angle and the printing pattern to discharge droplets to the application target portion on the application object;
Inkjet printing device. 7. The method of claim 6,
a substrate adsorption table for placing a substrate corresponding to the application object;
a substrate rotation mechanism for rotatably supporting a lower portion of the substrate adsorption table;
a substrate transfer stage for transferring the substrate rotating mechanism and the substrate adsorption table;
a substrate transfer position detection unit for detecting a substrate transfer position of the substrate transfer stage;
the inkjet head disposed on the substrate to face the substrate;
a head rotation mechanism disposed above the inkjet head and rotatably supporting the inkjet head with a direction normal to the plane of the substrate as an axis;
and a head transfer stage for transferring the inkjet head and the head rotation mechanism in a direction orthogonal to a transfer direction of the substrate transfer stage and a direction of a rotation axis.

Images