TW202132124A - Inkjet printing method and inkjet printing device for matching a landing pitch of droplets with a coating target pitch of a coating target portion with high precision - Google Patents

Abstract

The invention includes: a first step for reading data of landing position deviation characteristics of a landing position from a memory section that memorizes landing position deviation characteristics, wherein the landing position deviation characteristics is calculated according to landing position deviation measured from a target position for a liquid droplet ejected from an inkjet head in each angle of a first rotation angle and a second rotation angle that are different from each other; and a second step for calculating a target rotation angle for the inkjet head according to the landing position deviation characteristics, an arrangement pitch of droplet ejection nozzles of the inkjet head, and a coating target pitch of a coating object in a direction orthogonal to a scanning direction, and generating a printing pattern corresponding to the target rotation angle. As such, it is able to provide an inkjet printing method that matches the landing pitch of droplets with the coating target pitch of a coating target portion with high precision.

Description

Inkjet printing method and inkjet printing device

The invention relates to an inkjet printing device and an inkjet printing method using the device, and in particular to a method for adjusting the coating pitch of an inkjet head.

In recent years, methods for manufacturing components using inkjet printing devices are attracting attention. The inkjet printing apparatus has a plurality of nozzles that discharge liquid droplets, and discharges liquid 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 can apply droplets to the application target portion of the printing object. As the printing target, there is a printing target represented by a display element, which is a coating target portion in which the printing target is arranged at a constant pitch.

The above-mentioned inkjet printing apparatus is an inkjet head in which a plurality of nozzles are arranged at a constant pitch, and is rotated around a rotation axis in the normal direction of the surface of the object to be printed. In this way, a method of coating the dropped droplets with the pitch of the deposited droplets matching the pitch of the coating target portion of the coating object is disclosed in, for example, Japanese Patent Application Publication No. 2001-108820 (hereinafter referred to as "Patent Documents 1").

The conventional method disclosed in Patent Document 1 will be described using 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 nozzle of the inkjet head. 15 is a diagram showing a conventional operation flow for adjusting the pitch of the application target portion and the pitch of the droplets ejected from the inkjet head and landed on the substrate.

14A and 14B illustrate the inkjet head 108, the droplet ejection nozzle 117 of the inkjet head 108, the substrate 119, the coating target portion 101 on the substrate 119, and the droplets that have landed on the coating target portion 101 118 and so on.

FIG 14A shows a target coated with the coating object portion 101 of the spacing W ₁ 117 of the droplet ejection nozzle pitch L equal to each other. On the other hand, FIG. 14B shows _{a case where the application target pitch W 2} of the application target portion 101 is smaller than the pitch L of the droplet ejection nozzle 117.

As shown in FIGS. 14A and 14B, the inkjet head 108 and the substrate 119 are configured such that, while relatively moving in the X direction as shown in the figure, the droplet ejection nozzle 117 ejects droplets to the coating target portion. 101 Coating droplets. At this time, the coating object is coated target portion 101 of the nozzle pitch of 117 L W ₂ smaller than the droplet discharged, 14B, is configured to: cause the ink jet head 108 rotational angle [theta], In this way, the pitch in the Y direction of the droplet ejection nozzle 117 is matched to the application target pitch W ₂ of the application target portion 101.

15, while explaining in the above-mentioned conventional method, the Y-direction pitch of the droplets 118 discharged from the droplet discharge nozzle 117 and landed on the substrate 119 and the pitch of the coating target portion 101 of the substrate 119 are performed. Matching actions.

In addition, as shown in FIG. 15, the above-mentioned operation is composed of 10 steps from step S1 to step S10.

Specifically, the "pattern for drawing adjustment" in step S1 is a step of applying a test pattern for measuring the droplet pitch, and the "input of the drawn pattern by a sensor" in step S2 is to transfer the test pattern with a camera or the like. Import steps. In addition, the "dot cutting process" in step S3 is a step for cutting out the droplet portion from the data imported in step S2, and the "dot barycentric calculation process" in step S4 is from the data imported in step S3. The step of calculating the center of gravity of the droplet from the extracted droplet data. In addition, the "R-spacing calculation, G-spacing calculation, and B-spacing calculation" in step S5 is to calculate each of R, G, and B from the position of the center of gravity of each droplet of R, G, and B obtained in step S4. The step of the drop point pitch. In addition, the "calculation of the distance between RGs and the calculation of the distance between GBs" in step S6 calculates the distance between the RGs from the respective positions of the centers of gravity of the R droplets, G droplets, and B droplets extracted in step S4. Steps for the distance between the drop points and the GB between the drop points. The "each RGB pitch has become a predetermined distance?" in step S7 is a step for determining whether the drop point pitch of each droplet of R, G, and B calculated in step S5 has become the target distance. "Has the inter-RG pitch and the inter-GB pitch become the predetermined distance?" in step S8 is a step of determining whether the inter-RG landing point pitch and the inter-GB landing point pitch calculated in step S6 have become the target distance. Step S9 "Adjust the Y-axis of the drawing head" is the step S8, when the distance between RG and GB is not the target distance, the drawing head is moved in the Y direction to perform position adjustment. step. In addition, "adjusting the θ axis of the drawing head" in step S10 is a step for adjusting the θ rotation of the drawing head when the pitch of each RGB point has not reached the target distance in step S7.

That is, the conventional method is the following method: in step S1, a test pattern is printed, and in step S2 to step S4, the drop position of the test pattern is detected. In addition, in step S5, the respective drop-point pitches of R, G, and B are calculated, and in step S7, it is determined whether the drop-point pitch has reached the target value. In addition, when the dot pitch does not meet the target value, in step S10, the θ rotation adjustment of the drawing head is performed, and after that, the test printing in step S1 is restarted again. Furthermore, after all the drop point pitches of R, G, and B meet the target value, next, in step S8, it is determined whether the drop point pitch between RGs and the drop point pitch between GBs calculated in step S6 have been Meet the target value. In addition, when the drop point pitch between RGs and GBs does not meet the target value, the Y-axis adjustment is performed in step S9, and the test printing of step S1 is restarted again.

As described above, in the conventional method, whenever the pitch of the coating target portion is changed, test printing is performed to measure the pitch of the droplets. In addition, it is necessary to further fine-tune the rotation angle based on the measured results, and repeat the approach of the rotation angle and the Y direction until it reaches the threshold of the target. Even with this method, when the fineness is low and the target threshold is large, the adjustment can be completed through the above-mentioned 1 to 2 approximation processing, so it is unlikely to be a problem.

However, in recent years, under the background of increasing expectations for high-definition display elements, it is necessary to reduce the pitch of the application target portions. Therefore, it is necessary to precisely align the pitch of the droplets discharged from the nozzle. In the case of coating on a high-definition display element, the droplet ejection angle tendency of the ejected liquid droplets from each nozzle causes a slight displacement of the landing position, or is accompanied by the relative difference between the coating object and the inkjet head The offset of the moving drop point will greatly affect the accuracy of the coating position.

Therefore, in the conventional method, in the case of coating on a high-definition display element, whenever the pitch of the coating target portion changes, it is necessary to stop the normal printing operation and repeat the approach of the landing pitch many times. Operation. As a result, the operation rate of the inkjet printing device is reduced. In addition, in order to approach the landing point pitch, it is also necessary to prepare a dedicated substrate for testing, or to provide a wide test printing area on the production substrate.

The present invention provides an ink jet that can determine the most appropriate head rotation amount even if the pitch of the coating target portion of the coating object is changed, so that the droplet pitch and the pitch of the coating target portion can be matched with high accuracy Printing method and inkjet printing device using the method.

One aspect of the present invention is an inkjet printing method in which droplets are ejected from the inkjet head while the inkjet head is relatively scanned with respect to the object to be coated, and ink is applied to the object to be coated. The inkjet printing method includes: the first step, reading data related to the landing position offset characteristic from the memory part that memorizes the landing position offset characteristic, the landing position offset characteristic is obtained based on the landing position offset The aforementioned deviation of the landing position is the deviation of the landing position of the droplets discharged from the inkjet head from the target position in each of the first and second rotation angles that are different from each other. shift. In addition, it includes: the second step, which is determined based on the landing position deviation characteristics, the arrangement pitch of the droplet ejection nozzles of the inkjet head, and the coating target pitch of the coating target in the direction orthogonal to the scanning direction The target rotation angle of the inkjet head is output, and a printing pattern corresponding to the target rotation angle is generated. In addition, it includes a third step of controlling the inkjet head to discharge liquid droplets to the application target portion on the application target based on the target rotation angle and the printing pattern.

In addition, another aspect of the present invention is an inkjet printing device that ejects droplets from the inkjet head while scanning the inkjet head relative to the object to be coated, and applies ink on the object to be coated. The inkjet printing device is equipped with a memory unit that stores the characteristics of the landing position deviation, the aforementioned landing position deviation characteristic is calculated based on the landing position deviation, and the aforementioned landing position deviation is the difference between the inkjet heads. For each of the 1 rotation angle and the second rotation angle, the landing position of the droplet discharged from the inkjet head is shifted from the target position. In addition, it is equipped with a calculation unit to obtain the target pitch of the coating target in the direction orthogonal to the scanning direction based on the characteristics of the landing position shift, the arrangement pitch of the droplet ejection nozzles of the inkjet head, and the coating target pitch in the direction orthogonal to the scanning direction The target rotation angle of the inkjet head, and a print pattern corresponding to the target rotation angle is generated. In addition, the inkjet printing device is configured to control the inkjet head to discharge liquid droplets to the application target portion on the application target object based on the target rotation angle and the printing pattern.

According to the above aspect of the present invention, it is possible to provide a method that can match the pitch of the droplets discharged from the inkjet head to the pitch of the coating target even if the pitch of the coating target portion of the coating object is changed. An inkjet printing method and an inkjet printing device using the method.

Detailed description of the preferred embodiment (Implementation form) Hereinafter, the inkjet printing apparatus 40 of the present embodiment will be explained separately with reference to the drawings. (Composition of inkjet printing device)

First, the overall configuration of the inkjet printing apparatus 40 as an example of this embodiment will be described with reference to FIG. 1.

FIG. 1 is a perspective view of an inkjet printing device 40 according to an example of this embodiment.

As shown in FIG. 1, the inkjet printing device 40 of this embodiment includes at least: a stand 18 supporting the device, a surface plate 17 provided on the stand 18, a substrate transfer stage 30, a head unit 32, and a head A unit transfer stage 33, two support parts 16, and the like. The board transfer table 30 transfers the board set on the platform 17 in the X direction. The head unit transfer table 33 transports the head unit 32 in the Y direction orthogonal to the substrate transport table 30. The two supporting parts 16 support both ends of the head unit transfer stage 33 on the platform 17.

The substrate transport table 30 is composed of the following components: a substrate guide rail 5; a substrate transport slider 4, which is guided on the substrate guide rail 5 and supported so as to be slidable in the X direction; a substrate rotation mechanism 3, provided On the substrate conveying slide 4; and the substrate adsorption table (table) 2 is set on the substrate rotating mechanism 3. The substrate transport slider 4 is controlled by a substrate transport linear motor 6, a substrate transport position detection unit 7, and a substrate transport table control unit (not shown).

In addition, the substrate rotation mechanism 3 includes a substrate rotation angle detection unit and a substrate rotation drive unit that are not shown. The substrate rotation mechanism 3 is configured such that it can be precisely positioned to a target rotation angle by a substrate rotation mechanism control unit (not shown).

On the other hand, the head unit transfer table 33 is composed of the following components: a head unit transfer guide 13; and a head unit transfer slider 12, which is guided on the head unit transfer guide 13, and It is supported to be slidable in the Y direction. The slider 12 for head unit transfer is controlled by the linear motor 14 for head unit transfer, the position detection part 15 for head unit transfer, and the head unit transfer stage control part which is not shown in figure.

The head unit 32 is configured by mounting an inkjet head 23 and an alignment camera 21 on a head unit base 22 attached to the head unit transfer slider 12. In addition, the inkjet head 23 includes a head rotating mechanism 10 mounted on the head unit base 22 through a bracket 11, and an inkjet head mounted below the head rotating mechanism 10 through a head bracket 9 8 and so on. The head rotation mechanism 10 includes a head rotation angle detection unit, a head rotation drive unit, and the like, which are not shown in the figure. The head rotation mechanism 10 is configured such that it can be precisely positioned to 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 can control the ejection timing for each droplet ejection nozzle of the inkjet head 8 based on the detection position obtained by the substrate transport position detection unit 7. In addition, the plurality of droplet ejection nozzles of the inkjet head 8 are arranged in a row at a predetermined pitch, for example.

The inkjet head control unit 100 is constituted by a microcomputer that controls the discharge operation of the inkjet head 8. Specifically, the inkjet head control unit 100 includes, for example: CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), input Port, and output port, etc.

In addition, the inkjet head control unit 100 includes a storage unit 110, a calculation unit 120, and the like. The storage unit 110 stores the droplet landing position offset characteristics when the droplet is ejected from the inkjet head 8. The arithmetic unit 120 calculates the ink jet based on the landing position offset characteristics, the arrangement pitch of the droplet ejection nozzles of the inkjet head 8, and the application target pitch of the application target in the direction orthogonal to the scanning direction. The target rotation angle of the head 8 and a print pattern corresponding to the target rotation angle are generated. In addition, the above-mentioned landing position deviation characteristic is obtained based on the landing position deviation, and the above-mentioned landing position deviation is that the inkjet head 8 has a first rotation angle and a second rotation angle that are different from each other. The landing position of the droplet discharged from the inkjet head 8 is shifted from the target position. The details will be described later.

In addition, an air bearing mechanism is used in the substrate transfer table 30 and the head unit transfer table 33 of this embodiment. In this way, high-precision positioning can be achieved. (Operation of inkjet printing device)

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

Fig. 2 is a plan view showing a substrate 1 of an object to be coated according to an example of the present embodiment.

As shown in FIG. 2, the substrate 1 has a machine material 1a, an alignment mark 1b formed on the machine material 1a, a bank 1c, a coating target part 1d, a test printing area 1e, and the like. Alignment marks 1b are formed at 4 corners on the machine material 1a. The bank portion 1c serves as a guard so that the ink already printed on the application target portion 1d does not overflow. The application target part 1d is surrounded by the bank part 1c, and is arrange|positioned at a certain pitch. The test print area 1e has a drop point measurement area 1f, which is provided to measure the drop point position of the liquid drop.

The drop point measurement area 1f is formed in the test print area 1e. The drop point measurement area 1f is formed on the extension line of the application target portion 1d at the same pitch as the application target portion 1d.

In addition, the application target portion 1d is an area of pixels constituting the display panel. The application target portion 1d is configured to diffuse the dropped droplets. On the other hand, the drop point measurement area 1f is configured to have liquid repellency. Thereby, the droplet that has landed on the landing point measurement area 1f is maintained in a circular shape. Therefore, by shooting the position of the dropped droplet with the aiming camera 21 and processing it by an image processing unit not shown, it is possible to measure the center of the circle of the drop measuring area 1f with high accuracy. Location.

The substrate 1 further includes a coating area 1g. The application area 1g is composed of a liquid-repellent area similarly to the drop point measurement area 1f. In addition, the application area 1g is an area provided to measure the approximate position of the droplet when the droplet does not enter the circle of the droplet measurement area 1f. (When substrate 1 and inkjet head 8 do not move relative to each other)

Next, use the diagram for the relationship between the position of the droplet ejection nozzle of the inkjet head 8 and the landing position of the droplet ejected from the droplet ejection nozzle on the substrate 1 when the substrate 1 and the inkjet head 8 do not move relative to each other. 3A to 4B to illustrate.

FIG. 3A is a plan view explaining the displacement of the landing position caused by the tendency of the ejection angle of the droplets ejected from the inkjet head 8. Fig. 3B is a side view of Fig. 3A.

FIG. 4A is a plan view illustrating the displacement of the landing position caused by the droplet ejection angle tendency when the rotation angle of the inkjet head 8 is 0 (zero) degrees. Fig. 4B is a plan view illustrating the displacement of the landing position caused by the droplet ejection angle tendency when the rotation angle of the inkjet head is φ degrees.

Here, the inkjet head 8 shown in FIG. 3A has four liquid droplet ejection nozzles indicated by dotted circles. In addition, the hole positions of the droplet ejection nozzles are set to n ₁ , n ₂ , n ₃ , and n ₄ . In general, each of the droplet ejection nozzles tends to have different ejection directions (corresponding to the above-mentioned ejection angle tendency) due to processing accuracy during manufacturing. Therefore, as shown in FIG. 3B, the landing positions will be the landing positions P ₁ , P ₂ , P ₃ , and P ₄ shown by the solid circles. The landing position when the droplet ejection nozzle surface is just a distance G from the surface of the substrate 1. That is, the landing positions P ₁ , P ₂ , P ₃ , and P ₄ will reach positions different from directly below the hole positions n ₁ , n ₂ , n ₃ , and n _{4 of the droplet ejection nozzle.} Hereinafter, the amount of positional deviation will be referred to as "deflection of the position of the landing point" caused by the tendency of the discharge angle.

In addition, the displacement of the landing position caused by the tendency of the ejection angle from each droplet ejection nozzle is determined by the shape accuracy of the hole of the droplet ejection nozzle or the surface condition around the droplet ejection nozzle. In other words, the ejection angle from the droplet ejection nozzle tends to be fixed in the inkjet head 8 incorporated. Therefore, compared with the case where 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. The hole positions n ₁ , n ₂ , n ₃ , and n _{4 of the} droplet ejection nozzles and the landing positions P ₁ , P ₂ , P ₃ , and P _{4 are} still shifted in the same direction in the inkjet head 8. That is, FIG. 4B, which is a plan view when the inkjet head 8 is rotated by φ degrees, becomes a position where FIG. 4A is directly rotated by exactly φ degrees. 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, for the landing position when the substrate 1 is traveling at a constant speed V with respect to the inkjet head 8 and the droplet is ejected from the droplet ejection nozzle of the inkjet head 8 toward the substrate 1, FIGS. 5A to 6B are used. To illustrate.

FIG. 5A is a plan view explaining the displacement of the landing position of the droplets discharged from the inkjet head 8 when the application target is stopped. Fig. 5B is a side view of Fig. 5A. FIG. 6A is a plan view explaining the displacement of the landing position of the droplets discharged from the inkjet head when the coating target is traveling at a speed V. FIG. Fig. 6B is a side view of Fig. 6A.

As shown in FIG. 5A, in the state where the substrate 1 is stopped, the landing position of the droplet ejected from the droplet ejection nozzle _{at the hole position n 1 of the inkjet head 8 on the substrate 1 is set to P 1} . Further, the position P ₁ of apertures placement position offset n ₁ corresponds to FIG. 4A and 4B are described as favoring the discharge caused by the landing position offset. On the other hand, the discharged liquid droplet ejection nozzle hole from the droplet position with the speed n ₁ is flying toward the constant speed V 1 to the traveling substrate. Therefore, it may take time until the droplet reaches the substrate 1. If this time is set to Δt, the substrate 1 will travel exactly Δt×V during this period. Thus, as shown in FIG. 6A, the droplet landing position on the substrate 1 Q ₁ with respect to the substrate 1 in a stopped state drop landing position point P ₁ becomes somewhat offset.

In addition, in fact, when the droplet is flying toward the substrate 1, the droplet will flow due to the influence of air resistance and deceleration, or the influence of the wind generated by the walking of the substrate 1, which will become more complicated. The position offset. _{Hereinafter, such an impact position deviation ΔX 1v} in the walking direction caused by the walking of the substrate 1 is referred to as "an impact position deviation" caused by walking. That is, the positional deviation of the landing point caused by such walking is the positional deviation of the landing point accompanying the walking of the substrate 1, so it is basically a positional deviation caused in the walking direction. Therefore, unlike the positional deviation caused by the tendency of the ejection angle of the inkjet head 8, even when the inkjet head 8 has been rotated, it does not rotate together with the rotation of the inkjet head 8.

As explained above, when the substrate 1 is stopped, the landing position of the droplet ejected from the hole position n _{1 of} the droplet ejection nozzle on the substrate 1 becomes the landing position caused only by the inclination of the ejection angle. The offset point position P ₁ . On the other hand, when the substrate 1 is traveling at a speed V, the landing point will be at the position of the landing position P ₁ plus the landing position offset ΔX1v. The landing position P ₁ is due to the discharge The angular tendency causes the position of the drop point to shift, and the aforementioned drop point position shift ΔX1v is the shift caused by the substrate 1 walking in the traveling direction.

Next, the method of printing liquid droplets on the application target portion 1d of the substrate 1 will be described in 1) and 2) below.

1) At the beginning, the alignment method of the substrate 1 will be described.

First, the substrate 1 is suction-fixed on the substrate suction table 2 and the substrate transfer table 30 and the head unit transfer table 33 are moved.

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

Next, the alignment camera 21 is used to photograph the alignment mark 1b, and the position of the alignment mark 1b is measured by an image recognition unit not shown. On the other hand, based on the detection position obtained by the substrate transport position detection section 7 and the detection position obtained by the head unit transfer position detection section 15 at the time, a control section not shown drives the substrate rotating mechanism 3 and The adjustment is performed so that the traveling direction of the substrate transfer table 30 and the direction of the coating target portion 1d of the substrate 1 become parallel.

2) Next, the position adjustment method of the droplet ejection nozzle and the application target portion 1d of the substrate 1 will be described using FIG. 7.

FIG. 7 is a diagram illustrating the position of the droplet ejected when the inkjet head is set to the first rotation angle (here, the rotation angle is 0 (zero) degrees) when the coating target is traveling at a speed V Floor plan.

In FIG. 7, the dotted circles in the figure indicate the hole positions n ₁ , n ₂ , n ₃ , and n ₄ of the droplet ejection nozzles in the inkjet head 8. In addition, the solid-line circles indicate the landing positions P ₁ , P ₂ , P ₃ , and P _{4. The} aforementioned landing positions P ₁ , P ₂ , P ₃ , and P ₄ are due to the droplets discharged from the droplet discharge nozzle The discharge angle tends to cause a position shifted when it reaches the substrate 1. In addition, the double solid-line circle in FIG. 7 represents the drop point positions Q ₁ , Q ₂ , Q ₃ , and Q ₄ , and the aforementioned drop point positions Q ₁ , Q ₂ , Q ₃ , and Q ₄ are the opposite drop point positions P ₁ , P _2. P ₃ and P _{4 are} added to the position after the landing position offset caused by walking. The landing position offset caused by the aforementioned walking is the offset caused by the walking of the substrate 1.

In addition, in FIG. 7, in order to make the droplet pitch in the Y direction of the inkjet head 8 match the coating target pitch W _{0 of the} coating target portion 1d, the rotation angle is positioned to 0 degrees, and the aforementioned rotation angle is inkjet The rotation axis of the head 8 has a rotation angle around the rotation center O shown by a black circle. (Calculation of the offset characteristic of the landing position)

Next, for the method of calculating the characteristic of the landing position shift (hereinafter referred to as "the landing position shift characteristic") that occurs when the inkjet printing device 40 ejects droplets from the inkjet head 8, FIGS. 8A to 8 are used. Figure 8E to illustrate.

Fig. 8A is a diagram illustrating the position of the ejected droplets and the coating position when the rotation angle of the inkjet head is 0 degrees in the state of Fig. 7, that is, when the coating object is traveling at a speed V. A plan view of the amount of positional deviation in the Y direction of the application target portion 1d of the object.

In addition, in Figure 8A, the droplet landing positions Q ₁ , Q ₂ , Q ₃ , Q ₄ in the Y direction and the center axis of the coating target portion 1d in the Y direction, each with ΔY ₁₀ , ΔY ₂₀ , ΔY ₃₀ , and ΔY ₄₀ are expressed.

That is, regarding the alignment of the inkjet head 8 and the substrate 1 in the Y direction, the alignment is such that the total error of _{ΔY 10} , ΔY ₂₀ , ΔY ₃₀ , and ΔY _{40 is minimized.}

8B is a description of the state of FIG. 7, that is, when the coated object is traveling at a speed V, and the rotation angle of the inkjet head 8 is 0 degrees, the landing position of the discharged droplets A plan view of the distance from the Y axis in the X direction.

Further, in FIG. 8B, the liquid droplet landing position is _{Q 1, Q 2, Q 3} , Q 4 and Y-axis distance in the X direction, each in _{X 1S0, X 2S0, X 3S0} , X 4S0 to Express.

And, FIG. 8C is a graph showing the X-direction have a distance that is equivalent to _{X 1S0, X 2S0, X 3S0} , X 4S0 landing position under the discharge timing correction case. That is, as shown in FIG. 8C, by adjusting the ejection timing correction, the droplets can be ejected from all the droplet ejection nozzles to reach the substrate 1 and the landing position is almost aligned on the Y axis (including the Y axis) for printing. . Hereinafter, this kind of printing pattern is referred to as the "first printing pattern".

In addition, FIG. 8D shows the landing position of the droplet when it has been printed on the landing measurement area 1f and the application target portion 1d of the substrate 1 in the above-mentioned state. Hereinafter, this printing is referred to as the "first printing step". Here, in FIG. 8D, the droplets in the application target portion 1d are represented by double circles. However, actually, the application target portion 1d has hydrophilicity. Therefore, the droplets that have landed on the application target portion 1d become diffused in the application target portion 1d. On the other hand, the drop point measurement area 1f has liquid repellency. Therefore, as shown in FIG. 8D, the droplet that has landed on the landing point measurement area 1f becomes a circular shape in a circle surrounding the landing point measurement area 1f.

In addition, FIG. 8E is an enlarged view of part A in FIG. 8D displayed together with the plan view of FIG. 8D.

In the above state, the impact measurement area 1f of FIG. 8E is shot with the camera 21 aimed at, and image processing is performed. In addition, the _{Y-direction positional deviation ΔY i0 between the circle of the landing measurement area 1f of the coating target distance W 0} and the circle of the droplet in the landing measurement area 1f and the positional deviation ΔX i0 in the X-direction are _detected. (i=1, 2, 3, 4). In this way, it is possible to accurately measure the positional deviation of the droplet's landing point. Hereinafter, this measurement will be referred to as the "first landing point position shift detection step".

_{As a result, the measurement results ΔX i0} and ΔY _i0 , which are shifted from the drop position of the droplet in the above-mentioned landing measurement area 1f, _{and the correction amount X iS0} shifted by the correction of the discharge timing of FIG. 8C, are It is possible to accurately calculate the position of the landing point without correcting the discharge timing. Hereinafter, this calculation step is referred to as the "first landing position calculation step". In addition, the calculated landing position data is set as the "first landing position data".

Next, in the case where the coating target pitch of the coating target portion 1d is W _{1 smaller than W 0} , in order to make the droplet pitch match W ₁ , the inkjet head 8 is moved around the axis of rotation, that is, the center of rotation. The situation of O rotated by θ degrees for coating will be explained using FIGS. 9A to 9E.

9A is a diagram illustrating the position and application of the droplets discharged when the inkjet head 8 is set to the second rotation angle (here, the rotation angle θ degrees) when the coating object is traveling at a speed V A plan view of the amount of positional deviation in the Y direction of the application target portion 1d of the object. In addition, in FIG. 9A, the droplet landing positions Q ₁ , Q ₂ , Q ₃ , Q ₄ in the Y direction and the center axis of the coating target portion 1d in the Y direction, each with ΔY _1θ , ΔY _2θ , ΔY _3θ , and ΔY _4θ are expressed.

In addition, in the alignment of the inkjet head 8 and the substrate 1 in the Y direction, the alignment is such that the total error of _{ΔY 1θ} , ΔY _2θ , ΔY _3θ , and ΔY _{4θ is minimized.}

9B is a diagram illustrating the position of the drop point and Y of the ejected droplet when the rotation angle of the inkjet head 8 is θ degrees in the state of FIG. Plan view of the distance of the axis in the X direction.

In addition, in FIG. 9B, the droplet landing positions Q ₁ , Q ₂ , Q ₃ , _{and the distance between Q 4} and the Y axis in the X direction are taken as X _1Sθ , X _2Sθ , X _3Sθ , X _4Sθ Express.

In addition, FIG. 9C shows the droplet landing position when the ejection timing _{of the distances X 1Sθ} , X _2Sθ , X _3Sθ , and X _4Sθ corresponding to the X direction shown in FIG. 9B has been corrected. That is, as shown in FIG. 9C, by adjusting the ejection timing, the landing positions of the droplets ejected from all the droplet ejection nozzles and reach the substrate 1 can be almost aligned on the Y axis (including the Y axis). Hereinafter, this printing pattern is referred to as the "second printing pattern".

FIG. 9D shows the landing position of the droplet in the case where the landing point measurement area 1f and the application target portion 1d of the substrate 1 have been printed in the state of FIG. 9C. Hereinafter, this printing is referred to as the "second printing step". In addition, in FIG. 9D, the droplets in the application target portion 1d are represented by double circles. However, actually, the application target portion 1d has hydrophilicity. Therefore, the droplets that have landed on the application target portion 1d become diffused. On the other hand, the drop point measurement area 1f has liquid repellency. Therefore, as shown in FIG. 9D, the droplet that has landed on the landing point measurement area 1f becomes a circular shape in a circle surrounding the landing point measurement area 1f.

In addition, FIG. 9E is an enlarged view of the portion A in FIG. 9D displayed together with the plan view of FIG. 9D.

In the above-mentioned state, the impact measurement area 1f of FIG. 9E is captured by aiming at the camera 21, and image processing is performed. And, detecting a target pitch circle coated droplets measured within a circle with the placement region 1f 1f W is the placement of _a measurement area _ΔY iθ positional deviation in the Y direction and the position in the X direction offset _ΔX iθ (i=1, 2, 3, 4). In this way, it is possible to accurately measure the positional deviation of the droplet's landing point. Hereinafter, this measurement will be referred to as the "second step of detecting displacement of the landing position".

_{As a result, the measurement results ΔX iθ} and ΔY _iθ that deviate from the drop position of the drop in the drop measurement area 1f described above _{, and the correction amount X iSθ} shifted by the correction of the discharge timing of FIG. 9C, are It is possible to accurately calculate the position of the landing point without correcting the discharge timing. Hereinafter, this calculation step is referred to as the "second landing position calculation step". In addition, the calculated landing position data is set as the "second landing position data".

In addition, in this embodiment, the relative movement speed of the inkjet head 8 and the substrate 1 in the above-mentioned first printing step and the relative movement speed of the inkjet head 8 and the substrate 1 in the second printing step are set to same.

_{As described above, for the substrate with the coating target pitch W 0} of the coating target portion 1d shown in FIG. 8A and _{the substrate with the coating target pitch W 1} of the coating target portion 1d shown in FIG. 9A, make The inkjet head 8 rotates by θ degrees. Thereby, it is possible to print by matching the coating target pitch of the droplets with the coating target pitch of the coating target portion.

At this time, for the application target pitches of the different application target portions 1d, the respective droplet landing positions can be accurately measured.

Then, based on the measurement results of the drop positions of the droplets on the above-mentioned two kinds of substrates 1, the most appropriate rotation angle of the inkjet head 8 that minimizes the deviation of the drop points is calculated for a substrate with an arbitrary coating target pitch. With this, it is possible to apply droplets to an appropriate position on a substrate of an arbitrary coating target pitch without performing test printing.

Hereinafter, the above-mentioned method will be explained using FIG. 11.

FIG. 11 is a diagram showing that for one nozzle in the inkjet head 8, when the rotation angle around the rotation center O of the head is 0 (zero) degrees, and when it is rotated by θ degrees therefrom, the respective A graph showing the relationship between the drop point positions. Here, the X coordinate of the rotation center O of the head is set to δx, and the Y coordinate is set to δy. In addition, the position of the landing point when the rotation angle is 0 degrees is set to Q ₀ , _{the X coordinate of Q 0} is set to Xa, and the Y coordinate is set to Ya, which is marked as Q ₀ (Xa, Ya). On the other hand, the position of the landing point when the rotation angle is θ degrees is Q _θ , and _{the X coordinate of Q θ} is set to Xb and the Y coordinate is set to Yb, which is denoted as Q _θ (Xb, Yb). In addition, the positional deviation in the X direction of the droplet landing position caused by the traveling of the substrate 1 is set to ΔX _V.

That is, in the case of coating on the traveling substrate 1, the position of the droplet ejected from the inkjet head 8 and landed on the substrate 1 will be offset as follows: The offset of the landing position caused by the tendency of the discharge angle at the time is added to the offset of the landing position caused by the walking of the substrate 1. At this time, as described above, the displacement of the landing position caused by the tendency of the ejection angle rotates together with the rotation of the inkjet head 8. On the other hand, the displacement of the landing position caused by the traveling of the substrate 1 does not depend on the rotation of the inkjet head 8 but is determined by the traveling direction of the substrate 1. _{That is, the landing positions P 0} and P _θ caused by the respective ejection angle tendencies of the rotation angle of the inkjet head 8 at 0 degrees and θ degrees will each be: the X coordinate of _{P 0 becomes Xa-ΔX V} , the Y coordinate It becomes Ya; the X coordinate of _{P θ becomes Xb-ΔX V} , and the Y coordinate becomes Yb.

In addition, the landing position P _θ corresponds to a position obtained by _{rotating the landing position P 0} about the head rotation axis, that is, the rotation center O by θ degrees. Therefore, the relationship between the point of the landing position P _{θ and} the point of the landing position P ₀ can be expressed as the following formulas (1) and (2) based on the calculation formula of the rotation of the coordinates.

_{Moreover, by the above formulas (1) and (2), the positional deviation ΔX V} caused by the Y coordinate δy of the rotation axis of the inkjet head 8 and the travel of the substrate 1 can be as shown in formulas (3) and (4) Come to find out. In addition, the X-axis coordinate δx of the rotation axis of the inkjet head 8 needs to be measured separately. The measurement method will be described later.

As described above, the X coordinate δx of the head rotation center O of the inkjet head 8 is obtained in advance. In addition, in the method of printing while moving the substrate 1 at a speed V, the rotation angle of the inkjet head 8 is measured as two angles of 0 degrees (first rotation angle) and θ degrees (second rotation angle) The lower landing position Q ₀ (Xa, Ya) (the first landing position data), Q _θ (Xb, Yb) (the second landing position data). In this way, it is possible to obtain the positional deviation ΔX _V of the drop point caused by the traveling of the substrate 1. In addition, as long as the impact position deviation ΔX _V can be obtained, the impact position deviation due to the inclination of the discharge angle can be obtained. Hereinafter, such a calculation step is referred to as a "drop point position deviation characteristic calculation step".

The data related to the characteristic of the landing position offset calculated by the above-mentioned method is stored in the memory 110 as data showing the inherent characteristics of the inkjet head 8 used.

In addition, the droplet ejection operation for calculating the landing position deviation characteristic is, for example, when the landing point measurement area 1f is applied with the droplets at the time of printing and coating the target portion 1d. In addition, it can be implemented by measuring the displacement of the drop point of the drop in the drop point measurement area 1f. (Operation at the time of printing execution)

The calculation unit 120 of the inkjet printing device 40 uses the landing position offset characteristics calculated by the above-mentioned method to obtain the target rotation angle of the inkjet head 8 when printing is performed. In addition, the computing unit 120 generates a print pattern corresponding to the target rotation angle.

In addition, in the present embodiment, when the droplets are discharged from the respective droplet discharge nozzles of the inkjet head 8, the rotation angle at which the positional deviation of the application target portion 1d of the application object becomes the smallest is set as printing The target rotation angle of the inkjet head 8 at the time of execution.

Hereinafter, such a target rotation angle may be referred to as the "optimal rotation angle". At this time, the target rotation angle is preferably set so that when the droplets are discharged from the respective droplet discharge nozzles of the inkjet head 8, the positional deviation in the application target portion 1d of the application target becomes less than the threshold value. Rotation angle.

Hereinafter, the inkjet head 8 is calculated from the landing position offset characteristics obtained above and the rotation center O (δx, δy) of the inkjet head 8 in a printing method while the substrate 1 is traveling at a speed V. The method of calculating the impact position of the arbitrary third rotation angle φ will be described with reference to FIG. 12. _{In addition, the impact position deviation characteristics include the impact position deviation ΔX V} caused by the walking of the substrate 1 and the impact position deviation caused by the ejection angle tendency.

FIG. 12 is a diagram illustrating the positional deviation of the droplet landing point when the head rotation angle of the inkjet head 8 is 0 degrees and when φ degrees.

First, the computing unit 120 reads the data related to the offset characteristic of the landing point that has been stored in the memory unit 110.

_{Next, the computing unit 120 subtracts the landing position offset ΔX V} caused by walking from the X coordinate _{of the landing position Q 0} (Xa, Ya) where the rotation angle of the inkjet head 8 is 0 degrees. In addition, the calculation unit 120 obtains the landing position P ₀ (Xa-ΔX _V , Ya) of the droplet when only the ejection angle tends to be present.

Next, the arithmetic unit 120 obtains only the presence of the liquid droplet landing position in a case that the placement position P ₀ of the first _point about the rotational center i.e. a rotation center O of the rotation angle [Phi] of the discharge tendency P _φ (Xd, Yd ). In addition, the computing unit 120 _{adds the impact position offset ΔX V} caused by the walking of the substrate 1 to the X coordinate of the _{found impact position P φ} point. In this way, the impact position Q _φ (Xe, Ye) of the rotation angle φ can be obtained. If this is expressed by the formula, _{the coordinates of the landing position P φ} can be expressed by formulas (5) and (6), and _{the coordinates of the landing position Q φ} can be expressed by formulas (7) and (8) To represent. Hereinafter, the step of calculating the landing position of the third rotation angle φ of the inkjet head 8 is referred to as the "pointing position prediction step".

At this time, the computing unit 120 changes the third rotation angle φ of the inkjet head 8 in various ways, and calculates the landing position of the droplet for each of the plurality of third rotation angles φ.

_{Next, the computing unit 120 obtains the most appropriate rotation angle φ c} of the inkjet head 8 when the inkjet head 8 discharges liquid droplets from the inkjet head 8 to the application target portion 1d of the application target object. In detail, the calculation unit 120 is calculated based on the arrangement pitch of the droplet ejection nozzles of the inkjet head 8 and the application target pitch of the application target portion 1d of the application target in the direction orthogonal to the scanning direction. Find the most appropriate rotation angle φ _c . Specifically, the arithmetic unit 120 first calculates, for example, an evaluation value related to the positional deviation of the droplet. The positional deviation of the droplet is each of the plurality of third rotation angles φ degrees of the inkjet head 8. The position of the droplet in the angle is shifted from the application target portion 1d. In addition, the calculation unit 120 uses the calculated evaluation value as a reference to obtain the most appropriate rotation angle φ _c .

In addition, in the above-mentioned equations (7) and (8), the calculation equations for the landing position of one droplet ejection nozzle at the rotation angle φ degree of the inkjet head 8 are shown.

In the following, for the case of the inkjet head 8 provided with a plurality of droplet ejection nozzles, the formula for the landing position of the droplet ejection nozzles is shown.

That is, let the rotation angle of the inkjet head 8 of the droplet ejection nozzles of sort i be 0 degrees (the first rotation angle) as the landing position coordinates of (X _ia , Y _ia ), and the rotation angle of θ degrees (the first rotation angle). 2 Rotation angle) The landing position coordinates are set to (X _ib , Y _ib ), and the position offset caused by the walking of the nozzles of sort i is set to ΔX _iv . In addition, if the landing position coordinates of the rotation angle φ (the third rotation angle) are set to (X _ie , Y _ie ), the value of the landing position coordinates can be expressed as the following equations (9) and (10) ).

_{Here, the position shift amount ΔX iv} caused by the traveling of the nozzles of the sort i can be expressed by equation (11).

Also, if the Y coordinate of the application target portion of _{the droplet ejection nozzle of sort i is set to Y ti} and the Y coordinate of the drop point position of the droplet ejection nozzle of sort i is set to Y _ie , the difference ΔY _{i φ is} It can be expressed by equation (12).

Here, FIGS. 10A to 10E show the relationship between the _{above-mentioned difference ΔY i φ} and the position shift amount ΔX _iv. In addition, i shown in FIGS. 10A to 10E shows four droplet ejection nozzles of 1, 2, 3, and 4.

In addition, in order to obtain the most appropriate rotation angle φ _{c of} the inkjet head 8, the computing unit 120 shifts the Y-direction positions of all the droplet ejection nozzles by the mean square value Δt of _{ΔY i φ as shown in equation (13)} Calculate as an evaluation value.

Next, the computing unit 120 changes the rotation angle φ, calculates the mean square value Δt at each rotation angle φ, and obtains the value of the rotation angle φ at which the mean square value Δt is the smallest. In addition, the rotation angle φ at which the mean square value Δt is the smallest becomes the most appropriate rotation angle φ _c of the inkjet head 8.

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

Further, the arithmetic unit 120 to the X-direction, is the placement of each droplet ejection nozzle position coordinates _{X ie} φc in the X direction by the formula (15) is calculated, and the correction amount corresponding to the timing of the discharge _{-X ie} φc. Hereinafter, the printed pattern with the corrected discharge timing will be referred to as the "optimal printed pattern". In addition, this generation step is called "the most suitable print pattern generation step".

Further, the rotation angle of the inkjet head 8 has been set to the most appropriate rotation angle φ _c case, the placement of each of the droplet ejection nozzle position coordinates _{Y ie} φc is of formula (16) in the Y direction is calculated. In addition, the positional offset ΔY _{ie φc} in the Y direction from the target coordinates is calculated by equation (17). Further, in consideration of the case where the Y-direction of the deviation, Y coordinates of the deposition point is to be _{Y ie} φc -Δy.

That is, the inkjet head control unit 100 of the inkjet printing device 40 positions the inkjet head 8 to the optimum rotation angle φ _c calculated above and the offset amount Δy in the Y direction, and performs the above-mentioned optimum printing pattern. print. Thereby, the inkjet printing device 40 can discharge the droplets so that the positional deviation with respect to the application target portion 1d is minimized.

In addition, during printing, the inkjet printing device 40 controls the substrate transport table 30 so that the relative movement speed of the inkjet head 8 and the substrate 1 becomes the same as the speed in the first printing step and the second printing step described above.

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

10B shows the position of the droplet ejection nozzles of No. 1, 2, 3, and 4 when the head rotation angle of the inkjet head 8 has been set to the optimum rotation angle φ _{c obtained above.} The graph of the distance in the X direction from the Y axis.

FIG. 10C is a diagram showing the landing position when the discharge timing corresponding to the X-direction distance between the landing position of each droplet discharge nozzle of FIG. 10B and the Y axis has been corrected. That is, as shown in Fig. 10C, if the ejection timing is corrected to exactly -X _ieΦc , the landing position of each droplet ejection nozzle will overlap on the Y axis. The aforementioned -X _ieΦc is calculated by the above equation (15) The opposite direction of the amount of output.

In addition, FIG. 10D is a diagram showing that a droplet is applied to the substrate 1 in the above-mentioned 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 deviation between the landing position of each droplet ejection nozzle and the application target position is minimized.

In addition, FIG. 10E is an enlarged view of the drop point position in the drop point measurement area 1f when it is actually applied, which is displayed together with the plan view of FIG. 10D. In addition, in FIG. 10E, the landing positions of the droplets discharged from the third and fourth droplet discharge nozzles in the landing point measurement area are displayed. It can be seen from FIG. 10E that the positional deviation amounts ΔX _{3 φc} and ΔX _{4 φc} from the target position in the X direction of the actually dropped droplet almost become the target position.

In addition, when it is desired to get closer to the above-mentioned positional deviation amounts ΔX _{3 φc} and ΔX _{4 φc} , the discharge timing can be corrected according to the positional deviation amount. Thereby, the positional deviation amounts ΔX _{3 φc} and ΔX _{4 φc can be} further reduced. (How to find the coordinates of the rotation center of the inkjet head)

Next, how to obtain the coordinates of the rotation center O (δx, δy) of the inkjet head 8 will be described using FIG. 13.

FIG. 13 is a plan view illustrating the position of the droplet of the inkjet head 8 before and after the rotation of θ degrees when the application target is stopped.

At this time, since the printing target is stopped, there will be no positional deviation due to walking, but only positional deviation due to the tendency of the ejection angle from the droplet ejection nozzle. That is, if the landing position before rotation is set to P _0V0 (Xa _V0 , Ya _V0 ), and the landing position after rotation θ degrees is set to P _θV0 (Xb _V0 , Yb _V0 ), the landing position P _{θV0 is} This corresponds to the position where the landing position P _{0V0 is} rotated by θ degrees around the rotation center O. Therefore, the relationship of the coordinates can be expressed by the following equations (18) and (19).

In addition, if the coordinates (δx, δy) of the rotation center O of the inkjet head 8 are obtained from the above-mentioned formulas (18) and (19), it becomes as shown in the formulas (20) and (21).

In addition, the task of specifying the coordinates of the rotation center O of the inkjet head 8 may be performed only once at the beginning when the inkjet head 8 is mounted on the head rotation mechanism 10. In addition, although it is not necessary to use all the droplet ejection nozzles for the above operation, it is preferable to select a nozzle with high ejection reproducibility by using two droplet ejection nozzles separated by a distance near both ends of the inkjet head 8. Implement.

As described above, according to the inkjet printing device 40 of the present embodiment, the landing position deviation characteristic is first calculated based on the landing position deviation. For each of the angle and the second angle of rotation, the droplet discharged from the inkjet head 8 is shifted from the target position of the landing position. In addition, it becomes possible to set the most appropriate head rotation of the inkjet head 8 for the coating target portion 1d of any coating target pitch based on the calculated landing position offset characteristics without performing test printing. Quantity to be printed.

The above method can be implemented by applying droplets to the landing point measurement area 1f while actually printing the coating target portion 1d, and measuring the offset of the landing point position in the landing point measurement area 1f. Therefore, in the production of the substrate 1 coated with the target pitch W _{0 and} the substrate 1 coated with the target pitch W ₁ , the displacement of the landing point position will be measured. In addition, based on the measurement result of the landing position deviation, the rotation angle of the droplet ejection head of the inkjet head 8 is set so that the landing position deviation is minimized for the substrate 1 of an arbitrary coating target pitch. As a result, according to the inkjet printing device 40 of this embodiment, even if it is necessary to take into account the displacement of the landing position caused by the ejection angle tendency of the droplet ejection nozzles, it is possible to perform test printing at the same time. Steps such as reducing the operating rate are suppressed to a minimum while performing high-precision printing.

As described above, according to the inkjet printing apparatus 40 of the present embodiment, it is possible to measure the droplet droplet tendency by actually producing the substrate without using a special substrate for measuring the droplet tendency. In addition, based on the measured results, it is possible to accurately apply liquid droplets to the substrate without performing test printing for a substrate of an arbitrary coating target pitch. As a result, the operation rate is improved, and high-definition display panel printing can be performed.

1: Substrate 1a: Machine material 1b: Alignment mark 1c: Embankment 1d: Coating target portion 1e: Test printing area 1f: Falling point measurement area 1g: Coating area 2: Substrate suction table 3: Substrate rotation mechanism 4: Substrate Transport slider 5: Board guide rail 6: Linear motor for substrate transport 7: Substrate transport position detection unit 8: Inkjet head 9: Head carriage 10: Head rotation mechanism 11: Carriage 12: Slider for head unit transfer 13: Guide rail for head unit transfer 14: Linear motor for head unit transfer 15: Position detection part for head unit transfer 16: Support part 17: Platform 18: Stage 21: Camera 22: Head unit base 23: Inkjet Head 30: substrate transfer table 32: head unit 33: head unit transfer table 40: inkjet printing device 100: inkjet head control section 101: application target section 108: inkjet head 110: memory section 117: droplets Discharge nozzle 118: droplet 119: substrate 120: calculation section G: distance L: pitch n ₁ , n ₂ , n ₃ , n ₄ : hole position O: rotation center P ₀ , P _θ , P _φ , P ₁ , P ₂ , P ₃ , P ₄ , P _θV0 , P _0V0 , Q ₀ , Q _θ , Q _φ , Q ₁ , Q ₂ , Q ₃ , Q ₄ : Fall position V: Speed W ₀ , W ₁ , W ₂ : Coating target spacing X, Y, Z: direction θ, φ: rotation angle φ _c : optimal rotation angle Δt: mean square value δx, Xa, Xb, Xd, Xe, Xa _V0 , Xb _V0 : X coordinate ΔX _V , _{ΔX i0, ΔX 30, ΔX 40} , ΔX iθ, ΔX 3θ, ΔX 4θ: _Is0 X position shift in the X _direction, X iSθ: correction amount _{X 1S0, X 2S0, X 3S0} , X 4S0, X 1Sθ, X 2Sθ , X _3Sθ , X _4Sθ : the distance in the X direction X _ia , X _ib , X _ie , X _{ie φc} , X _{1e φc} , X _{2e φc} , X _{3e φc} , X _{4e φc} : the landing position coordinate ΔX in the X direction _{iv, ΔX 1v, ΔX 2v,} ΔX 3v, ΔX 4v, ΔX 3 φc, ΔX 4 φc: the position shift amount δy, Ya, Yb, Yd, Ye, Ya V0, Yb V0, Y ti: Y coordinate Y _ia, Y _ib ,Y _ie ,Y _{ie φc} : the coordinates of the landing position in the Y direction ΔY _i0 , ΔY ₁₀ , ΔY ₂₀ , ΔY ₃₀ , ΔY ₄₀ , ΔY _iθ , ΔY _1θ , ΔY _2θ , ΔY _3θ , ΔY _4θ : Y direction ΔY _{i φ} , ΔY _{1 φ} , ΔY _{2 φ} , ΔY _{3 φ} , ΔY _{4 φ} : difference S1~S10: step Sudden

Fig. 1 is a perspective view of an inkjet printing apparatus as an example of the embodiment.

Fig. 2 is a plan view showing a substrate of an object to be coated according to an example of the embodiment.

Fig. 3A is a plan view explaining the displacement of the landing position of the droplets discharged from the inkjet head caused by the tendency of the discharge angle of the liquid droplets.

FIG. 3B is a side view explaining the displacement of the landing position caused by the tendency of the ejection angle of the liquid droplets ejected from the inkjet head.

Fig. 4A is a plan view illustrating the displacement of the landing position caused by the droplet ejection angle tendency when the rotation angle of the inkjet head is 0°.

Fig. 4B is a plan view illustrating the displacement of the landing position caused by the droplet ejection angle tendency when the rotation angle of the inkjet head is φ degrees.

Fig. 5A is a plan view illustrating the landing position of droplets discharged from the inkjet head when the application target is stopped.

Fig. 5B is a side view illustrating the landing position of the droplets discharged from the inkjet head when the application target is stopped.

Fig. 6A is a plan view illustrating the landing position of droplets discharged from the inkjet head when the application target is traveling.

6B is a side view explaining the landing position of the droplets discharged from the inkjet head when the application target is traveling.

Fig. 7 is a plan view illustrating the landing position of droplets discharged when the rotation angle of the inkjet head is 0 degrees when the application target is traveling.

Fig. 8A illustrates the Y-direction positional deviation between the landing position of the ejected droplets and the coating target portion of the coating target when the rotation angle of the inkjet head is 0 degrees when the coating target is walking The plan view of the displacement.

FIG. 8B is a plan view illustrating the distance in the X direction between the landing position of the droplet discharged and the Y axis when the rotation angle of the inkjet head is 0 degrees when the application target is traveling.

FIG. 8C is a plan view illustrating the landing position when the ejection timing is corrected so that the rotation angle of the inkjet head is 0 degrees when the coating target is traveling on the Y axis.

Fig. 8D is a plan view illustrating the position of the droplet that has been printed on the coating target in a state where the ejection timing has been corrected so that the rotation angle of the inkjet head is 0 degrees and the landing position is on the Y axis. .

Fig. 8E is an enlarged view of part A of Fig. 8D.

9A illustrates the Y-direction deviation between the landing position of the ejected droplets and the coating target portion of the coating target when the rotation angle of the inkjet head is θ degrees when the coating target is walking The plan view of the displacement.

9B is a plan view illustrating the distance in the X direction between the landing position of the droplet discharged when the rotation angle of the inkjet head is θ degrees and the Y axis when the coating target is traveling.

FIG. 9C is a plan view illustrating the landing position when the ejection timing is corrected so that the rotation angle of the inkjet head is θ degrees when the coating target is traveling.

FIG. 9D is a plan view illustrating the position of the droplet when the droplet has been printed on the coated object in a state where the ejection timing has been corrected so that the rotation angle of the inkjet head is θ degrees and the landing position is on the Y axis. .

Fig. 9E is an enlarged view of part A of Fig. 9D.

Fig. 10A illustrates the Y-direction position deviation between the landing position of the ejected droplets and the coating target portion of the coating target when the rotation angle of the inkjet head is φ degrees when the coating target is walking The plan view of the displacement.

10B is a plan view illustrating the distance in the X direction between the landing position of the ejected droplets and the Y axis when the rotation angle of the inkjet head is φ _{c degrees when the coating target is traveling.}

Fig. 10C is a plan view illustrating the landing position when the ejection timing is corrected so that the rotation angle of the inkjet head is φ _{c degrees when the coating target is traveling.}

Fig. 10D illustrates the position of the droplet that has been applied to the coating target when the ejection timing has been corrected so that the rotation angle of the inkjet head is φ _{c degrees and the landing position is on the Y axis.} Floor plan.

Fig. 10E is an enlarged view of part A of Fig. 10D.

FIG. 11 is a plan view illustrating the position of the ink jet head before and after the rotation of θ degrees when the coated object is scanned at a speed of V. FIG.

Fig. 12 is a plan view illustrating the landing position when the inkjet head is rotated by φ when the coating target is scanned at a speed V.

Fig. 13 is a plan view illustrating the landing position of the inkjet head before and after the rotation of θ degrees when the coating object is stopped.

FIG. 14A is a diagram for explaining how the inkjet head is adjusted to match the pitch of the application target portion of the application object in the conventional example.

FIG. 14B is a diagram illustrating a case where the inkjet head is adjusted to match the pitch of the application target portion of the application object in the conventional example.

15 is a flowchart for adjusting the pitch of the application target portion of the application target and the pitch of the droplets discharged from the inkjet head in the past example.

1: substrate

2: Substrate adsorption table

3: Substrate rotation mechanism

4: Substrate conveying slide

5: Rails for substrates

6: Linear motor for substrate transfer

7: Board conveying position detection unit

8: Inkjet head

9: Head bracket

10: Head rotating mechanism

11: Bracket

12: Slider for head unit transfer

13: Guide rail for head unit transfer

14: Linear motor for head unit transfer

15: Position detection unit for head unit transfer

16: Support part

17: Platform

18: stand

21: Camera

22: Head unit base

23: Inkjet head

30: substrate transfer table

32: head unit

33: Head unit transfer table

40: Inkjet printing device

100: Inkjet head control section

110: Memory Department

120: Computing Department

V: speed

X, Y, Z: direction

Claims (7)

An inkjet printing method is an inkjet printing method in which droplets are ejected from the inkjet head while the inkjet head is relatively scanned against an object to be coated, and ink is applied to the object to be coated. The inkjet printing method includes the following steps : The first step is to read the data related to the aforementioned drop position deviation characteristic from the memory unit that memorizes the drop position deviation characteristic. The aforementioned drop position deviation characteristic is calculated based on the drop position deviation. The aforementioned drop position The positional deviation is the deviation of the landing position of the droplets discharged from the inkjet head from the target position in each of the first rotation angle and the second rotation angle of the inkjet head that are different from each other; The second step is to obtain the aforementioned landing position offset characteristics, the arrangement pitch of the droplet ejection nozzles of the inkjet head, and the coating target pitch of the aforementioned coating object in a direction orthogonal to the scanning direction. The target rotation angle of the inkjet head, and generate a printing pattern corresponding to the aforementioned target rotation angle; and In the third step, based on the target rotation angle and the print pattern, the inkjet head is controlled to discharge droplets to the coating target portion on the coating target. The inkjet printing method of claim 1, wherein the drop point position deviation characteristic includes: the drop point position deviation amount caused by the droplet ejection angle tendency of the droplet ejection nozzle of the inkjet head, and the droplet position deviation amount associated with the inkjet head The offset of the landing position of the scan. Such as the inkjet printing method of claim 1 or 2, which further includes: In the fourth step, when the inkjet head is at the target rotation angle, the offset is calculated. The offset is in a direction orthogonal to the scanning direction of the inkjet head for aligning the inkjet head at the Coating target department, In the third step, the inkjet head is controlled to discharge droplets to the coating target portion based on the target rotation angle, the printing pattern, and the offset amount. The inkjet printing method according to any one of claims 1 to 3, wherein the aforementioned drop point position offset characteristic is obtained by the following steps A) to E), and is stored in the aforementioned memory unit, including The following steps: A) Using the normal direction of the surface of the coating object as the rotation axis, position the inkjet head to the first rotation angle, and discharge droplets according to the first printing pattern; B) detecting the displacement of the drop position of the droplet discharged in the step A) from the target position shown in the first printing pattern; C) Position the inkjet head to the second rotation angle, and eject droplets according to the second printing pattern; D) detecting the displacement of the drop point of the droplet discharged in the step of C) from the target position shown in the second printing pattern; and E) Based on the deviation of the landing position detected in the step B), the deviation of the landing position detected in the step D), and the coordinates of the rotation axis of the inkjet head, Calculate the aforementioned drop position offset characteristics. The inkjet printing method of claim 4, wherein in the third step, the relative movement speed of the inkjet head and the coating object and the inkjet head and the coating object in the step A) Under the condition that the relative moving speed of the object and the relative moving speed of the inkjet head and the application target object in the step C) become the same, droplets are discharged from the inkjet head to the application target portion. An inkjet printing device is an inkjet printing device that ejects droplets from the inkjet head while relatively scanning an inkjet head against an object to be coated, and applies ink on the object to be coated, and includes: The memory unit stores the characteristics of the positional deviation of the landing point. The characteristic of the positional deviation of the landing position is obtained from the deviation of the position of the landing position. The deviation of the landing position is the first rotation angle and the 2 For each of the rotation angles, the drop position from the target position of the droplets discharged from the aforementioned inkjet head is offset; and The arithmetic unit obtains the aforementioned landing position offset characteristics, the arrangement pitch of the droplet ejection nozzles of the aforementioned inkjet head, and the coating target pitch of the aforementioned coating target in the direction orthogonal to the scanning direction. The target rotation angle of the inkjet head, and generate a printing pattern corresponding to the aforementioned target rotation angle, Based on the target rotation angle and the printing pattern, the inkjet head is controlled to discharge droplets to the coating target portion on the coating object. Such as the inkjet printing device of claim 6, which has: A substrate suction table, which mounts a substrate corresponding to the aforementioned coating object; The substrate rotating mechanism rotatably supports the lower part of the aforementioned substrate adsorption table; A substrate transfer table, which transfers the aforementioned substrate rotating mechanism and the aforementioned substrate suction table; The substrate conveying position detection unit detects the substrate conveying position of the aforementioned substrate conveying table; The aforementioned inkjet head is arranged on the upper part of the aforementioned substrate so as to face the aforementioned substrate; A head rotation mechanism, which is arranged on the upper part of the inkjet head, and rotatably supports the inkjet head with the normal direction relative to the plane of the substrate as an axis; and The head transfer stage transfers the inkjet head and the head rotation mechanism in a direction orthogonal to the transfer direction of the substrate transfer stage and the direction of the rotation axis.

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