KR20210143663A - Apparatus for applying ink, device for controlling the same, and method for inspecting ink-jet head - Google Patents

Abstract

Provided is an apparatus for applying ink, which is able to suppress the lengthening of the time for inspecting the presence or absence of a fault in a nozzle. A moving instrument places a substrate at a position facing a nozzle of an ink-jet head, and moves one of the ink-jet head and the substrate toward the other. A photographing apparatus photographs the surface of the substrate on which the ink is to be applied. A control apparatus moves the ink-jet head relatively to the substrate, and performs a drawing process to discharge ink from some of a plurality of nozzles. At least some of the nozzles planned to discharge ink or the nozzles which have discharged ink in the drawing process are selected as the nozzles to be inspected, and ink is discharged from the nozzles to be inspected, and a discharge process for inspection is conducted to apply ink on an area of the substrate. An image is obtained by photographing the area with the ink applied in the discharge process for inspection by the photographing apparatus, and the presence or absence of a fault in the operation of the nozzles is determined from the obtained image.

Description

Ink application device, its control device, and inkjet head inspection method

This application claims priority based on Japanese Patent Application No. 2020-088087 filed on May 20, 2020. The entire contents of the application are incorporated herein by reference.

The present invention relates to an ink application apparatus using an inkjet head, a control apparatus thereof, and an inkjet head inspection method.

A technique of forming a pattern made of ink on a substrate by discharging ink from each nozzle of an inkjet head having a plurality of nozzles toward a substrate is known. A method of detecting a nozzle defect of an inkjet head is disclosed in Patent Document 1 below.

In the method disclosed in Patent Document 1, an inspection area for drawing an inspection pattern and a real drawing area for forming a real drawing pattern are set on a drawing object. An inspection pattern is formed in the inspection area by discharging droplets from all of the plurality of nozzles. By performing image recognition of this inspection pattern, nozzle failure is detected.

Patent Document 1: Japanese Patent Application Laid-Open No. 2003-251243

In one inkjet head, for example, about 1000 nozzles may be provided. In such a case where a plurality of nozzles are provided, in order to image-recognize an inspection pattern formed by discharging ink from the plurality of nozzles for each nozzle and determine whether there is a defect, a time that cannot be ignored compared to the time of the drawing process is required. do. When an inspection pattern is formed on each of the substrates and image recognition is performed, the processing time per substrate becomes long.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an ink applying apparatus capable of suppressing the lengthening of the inspection time for defective nozzles, a control apparatus thereof, and an inkjet head inspection method.

According to one aspect of the present invention,

An inkjet head provided with a plurality of nozzles for discharging ink;

a moving mechanism for disposing a substrate at a position opposite to the nozzle of the inkjet head and moving one of the inkjet head and the substrate with respect to the other;

an imaging device for imaging the surface of the substrate on which the ink strikes;

a control device that controls the inkjet head and the moving mechanism and interprets an image captured by the imaging device;

The control device is

a drawing process of discharging ink from some of the plurality of nozzles while relatively moving the inkjet head with respect to the substrate;

At least some of the nozzles that are scheduled to eject ink in the drawing process or the nozzles that eject ink in the drawing process are selected as the nozzles to be inspected, and the ink is discharged from the nozzles to be inspected, a discharging process for inspection in which ink is not discharged from the nozzle and the ink reaches a portion of the substrate;

An ink applying apparatus is provided that acquires an image captured by the imaging device on an area where ink has landed in the discharge processing for inspection, and performs judgment processing for determining whether or not a malfunction of a nozzle is present from the acquired image.

According to another aspect of the present invention,

A control device used in the ink applying device is provided.

According to another aspect of the present invention,

Drawing a pattern made of ink by discharging ink from some nozzles among a plurality of nozzles of the inkjet head while relatively moving the inkjet head with respect to the substrate;

Before drawing the pattern, during drawing, and after drawing, at least one of the nozzles scheduled to discharge ink by drawing the pattern or at least a part of the nozzles from which ink is discharged is selected as the nozzle to be inspected. to discharge ink from a nozzle to be inspected, and not to eject ink from a nozzle that has not been inspected, and to form an inspection pattern in a part of the substrate,

An inkjet head inspection method is provided for acquiring an image of the inspection pattern and determining, from the acquired image, the presence or absence of malfunction of a nozzle.

The lengthening of the inspection time can be suppressed by selecting a nozzle to be inspected from all the nozzles and performing inspection on the nozzle to be inspected.

1A is a schematic front view of an ink application apparatus according to an embodiment, and FIG. 1B is a diagram showing the positional relationship of a movable table, an ink discharging unit, and an imaging device in a plan view. am.
FIG. 2 is a diagram illustrating a pattern formed on a substrate by discharging ink, and a trajectory of a relative movement of an inkjet head with respect to the substrate.
Fig. 3 is a diagram showing a pattern formed on a substrate by ejection of ink, and a trajectory of the relative movement of the imaging device with respect to the substrate.
4 is a flowchart showing a procedure for applying ink and inspecting the inkjet head.
5 is a diagram illustrating a pattern formed on a substrate by ejection of ink and a trajectory of a relative movement of an inkjet head with respect to the substrate, according to another embodiment.
FIG. 6 is a diagram showing a pattern formed on a substrate by ejection of ink, and a trajectory of a relative movement of the imaging device with respect to the substrate, in the embodiment shown in FIG. 5; FIG.
Fig. 7 is a flowchart showing a procedure for applying ink and inspecting the inkjet head according to the embodiment shown in Figs.
8 is a diagram illustrating a pattern formed on a substrate by ejection of ink, and a trajectory of a relative movement of an inkjet head with respect to the substrate, according to another embodiment.
Fig. 9 is a flowchart showing a procedure for applying ink and inspecting the ink jet head according to the embodiment shown in Fig. 8;
10 is a diagram illustrating a pattern formed on a substrate by ejection of ink, and a trajectory of a relative movement of an inkjet head with respect to the substrate, according to another embodiment.
Fig. 11 is a flowchart showing a procedure for applying ink and inspecting the inkjet head according to the embodiment shown in Fig. 10;
12 is a diagram illustrating a pattern formed on a substrate by ejection of ink, and a trajectory of a relative movement of the inkjet head with respect to the substrate, according to another embodiment.

An embodiment of the present invention will be described with reference to the drawings 1A to 4 of FIG. 1 .

Fig. 1A is a schematic front view of an ink application apparatus according to the present embodiment. The movable table 12 is supported by the moving mechanism 11 on the base 10 . An xyz orthogonal coordinate system is defined in which the x-axis and the y-axis are oriented in the horizontal direction and the z-axis is oriented vertically upward. The moving mechanism 11 is controlled by the control device 50, and moves the movable table 12 in two directions: the x-direction and the y-direction. As the moving mechanism 11, for example, an XY stage including an X-direction moving mechanism 11X and a Y-direction moving mechanism 11Y can be used. The X-direction moving mechanism 11X moves the Y-direction moving mechanism 11Y with respect to the base 10 in the x direction, and the Y-direction moving mechanism 11Y moves the movable table 12 with respect to the base 10 in y move in the direction

On the upper surface (supporting surface) of the movable table 12, the substrate 20 to which the ink is applied is supported. The substrate 20 is fixed to the movable table 12 by, for example, a vacuum chuck. The moving mechanism 11 moves the substrate 20 supported by the movable table 12 in a direction parallel to the xy plane. Above the movable table 12 , the ink discharging unit 30 and the imaging device 40 are supported by, for example, a door-shaped support member 13 . The ink discharging unit 30 and the imaging device 40 are supported so as to be able to move up and down with respect to the base 10 . The ink discharging unit 30 has a plurality of nozzles facing the substrate 20 . Each nozzle forms and discharges photocurable (for example, ultraviolet curable) ink into droplets toward the surface of the substrate 20 . The discharge of ink is controlled by the control device 50 .

The imaging device 40 images the upper surface (surface to which ink is applied) of the substrate 20 . Of the upper surface of the substrate 20 , a region located within the range of the angle of view of the imaging device 40 is imaged by the imaging device 40 .

1A in Fig. 1 shows a configuration in which the ink discharging unit 30 and the imaging device 40 are stopped with respect to the base 10 and the substrate 20 is moved in the x direction and the y direction. A configuration in which the substrate 20 is stopped with respect to (10) and the ink ejection unit 30 and the imaging device 40 are moved may be employed. Both a configuration in which the ink discharging unit 30 and the imaging device 40 are stopped and the substrate 20 is moved, and a configuration in which the substrate 20 is stopped and the ink discharging unit 30 and the imaging device 40 are moved, It can be said that the ink ejection unit 30 and the imaging device 40 are relatively moved with respect to the substrate 20 .

The control device 50 includes a storage unit 51 and a control unit 52 . In the storage unit 51, information (hereinafter, referred to as application pattern data) for designating a position where ink is to be applied is stored. For example, application|coating pattern data designates the pixel to which ink should land among the some pixel respectively corresponded to the some position on the surface of the board|substrate 20. As shown in FIG. In the present specification, a position on the substrate corresponding to a plurality of pixels of the application pattern data is simply referred to as a "pixel" in some cases.

The control unit 52 controls the moving mechanism 11 and the ink discharging unit 30 based on the application pattern data, thereby causing the ink to reach a predetermined position on the surface of the substrate 20 . As a result, dots or films made of ink are formed on the surface of the substrate 20 . A "dot" means the pattern in which the ink which arrived at one pixel is not continuous with the ink which arrived at the other pixel, but is isolated. On the other hand, a "film" means a pattern in which the ink which landed on a plurality of pixels continues and continues.

1B in FIG. 1 is a diagram showing the positional relationship of the movable table 12, the ink discharging unit 30, and the imaging device 40 in a plan view. A substrate 20 is supported on the support surface of the movable table 12 . An ink discharging unit 30 and an imaging device 40 are supported above the substrate 20 . The ink discharging unit 30 includes an inkjet head 31 and a light source 33 for curing. A plurality of nozzles 32 are provided on a surface of the inkjet head 31 facing the substrate 20 . The plurality of nozzles 32 are arranged at equal intervals in the x direction. This interval is, for example, a dimension corresponding to a resolution of 600 dpi. However, it is not necessary to arrange|position the some nozzle 32 on one straight line parallel to the x direction, and may be arrange|positioned at the position regularly shifted|deviated from the reference line parallel to the x direction in the y direction. For example, you may arrange|position in zigzag shape.

The light sources 33 for curing are disposed on both sides of the inkjet head 31 in the y direction, respectively, and function as a curing device for curing the ink adhering to the substrate 20 . The moving mechanism 11 is controlled by the control device 50 to move the movable table 12 in the x-direction and the y-direction. In addition, the control device 50 controls the ejection of ink from each nozzle 32 of the inkjet head 31 .

By discharging ink from the inkjet head 31 while moving the substrate 20 in the y direction (in other words, while moving the inkjet head 31 relative to the substrate 20 in the y direction), with respect to the x direction For example, with a resolution of 600 dpi, ink can be applied to the substrate 20 . The ink adhering to the substrate 20 is cured by the light emitted from the light source 33 for curing located on the downstream side of the moving direction of the substrate 20 . An operation in which ink hits the substrate 20 from the inkjet head 31 while moving the substrate 20 in the y direction is referred to as a “scan operation”.

In one scan operation, the inkjet head 31 may be reciprocated at least one time in the y direction. At this time, by shifting the inkjet head 31 in the x-direction with respect to the substrate 20 by 1/2 of the pitch of the nozzles 32 in the forward and backward paths, the ink can reach the substrate 20 with a resolution of 1200 dpi. have. By making the shift|offset|difference amount of the inkjet head 31 1/4 of the pitch of the nozzle 32, and making the inkjet head 31 reciprocate twice, ink can be made to reach the board|substrate 20 with the resolution of 2400 dpi. As described above, even when the inkjet head 31 is moved a plurality of times in the positive and negative directions of the y-axis in order to increase the resolution, the plurality of movements are collectively referred to as one scan operation.

The control device 50 moves the movable table 12 in the x direction when one scan operation is completed. In other words, the inkjet head 31 is relatively moved in the x direction with respect to the substrate 20 . This operation will be referred to as "shift operation". By repeating the scan operation and the shift operation, ink can be applied to the entire area of the substrate 20 . The relative movement amount of the inkjet head 31 in the x-direction with respect to the substrate 20 may be substantially equal to the distance between the two nozzles 32 positioned at both ends in the x-direction. However, when some nozzles 32 in the vicinity of both ends are not used for ink ejection, the distance between the nozzles 32 located at both ends of the nozzles 32 actually used may be substantially the same.

Next, with reference to FIGS. 2-4, the procedure of application|coating of ink (drawing) and the inspection of an inkjet head is demonstrated.

FIG. 2 is a diagram showing a pattern formed on the substrate 20 by discharging ink, and a trajectory of a relative movement of the inkjet head 31 with respect to the substrate 20 . In FIG. 2 , the trajectory of the relative movement of the inkjet head 31 with respect to the substrate 20 is indicated by a broken line with an arrow.

In the example described below, as shown in FIG. 2 , a real drawing pattern of ink is formed on the substrate 20 by performing four scanning operations. The formed real drawing pattern is comprised by the some dot 22. As shown in FIG. That is, the ink which landed on one pixel is not continuous with the ink which landed on the other pixel, but is isolated. The real drawing pattern constituted by such a plurality of dots 22 is used, for example, as a dot spacer for preventing a short circuit between two conductive films of a resistive touch panel. In the example shown in FIG. 2, the touch panel of 4 sheets is multi-faceted by the board|substrate 20 of 1 sheet. As an example, four real drawing patterns having the same distribution of dots 22 are formed on one substrate 20 . The four real drawing patterns are arranged in a matrix of two rows and two columns.

In the vicinity of the edge of the board|substrate 20, the blank area|region which is not used as a touch panel is provided. An inspection area 25 is secured in a part of this blank area. A region on the substrate 20 to which ink can be applied by one scan operation will be referred to as a pass region 21 . A plurality of path regions 21 (four path regions 21 in the present embodiment) arranged without gaps in the x-direction are defined. Each of the path regions 21 has a rectangular shape elongated in the y-direction. The inspection area 25 is arranged along one edge parallel to the x-direction of the substrate 20 and partially overlaps all the pass areas 21 .

A scan operation is performed on the plurality of path regions 21 in the positive direction of the x-axis. In the first and third scanning operations, the inkjet head 31 is moved in the positive y-axis direction with respect to the substrate 20, and in the second and fourth scanning operations, the inkjet head 31 is moved to the substrate 20 ) in the negative direction of the y-axis.

In the scanning operation, by ejecting ink from a predetermined nozzle 32 at a predetermined timing based on the application pattern data stored in the storage unit 51 (1A in Fig. 1), the seal defined in the application pattern data is A drawing pattern can be drawn. Further, in the inspection area 25 , an inspection pattern 24 composed of a plurality of dots 23 is formed. A method of forming the inspection pattern 24 will be described later.

FIG. 3 is a diagram showing a pattern formed on the substrate 20 by discharging ink, and a trajectory of the relative movement of the imaging device 40 with respect to the substrate 20 . In FIG. 3 , the trajectory of the relative movement of the imaging device 40 with respect to the substrate 20 is indicated by a straight line with an arrow.

By moving the imaging device 40 with respect to the substrate 20 along the inspection area 25 in the x direction, an image of the inspection pattern 24 can be acquired. The width of the non-uniformity in the y-direction of the plurality of dots 23 constituting the inspection pattern 24 is smaller than the dimension in the y-direction of the region within the angle of view of the imaging device 40 .

4 is a flowchart showing a procedure for applying ink and inspecting the inkjet head. The processing of each step shown in FIG. 4 is executed when the control device 50 controls the moving mechanism 11 , the inkjet head 31 , and the imaging device 40 .

Before performing the first scan operation, a nozzle 32 that is scheduled to eject ink in the first scan operation is selected as the nozzle 32 to be inspected (step S01). The selection of the nozzle 32 to be inspected can be performed based on the application pattern data stored in the storage unit 51 (1A in Fig. 1).

Next, while the inkjet head 31 is relatively moved in the positive direction of the y-axis with respect to the substrate 20, ink is discharged from all of the nozzles 32 (all of the nozzles 32) to be inspected. , an inspection pattern 24 (FIG. 2) composed of a plurality of dots 23 is formed in the inspection region 25 (step S02). The processing for forming the inspection pattern 24 will be referred to as a discharge processing for inspection. The inspection pattern 24 is set so that the ink ejected from each of the plurality of inspection object nozzles 32 is not continuous with each other on the substrate 20 and becomes isolated dots 23 .

Following the discharge processing for inspection, the first scan operation is performed to form a dot pattern in the pass region 21 . However, the movement in the positive direction of the y-axis of the inkjet head 31 with respect to the substrate 20 in the discharge processing for inspection and the y-axis of the inkjet head 31 with respect to the substrate 20 in the scanning operation The movement in the positive direction is performed continuously without interruption.

If the application of the ink to all of the pass regions 21 is not finished (step S04), a shift operation of moving the inkjet head 31 in the x direction with respect to the substrate 20 is performed (step S05). Thereafter, a scanning operation in the negative direction of the y-axis is performed to form a dot pattern in the path region 21 (step S06). Next, the nozzle 32 from which ink was ejected in the immediately preceding scanning operation (the second scanning operation) is selected as the nozzle 32 to be inspected (step S07).

Following the scanning operation, ink is discharged from all of the nozzles 32 to be inspected into the inspection region 25 overlapping the pass region 21 corresponding to the second scanning operation, and the inspection pattern 24 (Fig. 2) is formed (step S08). If the application of ink to all the path regions 21 is not finished (step S09), a shift operation in the x direction is performed (step S10). After that, the process from step S01 is repeated. The process of forming a real drawing pattern by ink on the upper surface of the substrate 20 by repeating the scan operation and the shift operation will be referred to as "drawing process".

When it is determined in step S04 or S09 that the application of ink to all the path regions 21 is completed, the imaging device 40 is moved relative to the substrate 20 to obtain an image of the inspection pattern 24 . is obtained (step S11). Thereafter, from the acquired image, judgment processing is performed to determine whether or not there is a malfunction of the nozzle 32 (step S12).

For example, the control device 50 measures the center position, planar shape, and size of each dot 23 of the inspection pattern 24 by performing image analysis. If these measurement results are within the allowable range, the operation of the nozzle 32 in which the dot 23 is formed is normal. If the operation of the nozzle 32 is normal, the planar shape of the dot 23 formed by the nozzle 32 becomes substantially circular. The evaluation of the planar shape of the dots 23 is performed, for example, based on the amount of deviation from the geometrically correct circle. Here, the "deviation amount" is, for example, the radius of the two circumferences when the distance between the two concentric circumferences becomes the minimum when the outer circumference line of the figure to be evaluated is placed between the two concentric circumferences. It can be defined as the car of What is necessary is just to define the position of the center of these two circles as the center position of the dot 23. As shown in FIG. What is necessary is just to define the magnitude|size of the dot 23 as the average value of the diameter of two circumferences, for example.

Next, the excellent effect of the above embodiment will be described.

In the above embodiment, the nozzle 32 actually used or planned to be used in the scanning operation is selected as the nozzle to be inspected, and the inspection pattern 24 (Fig. 2, 3) is formed. For this reason, compared with the case where an inspection pattern is formed by discharging ink from all the nozzles 32, the number of the dots 23 which comprise the inspection pattern 24 decreases. By reducing the number of dots 23 to be subjected to image analysis, the time required for image analysis can be shortened. As a result, it becomes possible to shorten the time required for the ink application process including the inspection.

Further, in the above embodiment, all of the plurality of dots 23 constituting the inspection pattern 24 are distributed in the y direction in a range narrower than the dimension in the y direction of the area within the angle of view of the imaging device 40, have. For this reason, all the dots 23 of the inspection pattern 24 can be imaged by only moving in the x direction without moving the imaging device 40 in the y direction with respect to the substrate 20 . For this reason, the time required for imaging of the test|inspection pattern 24 can be shortened.

Further, in the above embodiment, the discharge processing for inspection (step S02, step S08) is performed for every one of the plurality of scan operations (step S03, step S06). That is, the inspection pattern 24 is formed corresponding to each of the plurality of pass regions 21 . If the inspection result of the inspection pattern 24 corresponding to one predetermined pass region 21 is normal, it can be inferred that the ink application process to the path region 21 was normally performed. Conversely, if the inspection result of the inspection pattern 24 corresponding to one predetermined pass region 21 is abnormal, it can be inferred that the ink application process to the path region 21 is not normally performed. have.

The plurality of dots constituting the dot spacer of the resistive touch panel are usually regularly distributed vertically and horizontally, and the pitch thereof is sufficiently large compared to the pixel pitch. That is, when the actual drawing pattern to be formed is viewed in the y-direction, many dots 22 overlap and the number of pixels in which dots 22 are not arranged is sufficiently larger than the number of pixels in which dots 22 are arranged. . For this reason, the number of nozzles 32 used in one scan operation for forming the dots 22 constituting the dot spacer is sufficient compared to the total number of nozzles 32 provided in the inkjet head 31 . little. In such a case, the effect of applying the above embodiment to the inspection of the inkjet head 31 is remarkable.

Next, a modified example of the above embodiment will be described.

In the above embodiment, before or after the execution of the scanning operation, the nozzle 32 to be inspected is selected for each scan operation (steps S01 and S07). However, before starting the ink application process, a plurality of For each of the path regions 21 (FIG. 2), the nozzle 32 to be inspected may be selected.

Further, in the above embodiment, for the odd-numbered scan operation (step S03), the discharge processing for inspection is executed (step S02) before the execution of the scan operation, and for the even-numbered scan operation (step S06), the scan operation After the execution of , the discharge processing for inspection is executed (step S08). Conversely, for an odd-numbered scan operation, the inspection discharge processing may be executed after the scan operation is executed, and for an even-numbered scan operation, the inspection discharge processing may be executed before the scan operation is executed. In this case, the inspection pattern is formed in the inspection area along the upper edge of the substrate 20 shown in FIG. 2 .

In the above embodiment, the positions in the y direction of the plurality of dots 23 (FIG. 2) constituting the inspection pattern 24 are non-uniform. Even if a plurality of dots 23 are formed on one straight line parallel to the x-axis, if the neighboring dots 23 are not continuous and an isolated state can be maintained, all dots ( 23) may be formed on one straight line parallel to the x-axis.

Moreover, in the above embodiment, although the plurality of path regions 21 are arranged so that two path regions 21 (Fig. 2) adjacent in the x direction are in contact with each other, the dots 22 (Fig. 2) with respect to the x direction. ) is not arranged, the path region 21 does not need to be arranged. For example, in the example shown in FIG. 2, you may arrange|position the 2nd pass area|region 21 and the 3rd pass area|region 21 from the left with space|interval.

In addition, in the above embodiment, the direction in which the inkjet head 31 is moved with respect to the substrate 20 (y-direction) during the scanning operation (y direction) and the direction in which the plurality of nozzles 32 are arranged at equal pitches (x-direction) are orthogonal to each other. are doing As another configuration, the moving direction of the inkjet head 31 and the arrangement direction of the plurality of nozzles 32 may cross each other at an angle other than a right angle.

Next, an ink applying apparatus according to another embodiment will be described with reference to FIGS. 5 to 7 . Hereinafter, a description of the configuration common to the embodiment shown in FIGS. 1 to 4 will be omitted.

FIG. 5 is a diagram showing a pattern formed on the substrate 20 by ejection of ink, and a trajectory of a relative movement of the inkjet head 31 with respect to the substrate 20 . In FIG. 5, the trajectory of the relative movement of the inkjet head 31 with respect to the board|substrate 20 is shown with the broken line with an arrow.

In the embodiment shown in FIGS. 1 to 4 , the inspection patterns 24 ( FIG. 2 ) respectively corresponding to the plurality of pass regions 21 are all along one edge parallel to the x-axis of the substrate 20 . It is formed in the inspection area 25 . In contrast, in the embodiment shown in FIGS. 5 to 7 , two inspection areas 25 ( FIG. 5 ) are arranged along each of the two edges parallel to the x-axis of the substrate 20 . For the first and third pass regions 21 counting in the positive direction of the x-axis, the inspection pattern 24 is formed in the inspection region 25 along the edge of the positive side (upper side in Fig. 5) of the y-axis. Then, for the second and fourth pass regions 21, the inspection pattern 24 is formed in the inspection region 25 along the edge of the negative side (lower side in Fig. 5) of the y-axis. That is, the inspection pattern 24 is formed in the inspection area 25 on the downstream side in the moving direction of the inkjet head 31 in the scanning operation.

FIG. 6 is a diagram showing a pattern formed on the substrate 20 by ejection of ink, and a trajectory of the relative movement of the imaging device 40 with respect to the substrate 20 . In FIG. 6 , the trajectory of the relative movement of the imaging device 40 with respect to the substrate 20 is indicated by a broken line with an arrow.

1 to 4, since all the dots 23 of the inspection pattern 24 are distributed in the inspection area 25 along one edge parallel to the x-axis of the substrate 20, All the dots 23 can be imaged only by moving the imaging device 40 (FIG. 3) parallel to the x-axis. In contrast, in the embodiment shown in FIGS. 5 to 7 , two inspection areas 25 ( FIG. 6 ) are arranged along two edges parallel to the x-axis of the substrate 20 , respectively. For this reason, the imaging device 40 (FIG. 6) is moved along each of the inspection area 25 along one edge parallel to the x-axis of the substrate 20 and the inspection area 25 along the other edge. have to move For this reason, after imaging one test|inspection area|region 25, before imaging the other test|inspection area|region 25, it is necessary to move the imaging device 40 relatively with respect to the board|substrate 20 in the y direction.

Fig. 7 is a flowchart showing a procedure for applying ink and inspecting the inkjet head according to the present embodiment. 1 to 4, the selection of the nozzle 32 to be inspected (step S01), the discharge processing for inspection (step S02), and the scanning operation (step S03) are executed in this order. On the other hand, in the embodiment shown in Figs. 5 to 7, as shown in Fig. 7, a scanning operation (step S03), selection of the nozzle 32 to be inspected (step S01), and discharge processing for inspection (step S02) are executed in this order. That is, the discharge processing for inspection is executed after the scan operation.

Next, the excellent effect of the Example shown in FIGS. 5-7 is demonstrated.

Also in this embodiment, similarly to the embodiment shown in Figs. 1 to 4, it becomes possible to shorten the time required for the ink application process including the inspection for the presence or absence of malfunction of the nozzle 32. In addition, in this embodiment, after performing one scan operation, the inspection pattern 24 (FIG. 5) is formed using the nozzle 32 which ejected ink in the scanning operation. For this reason, although the operation was normally performed at the start of the scanning operation, it is possible to detect a malfunction of the nozzle 32 even when a failure seems to have occurred in the middle of the scanning operation.

Next, an ink applying apparatus according to another embodiment will be described with reference to FIGS. 8 and 9 . Hereinafter, a description of the configuration common to the embodiment shown in FIGS. 1 to 4 will be omitted.

8 is a diagram showing a pattern formed on the substrate 20 by ejection of ink, and a trajectory of a relative movement of the inkjet head 31 with respect to the substrate 20 . In FIG. 8, the trajectory of the relative movement of the inkjet head 31 with respect to the board|substrate 20 is shown with the broken line with an arrow.

1 to 4 , for each of the plurality of pass regions 21 , the inspection pattern 24 ( FIG. 2 ) is formed in the inspection region 25 overlapping the path region 21 . On the other hand, in the present embodiment, the inspection pattern 24 is in a range overlapping the pass region 21 (the leftmost path region 21 in Fig. 8) to which ink is applied in the first scan operation among the inspection regions 25. , and no inspection pattern is formed in a range overlapping with the other pass regions 21 . This inspection pattern 24 selects, as the nozzle 32 of the inspection object, a nozzle 32 that is to discharge ink in at least one scanning operation among all the scanning operations, and injects ink from the nozzle 32 of the inspection object. It is formed by discharging. That is, one inspection pattern 24 is formed corresponding to all of the plurality of scan operations.

Fig. 9 is a flowchart showing a procedure for applying ink and inspecting the inkjet head according to the present embodiment. First, in at least one scanning operation among all the scanning operations, a nozzle 32 that is scheduled to discharge ink is selected as the nozzle 32 to be inspected (step S21). The discharge processing for inspection is performed with respect to the nozzle 32 of an inspection object (step S22). Specifically, the inspection pattern 24 is formed in a region where the leftmost pass region 21 and the inspection region 25 in FIG. 8 overlap.

After the inspection pattern 24 is formed, a drawing process of applying ink to all the path regions 21 is performed by repeating a scan operation and a shift operation (step S23). When the drawing process is finished, the inspection pattern 24 is imaged by the imaging device 40, and an image of the inspection pattern 24 is acquired (step S24). Thereafter, from the acquired image, the presence or absence of the malfunctioning nozzle 32 is determined (step S25).

Next, the excellent effect of the Example shown in FIGS. 8-9 is demonstrated.

In the embodiment shown in Figs. 1 to 4, the inspection pattern 24 (Fig. 2) is formed for each scan operation, and image analysis of the inspection pattern 24 is performed. When ink is discharged from the same nozzle 32 in a plurality of scanning operations, the nozzle 32 forms a dot 23 (FIG. 2) in each of the plurality of inspection patterns 24. As shown in FIG. Image analysis is performed on the dots 23 included in each of the plurality of inspection patterns 24 . That is, a plurality of times of inspection are performed with respect to one nozzle 32 .

In contrast, in the embodiment shown in Figs. 8 to 9, one dot 23 is formed in one inspection pattern 24 with respect to the nozzles 32 that ejected ink in a plurality of scanning operations. For this reason, in the application of ink to the substrate 20, the plurality of nozzles 32 from which the ink is ejected are inspected once, and there is no case where a plurality of inspections are performed for one nozzle 32. . Thereby, the inspection time can be shortened.

Next, a modified example of the embodiment shown in Figs. 8 to 9 will be described.

In the embodiment shown in Figs. 8 to 9, the discharge processing for inspection (step S22) is performed once for all scan operations. On the other hand, the discharge processing for inspection may be performed once for a plurality of scan operations in some of all the scan operations. For example, in the example shown in Fig. 8, one inspection ejection process is performed for the first and second scan operations, and one inspection ejection process is performed for the third and fourth scan operations. You can do it. In this case, the overlapping area of the pass area 21 and the inspection area 25 corresponding to the first scan operation, and the overlapping area of the pass area 21 and the inspection area 25 corresponding to the third scanning operation The inspection pattern 24 may be formed.

Next, an ink application apparatus according to another embodiment will be described with reference to FIGS. 10 and 11 . Hereinafter, a description of the configuration common to the embodiment shown in FIGS. 8 to 9 will be omitted.

FIG. 10 is a diagram showing a pattern formed on the substrate 20 by discharging ink, and a trajectory of the relative movement of the inkjet head 31 with respect to the substrate 20 . In FIG. 10 , the trajectory of the relative movement of the inkjet head 31 with respect to the substrate 20 is indicated by a broken line with an arrow.

In the embodiment shown in Figs. 8 to 9, the inspection pattern is formed in the overlapping region between the pass region 21 (the left end path region 21 in Fig. 8) and the inspection region 25 corresponding to the scan operation to be performed first. (24) (Fig. 8) is formed. On the other hand, in the present embodiment, the inspection pattern 24 ( 8) is formed.

11 is a flowchart showing a procedure for applying ink and inspecting the inkjet head according to the present embodiment. In the embodiment shown in Figs. 8 to 9, as shown in Fig. 9, after the discharge processing for inspection (step S22) is performed, the scan operation and the shift operation are repeated (step S23). On the other hand, in the present embodiment, as shown in Fig. 11, after repeating the scanning operation and the shifting operation (step S23), extraction of the nozzle 32 to be inspected (step S21), and discharge processing for inspection (step S23) S22) is performed. However, the extraction of the nozzle 32 to be inspected may be performed before repetition of the scan operation and the shift operation (step S23).

Next, the excellent effect of the Example shown in FIGS. 10-11 is demonstrated.

In the embodiment shown in Figs. 10 to 11, similarly to the embodiment shown in Figs. 8 to 9, the inspection time can be shortened. In addition, in this embodiment, the discharge processing for inspection (step S22) is performed after all scanning operations are finished. For this reason, when an abnormality occurs in the nozzle 32 in the middle of a certain scan operation, the abnormality can be detected. If no abnormality is found in the inspection (step S25) of the inspection pattern 24 (Fig. 10), it can be inferred that the ink application process performed on the substrate 20 was normal.

Next, an ink applying apparatus according to another embodiment will be described with reference to FIG. 12 . Hereinafter, a description of the configuration common to the embodiment shown in FIGS. 1 to 4 will be omitted.

12 is a diagram illustrating a pattern formed on the substrate 20 by ejecting ink, and a trajectory of a relative movement of the inkjet head 31 with respect to the substrate 20 . In FIG. 12 , the trajectory of the relative movement of the inkjet head 31 with respect to the substrate 20 is indicated by a broken line with an arrow.

In the embodiment shown in Figs. 1 to 4, a real drawing pattern composed of only a plurality of dots 22 ( Fig. 2 ) is formed on the substrate 20 . That is, the upper surface of the board|substrate 20 WHEREIN: The ink which landed on one pixel is isolated without continuing with the ink which landed on the other pixel. On the other hand, in this embodiment, in addition to the plurality of dots 22, a film 26 of ink is formed. The film|membrane 26 is formed by mutually continuing the ink which reached each of a some pixel. In order to form the film 26, ink is usually ejected from all of the nozzles 32 passing through the region where the film 26 is disposed during a scanning operation.

In the case of forming the plurality of dots 22 and the film 26 on one substrate 20, if a nozzle 32 for discharging ink for forming the film 26 is included in the inspection object, the inspection object The number of nozzles 32 of the will increase remarkably. In the present embodiment, a nozzle 32 that has ejected ink to form dots 22 or is scheduled to eject ink is an inspection object, and a nozzle that ejects ink only to form a film 26 ( 32) is not subject to inspection. For this reason, the dot 23 of the test|inspection pattern 24 is not formed in the area|region 27 in which only the film|membrane 26 is arrange|positioned, and the dot 22 is not arrange|positioned as seen in the y direction.

Next, the excellent effect of this embodiment is demonstrated.

When the nozzles 32 from which ink is ejected to form the film 26 are used as the inspection object, the number of the nozzles 32 to be inspected becomes excessively large. For this reason, as compared with the method of inspecting all the nozzles 32, a meaningful effect of shortening the inspection time may not be obtained. In the embodiment shown in Fig. 12, the nozzle 32 that ejects ink only for forming the film 26 without ejecting the ink for forming the dots 22 is excluded from the inspection object. For this reason, it can suppress that the number of objects of the nozzle 32 of an inspection object increases excessively. As a result, a sufficient effect of shortening the inspection time is obtained.

However, in the film 26, the inks that land on the pixels in the predetermined area are formed in succession with each other. For this reason, even if the operation|movement of one nozzle 32 is defective, the pixel which the ink from the defective nozzle 32 is going to land on is filled by diffusion of the ink discharged from the other normal nozzle 32. For this reason, in the formation of the film 26, malfunction of one or a small number of nozzles 32 may be tolerated. Accordingly, even if the nozzle 32 that discharges the ink for forming the film 26 is not inspected, the quality of the film 26 is guaranteed to some extent.

Next, a modified example of the embodiment shown in Fig. 12 will be described.

In the embodiment shown in Fig. 12, discharging the ink for forming the plurality of dots 22 is an extraction condition of the nozzle 32 to be inspected, and discharging the ink for forming the film 26 is , it is not set as the extraction condition of the nozzle 32 to be inspected. Depending on the shape and dimensions of the film 26 , it may be preferable to inspect at least a part of the nozzle 32 forming the film 26 , similarly to the nozzle 32 forming the dot 22 . . For example, in the case of forming a band-like film having a width corresponding to one pixel, it is preferable to include a nozzle 32 for discharging the ink forming the film in the inspection object.

In this way, in the selection of the nozzle to be inspected, not only the dots 22 are paid attention, but at least some of the nozzles that are scheduled to eject ink in the drawing process or the nozzles that eject the ink in the drawing process are selected as the target of the inspection. What is necessary is just to select it as a nozzle. When the nozzle 32 to be inspected is selected, the nozzle 32 for forming the dots 22 may be included in the inspection object without fail. Regarding the nozzle 32 that is not used to form the dots 22 and is used to form the film 26 , it may be determined whether or not to be included in the inspection object based on the shape and size of the film 26 . However, at least some of the nozzles from which ink is ejected in the drawing process or the nozzles that eject ink in the drawing process are selected as the nozzles to be inspected, and at least a part of the nozzles not related to the drawing process are additionally inspected. You may select as a target nozzle.

Each of the above-described embodiments is an example, and it goes without saying that partial substitutions or combinations of configurations shown in other embodiments are possible. For the same operation and effect by the same configuration of the plurality of embodiments, it is not mentioned for each embodiment one by one. In addition, the present invention is not limited to the above-described embodiment. For example, it will be apparent to those skilled in the art that various modifications, improvements, combinations, and the like are possible.

10 anticipation
11 moving mechanism
11X X direction movement mechanism
11Y Y direction movement mechanism
12 movable table
13 support member
20 board
21 pass area
22 dots
23 Dot of inspection pattern
24 inspection pattern
25 inspection area
26 act
Area where only the 27 Acts are placed
30 Ink discharge unit
31 inkjet head
32 nozzles
33 light source for curing
40 imaging device
50 control
51 memory
52 control

Claims (19)

An inkjet head provided with a plurality of nozzles for discharging ink;
a moving mechanism for disposing a substrate at a position opposite to the nozzle of the inkjet head and moving one of the inkjet head and the substrate with respect to the other;
an imaging device for imaging the surface of the substrate on which the ink strikes;
a control device that controls the inkjet head and the moving mechanism and interprets an image captured by the imaging device;
The control device is
a drawing process of discharging ink from some of the plurality of nozzles while relatively moving the inkjet head with respect to the substrate;
At least some of the nozzles that are scheduled to eject ink in the drawing process or the nozzles that eject ink in the drawing process are selected as the nozzles to be inspected, and the ink is discharged from the nozzles to be inspected, a discharging process for inspection in which ink is not discharged from the nozzle and the ink reaches a portion of the substrate;
An ink application apparatus which acquires an image which imaged the area|region where ink has landed by the said imaging device in the said discharge process for said inspection, and performs judgment processing which judges the presence or absence of malfunction of a nozzle from the acquired image. According to claim 1,
In the drawing process, the pattern made of the ink formed on the substrate includes a plurality of dots in which the ink respectively ejected from the plurality of nozzles is isolated on the substrate and does not connect with the ink ejected from other nozzles,
The control device is an ink applying device for selecting a nozzle scheduled to be used for formation of the plurality of dots or a nozzle used for formation of the plurality of dots as a nozzle to be inspected in the inspection ejection process. 3. The method of claim 1 or 2,
The plurality of nozzles are arranged side by side in a first direction,
The control device is
In the drawing process, a scanning operation for discharging ink while relatively moving the inkjet head in a second direction intersecting the first direction with respect to the substrate; and moving the inkjet head with respect to the substrate in the first direction An ink application device that repeats a shift operation to move it. 4. The method of claim 3,
The control device executes the inspection ejection process for each repeated scan operation, and in the inspection ejection process, selects a nozzle scheduled to eject ink in a corresponding scan operation, or a nozzle that ejected ink. An ink application device selected as a nozzle to be inspected. 5. The method of claim 4,
and the control device executes the discharging process for inspection after a corresponding scan operation before performing a next scan operation. 4. The method of claim 3,
The control device executes the inspection ejection processing once in response to a plurality of scan operations among the repeated scanning operations, and in the inspection ejection processing, a nozzle scheduled to eject ink in a plurality of corresponding scan operations. , or an ink application device that selects a nozzle that has ejected ink as a nozzle to be inspected. 4. The method of claim 3,
The control device is an ink applying device that, in the discharging process for inspection, hits the ink in a range narrower than a dimension of a region within an angle of view of the imaging device with respect to the second direction. 3. The method of claim 1 or 2,
The control device is an ink applying device configured to form an inspection pattern in which the inks respectively ejected from a plurality of nozzles are isolated from each other without being continuous on the substrate in the inspection ejection process. 9. The method of claim 8,
The control device is an ink applying device that, in the judgment processing, judges the presence or absence of malfunction of the nozzle based on the position of the ink that has landed on the substrate, and the shape and size in a planar view. An inkjet head provided with a plurality of nozzles for discharging ink;
a moving mechanism for disposing a substrate at a position opposite to the nozzle of the inkjet head and moving one of the inkjet head and the substrate with respect to the other;
As a control device for an ink application device provided with an imaging device for imaging a surface on which the ink hits the substrate,
Controlling the plurality of nozzles to discharge ink,
Controlling the moving mechanism to relatively move the inkjet head with respect to the substrate,
Analyze the image captured by the imaging device,
a drawing process of discharging ink from some of the plurality of nozzles while relatively moving the inkjet head with respect to the substrate;
At least some of the nozzles that are scheduled to eject ink in the drawing process or the nozzles that eject ink in the drawing process are selected as the nozzles to be inspected, and the ink is discharged from the nozzles to be inspected, a discharging process for inspection in which ink is not discharged from the nozzle and the ink reaches a portion of the substrate;
A control device that acquires an image obtained by capturing an area in which ink has landed by the imaging device in the discharge processing for inspection, and performs judgment processing for determining whether or not a malfunction of a nozzle is present from the acquired image. 11. The method of claim 10,
In the drawing process, the pattern made of the ink formed on the substrate includes a plurality of dots in which the ink respectively ejected from the plurality of nozzles is isolated on the substrate and does not connect with the ink ejected from other nozzles,
In the discharge processing for inspection, a nozzle scheduled to be used for formation of the plurality of dots or a nozzle used for formation of the plurality of dots is selected as a nozzle to be inspected. 12. The method of claim 10 or 11,
The plurality of nozzles are arranged side by side in a first direction,
In the drawing process, a scanning operation for discharging ink while relatively moving the inkjet head in a second direction intersecting the first direction with respect to the substrate; and moving the inkjet head with respect to the substrate in the first direction A control device that repeats the shift operation to move. 13. The method of claim 12,
The inspection ejection process is executed for each repeated scan operation, and in the inspection ejection process, a nozzle scheduled to eject ink in a corresponding scan operation or a nozzle that ejected ink is selected as a nozzle to be inspected. Control device to be selected as . 14. The method of claim 13,
A control device for executing the discharging process for inspection after a corresponding scan operation, before performing a next scan operation. 13. The method of claim 12,
Among the repeated scanning operations, the inspection ejection process is executed once in response to a plurality of scan operations, and in the inspection ejection process, a nozzle or ink to which ink is to be ejected in the corresponding plurality of scan operations is ejected A control device that selects one nozzle as a nozzle to be inspected. 13. The method of claim 12,
In the discharging process for inspection, the control device for landing ink in a range narrower than a dimension of a region within an angle of view of the imaging device in the second direction. 12. The method of claim 10 or 11,
In the discharging process for inspection, a control device for forming an inspection pattern in which inks respectively ejected from a plurality of nozzles are isolated from each other without being continuous on the substrate. 18. The method of claim 17,
A control device for determining the presence or absence of malfunction of a nozzle in the judgment processing, based on the position of the ink that has landed on the substrate, and the shape and size in a planar view. Drawing a pattern made of ink by discharging ink from some nozzles among a plurality of nozzles of the inkjet head while relatively moving the inkjet head with respect to the substrate;
Before drawing the pattern, during drawing, and after drawing, at least one of the nozzles scheduled to discharge ink by drawing the pattern or at least a part of the nozzles from which ink is discharged is selected as the nozzle to be inspected. to discharge ink from a nozzle to be inspected, and not to eject ink from a nozzle that has not been inspected, and to form an inspection pattern in a portion of the substrate,
An inkjet head inspection method for acquiring an image of the inspection pattern, and determining the presence or absence of a malfunction of a nozzle from the acquired image.

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