JP2020157280A - Droplet amount measurement system - Google Patents

Abstract

To provide means which quickly and accurately measures a droplet amount of each droplet discharged from plural ink jet nozzles.SOLUTION: A droplet amount measurement system, which measures a droplet amount of each droplet discharged from plural ink jet nozzles provided on an ink jet coating device for impacting droplets at a prescribed position on a substrate, comprises a measurement substrate holding part, a reference nozzle, a relative movement part, a reference droplet amount measurement part, a substrate transport part, a host computer, an image acquisition part, and a droplet amount measurement part. The droplet amount measurement part comprises: a droplet area measurement part which measures an area of each droplet in an image; a conversion coefficient registration part which previously registers an area volume conversion coefficient for conversion of a droplet amount of each droplet; a correction coefficient registration part which registers a wettability correction coefficient; a conversion coefficient calculation part which calculates the area volume conversion coefficient; a correction coefficient calculation part which calculates the wettability correction coefficient; and a droplet amount calculation part which calculates a droplet amount of each droplet from the area of each droplet, the area volume conversion coefficient, and the wettability correction coefficient.SELECTED DRAWING: Figure 5

Description

The present invention relates to a system for measuring the amount of each droplet ejected from a plurality of inkjet nozzles.

For the wiring of color filters and printable electronics of a liquid crystal display, a coating film or wiring having a predetermined pattern is formed by drying droplets coated in a desired pattern using an inkjet or a dispenser.

Then, there is a demand for further uniform film thickness of the coating film and wiring after the coated droplets are dried. For that purpose, it is required to accurately grasp the amount of droplets ejected from the inkjet nozzle so that the desired amount of droplets can be ejected.

Generally, a large number of inkjet nozzles are provided in one head, but it is known that the ejection amount of each of them varies and the ejection amount changes with time, and the droplets are droplets. Various techniques for accurately measuring the amount have been proposed (for example, Patent Documents 1 and 2).

Japanese Unexamined Patent Publication No. 2004-148180 Japanese Unexamined Patent Publication No. 2011-136307

In the technique of individually measuring the ejection amount (that is, the volume) of a large number of inkjet nozzles provided in one head, the droplet amount of each droplet can be accurately measured, but there is a problem that it takes time. Therefore, if the operation of the coating device is prioritized in mass production, the discharge amount measurement within the mass production operation period is avoided, and the discharge amount can be measured only during the maintenance period in which the stop time is relatively long. If the span from the last measurement to the next measurement is long, the amount of droplets will gradually become inaccurate.

On the other hand, when the liquid drop amount (volume) is calculated from the area of the landed droplets, a plurality of droplets can be imaged at one time to calculate the liquid drop amount, so that the liquid drops are ejected from a large number of inkjet nozzles. The liquid drop amount of each droplet can be measured in a short time. Therefore, the amount of liquid droplets can be measured by utilizing a small amount of free time such as the standby time within the operating period of the coating device (for example, the clearance time between coating operations), so that the measurement can be performed frequently. it can. However, if the wettability of the surface on which the droplets land is not uniform, the contact angle of each droplet will vary, and the area of the imaged droplet will differ even with the same amount of droplet (volume) (that is, from the area). The volume could not be calculated uniquely), and there was a problem of lack of accuracy.

Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to provide a means for quickly and accurately measuring the amount of each droplet ejected from a plurality of inkjet nozzles.

In order to solve the above problems, one aspect of the present invention is
It is a liquid drop amount measuring system that measures the amount of each droplet ejected from a plurality of inkjet nozzles provided in an inkjet coating device that lands a droplet at a predetermined position on a substrate.
A measurement substrate holding unit that holds a measurement substrate for landing each droplet ejected from a plurality of inkjet nozzles for which the amount of droplets is to be measured,
A reference nozzle that ejects a reference droplet that serves as a reference for measuring the amount of each droplet toward the measurement substrate,
A relative moving part that moves the measurement board and the reference nozzle relative to each other,
A reference droplet amount measuring unit that measures the droplet amount of the reference droplets ejected from the reference nozzle,
A substrate transfer unit that delivers the measurement substrate to the inkjet coating device,
A host computer that passes information on the landing position of each droplet landed on the measurement substrate to the inkjet coating device.
An image acquisition unit that acquires an image including each droplet and a reference droplet ejected from a plurality of inkjet nozzles landed on a measurement substrate.
It is provided with a droplet amount measuring unit that measures the amount of each droplet contained in the image by measuring the area of each droplet and then performing volume conversion.
The liquid drop measurement unit
A droplet area measuring unit that measures the area of each droplet contained in the image,
A conversion coefficient registration unit that pre-registers an area-volume conversion coefficient for converting the amount of each droplet that has landed on the measurement substrate from the area of each droplet.
A correction coefficient registration unit for registering a wettability correction coefficient for correcting the area of each droplet measured by the droplet area measurement unit for each location or section of the measurement substrate.
A conversion coefficient calculation unit that calculates the area volume conversion coefficient based on the relationship between the area of the reference droplet landed on the measurement substrate and the amount of the droplet,
A correction coefficient that calculates the wettability correction coefficient based on the ratio of the area of each reference droplet of the same amount of droplets landed on multiple locations on the measurement substrate to the area of the reference droplets landed on the representative location. Calculation unit and
It is provided with a droplet amount calculation unit that calculates the droplet amount of each droplet based on the area of each droplet measured by the droplet area measurement unit, the area volume conversion coefficient, and the wettability correction coefficient. It is a feature.

According to the above-mentioned droplet amount measurement system, the droplet amount of each droplet ejected from a plurality of inkjet nozzles can be measured quickly and accurately.

It is the schematic which shows the whole structure of the example of the form which embodies the present invention. It is a perspective view which shows the main part of an example of the form which embodies the present invention. It is the schematic which shows the whole structure of the example of the form which embodies the present invention. It is a perspective view which shows another main part of an example of the form which embodies the present invention. It is a top view which shows the landing example of the liquid drop in the example of the form which embodies the present invention. It is a flow figure in an example of the form which embodies the present invention. It is a flow figure in an example of the form which embodies the present invention. It is a flow figure in an example of the form which embodies the present invention. It is a flow figure in an example of the form which embodies the present invention. It is the schematic which shows the whole structure of the example of the 2nd form which embodies the present invention. It is the schematic which shows the whole structure of the example of the 2nd form which embodies the present invention. It is the schematic which shows the whole structure of the example of the 3rd form which embodies the present invention. It is the schematic which shows the whole structure of another example of the 3rd form which embodies the present invention.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

In the following description, the three axes of the Cartesian coordinate system are expressed as X, Y, and Z, the horizontal direction is expressed as the X direction and the Y direction, and the direction perpendicular to the XY plane (that is, the gravity direction) is expressed as the Z direction. To do. Further, in the Z direction, the direction against gravity is expressed as upper, and the direction in which gravity acts is expressed as lower.

[First form]
FIG. 1 is a schematic view showing an overall configuration of an example of a form embodying the present invention. FIG. 1 shows a schematic view of a droplet amount measuring device 1 according to the present invention and an inkjet coating device K provided with the device 1.

The inkjet coating device K ejects droplets (hereinafter, simply referred to as “droplets”) L of the coating liquid from a plurality of inkjet nozzles Jn toward the substrate W, and land the droplets L at predetermined positions. By letting the substrate W perform a predetermined coating operation. A mode in which a predetermined coating operation is performed on the substrate W is referred to as a "coating mode". The substrate W is handled by a substrate transfer robot RH or a conveyor installed outside, and is transferred to the inside and outside of the inkjet coating device K.

Further, the inkjet coating device K ejects the droplet L from the plurality of inkjet nozzles J toward the substrate W, the measurement surface 3 (details will be described later), and the like, and each droplet QMn in a state where the droplet L has landed. It has a "droplet amount measurement mode" in which each area SMn is measured and the droplet amount (that is, volume) V of each of the plurality of inkjet nozzles J is calculated. Then, the inkjet coating device K operates by switching between the "coating mode" and the "droplet amount measuring mode".

In the following description, the symbols "n" indicating the array addresses (addresses) are individually added to the plurality of inkjet nozzles J, the droplet L, the droplet amount V, and the like, and the inkjet nozzle Jn, the droplet Ln, and the droplets are added. It may be expressed as a quantity VMn or the like.

Specifically, the inkjet coating device K includes a substrate holding unit H, a ejection unit N, a relative moving unit M, a processing unit C1, a control unit C2, and the like, and a droplet amount measuring device 1.

The substrate holding portion H holds the substrate W.

Specifically, the substrate holding portion H has a configuration in which the substrate W is supported from the lower surface side in a horizontal state and is held so as not to be displaced. More specifically, the substrate holding portion H is mounted on the frame f of the coating device 1 with its upper surface horizontal. Further, grooves and pores are provided on the upper surface of the substrate holding portion H, and these grooves and pores are connected to a negative pressure generation source via a switching valve (not shown). Then, by operating the switching valve based on the control signal from the control unit C2, these grooves and pores are brought into a negative pressure state to attract and hold the substrate W, or the substrate W is released from the negative pressure state to atmospheric pressure to release the substrate. The adsorption of W can be released.

The discharge unit N sequentially discharges a plurality of liquid drops L toward the substrate W and the measurement surface 3.

Specifically, the discharge unit N includes a plurality of inkjet nozzles Jn. Each of the plurality of inkjet nozzles Jn independently ejects the droplet L or supplies the coating liquid from the discharge liquid supply tank 13 based on the control signal from the control unit C2. A pipe 15 connected to the liquid discharge port 14 is connected to the liquid discharge tank 13, and a switching valve 16 is attached in the middle of the pipe 15. Therefore, the discharge liquid supply tank 13 has a configuration capable of maintaining the inside thereof at a predetermined pressure (positive pressure to negative pressure).

FIG. 2 is a perspective view showing a main part of an example of a mode embodying the present invention, and FIG. 2 shows a state in which the discharge unit N is looked up obliquely upward from below.

Specifically, the ejection unit N has a plurality of inkjet nozzles Jn (for example, n = 10-12, 20-22, ..., 80-82 as shown) for ejecting the droplet L. There is. Each nozzle Jn is individually connected to a droplet ejection mechanism (not shown) provided inside the main body of the ejection unit N. More specifically, a liquid drop ejection mechanism that ejects droplet Ln by changing the volume of a piezo valve or the like can be exemplified. Then, each droplet ejection mechanism has a configuration capable of switching control such that droplet Ln is ejected / not ejected from each nozzle Jn based on the control signal output from the control unit C2. Therefore, each nozzle Jn is applied with a predetermined drive current / voltage for a predetermined time as a control signal output from the control unit C2, so that the magnitude of the drive current and the voltage, the application time Ts, and the number of times of application are applied. An amount of droplets proportional to is ejected.

Note that FIG. 2 shows a state in which the droplet Ln is ejected from a plurality of inkjet nozzles Jn (n = 10, 20, -80, etc.).

Then, the discharge unit N discharges the droplet Ln from each nozzle Jn toward a predetermined position set on the substrate W while moving relative to the substrate W, so that a predetermined coating operation is performed.

The relative moving unit M moves the ejection unit N, the flying object imaging unit 21 (details will be described later), and the image capturing camera 41 of the image acquisition unit 4 relative to the substrate W and the measurement surface 3 at a predetermined speed to determine a predetermined value. It is to be stationary at the position of.

Specifically, the moving mechanism M includes a rail portion M1, a slider portion M2, a first gantry portion M3, a rail portion M4, a slider portion M5, a second gantry portion M6, and the like, and includes an upper surface of the substrate W (that is, an XY plane). ) Is relative to the direction parallel to (for example, the Y direction).

The rail portion M1 has a predetermined length in the Y direction, and a pair of rails (that is, a pair) are horizontally mounted on the frame f of the inkjet coating device 1 in a state of being parallel to each other.

The slider portion M2 is movably mounted on the rail portion M1 and moves on the rail portion M1 in the Y direction at a predetermined speed or stands still at a predetermined position based on the control signal from the control unit C2. It is configured to do.

The first gantry section M3 is a portal structure attached to the slider section M2 so as to straddle the substrate holding section H and the measurement surface 3 in a substantially inverted U shape, and is discharged to the first gantry section M3. A unit N and a lighting unit 25 are attached.

The rail portion M4 has a predetermined length in the Y direction, and a pair of rails (that is, a pair) are horizontally mounted on the frame f of the inkjet coating device 1 in a state of being parallel to each other.

The slider portion M5 is movably mounted on the rail portion M4, and is moved on the rail portion M4 in the Y direction at a predetermined speed or stationary at a predetermined position based on the control signal from the control unit C2. It is configured to do.

The second gantry portion M6 is a portal structure attached to the slider portion M5 so as to straddle the substrate holding portion H and the measurement surface 3 in a substantially inverted U shape. The image pickup camera of the flying object imaging section 21 and the image pickup camera 41 of the image acquisition section 4 are attached to the second gantry section M6.

FIG. 3 is a schematic view showing an overall configuration of an example of a form embodying the present invention. FIG. 3 shows a state after the slider M2 shown in FIG. 1 has moved from the original position (P1) to another place (P2) and the slider M5 has moved from the original position (P4) to another place (P5). It is shown.

Further, the moving mechanism M moves the slider M2 in the predetermined section P3 at a constant speed in the "coating mode", or in the "reference droplet amount measuring mode" or the "droplet amount measuring mode" described in detail later. The slider M2 can be moved / stopped at predetermined positions P1, P2 and the like, and the slider M5 can be moved / stopped at predetermined positions P4, P5 and the like.

Since the moving mechanism M has such a configuration, the lower surface side on which the plurality of inkjet nozzles Jn of the ejection unit N are arranged, the substrate W held by the substrate holding portion H, and the upper surface of the measurement surface 3 The discharge unit N can be moved in the Y direction (that is, the scanning direction) with respect to the substrate W and the measurement surface 3 while facing each other.

The processing unit C1 performs image processing, arithmetic processing, and the like according to a procedure registered in advance.

Specifically, the processing unit C1 has the functions as described below.
-Image processing is performed on the acquired images P and Ps, and the outline of the detection target (droplet) is extracted.
-Count how many pixels the area surrounded by the contour extracted by the binarization process, the sub-pixel process, etc. is.
-The area of the area surrounded by the extracted contour is calculated from the area per pixel of the acquired images P and Ps.
-As a result obtained by image processing or calculation processing, predetermined calculation processing is performed based on pre-registered coefficients, mathematical formulas, and the like.

More specifically, the processing unit C1 is composed of a computer CN having an image processing function, an image processing device GP (that is, hardware), and an execution program (software) thereof.

The control unit C2 controls the substrate holding unit H, the ejection unit N, the relative moving unit M, the processing unit C1, the droplet amount measuring device 1, and the devices of each unit.

Specifically, the control unit C2 has the functions as described below.
-A command (signal output) is given to the substrate holding portion H to hold / release the suction.
-A command to eject the droplet L is given to each of the inkjet nozzles Jn of the ejection unit N.
-Move / stop commands are given to the slider units M2 and M5 of the relative movement unit M.
-Exchange data and signals with the processing unit C1.
-The image acquisition trigger is output to the image acquisition unit 4.
-A trigger for starting measurement is output to the droplet amount measuring unit 5.

More specifically, the control unit C2 is composed of a programmable logic controller, a computer CN, etc. (that is, hardware) and its execution program (that is, software), and signals and data output from the devices of each unit. Is input, predetermined arithmetic processing and the like are performed, and signals and data can be output to the devices of each part based on the processing result.

[About the liquid drop measuring device]
The droplet amount measuring device 1 measures the droplet amount VMn of each droplet Ln ejected from the plurality of inkjet nozzles Jn.

Specifically, the droplet amount measuring device 1 includes a reference droplet amount measuring unit 2, a measuring surface 3, an image acquisition unit 4, a droplet amount measuring unit 5, and the like. More specifically, the droplet amount measuring device 1 measures the area SMn of each droplet QMn landed on the measurement surface 3 using the above-mentioned inkjet coating device K, and each droplet QMn is derived from the measured area SMn. The volume VMn of the above is calculated (that is, the amount of liquid drops is measured). The liquid drop before landing on the measurement surface 3 is called "discharged liquid drop Ln", and the liquid drop after landing on the measurement surface 3 is called "landed liquid drop QMn". Further, the "area SMN" means an area projected on a horizontal plane parallel to the measurement surface 2 (that is, a horizontally projected area). Then, the droplet amount VMn measured by the droplet amount measuring device 1 is output to the inkjet coating device K and used for calibrating the droplet amount with respect to the ejection time Ts and the driving current / voltage of each inkjet nozzle Jn. ..

The reference droplet amount measuring unit 2 designates at least one of the plurality of inkjet nozzles Jn as the reference nozzle JI and measures the droplet amount VI of the reference droplet LI ejected from the reference nozzle JI. ..

Specifically, the reference droplet amount measurement unit 2 includes a discharge control unit, a flying object imaging unit 21, a reference droplet amount calculation unit, a reference droplet amount registration unit, and the like.

The ejection control unit designates at least one of the plurality of inkjet nozzles Jn as the reference nozzle JI, and ejects the reference droplet LI from the reference nozzle JI.
Specifically, after moving the relative moving unit M to a position (P1, P4) where the reference droplet LI ejected from the reference nozzle JI can be imaged by the flying object imaging unit 21, the ejection control unit issues a reference command. A value (time, current / voltage) is applied to eject the reference droplet LI from the reference nozzle JI.
More specifically, the discharge control unit is composed of a coating unit N and a part of the control unit C2.

The flying object imaging unit 21 images the flying reference droplet LI ejected from the inkjet nozzle designated as the reference nozzle JI, and outputs the image Ps including the reference droplet LI.

Specifically, the flying object imaging unit 21 includes an imaging camera (also referred to as a flight observation camera).

More specifically, the flying object image pickup unit 21 includes CMOS or CCD as an image pickup element and outputs the captured image Ps to the outside, and the droplet LI ejected from the reference nozzle JI is right beside the flight path. It is arranged so that it can be imaged from (for example, the Y direction).

The reference droplet amount calculation unit measures the droplet amount VI of the reference droplet LI based on the image Ps captured by the flying object imaging unit 21.

Specifically, the reference droplet amount calculation unit extracts the contour of the reference droplet LI included in the image Ps captured by the flying object imaging unit 21, and determines how many pixels the area surrounded by the contour is. The vertical projection area of the reference droplet LI is calculated by counting, and the liquid drop amount VI of the reference droplet LI is calculated based on the contour shape and the vertical projection area.

More specifically, the reference droplet amount calculation unit is composed of a part of the processing unit C1 of the inkjet coating device K, and the reference droplet LI included in the image Ps captured by the flying object imaging unit 21. Considers the contour as a rotating body having a cross-sectional shape, and performs a process of integrating the vertically projected area to calculate the volume (that is, the liquid drop model VI).

The reference droplet amount registration unit registers the droplet amount VI of the reference nozzle JI with respect to the reference command value (time, current / voltage). Specifically, the reference droplet amount registration unit registers the droplet amount VI of the reference droplet LI calculated by the reference droplet amount calculation unit described above. More specifically, the reference droplet amount registration unit is composed of a part of the processing unit C1 of the inkjet coating device K.

The measurement surface 3 lands the droplet Ln and the reference droplet LI ejected from the plurality of inkjet nozzles Jn.

FIG. 4 is a perspective view showing another main part of an example of a form embodying the present invention, and FIG. 4 shows a state in which the measurement surface 3 is viewed from diagonally above.

Specifically, the measurement surface 3 is mounted on the frame f of the inkjet coating device K so that the upper surface thereof is a horizontal plane (that is, an XY plane).

More specifically, the measurement surface 3 is made of a transparent resin film 30, and a lighting unit 31 is provided below the resin film 30. Further, the resin film 30 is supplied from a winding roll (not shown) and wound on a winding roll (not shown), that is, transported and supplied by a so-called roll-to-roll method, and is transported in the middle of the transport path. Rollers 32 to 35 are arranged. Therefore, in the resin film 30, after the area measurement of the reference droplet QIn and each droplet QMn landing on the measurement surface 3 is completed, the portion to which the droplet QM is attached is wound around the winding roll. At the same time, the portion to which the respective liquid drops QIn and QMn are not attached is supplied from the unwinding roll, and the measurement surface 3 is refreshed.

The illumination unit 31 irradiates the illumination light from the lower surface side of the resin film 30 constituting the measurement surface 3 upward. Specifically, the illumination unit 31 is provided with a light source that emits white light such as an LED or a fluorescent lamp or light having a wavelength having a high absorption rate in the droplet QMn to be measured (so-called transmission illumination). Can be exemplified.

FIG. 5 is a plan view showing an example of landing of a liquid drop in an example of a form embodying the present invention. FIG. 5 shows an arrangement image of the reference droplet QIn, each droplet QMn, and the like that are ejected from the reference nozzle JI and the plurality of inkjet nozzles Jn and land on the measurement surface 3. Further, in FIG. 5, the imaging region of the image P set on the measurement surface 3 is shown by a broken line, and the boundary of the sections having close wettability on the measurement surface 3 is shown by a two-dot chain line.

The image acquisition unit 4 acquires an image P including a reference liquid drop QIn and each liquid drop QMn landed on the measurement surface 3.

Specifically, the image acquisition unit 4 includes an image pickup camera 41.

The image pickup camera 41 captures a region including a reference droplet QIn and each droplet QMn ejected from a plurality of inkjet nozzles Jn and landed on the measurement surface 3, and is above the measurement surface 3. It is arranged so as to image the measurement surface 3 downward in the Z direction.

Specifically, the image pickup camera 41 includes CMOS or CCD as an image pickup element, and outputs the captured image P to the outside. In this case, the difference in the amount of light passing through the transparent resin film 30 and the light passing through the landed droplet Qn causes a difference in brightness between the background in the image P and the droplet Qn, so that the droplet Q is discriminated. it can.

The droplet amount measuring unit 5 measures the droplet amount VMn of each droplet QMn contained in the image P and performs processing related to the measurement.

Specifically, the droplet amount measuring unit 5 performs image processing, arithmetic processing, and the like according to a procedure registered in advance, measures the area SMn of each droplet QMn contained in the image P, and drops droplets from the area SMn. An arithmetic process for calculating the quantity VMn is performed.

More specifically, the droplet amount measuring unit 5 is composed of a part of the processing unit C1 of the inkjet coating device K, and the droplet area measuring unit 51, the conversion coefficient registration unit 52, the correction coefficient registration unit 53, and the like. It includes a conversion coefficient calculation unit 54, a correction coefficient calculation unit 55, a droplet amount calculation unit 56, and the like.

The droplet area measuring unit 51 measures the area SMN of each droplet QMn included in the image P.

Specifically, the droplet area measuring unit 51 extracts the contour of each droplet QMn included in the image P based on a predetermined image processing procedure, and the area surrounded by the contour is the number of pixels. The area SMn of each liquid drop QMn is measured by counting whether or not there is a minute.

The conversion coefficient registration unit 52 registers the area volume conversion coefficient α for converting the droplet amount (that is, volume) VMn from the area SMn of each droplet QMn measured by the droplet area measurement unit 51. is there. The area-volume conversion coefficient α is calculated by the conversion coefficient calculation unit 54.

The correction coefficient registration unit 53 determines the area SMn of each droplet QMn measured by the droplet area measurement unit 51 for each location or section of the measurement surface 3 in view of the fact that the wettability differs for each location of the measurement surface 3. The wettability correction coefficient βxy for correction is registered. The wettability correction coefficient βxy is calculated by the correction coefficient calculation unit 55. The wettability correction coefficient βxy is associated with position information (coordinates, addresses, etc.) indicating a location or section on the measurement surface 3, and is represented by adding the symbol xy.

The conversion coefficient calculation unit 54 calculates the area / volume conversion coefficient α.

Specifically, the conversion coefficient calculation unit 54 calculates the area volume conversion coefficient α based on the relationship between the area SI of the reference droplet QI landed on the measurement surface 3 and the droplet amount VI.
More specifically, the conversion coefficient calculation unit 54 sets a representative location on the measurement surface 3 in advance, and the droplet area measurement unit 51 determines the area SI of the reference droplet QI landed at this representative location. From the droplet amount VI of the reference droplet LI measured by the reference droplet amount measuring unit 2 while measuring, the following equation α = VI / SI
The area-volume conversion coefficient α is calculated based on.

The correction coefficient calculation unit 55 calculates the wettability correction coefficient βxy.

Specifically, the correction coefficient calculation unit 55 sets the area SIxy of each reference droplet QIxy of the same droplet amount VI landed on a plurality of locations on the measurement surface 3 and the area SI of the reference droplet QI of the representative location. From the ratio of, the following equation βxy ＝ SIxy / SI
The wettability correction coefficient βxy is calculated based on. The symbol xy added to the reference liquid drop model QIxy and the area SIxy is position information (coordinates, addresses, etc.) indicating a location or section on the measurement surface 3.

The droplet amount calculation unit 56 calculates the droplet amount VMn of each droplet QMn based on the measured area SMn of each droplet QMn, the area volume conversion coefficient α, and the wettability correction coefficient βxy. Specifically, the droplet amount calculation unit 56 includes the area SMn of each droplet QMn measured by the droplet area measurement unit 51, the area volume conversion coefficient α registered in the conversion coefficient registration unit 52, and each liquid. The position information of the drop QMn on the measurement surface 3, the wettability correction coefficient βxy registered in the correction coefficient registration unit 53, and the following equation VMn = α × βxy × SMn
The liquid drop amount VMn is calculated based on.

In addition to the "coating mode", the inkjet coating device K includes a "reference droplet amount measurement mode", an "area volume conversion coefficient calculation mode", a "wetting property correction coefficient calculation mode", and a "droplet amount measurement mode". There is. The inkjet coating device K switches these operation modes and executes the operation, and the droplet amount inspection device 1 measures the droplet amount VMn of the droplet Ln, the area volume conversion coefficient α required for measuring the droplet amount VMn, and the like. Wetness correction coefficient βxy and the like can be calculated. Specifically, the inkjet coating device K performs a predetermined process or the like while controlling each unit by the execution program of the processing unit C1 or the control unit C2 in which the procedure described below is registered.

About "reference droplet amount measurement mode" This operation mode is for measuring the droplet amount VI of the reference droplet LI ejected from the reference nozzle JI.

FIG. 6 is a flow chart in an example of a form embodying the present invention. FIG. 6 schematically illustrates the operation flow / procedure of the “reference droplet amount measurement mode” in the droplet amount measuring device 1 and the inkjet coating device K.

It is defined in advance which of the plurality of inkjet nozzles Jn of the coating unit N is used as the reference nozzle JI.

Then, as shown in FIG. 1, the relative moving unit M is moved to a position (P1, P4) where the flying reference droplet LI ejected from the reference nozzle JI can be imaged by the flying object imaging unit 21 (step s11). ).

The reference droplet LI is ejected from the reference nozzle JI at the reference command value (time, current / voltage), and the reference droplet LI is imaged by the flying object imaging unit 21 (step s12). Specifically, the ejection control unit of the reference droplet amount measuring unit 2 applies a predetermined driving current / voltage to the reference nozzle JI for a predetermined time Ts to eject the reference droplet LI.

The volume (that is, the amount of droplets) VI of the reference droplet LI is measured based on the image Ps in which the reference droplet LI in flight is captured by the flying object imaging unit 21 (step s13). Specifically, the reference droplet amount calculation unit of the reference droplet amount measurement unit 2 extracts the contour of the reference droplet LI in flight and counts the number of pixels in the area surrounded by the contour. The vertical projected area of the reference droplet LI is calculated, the reference droplet LI is regarded as a rotating body having the contour as a cross-sectional shape, and the vertical projected area is integrated to calculate the volume VI (step s14).

The droplet amount VI of the reference nozzle JI with respect to the reference command value (time, current / voltage) is registered in the reference droplet amount registration unit of the reference droplet amount measurement unit 2 (step s15).

About "Area-volume conversion coefficient calculation mode" This operation mode is for calculating the area-volume conversion coefficient α.

FIG. 7 is a flow chart in an example of a form embodying the present invention. FIG. 7 schematically illustrates the operation flow / procedure of the “area / volume conversion coefficient calculation mode” in the droplet amount measuring device 1 and the inkjet coating device K.

The droplet amount VI of the droplet LI ejected from the reference nozzle JI is measured in advance in the above-mentioned "reference droplet amount measurement mode" (steps s11 to s15).

Then, as shown in FIG. 1, the flying object imaging unit 21 and the imaging camera 41 are moved to the retracted position (P4, etc.), and the reference nozzle JI and the measurement surface 3 are relatively moved while facing each other (near the position P1). The reference liquid drop LI is ejected to the representative point on the measurement surface 3 (step s21). Specifically, a predetermined drive current / voltage is applied to the reference nozzle JI for a predetermined time for a predetermined time to eject the reference droplet LI.

Then, as shown in FIG. 3, the coating unit N is moved to the retracted position (P2, etc.), the relative moving unit M is moved to the position (P5) where the image pickup camera 41 faces the measurement surface 3, and the measurement surface 3 is moved. The image P including the landed reference droplet QI is imaged by the image pickup camera 41 of the image acquisition unit 4 (step s22).

Based on the image P, the area SI is measured for the reference droplet QI (step s23). Specifically, the image P is image-processed, the contour of the reference droplet QI is extracted, and the area SI of the reference droplet QI is calculated by counting the number of pixels in the area surrounded by the contour.

The area-volume conversion coefficient α for calculating the droplet amount VI is calculated from the area SI of the reference droplet QI (step s24).

The calculated area-volume conversion coefficient α is registered in the conversion coefficient registration unit 52 (step s25).

At least one representative point may be set, but a plurality of representative points may be set. For example, when a plurality of points are set as representative points, the area volume conversion coefficient α may be calculated from the total area / total droplet amount of the plurality of droplets.

About "wetting correction coefficient calculation mode" This operation mode is for calculating the wetting correction coefficient βxy.

FIG. 8 is a flow chart in an example of a form embodying the present invention. FIG. 8 schematically illustrates the operation flow / procedure of the “wetting property correction coefficient calculation mode” in the droplet amount measuring device 1 and the inkjet coating device K.

The droplet amount VI of the droplet LI ejected from the reference nozzle JI is measured in advance in the above-mentioned "reference droplet amount measurement mode" (steps s11 to s15).

As shown in FIG. 1, the flying object imaging unit 21 and the imaging camera 41 are moved to the retracted position (P4, etc.), and the reference nozzle JI and the measurement surface 3 are relatively moved while facing each other (near the position P1). While moving the reference nozzle JI and the measurement surface 3 relative to each other, the reference droplet LI is ejected to a plurality of locations including the representative points on the measurement surface 3 (step s31). Specifically, a predetermined drive current / voltage is applied to the reference nozzle JI for a predetermined time for a predetermined time to eject the reference droplet LI.

Then, as shown in FIG. 3, the coating unit N is moved to the retracted position (P2, etc.), and the relative moving unit M is moved to the position (P5) where the imaging camera 41 faces the measurement surface 3, and is on the measurement surface 3. The image P including the reference droplet QIxy landed at the plurality of locations of the above is captured by the observation camera 41 (step s32).

Based on the image P, the area SIxy is measured for each of the plurality of reference droplets QIxy (step s33). Specifically, the image P is image-processed, the contours of each of the reference droplet QIxys are extracted, and the area SIxy of each reference droplet QIxy is calculated by counting the number of pixels in the area surrounded by the contours. calculate.

The wettability correction coefficient βxy is calculated from the ratio of the area SIxy of each reference droplet QIxy of the same droplet amount VI landed at a plurality of locations on the measurement surface 3 to the area SI of the reference droplet QI of the representative location. (Step s34).

The calculated wettability correction coefficient βxy is associated with the position information of the reference droplet QIxy and registered in the correction coefficient registration unit 53 (step s35).

About "droplet amount measurement mode" This operation mode is a mode for measuring the droplet amount VMn of the droplet Ln ejected from the inkjet nozzle Jn to be measured. Specifically, the area SMn of each droplet QMn is measured, and the droplet is based on the relationship between the position information of each droplet QMn on the measurement surface 3 and the area volume conversion coefficient α and the wettability correction coefficient βxy. It is for calculating the quantity VMn.

FIG. 9 is a flow chart in an example of a form embodying the present invention. FIG. 9 schematically illustrates the operation flow / procedure of the “droplet amount measurement mode” in the droplet amount measuring device 1 and the inkjet coating device K.

As shown in FIG. 1, the flying object imaging unit 21 and the imaging camera 41 are moved to a retracted position (P4, etc.), and the relative moving unit M is moved to a position (P1) where the coating unit N faces the measurement surface 3 (P1). Step s41).

A reference command value (time, current / voltage) is output to a plurality of inkjet nozzles Jn to be measured for the droplet, and the droplet Ln is ejected toward the measurement surface 3 (step s42). Specifically, a predetermined drive current / voltage is applied to each nozzle Jn for a predetermined time for a predetermined time, and each droplet Ln is discharged.

Then, as shown in FIG. 3, the coating unit N is moved to the retracted position (P2, etc.), the relative moving unit M is moved to the position (P5) where the image pickup camera 41 faces the measurement surface 3, and the measurement surface 3 is moved. The image P including each landed droplet QMn is imaged by the image pickup camera 41 (step s43).

Based on the image P, the area SMN of each droplet QMn from the measurement target nozzle is measured (step s44).

Area SMn measured by the droplet area measurement unit 51, area volume conversion coefficient α registered in the conversion coefficient registration unit 52, position information of the reference droplet QIxy, and wettability registered in the correction coefficient registration unit 53. Correction coefficient βxy and the following equation VMn = α × βxy × SMn
Based on the above, each liquid drop amount VMn is calculated (step s45).

Due to such a configuration, the droplet amount measuring device 1 measures the area SMn of each droplet QMn included in the image P at once by the droplet amount measuring unit 5, and accurately measures the droplet amount VMn. Can be calculated, so that the liquid drop amount VMn of each liquid drop Ln ejected from the plurality of inkjet nozzles Jn can be measured quickly and accurately.

Therefore, based on the result obtained by the inspection unit 5 of the droplet amount measuring device 1, is the inkjet coating device K capable of ejecting the droplet amount VMn in a predetermined range for each of the plurality of inkjet nozzles Jn? It is possible to quickly and surely perform various inspections such as whether or not there is clogging and whether or not there is any problem even if it is used in the "application mode".

The above-mentioned "area volume conversion coefficient calculation mode", "wetness correction coefficient calculation mode", and "droplet amount measurement mode" may be executed separately (that is, in series), but the reference liquid The ejection of the droplet LI and each droplet Ln and the imaging of the image P including the landed reference droplet QI and each droplet QMn may be executed in parallel. Specifically, the above-mentioned droplet ejection steps s21, s31, and s42 are performed as a series of operations, the image P is imaged (steps s22, s32, s43) at one time, and the area volume conversion coefficient α and the wettability correction are performed. After calculating and registering the coefficient β (steps s24 and s34) (steps s25 and s35), the area SMn of each droplet QMn is measured (step s44) and the droplet amount VMn is calculated (step s45). By doing so, it is possible to reduce the time spent for discharging the reference liquid drop model LI and each liquid drop model Ln and for capturing the image P, which is preferable.

[Modification example]
In the above description, a predetermined driving current / voltage is applied to the reference nozzle JI and a plurality of inkjet nozzles Jn to be measured for a predetermined time Ts, and the reference droplet LI and each droplet are applied once from one nozzle. The configuration in which Ln is discharged and the reference droplet QI and each droplet QM are landed on the measurement surface 3 is shown.

However, in embodying the present invention, the configuration is not limited to the configuration in which droplets are ejected once from one nozzle, and the reference droplet LI and each droplet Ln ejected a plurality of times from one nozzle are ejected for each nozzle. One droplet QIn, QMn may be formed by landing on the same place on the measurement surface 3.

Alternatively, the landing positions of the liquid drops LI and Ln discharged multiple times from one nozzle are shifted, and the liquid drop amount VI and VMn are calculated from the total value (or average value) of the areas of each of the plurality of droplets QIn and QMn. It may be configured.

In each of the inkjet nozzles Jn to be measured, droplets LI and Ln are ejected multiple times from one nozzle and landed at the same place or the landing position is shifted, so that the amount of droplets VI and VMn varies. Is averaged, so that the droplet amounts VI and VMn of the droplets LI and Ln discharged from each nozzle can be measured more accurately. Regarding whether the droplets ejected from one nozzle are overlapped at the same position, the landing position is shifted, or the droplets are not overlapped / not overlapped, the viscosity and drying speed of each droplet QIn, QMn, and the required time for each operation are determined. , It may be determined based on the required measurement accuracy and the like.

[Modification example]
In embodying the present invention, the reference droplet QI and the droplet QMn to be measured for the amount of the droplet amount are landed on the measurement surface 3 at the positions shown by the solid lines in FIG. By acquiring the image P including the above, the liquid drop LI, Ln droplet amount VI, VMn discharged from each nozzle can be measured quickly and accurately.

However, when the drying rate of each droplet QIn and QMn is high and accompanied by volume shrinkage, the droplets at the corners and edges and the droplets surrounded by other droplets have an atmosphere around the droplets. Moisture (due to evaporated moisture or solvent) may vary. In such a case, the degree of volume contraction differs between the droplets at the corners and edges and the droplets surrounded by other droplets, and when the image P is imaged, the area ratio becomes different. It may be different, and an error may occur in the calculated droplet amount V.

In order to reduce such an influence, dummy droplets that slow down the drying rate of the droplets QIn and QMn are placed around the droplets QIn and QMn to be measured on the measurement surface 3. It is preferable that Qd is applied.

The dummy droplet Qd is obtained by ejecting the same coating liquid as each droplet QIn and QMn from an inkjet nozzle Jn to be measured or an inkjet nozzle not to be measured. Specifically, the dummy liquid drop Qd is a place where each liquid drop QIn, QMn has not landed so that each liquid drop QIn, QMn is surrounded by other liquid drops (for example, in FIG. 5). And land at the position indicated by the broken line circle). It should be noted that how much the dummy droplet Qd is landed, how many layers each droplet QIn and QMn are surrounded by the dummy droplet Qd, how much the size and density of the dummy droplet Qd should be, etc. are determined. It may be determined based on the viscosity and drying rate of the liquid drops QIn and QMn, the time required for each operation, the required measurement accuracy, and the like.

By doing so, the moistness of the atmosphere around the reference droplet QIn and each droplet QMn can be made uniform, the variation in the drying rate of the reference droplet QIn and each droplet QIn, QMn can be reduced, and the amount of droplets can be reduced. VI and VMn can be measured more accurately. That is, the liquid drop amount VMn of the droplet Ln ejected from the plurality of inkjet nozzles Jn to be measured can be measured quickly and accurately.

[Modification example: Relative moving part M]
In the above description, as a specific configuration of the relative moving unit M, the discharge unit N is attached to the first gantry unit M3, and the imaging cameras 21 and 41 are attached to the second gantry unit M6. With such a configuration, the discharge unit N and the imaging cameras 21 and 41 can move / stop in the Y direction.

However, in embodying the present invention, the relative moving portion M is not limited to such a configuration and may have a configuration as described below. For example, the first gantry portion M3 is provided with an actuator capable of moving / stopping in the X direction, and the discharge unit N is attached to the movable portion of the actuator. Similarly, the second gantry unit M6 is provided with an actuator that can move / stop in the X direction, and the image pickup cameras 21 and 41 are attached to the movable portion of the actuator.

[Modification example: Measurement surface 3 / Image acquisition unit 4]
In the above description, as a specific example of the measurement surface 3, a configuration (transmitted illumination) in which a transparent resin film 30 is formed and a lighting unit 31 is provided below the resin film 30 is shown. Further, the image acquisition unit 4 is provided with an image pickup camera 41 arranged so as to image the measurement surface 3 downward in the Z direction.

However, instead of providing such transmitted illumination on the measurement surface 3, an illumination unit that irradiates the image pickup camera 41 side of the image acquisition unit 4 with light from directly above or diagonally above the measurement surface 3 (coaxial oblique illumination, It may be configured to include oblique lighting, etc.). In this case, the difference in brightness between the background in the image P and the droplet Qn is caused by the difference in the amount of light reflected or scattered by the measurement surface 3 and the light reflected or scattered by the droplet Qn, so that the droplet Q is discriminated. it can.

[Modification example: Reference droplet amount measuring unit 2 / Droplet amount measuring unit 5]
In the above description, as a specific example of the reference droplet amount measuring unit 2, the ejection control unit is composed of a coating unit N and a part of the control unit C2, and the reference droplet amount calculation unit 2 is the inkjet coating device K. An example of being composed of a part of the processing unit C1 is shown. Further, an example is shown in which the droplet amount measuring unit 5 is composed of a part of the processing unit C1 of the inkjet coating device K.

However, a part or all of the reference droplet amount measuring unit 2 and the droplet amount measuring unit 5
It may be configured to include a computer CN or an image processing device GP (that is, hardware) having an image processing function separately, and an execution program (software) thereof.

In the above description, as the first embodiment of the present invention, the droplet amount measuring device 1 and the inkjet coating device K provided with the liquid drop model measuring device 1 have been described in detail. In this embodiment, the reference nozzle JI for ejecting the reference droplet LI is one in which at least one of the plurality of inkjet nozzles Jn used in the "coating mode" provided in the coating unit N is designated as the reference nozzle JI. is there. Then, the reference droplet amount measuring unit 2 measured the droplet amount VI by flying observation of the droplets ejected from the nozzle designated as the reference nozzle JI.

However, the present invention can be embodied not only in the first form described above but also in the second form as described below.

[Second form]
10 and 11 are schematic views showing an overall configuration of an example of a second embodiment embodying the present invention. 10 and 11 show a schematic view of the liquid drop model measuring device 1b according to the second aspect of the present invention and the inkjet coating device Kb provided with the device 1b.

The droplet amount measuring device 1b measures the droplet amount VMn of each droplet Ln ejected from the plurality of inkjet nozzles Jn, and has many configurations common to the above-mentioned droplet amount measuring device 1. , The explanation will focus on the different configurations. Further, since the inkjet coating device Kb also has many configurations in common with the inkjet coating device K, different configurations will be mainly described. It should be noted that detailed description of configurations common to each other (also referred to as similar parts) will be omitted.

The inkjet coating device Kb is provided with a dedicated inkjet nozzle JF in addition to the plurality of inkjet nozzles Jn used in the "coating mode" provided in the coating unit N, and is configured to be used as a reference nozzle JI. There is. The dedicated inkjet nozzle JF is connected to the discharge tank 13 via a liquid supply route that is branched and connected to the discharge unit N.

The droplet amount measuring device 1b includes a reference droplet amount measuring unit 2b (instead of the above-mentioned reference droplet amount measuring unit 2), and the reference droplet amount measuring unit 2b is a flying object imaging unit 22 (described above). (Alternative to the flying object imaging unit 21).

The flying object imaging unit 22 is for capturing the flying reference droplet LI ejected from the inkjet nozzle JF (that is, the reference nozzle JI) and grasping the cross-sectional shape of the reference droplet LI. It is equipped with (also called a flight observation camera). Specifically, the flying object image pickup unit 22 is provided with CMOS or CCD as an image pickup element and outputs the captured image Ps to the outside, and the droplet LI ejected from the reference nozzle JI is right beside the flight path ( For example, it is arranged so that it can be imaged from the Y direction). More specifically, the flying object imaging unit 22 is attached to the second gantry M6 or the device frame, and is arranged so that the droplet LI ejected from the inkjet nozzle JF can be imaged.

About "reference droplet amount measurement mode" This operation mode is for measuring the droplet amount VI of the droplet LI ejected from the inkjet nozzle JF (that is, the reference nozzle JI).

First, in order for the flying object imaging unit 22 to image the flying reference droplet LI ejected from the reference nozzle JI, for example, as shown in FIG. 10, the reference nozzle JI and the measurement surface 3 face each other or at an arbitrary position. The relative moving unit M is moved to the position (P4 or the like) (step s11).

The other operation steps s12 to s15 are the same as those in the first mode described above.

About "Area volume conversion coefficient calculation mode" In this operation mode, as shown in FIG. 10, the flying object imaging unit 22 and the imaging camera 41 are moved to the retracted position (P4, etc.), and the reference nozzle JI and the measurement surface 3 are moved to each other. The reference liquid drop LI is ejected to the representative point on the measurement surface 3 while being relatively moved while being arranged facing each other (near the position P4) (step s21). Specifically, a predetermined drive current / voltage is applied to the reference nozzle JI for a predetermined time for a predetermined time to eject the reference droplet LI.

Then, as shown in FIG. 11, the coating unit N is moved to the retracted position (P2, etc.), the relative moving unit M is moved to the position (P5) where the image pickup camera 41 faces the measurement surface 3, and the measurement surface 3 is moved. The image P including the landed reference droplet QI is imaged by the image pickup camera 41 of the image acquisition unit 4 (step s22).

The other operation steps s23 to s25 are the same as those in the first mode described above.

About "wetting correction coefficient calculation mode" In this operation mode, as shown in FIG. 10, the flying object imaging unit 22 and the imaging camera 41 are moved to the retracted position (P4, etc.), and the reference nozzle JI and the measurement surface 3 are moved to each other. While moving relative to each other while arranging them facing each other (near position P4), while moving the reference nozzle JI and the measurement surface 3 relative to each other, the reference droplet LI is ejected to a plurality of locations including the representative point on the measurement surface 3 (step). s31). Specifically, a predetermined drive current / voltage is applied to the reference nozzle JI for a predetermined time for a predetermined time to eject the reference droplet LI.

Then, as shown in FIG. 11, the coating unit N is moved to the retracted position (P2, etc.), the relative moving unit M is moved to the position (P5) where the image pickup camera 41 faces the measurement surface 3, and the measurement surface 3 is moved. The image P including the landed reference droplet QIxy is captured by the observation camera 41 (step s32).

The other operation steps s33 to s35 are the same as those in the first mode described above.

About "droplet amount measurement mode" In this operation mode, as shown in FIG. 10, the flying object imaging unit 22 and the imaging camera 41 are moved to a retracted position (P4, etc.), and the coating unit N faces the measurement surface 3. The relative moving unit M is moved to the position (P1) (step s41).

Then, after executing step s42, as shown in FIG. 11, the coating unit N is moved to the retracted position (P2, etc.), and the relative moving unit M is moved to the position (P5) where the imaging camera 41 faces the measurement surface 3. An image P including each liquid drop QMn that has been moved and landed on the measurement surface 3 is imaged by the image pickup camera 41 (step s43).

The other operation steps s44 to s45 are the same as those in the first mode described above.

Due to such a configuration, even in the droplet amount measuring device 1b, the area SMn of each droplet QMn included in the image P is measured at once by the droplet amount measuring unit 5 to obtain an accurate droplet amount. Since the vmn can be calculated, the liquid drop amount vmn of each droplet Ln ejected from the plurality of inkjet nozzles Jn can be measured quickly and accurately.

Therefore, based on the result obtained by the inspection unit 5 of the droplet amount measuring device 1b, is the inkjet coating device Kb capable of ejecting the droplet amount VMn in a predetermined range for each of the plurality of inkjet nozzles Jn? It is possible to quickly and surely perform various inspections such as whether or not there is clogging and whether or not there is any problem even if it is used in the "application mode".

In the above description, the configuration in which the flying object imaging unit 22 of the reference droplet amount measuring unit 2b is attached to the second gantry M6 is illustrated. With such a configuration, the operation of ejecting the reference droplet LI onto the measurement surface 3 and the operation of capturing the image Ps including the reference droplet LI in flight by the flying object imaging unit 22 are performed at the same time. This is preferable from the viewpoint of time saving. However, the flying object imaging unit 22 is not limited to such a configuration as long as it is not necessary to shorten the time, and the flying object imaging unit 22 may be attached to the device frame f via a mounting bracket or the like. For example, the second gantry M6 may be moved to another position P6 or the like for imaging.

Also in the second embodiment, the modified example shown in the first embodiment (a configuration in which droplets QI and QMn are ejected multiple times from one of the inkjet nozzles Jn to be measured and landed at the same place, and measurement A configuration in which a dummy droplet Qd is landed on the surface 3, an illumination method, etc.) can be similarly applied.

In this embodiment, the discharge unit N and the reference nozzle JI have separate configurations and are attached to the first gantry section M1 and the second gantry M6, which operate independently of each other. Therefore, the droplet amount of the reference nozzle JI can be measured by executing the "reference droplet amount measurement mode" while executing the "coating mode" using the ejection unit N. That is, it is preferable because the preparation necessary for measuring the liquid drop model can be performed without significantly impairing the operating time of the inkjet coating device Kb.

In the above description, the inkjet coating devices K and Kb are provided with the droplet amount measuring devices 1, 1b, the measuring surface 3, and the like, and the area of the reference droplet QI and the droplet QMn landed on the measuring surface 3 is used. Based on this, an example is shown in which the droplet amount (volume) of the droplet Ln discharged from each nozzle Jn is measured by the droplet amount measuring devices 1 and 1b.

However, instead of such a measurement surface 3, the measurement substrate Ws as described below is used to measure the liquid drop amount (volume) VMn of the liquid droplet Ln discharged from each nozzle Jn of the inkjet coating device. It may be in the form.

[Third form]
FIG. 12 is a schematic view showing an overall configuration of an example of a third embodiment embodying the present invention. FIG. 12 shows a schematic view of the liquid drop model measuring system 1s according to the third embodiment of the present invention.

The droplet amount measuring system 1s measures the droplet amount VMn of each droplet Ln ejected from each inkjet nozzle Jn provided in the ejection unit N of the inkjet coating device Kc. Specifically, the droplet amount measurement system 1s includes a measurement substrate preparation unit G, a reference droplet amount measurement unit 2b, an image acquisition unit 4, a droplet measurement unit 5, a host computer HC, a substrate transfer unit RH, and the like. It is composed of.

The droplet amount measurement system 1s includes a "reference droplet amount measurement mode", an "area volume conversion coefficient calculation mode", a "wetting property correction coefficient calculation mode", and a "droplet amount measurement mode".

The droplet amount measurement system 1s switches and executes these operation modes to measure the reference droplet LI and the droplet amounts VI and VMn of each droplet Ln, and to convert the area and volume required for measuring the droplet amount VMn. The coefficient α, the wettability correction coefficient βxy, and the like can be calculated.

The inkjet coating device Kc ejects liquid drops Ln onto the substrate W and the measurement substrate Ws, and performs a predetermined coating operation on the substrate W and the measurement substrate Ws. The inkjet coating device Kc omits the droplet amount measuring device 1b and the reference nozzle JI from the above-mentioned second-form inkjet coating device Kb, and has the same configuration other than that. Therefore, the inkjet coating device Kc can execute a "coating mode" in which a predetermined coating operation is performed on the substrate W or the measurement substrate Ws.

The measurement board preparation unit G prepares the measurement board Ws on which the reference droplet LI is landed at a plurality of locations. Specifically, the measurement board preparation unit G includes a reference nozzle JI, a substrate holding unit GH, a relative moving unit GM, a processing unit GC1, a control unit GC2, and the like.

The reference nozzle JI ejects the reference droplet LI, and has the same configuration as the above-mentioned inkjet nozzle JF.

The substrate holding portion GH holds the measuring substrate W in a predetermined posture.

The relative moving unit GM moves the reference nozzle JI and the measurement substrate W relative to each other at a predetermined speed or makes them stand still at a predetermined position. Specifically, the relative moving unit GM includes a rail unit GM1, a slider unit GM2, and a gantry unit GM3.

The processing unit GC1 performs image processing, arithmetic processing, and the like according to a procedure registered in advance.

Specifically, the processing unit GC1 has the functions as described below.
-Image processing is performed on the acquired images P and Ps, and the outline of the detection target (droplet) is extracted.
-Count how many pixels the area surrounded by the contour extracted by the binarization process, the sub-pixel process, etc. is.
-The area of the area surrounded by the extracted contour is calculated from the area per pixel of the acquired images P and Ps.
-As a result obtained by image processing or calculation processing, predetermined calculation processing is performed based on pre-registered coefficients, mathematical formulas, and the like.

More specifically, the processing unit GC1 is composed of a computer CN having an image processing function, an image processing device GP (that is, hardware), and an execution program (software) thereof.

The control unit GC2 controls the substrate holding unit GH, the reference nozzle JI, the relative moving unit GM, the processing unit GC1, the droplet amount measuring device 2b, and the equipment of each unit, and refers to the reference droplets toward a plurality of locations of the measuring substrate Ws. LIn is discharged and the reference liquid drop QIn is landed. It should be noted that the position on the measurement substrate Ws where the reference liquid drop QIn is landed is set in advance.

Specifically, the control unit GC2 has the functions as described below.
-A command (signal output) is given to the substrate holding unit GH to hold / release the suction.
-The reference nozzle JI is instructed to eject the droplet LI.
-A movement / stationary command is given to the slider unit GM2 of the relative movement unit GM.
-Exchange data and signals with the processing unit GC1.
-The image acquisition trigger is output to the image acquisition unit 4.
-A trigger for starting measurement is output to the droplet amount measuring unit 5.

More specifically, the control unit GC2 is composed of a programmable logic controller, a computer CN, etc. (that is, hardware) and its execution program (that is, software), and signals and data output from the devices of each unit. Is input, predetermined arithmetic processing and the like are performed, and signals and data can be output to the devices of each part based on the processing result.

The reference droplet amount measuring unit 2b measures the droplet amount VIN of the reference droplet LI ejected from the reference nozzle JI. Specifically, the reference droplet amount measuring unit 2b has substantially the same configuration as that illustrated as the second embodiment described above, and is the ejection control unit, the flying object imaging unit 22, and the reference droplet amount calculation unit. , A reference droplet amount registration unit and the like are provided. The imaging camera provided in the flying object imaging unit 22 of the reference droplet amount measuring unit 2b is attached to the gantry unit GM3 of the measuring substrate preparation unit G.

The image acquisition unit 4 acquires an image P including a reference liquid drop QIn and each liquid drop QMn landed on the measurement substrate Ws. Specifically, the image acquisition unit 4 has substantially the same configuration as that illustrated as the second embodiment described above. The image acquisition unit 4 may be provided with an illumination unit (coaxial oblique illumination, oblique illumination, etc.) that irradiates light from directly above or diagonally above the measurement substrate Ws on the image pickup camera 41 side. .. Alternatively, the substrate holding portion GH may be provided with a lighting device (that is, transmitted illumination).

The droplet measurement unit 5 measures the reference droplet QIn included in the image P and the droplet amounts Vin and vmn of each droplet QMn, and performs processing related to the measurement. Specifically, the droplet measuring unit 5 has substantially the same configuration as that illustrated as the second embodiment described above.

The reference droplet amount measurement unit 2b, the image acquisition unit 4, and the processing unit of the droplet measurement unit 5 are composed of a part of the computer CN of the measurement substrate preparation unit G.

The substrate transfer unit RH conveys the measurement substrate Ws. Specifically, the substrate transfer unit RH transfers (also referred to as transfer or transfer) the measurement substrate Ws to the measurement substrate preparation unit G or the inkjet coating device Kc. More specifically, the substrate transport unit RH handles the measurement substrate Ws with a substrate transfer robot RH or a conveyor that can access the inside and outside of the measurement substrate preparation unit G and the inkjet coating device Kc.

The host computer HC determines at which position on the measurement substrate Ws the droplet Ln is ejected to land the droplet Qn, the droplet amount VMn of each inkjet nozzle Jn measured by the droplet amount measuring device 1s, and the like. Position information (coordinates, addresses, etc.) and numerical data are output to the inkjet coating device Kc.

About "reference droplet amount measurement mode" This operation mode is for measuring the droplet amount VI of the droplet LI ejected from the reference nozzle JI.

First, in order for the flying object imaging unit 22 to image the flying reference droplet LI ejected from the reference nozzle JI, for example, as shown in FIG. 12, the position where the reference nozzle JI and the measurement substrate Ws face each other or The relative moving unit GM is moved to an arbitrary position (step s11).

The other operation steps s12 to s15 are the same as those in the first and second modes described above.

About "Area volume conversion coefficient calculation mode" In this operation mode, as shown in FIG. 12, the relative moving unit GM is moved while the reference nozzle JI and the measuring board Ws are arranged to face each other on the measurement board preparation unit G side. The reference droplet LI is ejected to a representative point on the measurement substrate Ws (step s21). Specifically, a predetermined drive current / voltage is applied to the reference nozzle JI for a predetermined time for a predetermined time to eject the reference droplet LI.

Then, the relative moving unit GM is moved, and the image P including the reference droplet QI that has landed on the measurement substrate Ws is imaged by the image pickup camera 41 of the image acquisition unit 4 (step s22).

The other operation steps s23 to s25 are the same as those in the first and second modes described above.

About "wetting correction coefficient calculation mode" In this operation mode, the reference nozzle JI and the measurement board Ws are relatively moved while facing each other on the measurement board preparation unit G side, and a representative point on the measurement board Ws. The reference droplet LI is ejected to a plurality of locations including the above (step s31). Specifically, a predetermined drive current / voltage is applied to the reference nozzle JI for a predetermined time for a predetermined time to eject the reference droplet LI.

Then, the imaging camera 41 moves the relative moving unit GM to a position facing the measurement substrate Ws, and the observation camera 41 captures an image P including the reference droplet QIxy that has landed on the measurement substrate Ws (step s32). ).

The other operation steps s33 to s35 are the same as those in the first and second modes described above.

About "droplet amount measurement mode" In this operation mode, as shown in FIG. 12, the measurement substrate Ws is transferred to the Kc side of the inkjet coating apparatus in advance, and the coating unit N and the measurement substrate Ws are arranged to face each other. The relative moving unit M is moved while being moved (step s41).

A reference command value (time, current / voltage) is output to a plurality of inkjet nozzles Jn to be measured for droplets, and the droplet Ln is ejected toward a predetermined position on a preset measurement substrate Ws. (Step s42). Specifically, a predetermined drive current / voltage is applied to each nozzle Jn for a predetermined time for a predetermined time, and each droplet Ln is discharged.

Then, the measurement board Ws is transferred to the measurement board preparation unit G side, and the image pickup camera 41 includes each droplet QMn that has landed on the measurement board Ws while moving relative to the measurement board Ws. The image P is captured by the imaging camera 41 (step s43).

The other operation steps s44 to s45 are the same as those in the eleventh and second modes described above.

In the droplet amount measurement system 1s, the reference droplet LI and each liquid are used as the execution procedure of the above-mentioned "area volume conversion coefficient calculation mode", "wetness correction coefficient calculation mode", and "droplet amount measurement mode". It is preferable that the ejection of the droplet Ln and the imaging of the image P including the landed reference droplet QI and each droplet QMn are performed in parallel. Specifically, the above-mentioned droplet ejection steps s21, s31, and s42 are performed as a series of operations, the image P is imaged (steps s22, s32, s43) at one time, and the area volume conversion coefficient α and the wettability correction are performed. After calculating and registering the coefficient β (steps s24 and s34) (steps s25 and s35), the area SMn of each droplet QMn is measured (step s44) and the droplet amount VMn is calculated (step s45). By doing so, it is possible to reduce the time spent for replacing the measurement substrate Ws, ejecting the reference liquid drop model LI and each liquid drop model Ln, capturing the image P, and the like.

In the above description, as the droplet amount measurement system 1s according to the present invention, the reference droplet amount measurement unit 2b, the image acquisition unit 4, and the droplet measurement unit 5 are on the G side of the measurement substrate preparation unit as illustrated in FIG. The configuration is shown in preparation for.

In the case of such a configuration, after the measurement substrate Ws is transferred to the inkjet coating device Kc, the measurement substrate Ws on which the liquid drop QMn is landed is transferred to the measurement substrate preparation unit G side again to liquid. The drop measurement unit 5 accurately measures the amount of droplets.

Alternatively, the measurement substrate Ws on which the reference droplet QI has not yet landed is ejected from each inkjet nozzle Jn using the inkjet coating device Kc to land the droplet QMn, and the measurement substrate Ws is used later. The reference droplet QI may be landed using the measurement substrate preparation unit G to acquire the image P, and the droplet amount VMn may be measured.

It should be noted that which of the measurement substrate preparation unit G and the inkjet coating device Kc should land the droplets on the measurement substrate Ws first depends on the viscosity and drying speed of each droplet QIn and QMn, and each operation. It may be determined based on the time, the required measurement accuracy, and the like.

Further, in embodying the present invention, the image acquisition unit 4 and the droplet measurement unit 5 may have a configuration provided on the Kc side of the inkjet coating device as illustrated in FIG.
FIG. 13 is a schematic view showing the overall configuration of another example of the third embodiment embodying the present invention. FIG. 13 shows a schematic view of another example of the liquid drop model measuring system 1s according to the third embodiment of the present invention.

Alternatively, a dedicated device for measuring the amount of droplets provided with the image acquisition unit 4 and the droplet measurement unit 5 is prepared, and the liquid of the droplet Ln discharged from each inkjet nozzle Jn of the inkjet coating device Kc by the device. It may be configured to measure the liquid drop model VMn. In this case, the measurement board Ws is handed over by the board transport unit RH, and data or the like is handed over via the host computer HC.

Further, in the above description, the configuration in which the reference droplet amount measuring unit 2b and the Nkujet coating device Kc are provided with the droplet measuring unit 5 is illustrated, but the droplet measuring unit 5 is provided in the host computer HC. Is also good.

Also in the third form, the modified examples shown in the first and second forms (a configuration in which droplets QI and QMn are ejected a plurality of times from one of the inkjet nozzles Jn to be measured and landed at the same place. Alternatively, the measurement surface 3 / the configuration in which the dummy droplet Qd is landed on the measurement substrate Ws) can be similarly applied.

1,1b Droplet amount measuring device 2,2b Reference droplet amount measuring unit 3 Measuring surface 4 Image acquisition unit 5 Droplet amount measuring unit 13 Discharge liquid supply tank 21 Flying object imaging unit (flying observation camera)
25 Lighting unit 30 Resin film 31 Lighting unit 32 to 35 Conveying roller 41 Imaging camera (for landing droplets)
51 Liquid drop area measurement unit 52 Conversion coefficient registration unit 53 Correction coefficient registration unit 54 Conversion coefficient calculation unit 55 Correction coefficient calculation unit 56 Droplet amount calculation unit K, Kb, Kc Inkjet coating device H Substrate holding unit N Discharge unit (coating nozzle) )
J Inkjet nozzle (measurement target)
JI reference nozzle M Relative movement part M1 Rail part M2 Slider part M3 1st gantry part M4 Rail part M5 Slider part M6 2nd gantry part C1 Processing part C2 Control part W Board work P image (imaging the landed droplets)
Ps image (flying observation of ejected droplets)
Ln Discharged droplet QMn Landed droplet SMN Area VMn Volume (droplet amount)
LI Discharged reference droplet QI Landed reference droplet SI Reference droplet area VI Reference droplet volume (droplet volume)
α Area Volume conversion coefficient βxy Wetting property correction coefficient Ts Discharge time 1s Droplet amount measurement system HC Host computer G Measurement board preparation part GH Board holding part GM Relative movement part GC1 Processing part GC2 Control part RH Board transfer part Ws Measurement board

Claims (3)

It is a liquid drop amount measuring system that measures the amount of each droplet ejected from a plurality of inkjet nozzles provided in an inkjet coating device that lands a droplet at a predetermined position on a substrate.
A measurement substrate holding unit that holds a measurement substrate for landing each droplet ejected from the plurality of inkjet nozzles for which the amount of droplets is to be measured,
A reference nozzle that ejects a reference droplet that serves as a reference for measuring the amount of each droplet toward the measurement substrate, and a reference nozzle.
A relative moving unit that relatively moves the measurement board and the reference nozzle,
A reference droplet amount measuring unit for measuring the droplet amount of the reference droplets ejected from the reference nozzle, and a reference droplet amount measuring unit.
A substrate transfer unit that delivers the measurement substrate to the inkjet coating device, and
A host computer that transfers the droplet landing position information regarding the landing position of each of the droplets landed on the measurement substrate to the inkjet coating device.
An image acquisition unit that acquires an image including each of the droplets and the reference droplets ejected from the plurality of inkjet nozzles landed on the measurement substrate.
A droplet amount measuring unit for measuring the droplet amount of each droplet by measuring the area of each droplet contained in the image and then performing volume conversion is provided.
The droplet amount measuring unit is
A liquid drop area measuring unit that measures the area of each of the droplets contained in the image,
A conversion coefficient registration unit that registers in advance an area-volume conversion coefficient for converting the amount of each droplet from the area of each droplet that has landed on the measurement substrate.
A correction coefficient registration unit for registering a wettability correction coefficient for correcting the area of each droplet measured by the droplet area measurement unit for each location or section of the measurement substrate.
A conversion coefficient calculation unit that calculates the area-volume conversion coefficient based on the relationship between the area of the reference droplet landed on the measurement substrate and the amount of the droplet.
The wettability correction coefficient is calculated based on the ratio of the area of each reference droplet of the same amount of droplets landed on the measurement substrate to the area of the reference droplet landed on the representative location. Correction coefficient calculation unit and
A droplet amount calculation unit that calculates the droplet amount of each droplet based on the area of each droplet measured by the droplet area measurement unit, the area volume conversion coefficient, and the wettability correction coefficient. A liquid drop measurement system characterized by being equipped. The droplet amount measuring system according to claim 1, wherein each of the droplets to be measured for the liquid drop amount is ejected from the plurality of inkjet nozzles a plurality of times and landed. The first or second aspect of the present invention, wherein dummy droplets for slowing the drying rate of the droplets are coated around each of the droplets to be measured for the amount of the droplets. Drop model measurement system.

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