Ejection state inspection method, ejection state inspection apparatus, and liquid droplet inspection system

Abstract

The invention provides a technology capable of simultaneously checking the discharge amount of liquid droplets and checking the flying state. The present invention provides a discharge state inspection method, a discharge state inspection apparatus, and a droplet inspection system, the discharge state inspection method including: an ejection step of ejecting droplets from a discharge device (10) toward a weightometer (30); an event data acquisition step of acquiring event data of the liquid droplet ejected from the ejection device (10) by means of an event sensor (20); a measurement step in which weight value data of the droplets ejected in the ejection step is acquired from a weightometer (30); and an inspection step for inspecting the discharge amount of the discharge device (10) on the basis of the event data and the weight value data. In the inspection step, the flying abnormality of the ejection device (10) is inspected on the basis of the event data.

Description

TECHNICAL FIELD

[0001] The present application relates to a discharge state inspection method, a discharge state inspection device, and a droplet inspection system. BACKGROUND

[0002] Conventionally, a discharge device (or dispenser) that drips and applies a liquid material such as a medical liquid or liquid crystal is known. In such a discharge device, the discharge amount can be deviated due to hardening / denaturation of the liquid material, or a change in viscosity with a change in temperature of the liquid material, and the like. Therefore, the discharge amount of the liquid material is periodically measured by a weight meter or the like, and the discharge parameters are adjusted to correct the discharge amount (for example, refer to paragraph

[0033] of Patent Literature 1).

[0003] On the other hand, in Patent Literature 2, a method is proposed in which, in order to omit the measurement process using a weight meter, the amount of liquid crystal dripping is continuously fed back to a liquid crystal dropper in order to adjust the amount of liquid crystal dripping, based on an image of the dripping liquid crystal captured by a high-speed camera.

[0004] However, even if it is a high-speed camera, since it is only possible to capture several images of one droplet, there is a problem that it is difficult to correctly capture the droplet (refer to paragraph

[0004] of Patent Literature 3). In addition, the high-speed camera has a problem that as the speed becomes faster, the capacity of the image data also becomes larger, and the time taken for image processing also increases.

[0005] Therefore, in Patent Literature 3, a technical solution is proposed in which an event sensor is used instead of a high-speed camera, the event sensor photoelectrically converts a light signal, has a pixel that outputs a pixel signal, and outputs a temporal luminance change of the light signal as an event signal based on the pixel signal.

[0006] [Related Art Documents]

[0007] [Patent Literature]

[0008] Patent Literature 1: Japanese Patent Application Publication No. 2009-190012

[0009] Patent Literature 2: Japanese Patent Application Publication No. 2006-195402

[0010] Patent Literature 3: Japanese Patent Application Publication No. 2022-54057 SUMMARY

[0011] (PROBLEMS TO BE SOLVED BY THE INVENTION)

[0012] If the ejection device is used for a long time, flight abnormalities of liquid droplets can occur due to the influence of liquid material or the like adhering to the nozzle. If the measurement is performed by the weight meter in the state where the flight abnormalities occur, the ejection amount can not be correctly measured because the liquid droplets do not adhere to the weight meter. Specifically, because there are liquid droplets that do not adhere to the weight meter, the weight per droplet is incorrectly calculated, and thus the correction can not be appropriately performed.

[0013] Furthermore, if the flight direction or the flight speed of the liquid droplets changes, misalignment of the adhering position to the workpiece or satellite liquid droplets (unintended shot-like liquid droplets) can occur. In the case where the measurement of the ejection amount and the measurement of the flight direction or the flight speed are performed by different measurement machines, there is a problem that liquid material is wasted every time the measurement is performed by each machine.

[0014] Therefore, an object of the present application is to provide an ejection state inspection method, an ejection state inspection device, and a liquid droplet inspection system that can simultaneously perform the inspection of the ejection amount and the inspection of the flight state of liquid droplets.

[0015] (Technical means for solving the problem)

[0016] [1] An ejection state inspection method according to the present application, characterized by comprising the following steps: a shooting step of shooting liquid droplets from an ejection device toward a weight meter; an event data acquisition step of acquiring event data of the liquid droplets shot from the ejection device by an event sensor; a measurement step of acquiring weight value data of the liquid droplets shot in the shooting step from the weight meter; and an inspection step of inspecting the ejection amount of the ejection device based on the event data and the weight value data; in the inspection step, a flight abnormality of the ejection device is inspected based on the event data.

[0017] [2] The ejection state inspection method according to the above [1], characterized in that, in the inspection step, the number of liquid droplets having a flight abnormality is calculated based on the event data, and the average ejection amount per droplet of the ejection device is inspected based on the calculated number of liquid droplets.

[0018] [3] The ejection state inspection method according to the above [2], characterized in that, in the inspection step, liquid droplets having a flight speed abnormality are detected and inspected based on the event data.

[0019] [4] The ejection state inspection method according to the above [2] or [3], characterized in that, in the inspection step, the number of liquid droplets that do not adhere to the weight meter is detected based on the flight direction of the liquid droplets detected from the event data, and the ejection amount of the ejection device is inspected based on the number of liquid droplets after the number of liquid droplets that do not adhere to the weight meter is removed.

[0020] [5] The discharge state inspection method according to any one of [2] to [4], characterized in that, in the inspection process, a reference weight is calculated by multiplying the calculated number of droplets by a target discharge amount, the weight value data is compared with the reference weight, and it is determined that there is an abnormality when the difference exceeds a set threshold value.

[0021] [6] The discharge state inspection method according to any one of [1] to [5], characterized in that, in the inspection process, the following processes are performed:

[0022] (A) a process of labeling the detected droplets according to the event data;

[0023] (B) a process of detecting droplets having a flight speed abnormality according to the event data;

[0024] (C) a process of detecting the number of droplets not attached to the weight meter according to the flight direction of the droplets detected from the event data;

[0025] (D) a process of calculating the number of droplets having different labels among the droplets detected in the (B) and the (C); and

[0026] (E) a process of determining that there is a flight abnormality when the number of droplets calculated in the (D) is a certain number or more with respect to the number of droplets ejected in the ejection process.

[0027] [7] The discharge state inspection method according to [6], characterized by further comprising a process of inspecting the average discharge amount per droplet of the discharge device according to the number of droplets after the number of droplets calculated in the (D) is subtracted from the number of droplets ejected from the discharge device in the ejection process.

[0028] [8] The discharge state inspection method according to any one of [1] to [7], characterized in that, in the ejection process, one droplet ejected from the discharge device is less than the measurement resolution of the weight meter, and the droplet is repeatedly ejected from the discharge device at least until the measurement resolution of the weight meter is exceeded.

[0029] [9] The discharge state inspection method according to any one of [1] to [8], characterized in that, in the ejection process, the droplet is repeatedly ejected from the discharge device at least until 10 times the measurement resolution is exceeded.

[0030]

[10] The discharge state inspection device of the present invention, which has a storage device that stores a discharge state inspection program that inspects the discharge amount of a discharge droplet of a discharge device, and a processing device that executes the discharge state inspection program, is characterized in that the discharge state inspection program includes a unit that acquires event data of a droplet discharged from the discharge device facing the weight meter from an event sensor, a unit that acquires weight value data of the droplet discharged from the discharge device from the weight meter, and a droplet inspection unit that inspects the discharge amount of the discharge device based on the weight value data and the event data, and the droplet inspection unit inspects the flight abnormality of the discharge device based on the event data.

[0031]

[11] The discharge state inspection system of the present invention is characterized by having a discharge device that has a discharge port that discharges a liquid material in a droplet shape, a weight meter that measures the weight of the liquid material discharged from the discharge device and outputs weight value data, an event sensor that outputs event data based on the amount of change in the amount of light received from the light receiving range between the discharge port and the weight meter, and a discharge state inspection device that inspects the discharge amount of the discharge device based on the weight value data output from the weight meter, and the discharge state inspection device inspects the flight abnormality of the discharge device based on the event data.

[0032]

[12] In the discharge state inspection system of the above

[11] , the event sensor is configured to have a first event sensor and a second event sensor, the first event sensor is disposed in the X direction orthogonal to the Z direction toward the discharge device and the weight meter, and the second event sensor is disposed in the direction orthogonal to the Z direction toward the discharge device and the weight meter, and is the Y direction orthogonal to the X direction.

[0033] Effects of the Invention

[0034] According to the present invention, since the inspection of the discharge amount of a droplet and the inspection of the flight state can be performed at the same time, the liquid material wasted for the inspection of the discharge state can be reduced. BRIEF DESCRIPTION OF DRAWINGS

[0035] Figure 1 A diagram for explaining the droplet inspection system of the embodiment.

[0036] Figure 2 A diagram for explaining the detection range of the EVS camera of the embodiment.

[0037] Figure 3 A diagram for explaining the coating device of the embodiment.

[0038] Figure 4A main part cross-sectional side view of the discharge state inspection device of the embodiment.

[0039] Figure 5 A main part cross-sectional side view of the discharge state inspection device of the modification.

[0040] Figure 6 A flowchart of the inspection procedure of the embodiment. DETAILED DESCRIPTION

[0041] Hereinafter, a modification to implement the present application will be described.

[0042] As shown in Figure 1 , the droplet inspection system 1 of the embodiment is provided with a discharge device 10, an EVS camera 20, a weight meter 30, and a discharge state inspection device 40.

[0043] The discharge device 10 discharges a liquid material in a droplet form from a discharge port. As the discharge device 10, an air pressure type that discharges by using the action of compressed gas, a jet type that discharges by using the action of a rod that reciprocates in a liquid chamber, a plunger type that discharges by using the action of a plunger that slides in a measurement section, and the like can be used.

[0044] The EVS camera 20 is an event-based camera provided with an event sensor that photoelectrically converts a light signal and outputs a temporal luminance change of the light signal as an event signal (event data). The event sensor is an asynchronous sensor that outputs event data only at a time point at which an event occurs, and is also called an EVS (event-based vision sensor). A camera provided with a synchronous image sensor typified by a CCD camera outputs 1 frame (picture) of image data, that is, frame data, at a cycle of a vertical synchronization signal, in contrast to this, the event sensor (or EVS) detects a luminance change of each pixel and outputs only the changed data in combination with coordinate and time information, and thus high-speed and low-latency data output can be performed, and since the amount of data is also small, high-speed image processing can be performed.

[0045] The EVS camera 20 of the embodiment is provided with a storage device (not shown) that stores event data of a temporal luminance change of a droplet D ejected from the discharge device 10, and outputs the stored event data to the discharge state inspection device 40. The EVS camera 20 outputs coordinates xi and yi that show the position of a pixel at which an event occurs, and event data that associates a luminance change mi as an event with a time ti at which the event occurs. The EVS camera 20 is provided with a timer inside, and records the count value of the timer as the time ti of the event.

[0046] The EVS camera 20 of the embodiment is arranged in a direction (X direction or Y direction) orthogonal to the Z direction toward the discharge device 10 and the weight meter 30. The EVS camera 20 of the embodiment is provided with an illuminating device 21 having a plurality of light sources arranged in a ring shape to illuminate the liquid droplet D. The EVS camera 20 is arranged between the discharge device 10 and the weight meter 30 at a measurement position. If the liquid droplet D passes within the angle of view of the EVS camera 20, the change in brightness accompanying the movement of the liquid droplet D is detected as an event and stored in a storage device. The EVS camera 20 can also be constituted by two event-based cameras that capture the liquid droplet D from two directions orthogonal to each other (see FIG. 6 described later). Figure 5

[0047] The weight meter 30 is a device that measures the weight of the liquid droplet D discharged from the discharge device 10 and outputs the weight value data to the discharge state checking device 40, for example, an electronic balance. The weight meter 30 is provided with a measurement tray 31 to store the liquid droplet D from the discharge device 10.

[0048] The discharge state checking device 40 is a computer or programmable logic controller (PLC) or the like provided with a processing device 41, a storage device 42 storing a discharge state checking program P, and a communication device 43, and checks the discharge state of the discharge device 10 by executing the discharge state checking program P. The discharge state checking device 40 is electrically connected to an input device and an output device not shown. As the input device, for example, a keyboard or mouse can be used, and as the output device, for example, a display can be used. Furthermore, the discharge state checking device 40 is configured to be able to communicate with an external information terminal via the communication device 43.

[0049] The discharge state checking program P is provided with an event acquisition unit that acquires event data of the liquid droplet D discharged from the discharge device 10 arranged opposite the weight meter 30 from the EVS camera 20, a measurement discharge instruction unit that causes the discharge device 10 to discharge a liquid droplet D for measurement a predetermined number of times, a weight acquisition unit that acquires weight value data of the liquid droplet D discharged from the discharge device 10 from the weight meter 30, and a liquid droplet checking unit that checks the discharged liquid droplet based on the event data.

[0050] If the processing device 41 executes the event acquisition unit, the recording of the event data is started by the EVS camera 20. If the processing device 41 executes the measurement discharge instruction unit, a discharge instruction to discharge the liquid droplet D a predetermined number of times is transmitted to the discharge device 10. The discharge instruction can be configured to transmit the same number of instructions as the predetermined number of times, or can be configured to execute the discharge a predetermined number of times by one transmission of the discharge instruction. At this time, it is preferable to repeatedly discharge the liquid droplet D until an amount of 10 to 1000 times the measurement resolution of the weight meter 30 is reached.

[0051] ​The droplet inspection unit can calculate the number of droplets, the flight speed and the flight direction of the droplets from the event data, and check the discharge state of the discharge device 10 by comparing the event data with the appropriate droplet D m 's event data stored in advance in the storage device 42, and calculate the average discharge amount per 1 droplet to be discharged from the discharge device 10 or the discharge amount of the appropriate droplet D m 's event data stored in advance in the storage device 42, and calculate the average discharge amount per 1 droplet to be discharged from the discharge device 10 or the discharge amount of the appropriate droplet D

[0052] Figure 2 A diagram for illustrating the detection range 22 of the EVS camera 20. When checking the discharge state of the discharge device 10, the discharge device 10 is arranged at a distance of a predetermined interval above the weight meter 30, and the EVS camera 20 is disposed between the discharge device 10 and the weight meter 30. As shown in Figure 2 , it is preferable that the EVS camera 20 is arranged so that the detection range 22 is located more upward than the middle position of a straight line connecting the discharge port of the nozzle 11 of the discharge device 10 located at the measurement position and the measurement disc 31 of the weight meter 30. This is because the droplet D that has a flight abnormality is far from the vertical line passing through the center of the discharge port as the flight distance becomes longer, and thus it can not be possible to obtain the event data if the detection range 22 is set to the lower side.

[0053] The droplet inspection unit of the discharge state checking program P estimates the attachment position of the droplet D from the flight direction of the droplet D passing through the detection range 22. In Figure 2 , the attachment positions of the droplets D1 to D4 are estimated from the event data of the droplets D1 to D4 in the detection range 22, and thus it is determined that D1 and D2 are within the range of the measurement disc 31, and D3 and D4 are outside the range of the measurement disc 31. In the case where it is determined that the droplet D is attached outside the range of the measurement disc 31, the number of droplets discharged for measurement (command value) is subtracted by the number of droplets attached outside the range.

[0054] Furthermore, the ejection status inspection device 40 generates an event image based on event data output from the EVS camera 20, and detects droplets as the tracking target from the event image. The ejection status inspection device 40 performs tagging processing by attaching tags to the detected droplets in the manner of D1, D2, D3, etc. By attaching tags to the detected droplets, even if both the flight speed and flight direction are considered abnormal, multiple abnormal droplets with the same tag are not counted repeatedly, and the droplet count processing can be performed appropriately.

[0055] Furthermore, the discharge status inspection device 40 has the following function: generating a display droplet image for the operator to monitor the droplets, and displaying it on an output device such as a monitor (not shown). The display droplet image is generated, for example, based on a positive image based on a positive event and a negative image based on a negative event, using a known method (see Patent Document 3). Since event data is different from image data (frame data) in frame form that is output periodically in sync with a vertical synchronization signal, and is only output each time an event occurs, it is necessary to convert it into frame data in order to generate the display droplet image.

[0056] The detailed structure of the present invention will be described below with reference to embodiments, but the technical concept of the present invention is not limited to any embodiment.

[0057] <Example>

[0058] (Coating device 101)

[0059] like Figure 3 As shown, the coating apparatus 101 of this embodiment mainly comprises a liquid material dispensing device 110, a relative drive device 130 for moving the dispensing device 110 relative to a workpiece stage 140 on which the workpiece W is placed, a conveying device 120, a test spray coating stage 150, a coating control device 160, and a droplet inspection device 201. Furthermore, in Figure 3 For ease of explanation, the cover 180 is depicted with a dashed line, and some illustrations are omitted.

[0060] The dispensing device 110 is a jet-type dispensing device that applies inertial force to the liquid material by rapidly bringing the dispensing member (valve body) close to or colliding with the bottom surface (valve seat) of the liquid chamber, causing it to be ejected from the dispensing outlet. The dispensing device 110 has a nozzle 111 for dispensing the liquid material, and its operation is controlled by a coating control device 160. The liquid material dispensed from the nozzle 111 is applied to the workpiece W in droplets.

[0061] The relative driving device 130 includes an X driving device 131 that relatively moves the ejecting device 110 and the workpiece table 140 in the X direction, a Y driving device 132 that relatively moves the ejecting device 110 and the workpiece table 140 in the Y direction, and a Z driving device 133 that relatively moves the ejecting device 110 and the workpiece table 140 in the Z direction.

[0062] In the embodiment, the Y driving device 132 is provided to extend in the Y direction on the upper surface of the shelf table 170, and the X driving device 131 is provided to extend in the X direction on the Y driving device 132. The Z driving device 133 is provided on the X driving device 131, and the ejecting device 110 is provided on the Z driving device 133. The workpiece table 140 is provided to be parallel to the Y driving device 132 on the upper surface of the shelf table 170 and below the X driving device 131. Thus, the ejecting device 110 and the workpiece W on the workpiece table 140 can be relatively moved in the X direction, the Y direction, and the Z direction. The relative driving device 130 is controlled by the coating control device 160, and the tip of the nozzle 111 of the ejecting device 110 can be moved at an arbitrary speed toward an arbitrary position on the workpiece W. As the relative driving device 130, for example, a device in which an electric motor such as a servo motor or a step motor is combined with a ball screw, a device using a linear motor, a device in which power is transmitted by a belt or a chain, or the like can be used.

[0063] The conveyance device 120 is constituted by a rail 121, a transmission member (not shown), and a conveyance driving device 122. The rail 121 includes two members that extend in parallel in the Y direction. The rail 121 is configured such that the distance between the two members is the same as the distance of one side of the workpiece W. The transmission member that functions to convey the workpiece W in the extension direction of the rail 121 is provided to the rail 121. The transmission member can use a belt, a chain, or the like. The transmission member is driven by the conveyance driving device 122. As the conveyance driving device 122, an electric motor such as a servo motor or a step motor can be used. By the function of the transmission member driven by the conveyance driving device 122, the workpiece W is conveyed in the conveyance direction 123 along the rail 121. The conveyance device 120 is connected to the coating control device 160, and the speed of the conveyance, the start and stop of the conveyance, and the like are controlled.

[0064] The work table 140 is composed of a rectangular parallelepiped member, and is movable up and down by a lifting device (not shown). The work table 140 is disposed so as to be sandwiched between the rails 121 of the conveyance device 120. The width of the work table 140 in the X direction is slightly smaller than the distance between the rails 121 of the conveyance device 120, in a manner so as not to come into contact with the rails 121. When the workpiece W is being conveyed, the work table 140 is lowered to a position where it does not come into contact with the workpiece W. When the workpiece W is subjected to the coating work, the work table 140 is raised in a manner so as to sandwich and hold the workpiece W between the pressure plates (not shown) provided to the rails 121. In order to more surely hold the workpiece W, for example, a suction holding unit that holds the workpiece W by sucking air from a plurality of holes that are open from the inside of the work table 140 to the top can also be provided.

[0065] The test spray coating table 150 is disposed in a range movable by the relative driving device 130 in the vicinity of the work table 140 on the shelf table 170. The test spray coating table 150 has a test spray coating region on the surface where liquid material can be coated. Liquid material is coated on the test spray coating region before the start of the coating work, in order to remove dried liquid material from the tip of the nozzle. Furthermore, adjustment can also be performed so that the same conditions as the workpiece W are applied to the test spray coating region, and the liquid material to be coated on the workpiece W is made into a desired shape and size. Alternatively, a plate-shaped body for test spray coating can also be prepared separately, and the plate-shaped body for test spray coating can be held by using the above-described suction holding unit, to constitute a test spray coating work table.

[0066] The coating control device 160 is an information processing device (computer) that has a processing device, a storage device that stores a coating program and the above-described discharge state checking program P, and a communication device. The coating control device 160 controls the operation of the discharge device 110, the conveyance device 120, and the relative driving device 130 by executing the coating program. Furthermore, the coating control device 160 functions as the above-described discharge state checking device that checks the discharge state of the discharge device 110 by executing the discharge state checking program P. The coating control device 160 is electrically connected to an input device and an output device that are not shown. In the embodiment, the input device and the output device are constituted by one touch panel (not shown). Furthermore, the coating control device 160 can also be constituted by a plurality of control devices that are physically different, for example, by a first control device that has a storage device that stores a coating program, a processing device, and a communication device, and a second control device that has a storage device that stores a discharge state checking program P, a processing device, and a communication device.

[0067] In the coating apparatus 101 of the embodiment, an unillustrated camera and a length measuring device can be provided. The camera is constituted by, for example, a CCD camera, and is used to take an image of a component or an identification mark on the workpiece W, or a liquid material to be coated. The length measuring device is constituted by, for example, a laser displacement meter, and is used to measure a distance to a surface of the workpiece W, a surface of a component on the workpiece W, or a surface of a liquid material coated on the workpiece W.

[0068] The camera and the length measuring device are provided on the Z drive device 133 together with the discharge device 110, and are relatively movable with respect to the workpiece W on the workpiece table 140. The camera and the length measuring device can be integrally provided by a mounting plate. The camera and the measuring device are connected to the coating control device 160, and can control the operation or perform storage and processing of the measurement results. Image data taken by the camera and distance data measured by the length measuring device are used to confirm a state of the liquid material to be coated, to position the nozzle of the discharge device 110 with respect to the workpiece W, and so on.

[0069] The coating apparatus 101 of the embodiment is connected to an unillustrated teaching terminal, which can teach the coating control device 160 about a position of the relative drive device 130 or an operation of the discharge device 110, and so on. The coating control device 160 can arrange a plurality of teaching contents in association in sequence, and store and execute a coating program constituted as a whole. In other words, the coating control device 160 can operate the discharge device 110 or the relative drive device 130 in accordance with the teaching contents. As the teaching terminal, for example, a dedicated terminal having a simple display device and a plurality of switches, or a personal computer installed with dedicated software can be used. From the teaching terminal, an operation of the coating apparatus 101 can be started or stopped in accordance with a coating program stored in the coating control device 160. Instead of the teaching terminal, the above-mentioned coating control device 160 and the touch panel can be used for teaching.

[0070] An upper portion of the stand 170 provided with the discharge device 110, the workpiece table 140, the relative drive device 130, and so on is covered with a cover 180. By providing the cover 180, dust can be prevented from entering the coating apparatus 101, and accidental contact of the operator with the operating portions of the relative drive device 130, and so on can be prevented. In order to facilitate entry of the operator into the coating apparatus 101, a door that can be opened and closed can be provided in the cover 180. Further, the above-mentioned touch panel can be provided on an outer side surface of the cover 180, so that operation can be performed outside the cover 180. Further, an opening portion for carrying the workpiece W into and out of the cover 180 can be provided in the cover 180.

[0071] (Droplet inspection apparatus 201)

[0072] The droplet inspection apparatus 201 includes a frame 210, an EVS camera 220, and a weight meter 230.

[0073] The EVS camera 220 includes an event sensor (not shown) that photoelectrically converts a light signal, has a pixel that outputs a pixel signal, and outputs a temporal luminance change of the light signal as event data according to the pixel signal to the coating control apparatus 160, a storage device (not shown) that stores the event data, and a ring-shaped illumination device 221. The weight meter 230 is an electronic balance that has a measurement disc 231 and outputs a measured weight value data to the coating control apparatus 160.

[0074] Figure 4 A main part of the droplet inspection apparatus 201 is shown in a cross-sectional side view.

[0075] The frame 210 is a rectangular parallelepiped that has a space surrounded by an upper plate 211, four side plates 212, and a bottom plate 213. The EVS camera 220 that includes the ring-shaped illumination device 221 and a lens 222 is installed on the bottom surface of the upper plate 211, and the weight meter 230 is placed on the bottom plate 213. A circular through-hole 214 is provided on the upper plate 211 directly above the measurement disc 231. The through-hole 214 is sized to allow the discharge device 110 to enter, but is only required to be sized to allow a nozzle provided at the front end of the discharge device 110 to enter.

[0076] When the inspection process of performing confirmation of the discharge state is implemented, the relative drive device 130 is driven to move the discharge device 110 vertically upward toward the measurement disc 231 of the weight meter 230. Then, the Z drive device 133 is operated to move the discharge device 110 downward, and further to move the discharge device 110 from the through-hole 214 of the droplet inspection apparatus 201 into the inside thereof.

[0077] By detecting the dispensing device 110 using the EVS camera 220, the relationship between the coordinates calculated based on the detection event of the EVS camera 220 (inspection coordinates) and the coordinates of the relative drive device 130 corresponding to these coordinates (coating coordinates) can be obtained. After the EVS camera 220 detects the front end position of the dispensing device 110, the dispensing device 110 is moved upwards, and when the front end of the nozzle 111 reaches the detection limit position at the top of the EVS camera 220, the coordinates of the relative drive device 130 at this time are stored in the storage device as reference coordinates (measurement position). However, the inspection process can be performed with the dispensing device 110 at the reference coordinate or at a position descending from the reference coordinate, or at a position ascending from the reference coordinate (i.e., any position vertically above the measuring disk 231 can be used as the measurement position). In any case, since the coordinates of the EVS camera 220 (inspection coordinates) and the coordinates of the relative drive device 130 (coating coordinates) are obtained, it is possible to determine whether the droplet is attached to the measuring disk 231 based on the ejection direction of the droplet detected by the EVS camera 220.

[0078] Figure 5 This is a cross-sectional side view of the main part of a modified droplet inspection device 201A. The droplet inspection device 201A includes a first EVS camera 220A for capturing images in a first direction (X direction) and a second EVS camera 220B for capturing images in a second direction (Y direction) orthogonal to the first direction. The first EVS camera 220A includes an annular illumination device 221A and a lens 222A. Similarly, the second EVS camera 220B also includes an annular illumination device 221B and a lens 222B. By acquiring event data of droplets D passing through the imaging range (XZ plane) in the X and Z directions with the first EVS camera 220A, and acquiring event data of droplets D passing through the imaging range (YZ plane) in the Y and Z directions with the second EVS camera 220B, deviations in the flight direction in the X and Y directions can be detected. Furthermore, with a single EVS camera, it is necessary to correct for the deviation in the depth direction of the detection data (i.e., the front side is detected larger and the deep side is detected smaller). However, in the variant example using two EVS cameras 220A and 220B, the flight state of the droplet can be detected more accurately.

[0079] (Inspection process)

[0080] The inspection process is carried out via a predetermined calibration cycle or a user instruction at any time. The inspection cycle can be set, for example, by user-inputted time information or the number of workpieces W to be processed.

[0081] use Figure 6 The flowchart illustrates the inspection process.

[0082] When the inspection process is started, the coating control device 160 drives the relative driving device 130 to move the discharging device 110 to a measurement position above the weight meter 230 (S101). Next, the coating control device 160 executes the above-mentioned event acquisition unit to start sensing by the EVS camera 220 (S102). Thereby, event data of a change in brightness accompanying movement of the liquid droplet D discharged from the discharging device 110 can be stored in the storage device of the EVS camera 220.

[0083] The coating control device 160 executes the measurement discharging instruction unit to execute an ejection process of continuously discharging a liquid material for measurement from the discharging device 110 toward the measurement disc 231 of the weight meter 230 in a droplet shape (S103). In this ejection process, since one droplet discharged from the discharging device 110 is less than the measurement resolution of the weight meter 230 in weight, the droplet D is repeatedly discharged from the discharging device 110 until at least 10 times the measurement resolution of the weight meter 230 is exceeded.

[0084] After the ejection process is completed, the coating control device 160 acquires a series of event data from the EVS camera 220 and weight value data from the weight meter 230, and stores them in the storage device (S104). Here, the event data can also be configured to be sequentially transmitted from the EVS camera 220 to the coating control device 160 midway through the ejection process.

[0085] The coating control device 160 executes the droplet inspection unit to generate an event image from the event data, and detect a droplet that is a tracking target from the event image and attach a label (S105).

[0086] The coating control device 160 executes the droplet inspection unit to count the number of droplets that have abnormalities in the flying state from the event data to inspect the discharging state of the discharging device 110 (S106). In detecting the number of droplets that have abnormalities, the speed of each droplet D is also calculated from the event data, and a droplet whose speed is abnormal is determined to be speed abnormal. The coating control device 160 stores event data of a droplet D that is discharged under appropriate discharging conditions with the same discharging amount as before and the speed of the droplet D m m in the storage device. Then, the speed of the droplet D m (referential speed) is compared with the speed of each droplet D that is measured, and in the case where the difference is equal to or less than a threshold value (for example, ±5% of the referential speed), it is determined to be normal, and in the case where it exceeds the threshold value, it is determined to be abnormal, and the determination result is stored in the storage device. Here, the number of droplets after subtracting the number of droplets determined to be abnormal from the number of droplets discharged in the ejection process can also be used to perform the droplet weight inspection (S108) described later.

[0087] ​The coating control device 160 executes a droplet inspection unit that detects the flight direction of each droplet D based on the event data and performs inspection (S107). Specifically, the flight direction of the droplet D is calculated based on the coordinate data of the droplet D at a plurality of times, and it is determined to be normal when the measurement disc 231 is present on the extension line of the calculated flight direction and to be abnormal when the measurement disc 231 is not present on the extension line of the flight direction, and the determination result is stored in the storage device. Alternatively, it can be configured such that it is determined to be normal when the difference between the calculated flight direction and the vertical direction is equal to or less than a threshold value (for example, ±5%), and to be abnormal when it exceeds the threshold value, and the determination result is stored in the storage device.

[0088] The coating control device 160 executes a droplet inspection unit that inspects the weight of the droplet D based on the weight value data (S108). The coating control device 160 calculates the average discharge amount per 1 droplet using the number obtained by subtracting the number of droplets that are not attached to the measurement disc 231 calculated in S107 from the total number of droplets detected in S106. Alternatively, the average discharge amount per 1 droplet can be calculated by dividing the discharge amount by the number obtained by subtracting the number of droplets determined to be abnormal in speed in S106 and the number of droplets determined not to be attached to the measurement disc 231 in S107 from the number of discharge times specified by the measurement discharge instruction unit. In this case, in the case where the droplets with the same label are determined to be abnormal in S106 and S107, repeated counting is avoided.

[0089] The calculated average discharge amount per droplet is compared with the average target discharge amount per time (the amount of one discharge that should be present) that should be discharged by the execution of the measurement discharge instruction unit, and it is determined to be normal when the difference is equal to or less than a threshold value (for example, ±5%) and to be abnormal when it exceeds the threshold value, and the determination result is stored in the storage device. Alternatively, the amount of one discharge that should be present (target discharge amount) and the number obtained by multiplying the number of droplets attached to the measurement disc 231 can be used as a reference weight, the weight value data is compared with the reference weight, and it is determined to be normal when the difference is equal to or less than a threshold value (for example, ±5%) and to be abnormal when it exceeds the threshold value.

[0090] In a case where no abnormality is detected in any of the droplet number check of S106, the flight direction check of S107, and the droplet weight check of S108, a message notifying that no abnormality is detected is displayed on the output device (not shown), and a normally ended case is stored in the storage device together with an ending time (S109, 110). In a case where an abnormality is detected in any of the droplet number check of S106, the flight direction check of S107, and the droplet weight check of S108, a message notifying the content of the abnormality is displayed on the output device (not shown), and an abnormal end is stored in the storage device together with an ending time (S109, 111). In S109, a reference number of abnormal droplets can be set in the droplet number check of S106, the flight direction check of S107, and the droplet weight check of S108, respectively, and an abnormality can be determined only in a case where the reference number is exceeded. For example, whether or not the number of droplets is abnormal can be determined based on whether or not the number of droplets is less than a reference number (for example, 2% or 3%) determined by multiplying the total number of ejection instructions issued in the ejection process by a certain ratio.

[0091] According to the coating device 101 of the above-described embodiment, the plurality of droplets D ejected toward the weight meter 230 can be detected by the EVS camera 220, whereby the flight state of the droplets can be confirmed, and the droplets used for confirming the flight state can be measured by the weight meter 230 for correction of the ejection amount. Therefore, since the liquid material ejected for correction of the ejection amount is not wasted, and the time required for ejection amount adjustment and confirmation of the flight state can be shortened, improvement in productivity is facilitated.

[0092] Further, since the amount of data processed by the event data acquired by the EVS camera 220 is smaller than that of the frame data, image processing of the droplets D can be performed at high speed. That is, even in an ejection device that ejects droplets several tens or several hundreds of times or more per second, the droplets can be tracked by the EVS camera 220, and therefore, droplets not attached to the measurement disc 231 can be removed, and the average ejection amount per time can be accurately calculated.

[0093] The above-described preferred embodiments of the present application have been described, but the technical scope of the present application is not limited to the above-described embodiments. Various changes and modifications can be added within the scope of the technical idea of the present application, and a mode to which such changes or modifications are added is also included in the technical scope of the present application.

[0094] For example, in the liquid drop number inspection (S106), the total number of the liquid drops ejected in the ejection process can not be counted, and only the number of the liquid drops determined to have the flight speed abnormality can be counted, and it can be determined that there is an abnormality or not based on whether or not the number is less than a reference number (for example, 2% or 3%) obtained by multiplying the number of times of ejection in which the ejection instruction is issued in the ejection process by a certain percentage. Specifically, a configuration can be disclosed in which, in a case where the number of times of ejection in which the ejection instruction is issued in the ejection process is 1000 times, it is determined that there is an abnormality only in a case where the number of the liquid drops determined to have the flight speed abnormality is more than 20 drops (reference number 2%) or 30 drops (reference number 3%).

[0095] As another modification, for example, the following process can be added: the number of the liquid drops that should be ejected per unit time (target liquid drop number) is set, and it is determined whether or not there is an abnormality based on whether or not the difference between the total number of the liquid drops counted by the liquid drop inspection unit and the target liquid drop number is less than a value obtained by multiplying the target liquid drop number by a certain percentage (for example, 2% or 3%).

[0096] SYMBOL DESCRIPTION

[0097] 1: liquid drop inspection system

[0098] 10: ejection device

[0099] 11: nozzle

[0100] 20: EVS camera

[0101] 21: illumination device

[0102] 30: weight meter

[0103] 31: measurement disc

[0104] 40: ejection state inspection device

[0105] 101: coating device

[0106] 110: ejection device

[0107] 111: nozzle

[0108] 201: liquid drop inspection device

[0109] 220: EVS camera

[0110] 221: illumination device

[0111] 230: weight meter

[0112] 231: measurement disc

[0113] D: liquid drop

[0114] W: workpiece

Claims

1. A discharge state checking method characterized by comprising: comprising: an ejection process of ejecting a droplet from a discharge device toward a gravimeter; an event data acquisition process of acquiring event data of the droplet ejected from the discharge device by an event sensor; a measurement process of acquiring weight value data of the droplet ejected in the ejection process from the gravimeter; and an inspection process of inspecting a discharge amount of the discharge device based on the event data and the weight value data, in the inspection process, a flight abnormality of the discharge device is inspected based on the event data.

2. The discharge state inspection method according to claim 1, wherein in the inspection process, a number of droplets having the flight abnormality is calculated based on the event data, and an average per-droplet discharge amount of the discharge device is inspected based on the calculated number of droplets.

3. The discharge state inspection method according to claim 2, wherein in the inspection process, droplets having a flight speed abnormality are detected based on the event data and inspected.

4. The discharge state inspection method according to claim 2, wherein in the inspection process, a number of droplets not attached to the gravimeter is detected based on a flight direction of the droplets detected from the event data, and a discharge amount of the discharge device is inspected based on a number of droplets after the number of droplets not attached to the gravimeter is removed.

5. The discharge state inspection method according to claim 2, wherein in the inspection process, a reference weight is calculated by multiplying the calculated number of droplets by a target discharge amount, and the weight value data and the reference weight are compared, and in a case where a difference amount exceeds a set threshold value, it is determined that there is an abnormality.

6. The discharge state inspection method according to claim 1, wherein in the inspection process, each of the following processes is executed: (A) a process of attaching a label to a detected droplet based on the event data; (B) a process of detecting a droplet having a flight speed abnormality based on the event data; (C) a process of detecting a number of droplets not attached to the gravimeter based on a flight direction of the droplets detected from the event data; (D) a process of calculating a number of droplets having different labels among the droplets detected in the (B) and the (C); and (E) a process of determining that there is a flight abnormality in a case where a proportion of the number of droplets calculated in the (D) to a number of droplets ejected in the ejection process is a certain number or more.

7. The discharge state inspection method according to claim 6, wherein further comprising a process of inspecting an average per-droplet discharge amount of the discharge device based on a number of droplets after the number of droplets calculated in the (D) is removed from a number of droplets ejected in the ejection process.

8. The discharge state inspection method according to any one of claims 1 to 7, wherein in the ejection process, one droplet ejected from the discharge device is a weight smaller than a measurement resolution of the gravimeter, and the droplet is repeatedly ejected from the discharge device at least until the measurement resolution of the gravimeter is exceeded.

9. The discharge state inspection method according to claim 8, wherein In the ejection process, the liquid droplets are repeatedly ejected from the ejection device at least until 10 times the measurement resolution is exceeded.

10. An ejection state inspection apparatus comprising: a storage device storing an ejection state inspection program for inspecting an ejection amount of an ejection device that ejects liquid droplets; and a processing device that executes the ejection state inspection program, the ejection state inspection apparatus characterized by the ejection state inspection program including: a unit that acquires event data of liquid droplets ejected from the ejection device facing the weight meter from an event sensor; a unit that acquires weight value data of the liquid droplets ejected from the ejection device from the weight meter; and a liquid droplet inspection unit that inspects an ejection amount of the ejection device from the weight value data and the event data, the liquid droplet inspection unit inspecting a flight abnormality of the ejection device from the event data.

11. A droplet inspection system characterized by, the ejection state inspection apparatus comprising: an ejection device having an ejection port that ejects a liquid material in a droplet shape; a weight meter that measures a weight of the liquid material ejected from the ejection device and outputs weight value data; an event sensor that outputs event data based on a change amount of an amount of light received from a light receiving range between the ejection port and the weight meter; and an ejection state inspection apparatus that inspects an ejection amount of the ejection device from the weight value data output by the weight meter, the ejection state inspection apparatus inspecting a flight abnormality of the ejection device from the event data.

12. The liquid droplet inspection system according to claim 11, wherein the event sensor is configured to include a first event sensor and a second event sensor, the first event sensor is disposed in an X direction orthogonal to a Z direction facing the ejection device and the weight meter, the second event sensor is disposed in a direction orthogonal to the Z direction facing the ejection device and the weight meter, and is a Y direction orthogonal to the X direction.

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