Liquid drop detection system and method

Abstract

The invention relates to the technical field of measuring instruments, in particular to a liquid drop detection system and method. The liquid drop detection system comprises a dripping area used for a to-be-detected nozzle to drip liquid drops; the detection area is provided with a liquid drop detection unit and is used for collecting a morphology image of the liquid drop; the liquid drop detection plane is used for bearing dripping liquid drops; the carrying module is used for driving the liquid drop detection plane to move between the dripping area and the detection area; and the processing unit is used for processing the morphology image of the liquid drop and also used for controlling the moving direction and distance of the carrying module. When liquid drop detection is carried out, through the movement of the liquid drop detection plane between the dripping area and the detection area, a sample to be detected does not need to be collected from a liquid drop generation position and then transferred to an independently arranged liquid drop detection instrument for detection, the liquid drop transfer distance and time are shortened, the influence of liquid drop volatilization on a detection result is reduced, and the detection accuracy is improved. The real-time performance of detection is improved, and the risk of distortion of a detection result is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of measuring instruments, in particular to a droplet detection system and method. BACKGROUND

[0002] In industrial production and scientific research, it is often necessary to measure the shape and surface profile of liquid droplets to understand their volume, height, contact angle, and other information. These data are of great significance for controlling processes such as inkjet printing, drug titration, microfluidic device operation, and coating processes.

[0003] In the inkjet printing industry, the printer's nozzle will continuously eject tiny droplets of ink. The size, regularity of shape, and whether the droplets split into multiple small droplets (i.e., satellite droplets) during flight will directly affect the clarity and quality of the printed image. To ensure stable printing results, manufacturers need to regularly detect the droplets ejected by the nozzle. If a droplet becomes skewed or has an excessively large volume, it may cause stripes or blurring in the printed image, so it is necessary to observe its morphology to determine whether the nozzle is working properly.

[0004] For example, in the medical detection field, there is a common rapid diagnostic test paper, such as blood glucose test paper or early pregnancy test paper, which requires a drop of blood or urine to be dropped on a designated area. The spreading speed and coverage of the liquid on the test paper will affect the accuracy of the reaction result. If the droplet spreads unevenly or does not fully soak the detection area due to surface tension issues, it may lead to misjudgment. Therefore, during the design and production of test paper, the morphological changes of the droplet on the material surface need to be observed and analyzed to ensure that the liquid flows and distributes as expected.

[0005] In the food packaging industry, there are also similar applications. For example, when filling beverages, there may be a small amount of liquid residue on the bottle opening, forming tiny droplets. These droplets may breed bacteria or corrode the packaging after the cap is sealed. Therefore, manufacturers will simulate the droplet process on the production line to observe whether the liquid will flow back into the bottle quickly after dropping onto the bottle opening or will remain as isolated droplets for a long time. By recording the spreading, retraction, and residence of the droplet after dropping using a high-speed camera, the bottle opening design or liquid formulation can be optimized to reduce residue.

[0006] In the quality detection of automobile windshield coating, in order to improve the hydrophobicity of the glass and enable it to quickly drain rainwater in rainy weather, a layer of anti-fog or hydrophobic agent is sprayed on the surface. During detection, the staff will use a dropper to drop a small drop of water on the glass surface and then observe the shape of the water droplet in a stationary state. If the coating is uniform and effective, the water droplet will have a high degree of sphericity, with a rounded edge and no spreading; if the coating is damaged or uneven in thickness, the water droplet will spread locally or deform. By analyzing the profile and contact angle of the water droplet after dropping through photography, it can be determined whether the coating is qualified.

[0007] In the production of waterproof coatings for electronic products, a very thin layer of hydrophobic material is coated onto the screen or casing of devices such as mobile phones and watches to improve their water-repellent properties. One way to test the effectiveness of this coating is to observe the shape of a water droplet on its surface. If the coating is uniform and intact, the water droplet will be nearly spherical with a large contact angle; if the coating is defective, the water droplet will spread out more. By photographing the shape of the water droplet and measuring its contact angle, the quality of the coating can be determined.

[0008] In pesticide spraying tests, the pesticide solution is sprayed from the nozzle and falls onto the leaf surface as small droplets. Researchers are concerned with whether these droplets spread evenly, roll off easily, or evaporate. If the droplets quickly shrink into a spherical shape after falling, it indicates that the leaf surface is too hydrophobic, making it difficult for the pesticide to adhere; if the droplets spread too far apart, it may lead to pesticide runoff. By photographing and analyzing the final shape of the droplets after they fall, it is possible to select appropriate adjuvants to improve the wetting properties of the pesticide solution.

[0009] To obtain the three-dimensional morphology of droplets, a common method is to scan the surface of the falling droplet using optical equipment. One approach is to use a separate droplet detection instrument (such as a white light interferometer) to detect the surface structure of the droplet. This instrument, based on the principle of light interference, can obtain a high-precision surface profile image and is suitable for applications requiring high measurement accuracy.

[0010] However, in practice, several significant problems have been found with using white light interferometers for droplet morphology detection. Due to the structural limitations of the equipment, the sample to be tested typically needs to be placed on a fixed platform, requiring a relatively stable and flat surface. The transfer of the droplet from its formation location to the measurement platform takes time, a process known as droplet transport. This prolonged transport time not only affects overall detection efficiency but also exposes the droplet to the environment for an extended period. Especially in environments with high temperatures or strong airflow, droplets are prone to evaporation, leading to volume reduction and shape changes. Consequently, even with high subsequent measurement accuracy, the results cannot accurately reflect the original state of the droplet upon formation, resulting in inaccurate detection results. Furthermore, due to the fluidity of the droplet, even slight vibrations or tilting during transport can cause morphological changes, further exacerbating measurement distortion. Therefore, existing methods for droplet morphology detection using white light interferometers exhibit shortcomings such as distorted results and insufficient real-time performance when dealing with volatile liquids or applications requiring rapid response. Summary of the Invention

[0011] The purpose of this invention is to overcome the problems of long transport time, easy evaporation of droplets leading to distorted detection results, and insufficient real-time performance when using a separately set droplet detection instrument for droplet detection, and to provide a droplet detection system and method.

[0012] In a first aspect, the present invention provides a droplet detection system, comprising: a droplet area for a nozzle to drop droplets; a detection area having a droplet detection unit for acquiring droplet morphology images; a droplet detection plane for carrying the droplets; a transport module for moving the droplet detection plane between the droplet area and the detection area; and a processing unit for processing the droplet morphology images and controlling the movement direction and distance of the transport module.

[0013] Preferably, the transport module includes a plate stage and a movable base. The plate stage is used to place the droplet detection plane, and the movable base is used to move the plate stage.

[0014] Preferably, the droplet detection system also includes a vibration damping platform to provide vibration damping for the droplet detection system.

[0015] Preferably, the droplet detection plane has optical properties where the reflectivity is higher than the transmittance.

[0016] Preferably, the droplet detection unit uses a white light detection head, and the processing unit uses an image processing algorithm to process the white light interference image of the droplet to obtain the three-dimensional morphology information of the droplet.

[0017] Preferably, the droplet detection system further includes an image acquisition unit for acquiring images of the droplet positions on the droplet detection plane. The processing unit further processes the droplet position images acquired by the image acquisition unit.

[0018] Preferably, the nozzle to be tested includes several nozzles. The processing unit can independently control any nozzle of the nozzle to be tested.

[0019] In a second aspect, the present invention provides a method for detecting droplets, comprising: S1, the relative positions of the calibrated droplet area, detection area, droplet detection plane, and droplet detection unit; among which, The dripping area is used for the droplets falling from the nozzle to be tested. The detection area is equipped with a droplet detection unit for acquiring images of the droplet morphology; The droplet detection plane is used to catch the falling droplets and can move between the falling area and the detection area; S2. In the dripping area, control the nozzle to be tested to drip droplets onto the droplet detection plane; S3. Control the movement of the droplet detection plane to move the droplet from the dropping area to the detection area; S4. Control the droplet detection unit to acquire droplet morphology images, process and output the droplet morphology images acquired by the droplet detection unit.

[0020] Preferably, S1 further includes: calibrating the relative position of the image acquisition unit by acquiring position images of the droplets on the droplet detection plane through the image acquisition unit.

[0021] Preferably, in S1, the calibration of the relative position of the detection area and the calibrated droplet detection unit further includes calibrating the focal plane and focal point of the calibrated droplet detection unit.

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This invention provides a droplet detection system and method. During droplet detection, the droplet detection plane moves between the droplet area and the detection area, eliminating the need to collect the sample from the droplet generation location and transport it to a separately designed droplet detection instrument for droplet morphology detection. This shortens the distance the droplet needs to travel from its generation location to the detection location. The droplet detection unit acquires morphological images of the droplets in the detection area; the processing unit processes and outputs these images to obtain three-dimensional morphological information such as the droplet's volume, diameter, and height. This invention enables rapid detection of minute droplets, reduces the impact of droplet evaporation on the detection results, improves the real-time performance of the detection, and reduces the risk of distorted detection results.

[0023] 2. The droplet detection system and method provided by this invention can detect droplets in each nozzle of a multi-nozzle nozzle head. By acquiring the morphological image of the droplets falling from each nozzle, the volume, diameter, and height of the droplets can be obtained, enabling rapid detection of tiny droplets. This reduces the impact of droplet evaporation on the detection results, improves the real-time performance of the detection, and lowers the risk of result distortion. This invention can achieve rapid detection of large-area droplet arrays and can also be used for nozzle consistency detection and evaluation in multi-nozzle nozzle heads.

[0024] 3. The droplet detection system provided by this invention can be integrated as a separate module into existing devices (such as inkjet printers). After the droplet system of the existing device drops the droplet, it can perform real-time online droplet morphology detection. Compared with the traditional droplet detection equipment that uses a separate droplet detection instrument, this improves the convenience of detection. Attached Figure Description

[0025] Figure 1 This is a diagram showing the composition of the droplet detection system of the present invention.

[0026] Figure 2 This is a schematic flowchart of the droplet detection method according to Embodiment 2 of the present invention.

[0027] Marked in the image: 101-Droplet area, 102-Detection area, 110-Transport module, 111-Slab support stage, 112-Moving base, 120-Droplet detection unit, 130-Droplet detection plane, 150-Image acquisition unit, 160-Vibration damping platform, 170-Support frame, 200-Nozzle to be tested. Detailed Implementation

[0028] The present invention will now be described in further detail with reference to specific embodiments. However, this should not be construed as limiting the scope of the present invention to the following embodiments; all technologies implemented based on the content of the present invention fall within the scope of the present invention.

[0029] Unless otherwise specified, the use of terms such as "upper," "lower," "left," "right," "center," "inner," and "outer" to indicate orientation or positional relationships in the description of specific embodiments of the present invention is based on the orientation or positional relationships shown in the accompanying drawings, or the orientation or positional relationship in which the product / equipment / device is typically placed during use. These terms are merely for the purpose of facilitating the description of the present invention or simplifying the description in specific embodiments, enabling those skilled in the art to quickly understand the solution, and do not indicate or imply that a particular device / component / element must have a specific orientation, or be constructed and operated in a specific positional relationship. Therefore, they should not be construed as limitations on the present invention.

[0030] Furthermore, the use of terms such as "horizontal," "vertical," "suspended," and "parallel" does not imply that the corresponding device / component / element must be absolutely horizontal, vertical, suspended, or parallel, but rather that it can be slightly tilted or have a deviation. For example, "horizontal" merely means that its direction is more horizontal relative to "vertical," not that the structure must be completely horizontal, but that it can be slightly tilted. Alternatively, it can be simplified to mean that the corresponding device / component / element, when set in a "horizontal," "vertical," "suspended," or "parallel" direction, can have an error / deviation of ±10% relative to the corresponding direction, more preferably within ±8%, more preferably within ±6%, more preferably within ±5%, and more preferably within ±4%. As long as the corresponding device / component / element is within the error / deviation range, it can still achieve its function in the present invention.

[0031] Furthermore, the use of terms such as "first," "second," and "third" in terminology is merely for distinguishing descriptions of identical or similar components and should not be interpreted as emphasizing or implying the relative importance of a particular component.

[0032] Furthermore, in the description of the embodiments of the present invention, "several", "more than", and "a number of" represent at least two. The number can be any number, such as 2, 3, 4, 5, 6, 7, 8, or 9, and can even exceed nine.

[0033] Furthermore, in the description of the technical solution of this invention, unless otherwise explicitly specified / limited / restricted, the terms "set up," "install," "connect," "link," "provided with," "laid out," and "arranged" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to common connection methods in the art, such as welding, riveting, bolting, and threaded connections. Such connections can be mechanical, electrical, or communication connections; they can be direct connections or indirect connections through an intermediate medium; and they can refer to the internal communication between two components.

[0034] This invention provides a droplet detection system. See also: Figure 1 The droplet detection system includes: a droplet area 101, a detection area 102, a droplet detection plane 130, a droplet detection unit 120, a transport module 110, and a processing unit.

[0035] The dripping area 101 is used for the nozzle 200 to drip liquid. The detection area 102 is equipped with a droplet detection unit 120 for acquiring images of the droplet's shape. The droplet detection plane 130 is used to support the dripping droplets. The transport module 110 can move the droplet detection plane 130 between the dripping area 101 and the detection area 102.

[0036] The processing unit acquires images of the droplet's morphology and calculates its volume, diameter, height, and other three-dimensional morphological information. The processing unit also controls the direction and distance of movement of the transport module 110.

[0037] When using the droplet detection system provided by this invention for droplet detection, the movement of the droplet detection plane 130 between the droplet area 101 and the detection area 102 eliminates the need to collect the sample from the droplet generation location and transport it to a separately set droplet detection instrument for droplet morphology detection, thus shortening the distance the droplet needs to travel from the generation location to the detection location. The droplet detection unit 120 acquires morphology images of the droplets in the detection area 102; the processing unit processes the morphology images of the droplets to obtain three-dimensional morphology information such as the droplet's volume, diameter, and height. This invention achieves rapid detection of tiny droplets, reduces the impact of droplet evaporation on the detection results, improves the real-time performance of the detection, and reduces the risk of distorted detection results.

[0038] In some embodiments, the transport module 110 includes a substrate stage 111 and a movable base 112. The substrate stage 111 is used to place the droplet detection plane 130, and the movable base 112 is used to move the substrate stage 111. The substrate stage 111 is disposed on the movable base 112. The side of the substrate stage 111 away from the movable base 112 is used to place the droplet detection plane 130. The movable base 112 is communicatively connected to the processing unit and can change its moving direction and moving distance in response to the control of the processing unit, so that all droplets on the droplet detection plane 130 can be acquired by the droplet detection unit 120 to obtain droplet morphology images.

[0039] The movable base 112 can adjust its attitude in three-dimensional space. Specifically, the movable base 112 can be a six-axis micro-motion platform, a three-axis stabilization platform, a magnetic levitation platform, a pneumatic vibration isolation platform, or any other platform capable of high-precision attitude adjustment in three-dimensional space. Droplets falling onto the droplet detection plane 130 are prone to deformation or sliding under the influence of gravity due to the tilt of the detection plane 130, altering the droplet's morphology and affecting the detection results. The movable base 112 can adjust its attitude to ensure the droplet detection plane 130 is horizontal, reducing the probability of changes in droplet morphology.

[0040] In some embodiments, the droplet detection system further includes a vibration damping platform 160 for providing vibration damping for the droplet detection system. The transport module 110 is disposed on the vibration damping platform 160, enabling the transport module 110 to smoothly transport the droplet detection plane 130, reducing the shaking of the droplet detection plane 130 during transport, reducing the possibility of damage to the morphology of the droplets on the droplet detection plane 130 due to external vibrations during transport, and improving the accuracy of the detection results.

[0041] In some embodiments, the droplet detection unit 120 may employ a white light detection head, the structure of which is the same as that of a conventional white light interferometer, capable of acquiring a white light interference image of the droplet. The processing unit uses image processing algorithms to process the white light interference image of the droplet to obtain three-dimensional morphological information such as the droplet's volume, diameter, and height.

[0042] In some embodiments, the droplet detection plane 130 has optical characteristics of high reflectivity and low transmittance, that is, the reflectivity of the droplet detection plane 130 is higher than its transmittance, which is beneficial for reflecting the white light emitted by the droplet detection unit 120 and improving the quality of the white light interference image of the droplet in the acquisition by the droplet detection unit 120.

[0043] See Figure 1In some embodiments, the droplet detection system further includes an image acquisition unit 150 for acquiring position images of droplets on the droplet detection plane 130. The processing unit controls the moving direction and distance of the transport module 110 and processes the droplet position images acquired by the image acquisition unit 150.

[0044] The image acquisition unit 150 can acquire images of the droplet's position in real time and online. The processing unit can determine the droplet's real-time position based on the images acquired by the image acquisition unit 150, and then control the movement direction and distance of the transport module 110 according to the droplet's real-time position, moving the droplet detection plane 130 to the detection area 102. The processing unit can control the image acquisition unit 150 to acquire images and determine the droplet's position based on the images acquired by the image acquisition unit 150.

[0045] In some embodiments, the nozzle 200 to be tested includes a plurality of nozzles. The processing unit is capable of independently controlling any nozzle of the nozzle 200 to be tested. When the liquid supply unit supplies liquid to the nozzle 200 to be tested and the processing unit is communicatively connected to the nozzle 200 to be tested, the processing unit is capable of controlling the nozzle of the nozzle 200 to operate in a specific manner, such as the nozzle or nozzle dripping liquid individually, simultaneously, or in a specific timing sequence.

[0046] When the nozzle 200 to be tested includes several nozzles, the droplet detection system can not only perform droplet detection on each nozzle of the nozzle 200 to be tested, but also determine the consistency of the nozzle 200 to be tested based on the droplet detection results of each nozzle of the nozzle 200 to be tested.

[0047] In some embodiments, the printhead to be tested can be any printhead that sprays, drips, or otherwise forms droplets, such as the printhead of an inkjet printer or a dispensing printhead.

[0048] The droplet detection system can be used as a standalone detection system to detect droplets on the printhead 200 to be tested, or it can be integrated as a functional component into an existing device (such as an inkjet printer) to perform real-time, online droplet detection on printheads 200 that are not removable or inconvenient to remove from the existing device.

[0049] When the droplet detection system is a standalone detection system, the transport module 110 is specifically used for carrying and transporting the droplet detection plane 130.

[0050] When the droplet detection system is integrated into an existing device as a functional component, the transport module 110 can be the transport equipment configured in the existing device, and the processing unit can also be integrated into the relevant control system of the existing device, so as to facilitate the unified operation of the existing device.

[0051] In some embodiments, the droplet detection system further includes a support frame 170 for adjusting the relative position of the droplet area 101 and the detection area 102.

[0052] After the nozzle 200 drops liquid, in order to facilitate the rapid transfer of the droplet to the detection area 102 for morphology detection by the transport module 110 and reduce the impact of evaporation on the accuracy of the detection results, the distance between the dripping area 101 and the detection area 102 needs to be small enough. In addition, since the droplet detection unit 120 and the nozzle 200 have certain physical dimensions in the actual space, the droplet area 101 and the detection area 102 cannot be infinitely close. Therefore, the relative installation position of the two can be determined by combining the actual size of the droplet detection unit 120 and the nozzle 200 to be tested, so as to adjust the distance between the droplet area 101 and the detection area 102. Alternatively, the structure of the support frame 170 can be set to allow the installation of droplet detection units 120 and / or nozzles 200 of different specifications to accommodate more detection conditions.

[0053] When installing the image acquisition unit 150, it is necessary to ensure that the images of the droplet detection system acquired by the image acquisition unit 150 are clear and unobstructed. In some embodiments, the image acquisition unit 150 is equipped with a coaxial illumination source to provide light for image acquisition and to perform video monitoring. The monitoring images acquired by the image acquisition unit 150 include: the process of the nozzle 200 dropping droplets onto the droplet detection plane 130; the distribution of droplets on the droplet detection plane 130; and the movement of the transport module 110 on the vibration damping platform 160. The processing unit can detect the droplet position coordinates, observe the droplet distribution, and the real-time position of the transport module 110 based on the images acquired by the image acquisition unit 150. When the droplet detection system needs to be integrated as a functional component into an existing device (such as an inkjet printer), if the image acquisition unit 150 of the existing device can acquire images of the droplet detection system that are clear and unobstructed, the image acquisition unit 150 of the existing device can be used directly without the need for an additional separate image acquisition unit 150.

[0054] Since the image acquisition unit 150 has a certain field of view and is installed at a designated position, it can obtain information such as the position of a single droplet and / or droplet array based on the image acquired by the image acquisition unit 150, and can determine the correspondence between the droplets in the acquired image and the nozzles / sprayers that generated the droplets; therefore, droplets from different nozzles / sprayers can be dropped onto the droplet detection plane 130. The processing unit determines the size, shape and other morphological information of the droplets at different positions on the droplet detection plane 130 based on the image acquired by the droplet detection unit 120, and determines the correspondence between the droplets at different positions on the droplet detection plane 130 and the nozzles / sprayers that generated the droplets based on the image acquired by the image acquisition unit 150, thereby enabling the consistency detection of multiple nozzles or sprayers to be completed at one time.

[0055] In some embodiments, the droplet detection system further includes a liquid supply unit for supplying liquid to the printhead 200 to be tested. To enable direct detection of the printhead 200, the droplet detection system is equipped with a separate liquid supply unit that supplies liquid to one or more printheads, or one or more nozzles within the printheads, thereby completing the detection. The liquid supply volume of the liquid supply unit is controlled by the processing unit according to the detection purpose. When the droplet detection system needs to be integrated as a functional component into an existing device (such as an inkjet printer), the existing device's liquid supply unit can be used directly, without the need for an additional separate liquid supply unit. The solution provided by the liquid supply unit is generally an aqueous solution, but can also be configured according to the object being detected, such as printing ink, immersion liquid, or chemical solution.

[0056] In some embodiments, a first direction and a second direction are defined on the droplet detection plane 130, and the first direction is perpendicular to the second direction. The transport module 110 can drive the droplet detection plane 130 to move along the first direction or the second direction.

[0057] When a plurality of nozzles of the nozzle 200 to be tested are arranged in a one-dimensional array along only the first direction or only the second direction, the transport module 110 can drive the droplet detection plane 130 to move only along the first direction or only along the second direction, thereby transporting the droplets dropped by the nozzle 200 to the droplet detection plane 130 to the detection area 102 for droplet detection.

[0058] When the nozzles of the detection nozzle 200 are arranged in a two-dimensional pattern, the droplets that fall from the nozzle 200 to be detected onto the droplet detection plane 130 are also arranged in a two-dimensional pattern. The transport module 110 can drive the droplet detection plane 130 to move along the first direction and / or the second direction, so that the droplet detection unit 120 can collect the morphological images of droplets at different positions on the droplet detection plane 130.

[0059] In some embodiments, the droplet detection system further includes a storage unit communicatively connected to the processing unit for storing droplet morphology detection results. The processing unit transmits the droplet morphology detection results acquired from the images collected by the droplet detection unit 120 to the storage unit for storage. The morphology detection results stored in the storage unit can provide data support for analysis and evaluation based on droplet morphology detection results, such as droplet properties and nozzle consistency assessment.

[0060] In some embodiments, the droplet detection system can be used for droplet detection in fields such as inkjet printing, drug titration, microfluidic device operation, and coating processes.

[0061] In some embodiments, the droplet detection system can be installed on a relevant production line, where the droplet area 101 is the area on the production line where droplets are generated. The processing unit can control the transport module 110 to transfer the droplets generated on the production line to the detection area 102 of the droplet detection unit 120 for morphology detection, thereby realizing online operation of droplet detection.

[0062] The present invention also provides a method for detecting droplets, comprising: S1, the relative positions of the calibrated droplet area 101, the detection area 102, the droplet detection plane 130, and the droplet detection unit 120; wherein, The dripping area 101 is used to drop 200 liquid droplets from the nozzle to be tested. The detection area 102 is equipped with a droplet detection unit 120 for acquiring droplet morphology images; The droplet detection plane 130 is used to hold the falling droplets and can move between the falling area 101 and the detection area 102; S2. In the dripping area 101, control the nozzle 200 to be tested to drip droplets onto the droplet detection plane 130; S3. Control the movement of the droplet detection plane 130 to move the droplet from the dropping area 101 to the detection area 102; S4. Control the droplet detection unit 120 to acquire droplet morphology images, process and output the droplet morphology images acquired by the droplet detection unit 120.

[0063] The droplet detection method provided by this invention first calibrates the relative positions of the droplet area 101, the detection area 102, the droplet detection plane 130, and the droplet detection unit 120. After the droplet is dropped, the droplet is moved from the droplet area 101 to the detection area 102 by moving the droplet detection plane 130. This eliminates the need to collect the sample from the droplet generation location and transport it to a separately set droplet detection instrument for droplet morphology detection, thus shortening the distance and time required for the droplet to be transported from the generation location to the detection location. Then, the morphology image of the droplet in the detection area 102 is acquired and processed to obtain the droplet's volume, diameter, and height. This enables rapid detection of tiny droplets, reduces the impact of droplet evaporation on the detection results, improves the real-time performance of the detection, and reduces the risk of detection result distortion.

[0064] In some embodiments, in S1, calibrating the relative positions of the droplet area 101, the detection area 102, the droplet detection plane 130, and the droplet detection unit 120 includes: calibrating the focal plane and focal point of the droplet detection unit 120; setting the detection area 102 on the focal plane of the field of view of the detection unit 120; and setting the droplet area 101, the detection area 102, and the droplet detection plane 130 on the same plane.

[0065] The focal plane and focus of the droplet detection unit 120 can be calibrated by moving the lens position along the optical axis of the lens, calculating the sharpness of a fixed target (such as a high-contrast checkerboard or USAF resolution test board) at different positions, finding the position corresponding to the maximum sharpness value as the optimal focal plane, and the center of the focal plane as the focus.

[0066] When the droplet falls onto the droplet detection plane 130, the focal plane of the droplet detection plane 130 and the droplet detection unit 120 are coplanar, so that the transport module 110 only needs to move on the horizontal plane. This not only shortens the moving distance of the transport module 110, but also reduces the possibility that the droplet morphology will be affected by the up-and-down movement of the transport module 110.

[0067] When the transport module 110 transports the droplet detection plane 130 to the detection area 102, the droplet detection plane 130 is positioned precisely within the field of view of the droplet detection unit 120 and on the focal plane. Thus, during the detection process, it is only necessary to control the movement of the transport module 110 to move the droplet to be detected on the droplet detection plane 130 to the focal point of the droplet detection unit 120, and the white light interference image of the droplet to be detected can be acquired through the droplet detection unit 120. There is no need to refocus the droplet detection unit 120 during each detection process, which saves detection time and improves detection efficiency.

[0068] In some embodiments, S1 further includes: calibrating the relative position of the image acquisition unit 150 by acquiring position images of the droplets on the droplet detection plane 130 through the image acquisition unit 150. In some embodiments, the image acquisition unit 150 can function as a video surveillance device.

[0069] The images acquired by the image acquisition unit 150 can not only determine the real-time position of the droplets, but also detect the position coordinates of the droplets and observe the distribution of the droplets based on the images acquired by the image acquisition unit 150.

[0070] When executing S3, the moving direction and moving distance of the droplet detection plane 130 can be controlled according to the image acquired by the image acquisition unit 150, so that the droplet on the droplet detection plane 130 can be moved from the droplet area 101 to the detection area 102.

[0071] Based on the images acquired by the image acquisition unit 150, the correspondence between the droplets on the droplet detection plane 130 and the nozzles that generated the droplets can also be determined. After determining the size, shape and other morphological information of the droplets at different positions on the droplet detection plane 130, the consistency detection of multiple nozzles can be completed by combining the images acquired by the image acquisition unit 150.

[0072] In some embodiments, the droplet detection method provided by the present invention is used to perform droplet detection on a nozzle 200 to be tested, which includes a plurality of nozzles. In S2, any nozzle of the nozzle 200 to be tested can be independently controlled to drip or stop dripping.

[0073] In some embodiments, during S2, when controlling the nozzle of the nozzle 200 to be detected to drop droplets onto the droplet detection plane 130, one or more nozzles of the nozzle 200 to be detected can be controlled to drop droplets at a time.

[0074] In S2, the number of nozzles for droplet detection can be set by combining the nozzle array arrangement of the nozzle 200, the droplet size, and the detection capability of the droplet detection unit 120. This ensures that the droplets can be detected by the droplet detection unit 120 as soon as they reach the detection area 102 from the droplet area 101. This avoids the droplets from queuing for detection after reaching the detection area 102, which could cause the later-detected droplets to evaporate and distort the detection results.

[0075] In S2, the nozzle that simultaneously dispenses the droplets can be such that after the droplets reach the detection area 102, they are simultaneously located within the focal plane of the field of view of the detection unit 120.

[0076] When the droplet detection unit 120 cannot detect all the droplets falling from all the nozzles of the nozzle 200 to be tested at once, the droplet detection method may further include: S5, controlling the droplet detection plane 130 to return to the dripping area 101, and repeating steps S2-S5 until all the nozzles of the nozzle 200 to be tested have completed droplet detection.

[0077] The droplet detection system and method provided by this invention are used to detect droplets in each nozzle of a multi-nozzle head, realizing rapid detection of large-area droplet arrays. By acquiring the morphological image of the droplets falling from each nozzle, the volume, diameter, and height of the droplets are obtained, enabling rapid detection of tiny droplets. This reduces the impact of droplet evaporation on the detection results, improves the real-time performance of the detection, reduces the risk of distortion of the detection results, and realizes the nozzle consistency detection and evaluation of multi-nozzle heads.

[0078] The droplet detection system provided by this invention can be integrated as a separate module into existing devices (such as inkjet printers). After the droplet system of the existing device drops the droplet, it can perform real-time online droplet morphology detection. Compared with the traditional droplet detection equipment that uses a separate droplet detection instrument, this improves the convenience of detection.

[0079] The present invention will be further described below through specific embodiments. However, the following embodiments are merely illustrative of the present invention, and the scope of the present invention is not limited thereto.

[0080] Example 1 This embodiment provides a droplet detection system. In this embodiment, the nozzle 200 to be detected can be a multi-nozzle nozzle, and several nozzles are arranged in a matrix on the nozzle 200 to be detected.

[0081] See Figure 1 The droplet detection system includes: a transport module 110, a droplet detection unit 120, a droplet detection plane 130, an image acquisition unit 150, a vibration damping platform 160, a support frame 170, a processing unit, and a storage unit.

[0082] The transport module 110 is mounted on the upper surface of the vibration damping platform 160. The vibration damping platform 160 can be an optical vibration damping platform, a marble base supported by an active vibration isolator, or other equipment capable of achieving vibration damping.

[0083] The transport module 110 includes a plate-bearing stage 111 and a movable base 112. The plate-bearing stage 111 is mounted on the movable base 112. The movable base 112 of the transport module 110 can be a six-axis micro-motion platform. Furthermore, the movable base 112 is equipped with a transmission mechanism, such as a ball screw, gear rack, worm gear, or other transmission mechanism capable of stepping.

[0084] The droplet detection plane 130 is disposed on the side of the stage 111 away from the movable base 112. The droplet detection plane 130 uses a low-reflectivity, high-transmittance substrate, such as a quartz substrate. A first direction and a second direction are defined on the droplet detection plane 130, and the first direction is perpendicular to the second direction. The first direction and the second direction can be transverse or longitudinal directions on the droplet detection plane 130.

[0085] The nozzle 200 to be tested, the droplet detection unit 120, and the image acquisition unit 150 are positioned above the droplet detection plane 130. The droplet detection unit 120 uses a white light detection head. The image acquisition unit 150 uses a wide field-of-view camera.

[0086] Specifically, the nozzle 200 to be tested, the droplet detection unit 120, and the image acquisition unit 150 are mounted above the droplet detection plane 130 via a support frame 170. On the support frame 170, the nozzle 200 is positioned close to the droplet detection unit 120. The support frame 170 includes two columns and a cantilever. The support frame 170 is connected to the vibration damping platform 160 via the columns, and both ends of the cantilever are connected to the columns. The nozzle 200, droplet detection unit 120, and image acquisition unit 150 are all mounted on the cantilever. A pitch adjustment mechanism is installed on the support frame 170 to adjust the pitch angles of the droplet detection unit 120, image acquisition unit 150, and nozzle 200. Adjusting the pitch angle of the nozzle 200 ensures that its nozzle is as perpendicular as possible to the droplet detection plane 130, reducing contact between the droplet and the nozzle during droplet fall and minimizing droplet deformation caused by contact with the nozzle. Adjust the pitch angle of the droplet detection unit 120 and the image acquisition unit 150 to ensure good image quality of the images acquired by the droplet detection unit 120 and the image acquisition unit 150.

[0087] The support frame 170 can also be configured as other devices with stable clamping function, which can ensure that the nozzle 200 to be tested, the droplet detection unit 120, and the image acquisition unit 150 are in stable position and function normally during the droplet detection process.

[0088] The area where the droplets fall from the nozzle 200 to be tested is the droplet area 101. The image capture area of ​​the droplet detection unit 120 is the detection area 102.

[0089] The mobile base 112, droplet detection unit 120, image acquisition unit 150, nozzle to be detected 200, and storage unit are all communicatively connected to the processing unit.

[0090] Preferably, the transport module 110 is capable of large-stroke motion in the horizontal plane and high-precision motion in three-dimensional space, such as six-axis micro-motion, and can be linked with the nozzle 200 to be tested under the control of the processing unit.

[0091] The processing unit controls the transport module 110 to move between the dripping area 101 and the detection area 102, and then controls the nozzle to be tested 200 to drip droplets onto the droplet detection plane 130 placed on the transport module 110.

[0092] The droplet detection system also includes a liquid supply unit for supplying liquid to the nozzle 200 to be tested. When the processing unit is communicatively connected to the nozzle 200, the processing unit can control the nozzles of the nozzle 200 to operate in a specific manner. Under the control of the processing unit, several nozzles of the nozzle 200 to be tested drip liquid one by one.

[0093] The droplet detection system performs droplet detection on each nozzle of the nozzle 200 to be tested. The processing unit sets the number of detection cycles based on the number of nozzles in the nozzle 200 to be tested. In each detection, the processing unit controls only one nozzle of the nozzle 200 to drop the droplet. After dropping, the processing unit controls the transport module 110 to move in a first or second direction, transferring the droplet from the dropping area 101 to the detection area 102. The droplet detection unit 120 acquires an image of the droplet, and processes the image to obtain the three-dimensional liquid morphology of the droplet, including parameters such as the volume, diameter, and height of the droplet, thereby completing the morphology detection of the droplet. After the morphology detection is completed, the processing unit controls the transport module 110 to return to the dropping area 101 to perform the next detection, until the number of detection cycles is reached.

[0094] The droplet detection system also includes a storage unit that is communicatively connected to the processing unit to store the droplet morphology detection results. The detection results for each droplet morphology detection are stored in the storage unit. The droplet morphology detection results stored in the storage unit can be used for subsequent analysis (such as nozzle consistency evaluation).

[0095] After the droplet detection unit 120, image acquisition unit 150 and nozzle 200 to be tested are installed and adjusted, and the number of detection cycles is set, the processing unit controls the nozzles of the nozzle 200 to be tested to drip liquid one by one.

[0096] After the processing unit controls the nozzle to droplet onto the droplet detection plane 130, the processing unit controls the transport module 110 to transfer the droplet from the droplet area 101 to the detection area 102 where the droplet detection unit 120 is located. Then, the processing unit uses the droplet detection unit 120 to perform morphological detection on the droplet and stores the morphological detection results in the storage unit. The processing unit sets the number of detection cycles according to the number of nozzles in the nozzle 200 to be tested, which can realize automated detection and perform droplet detection on each nozzle in the nozzle 200 to be tested.

[0097] After performing droplet detection on the previous nozzle, the processing unit controls the transport module 110 to return from the detection area 102 of the droplet detection unit 120 to the dripping area 101 of the nozzle to be tested 200 to perform droplet detection on the next nozzle.

[0098] After installing and adjusting the droplet detection unit 120, image acquisition unit 150, and nozzle 200 to be tested, and setting the number of testing cycles, the droplet detection system can automatically detect each nozzle in the nozzle 200 to be tested, thus improving detection efficiency.

[0099] Example 2 See Figure 2 This embodiment provides a droplet detection method, including the following steps: S1, relative positions of calibrated droplet area 101, detection area 102, droplet detection plane 130, droplet detection unit 120, and image acquisition unit 150; S2. In the dripping area 101, control the nozzle of the nozzle 200 to be tested to drip droplets onto the droplet detection plane 130; S3. Control the movement of the droplet detection plane 130 to move the droplet from the dropping area 101 to the detection area 102; S4. Control the droplet detection unit 120 to acquire droplet morphology images, process and output the droplet morphology images acquired by the droplet detection unit 120; S5. Control the droplet detection plane 130 to return to the droplet area 101; Repeat steps S2-S5 until all nozzles of the nozzle 200 to be tested have completed droplet detection.

[0100] The dripping area 101 is the area where the droplets from the nozzle 200 to be tested drip.

[0101] The detection area 102 is the area where the droplet detection unit 120 collects the morphological image of the droplet.

[0102] The droplet detection unit 120 uses a white light detection head.

[0103] The droplet detection plane 130 is a semiconductor substrate with optical properties that have a reflectivity higher than transmittance.

[0104] The image acquisition unit 150 can be a wide field-of-view camera.

[0105] The droplet detection plane 130 is driven by the transport module 110.

[0106] In S2, the method for controlling the dripping of the nozzle 200 to be tested includes: setting layout information and controlling the working mode of the nozzles in the nozzle 200 to be tested according to the layout information. The layout information includes: the arrangement of target droplets on the droplet detection plane 130. The working mode of the nozzle 200 to be tested includes the number of nozzles working during the dripping process, the dripping sequence of each nozzle, and the dripping time.

[0107] During the S1 calibration process of the relative positions of the dripping area 101, detection area 102, droplet detection plane 130, droplet detection unit 120, and image acquisition unit 150, the image acquired by the image acquisition unit 150 maps the detection area 102 of the droplet detection unit 120 and the dripping area 101 of the nozzle to be tested 200 to the XY translation coordinate system of the transport module 110. This enables the processing unit to control the transport module 110 to move accurately between the dripping area 101 of the nozzle to be tested 200 and the detection area 102 of the droplet detection unit 120, and ensures that the droplets dripping from each nozzle do not overlap.

[0108] In S2, when controlling the nozzle of the nozzle to be tested 200 to drop droplets onto the droplet detection plane 130, one or more nozzles of the nozzle to be tested 200 can be controlled to drop droplets at a time.

[0109] Since the detection capacity of the drop detection unit 120 is limited and it cannot detect droplets falling from all nozzles of the nozzle 200 to be tested at the same time, in order to make the detection results as accurate as possible, in S2, only a portion of the nozzles (one or more nozzles) of the nozzle 200 to be tested are controlled to droplet at a time. This allows the droplets to be detected by the drop detection unit 120 as soon as they reach the detection area 102 from the droplet area 101. This avoids the detection results from being distorted due to the evaporation of droplets that are detected later in the queue after multiple droplets arrive at the detection area 102 at the same time.

[0110] The droplet detection method provided in this embodiment can be performed using the droplet detection system described in Embodiment 1.

[0111] After S1 is completed, the cycle detection of S2-S5 can be completed under the control of the processing unit, thereby realizing the automated detection of each nozzle in the 200 nozzles to be tested.

[0112] In S2, the processing unit controls the nozzle 200 to be detected to drop droplets onto the droplet detection plane 130 according to the preset layout information.

[0113] In S3, the processing unit controls the transport module 110 to move, moving the droplet detection plane 130 from the droplet area 101 to the detection area 102; In S4, the processing unit controls the droplet detection unit 120 to acquire the morphological image of the droplet on the droplet detection plane 130, processes the morphological image of the droplet acquired by the droplet detection unit 120 to obtain the three-dimensional morphological information of the droplet, such as volume, diameter, and height, and transmits the three-dimensional morphological information of the droplet to the storage unit for storage.

[0114] In step S5, the processing unit controls the movement of the transport module 110, causing the droplet detection plane 130 to return to the droplet area 101, and repeats steps S2-S5 until all nozzles of the nozzle 200 to be tested have completed droplet detection.

[0115] This embodiment enables automated detection of each nozzle in the 200 nozzles to be tested, improving both real-time detection and detection efficiency.

[0116] The morphology detection results stored in the storage unit can provide data support for nozzle consistency evaluation.

[0117] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A droplet detection system, characterized in that, include: The dripping area (101) is used for the nozzle (200) to drop liquid droplets; The detection area (102) is provided with a droplet detection unit (120) for acquiring the morphological image of the droplet; A droplet detection plane (130) is used to hold the falling droplets; The transport module (110) is used to move the droplet detection plane (130) between the droplet area (101) and the detection area (102); The processing unit is used to process the morphological image of the droplet and to control the moving direction and distance of the carrier module (110).

2. The droplet detection system according to claim 1, characterized in that, The transport module (110) includes a plate holder (111) and a movable base (112); the plate holder (111) is used to place the droplet detection plane (130), and the movable base (112) is used to move the plate holder (111).

3. The droplet detection system according to claim 1, characterized in that, It also includes a vibration damping platform (160) for providing vibration damping for the droplet detection system.

4. The droplet detection system according to claim 1, characterized in that, The droplet detection plane (130) has optical properties where the reflectivity is higher than the transmittance.

5. The droplet detection system according to claim 1, characterized in that, The droplet detection unit (120) uses a white light detection head, and the processing unit uses an image processing algorithm to process the white light interference image of the droplet to obtain the three-dimensional morphology information of the droplet.

6. The droplet detection system according to claim 1, characterized in that, It also includes an image acquisition unit (150) for acquiring images of the position of the droplets on the droplet detection plane (130); The processing unit is also used to process the droplet position image acquired by the image acquisition unit (150).

7. The droplet detection system according to claim 6, wherein the nozzle to be detected (200) comprises a plurality of nozzles; The processing unit can independently control any nozzle of the nozzle to be tested (200).

8. A method for detecting droplets, characterized in that, include: S1, the relative positions of the calibrated droplet area (101), the detection area (102), the droplet detection plane (130), and the droplet detection unit (120); wherein, The dripping area (101) is used for the nozzle (200) to drop liquid droplets; The detection area (102) is provided with a droplet detection unit (120) for acquiring the morphological image of the droplet; The droplet detection plane (130) is used to carry the falling droplets and can move between the falling area (101) and the detection area (102); S2. In the dripping area (101), control the nozzle to be tested (200) to drip droplets onto the droplet detection plane (130); S3. Control the droplet detection plane (130) to move, and move the droplet from the droplet area (101) to the detection area (102). S4. Control the droplet detection unit (120) to acquire droplet morphology images, and process and output the droplet morphology images acquired by the droplet detection unit (120).

9. The droplet detection method according to claim 8, characterized in that, S1 further includes: acquiring the position image of the droplet on the droplet detection plane (130) through the image acquisition unit (150) to calibrate the relative position of the image acquisition unit (150).

10. The droplet detection method according to claim 8, characterized in that, In S1, the calibration of the relative position of the detection area (102) and the droplet detection unit (120) also includes calibrating the focal plane and focal point of the droplet detection unit (120).

Images