Preparation method of night light speckle applied to non-illumination condition

Abstract

The application discloses a night light speckle preparation method applied to a non-illumination condition, which comprises the following steps: designing a digital speckle pattern, selecting the diameter size of the digital speckle according to the distance of a to-be-detected target, and generating a corresponding digital speckle pattern according to the diameter size of the digital speckle; preparing a solution, uniformly mixing ink and a luminophore material in proportion, and then introducing the mixed solution into a needle cylinder for standby, wherein the particle diameter of the luminophore material is 2-8 microns; loading an ink cartridge, injecting the mixed solution in the needle cylinder into the ink cartridge through an ink injection hole, discharging the air in the ink cartridge by using a suction press, and then plugging the ink injection hole by using a steel ball; preparing a sample, processing the to-be-tested piece into a predetermined size, and cleaning and drying the surface of the to-be-tested piece; and spraying speckles, printing the solution in the ink cartridge on the to-be-tested piece according to the digital speckle pattern by using a code spraying machine. The application has the advantages of simple operation, easy implementation, low manufacturing cost and the like.

Description

Technical Field

[0001] This invention relates to the technical field of DIC measurement, and in particular to a method for preparing luminous speckle patterns under no-light conditions. Background Technology

[0002] Digital image correlation (DIC), as an advanced image-based optical technique, can measure the full-field morphology, displacement, and deformation of an object's surface, ranging from microscopic to macroscopic. It has been widely applied in materials science, biomechanics, and mechanical manufacturing, and is widely recognized as a popular tool for experimental mechanical measurements. It offers simple measurement methods and high accuracy. Speckle, as the information carrier in DIC measurements, requires high contrast, randomized speckle size and arrangement, a high-quality speckle pattern on the surface being measured, and the ability to deform along with the structure.

[0003] Currently, the DIC method, also known as fluorescent DIC, commonly uses fluorescent particles to create speckle patterns for shape and deformation measurements. Studies have shown that compared to methods using black and white matte paint to create speckle patterns, this method eliminates specular reflections, allows observation of object surface structures, and produces high-contrast speckle patterns, resulting in higher measurement accuracy. It has been widely used in high-temperature applications, composite materials, and battery electrodes. However, this method requires active ultraviolet light illumination to excite fluorescence on the object's surface for imaging, making it unsuitable for long-distance or real-time measurements at night. Summary of the Invention

[0004] This invention provides a method for preparing luminous speckle patterns under no-light conditions, mainly to solve the problem of real-time nighttime light compensation required for nighttime measurements.

[0005] The specific technical solution is as follows: To solve the above-mentioned technical problems, the present invention is implemented as follows: In a first aspect, a method for preparing luminous speckle patterns applicable under conditions of no light is provided, comprising the following steps: Designing digital speckle patterns: First, select the diameter of the digital speckle based on the distance to the target to be measured, and then generate the corresponding digital speckle pattern based on the diameter of the speckle. Solution preparation: Mix the ink and the luminescent material in a certain proportion until homogeneous, and then introduce the mixed solution into a syringe for later use. The particle diameter of the luminescent material is 2-8 μm. Loading ink cartridges: Inject the mixed solution from the syringe into the ink cartridge through the ink injection hole, use a pump to remove the air from the ink cartridge, and then use a steel ball to plug the ink injection hole; Sample preparation: The test piece is processed into a predetermined size, and its surface is cleaned and dried; Spraying speckle pattern: The designed digital speckle pattern is transferred to the inkjet printer via a mobile storage device. The inkjet printer then prints the solution in the ink cartridge onto the test piece according to the digital speckle pattern.

[0006] In one embodiment, during the step of designing the digital speckle pattern, the diameter of the selected digital speckle is designed to ensure that the size of a single speckle in the image captured by the image acquisition system is controlled within 3-5 pixels.

[0007] In one embodiment, in the step of designing the digital speckle pattern: the image scale of the target to be measured is Xpixel·mm. -1 To obtain a speckle pattern in Y pixels, the diameter D of the chosen digital speckle is calculated using the formula (X pixels) / (Y pixels·mm). -1 Then, based on the diameter of the speckle, the corresponding digital speckle pattern is generated in Glare.

[0008] In one embodiment, in the solution preparation step, the ink and the luminescent material are mixed at a weight ratio of 2:1 and introduced into a test tube. The mixture is stirred for 3-5 minutes using an ultrasonic mixer, and then the mixed solution is introduced into a syringe for later use.

[0009] In one embodiment, the surface cleaning and drying process of the test specimen involves first cleaning the surface of the test specimen with acetone, then wiping it clean with cotton balls, and finally drying it.

[0010] Secondly, a method for preparing luminous speckle patterns applicable under no-light conditions is provided, comprising the following steps: Designing digital speckle patterns: First, select the diameter of the digital speckle based on the distance to the target to be measured, and then generate the corresponding digital speckle pattern based on the diameter of the speckle. Solution preparation: Mix the ink and the luminescent material in a certain proportion until homogeneous, and then introduce the mixed solution into a syringe for later use. The particle diameter of the luminescent material is greater than 8 μm. Fabrication of the luminescent substrate: The test piece is processed into a predetermined size, and its surface is cleaned and dried. Then, the mixed solution is evenly rolled onto the surface of the test piece. Spraying speckle pattern: The designed digital speckle pattern is transferred to the inkjet printer via a mobile storage device, and the inkjet printer prints ink onto the test piece according to the digital speckle pattern.

[0011] In one embodiment, during the step of designing the digital speckle pattern, the diameter of the selected digital speckle is designed to ensure that the size of a single speckle in the image captured by the image acquisition system is controlled within 3-5 pixels.

[0012] In one embodiment, in the step of designing the digital speckle pattern: the image scale of the target to be measured is Xpixel·mm. -1 To obtain a speckle pattern in Y pixels, the diameter D of the chosen digital speckle is calculated using the formula (X pixels) / (Y pixels·mm). -1 Then, based on the diameter of the speckle, the corresponding digital speckle pattern is generated in Glare.

[0013] In one embodiment, in the solution preparation step, the ink and the luminescent material are mixed at a weight ratio of 2:1 and introduced into a test tube. The mixture is stirred for 3-5 minutes using an ultrasonic mixer, and then the mixed solution is introduced into a syringe for later use.

[0014] In one embodiment, the surface cleaning and drying process of the test specimen involves first cleaning the surface of the test specimen with acetone, then wiping it clean with cotton balls, and finally drying it.

[0015] In this embodiment of the invention, an inkjet solution is prepared by mixing ink with a luminescent material. The inkjet printer then prints the inkjet solution onto the test piece according to a designed digital speckle pattern. Thus, the printing process requires no illumination and consumes no energy. The inkjet solution prepared by this invention inherits the advantages of fluorescent speckle, eliminating specular reflection and producing a high-contrast speckle pattern. The measurement accuracy is higher than that of the classic DIC method. It avoids the problem of "heat waves" generated between the imaging system and the speckle due to prolonged exposure to active light sources, which can lead to increased measurement errors. This invention has the advantages of simple operation, ease of implementation, and low manufacturing cost. Attached Figure Description

[0016] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this invention, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention. In the drawings: Figure 1 This is a flowchart illustrating the steps of the method for preparing luminous speckle patterns under no-light conditions in Embodiment 1 of the present invention. Figure 2 This is a schematic diagram of the design speckle pattern process in Embodiment 1 of the present invention; Figure 3 This is a schematic diagram of the process of preparing luminous speckle with an inkjet printer according to Embodiment 1 of the present invention; Figure 4 This is a flowchart illustrating the steps of the method for preparing luminous speckle patterns under no-light conditions in Embodiment 2 of the present invention. Figure 5 This is a schematic diagram of the process of preparing luminescent speckle patterns using a luminescent material as a substrate in Embodiment 2 of the present invention; Figure 6 This is a speckle pattern of nighttime light in a no-light-source scene according to Embodiment 2 of the present invention. Detailed Implementation

[0017] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] Long-afterglow materials are luminescent materials that store excitation energy and release it as light through thermal, optical, or mechanical stimulation after the excitation source stops radiating. They are also known as energy-storage luminescent materials. Compared to fluorescent materials that rely on real-time excitation, long-afterglow materials can last for seconds, hours, or even days. A novel green long-afterglow strontium aluminate phosphor (SrAl₂O₄:Eu²⁺, Dy³⁺) was first reported in 1996, with an afterglow duration of up to 20 hours. Since then, due to their excellent luminescence intensity, high afterglow efficiency, and long afterglow time, long-afterglow materials have been widely used in emergency signs, watch faces, luminescent coatings, and in vivo imaging.

[0019] The speckle patterning method using fluorescent particles to create speckle patterns for shape and deformation measurements, also known as fluorescent DIC, has been shown to eliminate specular reflections, allow observation of object surface structures, and produce high-contrast speckle patterns compared to traditional methods using matte black and white paint, resulting in higher measurement accuracy. It has been widely applied in high-temperature applications, composite materials, and battery electrodes. However, unlike long-persistent light materials, this method requires active ultraviolet light illumination to excite fluorescence on the object's surface, enabling imaging in the imaging system. In long-distance and real-time nighttime measurement scenarios, the advantages of speckle patterns prepared using long-persistent light materials become particularly apparent.

[0020] The present invention provides a method for preparing luminescent speckle patterns under no-light conditions. This method uses long-afterglow materials to create speckles, providing a nighttime DIC measurement method that requires no light and consumes no energy. From one perspective, it represents a further extension of fluorescence DIC measurement, inheriting its advantages while addressing scenarios where fluorescence DIC measurement is difficult. The present invention provides two main preparation methods for luminescent materials of different particle sizes, as shown in Examples 1 and 2. Wherein: Please see Figures 1 to 3 , Figure 1 This is a flowchart illustrating the steps of the method for preparing luminous speckle patterns under no-light conditions according to Embodiment 1 of the present invention. Figure 2This is a schematic diagram of the design process of speckle pattern in Embodiment 1 of the present invention. Figure 3 This is a schematic diagram illustrating the process of preparing luminous speckle patterns using an inkjet printer according to Embodiment 1 of the present invention; as shown in the figure, the method for preparing luminous speckle patterns under no-light conditions in this embodiment includes the following steps S1 to S5. Wherein: Step S1, Design Digital Speckle Pattern: First, select the diameter of the digital speckle based on the distance to the target, then generate the corresponding digital speckle pattern based on the speckle diameter. The selected digital speckle diameter must ensure that the size of a single speckle in the image acquired by the image acquisition system is controlled within 3-5 pixels. The image scale of the target is Xpixel·mm. -1 To obtain a speckle pattern in Y pixels, the diameter D of the chosen digital speckle is calculated using the formula (X pixels) / (Y pixels·mm). -1 Then, based on the diameter of the speckle, a corresponding digital speckle pattern is generated in Glare. For example, the image scale is 20 pixels per millimeter. -1 To obtain a 5-pixel speckle pattern, the diameter of the digital speckle is (5 pixels) / (20 pixels·mm-1) = 0.25 mm. Based on this speckle size, the desired speckle pattern can be easily output in Glare.

[0021] Step S2, Solution Preparation: Mix the ink and luminescent material evenly according to the specified ratio, then pour the mixed solution into a syringe for later use. The particle diameter of the luminescent material is 2-8 μm. For luminescent materials with a particle diameter of 2-8 μm, a self-prepared mixing solution is used to prepare the ink cartridge solution, mainly because the ink cartridge is relatively precise, and the nozzle outlet diameter cannot exceed 8 μm, otherwise it will cause nozzle blockage and render the ink cartridge unusable. Mix the ink and luminescent material at a weight ratio of 2:1, pour the mixture into a test tube, stir it using an ultrasonic mixer for 3-5 minutes, and then pour the mixed solution into a syringe for later use.

[0022] Step S3, Loading the Ink Cartridge: Inject the mixed solution from the syringe into the ink cartridge through the ink injection port. Use a pump to purge the air from the cartridge, then plug the ink injection port with a steel ball. Inject the mixed solution from the syringe into the cartridge. Since the selected cartridge can only hold 42-44ml of solution, we inject 42ml here to prevent overflow. Then use the pump to purge the air from the cartridge; stop pumping as soon as the solution overflows, and simultaneously plug the injection port with a steel ball.

[0023] Step S4, Sample Preparation: The test piece is processed to a predetermined size, and its surface is cleaned and dried. For cleaning and drying the test piece, acetone is first used to clean the surface, followed by wiping with a cotton ball and then drying.

[0024] Step S5, Spraying the speckle pattern: The designed digital speckle pattern is transferred to the inkjet printer via a mobile storage device. The inkjet printer then prints the ink solution from the cartridge onto the test piece according to the digital speckle pattern. The speckle preparation is completed by transferring the designed digital speckle pattern from step S1 to the inkjet printer via a mobile storage device and printing according to the image.

[0025] This embodiment of the method for preparing luminescent speckle patterns under no-light conditions involves mixing ink with a luminescent material to prepare an inkjet solution. This eliminates the need for illumination and energy consumption during subsequent printing. The inkjet solution prepared in this embodiment inherits the advantages of fluorescent speckle patterns, eliminating specular reflection and producing high-contrast speckle patterns. The measurement accuracy is higher than that of the classic DIC method. It avoids the problem of "heat waves" generated between the imaging system and the speckle pattern due to prolonged exposure to an active light source, which can lead to increased measurement errors. This preparation method is simple to operate, easy to implement, and has low manufacturing costs.

[0026] Please see Figures 4 to 6 , Figure 4 This is a flowchart illustrating the steps of the method for preparing luminous speckle patterns under no-light conditions in Embodiment 2 of the present invention. Figure 5 This is a schematic diagram illustrating the process of preparing luminescent speckle patterns using a luminescent material as a substrate in Embodiment 2 of the present invention. Figure 6 This is a luminous speckle pattern in a light-free environment according to Embodiment 2 of the present invention. As shown in the figure, the method for preparing luminous speckle patterns under light-free conditions in this embodiment includes the following steps S1 to S4. Step S1 in this embodiment is the same as step S1 in Embodiment 1 above. The difference between step S2 in this embodiment and step S2 in Embodiment 1 above lies in the selection of the particle diameter size of the luminescent material. In this embodiment, the particle diameter of the luminescent material is greater than 8 μm.

[0027] Step S3, Preparing the luminescent substrate: The test specimen is processed to a predetermined size, and its surface is cleaned and dried. Then, the mixed solution is evenly rolled onto the surface of the test specimen. The test specimen material is processed to a predetermined size, and its surface is first cleaned with acetone, then wiped dry with cotton balls. After drying, the solution is evenly rolled onto the surface of the specimen using a brush or roller. It is important to note that the long afterglow luminescence time is related to the particle size and the spraying area; therefore, multiple sprayings are necessary. Too many sprays at once can cause the substrate to crack and generate bubbles; while too few sprays will result in a short luminescence duration, making it difficult to complete the DIC calculation process for the luminescence intensity per unit area.

[0028] Step S4, Spraying the speckle pattern: The designed digital speckle pattern is transferred to the inkjet printer via a mobile storage device. The inkjet printer prints ink onto the test piece according to the digital speckle pattern. The speckle preparation is completed by transferring the designed digital speckle pattern from step S1 to the inkjet printer via a mobile storage device and printing according to the image.

[0029] The method for preparing luminescent speckle patterns under no-light conditions in this embodiment differs from the method for preparing luminescent speckle patterns under no-light conditions in Example 1 above in that the particle diameter of the luminescent material used in this embodiment is greater than 8 μm, and the mixed solution of ink and luminescent material is applied to the test piece as a luminescent substrate. In addition, the inkjet printer in this embodiment can use an ink cartridge loaded with ordinary black ink.

[0030] In summary, this invention provides a method for preparing luminescent speckle patterns under no-light conditions. An inkjet solution is prepared by mixing ink with a luminescent material. An inkjet printer then prints the inkjet solution onto the test piece according to a designed digital speckle pattern. Thus, the printing process requires no light and consumes no energy. The inkjet solution prepared by this invention inherits the advantages of fluorescent speckle patterns, eliminating specular reflection and producing high-contrast speckle patterns. The measurement accuracy is higher than that of the classic DIC method. It avoids the problem of "heat waves" generated between the imaging system and the speckle pattern due to prolonged exposure to active light sources, which can lead to increased measurement errors. This invention has the advantages of simple operation, ease of implementation, and low manufacturing cost.

[0031] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0032] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of the present invention.

Claims

1. A method for preparing luminous speckle patterns under no-light conditions, characterized in that, Includes the following steps: Designing a digital speckle pattern: First, select the diameter of the digital speckle based on the distance to the target. Then, generate the corresponding digital speckle pattern based on the speckle diameter. The selected digital speckle diameter must ensure that the size of a single speckle in the image acquired by the image acquisition system is controlled within 3-5 pixels. The image scale of the target is X pixels·mm. -1 To obtain Ypixel speckle, the selected digital speckle diameter D is calculated using the formula Y / X mm. Based on the speckle diameter, the corresponding digital speckle pattern is generated in Glare. Solution preparation: Mix the ink and long afterglow luminescent material evenly in a certain proportion, and then pour the mixed solution into a syringe for later use. The particle diameter of the long afterglow luminescent material is 2-8 μm. The ink and the long afterglow luminescent material are mixed in a weight ratio of 2:1 and poured into a test tube. Stir with an ultrasonic mixer for 3-5 minutes, and then pour the mixed solution into a syringe for later use. Loading ink cartridges: Inject the mixed solution from the syringe into the ink cartridge through the ink injection hole, use a pump to remove the air from the ink cartridge, and then use a steel ball to plug the ink injection hole; Sample preparation: The test piece is processed into a predetermined size, and its surface is cleaned and dried. In the step of cleaning and drying the surface of the test piece, the surface of the test piece is first cleaned with acetone, then wiped clean with cotton balls, and then dried. Spraying speckle pattern: The designed digital speckle pattern is transferred to the inkjet printer via a mobile storage device, and the inkjet printer prints the solution in the ink cartridge onto the test piece according to the digital speckle pattern.

2. A method for preparing luminous speckle patterns under no-light conditions, characterized in that, Includes the following steps: Designing a digital speckle pattern: First, select the diameter of the digital speckle based on the distance to the target. Then, generate the corresponding digital speckle pattern based on the speckle diameter. The selected digital speckle diameter should ensure that the size of a single speckle in the image acquired by the image acquisition system is controlled within 3-5 pixels. The image scale of the target is X pixels·mm. -1 To obtain Ypixel speckle, the selected digital speckle diameter D is calculated using the formula Y / X mm. Based on the speckle diameter, the corresponding digital speckle pattern is generated in Glare. Solution preparation: Mix the ink and long afterglow luminescent material evenly in a certain proportion, and then pour the mixed solution into a syringe for later use. The particle diameter of the long afterglow luminescent material is greater than 8μm. The ink and the long afterglow luminescent material are mixed in a weight ratio of 2:1 and poured into a test tube. Stir with an ultrasonic mixer for 3-5 minutes, and then pour the mixed solution into a syringe for later use. Fabrication of the luminescent substrate: The test piece is processed into a predetermined size, and its surface is cleaned and dried. Then, the mixed solution is uniformly rolled onto the surface of the test piece. In the step of cleaning and drying the surface of the test piece, acetone is first used to clean the surface of the test piece, then cotton balls are used to wipe it clean, and then it is dried. Spraying speckle pattern: The designed digital speckle pattern is transferred to the inkjet printer via a mobile storage device. The inkjet printer prints black ink onto the surface of the test piece on which the luminescent substrate is formed, according to the digital speckle pattern.

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