Light-emitting device, visual identification device and printing equipment

Abstract

The utility model belongs to the technical field of machine vision, solves the defects of complicated operation and poor adaptability in the prior art, and provides a light-emitting device, a visual identification device and printing equipment. The light source is fixed on the bracket and provides wavelength-adjustable light for shooting of the camera; and the reflecting plate is arranged on the bracket and reflects the wavelength-adjustable light to a shot object which is positioned below the light source and is shot by the camera. The light-emitting device, the visual identification device and the printing equipment provided by the utility model have the advantages of simple operation and good adaptability.

Description

Technical Field

[0001] This utility model relates to the field of machine vision technology, and in particular to light-emitting devices, visual recognition devices, and printing equipment. Background Technology

[0002] Inkjet printing technology refers to the technology of spraying ink onto a printing medium through nozzles on a printhead to obtain images or text. For inkjet printing equipment that uses inkjet printing technology, some of them are equipped with a visual recognition device mainly used to identify the position information of the printed object.

[0003] For existing inkjet printing equipment equipped with a visual recognition device, the printed object is placed on a belt and moves with the belt. The light-emitting device of the visual recognition device illuminates the printed object with a light source, and the camera takes a picture of the printed object to collect a digital image of the printed object. The position of the printed object is then determined by analyzing the image.

[0004] Inkjet printing equipment often needs to be compatible with a wide variety of different printed materials, which have different colors, materials, and surface treatment processes. However, existing light-emitting devices use fixed light sources with a fixed wavelength, which often requires adjusting the hardware structure, algorithms, or other parameters to ensure the recognition effect of the digital images captured by the camera when printing different printed materials. This results in cumbersome operation and poor adaptability.

[0005] Therefore, there is an urgent need to provide a light-emitting device, a visual recognition device, and a printing equipment that are easy to operate and adaptable. Utility Model Content

[0006] To address the shortcomings of the existing technology, such as cumbersome operation and poor adaptability, this utility model provides a light-emitting device, comprising: a bracket; a light source fixed on the bracket and providing wavelength-adjustable light for camera shooting; and a reflector disposed on the bracket and reflecting wavelength-adjustable light onto the subject being photographed by the camera, located below the light source.

[0007] Furthermore, the support includes a pair of frame bodies, and the reflectors are configured as a pair that are connected to one of the frame bodies and spaced apart from each other. The space between the pair of reflectors forms a shooting hole through which the camera takes pictures.

[0008] Furthermore, the frame body and the shooting hole both extend along the first direction. A light source is fixed at the lower end of the inner side of each pair of frame bodies facing each other. A pair of reflectors are respectively connected to the upper end of the inner side, forming a reflective cavity between the inner sides of the pair of frame bodies. The side of the reflector facing the reflective cavity is set as a reflective arc surface.

[0009] Furthermore, a scattering structure layer is provided on the reflective arc surface to scatter the light incident upon it.

[0010] Furthermore, the scattering structure layer is configured as a nano-scattering coating, a micro / nanopillar array, or a transparent porous structure. The micro / nanopillar array is prepared using a nanoimprinting process, and the transparent porous structure is made of aluminosilicate material or transparent polymer material.

[0011] Furthermore, the light source includes a light panel, multiple LED beads, and a light-transmitting dust cover. The dust cover is placed on the light panel. The multiple LED beads include three types of LED beads that emit R, G, and B light respectively. The three types of LED beads are arranged alternately on the light panel. The working wavelength, working color temperature, number of on / off states, and / or color spots formed by each LED bead can be adjusted according to the different objects being photographed.

[0012] Furthermore, the reflective arc surface is set as a parabola, the length of the reflector extending along the first direction is set as L, the distance between the LED and the center line of the shooting hole is set as D, the vertical distance between the LED and the reflector is set as H, the width of the shooting hole between the two reflectors is set as W, and the divergence angle after reflection by the parabola is set as θ. In order for the light emitted by the LED to be uniformly reflected onto the subject by the reflective arc surface while not being directly emitted onto the camera, the following conditions must be met: θ≥θ min ,in, Δ = Df, where f is the focal length of the parabola. And W≤2D sinθ min .

[0013] Furthermore, the frame body is made of metal, and heat dissipation parts are provided on the outer surfaces of a pair of frame bodies facing away from each other. The heat dissipation parts are heat dissipation fins and / or heat dissipation grooves, and cooling fans are provided on the heat dissipation parts.

[0014] To achieve another objective of this utility model, a visual recognition device is provided, including a camera and any of the above-mentioned light-emitting devices, wherein the camera captures an object illuminated by wavelength-tunable light reflected by a reflector.

[0015] To achieve another objective of this utility model, a printing device is provided, including a printhead, a belt, and any of the above-mentioned visual recognition devices, characterized in that the object to be photographed is a printed object conveyed by the belt to the area below the printhead, and the nozzle of the printhead sprays ink onto the printed object whose position is determined according to the camera's image capture.

[0016] The beneficial effects of this utility model are as follows:

[0017] The light-emitting device, visual recognition device, and printing equipment provided by this utility model employ a light source capable of emitting wavelength-tunable light. When the photographed object is used as the printed object and its surface has various colors and complex shapes, based on the selected feature area on the surface of the printed object, the imaging effect of the feature area can be artificially enhanced and noise pollution suppressed by adjusting the output of light of different wavelengths from the light source. This allows for compatibility with different photographed objects, such as those with a wide variety of printable materials, and adaptability to different colors, materials, and surface treatment processes of different photographed objects. Furthermore, when different photographed objects are used as printed objects, there is no need to adjust the hardware structure, algorithm, or other parameters to ensure the recognition effect of the digital image captured by the camera. Therefore, it achieves the advantages of simple operation and good adaptability. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments of this utility model will be briefly introduced below. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort, and these are all within the protection scope of this utility model.

[0019] Figure 1 A schematic diagram of the light-emitting device provided in an embodiment of the present utility model from a downward-looking axisymmetric perspective;

[0020] Figure 2 Another structural schematic diagram of the light-emitting device provided in this embodiment of the utility model, viewed from an upward axisymmetrical perspective, omitting the dust cover of the light source;

[0021] Figure 3 A schematic diagram of the light-emitting device provided in this embodiment of the present invention from a top-down axial side view, omitting the dust cover of the light source;

[0022] Figure 4 Another structural schematic diagram of the light-emitting device provided in this embodiment of the utility model, viewed from a top-down axisymmetrical perspective, omitting the dust cover of the light source;

[0023] Figure 5 A schematic diagram of the structure of the light source of the light-emitting device provided in the embodiment of this utility model with the dust cover in a separated state;

[0024] Explanation of reference numerals in the attached figures:

[0025] 1-Bracket; 11-Bracket body; 2-Light source; 21-Light board; 22-LED beads; 23-Dust cover; 3-Reflector; 4-Shooting hole; 5-Heat dissipation unit; 6-Cooling fan; 6-Cooling fan. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. In the description of this utility model, it should be understood that the terms "center," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, 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. Without further limitation, an element limited by the phrase "comprising..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element. Unless otherwise specified, embodiments of the present invention and the various features thereof can be combined with each other, all within the protection scope of the present invention.

[0027] refer to Figures 1 to 4As an objective of this invention, a light-emitting device is provided, comprising a bracket 1, a light source 2, and a reflector 3. The light source 2 is fixed to the bracket 1 and provides wavelength-tunable light for camera shooting. The light source 2 is mounted on the bracket 1 and reflects wavelength-tunable light onto the subject being photographed by the camera, located below the light source 2. The camera can be positioned relative to the light source 2 and the reflector 3 according to the actual shooting needs. Furthermore, it should be noted that the reflector 3 can be mounted on the bracket 1 as an independent component connected to the bracket 1, or it can be integrally formed with the bracket 1 as part of the bracket 1. In this invention, the main body 11 of the bracket 1 and the reflector 3 are integrally formed, which saves costs. Because the light-emitting device provided by this utility model adopts a light source 2 that can emit light with adjustable wavelength, when the photographed object is used as a printing object and its surface has many colors and complex shapes, based on the selected feature area on the surface of the printing object, the light source 2 can be adjusted to output light of different wavelengths, which can artificially enhance the imaging effect of the feature area and suppress noise pollution. Thus, it can be compatible with different photographed objects, such as a wide variety of printing objects, and can adapt to different colors, materials, surface treatment processes, etc. of different photographed objects. Therefore, when different photographed objects are used as printing objects, there is no need to adjust the hardware structure, adjust the algorithm or other parameters to ensure the recognition effect of the digital image captured by the camera. Thus, it has the advantages of simple operation and good adaptability.

[0028] Please refer to the reference. Figure 3 and Figure 4 Preferably, the bracket 1 includes a pair of bracket bodies 11, and the reflectors 3 are respectively connected to one of the bracket bodies 11 and are spaced apart from each other. The space between the pair of reflectors 3 forms a shooting hole 4 for the camera to take pictures through. That is, in this specific embodiment of the present invention, the camera is positioned relative to the light source 2 and the reflectors 3, on the side further away from the light source 2 than the reflectors 3, and opposite to a shooting hole 4 located between the two reflectors 3. In this way, on the one hand, the entire light-emitting device has a compact structure, and on the other hand, it is conducive to the rational design and layout of the optical paths of each light source 2.

[0029] Please refer to the reference. Figure 3 and Figure 4Preferably, both the frame body 11 and the shooting hole 4 extend along a first direction. A light source 2 is fixed to the lower end of the inner sides of each pair of frame bodies 11 facing each other. A pair of reflectors 3 are respectively connected to the upper end of one of the inner sides, forming a reflective cavity between the inner sides of the pair of frame bodies 11. The side of the reflector 3 facing the reflective cavity is provided as a reflective arc surface. In this way, the reflective arc surface of each of the pair of reflectors 3 can match the illumination direction of the wavelength-tunable light from the light source 2, so that the wavelength-tunable light emitted by the light source 2 is uniformly reflected onto the subject and not directly emitted onto the camera. This ensures that the subject receives sufficient wavelength-tunable light illumination while avoiding the reduction in shooting quality caused by direct exposure of the wavelength-tunable light to the camera, thereby ensuring high image quality.

[0030] Preferably, the reflective arc surface is provided with a scattering structure layer that scatters light incident upon it. Therefore, by setting the scattering structure layer, the scattering effect of the reflective arc surface on light can be improved, thereby improving the imaging quality of the camera.

[0031] Specifically, the scattering structure layer is configured as a nano-scattering coating, a micro / nanopillar array, or a transparent porous structure. More specifically, for the nano-scattering coating, the following preparation method can be used: nanoparticles are mixed and dispersed uniformly with a dispersant, and then added to a film-forming agent, diluent, and ash-forming agent in a specific ratio, followed by thorough milling until uniformly mixed. The nanoparticle light-scattering filler includes rare earth oxides such as yttrium oxide, cerium oxide, and lanthanum oxide; silicon oxide; aluminum oxide; titanium oxide; zinc oxide; zinc sulfide; zirconium oxide; rare earth tri-color oxides; barium sulfate; barium carbonate; and barium titanate. The filler can be one of these powders or a mixture of two powders. The functional nano-coating also includes a film-forming agent and a diluent, with a ratio of 1:1 to 2:1. When the film-forming agent is nitrocellulose lacquer or acrylic acid, the diluent is a thinner; when the film-forming agent is polyvinyl butyral, the diluent is alcohol. For micro / nanopillar arrays, the scattering effect is achieved by utilizing their inherent properties of grating effect, scattering enhancement, interference effect, and local resonance. The grating effect refers to the fact that the micro / nanopillar array can be considered a diffraction grating. When wavelength-tunable light shines on this periodic structure, diffraction occurs, producing beams of multiple diffraction orders. The direction and intensity of the diffracted beams depend on the wavelength of the incident wavelength-tunable light, the size, spacing, and shape of the micro / nanopillars. Scattering enhancement refers to the fact that, in addition to diffraction, the pillars themselves also scatter light, similar to Mie scattering. When the size of the pillars is comparable to the wavelength of light, the scattering effect is very significant. By rationally designing the pillar parameters, the scattered light can be evenly distributed in all directions, thereby enhancing the overall scattering effect. The interference effect refers to the interference between diffracted beams, producing interference fringes, thus changing the intensity distribution of the scattered beam. By controlling the arrangement of the pillars, the interference effect can be modulated to achieve specific scattering modes. Local resonance refers to the phenomenon where, under certain special conditions, when light waves resonate with a pillar structure, a strong local electromagnetic field is formed around the pillar, thereby enhancing scattering efficiency. Furthermore, the micro / nanopillar array is fabricated using nanoimprinting, a process where a pre-prepared nanomold is pressed onto a substrate coated with a polymer film, followed by curing, thus transferring the pattern from the mold to the substrate. This process offers advantages such as low cost and the ability to manufacture large areas. Transparent porous materials are microstructures that effectively enhance light scattering. By rationally designing the pore size, porosity, shape, and connectivity, multiple scattering, the effective medium theory, Mie scattering, and the properties of photon localization can be utilized to achieve highly efficient diffusion effects. Multiple scattering refers to the multiple reflections, refractions, and diffractions that occur between the pore walls when light is incident on a porous material. Due to the randomness and irregularity of the pore walls, the incident light is scattered in various directions, thus enhancing the overall scattering effect. The effective medium theory states that porous materials can be considered as composite media with an effective refractive index. The effective refractive index depends on the refractive index and porosity of the matrix material and pores.By adjusting the porosity, the effective refractive index of a material can be controlled, thus affecting its scattering performance. Mie scattering refers to the phenomenon that occurs when the pore size is comparable to the incident light wavelength, further enhancing the scattering effect. Photon localization refers to the phenomenon that, under certain special conditions, when the porous structure has a certain periodicity, photon localization may occur, significantly enhancing scattering efficiency. Furthermore, when fabricating transparent porous structures, to ensure the light transmittance of the plate, aluminosilicate materials such as SiO2 or Al2O3, or transparent polymer materials such as polycarbonate, polymethyl methacrylate, and polystyrene are used. In addition, to obtain better scattering effects, the following points can be considered: Controlling pore size and porosity: Controlling the pore size between several hundred nanometers and several micrometers, and adjusting the porosity to obtain the best visible light scattering effect. Uniform distribution: Ensuring the pore structure is uniformly distributed throughout the coating. Mechanical strength: Considering the mechanical strength of the porous structure to avoid damage during coating. Protective layer: A transparent protective layer can be applied to prevent contamination or damage to the porous structure.

[0032] Please refer to the reference. Figure 5 Specifically, the light source 2 includes a light panel 21, multiple LED beads 22, and a light-transmitting dust cover 23. The dust cover 23 is placed on the light panel 21. The multiple LED beads 22 include three types of LED beads that emit R, G, and B light respectively. The LED beads can be LED beads. The three types of LED beads are arranged alternately on the light panel 21, which helps to improve the uniformity of light. Depending on the subject being photographed, each LED bead can be adjusted in terms of working wavelength, working color temperature, number of on / off states, and at least one of the color spots formed. This allows for targeted adjustment of wavelength-adjustable light according to the subject being photographed, so that different subjects can meet the lighting requirements of the camera and obtain high-quality digital images.

[0033] Preferably, the reflective arc surface is a parabolic surface, the length of the reflector 3 extending along the first direction is L, the distance between the LED 22 and the centerline of the shooting hole 4 is D, the vertical distance between the LED 22 and the reflector 3 is H, the width of the shooting hole 4 between the two reflectors 3 is W, and the divergence angle after reflection by the parabolic surface is θ. In order for the light emitted by the LED 22 to be uniformly reflected onto the subject by the reflective arc surface while not being directly emitted onto the camera, the following conditions must be met: θ≥θ min Where θ≈2tan -1 (Δ / 2f), Δ=Df, f is the focal length of the parabola. And W≤2D sinθ minTherefore, through the design of the above specific conditions, the technical effect of ensuring that the wavelength-tunable light cannot shine on the camera located above the shooting hole 4, while still being uniformly reflected onto the subject by the reflector 3, is achieved.

[0034] Please refer to the reference. Figure 3 and Figure 4 Preferably, the frame body 11 is made of metal material. A heat dissipation part 5 is provided on the outer surface of the pair of frame bodies 11 facing away from each other. The heat dissipation part 5 is a heat dissipation fin and / or heat dissipation groove. The heat dissipation part 5 can increase the contact area between the frame body 11 and the air, thereby improving the heat dissipation capacity of the light source 2 connected to the frame body 11. A cooling fan 6 is provided on the heat dissipation part 5, which further improves the heat dissipation capacity of the light source 2.

[0035] As another objective of this invention, a visual recognition device is also provided, comprising a camera and any of the aforementioned light-emitting devices. The camera captures images of a subject illuminated by wavelength-tunable light emitted from a light source 2 reflected by a reflector 3. The visual recognition device can achieve the beneficial effects provided by any of the light-emitting devices, which will not be elaborated further here. Since the light-emitting device of the visual recognition device has a light source 2 capable of emitting wavelength-tunable light, and the light source 2 is compatible with different subjects, there is no need to adjust the hardware structure, algorithm, or other parameters for different subjects with different colors, materials, surface treatment processes, etc., to ensure the recognition effect of the digital images captured by the camera. Therefore, the visual recognition device has the advantages of simple operation and good adaptability.

[0036] As another objective of this invention, a printing device is also provided, comprising a printhead, a belt, and any of the aforementioned visual recognition devices. The device is characterized in that the object to be photographed is a printed object conveyed by the belt to the area below the printhead, and the nozzle of the printhead sprays ink onto the printed object whose position is determined by the camera's image. The printing device can achieve the beneficial effects provided by any of the visual recognition devices, which will not be elaborated further here. Therefore, since the camera of the visual recognition device can use a light source 2, which is adaptable to various types of printed objects, to illuminate the printed object and capture a high-quality digital image, it can accurately analyze the position of the printed object based on the image, causing the nozzle to accurately spray ink onto the corresponding position of the printed object, thereby achieving excellent image printing quality.

[0037] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A light-emitting device, characterized in that, include: support; A light source, fixed on the bracket, provides wavelength-tunable light for the camera to take pictures; A reflector, mounted on the bracket, reflects the wavelength-tunable light onto the subject being photographed by the camera, located below the light source.

2. The light-emitting device according to claim 1, characterized in that, The bracket includes a pair of frame bodies, and the reflectors are respectively connected to one of the frame bodies and spaced apart from each other. The space between the pair of reflectors forms a shooting hole through which the camera takes pictures.

3. The light-emitting device according to claim 2, characterized in that, Both the frame body and the shooting hole extend along a first direction. A light source is fixed to the lower end of the inner side of a pair of frame bodies facing each other. A pair of reflectors are respectively connected to the upper end of one of the inner side. A reflective cavity is formed between the inner side of a pair of frame bodies. The side of the reflector facing the reflective cavity is set as a reflective arc surface.

4. The light-emitting device according to claim 3, characterized in that, The reflective arc surface is provided with a scattering structure layer that scatters light incident upon it.

5. The light-emitting device according to claim 4, characterized in that, The scattering structure layer is configured as a nano-scattering coating, a micro / nano pillar array, or a transparent porous structure. The micro / nano pillar array is prepared using a nanoimprinting process, and the transparent porous structure is made of aluminosilicate material or transparent polymer material.

6. The light-emitting device according to claim 3, characterized in that, The light source includes a lamp board, multiple LED beads, and a light-transmitting dust cover. The dust cover is placed on the lamp board. The multiple LED beads include three types of LED beads that emit R, G, and B light respectively. The three types of LED beads are arranged alternately on the lamp board. The working wavelength, working color temperature, number of on / off states, and / or color spots formed by each different LED bead can be adjusted according to the different subjects being photographed.

7. The light-emitting device according to claim 6, characterized in that, The reflective arc surface is designed as a parabolic surface. The length of the reflector extending along the first direction is L. The distance between the LED and the centerline of the shooting aperture is D. The vertical distance between the LED and the reflector is H. The width of the shooting aperture between the two reflectors is W. The divergence angle after reflection by the parabolic surface is θ. To ensure that the light emitted by the LED is uniformly reflected onto the subject by the reflective arc surface without being directly emitted onto the camera, the following conditions must be met: θ≥θ min ,in, Δ = Df, where f is the focal length of the parabola. as well as W≤2D sinθ min 。 8. The light-emitting device according to claim 2, characterized in that, The frame body is made of metal material. A heat dissipation part is provided on the outer surface of the two frame bodies facing away from each other. The heat dissipation part is a heat dissipation fin and / or heat dissipation groove, and a cooling fan is provided on the heat dissipation part.

9. A visual recognition device, comprising a camera and a light-emitting device as described in any one of claims 1-8, wherein the camera captures an object illuminated by the wavelength-tunable light reflected from the reflector.

10. A printing apparatus, comprising a printhead, a belt, and a visual recognition device as described in claim 9, characterized in that, The subject being photographed is a printed object conveyed by the belt to the area below the printhead, and the nozzle of the printhead sprays ink onto the printed object whose position is determined by the camera's image capture.

Images