Integrated 3D printing method based on integrated lens array

Abstract

This invention discloses an integrated 3D printing method based on an integrated lens array, belonging to the fields of integrated imaging, light field 3D imaging, and additive manufacturing technology. The method first acquires an integrated image of a 3D model; then, it scales the integrated image to obtain an integrated image suitable for 3D projection onto the integrated lens array; next, it projects the integrated image onto the integrated lens array using a main-view lens or lens group, generating a 3D real image projection of the object; then, it uses a transparent container with light-filtering and anti-reflection properties to hold liquid photosensitive resin; finally, it places the container holding the liquid photosensitive resin in the 3D real image projection area of ​​the object, completely enveloping the projection, and waits for the photocuring reaction to complete to obtain the 3D printed product. The method described in this invention is simple to implement, requires no complex mechanical structure, is easy to operate, and has strong practicality and scalability.

Description

Technical Field

[0001] This invention belongs to the fields of integrated imaging, light field three-dimensional imaging and additive manufacturing technology, and specifically relates to an integrated 3D printing method based on an integrated lens array. Background Technology

[0002] Light field 3D imaging technology is an advanced method for capturing and representing the shape and depth of objects in three-dimensional space. Based on the principle of light field, it uses multiple viewpoints and lens arrays to capture light information at different angles and focal planes. The unit images acquired from different viewpoints are arranged in a corresponding order and synthesized into an image called an integrated image. Through subsequent processing of the integrated image, high-quality reconstruction and visualization of the 3D scene can be achieved. This process is also known as image acquisition in integrated imaging technology.

[0003] Light field 3D imaging technology originated in 1936 when Gershun first proposed the concept of the all-optical function while studying the propagation characteristics of light. The four-dimensional light field function, derived from this simplified version, became the main research object in the field of light field imaging. To date, it has been applied in numerous areas such as light field cameras, naked-eye 3D imaging, and virtual light field displays.

[0004] Additive manufacturing (AM) is an industrial manufacturing technology, also known as 3D printing. Unlike traditional manufacturing methods, additive manufacturing creates three-dimensional objects by layering materials, rather than removing material from raw materials through cutting or shaving to achieve the desired shape. The application of additive manufacturing technology significantly reduces the production cycle and cost of customized manufacturing, and also substantially lowers the mold opening and testing costs for large-scale manufacturing. Furthermore, it provides fundamental support for the upgrading and restoration of old components in specialized fields such as aerospace and medical implants.

[0005] The existing technology document, "The History of 3D Printing: From the 80s to Today," recounts the rapid development of the 3D printing concept since its introduction by Hideo Kodama in the 1980s. In 1986, Charles Hull invented the world's first 3D printing technology, SLA (Stereolithography, which uses light (usually ultraviolet light) to solidify liquid photosensitive resin materials to create objects). This technology uses a laser beam to scan the pattern of a model slice, solidifying the photosensitive resin layer by layer. This ushered in the era of rapid prototyping (RP) through layer-by-layer additive manufacturing, significantly reducing material costs compared to traditional mold-making methods such as cutting and milling. Subsequently, SLS (Selective Laser Sintering, which uses lasers to melt special powdered resin materials to create objects layer by layer) and FDM (Fused Deposition Modeling, which creates objects layer by layer by extruding molten material) were invented by Carl Deckard and Scott Crump, respectively. Each of these three technologies has its own advantages in addressing different rapid modeling needs, and they are also the main additive manufacturing technologies currently used in the market.

[0006] The existing technology "Based on visible light of the mask projectionstereolithography" discloses a surface projection SLA photopolymerization method, which further improves the printing efficiency of SLA based on the traditional point-to-point printing method. At the same time, it has significant advantages in terms of accuracy, precision and printing quality compared with the other two traditional methods. However, the printing speed still faces challenges because the photopolymerization process requires waiting for the material to fully stabilize. Summary of the Invention

[0007] The purpose of this invention is to overcome the shortcomings of the prior art and provide an integrated 3D printing method based on an integrated lens array.

[0008] The technical problem addressed by this invention is solved as follows:

[0009] A monolithic 3D printing method based on an integrated lens array includes the following steps:

[0010] Step 1. By taking photos of the actual object or by modeling and rendering, obtain a clear and complete integrated image array of the target object from several angles with uniformly spaced angles on the same horizontal plane centered on the target object.

[0011] Step 2. For each integrated image array acquired from each angle, a corresponding real image projection device is provided, including a display device, a main viewing angle lens and an integrated array lens; each set of real image projection devices is located on the same horizontal plane centered on the 3D printing position, and the included angle between two adjacent sets of real image projection devices is the same as in Step 1.

[0012] The size of the integrated image array of the target object at each angle is adjusted by computer so that the integrated image array at each angle is completely output on the corresponding display device. At the same time, the integrated image array output by the display device can be completely output on the integrated lens array through the main viewing angle lens.

[0013] Step 3. In each group of real image projection devices, the integrated image array is output from the display device and further output through the main viewing angle lens onto the integrated lens array; the integrated lens array recombines the integrated image array output from the display device to form a real image projection of the target object at the corresponding angle; the real image projections of the target object at each angle formed by all real image projection devices are superimposed on each other at the 3D printing position to output a complete real image projection of the target object.

[0014] Step 4. Construct a container using a material that is transparent to light of a set wavelength and suppresses light of other wavelengths. Fill the container with a photosensitive resin liquid that is sensitive to light of the corresponding set wavelength. When the photosensitive resin liquid is irradiated with light of the corresponding set wavelength, it will undergo a phase change and solidify into a solid.

[0015] Step 5. Place the container prepared in Step 4 at the 3D printing location so that the container completely encloses the real image projection of the object; through the photocuring reaction of the photosensitive resin liquid, the photosensitive resin liquid in the area where the real image projection of the target object is located will gradually solidify and form a one-piece molded 3D printed model.

[0016] Furthermore, in step 1, on a horizontal plane centered on the target object, at intervals of 120°, an integrated image array of the target object at three angles is acquired, including the three-dimensional spatial information of the target object in these three angular directions.

[0017] Furthermore, in step 1, the integrated image array of the target object is acquired by means of physical object shooting. The integrated image array of the target object is acquired by arranging the target object, integrated lens array, and shooting device.

[0018] Furthermore, in step 1, the integrated image array of the target object is obtained through modeling and rendering. Computer modeling is used to create a virtual camera array, which is then rendered from the camera's perspective and synthesized into a complete image in sequence, thereby obtaining the integrated image array.

[0019] Furthermore, display devices include flat panel displays, laser projectors, and LED display arrays. Flat panel displays include liquid crystal flat panel displays, cathode ray displays, and mini-LED displays.

[0020] Furthermore, in step 3, the distance g from the main viewing lens to the integrated lens array, the focal length f of the integrated lens array, and the distance l between the integrated lens array and the 3D printing location satisfy the Gaussian imaging formula. And it satisfies g>f and l>0.

[0021] Furthermore, in step 4, the wavelength is set to 200-800nm. The material used to build the container is transparent to light in the 200-800nm ​​wavelength range and can filter out light in other wavelength ranges. The material used for the photosensitive resin liquid is any one of the following that meets the set wavelength range: free radical photocuring, cationic photocuring, free radical-cationic hybrid photocuring, and mercapto-olefin photopolymerization system. It is sensitive to light in the 200-800nm ​​wavelength range and will undergo a polymerization reaction when irradiated, thus completing the curing process.

[0022] Furthermore, a support platform is set at the bottom area of ​​the real image projection of the target object to prevent the molded part from moving in the photosensitive resin container due to gravity during the printing process, which could lead to the failure of the entire printing process.

[0023] The beneficial effects of this invention are:

[0024] The method described in this invention is the first to use an integrated lens array-based approach to achieve one-piece 3D printing of objects. It uses an integrated image reconstruction method to obtain the three-dimensional information of the object contained in the integrated image and reconstruct it into a 3D projection of the object. Unlike the existing layered additive manufacturing method, the method described in this invention improves printing efficiency and longitudinal strength of the printed product while molding in one step.

[0025] Based on the properties of the integrated lens array, the method described in this invention employs the SLA photosensitive resin printing method, which has significant advantages over other widely used additive manufacturing methods in terms of printing efficiency and simplified printing equipment structure.

[0026] The method described in this invention has the characteristics of not requiring mechanical structures and being formed in one piece in a single step. The basic example structure is not only simple to implement and easy to operate, but also has strong practicality and is suitable for widespread use. Attached Figure Description

[0027] Figure 1 This is a flowchart illustrating the method described in this invention;

[0028] Figure 2 This is a flowchart illustrating the physical object photography method described in the present invention.

[0029] Figure 3 This is a flowchart illustrating the structural process of the modeling and rendering method described in this invention. Detailed Implementation

[0030] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0031] This embodiment provides an integrated 3D printing method based on an integrated lens array. The photopolymerization 3D printing using an integrated lens array can shape the printed object in a single exposure, which has the advantages of high efficiency, precision, and material saving. This integrated 3D printing method based on an integrated lens array is simple to implement, does not have a complex mechanical structure, is easy to operate, and has strong practicality and scalability.

[0032] The flowchart of the method described in this embodiment is shown below. Figure 1 The process shown (only one angle is displayed) includes the following steps:

[0033] Step 1. First, perform Integral Imaging to acquire integrated images. Through physical photography or modeling and rendering, obtain a clear and complete integrated image array II of the target object from several angles at even intervals on the same horizontal plane centered on the target object.

[0034] In this embodiment, on a horizontal plane centered on the target object, at intervals of 120°, an integrated image array of the target object at three angles is acquired, including the three-dimensional spatial information of the target object in these three angular directions.

[0035] The flowchart of the structure of the integrated image array for acquiring target objects through physical object photography is as follows: Figure 2 As shown, the target object, integrated lens array, and imaging device are positioned to acquire an integrated image array of the target object; the CMR camera directly captures the physical object RO through the integrated lens array LA to obtain a complete integrated image II. This is the most intuitive and fastest method for acquiring integrated images.

[0036] The flowchart of obtaining the structure of the integrated image array of the target object through modeling and rendering is as follows: Figure 3 As shown, computer modeling is used to create a virtual camera array. The images are rendered from the camera's perspective and synthesized sequentially to obtain an integrated image array. First, a target object model VM and a virtual camera array V-CMRA are created in 3D modeling software using a PC. Each virtual camera in the virtual camera array renders the image from the current perspective. Then, the rendered sub-images are arranged and integrated in the PC, and finally, the complete integrated image II is output.

[0037] Step 2. For each integrated image array obtained at each angle, a corresponding real-image projection device is equipped, including a display device D, a main perspective lens FL, and an integrated array lens LA; each group of real-image projection devices is located on the same horizontal plane centered on the 3D printing position, and the interval angle between adjacent two groups of real-image projection devices is the same as that in Step 1;

[0038] The computer PC is used to adjust the sizes of the integrated image arrays of the target object at each angle respectively, so that the integrated image arrays at each angle are completely output on the corresponding display device, and at the same time, the integrated image arrays output by the display device can be completely output on the integrated lens array through the main perspective lens.

[0039] The main purpose of adjusting the image size at the pixel level is to ensure the image pixel accuracy when using the same display device, and also ensure the 3D imaging quality.

[0040] In each group of real-image projection devices, the integrated image array is output on the display device and further output on the integrated lens array through the main perspective lens; the integrated lens array recombines the integrated image arrays output by the display device to form a real-image projection of the target object at the corresponding angle; the real-image projections of the target object at each angle formed by all real-image projection devices are superimposed on each other at the 3D printing position, so as to output a complete real-image projection of the target object.

[0041] The display device is not limited to ordinary flat display devices, such as liquid crystal flat panel displays, cathode ray displays, mini-LED displays, etc.; it should also include laser projectors, LED display arrays, etc.; the main perspective lens can completely transmit the light emitted by the integrated image array on the display device and filter out clutter, increasing the purity of the image signal.

[0042] According to the Gaussian imaging formula, the mutual relationship between the distance g from the display device to the integrated lens array and the focal length f of the integrated lens array is controlled, and the distance l from the integrated lens array to the center of the imaging area is controlled to achieve the correct display effect of the three-dimensional real-image projection of the object. The lens imaging methods are divided into three types: virtual image, real image, and simultaneous focusing; the Gaussian imaging formula is as follows:

[0043]

[0044] When g > f, l > 0, and the three-dimensional projection of the object presents a real image;

[0045] When g < f, l < 0, and the three-dimensional projection of the object presents a virtual image;

[0046] When g = f, l → ∞, and the three-dimensional projection of the object is simultaneously focused in the imaging areas of virtual image and real image, but in this case, the spatial resolution of the object real image is relatively low.

[0047] For the three-dimensional real image projection of the object in the method described in this embodiment, the distance g from the main viewing lens to the integrated lens array, the focal length f of the integrated lens array, and the distance l between the integrated lens array and the 3D printing location satisfy the Gaussian imaging formula. And it satisfies g>f and l>0.

[0048] Step 4. Construct a printing container using a material that is transparent to light of a set wavelength and suppresses light of other wavelengths. Fill the container with a photopolymer that is sensitive to light of the corresponding set wavelength. After the container filters out noise, it improves the absorption and utilization efficiency of the photopolymer on the three-dimensional real image energy of the target object. When the photopolymer is irradiated by light of the corresponding set wavelength, it will undergo a phase change and solidify into a solid.

[0049] In this embodiment, the wavelength is set to 200-800nm. The material used to build the container is transparent to light in the 200-800nm ​​wavelength range and can filter out light in other wavelength ranges. The photosensitive resin liquid is any one of the following systems that meets the set wavelength range: free radical photocuring, cationic photocuring, free radical-cationic hybrid photocuring, and mercapto-olefin photopolymerization system. It is sensitive to light in the 200-800nm ​​wavelength range and will undergo a polymerization reaction when irradiated, thus completing the curing process.

[0050] Step 5. Place the container prepared in Step 4 at the 3D printing location so that the container completely encloses the real image projection of the object; through the photocuring reaction of the photosensitive resin liquid, the photosensitive resin liquid in the area where the real image projection of the target object is located will gradually solidify and form a one-piece molded 3D printed model.

[0051] The process described in step 5, where the 3D real image projection area of ​​the object in the photosensitive resin is cured into a single model, does not require model layering or printing platform movement. The printed model is formed in a single projection. A support platform (Base) can be set at the bottom area of ​​the 3D real image projection to prevent the already formed part from moving within the photosensitive resin container due to gravity during the printing process, which could lead to the failure of the entire printing process.

[0052] In summary, this invention innovatively utilizes a method combining integrated lens arrays and SLA photosensitive resin printing to achieve one-piece 3D printing of objects. Unlike existing layer-by-layer additive manufacturing methods, it improves molding speed and longitudinal strength of the finished product while simultaneously achieving one-time molding. It significantly outperforms other widely used additive manufacturing methods in terms of printing efficiency and longitudinal strength of the printed product. This invention also features the advantages of requiring no mechanical structure and achieving one-piece, single-step molding. It is not only simple to implement and easy to operate, but also has low manufacturing costs and strong practicality, making it suitable for widespread promotion in this and related technical fields.

[0053] The structures listed above are merely basic structures for illustrative purposes and should not be used to limit the scope of protection of this invention. Any modifications or refinements made to the main design concept and spirit of this invention that are not of substantial significance but still solve the same technical problem as this invention should be included within the scope of protection of this invention.

Claims

1. An integrated 3D printing method based on an integrated lens array, characterized in that, Includes the following steps: Step 1. By taking photos of the actual object or by modeling and rendering, obtain a clear and complete integrated image array of the target object from several angles with uniformly spaced angles on the same horizontal plane centered on the target object. On a horizontal plane centered on the target object, at intervals of 120°, an integrated image array of the target object at three angles is acquired, including the three-dimensional spatial information of the target object in these three angular directions. An integrated image array of the target object is acquired by means of physical object photography. The integrated image array of the target object is acquired by placing the target object, the integrated lens array, and the shooting device. The integrated image array of the target object is obtained by modeling and rendering. Computer modeling is used to create a virtual camera array, which is then rendered from the camera's perspective and synthesized into a complete image in sequence to obtain the integrated image array. Step 2. For each integrated image array acquired from each angle, a corresponding real image projection device is provided, including a display device, a main viewing angle lens and an integrated array lens; each set of real image projection devices is located on the same horizontal plane centered on the 3D printing position, and the included angle between two adjacent sets of real image projection devices is the same as in Step 1. The size of the integrated image array of the target object at each angle is adjusted by computer so that the integrated image array at each angle is completely output on the corresponding display device. At the same time, the integrated image array output by the display device can be completely output on the integrated lens array through the main viewing angle lens. Step 3. In each group of real image projection devices, the integrated image array is output from the display device and further output through the main viewing angle lens onto the integrated lens array; the integrated lens array recombines the integrated image array output from the display device to form a real image projection of the target object at the corresponding angle; the real image projections of the target object at each angle formed by all real image projection devices are superimposed on each other at the 3D printing position to output a complete real image projection of the target object. Step 4. Construct a container using a material that is transparent to light of a set wavelength and suppresses light of other wavelengths. Fill the container with a photosensitive resin liquid that is sensitive to light of the corresponding set wavelength. When the photosensitive resin liquid is irradiated with light of the corresponding set wavelength, it will undergo a phase change and solidify into a solid. The wavelength is set at 200-800nm. The material used to build the container is transparent to light in the 200-800nm ​​wavelength range and can filter out light in other wavelength ranges. The photosensitive resin liquid is any one of the following systems that meets the set wavelength range: free radical photocuring, cationic photocuring, free radical-cationic hybrid photocuring, and mercapto-olefin photopolymerization system. It is sensitive to light in the 200-800nm ​​wavelength range and will undergo a polymerization reaction when exposed to light, thus completing the curing process. Step 5. Place the container prepared in Step 4 at the 3D printing location, so that the container completely encloses the real image projection of the object; through the photocuring reaction of the photosensitive resin liquid, the photosensitive resin liquid in the area where the real image projection of the target object is located will gradually solidify and form a one-piece molded 3D printed model.

2. The integrated 3D printing method based on an integrated lens array according to claim 1, characterized in that, Display devices include flat panel displays, laser projectors, and LED display arrays. Flat panel displays include liquid crystal flat panel displays, cathode ray displays, and mini-LED displays.

3. The integrated 3D printing method based on integrated lens array of claim 1, wherein, In step 3, the distance from the main viewing lens to the integrated lens array... g Focal length of integrated lens array f The distance between the integrated lens array and the 3D printing location l Satisfying the Gaussian imaging formula And satisfy g > f , l >0.

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