Digital 3D printing method for artware

Abstract

The invention discloses an artware digital 3D printing method which comprises the following steps: S1, collecting geometric structure and surface texture data of a target artware, and generating a holographic data file containing complete three-dimensional geometric information; s2, performing phase modulation calculation on the three-dimensional data through a holographic phase modulation algorithm; s3, modulating the loaded light field modulation pattern matrix through a spatial light modulator; s4, performing volume photopolymerization reaction on the photosensitive resin in the light field reconstruction region by using a multi-photon absorption mechanism to form a three-dimensional structure; s5, holographic light field projection time and light intensity distribution of the multiband laser source are adjusted; s6, the formed three-dimensional artware is treated; and S7, analyzing the three-dimensional shapes of the formed handicraft and the target handicraft by using a shape error analysis technology, and inputting an error analysis result into a holographic phase modulation unit. The method has the advantages of high printing precision, excellent surface quality, high forming efficiency and high material adaptability.

Description

Technical Field

[0001] The present invention relates to the technical field of 3D printing, and in particular to a digital 3D printing method for handicrafts. Background Art

[0002] With the rapid development of 3D printing technology and digital processing technology, the digitization and high-precision reproduction of traditional handicrafts have become a research hotspot in the field of process design and manufacturing. 3D printing technology for the digitalization of handicrafts can play an important role in preserving cultural heritage, reproducing and creating handicrafts. However, since handicrafts usually have complex surfaces, high-precision textures and diverse materials, existing technologies face many challenges in achieving high-precision digitization and three-dimensional molding.

[0003] In the existing technology, digital 3D printing methods for handicrafts mostly rely on traditional additive manufacturing technology of layer-by-layer stacking and digital methods based on surface scanning. These methods have the following main problems:

[0004] 1. Limitations of complex surface data acquisition: Traditional surface scanning methods often find it difficult to collect comprehensive and accurate geometric information when dealing with complex surfaces of handicrafts, resulting in defects in the reconstruction of three-dimensional models.

[0005] 2. Insufficient precision of layer-by-layer stacking: Traditional 3D printing technology uses a layer-by-layer stacking method, which easily forms seams between layers, affecting the overall surface quality and detail accuracy of the printed crafts.

[0006] 3. Low printing efficiency: Due to the nature of layer-by-layer printing, traditional additive manufacturing technology takes a long time to print complex structures and is difficult to meet the needs of efficient manufacturing.

[0007] 4. Poor material adaptability: The existing technology has limited choices for printing materials and is difficult to support high-precision printing in scattering media or non-absorbent materials.

[0008] Therefore, how to provide a digital 3D printing method for handicrafts is an urgent problem that technicians in this field need to solve. Summary of the invention

[0009] One purpose of the present invention is to propose a digital 3D printing method for handicrafts based on holographic volumetric additive manufacturing technology. The present invention makes full use of holographic phase modulation technology, multi-photon absorption mechanism and light field optimization algorithm, and describes in detail the specific steps of realizing high-precision digital acquisition and one-time three-dimensional molding of complex surfaces. It has the advantages of high printing accuracy, excellent surface quality, fast molding efficiency and strong material adaptability.

[0010] A digital 3D printing method for handicrafts according to an embodiment of the present invention comprises the following steps:

[0011] S1. Use a holographic scanning device to perform holographic scanning on the target craftwork, collect the geometric structure and surface texture data of the target craftwork by recording the light field phase and amplitude information, and generate a holographic data file containing complete three-dimensional geometric information;

[0012] S2, inputting the holographic data file into the holographic phase modulation unit, performing phase modulation calculation on the three-dimensional data through the holographic phase modulation algorithm, generating a light field modulation pattern matrix with three-dimensional morphology information, and loading the holographic phase map into the spatial light modulator;

[0013] S3, modulating the loaded light field modulation pattern matrix through a spatial light modulator, projecting the three-dimensional geometric information into the target printing area in the form of a dynamic light field, and reconstructing a holographic light field consistent with the geometric shape of the craftwork;

[0014] S4, filling the target printing area with a photosensitive resin material, acting on the holographic light field through a multi-band laser source, and utilizing a multi-photon absorption mechanism to cause a volume photopolymerization reaction of the photosensitive resin in the light field reconstruction area to form a three-dimensional structure;

[0015] S5. Adjust the projection time of the holographic light field and the light intensity distribution of the multi-band laser source to make the resin photopolymerization reaction uniform and accurate, so as to realize the one-time molding of the three-dimensional structure of the handicraft;

[0016] S6. Process the formed three-dimensional crafts, including removing unreacted materials, surface smoothing and curing enhancement operations, to ensure the surface quality and overall stability of the printed crafts;

[0017] S7. Use shape error analysis technology to analyze the three-dimensional morphology of the molded craftwork and the target craftwork, input the error analysis results into the holographic phase modulation unit, and optimize the holographic phase modulation algorithm and projection parameters.

[0018] Optionally, the S2 specifically includes:

[0019] S21, inputting the three-dimensional geometric information and surface texture data in the holographic data file into the holographic phase modulation unit, and defining the input data matrix D by extracting the light field amplitude and phase distribution of the holographic data file. input ={A(x, y), φ(x, y)}, where A(x, y) represents the amplitude distribution of the light field, and φ(x, y) represents the phase distribution of the light field;

[0020] S22, based on the holographic phase modulation algorithm, the input data matrix D input Convert to a three-dimensional phase target matrix D 3D ={P(x, y, z)}, where {P(x, y, z)} represents the phase distribution of the three-dimensional morphology information of the craft;

[0021] S23, for the three-dimensional phase target matrix D 3D Perform light field encoding processing and generate the light field modulation pattern matrix T through the digital holographic algorithm mod =G(D 3D ), where G represents a light field encoding function, which is used to convert three-dimensional shape information into a two-dimensional phase distribution required for spatial light modulation;

[0022] S24, the light field modulation pattern matrix T mod Loading to the spatial light modulator, adjusting the phase modulation parameters of the light modulator, so that the modulated dynamic light field can restore the three-dimensional shape information of the target;

[0023] S25, real-time interference analysis of the loaded light field modulation pattern T mod Calibration is performed to verify the matching degree between the phase distribution and amplitude distribution of the light field modulation pattern and the target three-dimensional morphology information.

[0024] Optionally, the S22 specifically includes:

[0025] S221, based on the input data matrix D input = {A(x, y), φ(x, y)} extracts the two-dimensional amplitude distribution A(x, y) and the two-dimensional phase distribution φ(x, y), and maps the two-dimensional phase distribution to the initial point cloud {P i (x i ,y i , z i )}:

[0026]

[0027] Among them, x i , yi is the two-dimensional coordinate, φ(x i ,y i ) is the phase information, k is the scalar conversion factor from phase to depth, and N is the total number of point clouds;

[0028] S222, for the initial point cloud {P i (x i ,y i , z i )} Apply the shape optimization function f opt (P) Perform three-dimensional phase correction to generate an optimized three-dimensional morphology point cloud {P′ i (x′ i , y′ i , z′ i )}:

[0029] P′ i (x′ i , y′ i, z′ i ) = f opt (Pi)=(x i +Δx,y i +Δy,z i +Δz);

[0030] Among them, Δx, Δy, Δz are based on the optimization function f opt The correction offset of

[0031] S223, the optimized three-dimensional morphology point cloud {P′ i (x′ i , y′ i , z′ i )} is converted to a three-dimensional phase target matrix D 3D ={P(x, y, z)}, where {P(x, y, z)} represents the phase distribution of the three-dimensional morphology information of the craft.

[0032] Optionally, the S23 specifically includes:

[0033] S231, for the three-dimensional phase target matrix D 3D = {P(x, y, z)} performs discrete Fourier transform to generate the frequency domain representation matrix F 3D ={F(u, V， w)}:

[0034]

[0035] Among them, F(u, V， w) represents the information of three-dimensional phase distribution in the frequency domain, and u, v, and w are the frequency domain coordinates;

[0036] S232, frequency domain representation matrix F 3D Perform two-dimensional projection processing to project the three-dimensional frequency domain information onto the plane frequency domain matrix F 2D ={F(u, v)} to retain the main information components in the frequency domain:

[0037]

[0038] Among them, F(u, v) represents two-dimensional frequency domain information;

[0039] S233, based on the light field coding function G(F 2D ) for the plane frequency domain matrix F 2D Perform phase encoding processing to generate the light field modulation pattern matrix T mod :

[0040] T mod (x, y) = arg[G(F 2D )];

[0041] Where arg represents the phase extraction operation, T mod (x, y) is the two-dimensional phase distribution of the light field modulation pattern matrix in spatial coordinates.

[0042] Optionally, the S4 specifically includes:

[0043] S41, filling the target printing area with a photosensitive resin material, and controlling the concentration of the photosensitive resin material to remain stable in the target area through a uniform distribution device;

[0044] S42, the light field modulation pattern matrix T mod (x, y) is loaded into the spatial light modulator, and after the coherent beam projection of the laser source, a holographic light field H(x, y, z) is generated:

[0045]

[0046] Wherein, K(x, y, z) represents the point spread function of light field propagation, and H(x, y, z) represents the holographic light field in the target printing area;

[0047] S43, superimposing the generated holographic light field H(x, y, z) with the composite light field of the multi-band laser source, and combining the laser frequency {f n}Form a composite light field L(x, y, z, t);

[0048] S44, under the action of the composite light field L(x, y, z, t), stimulating the multi-photon absorption mechanism in the photosensitive resin material, initiating a volume photopolymerization reaction of the photosensitive resin material through the multi-photon absorption, so that the resin material is cured in the composite light field focusing area to generate a three-dimensional structure;

[0049] S45, controlling the projection time of the composite light field and the laser intensity distribution to ensure that the polymerization reaction is limited to the target printing area, thereby forming the boundary of the target three-dimensional structure.

[0050] Optionally, the S43 specifically includes:

[0051] S431, inputting the generated holographic light field H(x, y, z) into a light field control device, controlling the phase distribution and light intensity distribution of the holographic light field in the target printing area, so that the light field energy is concentrated in the target printing area and matches the three-dimensional morphology information;

[0052] S432, setting the laser frequency combination of the multi-band laser source {f n}, generate laser intensity distribution I n (x, y, z):

[0053]

[0054] Where I0 is the initial laser intensity, α n is the attenuation coefficient, r(x, y, z) represents the propagation distance of the light field;

[0055] S433, laser intensity distribution of superimposed multi-band laser sources I n (x, y, z) and the holographic light field H(x, y, z) to generate a composite light field L(x, y, z, t):

[0056]

[0057] Among them, f n is the laser frequency, φ n is the phase delay, t is the time, and M is the total number of laser frequencies.

[0058] Optionally, the S44 specifically includes:

[0059] S441. Under the action of the composite light field L(x, y, z, t), the photosensitive molecules in the photosensitive resin material absorb multiple photon energies, stimulating the multi-photon absorption mechanism in the photosensitive resin material, stimulating it to a high energy state, triggering a chemical reaction of the molecular bonds, and the multi-photon absorption rate is:

[0060]

[0061] Among them, R abs (x, y, z) is the multiphoton absorption rate, σ abs is the absorption cross-section coefficient, k abs is the photon absorption order, I n (x, y, z) is the intensity distribution of the nth laser component at the target position, and M is the total number of laser frequencies;

[0062] S442, generating free radicals through multi-photon absorption, polymerizing the monomers in the photosensitive resin material into polymer chains, and the polymerization rate of the photopolymerization reaction is:

[0063] R poly (x, y, z) = η poly ·R abs (x, y, z);

[0064] Among them, R poly (x, y, z) is the polymerization rate, η poly is the polymerization efficiency coefficient, R abs (x, y, z) is the multiphoton absorption rate;

[0065] S443. Control the spatial distribution and projection time of the composite light field L (x, y, z, t) so that the polymerization reaction is limited to the target area. By adjusting the light field parameters, the spatial accuracy of the polymerization reaction is optimized to generate a three-dimensional structure.

[0066] Optionally, the S7 specifically includes:

[0067] S71. Scan the three-dimensional shape of the molded craftwork to obtain a point cloud data set D of the actual shape. actual = {Q a (x a ,y a , z a )}, where Q a (x a ,y a , z a ) represents the point coordinates of the actual printed surface;

[0068] S72, a three-dimensional shape data set D of the target craftwork target = {Q t (x t ,y t , z t )} and compare it with the actual shape point cloud data set D actual For registration, the rigid transformation matrix M align Align the two:

[0069] Q′ a (x′ a , y′ a , z′ a )=M align Q a (x a ,y a , z a );

[0070] Among them, Q′ a (x′ a , y′ a , z′ a ) is the aligned point cloud data, M align Contains rotation and translation parameters;

[0071] S73. Calculate the shape error ΔE(x, y, z) between the aligned point cloud data:

[0072]

[0073] Wherein, ΔE(x, y, z) represents the Euclidean distance error between the target artifact and the formed artifact;

[0074] S74, inputting the shape error distribution ΔE(x, y, z) into the holographic phase modulation unit, optimizing the parameters of the holographic phase modulation algorithm, and adjusting the phase modulation distribution matrix and the light field projection parameters through an iterative algorithm;

[0075] S75. Update the holographic light field generation and projection control data according to the optimized phase modulation distribution matrix and projection parameters.

[0076] Optionally, the S74 specifically includes:

[0077] S741, input the shape error distribution ΔE(x, y, z) into the holographic phase modulation unit, and map it to a two-dimensional phase error matrix ΔΦ(x, y):

[0078] ΔΦ(x, y) = f map (ΔE(x, y, z));

[0079] Among them, f map is the error mapping function, ΔΦ(x, y) is the two-dimensional phase error distribution of the target printing area;

[0080] S742, based on the two-dimensional phase error matrix ΔΦ(x, y), optimize the phase modulation distribution matrix T by an iterative algorithm mod-opt (x, y):

[0081]

[0082] in, is the phase modulation matrix of the kth iteration, α is the step size factor, is the gradient distribution of phase error;

[0083] S743. Adjust the projection parameters of the holographic light field according to the optimized phase modulation distribution matrix, and perform simulation verification on the optimized phase modulation distribution matrix and the projection parameters of the holographic light field to verify whether the optimization effect meets the accuracy requirements. If not, return to step S742 for further iteration.

[0084] The beneficial effects of the present invention are:

[0085] (1) The present invention provides high-precision digital processing and printing of complex craft surfaces and details by combining holographic phase modulation technology, multiphoton absorption mechanism and light field optimization algorithm, so that the system can accurately restore the complex structure of the craft, thereby effectively solving the problems of incomplete surface data collection and insufficient printing accuracy in the prior art. In particular, in the reproduction of crafts with high complexity and high precision requirements, the present invention significantly improves the molding quality.

[0086] (2) The present invention uses one-time three-dimensional molding technology, combined with the efficient generation of holographic light fields and the energy control of multi-band lasers, to significantly improve the printing efficiency of handicrafts and reduce the time-consuming problem of traditional layer-by-layer stacking methods. At the same time, by optimizing light field parameters and projection algorithms, printing errors are effectively reduced, achieving fast and accurate printing effects.

[0087] (3) The present invention supports high-precision printing in scattering media and non-absorbent materials through precise control of the light field and application of multi-photon absorption mechanism, expanding the scope of application of printing materials. Combined with iterative adjustment of error analysis and optimization algorithms, it can continuously optimize printing quality and consistency, providing an intelligent and automated solution for the digitization and reproduction of complex crafts. BRIEF DESCRIPTION OF THE DRAWINGS

[0088] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0089] Figure 1 This is a general process framework diagram of a digital 3D printing method for handicrafts proposed in the present invention. DETAILED DESCRIPTION

[0090] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, which only illustrate the basic structure of the present invention in a schematic manner, and therefore only show the components related to the present invention.

[0091] refer to Figure 1 A digital 3D printing method for handicrafts, characterized in that it includes the following steps:

[0092] S1. Use a holographic scanning device to perform holographic scanning on the target craftwork, collect the geometric structure and surface texture data of the target craftwork by recording the light field phase and amplitude information, and generate a holographic data file containing complete three-dimensional geometric information;

[0093] S2, inputting the holographic data file into the holographic phase modulation unit, performing phase modulation calculation on the three-dimensional data through the holographic phase modulation algorithm, generating a light field modulation pattern matrix with three-dimensional morphology information, and loading the holographic phase map into the spatial light modulator;

[0094] In this implementation, S2 specifically includes:

[0095] S21, inputting the three-dimensional geometric information and surface texture data in the holographic data file into the holographic phase modulation unit, and defining the input data matrix D by extracting the light field amplitude and phase distribution of the holographic data file. input ={A(x,y),φ(x,y)}, where A(x,y) represents the amplitude distribution of the light field, and φ(x,y) represents the phase distribution of the light field;

[0096] S22, based on the holographic phase modulation algorithm, the input data matrix D input Convert to a three-dimensional phase target matrix D 3D={P(x,y,z)}, where {P(x,y,z)} represents the phase distribution of the three-dimensional morphology information of the craft;

[0097] S23, for the three-dimensional phase target matrix D 3D Perform light field encoding processing and generate the light field modulation pattern matrix T through the digital holographic algorithm mod =G(D 3D ), where G represents a light field encoding function, which is used to convert three-dimensional shape information into a two-dimensional phase distribution required for spatial light modulation;

[0098] S24, the light field modulation pattern matrix T mod Loading to the spatial light modulator, adjusting the phase modulation parameters of the light modulator, so that the modulated dynamic light field can restore the three-dimensional shape information of the target;

[0099] S25, real-time interference analysis of the loaded light field modulation pattern T mod Calibration is performed to verify the matching degree between the phase distribution and amplitude distribution of the light field modulation pattern and the target three-dimensional morphology information.

[0100] In this implementation, S22 specifically includes:

[0101] S221, based on the input data matrix D input = {A(x, y), φ(x, y)} extracts the two-dimensional amplitude distribution A(x, y) and the two-dimensional phase distribution φ(x, y), and maps the two-dimensional phase distribution to the initial point cloud {P i (x i ,y i , z i )}:

[0102]

[0103] Among them, x i , yi is the two-dimensional coordinate, φ(x i ,y i ) is the phase information, k is the scalar conversion factor from phase to depth, and N is the total number of point clouds;

[0104] S222, for the initial point cloud {P i (x i ,y i , z i )} Apply the shape optimization function f opt (P) Perform three-dimensional phase correction to generate an optimized three-dimensional morphology point cloud {P′ i (x′ i , y′ i , z′ i )}:

[0105] P′ i (x′ i , y′ i , z′ i ) = f opt (Pi) = (x i +Δx,y i +Δy,z i +Δz);

[0106] Among them, Δx, Δy, Δz are based on the optimization function f opt The correction offset of

[0107] S223, the optimized three-dimensional morphology point cloud {P′ i (x′ i , y′ i , z′ i )} is converted into a three-dimensional phase target matrix D 3D ={P(x, y, z)}, where {P(x, y, z)} represents the phase distribution of the three-dimensional morphology information of the craft.

[0108] In this implementation, S23 specifically includes:

[0109] S231, for the three-dimensional phase target matrix D 3D = {P(x, y, z)} performs discrete Fourier transform to generate the frequency domain representation matrix F 3D ={F(u, V， w)}:

[0110]

[0111] Among them, F(u, V， w) represents the information of three-dimensional phase distribution in the frequency domain, and u, V, and w are the frequency domain coordinates;

[0112] S232, frequency domain representation matrix F 3D Perform two-dimensional projection processing to project the three-dimensional frequency domain information onto the plane frequency domain matrix F 2D ={F(u, v)} to retain the main information components in the frequency domain:

[0113]

[0114] Among them, F(u, v) represents two-dimensional frequency domain information;

[0115] S233, based on the light field coding function G(F 2D ) for the plane frequency domain matrix F 2D Perform phase encoding processing to generate the light field modulation pattern matrix T mod :

[0116] T mod (x,y)=arg[G(F 2D )];

[0117] Where arg represents the phase extraction operation, T mod (x, y) is the two-dimensional phase distribution of the light field modulation pattern matrix in spatial coordinates.

[0118] In this implementation, S4 specifically includes:

[0119] S41, filling the target printing area with a photosensitive resin material, and controlling the concentration of the photosensitive resin material to remain stable in the target area through a uniform distribution device;

[0120] S42, the light field modulation pattern matrix T mod (x, y) is loaded into the spatial light modulator, and after the coherent beam projection of the laser source, a holographic light field H(x, y, z) is generated:

[0121]

[0122] Wherein, K(x, y, z) represents the point spread function of light field propagation, and H(x, y, z) represents the holographic light field in the target printing area;

[0123] S43, superimposing the generated holographic light field H(x, y, z) with the composite light field of the multi-band laser source, and combining the laser frequency {f n}Form a composite light field L(x,y,z,t);

[0124] S44, under the action of the composite light field L(x, y, z, t), stimulating the multi-photon absorption mechanism in the photosensitive resin material, initiating a volume photopolymerization reaction of the photosensitive resin material through the multi-photon absorption, so that the resin material is cured in the composite light field focusing area to generate a three-dimensional structure;

[0125] S45, controlling the projection time of the composite light field and the laser intensity distribution to ensure that the polymerization reaction is limited to the target printing area, thereby forming the boundary of the target three-dimensional structure.

[0126] In this implementation, S43 specifically includes:

[0127] S431, inputting the generated holographic light field H(x, y, z) into a light field control device, controlling the phase distribution and light intensity distribution of the holographic light field in the target printing area, so that the light field energy is concentrated in the target printing area and matches the three-dimensional morphology information;

[0128] S432, setting the laser frequency combination of the multi-band laser source {f n}, generate laser intensity distribution I n (x,y,z):

[0129]

[0130] Where I0 is the initial laser intensity, α n is the attenuation coefficient, r(x,y,z) represents the propagation distance of the light field;

[0131] S433, laser intensity distribution of superimposed multi-band laser sources I n (x,y,z) and the holographic light field H(x,y,z) to generate a composite light field L(x,y,z,t):

[0132]

[0133] Among them, f n is the laser frequency, φ n is the phase delay, t is the time, and M is the total number of laser frequencies.

[0134] In this implementation, S44 specifically includes:

[0135] S441. Under the action of the composite light field L(x, y, z, t), the photosensitive molecules in the photosensitive resin material absorb multiple photon energies, stimulating the multi-photon absorption mechanism in the photosensitive resin material, stimulating it to a high energy state, triggering a chemical reaction of the molecular bonds, and the multi-photon absorption rate is:

[0136]

[0137] Among them, R abs (x,y,z) is the multiphoton absorption rate, σ abs is the absorption cross-section coefficient, k abs is the photon absorption order, I n (x, y, z) is the intensity distribution of the nth laser component at the target position, and M is the total number of laser frequencies;

[0138] S442, generating free radicals through multi-photon absorption, polymerizing the monomers in the photosensitive resin material into polymer chains, and the polymerization rate of the photopolymerization reaction is:

[0139] R poly (x,y,z)=η poly ·R abs (x,y,z);

[0140] Among them, R poly (x, y, z) is the polymerization rate, η poly is the polymerization efficiency coefficient, R abs (x, y, z) is the multiphoton absorption rate;

[0141] S443. Control the spatial distribution and projection time of the composite light field L(x, y, z, t) so that the polymerization reaction is limited to the target area. By adjusting the light field parameters, the spatial accuracy of the polymerization reaction is optimized to generate a three-dimensional structure.

[0142] In this implementation, S7 specifically includes:

[0143] S71. Scan the three-dimensional shape of the molded craftwork to obtain a point cloud data set D of the actual shape. actual = {Q a (x a ,y a ,z a )}, where Q a (x a ,y a ,z a ) represents the point coordinates of the actual printed surface;

[0144] S72, a three-dimensional shape data set D of the target craftwork target = {Q t (x t ,y t ,z t )} and compare it with the actual shape point cloud data set D actual For registration, the rigid transformation matrix M align Align the two:

[0145] Q′ a (x′ a ,y′ a ,z′ a )=M align Q a (x a ,y a ,z a );

[0146] Among them, Q′ a (x′ a ,y′ a ,z′ a ) is the aligned point cloud data, M align Contains rotation and translation parameters;

[0147] S73. Calculate the shape error ΔE(x, y, z) between the aligned point cloud data:

[0148]

[0149] Among them, ΔE(x, y, z) represents the Euclidean distance error between the target artifact and the formed artifact;

[0150] S74, inputting the shape error distribution ΔE(x, y, z) into the holographic phase modulation unit, optimizing the parameters of the holographic phase modulation algorithm, and adjusting the phase modulation distribution matrix and the light field projection parameters through an iterative algorithm;

[0151] S75. Update the holographic light field generation and projection control data according to the optimized phase modulation distribution matrix and projection parameters.

[0152] In this implementation manner, S74 specifically includes:

[0153] S741, input the shape error distribution ΔE(x, y, z) into the holographic phase modulation unit, and map it to a two-dimensional phase error matrix ΔΦ(x, y):

[0154] ΔΦ(x,y)=f map (ΔE(x,y,z));

[0155] Among them, f map is the error mapping function, ΔΦ(x,y) is the two-dimensional phase error distribution of the target printing area;

[0156] S742, based on the two-dimensional phase error matrix ΔΦ(x,y), optimize the phase modulation distribution matrix T through an iterative algorithm mod-opt (x,y):

[0157]

[0158] in, is the phase modulation matrix of the kth iteration, α is the step size factor, is the gradient distribution of phase error;

[0159] S743. Adjust the projection parameters of the holographic light field according to the optimized phase modulation distribution matrix, and perform simulation verification on the optimized phase modulation distribution matrix and the projection parameters of the holographic light field to verify whether the optimization effect meets the accuracy requirements. If not, return to step S742 for further iteration.

[0160] Embodiment 1:

[0161] In order to verify the feasibility of the present invention, the present invention is applied to the comprehensive scenario of cultural heritage reproduction and modern craft reproduction. The experiment is carried out in a professional craft design center, which needs to reproduce a batch of exquisite artworks with complex surfaces to meet exhibition needs and develop new modern crafts at the same time. The experimental site is located in the digital manufacturing laboratory of the center. The experimental time is from June 2023 to September 2023.

[0162] In this experiment, the limitations of traditional handicraft digitization technology are obvious, especially in the incomplete data collection of complex curved surfaces and defects in the joints between printed layers. The present invention introduces a digital 3D printing method for handicrafts based on holographic volumetric additive manufacturing technology, which provides a complete solution from data collection to printing through holographic phase modulation technology and multi-photon absorption mechanism.

[0163] In this scenario, the experimental team first holographically scans the crafts that need to be replicated to generate a holographic data file containing geometric information and surface texture information. These data are optimized and calculated through the holographic phase modulation unit to generate high-precision three-dimensional morphology information. Subsequently, the optimized data is loaded into the spatial light modulator, and the holographic light field is guided by a multi-band laser to achieve efficient molding of three-dimensional shapes in the photosensitive resin. For each craft, the team further uses error analysis technology to compare the molded crafts with the target model, and optimizes the holographic light field generation parameters based on the comparison results to ensure printing accuracy and consistency.

[0164] In order to verify the effect, the team designed a comparative experiment to evaluate the performance of traditional 3D printing technology and the present invention in terms of printing efficiency, surface smoothness and detail restoration. The results are shown in Table 1.

[0165] Table 1 Performance comparison between conventional technology and the present invention

[0166] index Test Method Traditional Technology The present invention Average printing time It takes time to print a single craft completely 5 hours 23 minutes 48 minutes Surface roughness(μm) Surface roughness tester measurement average value 17.3 3.2 Detail restoration rate High-resolution image comparison 85.2％ 98.7％ Interlayer bonding defects Scan defect ratio at joint 8.4％ No defects Material adaptability Support printing effects on different media Low high

[0167] It can be seen from the data in Table 1 that the printing time of the present invention is significantly shortened, and the printing time of each craftwork is only about 1 / 6 of that of the traditional technology. At the same time, the surface roughness is reduced to 3.2μm, and the detail restoration rate is increased to 98.7%, which can accurately reproduce complex curved surfaces and fine textures. In addition, the interlayer bonding defects common in traditional technologies are completely avoided in the present invention, and the material adaptability is greatly enhanced, supporting high-precision printing of scattering media and non-absorbent materials.

[0168] Take a complex dragon-shaped craftwork as an example. The curved surface texture of the craftwork is extremely complex. The traditional method takes 6 hours to complete and misses many detailed areas during scanning. Through the present invention, high-precision printing is completed in just 50 minutes, and the details of the dragon scale texture are fully preserved.

[0169] During the entire quarter of the replica project, the invention completed the digitization and printing of 45 complex crafts, with an overall error rate of less than 1%, while traditional technology reached 12% in similar projects. In addition, in the development of modern crafts, the high efficiency and low defect rate of the invention help designers to realize the printing of creative designs more quickly.

[0170] In summary, the present invention achieves full process optimization from digitization to printing of complex handicrafts through efficient data processing technology and intelligent holographic light field control. It significantly reduces printing time and error rate, improves detail restoration and surface quality, and provides innovative solutions for the field of handicraft digitization and manufacturing.

[0171] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A digital 3D printing method for handicrafts, characterized in that: The steps include: S1. Use a holographic scanning device to perform holographic scanning on the target craftwork, collect the geometric structure and surface texture data of the target craftwork by recording the light field phase and amplitude information, and generate a holographic data file containing complete three-dimensional geometric information; S2, inputting the holographic data file into the holographic phase modulation unit, performing phase modulation calculation on the three-dimensional data through the holographic phase modulation algorithm, generating a light field modulation pattern matrix with three-dimensional morphology information, and loading the holographic phase map into the spatial light modulator; S3, modulating the loaded light field modulation pattern matrix through a spatial light modulator, projecting the three-dimensional geometric information into the target printing area in the form of a dynamic light field, and reconstructing a holographic light field consistent with the geometric shape of the craftwork; S4, filling the target printing area with a photosensitive resin material, acting on the holographic light field through a multi-band laser source, and utilizing a multi-photon absorption mechanism to cause a volume photopolymerization reaction of the photosensitive resin in the light field reconstruction area to form a three-dimensional structure; S5. Adjust the projection time of the holographic light field and the light intensity distribution of the multi-band laser source to make the resin photopolymerization reaction uniform and accurate, so as to realize the one-time molding of the three-dimensional structure of the handicraft; S6. Process the formed three-dimensional crafts, including removing unreacted materials, surface smoothing and curing enhancement operations, to ensure the surface quality and overall stability of the printed crafts; S7. Use shape error analysis technology to analyze the three-dimensional morphology of the molded craftwork and the target craftwork, input the error analysis results into the holographic phase modulation unit, and optimize the holographic phase modulation algorithm and projection parameters.

2. A digital 3D printing method for handicrafts according to claim 1, characterized in that: The S2 specifically includes: S21, inputting the three-dimensional geometric information and surface texture data in the holographic data file into the holographic phase modulation unit, and defining the input data matrix D by extracting the light field amplitude and phase distribution of the holographic data file. input ={A(x, y), φ(x, y)}, where A(x, y) represents the amplitude distribution of the light field, and φ(x, y) represents the phase distribution of the light field; S22, based on the holographic phase modulation algorithm, the input data matrix D input Convert to a three-dimensional phase target matrix D 3D ={P(x, y, z)}, where {P(x, y, z)} represents the phase distribution of the three-dimensional morphology information of the craft; S23, for the three-dimensional phase target matrix D 3D Perform light field encoding processing and generate the light field modulation pattern matrix T through the digital holographic algorithm mod =G(D 3D ), where G represents a light field encoding function, which is used to convert three-dimensional shape information into a two-dimensional phase distribution required for spatial light modulation; S24, the light field modulation pattern matrix T mod Loading to the spatial light modulator, adjusting the phase modulation parameters of the light modulator, so that the modulated dynamic light field can restore the three-dimensional shape information of the target; S25, real-time interference analysis of the loaded light field modulation pattern T mod Calibration is performed to verify the matching degree between the phase distribution and amplitude distribution of the light field modulation pattern and the target three-dimensional morphology information.

3. A digital 3D printing method for handicrafts according to claim 2, characterized in that: The S22 specifically includes: S221, based on the input data matrix D input = {A(x, y), φ(x, y)} extracts the two-dimensional amplitude distribution A(x, y) and the two-dimensional phase distribution φ(x, y), and maps the two-dimensional phase distribution to the initial point cloud {P i (x i ,y i , z i )}: Among them, x i ,y i is a two-dimensional coordinate, φ(x i ,y i ) is the phase information, k is the scalar conversion factor from phase to depth, and N is the total number of point clouds; S222, for the initial point cloud {P i (x i ,y i , z i )} Apply the shape optimization function f opt (P) Perform three-dimensional phase correction to generate an optimized three-dimensional morphology point cloud {P′ i (x′ i , y′ i , z′ i )}: P′ i (x′ i ,y′ i ,z′ i )=f opt (P i )=(x i +Δx,y i +Δy,z i +Δz); Among them, Δx, Δy, Δz are based on the optimization function f opt The correction offset of S223, the optimized three-dimensional morphology point cloud {P′ i (x′ i , y′ i , z′ i )} is converted into a three-dimensional phase target matrix D 3D ={P(x, y, z)}, where {P(x, y, z)} represents the phase distribution of the three-dimensional morphology information of the craft.

4. A digital 3D printing method for handicrafts according to claim 1, characterized in that: The S23 specifically includes: S231, for the three-dimensional phase target matrix D 3D = {P(x, y, z)} performs discrete Fourier transform to generate the frequency domain representation matrix F 3D ={F(u, v, w)}: Wherein, F(u, v, w) represents the information of three-dimensional phase distribution in the frequency domain, and u, v, w are the frequency domain coordinates; S232, frequency domain representation matrix F 3D Perform two-dimensional projection processing to project the three-dimensional frequency domain information onto the plane frequency domain matrix F 2D ={F(u, v)} to retain the main information components in the frequency domain: Among them, F(u, v) represents two-dimensional frequency domain information; S233, based on the light field coding function G(F 2D ) for the plane frequency domain matrix F 2D Perform phase encoding processing to generate the light field modulation pattern matrix T mod : T mod (x,y)=arg[G(F 2D )]: Where arg represents the phase extraction operation, T mod (x, y) is the two-dimensional phase distribution of the light field modulation pattern matrix in spatial coordinates.

5. A digital 3D printing method for handicrafts according to claim 1, characterized in that: The S4 specifically includes: S41, filling the target printing area with a photosensitive resin material, and controlling the concentration of the photosensitive resin material to remain stable in the target area through a uniform distribution device; S42, the light field modulation pattern matrix T mod (x, y) is loaded into the spatial light modulator, and after the coherent beam projection of the laser source, a holographic light field H(x, y, z) is generated: Wherein, K(x, y, z) represents the point spread function of light field propagation, and H(x, y, z) represents the holographic light field in the target printing area; S43, superimposing the generated holographic light field H(x, y, z) with the composite light field of the multi-band laser source, and combining the laser frequency {f n }Form a composite light field L(x, y, z, t); S44, under the action of the composite light field L(x, y, z, t), stimulating the multi-photon absorption mechanism in the photosensitive resin material, initiating a volume photopolymerization reaction of the photosensitive resin material through the multi-photon absorption, so that the resin material is cured in the composite light field focusing area to generate a three-dimensional structure; S45, controlling the projection time of the composite light field and the laser intensity distribution to ensure that the polymerization reaction is limited to the target printing area, thereby forming the boundary of the target three-dimensional structure.

6. A digital 3D printing method for handicrafts according to claim 4, characterized in that: The S43 specifically includes: S431, inputting the generated holographic light field H(x, y, z) into a light field control device, controlling the phase distribution and light intensity distribution of the holographic light field in the target printing area, so that the light field energy is concentrated in the target printing area and matches the three-dimensional morphology information; S432, setting the laser frequency combination of the multi-band laser source {f n }, generate laser intensity distribution I n (x, y, z): Where I0 is the initial laser intensity, α n is the attenuation coefficient, r(x, y, z) represents the propagation distance of the light field; S433, laser intensity distribution of superimposed multi-band laser sources I n (x, y, z) and the holographic light field H(x, y, z) to generate a composite light field L(x, y, z, t): Among them, f n is the laser frequency, φ n is the phase delay, t is the time, and M is the total number of laser frequencies.

7. A digital 3D printing method for handicrafts according to claim 4, characterized in that: The S44 specifically includes: S441. Under the action of the composite light field L(x, y, z, t), the photosensitive molecules in the photosensitive resin material absorb multiple photon energies, stimulating the multi-photon absorption mechanism in the photosensitive resin material, stimulating it to a high energy state, triggering a chemical reaction of the molecular bonds, and the multi-photon absorption rate is: Among them, R abs (x, y, z) is the multiphoton absorption rate, σ abs is the absorption cross-section coefficient, k abs is the photon absorption order, I n (x, y, z) is the intensity distribution of the nth laser component at the target position, and M is the total number of laser frequencies; S442, generating free radicals through multi-photon absorption, polymerizing the monomers in the photosensitive resin material into polymer chains, and the polymerization rate of the photopolymerization reaction is: R poly (x,y,z)=η poly ·R abs (x, y, z)? Among them, R poly (x, y, z) is the polymerization rate, η poly is the polymerization efficiency coefficient, R abs (x, y, z) is the multiphoton absorption rate; S443. Control the spatial distribution and projection time of the composite light field L (x, y, z, t) so that the polymerization reaction is limited to the target area. By adjusting the light field parameters, the spatial accuracy of the polymerization reaction is optimized to generate a three-dimensional structure.

8. A digital 3D printing method for handicrafts according to claim 1, characterized in that: The S7 specifically includes: S71. Scan the three-dimensional shape of the molded craftwork to obtain a point cloud data set D of the actual shape. actual = {Q a (x a ,y a , z a )}, where Q a (x a ,y a , z a ) represents the point coordinates of the actual printed surface; S72, a three-dimensional shape data set D of the target craftwork target = {Q t (x t ,y t , z t )} and compare it with the actual shape point cloud data set D actual For registration, the rigid transformation matrix M align Align the two: Q′ a (x′ a ,y′ a ,z′ a )=M align ·Q a (x a ,y a ,z a ); Among them, Q′ a (x′ a , y′ a , z′ a ) is the aligned point cloud data, M align Contains rotation and translation parameters; S73. Calculate the shape error ΔE(x, y, z) between the aligned point cloud data: Wherein, ΔE(x, y, z) represents the Euclidean distance error between the target artifact and the formed artifact; S74, inputting the shape error distribution ΔE(x, y, z) into the holographic phase modulation unit, optimizing the parameters of the holographic phase modulation algorithm, and adjusting the phase modulation distribution matrix and the light field projection parameters through an iterative algorithm; S75. Update the holographic light field generation and projection control data according to the optimized phase modulation distribution matrix and projection parameters.

9. A digital 3D printing method for handicrafts according to claim 7, characterized in that: The S74 specifically includes: S741, input the shape error distribution ΔE(x, y, z) into the holographic phase modulation unit, and map it to a two-dimensional phase error matrix ΔΦ(x, y): ΔΦ(x,y)=f map (ΔE(x,y,z)); Among them, f map is the error mapping function, ΔΦ(x, y) is the two-dimensional phase error distribution of the target printing area; S742, based on the two-dimensional phase error matrix ΔΦ(x, y), optimize the phase modulation distribution matrix T by an iterative algorithm mod-opt (x, y): in, is the phase modulation matrix of the kth iteration, α is the step size factor, is the gradient distribution of phase error; S743. Adjust the projection parameters of the holographic light field according to the optimized phase modulation distribution matrix, and perform simulation verification on the optimized phase modulation distribution matrix and the projection parameters of the holographic light field to verify whether the optimization effect meets the accuracy requirements. If not, return to step S742 for further iteration.

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