CN105259664B - A kind of optical field imaging printing equipment and the film with three-dimensional floating image - Google Patents

Abstract

The present invention proposes a light field imaging printing device and a microlens film with a three-dimensional floating image prepared by the light field imaging printing device, using a scanning galvanometer system to scan on the lens surface, combined with the change of three-dimensional coordinates in space to realize four-dimensional Light field data printing. The light field imaging printing device includes a light source, a scanning galvanometer system, a lens, a diffusion sheet, a converging lens group, and a microlens recording material. The light passes through the scanning galvanometer system, lens, diffusion sheet, and converging lens group in sequence, and outputs a transient dynamic focus spot , to obtain the radiation light field of the voxel, and then record the instantaneous information of the radiation light field of the voxel by the microlens recording material. The present invention can realize a more realistic three-dimensional dynamic image, realize multiple floating images with different characteristics by controlling different variable values, and ensure the realization of imaging effects such as multi-angle variable images.

Description

A light field imaging printing device and a thin film with three-dimensional floating images

technical field

The invention relates to the field of light field imaging, in particular to a light field imaging printing device and a film with three-dimensional floating images.

Background technique

The real three-dimensional object can be observed by people because the object emits light energy into the space. The object can be regarded as a collection of many point light sources that emit light, and each point light source is called a voxel of the object. When people observe a three-dimensional object, they actually obtain the spatial position information of each voxel of the object and the direction information of the light emitted by each voxel. Based on the above principles, the light field imaging theory believes that to express a three-dimensional object information on a two-dimensional plane, at least four independent variables are required, namely the three-dimensional coordinate variable x-y-z and the direction variable θ, and the light field is defined as all the four-parameter rays in space A collection of radiance functions L(x, y, z, θ).

Light field imaging technology can be traced back to Integral Photography (IP) proposed by French scientist Lippmann in 1908. This method uses recording materials covered with microlenses or pinhole arrays to obtain light field information of three-dimensional objects. The light emitted by the real object passes through the microlens array into a reduced real image and exposes the photosensitive layer of the photographic negative. Due to the different spatial positions, each microlens images the object from a different perspective, so the final image of the photographic negative is The image is a composite image formed by each microlens. After the photographic negative is developed, the composite image on the negative is viewed through the microlens array. According to the principle of light reversibility, the observer will see the three-dimensional reproduction of the shot scene, and the visual effect of the three-dimensional reproduction seems to be suspended on the negative. Since the microlens material records objects from different directions, it records object images with parallax. When reappearing, if the observer changes the orientation, the observation angle of the two eyes will undergo continuous subtle changes by the microlens, visually forming a spatially dynamic three-dimensional floating imaging effect.

The laser printing technology based on the principle of light field imaging uses the focal point of the converging laser to simulate the radiation light field of the pixel of the three-dimensional object, and obtains the information of the light field by the microlens array film material. Using optical, mechanical, and electrical devices to control converging light rays at different incident angles and different focusing heights, input text, two-dimensional or three-dimensional images, and reproduce objects with different dynamic depths of field. This type of technology mainly includes the design and manufacture of microlens film recording materials and the acquisition of simulated point light fields.

As for the microlens recording material, US Pat. No. 2,326,634 discloses a method of partially embedding transparent microspheres into a polymeric material binder layer, and then plating an aluminum film with a thickness of about 80 nm on the back of the polymeric material. This type of material uses transparent microspheres to focus the incident light field, and the energy of the focused light spot reaches the damage threshold of the aluminum film to ablate the aluminum film, destroying the reflectivity of the material there, which is different from the reflectivity of the background aluminum layer. , resulting in a difference in contrast, that is, pixels are generated. In order to obtain a color image, a multilayer thin film material can also be used instead of a single aluminum layer. When the multilayer film absorbs different light energies and is ablated into a relief structure with uneven thickness, a color image will be presented based on the principle of thin film interference. . As described in U.S. Patent US3801183, use cryolite/zinc sulfide (Na3 AlF6/ZnS) double-layer film structure, or chromium/polymer/silicon dioxide/aluminum multi-layer film. For more film structure details, please refer to patent CN200880106663 .4. The semi-bare microspheres of the above materials are easily damaged, resulting in a decrease in the quality of the reproduced image. Chinese patent CN201180053337.3 provides a structure for protecting the microlens, which completely immerses the transparent microspheres in the adhesive layer, and then glues them The mixture layer is coated with a transparent material layer of about 200um. This transparent material layer can not only prevent the microspheres from leaving their positions, but also obtain excellent durability such as friction resistance and impact resistance. Moreover, the transparent material layer can be used as a whole material Provides a superb glossy look.

For the acquisition of simulated point light fields, Chinese patent document CN200880106663.4 describes various schemes for obtaining light fields. Option 1 is to reduce the diameter of the parallel laser light source to about 1mm through the optical system, irradiate it on the ceramic beads of about 5mm, and use the scattering effect of the rough ceramic beads to obtain the diffused light field, which matches the x-y-z space of the recording material Coordinate movement to record the light field data of a three-dimensional object. The second option is to use a lens to converge parallel laser beams to generate a point light field. In this method, the light spot is enlarged by the diffuser, the expanded beam is obtained by the collimation system, and the convergence of the convex lens or the diffusion function of the concave lens is used to generate a point light field with a focusing effect, which represents a voxel of the object to be printed. By moving the x-y platform where the recording material is located to change the relative spatial position of the voxel, a two-dimensional graphic information can be directly written, and by changing the height of the converging lens, the spatial position of the voxel with different depth information can be obtained, thereby , to achieve floating graphics by scanning and printing layer by layer. The third solution is to use laser beams to irradiate the surface of the microlens array, refract the beams by microlenses with large numerical apertures, and then collect the divergent beams by convex lenses to obtain a converging point light field. At the same time, the light spot is moved by the scanning of the galvanometer, thereby directly printing image information on the recording material.

Chinese patent document CN201310291009.8 uses a galvanometer to scan on a converging lens, uses the refraction of the converging lens to obtain light rays with different incident angles, places a microlens array with a large numerical aperture near the focal plane of the lens, and uses the microlens to deflect the beam to obtain diffusion point light field. The point light source is always suspended above the surface of the recording material. In order to obtain a sinking converging point light field, the patent points out that a convex lens can be placed between the microlens array and the recording material to collect the diffused light energy and focus it on Underneath the recording material, resulting in sunken print imaging. Due to the high scanning frequency of the galvanometer, the lens can focus each scanning light to the same point in a very short time, and a dynamic converging spot can be generated instantaneously at the focal plane of the lens, compared with the single beam of patent CN200880106663.4 Convergent imaging can increase the field of view of the reproduced image, and the image has a strong sense of dynamics.

Chinese patent document CN200880117941.6 discloses a technology that can use a microlens recording material master mold for mass replication. This method still adopts the optical system of lens converging parallel light to obtain the converging light field, and the recording layer of the master mold material mentioned in the article is no longer the above-mentioned aluminum or multi-layer film, but is coated with a photopolymerizable material layer, the material For the femtosecond laser light source, the layer can absorb single-photon, two-photon or even multi-photon, so that the local physical and chemical properties of the polymer material will change. For example, the material with this local property change cannot be dissolved by organic solvents such as ethanol without The part of the material that absorbs photons can be dissolved, so that the dissolved material will have a relief structure, thereby recording the information of the image. This relief structure is cured in a series to make a master mold with certain resistance to mechanical deformation. Using mature micro-replication technology, such as roll-to-roll embossing, mass production can be realized.

In the above-mentioned patents, the methods of making thin films with three-dimensional floating images are different, especially the acquisition devices for simulating point light fields are different, resulting in different viewing angles and dynamic observation ranges of floating images reproduced by thin films. Although each has its own advantages, But the shortcomings are also obvious. As described in Solution 1 of the patent CN200880106663.4, the obtained voxel size is at least the diameter of the laser beam, resulting in low resolution of the imaging quality during reproduction. As mentioned in Scheme 2, since the light intensity distribution of the laser beam belongs to Gaussian distribution, this method of expanding and focusing the single beam laser makes the light energy density collected on the surface of the recording material uneven, and it is difficult to control the position of each point. When the modified energy threshold of the recording material is reached, the light energy cannot be effectively utilized, resulting in a small numerical aperture of the obtained conical point light field, which affects the viewing angle of view during reproduction. Although the image has a sense of floating or sinking depth of field, due to the small field of view, the dynamic sense is weak, and the system does not have a variable "azimuth" variable, and does not have the ability to input different graphics under different field of view , the printing mode is single. Solution 3 requires accurate alignment between the scanning spot and the microlens. Otherwise, when the laser beam moves to the boundary of the two microlenses, its refraction function is weakened, and the beam may be divided into two, which affects the imaging structure. When the spot scans to the edge, Part of the light will deviate from the collection range of the lens, reducing energy utilization, reducing the numerical aperture and field of view of the system, because the solution only relies on the scanning of the galvanometer to project the pixel position of the input image, because the final light is no longer along the galvanometer The outgoing direction propagates, but passes through the deflection of the optical system, and the imaging point deviates from the preset position, resulting in the final image no longer being an ideal image, such as distortion. At the same time, in the process of printing multi-view graphics, the system first provides a converging light field with an incident angle, keeps this incident angle, and realizes the input of a view by moving the x-y platform, and then provides another incident angle by the system. Converging the light field and repeatedly moving the x-y platform to input another viewing angle graphics is not only inefficient, but also has the problem of precise alignment of the light rays of each viewing angle with the same position. The method adopted in the patent CN201310291009.8 finally obtains the converging light field through the refraction of the microlens array, which also has the disadvantages of the above-mentioned patents. At the same time, because the lens only focuses in one-dimensional direction, other azimuth angle information is lost, so The presented image only has a sense of motion in one-dimensional direction. When inputting multi-view images in the scheme, the optical path needs to be calibrated first to obtain the desired viewing angle, and then input the viewing angle map, and then recalibrate the optical path of another viewing angle, and then input another picture, and repeat this process. program until outputting all perspective maps. Obviously, such a solution is not only inefficient, but also needs to input multiple perspective images at the same position, and each operation needs to be accurately aligned to the position, which increases the complexity.

The binocular vision system has the function of observing the same object from two directions at the same time. The objects are respectively projected two-dimensionally on the retina, and the brain synthesizes the two parallax projection images to produce a three-dimensional effect. The light field radiated by each surface point of a real three-dimensional object has the characteristics of conical diffusion. The angle α of the cone radiation can range from 0-360°, and the larger the angle, it means that the visual field of this object point can be observed The larger the field angle. The laser printing light field imaging system uses converging lasers to synthesize the light field of a three-dimensional object, and its focal point corresponds to a voxel of the object. The characteristics of the simulated voxel light field obtained in the previous scheme are different. The effect is also different. For example, different numerical apertures lead to different angles of view for dynamically observing images. The larger the numerical aperture, the larger the field of view, and the stronger the sense of dynamics. Therefore, how to synthesize a voxel light field with a large numerical aperture is a problem to be solved in this patent.

Of course, how to record the synthesized light field information is another focus of this profession. Use a two-dimensional plane to record a three-dimensional object. When reproducing it, it is hoped that the object can be observed continuously from different angles as if it were on the scene. This requires materials that can record the cone-shaped radiation light field emitted by each point of the object to the greatest extent. Furthermore, since the amount of information of a three-dimensional object is greater than that of a two-dimensional object, people hope that the same material area can record more abundant information, that is, the material is required to have a spatial multiplexing function, so that observers can observe different objects from different directions. object image. The laser light field imaging printing system based on the microlens array recording material meets the technical conditions of simulation and recording at the same time, and can directly reproduce the image of a three-dimensional object after printing.

As mentioned above, the light field imaging technology needs four independent variables to express a three-dimensional object in space, and different imaging effects can be realized according to the value range of the variables used. There are only three independent variables in the light field imaging technology described in literature, and the other dimension is constant. As described in the CN200880106663.4 patent, it is a space coordinate x-y-z variable system, and the direction angle variable θ is a constant, so the system can obtain 3D depth-of-field images, but cannot realize the space multiplexing function, and due to the reasons of the previous analysis, the 3D dynamic sense is weak . However, the patent CN201310291009.8 is a (x, y, z, θ) variable system, and z is a constant. Therefore, different two-dimensional graphics can be input under different viewing angles, but three-dimensional objects cannot be printed.

Therefore, the industry urgently needs a thin film capable of realizing more realistic three-dimensional dynamic images and a light field imaging printing device with four-dimensional variables, which can realize floating images with various characteristics by controlling different variable values. It is ensured that imaging effects such as multi-view image change can be achieved, and a more realistic three-dimensional observation experience of objects can be obtained. For example, to achieve 360° surrounding floating images and more intense dynamic effects. Different images can also be printed from different orientation angles to prepare a three-dimensional image film with spatial multiplexing.

Contents of the invention

In view of this, the present invention proposes a four-dimensional variable light field imaging printing device and a microlens film with a three-dimensional floating image prepared by the four-dimensional variable light field imaging printing device.

The four-dimensional variable light field imaging printing device includes a light source, a scanning galvanometer system, a converging optical component, a microlens recording material, and an x-y-z three-axis moving platform, wherein the converging optical component includes a controllable rotating cylinder lens, the recording material is placed on the moving platform, and the light source The scanning galvanometer is scanned on the arc surface of the controllable rotating cylindrical lens, and finally a converging light field with a large numerical aperture is formed. The converging light field is focused to the recording layer of the thin film material through each microlens, and the focused energy makes the recording layer Modified to provide a pixel point, moving the x-y-z platform to change the spatial position of the microlens recording material, then the converging light field can form a plurality of pixel points on the recording layer behind each microlens, and these pixels constitute the rear surface of each microlens When the sub-images are reproduced, each microlens will refract the sub-images associated with it to space imaging, and jointly synthesize the floating image. The sub-images correspond to different viewing angle ranges, so the synthetic image can be observed from different viewing angles of the film, and as the observer moves, the viewed synthetic image has a dynamic effect.

The microlens film is prepared by the above-mentioned four-dimensional variable light field imaging printing device, which records the light field information of one or more objects, and can reproduce images suspended or sunk relative to the surface of the material, which are imaged by the microlens Synthetic images composed of magnified images formed by thin film materials, these suspended or sinking synthetic images are referred to as floating images. The floating image can be a two-dimensional image or a three-dimensional image, which can be black and white or colored. The floating image appears to be a three-dimensional depth-of-field image appearing above, on a plane or below the film material, or it can appear from a A three-dimensional image in which the depth changes continuously to another depth. The floating image has a viewing angle change property, which can be seen by the observer with the naked eye, and can change as the observer moves. The image reproduced by the microlens film material in the present invention not only has a large viewing angle and a strong image dynamic sense, but also has the characteristics of plane domain orientation, that is, a reproduced image can be dynamically observed in a certain orientation plane, and In another orientation plane, another different image can be reproduced at the same position. Different orientation planes are characterized by orientation angle θ, whose value is 0-360° and can be continuously selected.

In the present invention, various floating images with different characteristics can be realized by controlling different variable values. It is ensured that imaging effects such as multi-view image change can be achieved, and a more realistic three-dimensional observation experience of objects can be obtained. For example, to achieve 360° surrounding floating images and more intense dynamic effects. Different images can also be printed from different orientation angles to prepare a three-dimensional image film with spatial multiplexing.

A light field imaging printing device proposed according to the object of the present invention includes a light source, a scanning galvanometer system, a lens, a diffusion sheet, a converging lens group and a microlens recording material, and the scanning galvanometer system includes a galvanometer and a flat-field focusing lens, the lens is placed at the focal plane of the flat-field focusing lens, the diffuser is placed on the focal plane of the lens, the diffuser maintains an adjustable distance from the upper end of the converging lens group, the light source emits laser light, and the light rays are sequentially Through the scanning galvanometer system, lens, diffusion sheet and converging lens group, the instantaneous dynamic focus spot is output to obtain the radiation light field of the voxel, and then the information of the instantaneous radiation light field of the voxel is recorded by the microlens recording material.

Preferably, the microlens recording material includes a microlens array and a photosensitive layer located below the microlens array, the microlens array is an array composed of lenses with a clear aperture and a relief depth of micron, the light The sensitive layer is an irreversible optically variable material.

Preferably, the light source emits laser light, emits light through the scanning galvanometer system, and performs linear scanning on the surface of the lens to form a scanning light cluster. After passing through the lens, the scanning light cluster converges on the surface of the diffusion sheet and is scattered. The above-mentioned converging lens group collects and converges the light beams.

Preferably, when printing a three-dimensional object, the x-y-z platform where the microlens recording material is located is moved to obtain voxels at different spatial positions.

Preferably, the voxel radiation light field is controlled by four independent parameters, including three-dimensional space coordinate variables and lens orientation angle variables, and the variables can be freely combined to reduce the four-dimensional variables to three-dimensional or two-dimensional.

Preferably, the z-axis height of the microlens recording material and the orientation angle of the fixed lens are fixed, the platform where the microlens recording material is located only moves in the x-y direction, and the four-dimensional voxel light field expression is reduced to two dimensions, thus Print suspended or sunken two-dimensional light field graphics with multiple viewing angles or continuously changing viewing angles, and use the galvanometer scanning system to directly output a macro pixel, which contains many sub-pixels with different viewing angles, each sub-pixel corresponds to The pixels to be input to the multi-view graphics.

Preferably, the lens is selected from one of a cylindrical lens, a circularly symmetrical spherical lens, an aspheric lens with better focusing ability and a numerical aperture matching the cylindrical lens, and a combined lens with aberration correction.

Preferably, the lens is a cylindrical lens, and the numerical aperture of the cylindrical lens is between 0.3 and 0.95. It focuses the incident light in one dimension, and directly transmits the light in the other dimension. The beam that continues to propagate from the converging point spreads in a fan-shaped area .

Preferably, the cylindrical lens rotates around the Z-axis of its own geometric center, and the rotation angle of the cylindrical lens determines the orientation angle of the radiation light field in the fan-shaped area. When a certain orientation angle is used to print the three-dimensional light field data, the observer The image can only be observed in the fan-shaped plane of this orientation angle, and when it deviates from this orientation angle, the image disappears or the image in the deviated orientation plane can be observed.

Preferably, the lens is a spherical lens, the scanning galvanometer system linearly scans along the horizontal axis of symmetry of the spherical lens, and the output end of the converging lens group obtains a fan-shaped area volume pixel radiation light field.

The present invention also proposes a thin film with a three-dimensional floating image, which is prepared by the light field imaging printing device according to any one of claims 1-9, and is characterized in that: the light field information of one or more objects is recorded, which can be Reproduce a floating image suspended or sunk relative to the surface of the film, the floating image is composed of multiple sub-images with different viewing angles, and can be observed from different spatial viewing angles.

Preferably, the images observed in one orientation plane are multi-view images or multiple different images of the same object, and when deviating from the orientation plane, the images disappear or the deviated images in the orientation plane are observed.

Preferably, the floating image is a two-dimensional image or a three-dimensional image. When it is a three-dimensional image, the floating image is a three-dimensional depth-of-field image that appears above the film, on the plane of the film or below it, or a three-dimensional image that continuously changes from one depth to another. image.

Compared with the prior art, the present invention has the following technical advantages:

(1) It is proposed to use the four-dimensional light field parameters to realize the printout of 3D object data, and use the four-dimensional variable parameters to quantitatively describe all the light energy radiated by the object, that is, the light field can be expressed quantitatively, and the understanding of the light field from different angles can be understood It can be represented by different four-dimensional parameters. For example, if a ray intersects two parallel planes, the positions of the two intersection points are four variables. Three space coordinate variables and one-dimensional rotation angle variables can also be used to represent light field data information. However, the existing integrated imaging theory does not care about which parameters control the light field information captured by the microlens array material. However, in the present invention, the printing system using converging lasers to simulate the light field of the pixel of the object, the radiation light field can be precisely controlled by parameters, and has more practical value.

(2) The present invention can provide more abundant printing modes. For the four-dimensional variable light field imaging printing device, some of the parameters can be fixed as fixed values, or some of the parameters can be taken as limited discrete values. Highly dynamic 2D or 3D graphics. Moreover, from the expected graphics to reproduce the results, and reversely consider to set the printing parameters of the system, the thinking is clear and not easy to be confused. What is even more commendable is that since the cylindrical lens only focuses in one dimension, when the orientation angle of the cylindrical lens is set to some discrete value, different graphic information can be input respectively to realize multiple utilization of the same space of materials. The spatial reuse function of materials is not given in the existing technical solutions.

(3) The present invention can efficiently realize light field data printing, because the macropixel light field at a certain spatial position is essentially composed of many sub-pixel light fields with different incident angles of view scanned by the galvanometer in one cycle, and these sub-pixel light fields The field represents the pixel information at the same position of multiple images with different viewing angles, and due to the high-frequency scanning of the galvanometer, the input and recording of the sub-pixel set can be realized in a very short time, and the macro-pixels at the next position can be sequentially Light field input and recording can complete the printing of multi-view graphics. Since the galvanometer can be used for high-frequency continuous scanning, the invention can also efficiently input graphics with continuous changes in viewing angles. The same effect cannot be achieved in the prior art .

(4) The imaging field angle in the present invention is large and the dynamic sense is strong. Because the light intensity of the laser beam obeys the Gaussian distribution, and the energy is dense in the middle and sparse at the edge, after the Gaussian beam passes through the optical system of the device of the present invention, the energy distribution of the light field reaching the surface of the microlens recording material is still not uniform enough. Due to the limitation of the energy threshold of the material, not all All light energy can modify the material, thereby reducing the effective numerical aperture of the converging light field, thereby reducing the viewing angle and reducing the dynamic feeling when observing and reproducing graphics. However, in the present invention, the vibrating mirror is used to scan, so that the incident light energy distribution of different viewing angles behind the lens group is evenly distributed. The macro pixel obtained by light combination has the characteristics of large field of view and high dynamics. The geometric size of this macro pixel depends on the scanning distance of the vibrating mirror on the surface of the cylindrical lens, the numerical aperture of the cylindrical lens and the design of the optical path structure. The larger the numerical aperture, the closer to the cylindrical lens. The focal length of the lens, the smaller the macro pixel size, the clearer the reproduced graphics.

(5) The floating image reproduced by the microlens film can be synthesized from multiple sub-images with different viewing angles. The composite floating image can be observed from different spatial viewing angles. The image observed in a certain orientation plane can be a multi-view image of the same object. , can also be multiple different images. When deviating from the orientation plane, the image disappears, or an image in the deviating orientation plane is observed.

(6) A cylindrical lens with a large numerical aperture can rotate around its own optical axis. The rotation angle of the cylindrical lens determines the orientation angle during observation, that is, the rotation angle of the cylindrical lens provides an independent variable θ of the four-dimensional light field.

(7) The laser beam is scanned on the arc surface of the cylindrical lens to obtain the instantaneous dynamic incident light field of the volume pixel in the fan-shaped area. The arc surface of the cylindrical lens can also be designed as other symmetrical quadric surfaces with one-dimensional focusing. Cylindrical lens 4 can be replaced by a spherical lens with circular symmetry, or an aspheric lens with better focusing ability and numerical aperture matching the cylindrical lens, or a combination lens with aberration correction. When the scanning galvanometer system is symmetrical along the level of the spherical lens When scanning linearly in the axial direction, the output end of the converging lens group can also obtain the fan-shaped volume pixel light field, and control the light trajectory to scan along the horizontal symmetry axis of different orientations, so the printing mode in the present invention can be realized without mechanical rotation.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. Those skilled in the art can also obtain other drawings based on these drawings without creative work.

Figure 1 is a side view of a microlens recording material

Figure 2 is a cross-sectional view of a microlens recording material

Figure 3 is a schematic diagram of recording object light field information on a microlens recording material

Figure 4 is a schematic diagram of a microlens film reproducing a floating 3D image of an object by reflecting ambient light

Figure 5 is a schematic diagram of the calibration direction of the spatial coordinate system and the rotatable cylindrical lens of the independent parameters in the light field imaging printing device

Figure 6 is a schematic diagram of a light field imaging printing device

Fig. 7 is a schematic diagram of multiple viewing angles printed by the light field imaging printing device

Fig. 8 is a partially enlarged schematic diagram of printing multiple perspective views by the light field imaging printing device in Fig. 7

Figure 9 is a schematic diagram of microlens film multi-view observation

Figure 10 is a schematic diagram of the characteristics of a microlens film with a three-dimensional floating image, that is, a schematic diagram of different objects observed under different orientation angles of the microlens film

Figure 11 is a schematic diagram of a three-dimensional floating object in a 360° surrounding dynamic observation film

Figure 12 is a schematic diagram of macro pixels composed of sub-pixels

Fig. 13 is a schematic diagram of replacing the cylindrical lens with a circular symmetric focusing lens in the light field imaging printing device

Figure 14 is a schematic diagram of the scanning trajectory line orientation of the scanning galvanometer system on the circular symmetric focusing lens

Figure 15 is a schematic diagram of the microlens film reproduction dynamic line

Detailed ways

As mentioned in the background technology, in the prior art, the three-dimensional floating image film produced has the disadvantages of low imaging quality resolution during reproduction, low light energy utilization rate, single printing mode, and high complexity. Therefore, the present invention proposes The light field imaging and printing device with four-dimensional variables can prepare films with more realistic three-dimensional dynamic images. By controlling different variable values, a variety of floating images with different characteristics can be realized, ensuring that imaging effects such as multi-view images can be achieved. , and can obtain a more realistic three-dimensional observation experience of objects, and can also print different images from different orientation angles to prepare a three-dimensional image film with spatial multiplexing.

Next, the specific technical solution of the present invention will be introduced in detail.

Please refer to FIGS. 1 to 2 together, which are a side view and a cross-sectional view of the microlens recording material 1 respectively. The microlens recording material 1 includes a microlens array 11 covering the top and a photosensitive layer 12 below the microlens array 11. The lens array 11 is an array composed of lenses with a clear aperture and a relief depth of micron. It not only has the basic functions of focusing and imaging of traditional lenses, but also has the characteristics of small unit size and high integration. Usually, each lens The period is between 20μm-200μm. The microlenses themselves can have different forms, such as circular plano-convex lenslets, circular biconvex lenslets, microspheres or bead-shaped lenslets. Materials for making microlenses include glass, polymers, minerals, crystals, semiconductors, and combinations of these and other materials.

The light-sensitive layer 12 is an irreversible light-changing material, and when the light exceeds its surface threshold energy, the material will undergo changes including color or properties. These materials include metals, metal oxides, polymers, semiconductor materials, and multilayer films composed of these materials. For example, the heat-absorbing evaporation of aluminum-coated materials or the blackening of the surface of some polymer materials under laser irradiation will lead to material modification and contrast changes with the original substrate material, that is, pixels will be generated. When a laser beam passes through the microlens array 11 to form some images on the photosensitive layer 12 , the microlens array 11 slightly changes the pixel light, making the reproduced pattern appear to have a dynamic effect of floating or sinking.

The light source 2 provides laser irradiation, and the light source 2 is a laser with high peak power such as a fiber laser or a semiconductor-pumped solid-state laser or an excimer laser, a rubidium-doped yttrium aluminum garnet (Nd:YAG for short) laser, and the like. The patterns are formed by ablating the recording layer with these high peak power radiation sources. When the photosensitive layer 12 is imaged by a non-ablative method such as photochromic method, laser light sources with low peak power such as laser diodes, ion lasers, and gas lasers can be used. Using the light field imaging printing device of the present invention, the parallel laser beams are modulated into focused beams that diffuse in different directions or converge in the same direction, so as to simulate the voxel radiation characteristics of real objects.

Please refer to FIG. 3 , which is a schematic diagram of recording object light field information on a microlens recording material. In the recording stage, as shown in Figure 3, a voxel O of the stereo model is simulated by a divergent laser spot, and the spatial light field information radiated by this pixel is captured and recorded by the microlens array material, because the three-dimensional object can be regarded as the above-mentioned difference A collection of voxels at spatial positions. When we simulate and record the spatial light field of each voxel in turn, we can finally achieve the purpose of recording 3D object information with two-dimensional materials. From Figure 3, we can see that each microlens is like a tiny camera, which images the three-dimensional object from different spatial positions. Due to the limitation of the radiation space range of the simulated light field, a single microlens can only The local imaging of , we call the image formed behind each microlens a sub-image. It can be seen that it is these two-dimensional sub-graphs that complete the information decomposition of three-dimensional objects.

Please refer to FIG. 4 , which is a schematic diagram of a microlens film reproducing a floating three-dimensional image of an object by reflecting ambient light. The light rays 201a and 201b in the figure are randomly irradiated ambient light, 202 is a pixel recorded by the microlens recording material in FIG. 3 , and 203a and 203b are refracted light from the lens to the base material. Based on the principle of light reversibility, the image of the sub-image will be projected and imaged by the microlens array at the original space position, and the set of images formed by the sub-image is the reproduction of the three-dimensional object image. What needs to be emphasized here is that the thin film material of the present invention can reproduce objects not only by using reflected light, but also by illuminating transmitted light. When observing the object image, since the human eye can only partially receive the image formed by these sub-image arrays, only part of the information of the object can be seen at a fixed viewing angle. When the observer changes the relative position of the imaging material, such as Flip the material up and down, left and right, or move the observer's spatial position, you can see the information of different positions of the object, that is, realize the dynamic three-dimensional object effect that different parts of the object can be seen under different viewing angles.

Based on the above analysis, it can be seen that the radiation characteristics of the simulated converging laser light field play an important role in the final imaging effect. Including, the spatial position coordinates (x, y, z) of the focused light spot of the converging laser (determining the effect of floating or sinking), the numerical aperture NA of the converging laser (determining the size of the field of view), especially in the scheme of the present invention , since the cylindrical lens only deflects and converges light in one-dimensional direction, the actually obtained voxel radiation light field is a fan-shaped area, rather than a cone obtained by using a circular lens. Therefore, when the orientation angle θ of the fan-shaped radiation light field is changed as an independent variable, it has a particularly important influence on the dynamic imaging effect. Its function will be analyzed in detail later in the examples.

The numerical aperture NA of the laser printing optical system determines the size of the maximum observable field of view, that is, the image of the reproduced object can be seen within the range of angles. The larger the NA, the larger the field of view and the stronger the dynamic sense . In general, the numerical aperture of the optical system is determined, that is, the numerical aperture is constant, which means that the field angle range of each voxel simulated by the system is equal, so although the field angle has a certain value range, but for the volumetric Pixels are still considered constants as far as describing objects are concerned.

The voxel light field radiation simulated in the printing device of the present invention is controlled by four independent parameters, please refer to Figure 5, which is a schematic diagram of the calibration direction of the spatial coordinate system and the rotatable cylindrical lens of the independent parameters in the light field imaging printing device, and the agreed space The coordinate system is a right-handed coordinate system. The positive direction of x-y-z is shown in the figure. The cylindrical lens orientation angle of 0° is calibrated as the positive direction of the x-axis, and the counterclockwise rotation is positive, and the value range is 0-360°.

Referring to FIG. 6, FIG. 6 is a schematic diagram of a light field imaging printing device. The structural system shown in FIG. 6 includes a microlens recording material 1, a light source 2, a scanning galvanometer system 3, a cylindrical lens 4, a diffusion sheet 5, a converging lens group 6 and a scanning The light cluster 7 , the scanning galvanometer system 3 includes a galvanometer 31 , a galvanometer 32 and an f-theta (flat-field focusing) lens 33 . As shown in FIG. 6 , the cylindrical lens 4 is placed near the focal plane of the f-theta lens 33 , the diffuser 5 is placed on the focal plane of the cylindrical lens 4 , and an adjustable distance is kept between the diffuser 5 and the upper end of the lens group 6 . Since the f-theta lens 33 has a longer focal length, it can be seen that the light scanned on the surface of the cylindrical lens 4 is a parallel beam. When the light field imaging and printing device works, firstly, the light source 2 emits laser light, and the scanning galvanometer system 3 is controlled by computer software, and the outgoing light 7 passing through the f-theta mirror 33 performs high-frequency reciprocating linear scanning on the surface of the cylindrical lens 4, and is controlled by the computer. Precisely control the rotation of the cylindrical lens 4, and at the same time ensure that the light scanning direction remains perpendicular to the optical axis of the cylindrical lens 4, then after the one-dimensional deflection of the cylindrical lens 4, the scanning light cluster 7 converges on the surface of the diffusion sheet 5, because the diffusion sheet 5 For the random scattering of the light cluster 7, the laser light intensity with Gaussian distribution characteristics is homogenized, and the diffusion angle of the light cluster 7 is also increased. After the collection and convergence of the light beam by the lens group 6, an instantaneous dynamic output can be output. Focusing the light spot V means obtaining a voxel radiation light field, and then recording the instantaneous voxel light field information by the microlens recording material 1 . When printing a three-dimensional object, the x-y-z platform where the microlens recording material 1 is located is controlled by a computer to obtain voxels at different spatial positions, thereby finally completing the printing record of the light field of the 3D object. The four-dimensional variables in the present invention include three-dimensional space coordinate variables and cylindrical lens rotation orientation angle variables, and the variables can be freely combined to reduce the four-dimensional variables to three-dimensional or two-dimensional. Wherein, the numerical aperture of the cylindrical lens 4 is between 0.3 and 0.95, which focuses the incident light in one dimension and directly transmits the light in the other dimension, and the beam that continues to propagate from the converging point spreads in a fan-shaped area. The field of view angle that can dynamically observe the object image can be calculated by the numerical aperture of the converging lens group. The calculation formula is φ=2arcsin(NA), and NA is the numerical aperture of the converging lens group 6, that is, the maximum viewing angle is equal to 2 times of the arcsine of the numerical aperture.

Compared with the existing invention patents described in the background art, the light field imaging printing device of the present invention has two main differences. On the one hand, the present invention adopts the method of linear scanning on the cylindrical lens 4 to obtain an instantaneous and dynamically changing voxel converging light field. Please refer to Fig. 7. Fig. 7 is an enlarged view of a part of the single beam of the beam cluster 7 scanned by the vibrating mirror system 3 on the cylindrical lens 4. Since the laser beam emitted by the laser light source can be regarded as a parallel light with a certain geometric diameter, such as an optical fiber The laser emits a laser beam with a wavelength of 1064nm and a diameter of about 8mm. After the parallel light beam 71 passes through the cylindrical lens 4, the angle of the outgoing light changes. After the diffuser 5 spreads the beam uniformly and the lens group 6 converges, a converging printing beam 711 is obtained. As the light beam 71 continuously scans on the cylindrical lens 3 to the beam At position 73, the printing beam also changes continuously from printing beam 711 to printing beam 731, that is, the angle of the incident beam changes continuously, which not only improves the range of viewing angle, but also realizes continuous adjustment of viewing angle. Please refer to FIG. 8. FIG. 8 is an enlarged view of the printing beams 711, 721, and 731 in FIG. A point can be regarded as a sub-pixel. Due to the high-frequency scanning of the scanning galvanometer system 3, when the light beam 71 scans from the surface of the cylindrical lens 4 to the position 73, many sub-pixels corresponding to different viewing angles can be obtained. A unit macro pixel, that is, a voxel V shown in FIG. 8 is formed in a short period of time. The light field radiated by such an individual pixel has the following characteristics: large viewing angle, uniform distribution of light energy, high imaging definition, and strong dynamic sense of 3D light field imaging.

On the other hand, the cylindrical lens 4 can rotate precisely around the Z axis (ie, the optical axis) passing through its own geometric center, as shown in FIG. 7 . It has been pointed out above that the rotation angle of the cylindrical lens determines the orientation angle of the radiated light field in the fan-shaped area, so in the four-parameter light field expression L(x, y, z, θ), the variable θ is the cylindrical lens The rotation angle, or the orientation angle of the cylindrical lens, has a value range of 0-360° and can be precisely adjusted. When a certain value θ is used to print 3D light field data, the observer can only observe the image of the object in the fan-shaped plane of the corresponding orientation. When deviating from this orientation angle, such as rotating the recording material 1 by an angle, the object image will be will disappear.

Here, the two different concepts of orientation angle and field angle mentioned in this article are emphasized. The field of view is defined as different observation points can be selected in a certain plane, so the viewing angle changes. For example, the observer only moves the position in the x-y plane to change the viewing angle, but if the x-y plane flips, it is obviously the same. Change the observer's viewing angle, such as flipping the x-y plane to the y-z plane. Therefore, the plane's flip angle is defined as the orientation angle of the plane. In the above description, it is precisely because the rotation cylinder lens can achieve different orientation angles of the observation plane. Therefore, the observer can not only change the viewing angle in the same plane, but also change the viewing angle in different planes. The essence is that the viewing angle parameter needs to be controlled by two-dimensional direction variables. However, for the laser printing device in this paper, the value range of the viewing angle in the same plane is are all the same, it can be regarded as a constant, and only the orientation angle is used as a variable to represent the viewing angle parameter.

In the four-variable light field L(x, y, z, θ) printing system in the present invention, since the spatial coordinate variable x-y-z and the cylindrical lens orientation angle variable θ are independent of each other, when one variable is fixed, only the other three variables are changed to print 3D When viewing an object, many unique 3D dynamic perspective effects can be reproduced, which will be described in detail through several specific embodiments below.

Implementation mode 1:

In the light field imaging printing device shown in Figure 6, when printing, the cylindrical lens 4 is fixed to a certain orientation angle, and the computer controls the scanning galvanometer system 3 to keep the laser scanning on the circular arc surface of the cylindrical lens, and then passes through the converging lens group 6 The obtained voxel light field is a fan-shaped surface with a fixed orientation angle, and is recorded by the microlens recording material 1. According to the input 3D model data, the x-y-z platform where the microlens recording material 1 is located is controlled, and the light field recording of the 3D object is realized by horizontal layer-by-layer printing. Since the light field of all voxels of this 3D object is a fan-shaped area with the same orientation angle, the object can only be observed in the collection plane with this orientation angle during reproduction. When the observer changes continuously in this orientation plane Dynamic effects are visible when looking at the viewing angle. As shown in Figure 9, the observer continuously changes from viewing angle 3 to viewing angle 4 within the paper to see a dynamic cube figure, and when the viewing angle leaves the paper, the object will disappear. Therefore, the 3D reproduction with such viewing angle characteristics can only be watched by one person, and cannot be watched by multiple people at the same time, which can well protect the privacy of the observers.

Implementation mode 2:

In Embodiment 1, the voxel light field can be expressed as L1(x, y, z). After completing the 3D light field imaging and printing, rotate the cylindrical lens 4 and repeat the above printing process to input another 3D object light field data L2(x, y, z), when the cylindrical lens 4 is rotated to different orientation angles, the light field data Ln(x, y, z) of different 3D objects are sequentially input. When reproducing, the principle is as described in Embodiment 1. The observer can only observe different 3D printed objects sequentially within the selected orientation angle fan-shaped collection plane. As shown in Figure 10, when at the orientation angle position, you can observe Cubic model, spherical model again visible when rotating the recording material to the orientation angle. The 3D reproduction with such viewing angle characteristics can allow multiple people to observe different object information from different directions, realizing the multiple reuse of the same space for recording materials, and increasing the storage density of material information. If an orientation angle is taken at intervals such as 15°, a 3D model is printed at each orientation angle, and these 3D models belong to a frame of a dynamically changing 3D video, such as a running animal or a rotating character Model, the orientation angle of 0-360° can input 12 frames of 3D images. When the observer quickly rotates the microlens recording material 1 to change the orientation angle, due to the persistence of the human eye’s perspective, a dynamic 3D animation effect can be seen. It should be pointed out that since the pupil of the human eye is circular, only when the observer observes vertically directly above the material, the graphic information of different orientation angles will be received at the same time. observation at an oblique angle. Here, it is emphasized that each frame of image is three-dimensional rather than two-dimensional, indicating that the observer can observe different sides of the same frame of 3D objects at different inclination angles (ie, field of view), which increases the realism of observing dynamic objects .

Implementation mode 3:

As a special example of Embodiment 2, the rotation of the cylindrical lens 4 makes the orientation angle change continuously instead of having a discrete value. Here the rotation frequency of the cylindrical lens 4 should be much lower than the scanning frequency of the scanning galvanometer system 3, to ensure that the scanning galvanometer system 3 can still move the cylindrical lens 4 when the rotation angle is lower than 1 milliarc (ie 1mrad). At least one complete scanning period is completed on the arc surface of the lens 4 . Assuming that the scanning frequency of the scanning galvanometer system 3 is T1, and the rotation frequency of the cylindrical lens 4 is T2, according to the above conditions, it should be ensured that the time for the cylindrical lens 4 to rotate 1mrad is not less than 1/T1, so that the relationship T2≤ T1/(2000π), such as T1=200000Hz, after calculation, the rotation frequency of the cylindrical lens 4 should not be greater than 31Hz. If the above conditions are met, the voxel radiation output by the printing system can be regarded as a four-variable light field L(x, y, z, θ), and each voxel light field can be regarded as a 360° rotation cone of a certain orientation angle sector body. The high-frequency scanning of the scanning galvanometer system 3 and the rotation of the cylindrical lens 4 work together. It can be understood that the volume pixel is no longer a single pixel, but a combination of many sub-pixels corresponding to different fields of view (in the scanning direction). Micro-large field of view macro-pixels are jointly synthesized, and the positions of sub-pixels with different field of view angles are different, and they are close together. The micro-lens recording material 1 has a high imaging definition of the small field of view light field, so that the dynamic sense of 3D light field imaging is strong. . As shown in Figure 11, a cube model is printed using the implementation method of this example. When reproducing, the observer can not only see the 3D model from a certain position, but also observe around the model at 360°. When observing at a fixed position, the human eye partially receives the light field information of the model. At this time, the micro-lens recording material 1 can be flipped up and down, left and right, and a dynamic 3D effect can be seen; when viewed as a peripheral view, the object space is kept The position is fixed, and the observer rotates around the object, and can observe the information of the front, back, left, and right directions of the 3D object, and the sense of space reality is greatly enhanced.

Implementation mode 4:

Fix the z-axis height of the microlens recording material 1 in the light field imaging printing device shown in Figure 6, and fix the orientation angle of the cylindrical lens 4 as θ, and control the platform to move only in the x-y direction, then the four-dimensional voxel light field expression is reduced to Two-dimensional L1(x, y), according to which a floating or sinking two-dimensional light field pattern with multiple viewing angles or continuously changing viewing angles can be printed. Different from the existing patents described in the background technology, the printing of multi-view two-dimensional graphics in the solution of the present invention does not need to print the multi-view graphics one by one, but directly outputs a macro pixel by scanning the vibrating mirror , the macro-pixel includes many sub-pixels with different viewing angles, and each sub-pixel corresponds to a pixel to be input with a multi-viewing image.

For better understanding, with reference to Fig. 7, 8, 12, the beams 71, 72, 73 in Fig. 7 are three beams in a certain scanning period (and only do the three-position discrete scanning in each scanning period), which The corresponding three printing beams are 711, 721, and 731 in Fig. 8 respectively. It has been pointed out above that 711, 721, and 731 respectively represent three different incident angles of view. When scanning, the pulse switch of the light source 2 can be controlled to use this The three converging light beams respectively represent three pixels at the same position in the three perspective images, and these three sub-pixels constitute the macro pixel V. Laser pulse on and off should be controlled according to the pixel information of the graphics to be input. Referring to FIG. 12 , the figure shows the pixel arrangement of the three binary view images, and the arrangement of the two rectangular strips above represents the macro-pixels composed of three pixels arranged in order in the same position of the three view images. Using the pulsed laser on to represent the pixel value 1, and the pulsed laser off to represent the pixel value 0, then the macro pixel V in Figure 8 can be composed of three sub-pixels v1, v2, and v3 respectively. Using the pulsed laser on and off, the value of V can be expressed as 1-1-1, when moving to the next position, the scanning galvanometer system 3 repeatedly scans the three-view light on the cylindrical lens 4, and outputs the macro pixel value V composed of three sub-pixels at this position according to the pixel information of the graphic ’, as shown in FIG. 12, it is 1-0-1, and so on, until the pixel information of all viewing angle graphics is output. It can be seen that the 3 pixel information input at each position is an orderly arrangement of the same position in each view image, for example, the order of the position of each view image pixel matrix (1, 1), due to the scanning The frequency is high, and this method is instantaneous in batch input of multi-view images, and there is no alignment problem of multiple input view images, so the efficiency is high. Especially when making graphics with continuous viewing angle changes, this efficiency is difficult to achieve in existing solutions.

The graphics to be input in this embodiment are not limited to multi-view images of the same object, but may also be two-dimensional graphics of different objects. When the input is multiple views of the same object, since the two eyes of the observer can receive the views with parallax respectively, after the brain synthesizes the two parallax projections, you can feel the object floating or sinking relative to the surface of the material Stereoscopic effect, the microlens recording material 1 is shaken to change the viewing angle, and an obvious dynamic 3D effect can be seen. If the input is a different object image, shake the microlens recording material 1 to see the dynamic image changing effect, such as observing a running rabbit, which has been described above and will not be described again. When the input of the above-mentioned multi-view image light field L1(x, y) is completed, the orientation angle of the cylindrical lens 4 can be changed to input the next set of multi-view image light field L2(x, y), so as to realize multiple materials in the same space. use.

Implementation mode 5:

In Embodiment 4 above, after printing the light field data L1(x, y), adjust the height of the x-y-z platform, and print another light field data L2(x, y) in the same way, then a floating image and a sinking image can be reproduced. When the image is floating up and down, a strong sense of 3D depth of field will be obtained, and the viewing angle can be continuously changed in the fan-shaped plane with an orientation angle of , showing obvious dynamic effects. Referring to the floating streamer 9 shown in Fig. 13, the print data of the two-dimensional light field L1 corresponds to the floating sine streamer 91, and the print data of the light field data L2 corresponds to the sinking streamer 92, and the amplitude and period of the floating sine streamer 91 and the sinking sinusoidal streamer 92 are the same , the phase difference between the two is π/4, the upper view is the relative position relationship between the floating sinusoidal streamer 91 and the sinking sinusoidal streamer 92 observed by the observer at the viewing angle a, and the middle view is the floating sinusoidal streamer 92 observed by the observer at the viewing angle b Another relative positional relationship between the streamer 91 and the sinking sinusoidal streamer 92 , the lower layer view is the geometric spatial position of the floating sinusoidal streamer 91 and the sinking sinusoidal streamer 92 observed by the observer at the viewing angle c. It can be seen that when the viewing angles are different, the two sinusoidal streamers are dislocated, and the observer's viewing angle continuously changes from a to c, that is, it can be seen that the relative position of the two streamers has an obvious dynamic change.

Implementation mode 6:

Please refer to FIG. 14. In FIG. 14, the cylindrical lens 4 used in the present invention is replaced by a circularly symmetrical spherical lens 8 or an aspheric lens with better focusing ability and a numerical aperture that matches the cylindrical lens, or a combination with aberration correction. Instead of lenses, the numerical aperture NA of the spherical lens 8 is not smaller than the numerical aperture NA of the cylindrical lens 4 . When the scanning galvanometer system 3 linearly scans along the horizontal axis of symmetry of the spherical lens 8, the output end of the converging lens group 6 can also obtain the volume pixel light field in the fan-shaped area, and control the ray trajectory to scan along the horizontal axis of symmetry in different orientations. That is, the non-rotating spherical lens 8 can also be used to obtain fan-shaped surfaces with different orientations without the need for the rotating cylindrical lens 4 to realize the printing mode in the present invention. Please refer to Fig. 15, Fig. 15 is the front view projection diagram of scanning galvanometer system 3 on the surface scanning track of spherical lens 8, line segments 81, 82 are two horizontal symmetry axes of spherical lens 8, and line segments 81, 82 are also orientation angles respectively are the scanning rays of θ3 and θ4. In this embodiment, the orientation angle of the scanning light is the θ variable in the four-variable light field L(x, y, z, θ). The difference is that the converging light spot of the cylindrical lens 4 is narrow and long. Since it only focuses in one dimension, the influence of Gaussian light spot unevenness is small, which is beneficial to the light intensity uniformity of sub-pixel tiling printing in the scanning direction, and can provide excellent The imaging quality of the microlens array and the effect of spatial multiplexing. The advantage of using the spherical lens 8 is that the orientation angle variable θ can be obtained without mechanical rotation. However, using the focusing of the symmetrical spherical lens 8, the inhomogeneity of the Gaussian spot reduces the available energy efficiency. It still has a focusing effect, so for the sub-pixels described in Embodiment 4, its observable viewing angle distribution has spatial circular symmetry. When viewed at different orientation angles, the reproduced image is likely to crosstalk with the image at the previous orientation angle, thus Reduce the viewing experience of dynamic 3D. Therefore, the present invention preferably adopts the scheme of cylindrical lens rotation.

To sum up, the light field imaging printing device in the present invention mainly utilizes the scanning galvanometer system to scan on the lens surface and combine with the change of the spatial three-dimensional coordinates to realize the four-dimensional light field data printing. Laser pulse switching, cylindrical lens rotation, galvanometer system scanning, and x-y-z platform movement all need to be controlled in an orderly manner according to the graphic information to be input. Thus, a film with a more realistic three-dimensional dynamic image can be realized, and various floating images with different characteristics can be realized by controlling different variable values. It is ensured that imaging effects such as multi-view image change can be achieved, and a more realistic three-dimensional observation experience of objects can be obtained. In addition, different images can also be printed from different orientation angles to prepare a three-dimensional image film with spatial multiplexing.

It will be apparent to those skilled in the art that the invention is not limited to the details of the above-described exemplary embodiments, but that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Accordingly, the embodiments should be regarded in all points of view as exemplary and not restrictive, the scope of the invention being defined by the appended claims rather than the foregoing description, and it is therefore intended that the scope of the invention be defined by the appended claims rather than by the foregoing description. All changes within the meaning and range of equivalents of the elements are embraced in the present invention. Any reference sign in a claim should not be construed as limiting the claim concerned.

In addition, it should be understood that although this specification is described according to implementation modes, not each implementation mode only contains an independent technical solution, and this description in the specification is only for clarity, and those skilled in the art should take the specification as a whole , the technical solutions in the various embodiments can also be properly combined to form other implementations that can be understood by those skilled in the art.

Claims (12)

1. A kind of 1. optical field imaging printing equipment, it is characterised in that：Including light source, scanning galvanometer system, lens, diffusion sheet, convergence Lens group and lenticule recording materials, the scanning galvanometer system include galvanometer and f-theta lens, and the lens are placed in flat The focal plane of field condenser lens, the diffusion sheet are placed on the focal plane of lens, and diffusion sheet is protected with assembling the upper end of lens group One section of adjustable distance is held, the light source launches laser, and it is saturating with assembling that light is scanned through galvanometer system, lens, diffusion sheet successively Microscope group, the focal beam spot of transient behavior is exported, obtain volumetric pixel radiation light field, then recorded instantaneously by the lenticule recording materials Volumetric pixel radiates field information, and the volumetric pixel radiation light field is controlled by four Independent Parameters, including three dimensional space coordinate variable And lens orientation angle variable, between variable can free valued combinations, by four-dimensional variable drop into three-dimensional or two dimension.
2. A kind of 2. optical field imaging printing equipment as claimed in claim 1, it is characterised in that：The lenticule recording materials include Microlens array and the light-sensitive layer below microlens array, the microlens array are by clear aperature and relief depth For the array of micron-sized lens composition, the light-sensitive layer is that irreversible light becomes material.
3. A kind of 3. optical field imaging printing equipment as claimed in claim 1, it is characterised in that：The light source launches laser, through sweeping Galvanometer system emergent ray is retouched, makees linear scan in lens surface, forms scanning ray cluster, after lens, scanning ray cluster meeting Gather on the diffusion sheet surface, and scattered, the convergent lens group is collected convergence to light beam.
4. A kind of 4. optical field imaging printing equipment as claimed in claim 1, it is characterised in that：When printing three-dimensional body, mobile institute The x-y-z platforms where lenticule recording materials are stated to obtain the volumetric pixel of different spatial.
5. A kind of 5. optical field imaging printing equipment as claimed in claim 1, it is characterised in that：The fixed lenticule recording materials Z-axis height and lens the angle of orientation, the platform where lenticule recording materials only makees the movement in x-y directions, then four-dimensional body image Plain light field expression is reduced to two dimension, and thus printing is with various visual angles or the suspension at consecutive variations visual angle or the two-dimension light field figure of sinking Shape, using galvanometer scanning system, a grand pixel directly being exported, the grand pixel includes the sub-pixel of many different visual angles, Each sub-pixel correspond to the pixel of various visual angles figure to be entered.
6. A kind of 6. optical field imaging printing equipment as claimed in claim 1, it is characterised in that：The lens are from post lens, circle Symmetrical spherical lens, focusing power more preferably and numerical aperture match with post lens non-spherical lens, there is aberration correction Compound lens in one kind.
7. A kind of 7. optical field imaging printing equipment as claimed in claim 6, it is characterised in that：The lens select post lens, post The numerical aperture of lens focuses between 0.3~0.95, to incident ray in one-dimensional square, another direct transmitted ray of dimension, by The light beam that convergent point continues to propagate spreads into sector domain.
8. A kind of 8. optical field imaging printing equipment as claimed in claim 7, it is characterised in that：The post lens are around its own geometry The Z axis rotation at center, the anglec of rotation of post lens are determined the angle of orientation of sector domain radiation light field, determined when using a certain angle of orientation During value printing 3 d light fields data, observer can only observe image in the sector of this angle of orientation, when this angle of orientation of deviation When, then picture drop-out or observe deviate after oriented surface in image.
9. A kind of 9. optical field imaging printing equipment as claimed in claim 6, it is characterised in that：The lens select spherical lens, Horizontal symmetry axis dimension linear scanning of the scanning galvanometer system along spherical lens, convergent lens group output end obtains fan-shaped Face domain volumetric pixel radiation light field.
10. A kind of 10. film with three-dimensional floating image, as the optical field imaging printing equipment any one of claim 1-9 Prepare, it is characterised in that：The field information of one or more objects is have recorded, be reproduce and suspended or sink relative to film surface Floating image, the floating image synthesizes by the subgraph of multiple different visual angles, can be observed from different spatial views.
11. A kind of 11. film with three-dimensional floating image as claimed in claim 10, it is characterised in that：In an oriented surface It was observed that image, be same object various visual angles figure or several different images, when deviateing the oriented surface, then image disappears Lose or observe the image in the oriented surface after deviateing.
12. A kind of 12. film with three-dimensional floating image as claimed in claim 10, it is characterised in that：The floating image is Two dimensional image or 3-D view, when being 3-D view, floating image is the three-dimensional for being apparent in film top, thin film planar or lower section Depth image, or from a depth to the 3-D view of another depth consecutive variations.