Imaging device for customizing illumination free-form surface based on light and free-form surface design method

Abstract

The invention discloses an imaging device for customizing an illumination free-form surface based on light and a free-form surface design method, and the method comprises the steps: determining basic optical parameters and a target pattern, and carrying out the sampling of an incident plane and a focal plane; performing coarse matching on the incident light and the emergent light of the lens to obtain a coarse matching light pair; calculating a surface normal vector of the surface of the lens by using a Snell law according to the rough matching light pair; based on the surface normal vector, utilizing a Poisson equation to construct an initial surface; performing fine matching on the initial surface to obtain a fine matching light pair; and based on the fine matching light pairs, performing global and local optimization by adopting a hierarchical optimization method to obtain design surface data of the free-form surface. The imaging device comprises a light source and the free-form surface. By introducing systematic design thoughts and optimization strategies, the method can be popularized and used in different fields and applications, and modularization and standardization of lighting system design are achieved.

Description

Technical Field

[0001] The present invention belongs to the field of customized lighting technology, and in particular relates to an imaging device for a free-form surface based on customized lighting of light and a free-form surface design method. Background Art

[0002] Customized lighting is a technology that uses processed light from a light source to achieve the desired lighting effect, such as road lighting, car lighting, etc. In practical applications, different light distributions may be required to achieve different lighting effects. However, directly applying light sources usually cannot meet the requirements. Efficiently adjusting the spatial energy distribution of light sources is a research area of ​​customized lighting and is a classic and challenging problem in the field of non-imaging optics.

[0003] Since the radius of curvature is the only design freedom that traditional spherical surfaces can provide, custom lighting often uses aspherical surfaces to redirect the light beam. Aspherical optics can handle rotationally or linearly symmetrical lighting designs very effectively, but due to the rotational or linear limitations of the surface geometry, they usually cannot solve asymmetric lighting problems well and cannot meet the growing needs of advanced lighting systems. Freeform surfaces are three-dimensional controllable optical surfaces. Their free form provides powerful degrees of freedom, which can be used to avoid restrictions on surface geometry and create compact and efficient designs with better performance. More importantly, the use of deformable surfaces can produce new designs that cannot be achieved using spherical or aspherical surfaces.

[0004] Although free-form surfaces can theoretically achieve arbitrary customized lighting, their large degrees of freedom make design difficult. Current research is based on complex mathematical derivations, but has not yet found a definite and precise solution, which limits the degrees of freedom in actual design and makes it easy for no solution to occur. In addition, the methods are generally based on illumination design and cannot achieve accurate light-level lighting. At the same time, current designs are not systematic and there is no clear design link. Summary of the invention

[0005] The present invention aims to solve the deficiencies of the prior art and provides the following solutions:

[0006] An imaging device based on customized illumination of a free-form surface by light comprises a light source and a free-form surface lens. The light source and the free-form surface lens are arranged separately. The light emitted by the light source passes through the free-form surface lens and is directly converged into a required customized pattern illumination.

[0007] The present invention also provides another imaging device based on customized light illumination of a free-form surface, comprising a light source and a free-form surface lens, wherein the light source is directly placed on the free-form surface lens, the incident surface of the free-form surface lens is a collimating surface, and the exit surface is a free surface.

[0008] The present invention also provides a free-form surface design method for customized light illumination, the design method is used to design any of the above-mentioned free-form surface lenses, comprising the following steps:

[0009] Determine basic optical parameters and target patterns, and sample the incident surface and focal plane, wherein the optical parameters include: transmission refractive index, output space refractive index, focal plane position, lens position, and sampling quantity;

[0010] Roughly matching the incident light and the outgoing light of the lens to obtain a rough matching light pair;

[0011] Calculating a surface normal vector of the lens surface using Snell's law according to the roughly matched light pair;

[0012] Based on the surface normal vector, construct an initial surface using Poisson's equation;

[0013] Performing precise matching on the initial surface to obtain a precise matching light pair;

[0014] Based on the precisely matched light pair, a hierarchical optimization method is used to perform global and local optimization to obtain the design surface data of the free-form surface lens.

[0015] Preferably, the sampling method includes: using concentric circle sampling:

[0016]

[0017]

[0018]

[0019] Where l represents the number of radial rings sampled, N0 represents the ideal number of samples, S represents the area of ​​the sampled pattern, rl represents the radius of the lth ring from the center of the circle, r1 represents the radius of the first ring from the center of the circle, p represents the free surface position of the sampled pattern in the rectangular coordinate system, p0 represents the center of the pattern, r n represents the radius of the nth ring, c n Indicates the number of samples of the nth ring, N + Represents the set of natural numbers except 0.

[0020] Preferably, the method for obtaining the coarse matching light pair comprises:

[0021] Obtaining the point set X of the incident light and the point set T(X) of the outgoing light;

[0022] The point set X and the point set T(X) are roughly matched, and a matching mapping that minimizes the cost function is found in the point set T(X), to obtain the roughly matched light pairs V and V':

[0023] min T ∑ X c0(X,T(X))

[0024] Among them, c0(μ,ν) represents the cost function of coarse matching.

[0025] Preferably, the method for calculating the surface normal vector comprises:

[0026] V′=V+ηN

[0027]

[0028] Where V represents the incident light of the coarse matching light pair, V' represents the outgoing light of the coarse matching light pair, N represents the surface normal vector, represents the transmission refractive index, represents the refractive index of the exiting space, η represents the coefficient of the unit normal vector, and θ represents the incident angle.

[0029] Preferably, the method for constructing the initial surface comprises:

[0030] The surface normal vector is gradient-solved, and the surface point cloud is solved by Poisson's equation:

[0031]

[0032]

[0033] H=grad(φ)·N

[0034] Where φ represents the surface point cloud, Indicates taking divergence, grad means finding gradient, n means function normal vector, H means the current solution value of the equation, and Q means taking the divergence value twice;

[0035] Performing a vector displacement cycle on the surface point cloud to make the height of the surface center point equal to the position p of the free-form surface, while ensuring the relative height of each surface point, and solving the Poisson equation again until the error is within the error limit, thereby obtaining the initial surface;

[0036] e(x, y)=||φ(x, y)-φ0(x, y)||2>e0

[0037] Among them, e represents the error function, φ(x, y) represents the surface point cloud of the current cycle, φ0(x, y) represents the surface function of the previous cycle, and e0 represents the error limit.

[0038] Preferably, the method for obtaining the precisely matched light pair comprises:

[0039] Obtaining a point set X' of incident light rays and a point set T(X') of outgoing light rays of the initial surface;

[0040] The point set X' and the point set T(X') are precisely matched, and a matching mapping that minimizes the cost function is found in the point set T(X'), to obtain the precisely matched light pair:

[0041] min T ∑ X′ c(X′, T(X′))

[0042] c(u,v)=∫(F(u,v)+c0(u,v))dγ(u,v)

[0043] Among them, c(μ, v) represents the cost function of the precise matching, F(u, v) represents the precise matching amount, and γ(u, v) represents the integral domain mapping function.

[0044] Compared with the prior art, the present invention has the following beneficial effects:

[0045] 1. The present invention optimizes the design of various parameters in the lighting system by introducing numerical calculations, and at the same time, changes the structure of the cost function so that it can be closer to the most natural light matching state; this method allows designers to more flexibly adjust and optimize the distribution and characteristics of light without relying on traditional continuous mathematical conditions; the method provided by the present invention can not only achieve more accurate lighting control in complex geometric structures and multi-light source systems, but also explore the optimal solution under specific constraints, effectively solving the problem of limited design freedom in traditional methods, thereby greatly improving the design flexibility and applicability of customized lighting systems, and providing solid technical support and theoretical basis for realizing more efficient and intelligent lighting solutions;

[0046] 2. The present invention can realize the customization of a single light ray by introducing the refractive index matrix, rewriting the precise matching cost function and the independence of the numerical method from the physical model. The specific properties of each light ray can be independently adjusted. For different light source conditions, the light propagation path can be precisely controlled, which can not only effectively reduce unnecessary light loss, but also avoid the irregular distribution of light in space, thereby providing a more uniform and satisfactory lighting effect in different application scenarios. Therefore, the precise control of a single light ray not only breaks through the limitations of traditional illumination control, but also provides a new technical path for achieving higher quality and more efficient lighting effects.

[0047] 3. The present invention introduces a systematic design idea and optimization strategy, and proposes a customized lighting design chain of coarse matching-initial structure-fine matching-multi-dimensional adaptive optimization. This universal design chain can not only improve the efficiency of customized lighting design, but also be promoted and used in different fields and applications to achieve modularization and standardization of lighting system design. The present invention contributes to the systematicness and standardization of the customized lighting field. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] In order to more clearly illustrate the technical solution of the present invention, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0049] Figure 1 This is a schematic structural diagram of an imaging device according to a first embodiment of the present invention;

[0050] Figure 2 This is a schematic structural diagram of an imaging device according to a second embodiment of the present invention;

[0051] Figure 3 This is a schematic diagram of the method flow of Embodiment 3 of the present invention;

[0052] Figure 4 This is a schematic diagram of a target pattern of Embodiment 3 of the present invention;

[0053] Figure 5 This is a schematic diagram of sampling in Embodiment 3 of the present invention;

[0054] Figure 6 This is a schematic diagram of a rough matching situation of the third embodiment of the present invention;

[0055] Figure 7 is a schematic diagram of an initial surface of Embodiment 3 of the present invention;

[0056] Figure 8 Schematic diagram of the design result of the free-form surface of the third embodiment of the present invention. DETAILED DESCRIPTION

[0057] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0058] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0059] Embodiment 1

[0060] In this embodiment, an imaging device is provided, comprising: a light source and a free-form surface lens, wherein the light source and the free-form surface lens are separately arranged. Figure 1 As shown, the light emitted by the light source passes through the free-form surface lens and is directly converged into the required customized pattern lighting. The imaging device abandons the fragile, easily polluted, and low light energy efficiency film pattern lighting method, has the advantages of compact structure, high light energy utilization, and is durable and not easy to damage, greatly improving the product performance and competitiveness of customized pattern lighting.

[0061] Embodiment 2

[0062] In this embodiment, an imaging device is provided, comprising: a light source and a free-form surface lens, wherein the light source is directly placed on the free-form surface lens. Figure 2 As shown, the incident surface of the free-form surface lens is a collimating surface, and the exit surface is a free surface. The imaging device directly uses LED to expand the light source, without the need for a separate collimating lens, and does not use film pattern lighting. It has the advantages of more compact structure, small space occupancy, high light energy utilization, and is durable and not easy to damage. It greatly improves the product performance and usage scenarios of customized pattern lighting, reduces costs, and increases product competitiveness.

[0063] Embodiment 3

[0064] In this embodiment, if Figure 3 As shown, a free-form surface design method for light customized lighting includes the following steps:

[0065] S1. Determine basic optical parameters and target pattern, and sample the incident surface and focal plane. The optical parameters include: transmission refractive index, output space refractive index, focal plane position, lens position and sampling quantity.

[0066] In this embodiment, the basic optical parameters include: lens refractive index Outgoing spatial refractive index The focal plane position f = 130, the free-form surface position p = 30, the free-form surface aperture D = 50, and the number of samples is 30000. The customized target pattern is as follows Figure 4 shown.

[0067] The sampling method includes: In this embodiment, in order to ensure the circular shape of the cut-off caliber and ensure the accuracy of the design, uniform concentric circle sampling is adopted:

[0068]

[0069]

[0070]

[0071] Wherein, l represents the number of radial rings sampled, N0 represents the ideal number of samples, which is 30000 in this embodiment, S represents the area of ​​the sampled pattern, which is S=625π in this embodiment, r l represents the radius of the lth ring from the center of the circle. In this embodiment, r l = 25, r1 represents the radius of the first ring from the center of the circle, p represents the free surface position of the sampling pattern in the rectangular coordinate system, p0 represents the center of the pattern, r n represents the radius of the nth ring, c n Indicates the number of samples of the nth ring, N + represents the set of natural numbers except 0; solving the formula yields:

[0072]

[0073] Sampling conditions such as Figure 5 shown.

[0074] S2. Roughly match the incident light and the outgoing light of the lens to obtain a roughly matched light pair.

[0075] The method for obtaining a rough matching light pair includes: obtaining a point set X of incident light and a point set T(X) of outgoing light; performing rough matching on the point set X and the point set T(X), such as Figure 6 As shown, find the matching mapping that minimizes the cost function in the point set T(X) and obtain the rough matching light pairs V and V':

[0076] min T ∑ X c0(X,T(X))

[0077] Among them, c0(μ,ν) represents the cost function of coarse matching.

[0078] S3. Calculate the surface normal vector of the lens surface using Snell's law based on the roughly matched light pair.

[0079] Methods for calculating surface normal vectors include:

[0080] V′=V+ηN

[0081]

[0082] Where V represents the incident light of the coarse matching light pair, V' represents the outgoing light of the coarse matching light pair, N represents the surface normal vector, represents the transmission refractive index, represents the refractive index of the exiting space, η represents the coefficient of the unit normal vector, and θ represents the incident angle.

[0083] S4. Based on the surface normal vector, construct the initial surface using Poisson's equation.

[0084] The method of constructing the initial surface includes: solving the gradient of the surface normal vector and solving the surface point cloud by Poisson's equation:

[0085]

[0086]

[0087] H=grad(φ)·N

[0088] Where φ represents the surface point cloud, Indicates divergence, grad indicates gradient, n indicates function normal vector, H indicates the current solution value of the equation, and Q indicates the value of divergence twice; when the surface normal vector N is (x, y, -1), the horizontal component of the point cloud gradient is x, and the vertical component of the point cloud gradient is y, that is, φ x =x,φ y =y. Perform vector displacement cycles on the surface point cloud to make the height of the surface center point equal to the position p of the free-form surface, while ensuring the relative height of each surface point. Solve the Poisson equation again until the error is within the error limit, and obtain the initial surface, such as Figure 7 As shown;

[0089] e(x, y)=||φ(x, y)-φ0(x, y)||2>e0

[0090] Wherein, e represents the error function, φ(x, y) represents the surface point cloud of the current cycle, φ0(x, y) represents the surface function of the previous cycle, and e0 represents the error limit. In this embodiment, e0 is 100.

[0091] S5. Perform precise matching on the initial surface to obtain a precise matching light pair.

[0092] The method for obtaining a precisely matched light pair includes: obtaining a point set X' of incident light and a point set T(X') of outgoing light of the initial surface; performing precise matching on the point set X' and the point set T(X'), finding a matching mapping in the point set T(X') that minimizes the cost function, and obtaining a precisely matched light pair:

[0093] min T ∑ X′ c(X′, T(X′))

[0094] c(u,v)=∫(F(u,v)+c0(u,v))dγ(u,v)

[0095] Among them, c(μ, v) represents the cost function of the precise matching, F(u, v) represents the precise matching amount, which represents the change in the optical path difference of the lens, including supplementary operations for single light customization, such as reducing the light intensity in a certain area, and γ(u, v) represents the integral domain mapping function.

[0096] S6. Based on the precise matching of light pairs, a hierarchical optimization method is used to perform global and local optimization to obtain the design surface data of the free-form surface.

[0097] In this embodiment, the optimization operation is performed according to the precise matching light pair, and the optimization is divided into inner and outer layers, the number of inner layers is 10, and the number of outer layers is 10. The outer layer determines the optimization granularity, and the granularity is generally from coarse to fine, from sampling 1000 to sampling 10000. The granularity change is shown in the following formula:

[0098] J n =J0e αt

[0099] Among them, J n represents the change of particle size, J0 represents the initial sampling particle size, α represents the growth coefficient, and t represents the number of cycles; for the outer layer, α=(lnJ n -lnJ0) / 9, J0=1000, J9=10000; for the inner layer, α=(lnJ n -lnJ0) / 9, J0 is determined by the error level when the number of samples is between 50-60, and J9=0.001. After selecting the optimization granularity, the simulation operation is first performed according to Snell's law to obtain the result, and then the error value is obtained according to the target and the result. Then the inner layer uses adaptive error value classification to perform local optimization of the selected block, in which the error level of the region is selected as J n The surface results obtained after optimization are as follows Figure 8 The surface results were imported into Solidworks software. First, the mesh was established using point cloud scanning, and then the 3D surface was reconstructed. The 3D model was established using the “stretch” operation in 3D drawing.

[0100] Embodiment 4

[0101] According to the brand logo of a certain brand of car, the free-form surface design method of the present invention is used to design the microstructure on the free-form surface, and a free-form surface corresponding to the logo pattern is made, and then combined with a light source to make a projection device, wherein the light source can be an LED light source. The projection device can be installed in the vehicle headlight or the surrounding area, or on the door side, etc., to form a welcome light effect, a prompt light effect, or other light effects.

[0102] Embodiment 5

[0103] According to the static graphic advertising design works, the free-form surface design method of the present invention is used to design the microstructure on the free-form surface, and the free-form surface corresponding to the graphic advertising design works is made, and then combined with the light source to make a projection device, wherein the light source can be an LED light source. The projection device can be installed in the lobby, elevator room, and other public areas of the building to form an advertising effect.

[0104] The embodiments described above are only descriptions of the preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. An imaging device based on customized illumination of a free-form surface by light, comprising a light source, characterized in that: It also includes a free-form surface lens. The light source and the free-form surface lens are separately arranged. The light emitted by the light source passes through the free-form surface lens and is directly converged into the required customized pattern lighting.

2. An imaging device based on customized illumination of a free-form surface by light, comprising a light source, characterized in that: It also includes a free-form surface lens, the light source is directly placed on the free-form surface lens, the incident surface of the free-form surface lens is a collimating surface, and the exit surface is a free surface.

3. A free-form surface design method for customized light illumination, the design method being used to design the free-form surface lens according to any one of claims 1 to 2, characterized in that: The following steps are involved: Determine basic optical parameters and target patterns, and sample the incident surface and focal plane, wherein the optical parameters include: transmission refractive index, output space refractive index, focal plane position, lens position, and sampling quantity; Roughly matching the incident light and the outgoing light of the lens to obtain a rough matching light pair; Calculating a surface normal vector of the lens surface using Snell's law according to the roughly matched light pair; Based on the surface normal vector, construct an initial surface using Poisson's equation; Performing precise matching on the initial surface to obtain a precise matching light pair; Based on the precisely matched light pair, a hierarchical optimization method is used to perform global and local optimization to obtain the design surface data of the free-form surface lens.

4. A free-form surface design method for light customized lighting according to claim 3, characterized in that: The sampling method includes: using concentric circle sampling: r l =max(p-p0), Where l represents the number of radial rings sampled, N0 represents the ideal number of samples, S represents the area of ​​the sampled pattern, rl represents the radius of the lth ring from the center of the circle, r1 represents the radius of the first ring from the center of the circle, p represents the free surface position of the sampled pattern in the rectangular coordinate system, p0 represents the center of the pattern, r n represents the radius of the nth ring, c n Indicates the number of samples of the nth ring, N + Represents the set of natural numbers except 0.

5. The free-form surface design method for customized light illumination according to claim 3, characterized in that: The method for obtaining the coarse matching light pair comprises: Obtaining the point set X of the incident light and the point set T(X) of the outgoing light; The point set X and the point set T(X) are roughly matched, and a matching mapping that minimizes the cost function is found in the point set T(X), to obtain the roughly matched light pairs V and V': min T ∑ X c0(X,T(X)) Among them, c0(μ,ν) represents the cost function of coarse matching.

6. A free-form surface design method for customized light illumination according to claim 5, characterized in that: The method for calculating the surface normal vector includes: V′=V+ηN Where V represents the incident light of the coarse matching light pair, V' represents the outgoing light of the coarse matching light pair, N represents the surface normal vector, represents the transmission refractive index, represents the refractive index of the exiting space, η represents the coefficient of the unit normal vector, and θ represents the incident angle.

7. A free-form surface design method for light customized lighting according to claim 6, characterized in that: The method of constructing the initial surface comprises: The surface normal vector is gradient-solved, and the surface point cloud is solved by Poisson's equation: H=grad(φ)·N Where φ represents the surface point cloud, Indicates taking divergence, grad means finding gradient, n means function normal vector, H means the current solution value of the equation, and Q means taking the divergence value twice; Performing a vector displacement cycle on the surface point cloud to make the height of the surface center point equal to the position p of the free-form surface, while ensuring the relative height of each surface point, and solving the Poisson equation again until the error is within the error limit, thereby obtaining the initial surface; e(x, y)=||φ(x, y)-φ0(x, y)||2>e0 Among them, e represents the error function, φ(x, y) represents the surface point cloud of the current cycle, φ0(x, y) represents the surface function of the previous cycle, and e0 represents the error limit.

8. A free-form surface design method for customized light illumination according to claim 7, characterized in that: The method for obtaining the precisely matched light pair comprises: Obtaining a point set X' of incident light rays and a point set T(X') of outgoing light rays of the initial surface; The point set X' and the point set T(X') are precisely matched, and a matching mapping that minimizes the cost function is found in the point set T(X'), to obtain the precisely matched light pair: min T ∑ X′ c(X′,T(X′)) c(u,ν)=∫(F(u,ν)+c0(u,ν))dγ(u,v) Among them, c(μ,ν) represents the cost function of the exact matching, F(u,v) represents the exact matching amount, and γ(u,v) represents the integral domain mapping function.

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