CN115574286B - A free-form surface symbol projection lighting device for vehicles - Google Patents

Abstract

The invention discloses a free-form surface symbol projection lighting device for a vehicle, and belongs to the technical field of non-imaging optics. The lighting device is composed of a lighting source and a free-form surface lens group, wherein the free-form surface lens group comprises a beam collimation free-form surface lens and a free-form surface array lens, and the beam collimation free-form surface lens is used for regulating and controlling the intensity and the wave front of a beam. Light rays emitted by the illumination light source are refracted by the beam collimation free-form surface lens and then become parallel light with uniformly distributed energy, and after being deflected by the free-form surface array lens, a preset symbol illumination light spot is formed on the target surface. The vehicular free-form surface symbol projection lighting device has a simple structure, and the free-form surface lens is smooth and continuous and is easy to process; the device can project high-quality complex light spots, and has the advantages of high energy utilization rate, good projection effect, strong practicability and wide application range.

Description

A free-form surface symbol projection lighting device for vehicles

technical field

The invention relates to the technical field of non-imaging optics and lighting, in particular to a free-form surface symbol projection lighting device for vehicles.

Background technique

With the development of science and technology, smart cars are getting closer and closer to us, and emerging technologies such as smart driving and human-computer interaction have gradually become an important development direction of smart cars. Symbol projection is to project specific symbols at the observation position, which is one of the important directions of human-computer interaction in automobiles. However, the existing automobile pattern projection technology is generally realized directly by blocking the light through the diaphragm, which blocks the propagation of part of the light beam. To achieve pattern projection, this undoubtedly means that a large amount of light source energy is wasted, and it is difficult to achieve a good projection effect when using it.

CN201822024127.3 proposes an illumination optical device for projecting graphic symbols onto a projection surface. The illumination device includes a converging lens and a light-shaping structure. The light-shaping structure is arranged downstream of the converging lens along the projection direction and adjacent to the converging The lens, while the outcoupling surface of the light-shaping structure has a cross-sectional shape corresponding to the graphic symbol, the device homogenizes the light by converging the lens through TIR (TIR = "Total Internal Reflection"), and then through the darkened Pattern projection can be realized by means of the method, and the dark pattern projection method in the device will reduce the utilization rate of light energy, and at the same time, clear boundary and complex pattern projection cannot be realized.

CN201811224209.0 proposes a car lamp projection device that uses a MEMS scanning mirror to reflect the projection beam. The device includes a light source, a beam combining mirror, a shaping cylindrical mirror and a MEMS scanning mirror. The light source generates a projection beam, which is then combined The mirror combines the projection beams in the same direction or different directions into a beam of light, and then reaches the MEMS scanning mirror after passing through the shaped cylindrical mirror. The MEMS scanning mirror rotates according to certain rules to reflect the projection beam and cast it in the projection area A projected pattern. The device needs to use the multi-lens combination and the MEMS scanning mirror to realize the pattern projection, the structure is complex and the scanning accuracy of the scanning device is high.

In order to further improve the application of pattern projection in vehicle lighting and solve the problem of human-computer interaction in smart cars, it is very necessary to propose a symbol projection device with simple structure, high efficiency and energy saving, and good projection effect. Optical free-form surface is a kind of optical surface without axial rotational symmetry or translational symmetry. Its flexible surface structure can break through the traditional optical system concept to create a new structural form, which can greatly simplify the system structure while effectively improving system performance. Reducing the number of optical components can realize a light and small beam control system with high performance and new functions, which has important application value in cutting-edge defense and civilian fields such as high-efficiency energy-saving lighting and laser beam shaping. The free-form surface has great application potential in pattern projection due to its flexible surface structure. Its control principle means that after ignoring the influence of Fresnel reflection, all the light is regulated to the target projection area, improving the projection system. The utility model has great application value in terms of energy utilization, and at the same time, the free-form surface projection device has a simple structure and is convenient for installation and adjustment during use.

Contents of the invention

The object of the present invention is to overcome the deficiencies of the prior art, and provide a free-form surface symbol projection lighting device for vehicles. Technical scheme of the present invention is as follows:

The invention provides a free-form surface symbol projection lighting device for vehicles, which includes an illumination light source and a free-form surface lens group, wherein the free-form surface lens group includes a beam collimating free-form surface lens and a free-form surface array lens sequentially arranged along the optical path; The beam collimating free-form surface lens includes an incident surface and an exit surface, where both the incident surface and the exit surface are free-form surfaces without rotational symmetry; the free-form surface array lens includes an incident surface and an exit surface, where the incident surface is a plane, and the exit surface is The free-form surface has no rotational symmetry; the beam collimating free-form surface lens is used for beam collimation, which deflects the beam emitted by the illumination source into parallel light with uniform light intensity distribution, and vertically illuminates the free-form surface array lens On the incident surface; the parallel light is deflected by the free-form surface array lens to produce a predetermined symbol illumination spot on the target illumination surface;

The outgoing surface of the free-form surface array lens is composed of several identical free-form surface units arranged in a periodic array; the free-form surface unit shapes the parallel light beam with uniform energy distribution into the target pattern illumination distribution, and the free-form surface The optical axis of the unit is parallel to the optical axis of the illumination source, and the incident light beam does not deflect on the incident surface of the free-form surface array lens.

Further, the free-form surface lens group is designed according to the following steps:

1) Initial design of the beam collimating free-form surface lens and free-form surface array lens according to the initial design parameters;

2) According to Snell's law, the law of energy conservation and the principle of equal optical path, the beam collimating free-form surface lens is designed, and the outgoing beam of the illumination source is shaped into a parallel light with uniform light intensity distribution, and the light beam collimating the free-form surface lens The axis coincides with the optical axis of the illumination source;

3) Design the freeform surface array lens according to the law of energy conservation and Snell's law;

4) Model the beam collimating free-form surface lens and the free-form surface array lens to obtain the free-form surface lens group.

Furthermore, the design of the free-form surface array lens includes the following steps:

3.1) The size of the free-form surface array lens is k*k, which contains m*m identical free-form surface lens units, m is an integer greater than 1, and the aperture of each free-form surface lens unit is k/m;

3.2) Establish the energy conservation relation:

,

Among them, I(x,y) is the intensity distribution of the light source, where I(x,y) is a uniform illumination beam with a square distribution, the beam aperture size is k/m, E(t _x , _ty ) is the target illumination The illuminance distribution of the target illumination area on the surface, that is, the final target illuminance distribution, J(T) is the Jacobi matrix of the position vector T, ;

3.3) Simplify the above formula to get the equation:

Among them, z _xx and z _yy are the second-order partial derivatives of the coordinate z of point P with respect to x and y , z _xy is the second-order mixed partial derivative of coordinate z of point P with respect to x and y , and the coefficients B _i are expressed as z _x , z _y , z , x and y functions, where B ₁ is the coefficient equation of z _xx z _yy -z _xy ² terms, B ₂ is the coefficient equation of z _xx term, B ₃ is the coefficient equation of z _yy term, B ₄ is the coefficient equation of _{the zxy} term , B5 is the constant term equation, and _the internal light of the incident beam should satisfy the above energy transfer equation;

3.4) Establish boundary conditions;

3.5) The above energy transfer equation and boundary conditions are solved simultaneously to obtain a set of discrete data points, and the surface shape of the required free-form surface unit can be obtained by surface fitting the set of data points.

The beneficial effect that the present invention has compared with prior art is:

1) The present invention adopts the free-form surface beam control technology, which overcomes the technical problems that it is difficult to realize fine pattern projection and the pattern boundary is blurred in the prior art, so as to obtain a fine and complex projection pattern with sharp boundaries.

2) The present invention overcomes the problem of beam energy waste in the prior art. The present invention can distribute all incident light energy to the target pattern under the condition of ignoring Fresnel reflection, and has a high energy utilization rate.

3) The present invention uses a free-form surface array lens as the pattern projection lens, which overcomes the problems of high alignment accuracy and difficult installation and adjustment in the prior art. In the present invention, each array unit in the free-form surface array lens can A predetermined pattern projection is generated on the target lighting surface, so the uniformity of the light beam reaching the array lens is not high, so the installation and adjustment error tolerance of the system is high, and the installation and adjustment are convenient.

4) The present invention adopts a free-form surface lens as a light beam collimating lens, which overcomes the requirement of the rotational symmetry of the light source in the prior art. The illumination light source of the present invention can be an LED light source, or a larger power source with other light intensities Distributed non-rotationally symmetric light sources.

Description of drawings

Fig. 1 is a structural diagram of the optical path of the free-form surface symbol projection lighting device for vehicles according to the present invention.

Fig. 2 is a schematic structural view of the beam collimating free-form surface lens of the present invention.

FIG. 3 is a schematic diagram of the structure of the free-form surface array lens of the present invention.

Fig. 4 is a schematic diagram of the structure of the free-form surface lens group of the present invention.

Fig. 5 is a diagram of the ray tracing result of the beam collimating free-form surface lens.

Fig. 6 is a ray tracing result diagram of the free-form surface lens group.

In the figure, 1-illumination light source; 2-beam collimation free-form surface lens; 3-free-form surface array lens; 4-free-form surface lens group; 5-first incident surface; 6-first exit surface; 7-second incident surface; 8-the second exit surface.

Detailed ways

In order to make the purpose of the present invention, technical solutions and advantages clearer, it will be further described below in conjunction with the accompanying drawings. curved lens and a freeform array lens for pattern projection.

As shown in Figures 1 to 4, the embodiment of the present invention provides a vehicle free-form surface symbol projection lighting device; the projection device includes an illumination light source 1 and a free-form surface lens group 4, wherein the free-form surface lens group 4 includes a beam collimating free-form surface lens 2 and the free-form surface array lens 3; the light beam from the illumination source 1 is deflected by the light beam collimating free-form surface lens 2 to become a parallel light with uniform illumination intensity distribution, and the parallel light is deflected by the free-form surface array lens 3 again before the target illumination Directional lighting distribution is generated on the surface, see Figure 1.

The beam collimating free-form surface lens 2 of this embodiment includes a first incident surface 5 and a first exit surface 6 , wherein both the first incident surface 5 and the first exit surface 6 are free-form surfaces without rotational symmetry. The beam collimation free-form surface lens 2 is used for beam collimation, which deflects the beam emitted by the illumination source into parallel light with uniform light intensity distribution, and irradiates the incident surface of the free-form surface array lens 3 vertically.

The free-form surface array lens 3 of the present embodiment includes a second incident surface 7 and a second exit surface 8, wherein the second incident surface 7 is a plane, and the second exit surface 8 is a free-form surface and does not have rotational symmetry; After the deflection of the free-form surface array lens 3, a predetermined symbol illumination spot is produced on the target illumination surface; the exit surface of the free-form surface array lens is composed of several identical free-form surface units arranged in a periodic array; the free-form surface array lens The curved surface unit shapes the parallel light beam with uniform energy distribution into the target pattern illumination distribution, the optical axis of the free curved surface unit is parallel to the optical axis of the illumination light source, and the incident light beam does not deflect on the incident surface of the free curved surface array lens.

In the present embodiment, the design method of the free-form surface lens group 4 is as follows:

(1) Design of beam collimating free-form surface lens 2

Design the beam collimating free-form surface lens and the free-form surface array lens according to the initial design parameters; design the beam collimating free-form surface lens according to Snell's law, the law of energy conservation and the principle of equal optical path, and shape the outgoing beam of the illumination source into light Parallel light with strong distribution and uniformity, the optical axis of the beam collimating free-form surface lens coincides with the optical axis of the illumination source.

(2) Design of free-form surface array lens 3

According to the law of energy conservation and Snell's law, the free-form surface array lens is designed, and the exit surface of the free-form surface array lens is composed of a number of free-form surface units arranged in an array; the free-form surface unit shapes parallel beams with uniform energy distribution Illumination distribution of the target pattern, the optical axis of the free-form surface unit is parallel to the optical axis of the illumination source, and the incident surface of the free-form surface array lens is a plane, which does not deflect the incident light beam.

(3) Model the beam collimating free-form surface lens and the free-form surface array lens to obtain the free-form surface lens group.

Embodiment: the light source is a white LED with Lambertian light intensity distribution, the luminous intensity distribution satisfies I(φ)=cosφ, the height of the lighting device is 10mm, that is, the distance between the incident LED light source and the exit surface of the optical system is 10mm, and the projection distance is 500mm, that is, the distance between the light source and the target projection surface is 500mm, the size of the projection pattern is 300*300mm, and the illumination ratio of the pattern to the background is 2.5:1. In this embodiment, the projection pattern is the letter "ZJ1". According to different application requirements, the projection pattern can be changed flexibly. The refractive index of the material used in the prefix curved surface lens group is 1.4936, the medium around the lens is air, the total length of the free curved surface lens group is less than 10mm, and the aperture size is 4mm.

The design of the beam collimating free-form surface lens 2 of the present embodiment is as follows:

According to Snell's law, the law of energy conservation and the principle of equal optical path, the free-form surface lens for beam collimation is designed to shape the outgoing beam of the illumination source into parallel light with uniform light intensity distribution, and the beam collimation free-form surface lens The optical axis coincides with the optical axis of the illumination source;

Establish the energy conservation relation:

in, is the intensity distribution of the illumination source, is the target illuminance distribution on the incident surface of the curved surface array lens, J(T) is the Jacobi matrix of the position vector T, is the azimuth in polar coordinates, is the polar angle; , ,in is the maximum divergence angle of the beam incident on the beam collimating free-form surface lens.

Establish the equal optical path principle relation: OPL=|OP|+n|PQ|+|QT|, where OPL is the optical path of a certain light from the light source to a certain wavefront, and |OP| is the optical path of the light from the light source The distance between the starting surface and the incident surface of the free-form surface, |PQ| is the distance between the intersection point of the ray on the incident surface and the exit surface of the free-form surface, |QT| is the intersection point of the ray on the exit surface and a certain wavefront Distance, n is the refractive index of the lens material, n=1.49386.

Simultaneously combine the above energy conservation relational formula and the equal optical path principle relational formula to obtain the following second-order nonlinear partial differential equation

Among them, r is the distance between the light falling on the incident surface and the exit surface of the beam collimating free-form surface lens, is the azimuth in polar coordinates, is the polar angle, , r in and The first-order partial derivative of the direction, , r in and The second order partial derivative of the direction, is r in and The second order mixed partial derivatives in both directions, A _i is , , r , as well as function of i=1,...,5, where A ₁ is The coefficient equation of the term, A ₂ is The coefficient equation of the term, A ₃ is The coefficient equation of the term, A ₄ is The coefficient equation of the term, A ₅ is the constant term equation.

Establish boundary conditions:

in, Indicates the range of the beam incident on the free-form surface, Indicates the illuminated area on the incident surface of the curved array lens, and area respectively and borders.

Using the difference substitution differential method and the Newton iterative method to solve the above second-order nonlinear partial differential equation and boundary conditions simultaneously, a set of discrete data points is obtained, and the required free-form surface element can be obtained by surface fitting the set of data points face shape.

The design of the freeform surface array lens 3 of the present embodiment is as follows:

According to the law of energy conservation and Snell's law, the free-form surface array lens is designed, and the free-form surface array lens is composed of 16 identical free-form surface units arranged in arrays along two mutually perpendicular directions; the free-form surface array The free-form surface unit in the module shapes the parallel light beam with uniform energy distribution into the target pattern illumination distribution. The optical axis of the free-form surface unit is parallel to the optical axis of the illumination source, and the incident surface of the free-form surface array lens is a plane. There is no deflection of the beam, and the exit surface is a free-form surface;

The energy conservation relation is established. Without considering the energy loss, all the energy of any thin light beam emitted by the light source is deflected by the free-form surface lens and then transmitted to the target illumination area on the illumination surface, that is, the free-form surface is to the thin light beam. The deflection of the beam satisfies the following energy relation , where, I(x,y) is the intensity distribution of the light source; E(t _x , _ty ) is the illuminance distribution of the target lighting area on the target lighting surface, here is the letter "ZJU", J(T) is the Jacobi matrix of the position vector T, ;

Simplify the above formula to get the equation:

Among them, z _xx and z _yy are the second-order partial derivatives of the coordinate z of point P with respect to x and y , z _xy is the second-order mixed partial derivative of coordinate z of point P with respect to x and y , and the coefficients B _i are expressed as z _x , z _y , z , x and y functions, where B ₁ is the coefficient equation of z _xx z _yy -z _xy ² terms, B ₂ is the coefficient equation of z _xx term, B ₃ is the coefficient equation of z _yy term, B ₄ is the coefficient equation of the z _{x xy} term, B ₅ is the constant term equation, and the internal light of the incident beam should satisfy the above energy transfer equation.

While the free-form surface satisfies the above energy transfer equation, it must also ensure that the boundary light of the beam is incident on the boundary of the target illumination area after being deflected by the free-form surface, that is, the following boundary conditions are met

in, Indicates the range of the outgoing beam of the beam collimating free-form surface lens, that is, the range of the beam incident on the free-form surface array lens, Indicates the illuminated area on the target illuminated surface, and area respectively and borders.

Solve the above energy transfer equation and boundary conditions simultaneously to obtain a set of discrete data points, and then perform surface fitting on the set of data points to obtain the required surface shape of the free-form surface unit.

Model the collimating free-form surface lens and the free-form surface array lens to obtain the free-form surface lens projection module, see attached drawings 2, 3 and 4, wherein attached drawing 2 is a free-form surface used for beam collimation and homogenization Lens 2, Figure 3 is a free-form surface array lens 3 that produces symbol projection, and Figure 4 is the overall model of the free-form surface symbol projection lighting device for vehicles. The first incident surface 5 and the first exit surface 6 of the beam collimating free-form surface lens 2 are free-form surfaces without rotational symmetry; the second incident surface 7 of the free-form surface array lens 3 is a plane, and the second exit surface 8 is The free-form surface is composed of 4*4 free-form surface unit arrays, and the exit surface does not have rotational symmetry; the beam collimating free-form surface lens 2 deflects the beam emitted by the illumination source into parallel light with uniform light intensity distribution, And vertically illuminate the incident surface of the free-form surface array lens 3, and the parallel light is deflected by the free-form surface array lens 3 to produce a predetermined "ZJU" symbol illumination spot on the target illumination surface.

Perform ray tracing on the collimated free-form surface lens, and obtain the illuminance distribution of the outgoing light at any plane, as shown in Figure 5. From Figure 5, it can be seen that the light beam with Lambertian distribution is shaped after passing through the collimated free-form surface lens 2 It is a uniform square spot and a parallel collimated beam. The free-form surface lens group model is used to trace light rays, and the illuminance distribution diagram obtained on the target lighting surface is shown in Figure 6. From Figure 6, it can be seen that the incident light beam is shaped by the symbol projection lighting device proposed by the present invention and becomes a light beam on the target surface. Pattern distribution of "ZJU" letter style. The illuminance distribution diagram clearly shows that the free-form surface symbol projection lighting device for vehicles proposed by the present invention meets the target lighting requirements, and effectively simulates a uniform lighting spot with a clear boundary illuminated by natural light.

The above-mentioned embodiments only express several implementation modes of the present invention, and the description thereof is relatively specific and detailed, but should not be construed as limiting the patent scope of the present invention. For those skilled in the art, without departing from the concept of the present invention, several modifications and improvements can be made, and these all belong to the protection scope of the present invention.

Claims (7)

1. A vehicle free-form surface symbol projection lighting device is characterized in that it comprises an illumination light source and a free-form surface lens group, wherein the free-form surface lens group comprises a light beam collimating free-form surface lens and a free-form surface array lens arranged in sequence along the optical path ; The free-form surface lens for beam collimation includes an incident surface and an exit surface, wherein both the incident surface and the exit surface are free-form surfaces without rotational symmetry; the free-form surface array lens includes an incident surface and an exit surface, wherein the entrance surface is a plane, and the exit surface It is a free-form surface and does not have rotational symmetry; the beam collimating free-form surface lens is used for beam collimation, which deflects the beam emitted by the illumination source into parallel light with uniform light intensity distribution, and irradiates the free-form surface array lens vertically The incident surface; the parallel light is deflected by the free-form surface array lens to generate a predetermined symbol illumination spot on the target illumination surface; The outgoing surface of the free-form surface array lens is composed of several identical free-form surface units arranged in a periodic array; the free-form surface unit shapes the parallel light beam with uniform energy distribution into the target pattern illumination distribution, and the free-form surface The optical axis of the unit is parallel to the optical axis of the illumination source, and the incident light beam on the incident surface of the free-form surface array lens does not deflect; The free-form surface lens group is designed according to the following steps: 1) Initial design of the beam collimating free-form surface lens and free-form surface array lens according to the initial design parameters; 2) According to Snell's law, the law of energy conservation and the principle of equal optical path, the beam collimating free-form surface lens is designed, and the outgoing beam of the illumination source is shaped into a parallel light with uniform light intensity distribution, and the light beam collimating the free-form surface lens The axis coincides with the optical axis of the illumination source; The step 2) includes the following steps: 2.1) Establish the energy conservation relation: in, is the intensity distribution of the illumination source, is the target illuminance distribution on the incident surface of the curved surface array lens, J(T) is the Jacobi matrix of the position vector T, is the azimuth in polar coordinates, is the polar angle; , ,in is the maximum divergence angle of the beam incident on the beam collimating free-form surface lens; 2.2) Establish the relational formula of equal optical path principle; 2.3) The following second-order nonlinear partial differential equation is obtained by combining the energy conservation relational formula and the equal optical path principle relational formula: Among them, r is the distance between the light falling on the incident surface and the exit surface of the beam collimating free-form surface lens, is the azimuth in polar coordinates, is the polar angle, , r in and The first-order partial derivative of the direction, , r in and The second order partial derivative of the direction, is r in and The second order mixed partial derivatives in both directions, A _i is , , r , as well as function of i=1,...,5, where A ₁ is The coefficient equation of the term, A ₂ is The coefficient equation of the term, A ₃ is The coefficient equation of the term, A ₄ is The coefficient equation of the term, A ₅ is the constant term equation; 2.4) Establish boundary conditions; 2.5) Solve the second-order nonlinear partial differential equation and boundary conditions simultaneously by using the differential substitution differential method and the Newton iterative method to obtain a set of discrete data points, and obtain the required beam collimation freedom by surface fitting the set of data points Surface type of curved lens; 3) Design the freeform surface array lens according to the law of energy conservation and Snell's law; 4) Model the beam collimating free-form surface lens and the free-form surface array lens to obtain the free-form surface lens group. 2. The vehicle-used free-form surface symbol projection lighting device according to claim 1, characterized in that, the equal optical path principle relation in step 2.2) is: OPL=|OP|+n|PQ|+|QT| Among them, OPL is the optical path of a certain ray from the light source to a certain wavefront, |OP| is the distance between the ray starting from the illumination source and the incident surface of the beam collimating free-form surface lens, |PQ| is the distance of the ray at The distance between the intersection point between the incident surface and the exit surface of the beam collimating free-form surface lens, |QT| is the distance between the intersection point of the light on the exit surface and a certain wavefront, and n is the refractive index of the lens material. 3. The free-form surface symbol projection lighting device for vehicles according to claim 1, wherein the boundary conditions in the step 2.4) are: in, Indicates the range of the beam incident on the free-form surface, Indicates the illuminated area on the incident surface of the curved array lens, and area respectively and borders. 4. The vehicle free-form surface symbol projection lighting device according to claim 1, wherein the design method of the free-form surface array lens comprises the following steps: 3.1) The size of the free-form surface array lens is k*k, which contains m*m identical free-form surface lens units, m is an integer greater than 1, and the aperture of each free-form surface lens unit is k/m; 3.2) Establish the energy conservation relation: Among them, I(x, y) is the intensity distribution of the light source, where I(x, y) is a uniform illumination beam with a square distribution, the beam aperture size is k/m, E(t _x , _ty ) is the target illumination The illuminance distribution of the target illumination area on the surface, that is, the final target illuminance distribution, J(T) is the Jacobi matrix of the position vector T, ; 3.3) Simplify the above formula to get the equation: Among them, z _xx and z _yy are the second-order partial derivatives of the coordinate z of point P with respect to x and y , z _xy is the second-order mixed partial derivative of coordinate z of point P with respect to x and y , and the coefficients B _i are expressed as z _x , z _y , z , x and y functions, where B ₁ is the coefficient equation of z _xx z _yy -z _xy ² terms, B ₂ is the coefficient equation of z _xx term, B ₃ is the coefficient equation of z _yy term, B ₄ is the coefficient equation of _{the zxy} term , B5 is the constant term equation, and _the internal light of the incident beam should satisfy the above energy transfer equation; 3.4) Establish boundary conditions; 3.5) The above energy transfer equation and boundary conditions are solved simultaneously to obtain a set of discrete data points, and the surface shape of the required free-form surface unit can be obtained by surface fitting the set of data points. 5 . The free-form surface sign projection lighting device for vehicles according to claim 4 , wherein the target illuminance distribution in step 3.2) is uniform distribution, pattern distribution or other illuminance distribution specified by the user. 6 . 6. The vehicle free-form surface symbol projection lighting device according to claim 4, characterized in that the boundary conditions in step 3.4 are: in, Indicates the range of the outgoing beam of the beam collimating free-form surface lens, that is, the range of the beam incident on the free-form surface array lens, Indicates the illuminated area on the target illuminated surface, and area respectively and borders. 7 . The free-form surface symbol projection lighting device for vehicles according to claim 1 , wherein the lighting light source is a white LED light source or a laser diode light source. 8 .

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