CN203363990U - Free-form surface microlens array for LED (Light-Emitting Diode) automotive headlamp - Google Patents

Abstract

The utility model discloses a free-form surface microlens array for an LED (Light-Emitting Diode) automotive headlamp. Light emitted from an LED light source in the LED automotive headlamp is collimated and then emitted in a parallel-beam manner; the free-form surface microlens array is formed by compactly arraying a plurality of free-form surface microlenses and fully distributing the free-form surface microlenses on the integral section of the parallel beams; all the free-form surface microlenses are integrally formed; the incident faces of the free-form surface microlenses are planes, and the light-emitting faces of the free-form surface microlenses are free-form surfaces. The free-form surface microlens array disclosed by the utility model carries out light distribution without using a light baffle, thereby reducing the loss on light energy caused by a light distribution system and increasing the utilization ratio of the light energy; the free-form surface microlens array disclosed by the utility model adopts the free-form surface optical design, thereby effectively controlling the light ray trend, inhibiting the glare effect and meeting the requirement of the national standard GB25991-2010 on the light distribution of the automotive LED headlamp.

Description

The free curved surface micro-lens array that a kind of LED car headlamp is used

Technical field

The utility model relates to LED Illuminating Technique for Headlamp field, particularly for the freeform optics microlens array of LED car headlamp.

Background technology

LED light source is a kind of new and effective light source, according to research, shows, LED has the irreplaceable superior function of other light source, can be car headlamp and opens up huge application space.Especially LED light source has small and exquisite, firm, long-lived, energy-conservation, complanation, is applicable to the plurality of advantages such as electromechanical intellectuality, has met that people are safe, comfortable, luxurious to car headlamp, the requirement of energy-saving and environmental protection and the aspect such as multi-functional.These characteristics make LED light source become a focus of competitively researching and developing at present both at home and abroad.

Due to LED, than other light sources, the characteristics of luminescence has very large difference, and arranging of chip array all can have influence on final effect with the design of fitting structure, will face more complicated optical design problem while making LED light source be applied to motorcycle headlamp.At present, use to such an extent that be the design of projection-type LED headlamp more widely, this optical design can form good light type effect, but also needs to add light barrier when dipped headlights designs, whole optical system complexity, and the efficiency of light energy utilization is lower.

The utility model content

The utility model is for the problem of above-mentioned existence, the free curved surface micro-lens array that provides the LED car headlamp to use, the light that this freeform optics microlens array sends LED chip carries out luminous intensity distribution after collimation, the light type produced can meet the light distribution requirements of standard GB/T 25991-2010 to the vapour Vehicular LED headlamp, and do not need light barrier, solved the lower problem of the projection-type LED headlamp design efficiency of light energy utilization.The utility model adopts following technical scheme:

The free curved surface micro-lens array that the LED car headlamp is used, the light that in the LED car headlamp, LED light source sends penetrates with collimated light beam after collimation, and described free curved surface micro-lens array is covered with the section constitution of whole described collimated light beam by several free form surface lenticule compact arrangement.

Further improved, all free form surface lenticules are formed as one.

Further improved, the lenticular plane of incidence of described free form surface is plane, and exit facet is free form surface.

Further improved, the lenticular plane of incidence of described free form surface is rectangle plane.

Further improved, the lenticular exit facet of described free form surface is that free form surface is determined as follows:

The light that LED light source sends penetrates with collimated light beam after collimation, choose a micro rectangle zone in the cross section of this light beam, this micro rectangle zone is long is a, wide is b, illumination in this micro rectangle zone is considered as equiluminous, light in this micro rectangle district forms an isolux hot spot through lens on illuminated area, according to law of conservation of energy, has:

E _o·S _o＝E _v·S _v，

E _omean the brightness value of outgoing collimated light beam in the micro rectangle district, S _othe area that means this micro rectangle district; E _vthe brightness value that means hot spot on illuminated area, S _vthe area that means this hot spot, E _vbe expressed as:

E _v＝E _o·t，

The area S that in formula, t is the micro rectangle zone _oarea S with hot spot _vratio;

Then, according to the light distribution requirements to the LED car headlamp, to form a non-isolux hot spot on illuminated area, the optical axis that makes whole LED car headlamp is the z axle, and the xoy plane is illuminated area so, and the grid division is carried out in field of illumination, evenly be divided into the m row on the direction of x axle, evenly be divided into n capable on the direction of y axle, each little lattice is numbered, wherein i is listed as the G that is numbered of the capable little lattice of j _{(i, j)}, on illuminated area, the energy of i row is:

$Q_{(i,0)}=\underset{j=1}{\overset{n}{\mathrm{\Σ}}}{E}_v\·k_{(i,j)}\·S_{(i,j)},$

Simultaneously, above-mentioned equation will meet:

$E_v\·S_v=\underset{i=1}{\overset{m}{\mathrm{\Σ}}}{Q}_{(i,0)},$

Above in two formulas, S _{(i, j)}mean G on illuminated area _{(i, j)}area; According to the light distribution requirements of LED car headlamp, illumination controlling elements k is set _{(i, j)}control the brightness value size of appointed area on illuminated area, the Illumination Distribution met the demands in order to formation, E _vk _{(i, j)}mean G on illuminated area _{(i, j)}brightness value, k _{(i, j)}the value size according to illumination requirement on illuminated area, set, the larger regional k for illumination _{(i, j)}value larger, the less regional k for illumination _{(i, j)}value less;

The energy that on illuminated area, j is capable is:

$Q_{(0,j)}=\underset{i=1}{\overset{m}{\mathrm{\Σ}}}{E}_v\·k_{(i,j)}\·S_{(i,j)},$

Simultaneously, above-mentioned equation will meet:

$E_v\·S_v=\underset{j=1}{\overset{n}{\mathrm{\Σ}}}{Q}_{(0,j)},$

Then corresponding to the grid on illuminated area, divide, by law of conservation of energy, the grid division is carried out in the micro rectangle zone of outgoing collimated light beam, at first this micro rectangle zone is listed as to division, Energy distribution corresponding to i row on illuminated area, according to law of conservation of energy, the energy of these micro rectangle zone i row is:

E _o·b·p _i＝Q _(i,0)，

In formula, p _ifor the width of these micro rectangle zone i row, combine above-mentioned a few formula and can solve p _i;

In like manner, division is gone in this micro rectangle zone, according to law of conservation of energy, j capable energy in this rectangle zonule is:

E _o·a·q _j＝Q _(0,j)，

In formula, q _jfor the capable width of this micro rectangle zone j, combine above-mentioned a few formula and can solve q _j; By these two p that equation calculates _iand q _jthe grid that completes this micro rectangle zone is divided, same, and each little lattice is numbered, and i is listed as the g that is numbered of the capable little lattice of j _{(i, j)};

Finally, according to the grid in field of illumination and beam cross section micro rectangle zone, divide, utilize the law of refraction to calculate lenticular free form surface.Lenticule carries out luminous intensity distribution to the light that incides the micro rectangle zone, makes on illuminated area to form the hot spot that meets lighting criteria, g in the micro rectangle zone _{(i, j)}with G on illuminated area _{(i, j)}corresponding.

This free form surface is made as to lenticular exit facet, make the lenticule that a plane of incidence is plane, to several, such lenticule carries out array arrangement again, arrangement is covered with the cross section of whole incident collimated light beam, and be combined into an entity, can obtain the free curved surface micro-lens array that the LED car headlamp is used.

Compared with prior art, the utlity model has following advantage and technique effect: the utility model provides LED car headlamp free curved surface micro-lens array, the light that this freeform optics microlens array sends LED chip carries out luminous intensity distribution after collimation, do not need light barrier to carry out luminous intensity distribution, reduce the loss of light distributing system to luminous energy, improved the efficiency of light energy utilization; The design of employing freeform optics, can effectively control the light trend, suppress glare effect, the light distribution requirements of GB25991-2010 to the vapour Vehicular LED headlamp can be up to state standards again simultaneously, and each lenticule of free curved surface micro-lens array is independently, and can form the hot spot of various shape, design flexibility is high.

The accompanying drawing explanation

The luminous intensity distribution principle schematic that Fig. 1 is LED car headlamp in embodiment.

The parabolic reflector collimater schematic diagram that Fig. 2 a is LED car headlamp in embodiment;

The total reflection lens collimater schematic diagram that Fig. 2 b is LED car headlamp in embodiment.

The field of illumination grid that Fig. 3 is dipped headlights in embodiment is divided schematic diagram.

Fig. 4 is that in embodiment, the micro rectangle area grid in collimated light beam is divided schematic diagram.

The corresponding schematic diagram of the energy that Fig. 5 is field of illumination and micro rectangle zone in embodiment.

The schematic diagram that Fig. 6 is lenticule free form surface in embodiment.

Fig. 7 a, Fig. 7 b are respectively the schematic three dimensional views of two kinds of different visual angles of lenticule entity in embodiment.

The schematic three dimensional views that Fig. 8 is free curved surface micro-lens array in embodiment.

The specific embodiment

Below in conjunction with the drawings and specific embodiments, the utility model is described in further detail.

The freeform optics microlens array 100 luminous intensity distribution principles that the LED car headlamp that the utility model provides is used are (in figure, arrow means the direction of light beam) as shown in Figure 1.Because standard GB/T 25991-2010 has carried out light distribution requirements to dipped beam and the distance light of LED car headlamp, more harsh to the requirement of dipped beam especially, this specific embodiment describes with the example that is designed to of dipped beam.

At first, the light that LED light source the sends processing that will collimate, the effect of collimation can reach by modes such as reflection or refractions, and as shown in Fig. 2 a, Fig. 2 b, light penetrates with collimated light beam after collimation.

Then, the grid division is carried out in field of illumination, as shown in Figure 3.Light distribution requirements according to standard GB/T 25991-2010 to the LED automobile headlight low beam, will form a non-isolux asymmetric hot spot on illuminated area.The optical axis of first setting whole optical system is the z axle, and the xoy plane is illuminated area so.The grid division is carried out in field of illumination, evenly be divided into the m row on the direction of x axle, evenly be divided into n capable on the direction of y axle, each little lattice is numbered, for example i is listed as the G that is numbered of the capable little lattice of j _{(i, j)}.Certainly, grid is divided littlely, and the numerical value of m and n is larger, and the precision of calculating can be higher.On illuminated area, the energy of i row is:

$Q_{(i,0)}=\underset{j=1}{\overset{n}{\mathrm{\Σ}}}{E}_v\·k_{(i,j)}\·S_{(i,j)}$

Simultaneously, above-mentioned equation will meet:

$E_v\·S_v=\underset{i=1}{\overset{m}{\mathrm{\Σ}}}{Q}_{(i,0)}$

Above in two formulas, E _vthe average illumination value that means hot spot on illuminated area, S _vthe area that means this hot spot, S _{(i, j)}mean G on illuminated area _{(i, j)}area; According to standard GB/T 25991-2010, illumination controlling elements k is set _{(i, j)}control the brightness value size of appointed area on illuminated area, meet the Illumination Distribution of standard in order to formation, E _vk _{(i, j)}mean G on illuminated area _{(i, j)}brightness value, k _{(i, j)}the value size need be set according to illumination requirement on illuminated area, as the regional k larger for illumination _{(i, j)}value larger, the less regional k for illumination _{(i, j)}value less.

In like manner, the energy that on illuminated area, j is capable is:

$Q_{(0,j)}=\underset{i=1}{\overset{m}{\mathrm{\Σ}}}{E}_v\·k_{(i,j)}\·S_{(i,j)}$

Simultaneously, above-mentioned equation will meet:

$E_v\·S_v=\underset{j=1}{\overset{n}{\mathrm{\Σ}}}{Q}_{(0,j)}$

Then, corresponding to the grid on illuminated area, divide, by law of conservation of energy, the grid division carried out in a zonule of incident collimated light beam, calculate for convenient, this zonule be set as long for a(as 8mm), wide is that b(is as 4mm) rectangle.Calculated the grid in this micro rectangle zone divides according to energy conservation relation.For example, corresponding to the Energy distribution of i row on illuminated area, according to law of conservation of energy, the energy of these micro rectangle zone i row is:

E _o·b·p _i＝Q _(i,0)

In formula, E _omean the brightness value in a certain zonule of outgoing collimated light beam, p _ifor the width of these micro rectangle zone i row, combine above-mentioned a few formula and can solve p _i.

In like manner, to being gone division in this micro rectangle zone, according to law of conservation of energy, the capable energy of this micro rectangle zone j is:

E _o·a·q _j＝Q _(0,j)

In formula, q _jfor the capable width of this micro rectangle zone j, combine above-mentioned a few formula and can solve q _j.By these two p that equation calculates _iand q _jthe grid that can complete this micro rectangle zone is divided.Same, each little lattice is numbered, for example i is listed as the g that is numbered of the capable little lattice of j _{(i, j)}, as shown in Figure 4, the scope that wherein dotted border is the incident collimated light beam.

Finally, divide according to the grid in field of illumination and micro rectangle zone, can utilize the law of refraction to calculate lenticular free form surface, lenticule carries out luminous intensity distribution to the light that incides the micro rectangle zone, make on illuminated area to form the hot spot that meets lighting criteria, g in the micro rectangle zone _{(i, j)}with G on illuminated area _{(i, j)}corresponding, as shown in Figure 5.

When iterative computation, at first need to determine the starting point of a calculating, for example, with g in the micro rectangle zone _(1,1)central point be starting point, g _(1,1)g on corresponding illuminated area _(1,1), pass through g _(1,1)the coordinate of central point and G _(1,1)the coordinate of central point can obtain the direction vector of emergent ray, utilizes the law of refraction to calculate and can draw g _(1,1)the normal vector of central point, thus determine the ，Gai section, section of this point and incide g _(1,2)thereby the ray intersection of central point is determined next calculation level, by coordinate and the G of this calculation level _(1,2)the coordinate of central point can obtain the direction vector of next emergent ray, obtain the section of this point and next calculation level again by above-mentioned computational methods again, by that analogy, can draw the coordinate of all calculation levels by computer iterations, can fit to lenticular free form surface 1011 by these a series of calculation levels, as shown in Figure 6.

This free form surface 1011 is made as to lenticular exit facet, makes the lenticule 101 that a plane of incidence is plane 1012, as shown in Fig. 7 a, Fig. 7 b.This lenticule is carried out to array arrangement, arrange and be covered with the cross section of whole incident collimated light beam, and be combined into a physical model, can obtain the free curved surface micro-lens array 100 that the LED car headlamp is used, as shown in Figure 8.

Above LED car headlamp provided by the utility model is described in detail with free curved surface micro-lens array, the light that this freeform optics microlens array sends LED chip carries out luminous intensity distribution after collimation, do not need light barrier to carry out luminous intensity distribution, reduced the loss of light distributing system to luminous energy, improved the efficiency of light energy utilization, luminous intensity distribution performance is good; The design of employing freeform optics, can effectively control the light trend, suppress glare effect, the light distribution requirements of GB25991-2010 to the vapour Vehicular LED headlamp can be up to state standards again simultaneously, and each lenticule of free curved surface micro-lens array is independently, and can form the hot spot of various shape, design flexibility is high.Apply various illustratons of model in the utility model the specific embodiment has been set forth, the foregoing is only the better feasible examples of implementation of the utility model.For those skilled in the art, according to thought of the present utility model, all can be improved part in specific embodiments and applications.In sum, this description should not be construed as restriction of the present utility model.

Claims (5)

1. the free curved surface micro-lens array that the LED car headlamp is used, the light that in the LED car headlamp, LED light source sends penetrates with collimated light beam after collimation, it is characterized in that, described free curved surface micro-lens array is covered with the section constitution of whole described collimated light beam by several free form surface lenticule compact arrangement.

2. the free curved surface micro-lens array that LED car headlamp according to claim 1 is used, is characterized in that all free form surface lenticules are formed as one.

3. the free curved surface micro-lens array that LED car headlamp according to claim 1 is used, is characterized in that the lenticular plane of incidence of described free form surface is plane, and exit facet is free form surface.

4. the free curved surface micro-lens array that LED car headlamp according to claim 3 is used, is characterized in that the lenticular plane of incidence of described free form surface is rectangle plane.

5. the free curved surface micro-lens array that LED car headlamp according to claim 4 is used is characterized in that the lenticular exit facet of described free form surface is that free form surface is determined as follows:

The light that LED light source sends penetrates with collimated light beam after collimation, choose a micro rectangle zone in the cross section of this light beam, this micro rectangle zone is long is a, wide is b, illumination in this micro rectangle zone is considered as equiluminous, light in this micro rectangle district forms an isolux hot spot through lens on illuminated area, according to law of conservation of energy, has:

E _o·S _o＝E _v·S _v，

E _omean the brightness value of outgoing collimated light beam in the micro rectangle district, S _othe area that means this micro rectangle district; E _vthe brightness value that means hot spot on illuminated area, S _vthe area that means this hot spot, E _vbe expressed as:

E _v＝E _o·t，

The area S that in formula, t is the micro rectangle zone _oarea S with hot spot _vratio;

Then, according to the light distribution requirements to the LED car headlamp, to form a non-isolux hot spot on illuminated area, the optical axis that makes whole LED car headlamp is the z axle, and the xoy plane is illuminated area so, and the grid division is carried out in field of illumination, evenly be divided into the m row on the direction of x axle, evenly be divided into n capable on the direction of y axle, each little lattice is numbered, wherein i is listed as the G that is numbered of the capable little lattice of j _{(i, j)}, on illuminated area, the energy of i row is:

$Q_{(i,0)}=\underset{j=1}{\overset{n}{\mathrm{\Σ}}}{E}_v\·k_{(i,j)}\·S_{(i,j)},$

Simultaneously, above-mentioned equation will meet:

$E_v\·S_v=\underset{i=1}{\overset{m}{\mathrm{\Σ}}}{Q}_{(i,0)},$

Above in two formulas, S _{(i, j)}mean G on illuminated area _{(i, j)}area; According to the light distribution requirements of LED car headlamp, illumination controlling elements k is set _{(i, j)}control the brightness value size of appointed area on illuminated area, the Illumination Distribution met the demands in order to formation, E _vk _{(i, j)}mean G on illuminated area _{(i, j)}brightness value, k _{(i, j)}the value size according to illumination requirement on illuminated area, set, the larger regional k for illumination _{(i, j)}value larger, the less regional k for illumination _{(i, j)}value less;

The energy that on illuminated area, j is capable is:

$Q_{(0,j)}=\underset{i=1}{\overset{m}{\mathrm{\Σ}}}{E}_v\·k_{(i,j)}\·S_{(i,j)},$

Simultaneously, above-mentioned equation will meet:

$E_v\·S_v=\underset{j=1}{\overset{n}{\mathrm{\Σ}}}{Q}_{(0,j)},$

Then corresponding to the grid on illuminated area, divide, by law of conservation of energy, the grid division is carried out in the micro rectangle zone of outgoing collimated light beam, at first this micro rectangle zone is listed as to division, Energy distribution corresponding to i row on illuminated area, according to law of conservation of energy, the energy of these micro rectangle zone i row is:

E _o·b·p _i＝Q _(i,0)，

In formula, p _ifor the width of these micro rectangle zone i row, combine above-mentioned a few formula and can solve p _i;

In like manner, division is gone in this micro rectangle zone, according to law of conservation of energy, j capable energy in this rectangle zonule is:

E _o·a·q _j＝Q _(0,j)，

In formula, q _jfor the capable width of this micro rectangle zone j, combine above-mentioned a few formula and solve q _j; By these two p that equation calculates _iand q _jthe grid that completes this micro rectangle zone is divided, same, and each little lattice is numbered, and i is listed as the g that is numbered of the capable little lattice of j _{(i, j)};

Finally, according to the grid in field of illumination and beam cross section micro rectangle zone, divide, utilize the law of refraction to calculate lenticular free form surface.

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