CN104534407B - A kind of satisfied half light intensity angle is at the optical design method of 8 degree of circular light spots - Google Patents

Abstract

Meet half light intensity angle at an optical design method for 8 degree of circular light spots, comprise the following steps: (1) design reflector and a light-guiding pillar, described light-guiding pillar is placed in the center of described reflector; The reflecting surface of described reflector is the second free form surface, and one end of described light-guiding pillar is that plane forms the plane of incidence, and the other end of light-guiding pillar is in being recessed to form exit facet, and this exit facet is the first free form surface, and the side of light-guiding pillar is reflecting surface; (2) light passes into the reflecting surface being refracted to light-guiding pillar side from the plane of incidence of light-guiding pillar, then through reflexing to the first free form surface of light-guiding pillar, then through being refracted to the second free form surface of reflector, the injection parallel with optical axis of last emergent ray; (3) energy after over-light-transferring pole and reflector and the relation of energy being irradiated to photometric screen is set up according to law of conservation of energy, adjustment the second free form surface of reflector and the first free form surface of light-guiding pillar, obtain light intensity angle at 8 degree of circular light spots at photometric screen.

Description

A kind of satisfied half light intensity angle is at the optical design method of 8 degree of circular light spots

Technical field

The present invention relates to field of LED illumination, especially a kind of satisfied half light intensity angle is at the optical design method of 8 degree of circular light spots.

Background technology

LED illumination is applied on auto lamp by floodlight, and LED car lamp the most frequently used at present comprises the car light of car headlamp, automobile signal light lamp routine.For the lighting of offroad vehicle, its light efficiency requires relatively stricter, and the light of injection meets half light intensity angle at 8 degree of circular light spots.Optical accessories common at present such as reflector, lens etc. all can not meet the demands, therefore need specialized designs to go out this optical requirement that a optical accessories could meet offroad vehicle.

Summary of the invention

Technical problem to be solved by this invention is to provide a kind of satisfied half light intensity angle at the optical design method of 8 degree of circular light spots, can design the optical accessories of satisfied half light intensity angle at 8 degree of circular light spots.

For solving the problems of the technologies described above, technical scheme of the present invention is: a kind of satisfied half light intensity angle, at the optical design method of 8 degree of circular light spots, comprises the following steps:

(1) design a reflector and a light-guiding pillar, described light-guiding pillar is placed in the center of described reflector; The reflecting surface of described reflector is the second free form surface, and one end of described light-guiding pillar is that plane forms the plane of incidence, and the other end of light-guiding pillar is in being recessed to form exit facet, and this exit facet is the first free form surface, and the side of light-guiding pillar is reflecting surface;

(2) light passes into the reflecting surface being refracted to light-guiding pillar side from the plane of incidence of light-guiding pillar, then through reflexing to the first free form surface of light-guiding pillar, then through being refracted to the second free form surface of reflector, the injection parallel with optical axis of last emergent ray;

(3) energy after over-light-transferring pole and reflector and the relation of energy being irradiated to photometric screen is set up according to law of conservation of energy, adjustment the second free form surface of reflector and the first free form surface of light-guiding pillar, obtain light intensity angle at 8 degree of circular light spots at photometric screen.

As improvement, the method for designing of the second free form surface of described reflector:

Light is by collimating outgoing after the second free form surface, so collimated ray is parallel with central shaft, θ is the angle of second free form surface any point place's normal and collimated ray, for the refraction angle that light penetrates from the first free form surface, the equation that the point therefore on free curve meets is:

N (x ⁰, y ⁰) be (x _n, y _n) initial value, this initial value is the value that the first free form surface obtains, and the x at every turn calculated, y value is brought into the next one (x _n, y _n) in, obtain discrete point on the second free form surface by this method.

As improvement, the concrete steps of described step (3) are:

Zoning on photometric screen, sets up energy after over-light-transferring pole and anti-reflector and the relational equation of energy being irradiated to photometric screen according to law of conservation of energy;

If given Light distribation is P ₀, the central light strength of light source is I ₀, consideration direction is θ ₁the position of photometric screen incided of light be r ₁, be less than θ with axis angle ₁the position coordinates of light incidence be also less than r ₁, by Part I light θ ₁be divided into i part, each θ corresponding ₁in radius r ₁on all divide into i part, so just obtain array θ ₁(i) and r ₁(i), the conservation of energy expression formula of the illumination so on first area emergent light and screen is:

$2\mathrm{\π}{\∫}_0^{{\mathrm{\θ}}_1\left(i\right)}{I}_0\cos \mathrm{\θ}\sin \mathrm{\θ}\·\mathrm{d\θ}=2\mathrm{\π}{\∫}_0^{r_1\left(i\right)}{P}_0\·r\·\mathrm{dr}---\left(4\right)$

Angle is θ ₁~ θ ₂between light be r to the position of photometric screen ₁~ r ₂, this part light is divided into j part, and each angle corresponding divide into j part on radius, then the conservation of energy expression formula of the illumination on second area emergent light and screen is:

$2\mathrm{\π}{\∫}_{{\mathrm{\θ}}_1}^{{\mathrm{\θ}}_2\left(j\right)}{I}_0\cos \mathrm{\θ}\sin \mathrm{\θ}\·\mathrm{d\θ}=2\mathrm{\π}{\∫}_{r_1}^{r_2\left(j\right)}{P}_0\·r\·\mathrm{dr}---\left(5\right)$

In like manner, can obtain the 3rd region energy conservation expression formula is:

$2\mathrm{\π}{\∫}_{{\mathrm{\θ}}_2}^{{\mathrm{\θ}}_3\left(k\right)}{I}_0\cos \mathrm{\θ}\sin \mathrm{\θ}\·\mathrm{d\θ}=2\mathrm{\π}{\∫}_{r_2}^{r_3\left(i\right)}{P}_0\·r\·\mathrm{dr}---\left(6\right)$

By these three expression formulas, the relational expression that can obtain respectively between each zone radius and emergent light angle is as follows:

$r_1\left(i\right)=\sqrt{\frac{I_0}{P_0}\·{\sin }^2{\mathrm{\θ}}_1\left(i\right)}---\left(7\right)$

$r_2\left(j\right)=\sqrt{\frac{I_0}{P_0}\·({\sin }^2{\mathrm{\θ}}_2\left(j\right)-{\sin }^2{\mathrm{\θ}}_1)+{r_1}^2}---\left(8\right)$

$r_3\left(k\right)=\sqrt{\frac{I_0}{P_0}\·({\sin }^2{\mathrm{\θ}}_3\left(k\right)-{\sin }^2{\mathrm{\θ}}_2)+{r_2}^2}---\left(9\right)$

The plane of incidence of light-guiding pillar and the first free form surface application law of refraction:

$\frac{\sin \mathrm{\θ}}{\sin {\mathrm{\θ}}^{\′}}=\frac{n^{\′}}{n}---\left(10\right)$

In the plane of incidence of light from air incidence to light-guiding pillar, the refractive index of air is n=1, and light-guiding pillar uses material PC to make, refractive index n=1.591, light refraction to the first free form surface A point coordinates value of light-guiding pillar can try to achieve into (ftan (θ), f), light is through being refracted to the second free form surface B point of reflector, and the slope value of refracted ray AB is cot (θ '), utilize point slope form can obtain the linear equation of AB;

θ indicates incidence angle: θ ' and represents refraction angle;

Light is reflecting when the second free form surface of the reflecting surface of over-light-transferring pole and reflector, and the vector form of catadioptric law can be expressed as:

$\stackrel{\mathrm{uu}}{N}=\stackrel{\mathrm{uuu}}{\mathrm{Out}}-n\×\stackrel{\mathrm{uu}}{\mathrm{In}}$

(11)

Wherein: n is the first free form surface medium refraction index, for incident ray unit vector, for emergent ray unit vector, for free form surface is at the unit normal vector of light point;

When calculating the first free form surface, first an initial point calculated is determined, if light point B coordinate incided on the first free form surface after the plane of incidence refraction of over-light-transferring pole and the reflective surface of light-guiding pillar is (x, z), the point D coordinate that light is projected on screen by the second free form surface collimated reflected of reflector after the first free form surface refraction of over-light-transferring pole is (r, H), wherein H=25m, r are determined by formula (7), (8), (9) according to law of conservation of energy; So, the unit vector of the emergent ray BC in incident ray AB and the first free form surface (emergent ray BC by final emergent ray CD according to formula (11)) all can be tried to achieve, recycling law of refraction formula (11)) normal vector of B point can be obtained, collimation and reflection law is utilized to try to achieve the normal vector of C point, thus determine the section of this point, incide the ray intersection on the first free form surface after this section and the more lower plane of incidence through over-light-transferring pole reflect thus determine the more lower of the first free form surface; Obtain down a bit by the straight line intersection at more front section and more lower normal vector place, the coordinate of each point can be obtained by computer iterations, thus determine the coordinate of each point on the first free form surface.

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

The optical accessories that the present invention designs comprises the reflector with the second free form surface and the light-guiding pillar with the first free form surface, light after light-guiding pillar can 360 degree luminous, in the line of collimation substantially parallel with optical axis injection after light refraction to reflector, meet the optical requirement of half light intensity angle at 8 degree of circular light spots.

Accompanying drawing explanation

Fig. 1 is design flow diagram of the present invention.

Fig. 2 is distribution of light figure.

Fig. 3 is Random Curved Surface Designing figure I.

Fig. 4 is Random Curved Surface Designing figure II.

Fig. 5 is the schematic diagram that light-guiding pillar is combined with reflector.

Fig. 6 is the decomposition view of light-guiding pillar and reflector.

Fig. 7 is the cross section view of light-guiding pillar and reflector.

Detailed description of the invention

Below in conjunction with Figure of description, the invention will be further described.

As shown in Figure 1, a kind of satisfied half light intensity angle, at the optical design method of 8 degree of circular light spots, is characterized in that, comprises the following steps:

(1) as shown in Figs. 5 to 7, design a reflector 1 and a light-guiding pillar 2, described light-guiding pillar 2 is placed in the center of described reflector 1; The reflecting surface of described reflector 1 is the second free form surface 11, and one end of described light-guiding pillar 2 is that plane forms the plane of incidence 21, and the other end of light-guiding pillar 2 is in being recessed to form exit facet, and this exit facet is the first free form surface 23, and the side of light-guiding pillar 2 is reflecting surface 22;

(2) light passes into the reflecting surface 22 being refracted to light-guiding pillar 2 side from the plane of incidence 21 of light-guiding pillar 2, then through reflexing to the first free form surface 23 of light-guiding pillar 2, then through being refracted to the second free form surface 11 of reflector 1, the injection parallel with optical axis of last emergent ray;

(3) energy after over-light-transferring pole 2 and reflector 1 and the relation of energy being irradiated to photometric screen is set up according to law of conservation of energy, adjustment the second free form surface 11 of reflector 1 and the first free form surface 23 of light-guiding pillar 2, obtain light intensity angle at 8 degree of circular light spots at photometric screen.

The method for designing of the second free form surface 11 of described reflector 1:

As shown in Figure 3, light is by collimating outgoing after the second free form surface 11, so collimated ray is parallel with central shaft, θ is the angle of second free form surface 11 any point place's normal and collimated ray, for the refraction angle that light penetrates from the first free form surface 23, the equation that the point therefore on free curve meets is:

N (x ⁰, y ⁰) be (x _n, y _n) initial value, this initial value is the value that the first free form surface 23 obtains, and the x at every turn calculated, y value is brought into the next one (x _n, y _n) in, obtain discrete point on the second free form surface 11 by this method.

Zoning on photometric screen, sets up energy after over-light-transferring pole 2 and anti-reflector 1 and the relational equation of energy being irradiated to photometric screen according to law of conservation of energy.

As shown in Figure 2, if given Light distribation is P ₀, the central light strength of light source is I ₀, consideration direction is θ ₁the position of photometric screen incided of light be r ₁, be less than θ with axis angle ₁the position coordinates of light incidence be also less than r ₁, by Part I light θ ₁be divided into i part, each θ corresponding ₁in radius r ₁on all divide into i part, so just obtain array θ ₁(i) and r ₁(i), the conservation of energy expression formula of the illumination so on first area emergent light and screen is:

$2\mathrm{\π}{\∫}_0^{{\mathrm{\θ}}_1\left(i\right)}{I}_0\cos \mathrm{\θ}\sin \mathrm{\θ}\·\mathrm{d\θ}=2\mathrm{\π}{\∫}_0^{r_1\left(i\right)}{P}_0\·r\·\mathrm{dr}---\left(4\right)$

Angle is θ ₁~ θ ₂between light be r to the position of photometric screen ₁~ r ₂, this part light is divided into j part, and each angle corresponding divide into j part on radius, then the conservation of energy expression formula of the illumination on second area emergent light and screen is:

$2\mathrm{\π}{\∫}_{{\mathrm{\θ}}_1}^{{\mathrm{\θ}}_2\left(j\right)}{I}_0\cos \mathrm{\θ}\sin \mathrm{\θ}\·\mathrm{d\θ}=2\mathrm{\π}{\∫}_{r_1}^{r_2\left(j\right)}{P}_0\·r\·\mathrm{dr}---\left(5\right)$

In like manner, can obtain the 3rd region energy conservation expression formula is:

$2\mathrm{\π}{\∫}_{{\mathrm{\θ}}_2}^{{\mathrm{\θ}}_3\left(k\right)}{I}_0\cos \mathrm{\θ}\sin \mathrm{\θ}\·\mathrm{d\θ}=2\mathrm{\π}{\∫}_{r_2}^{r_3\left(i\right)}{P}_0\·r\·\mathrm{dr}---\left(6\right)$

By these three expression formulas, the relational expression that can obtain respectively between each zone radius and emergent light angle is as follows:

$r_1\left(i\right)=\sqrt{\frac{I_0}{P_0}\·{\sin }^2{\mathrm{\θ}}_1\left(i\right)}---\left(7\right)$

$r_2\left(j\right)=\sqrt{\frac{I_0}{P_0}\·({\sin }^2{\mathrm{\θ}}_2\left(j\right)-{\sin }^2{\mathrm{\θ}}_1)+{r_1}^2}---\left(8\right)$

$r_3\left(k\right)=\sqrt{\frac{I_0}{P_0}\·({\sin }^2{\mathrm{\θ}}_3\left(k\right)-{\sin }^2{\mathrm{\θ}}_2)+{r_2}^2}---\left(9\right)$

The plane of incidence and first free form surface 23 of light-guiding pillar 2 apply the law of refraction:

$\frac{\sin \mathrm{\θ}}{\sin {\mathrm{\θ}}^{\′}}=\frac{n^{\′}}{n}---\left(10\right)$

As shown in Figure 3,4, light from air incidence to light-guiding pillar 2 the plane of incidence in, the refractive index of air is n=1, and light-guiding pillar 2 uses material PC to make, refractive index n=1.591, light refraction can be tried to achieve as (ftan (θ) to the first free form surface 23A point coordinates value of light-guiding pillar 2, f), light is through being refracted to the B point of the second free form surface 11 of reflector 1, and the slope value of refracted ray AB is cot (θ '), utilizes point slope form can obtain the linear equation of AB;

θ indicates incidence angle: θ ' and represents refraction angle;

Light is reflecting when the second free form surface 11 of the reflecting surface of over-light-transferring pole 2 and reflector 1, and the vector form of catadioptric law can be expressed as:

$\stackrel{\mathrm{uu}}{N}=\stackrel{\mathrm{uuu}}{\mathrm{Out}}-n\×\stackrel{\mathrm{uu}}{\mathrm{In}}$

(11)

Wherein: n is the first free form surface 23 medium refraction index, for incident ray unit vector, for emergent ray unit vector, for free form surface is at the unit normal vector of light point;

When calculating the first free form surface 23, first an initial point calculated is determined, if light point B coordinate incided on the first free form surface 23 after the plane of incidence refraction of over-light-transferring pole 2 and the reflective surface of light-guiding pillar 2 is (x, z), the point D coordinate that light is projected on screen by the second free form surface 11 collimated reflected of reflector 1 after the first free form surface 23 of over-light-transferring pole 2 reflects is (r, H), wherein H=25m, r are determined by formula (7), (8), (9) according to law of conservation of energy; So, the unit vector of the emergent ray BC in incident ray AB and the first free form surface 23 (emergent ray BC by final emergent ray CD according to formula (11)) all can be tried to achieve, recycling law of refraction formula (11)) normal vector of B point can be obtained, collimation and reflection law is utilized to try to achieve the normal vector of C point, thus determine the section of this point, incide the ray intersection on the first free form surface 23 after this section and the more lower plane of incidence through over-light-transferring pole 2 reflect thus determine the more lower of the first free form surface 23; Obtain down a bit by the straight line intersection at more front section and more lower normal vector place, the coordinate of each point can be obtained by computer iterations, thus determine the coordinate of each point on the first free form surface 23.

Claims (2)

1. meet half light intensity angle at an optical design method for 8 degree of circular light spots, it is characterized in that,

Comprise the following steps:

(1) design a reflector and a light-guiding pillar, described light-guiding pillar is placed in the center of described reflector; The reflecting surface of described reflector is the second free form surface, and one end of described light-guiding pillar is that plane forms the plane of incidence, and the other end of light-guiding pillar is in being recessed to form exit facet, and this exit facet is the first free form surface, and the side of light-guiding pillar is reflecting surface;

(2) light passes into the reflecting surface being refracted to light-guiding pillar side from the plane of incidence of light-guiding pillar, then through reflexing to the first free form surface of light-guiding pillar, then through being refracted to the second free form surface of reflector, the injection parallel with optical axis of last emergent ray;

(3) energy after over-light-transferring pole and reflector and the relation of energy being irradiated to photometric screen is set up according to law of conservation of energy, adjustment the second free form surface of reflector and the first free form surface of light-guiding pillar, obtain half light intensity angle at 8 degree of circular light spots at photometric screen;

The concrete steps of described step (3) are:

Zoning on photometric screen, sets up energy after over-light-transferring pole and reflector and the relational equation of energy being irradiated to photometric screen according to law of conservation of energy;

If given Light distribation is P ₀, the central light strength of light source is I ₀, consideration direction is θ ₁the position of photometric screen incided of light be r ₁, be less than θ with axis angle ₁the position coordinates of light incidence be also less than r ₁, by Part I light θ ₁be divided into i part, each θ corresponding ₁in radius r ₁on all divide into i part, so just obtain array θ ₁(i) and r ₁(i), the conservation of energy expression formula of the illumination so on first area emergent light and screen is:

Angle is θ ₁~ θ ₂between light be r to the position of photometric screen ₁~ r ₂, this part light is divided into j part, and each angle corresponding divide into j part on radius, then the conservation of energy expression formula of the illumination on second area emergent light and screen is:

In like manner, can obtain the 3rd region energy conservation expression formula is:

By these three expression formulas, the relational expression that can obtain respectively between each zone radius and emergent light angle is as follows:

The plane of incidence of light-guiding pillar and the first free form surface application law of refraction:

In the plane of incidence of light from air incidence to light-guiding pillar, the refractive index of air is n=1, and light-guiding pillar uses material PC to make, refractive index n=1.591, light refraction to the first free form surface A point coordinates value of light-guiding pillar can try to achieve into (ftan (θ), f), light is through being refracted to the second free form surface B point of reflector, and the slope value of refracted ray AB is cot (θ '), utilize point slope form can obtain the linear equation of AB;

θ indicates incidence angle: θ ' and represents refraction angle;

Light is reflecting when the second free form surface of the reflecting surface of over-light-transferring pole and reflector, and the vector form of catadioptric law can be expressed as:

Wherein: n is the first free form surface medium refraction index, for incident ray unit vector, for emergent ray unit vector, for free form surface is at the unit normal vector of light point;

When calculating the first free form surface, first an initial point calculated is determined, if light point B coordinate incided on the first free form surface after the plane of incidence refraction of over-light-transferring pole and the reflective surface of light-guiding pillar is (x, z), the point D coordinate that light is projected on screen by the second free form surface collimated reflected of reflector after the first free form surface refraction of over-light-transferring pole is (r, H), wherein H=25m, r are determined by formula (7), (8), (9) according to law of conservation of energy; So, the unit vector of the emergent ray BC in incident ray AB and the first free form surface all can be tried to achieve, wherein emergent ray BC is tried to achieve according to formula (11) by final emergent ray CD, recycling law of refraction formula (11) can obtain the normal vector of B point, collimation and reflection law is utilized to try to achieve the normal vector of C point, thus determine the section of this point, incide the ray intersection on the first free form surface after this section and the more lower plane of incidence through over-light-transferring pole reflect thus determine the more lower of the first free form surface; Obtain down a bit by the straight line intersection at more front section and more lower normal vector place, the coordinate of each point can be obtained by computer iterations, thus determine the coordinate of each point on the first free form surface.

2. a kind of satisfied half light intensity angle according to claim 1 is at the optical design method of 8 degree of circular light spots, it is characterized in that: the method for designing of the second free form surface of described reflector: light is by collimating outgoing after the second free form surface, so collimated ray is parallel with central shaft, θ is the angle of second free form surface any point place's normal and collimated ray for the refraction angle that light penetrates from the first free form surface, the equation that the point therefore on the second free form surface meets is:

N (x ₀, y ₀) be (x _n, y _n) initial value, this initial value is the value that the first free form surface obtains, and the x at every turn calculated, y value is brought into the next one (x _n, y _n) in, obtain discrete point on the second free form surface by this method.