CN103343941A - Equal-luminance lighting LED street lamp lens and method for designing same - Google Patents

Abstract

The invention provides an equal-luminance lighting LED street lamp lens and a method for designing the equal-luminance lighting LED street lamp lens. The equal-luminance lighting LED street lamp lens comprises an outer curved face (1), a bottom face (2) and an LED lamp cavity (3) which is arranged on the bottom face. The outer curved face (1) is formed by irregular curved faces which are symmetrical right and left along the central axis. The LED lamp cavity (3) is an inward-concave hemisphere face, and the semi-diameter of the hemisphere face is determined by the size of an LED lamp bead which is selected and used. The outer curved face (1) is a free-form curved face which is worked out by numerical calculating software, objective light intensity of each point of an objective luminous face which is integrated in the program for calculating the free-form curved face is calculated, and therefore the effect that light rays can be refracted by the lens and then precisely illuminate an objective luminous point after being given out is ensured.

Description

A kind of brightness illumination LED street lamp lens and method for designing thereof of waiting

Technical field

The invention belongs to technical field of semiconductor illumination, be specifically related to a kind of brightness illumination LED street lamp lens and method for designing thereof of waiting.

Background technology

After LED enters lighting field, rely on many advantages such as low energy consumption, high light efficiency, fast-response, long-life to become the favourite son of illuminating industry rapidly, this develop rapidly for over ten years, LED commander lighting field has become irresistible gesture.But the light that LED sends is lambertian distribution, is difficult to be directly used in illumination, need carry out the secondary optics design, and being used for different light scenes has different requirements, and therefore brand-new subject---design of LED secondary optics---arises at the historic moment.Encapsulation to led chip is considered as primary optical design, goes out refractor and reflection shield etc. according to the consequence devised of primary optical design and is considered as the secondary optics design with the optical design process that satisfies illumination and use.The main task of secondary optics design is that lambert's type luminous intensity distribution is transformed into the luminous intensity distribution that can be applied to different scene lightings.This process has crucial effects to LED in the application of lighting field.

At present, mostly the design of LED secondary optical lens is to carry out according to Illumination Distribution, and can not very accurately obtain object illumination sometimes.Brightness, can better more directly express target call as the amount that human eye directly obtains, provided in " city illumination design standard CJJ45-2006 " pitch and concrete road surface the simplification luminance factor and with the relation of light intensity, determine that accordingly we can accurately calculate the required light intensity of target illumination point after the lamp position, thus the reverse profile of extrapolating lens.

Summary of the invention

The objective of the invention is to overcome the defective of above-mentioned prior art, proposed a kind of brightness illumination LED street lamp lens and method for designing thereof of waiting.

The present invention is achieved in that a kind of brightness illumination LED street lamp lens that waits, and comprises positive camber (1), bottom surface (2) and LED lamp chamber (3) on the bottom surface is set;

Positive camber (1) is by constituting along the symmetrical irregular curved surface of axis;

LED lamp chamber (3) is the hemisphere face of an indent, and this hemispherical radius is determined by the size of selected LED lamp pearl.

Deng the method for designing of brightness illumination LED street lamp lens, step is as follows:

(1) reads the required light intensity of target illumination face each point from simplifying the luminance factor table;

(2) carry out the energy mapping according to the light distribution of target illumination face in conjunction with the light source intensity distribution;

(3) use numerical computations software to calculate the coordinate of each point on the curved surface;

(4) according to the geometric optics refraction principle, the gained coordinate is imported CAD software carry out modeling, obtain lens model.

The required light intensity of target illumination face each point reads or adopts interpolation method to calculate from simplify the luminance factor table.

The energy mapping is according to law of conservation of energy, luminous flux in a certain solid angle Ω of light source is shone upon by the luminous flux in light distribution and a certain solid angle Ω ' after the lens refraction, and namely the luminous flux in the luminous flux in a certain solid angle Ω of light source and a certain solid angle Ω ' after the lens refraction is identical.

Effective effect that the present invention obtains is: carry out the LED secondary optical lens according to light distribution, this method is from the relation of luminous flux and light intensity, law of conservation of energy is deferred in strictness, luminous flux in a certain solid angle of lamp pearl outgoing is corresponding with another solid angle after the lens refraction, LED lamp pearl is close to all light refractions in illuminated area, has taken full advantage of the light source light energy.Through illumination design software DiaLux checking, prove that lens can satisfy road illumination standards, luminance uniformity exceeds more than 20 percentage point than standard, approaches to wait brightness.

Description of drawings

Fig. 1 is the isometric front view that the present invention waits brightness illumination LED street lamp lens.

Fig. 2 is the reverse side stereogram that the present invention waits brightness illumination LED street lamp lens.

Fig. 3 is the geometrical relationship schematic diagram of target illumination point and light fixture.

Fig. 4 is the light refraction schematic diagram.

The specific embodiment

Referring to Fig. 1 and Fig. 2, a kind of brightness illumination LED street lamp lens that waits comprises positive camber 1, bottom surface 2 and LED lamp chamber 3 on the bottom surface is set;

Positive camber 1 is by constituting along the symmetrical irregular curved surface of axis;

LED lamp chamber 3 is hemisphere faces of an indent, and this hemispherical radius is determined by the size of selected LED lamp pearl.

Deng the method for designing of brightness illumination LED street lamp lens, step is as follows:

(1) the target light intensity of calculating target illumination face each point

A) according to simplifying the luminance factor table can be read some specified point on the illuminated area in conjunction with geometrical relationship simplification luminance factor in " city illumination design standard CJJ45-2006 ".

Point of observation is arranged on the place apart from lamp stand 60m, and is positioned in the middle of the track, can obtain tan (γ) and the β of position correspondence on the target face according to the geometrical relationship of Fig. 3, corresponding relation is as follows:

$\tan (\mathrm{\γ})=\frac{\sqrt{x^2+{(y-t)}^2}}{h}---\left(1\right)$

$\mathrm{\&beta;}=\left\{\begin{array}{cc}|90-\arctan \left(\frac{t-y}{x}\right)\&times;\frac{180}{\mathrm{\&pi;}}-\arctan \left(\frac{c+x}{a/2-y}\right)\&times;\frac{180}{\mathrm{\&pi;}}|& 0\&le;y\&le;t\\ 180-\arctan \left(\frac{x}{y-t}\right)\&times;\frac{180}{\mathrm{\&pi;}}-\arctan \left(\frac{c+x}{a/2-y}\right)\&times;\frac{180}{\mathrm{\&pi;}}& t<y\&le;a/2\\ \arctan \left(\frac{c+x}{y-a/2}\right)\&times;\frac{180}{\mathrm{\&pi;}}-\arctan \left(\frac{x}{y-t}\right)\&times;\frac{180}{\mathrm{\&pi;}}& a/2\&le;y\&le;a\end{array}\right.---\left(2\right)$

Wherein a is the road half-breadth, and b is half length of lamp lighting scope, and c is the distance of point of observation and lamp stand, and h is pole height, t be light fixture with respect to the outstanding length of road edge, x, y are respectively the coordinate of putting on the road surface.Can be calculated tan (γ) and the β of the some correspondence on the road surface by formula (1) (2).

B) notice that tan in the coefficient table (γ) is very limited with the value of β, draw the coefficient of some specified point only, we adopt interpolation method to read for the coefficient that can not directly read in the table.Describe with an example below, establish certain and put corresponding tan (γ) and β, and satisfy tan (γ) ₁≤ tan (γ)＜tan (γ) ₂, β ₁≤ β＜β ₂, it is as shown in the table,

	β 1	β 2
			tan(γ) 1	r 1	r 2
tan(γ) 2	r 3	r 4

Then can try to achieve the corresponding coefficient V of this point with interpolation method is:

$r=\{{\mathrm{<figure-callout\; id="1"\; label="r"\; filenames="130725144321.png"\; state="\{\{state\}\}">r</figure-callout>}}_1+\frac{r_3-{\mathrm{<figure-callout\; id="1"\; label="r"\; filenames="130725144321.png"\; state="\{\{state\}\}">r</figure-callout>}}_1}{\tan {\left(\mathrm{\&gamma;}\right)}_2-\tan {\left(\mathrm{\&gamma;}\right)}_1}[\tan \left(\mathrm{\&gamma;}\right)-\tan {\left(\mathrm{\&gamma;}\right)}_1\left]\right\}+(\mathrm{\&beta;}-{\mathrm{\&beta;}}_1)$

$\&times;\&lang;\frac{\{{\mathrm{<figure-callout\; id="2"\; label="r"\; filenames="130725144326.png"\; state="\{\{state\}\}">r</figure-callout>}}_2+\frac{r_4-{\mathrm{<figure-callout\; id="2"\; label="r"\; filenames="130725144326.png"\; state="\{\{state\}\}">r</figure-callout>}}_2}{\tan {\left(\mathrm{\&gamma;}\right)}_2-\tan {\left(\mathrm{\&gamma;}\right)}_1}[\tan \left(\mathrm{\&gamma;}\right)-\tan {\left(\mathrm{\&gamma;}\right)}_1\left]\right\}-\{{\mathrm{<figure-callout\; id="1"\; label="r"\; filenames="130725144321.png"\; state="\{\{state\}\}">r</figure-callout>}}_1+\frac{r_3-{\mathrm{<figure-callout\; id="1"\; label="r"\; filenames="130725144321.png"\; state="\{\{state\}\}">r</figure-callout>}}_1}{\tan {\left(\mathrm{\&gamma;}\right)}_2-\tan {\left(\mathrm{\&gamma;}\right)}_1}[\tan \left(\mathrm{\&gamma;}\right)-\tan {\left(\mathrm{\&gamma;}\right)}_1\left]\right\}}{{\mathrm{\&beta;}}_2-{\mathrm{\&beta;}}_1}\&rang;---\left(3\right)$

C) obtain behind the coefficient coefficient being converted to light intensity by (4) formula,

$I=\frac{1000}{r}---\left(4\right)$

Obtain the needed target light intensity of each lighting point.

(2) carry out the energy mapping according to the light distribution of target illumination face in conjunction with the light source intensity distribution

The light distribution of led light source Wei Lang uncle type

I(θ)=I ₀*cos(θ) （5）

Can be extrapolated by conservation of energy principle:

$\mathrm{\&Delta;\&gamma;}=\frac{I\left(\mathrm{\&theta;}\right)*\sin \left(\mathrm{\&theta;}\right)*\mathrm{\&Delta;\&theta;}}{I\left(\mathrm{\&gamma;}\right)*\sin \left(\mathrm{\&gamma;}\right)}---\left(6\right)$

The following formula discretization is got:

${\mathrm{\&gamma;}}_{i+1}={\mathrm{\&gamma;}}_i+\frac{I\left({\mathrm{\&theta;}}_i\right)*\sin \left({\mathrm{\&theta;}}_i\right)*\mathrm{\&Delta;}{\mathrm{\&theta;}}_i}{I\left({\mathrm{\&gamma;}}_i\right)*\sin \left({\mathrm{\&gamma;}}_i\right)}---\left(7\right)$

Thereby the target illumination point that can draw each light by geometrical relationship is:

Tx _i≈z*tan(γ _i) （8）

(3) use numerical computations software to calculate the coordinate of each point on the curved surface

As shown in Figure 4, as long as the θ angle is divided, it is the position that the light of θ requires the impact point that will shine with z axle clamp angle that combining target illuminated area each point light intensity just can draw every, namely determines starting point and the last point of light.

(4) according to the geometric optics refraction principle, the gained coordinate is imported CAD software carry out modeling, obtain lens model.

According to the geometric optics refraction principle, in conjunction with each light and respective objects illuminated area each point position, set the elemental height of lens centre, use iterative algorithm can calculate the coordinate of curved surface each point, at last each coordinate points is imported the positive camber that CAD software can obtain lens, be an entity with the curved surface completion, and the transverse plane of will going to the bottom excavates hemisphere face, just obtain the profile of whole lens.

What more than enumerate only is a specific embodiment of the present invention.Obviously, the invention is not restricted to above embodiment, many shapes that similarly change can also be arranged.All distortion that those of ordinary skill in the art can directly derive or associate from content disclosed by the invention all should be thought invention which is intended to be protected.

Claims (4)

1. one kind is waited brightness illumination LED street lamp lens, comprises positive camber (1), bottom surface (2) and LED lamp chamber (3) on the bottom surface is set;

Positive camber (1) is by constituting along the symmetrical irregular curved surface of axis;

LED lamp chamber (3) is the hemisphere face of an indent, and this hemispherical radius is determined by the size of selected LED lamp pearl.

2. the described method for designing that waits brightness illumination LED street lamp lens of claim 1, step is as follows:

(1) reads the required light intensity of target illumination face each point from simplifying the luminance factor table;

(2) carry out the energy mapping according to the light distribution of target illumination face in conjunction with the light source intensity distribution;

(3) use numerical computations software to calculate the coordinate of each point on the curved surface;

(4) according to the geometric optics refraction principle, the gained coordinate is imported CAD software carry out modeling, obtain lens model.

3. the method for designing that waits brightness illumination LED street lamp lens as claimed in claim 2, it is characterized in that: the required light intensity of target illumination face each point reads or adopts interpolation method to calculate from simplify the luminance factor table.

4. the method for designing that waits brightness illumination LED street lamp lens as claimed in claim 2, it is characterized in that: the energy mapping is according to law of conservation of energy, luminous flux in a certain solid angle Ω of light source is shone upon by the luminous flux in light distribution and a certain solid angle Ω ＇ after the lens refraction, and namely the luminous flux in the luminous flux in a certain solid angle Ω of light source and a certain solid angle Ω ＇ after the lens refraction is identical.

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