CN201811146U - Free-form surface spreadlight lens for illumination of high-power LED streetlight - Google Patents

Abstract

The utility model discloses a free-form surface spreadlight lens for illumination of a high-power LED streetlight, comprising an LED light incident plane, an emitting plane and a bottom surface, wherein a pit is arranged in the middle of the bottom surface of the lens and internally provided with an LED, and the wall surface of the pit is hemispherical so as to form the incident plane; and except for the bottom surface, the external surface of the lens is a free-form surface so as to form the emitting plane. An axis which adopts the centre of a circle at the bottom of an LED lamp as an original point and the plane where the LED bottom surface is positioned as an XOY plane, passes through the original point and is perpendicular to the XOY plane is a Z axis, the shape of the spreadlight lens is symmetrical relative to the YOZ plane, and the shape of free-form surface of the lens is obtained by symmetrizing the free-form surface of the spreadlight lens in the first quartile and the fourth quartile relative to the YOZ plane. The free-form surface spreadlight lens for the illumination of the high-power LED streetlight restricts the light-emitting direction of the LED through the free-form surface at the external surface of the spreadlight lens, so that an illuminated area can form a rectangular uniform illumination surface, and the free-form surface spreadlight lens meets the national requirement of roadway illumination on light distribution and intensity of illumination.

Description

The free form surface spreadlight lens that is used for the high-power LED street lamp illumination

Technical field

The utility model belongs to the LED lighting technical field, is specifically related to a kind of spreadlight lens of LED street lamp.

Background technology

LED is as a kind of novel solid light source, compares with traditional light source to have a lot of advantages, and as energy-conservation, therefore advantage such as environmental protection is easy to regulate, and the life-span is long is suitable as the light source of various lighting fields, such as the road lighting light source very much.

Roadway lighting system is different from general lighting, and the field of its illumination is preferably the rectangular area, to improve the utilization rate of light.According to the national highway lighting criteria, satisfy the average illumination and the uniformity of illuminance of on the plane of illumination of a rectangle (generally being 10 meters * 40 meters).

Because the approximate lambert's type of the light that led light source sends, promptly light intensity is cosine distribution, is directly used in illumination, can form a uneven round spot on the road surface, and the center is very bright, and very fast in radial decay.This just needs the design corresponding optical system to come luminous intensity distribution again.The present LED street lamp that occurs, there is the spreadlight lens of use that led light source is carried out luminous intensity distribution, the efficiency of light energy utilization of this street lamp is very high, but can't break up because central light strength is excessive, cause single street lamp irradiation distance to lack (generally at 30 meters to 35 meters), if the street lamp installing space is bigger, can between two lamps the dark space appear.And the light-configuration mode of existing comparative maturity is to lay optical lens before led light source, wherein reasonablely is peanut type lens what irradiation distance and uniformity of illuminance were done.But because peanut shape lens adopt symmetric design, and street lamp post generally is to be placed on the roadside, so street lamp in use has a large amount of illumination and is mapped to zone in addition, road surface, is unfavorable for effective utilization of luminous energy.

The utility model content

The purpose of this utility model is to overcome the prior art above shortcomings, and the spreadlight lens of LED street lamp is provided, and the luminous energy of LED street lamp is focused on the road surface, and forms even rectangular illumination zone.The utility model adopts following technical scheme:

Be used for the free form surface spreadlight lens of high-power LED street lamp illumination, comprise LED light entrance face, exit facet and bottom surface, the middle part, bottom surface of described lens is provided with one and supplies LED to be installed on its interior pit, and the hole wall of pit is a hemisphere face, constitutes the described plane of incidence; The outer surface of lens except that bottom surface portions is free form surface, constitutes described exit facet.

Above-mentioned free form surface spreadlight lens, the center of circle with LED lamp bottom surface is an initial point, with plane, place, LED bottom surface is XOY plane, cross initial point and vertical with XOY plane axle is the Z axle, the shape of described spreadlight lens is carried out shape that symmetry promptly obtain the free form surface of lens at first quartile and four-quadrant free form surface part with respect to the YOZ plane by spreadlight lens about the YOZ plane symmetry.

Described free form surface is determined by following method:

(1) determines primary condition and target illumination zone divided grid.

At first the distance of target illumination face and LED is h, the target illumination zone is the long a that is, wide is the rectangular area of b, gets its first quartile and four-quadrant as research object, and then long limit is a/2, because the vertical polarisation in road surface, side is c in the length of first quartile, and four-quadrant length is d, and the total light flux of led light source is φ, the average illumination of target area is Ev (Ev is that total light flux is divided by the target area area), and the LED central light strength is I ₀=φ/π.The target illumination rectangular area is divided into n part along X-direction with step-length k, is divided into m part with step-length k, obtain the array of x (n) and y (m) along Y direction.Just formed the square net of m * n homalographic like this at target illumination zone first quartile.Corresponding, by calculating the energy of each part grid,,, on the θ angle, be divided into n part corresponding to of the division of target illumination zone at first quartile with light source emergent ray discretization,

Be divided into m part on the angle.

(2) the θ angle (the θ angle is the angle on light and plane, Y-axis place and YOZ plane) by the outgoing of conservation of energy compute ray

The first step, calculate the pairing gross energy in every rectangular area of X-direction, target area:

Energy＝k·(c+d)·Ev

In second step, obtain the θ angle by the conservation of energy: (

The angle is the angle of emergent ray and Y-axis forward)

LED outgoing energy is:

The above-mentioned first step and the energy conservation relation in second step are arranged, can draw the iterative relation formula of θ, calculate by computer and can obtain a series of θ values.

(3) calculate by the energy corresponding relation The angle

As research object, area is k with each lattice of target area ²

The first step, calculate the gross energy of each little lattice:

energy＝Ev·k ²

Second step, be corresponding to the outgoing energy of light source:

The 3rd step, above two steps are set up equation, set up double cycle calculations by computer and can obtain

Sequence.

(4) by the law of refraction and obtain the normal vector of putting on the described curved surface, utilize this normal vector to try to achieve the section, obtain the coordinate of putting on the curve by the intersection point of asking section and incident ray.Described reflection law formula is:

${[1+n^2-2n(o\stackrel{\→}{u}t\·i\stackrel{\→}{n})]}^{1/2}\stackrel{\→}{N}=o\stackrel{\→}{u}t-\mathrm{ni}\stackrel{\→}{n}$

Wherein n is a refractive index,

Be the incident ray unit vector,

Be the emergent ray unit vector, For free form surface at certain unit normal vector on a bit;

In calculating, at first determine the initial point of a calculating, this initial point coordinate has determined the size of whole spreadlight lens, calculates a boundary curve by this initial point, is that initial point is calculated whole free form surface by each point on the boundary curve again.Computational methods: by (2), in (3) determined θ and Can obtain the unit vector of incident ray, the unit vector of coordinate by initial point and the reflection ray corresponding with it, can obtain the normal vector of initial point, thereby determine the section of this point, thereby definite second point is intersected with second incident ray in this section.Can draw down a bit with the straight line at the normal vector place of descending any is crossing by more preceding section, can draw the coordinate of being had a few by computer iterations.Determined the coordinate of free form surface thus.

(5) point that utilizes machine emulated software to obtain fits to curved surface

The curved surface that obtains can obtain final spreadlight lens curved surface for corresponding to YOZ level crossing picture.

Above-mentioned free form surface spreadlight lens, m, the value of n is big more, and the discrete point that obtains on the described curved surface is many more, can obtain more accurate described curved surface by these discrete point coordinates by computer fitting.

Above-mentioned free form surface spreadlight lens, described bottom surface are the plane, and the luminous component of LED lamp is positioned at described pit, and the bottom surface of LED lamp and the bottom surface of lens are in the same plane.

Above-mentioned free form surface spreadlight lens, the span of described h are 5～12m, and the span of a is 30～40m, and the span of b is 8～12m.Above-mentioned free form surface spreadlight lens, spreadlight lens is made by bright PC or PMMA.

Compared with prior art, the utlity model has following beneficial effect: the utility model provides a kind of LED road lamp used spreadlight lens, the outer surface free form surface of scioptics retrains the light direction of LED, make its field of illumination become a rectangular uniform illuminated area, the light that meets national road lighting distributes and illumination requirement.Because the LED street lamp lens that uses at present all is symmetric design, a large amount of in use optical energy irradiations arrives the zone beyond the road surface, has lost luminous energy.Consider the shape on street lamp position and road surface, LED lens described in the utility model are adopted as the polarisation rectangular design, then significantly improve the utilization rate of luminous energy.

Description of drawings

Fig. 1 finds the solution led light source and spherical coordinates figure thereof in the lens free form surface in the embodiment.

Fig. 2 is target area first quartile and a four-quadrant division grid chart in the embodiment.

Fig. 3 is the vertical view of lens in the embodiment.

Fig. 4 is the side view of lens in the embodiment.

Fig. 5 is the upward view of lens in the embodiment.

Fig. 6 is the 3 dimensional drawing of lens in the embodiment.

The specific embodiment

Below in conjunction with accompanying drawing enforcement of the present utility model is further described, but enforcement of the present utility model is not limited thereto.

(1) determines primary condition and target illumination zone divided grid, as shown in Figure 1 and Figure 2.

At first the distance of target illumination face and LED is 10m, the target illumination zone is the long 40m that is, wide is the rectangular area of 12m, gets its first quartile and four-quadrant as determining object, determines that then long limit is 20m, because LED light is along the Y-axis polarisation, side is at the length 9m of first quartile, and four-quadrant length is 3m, and the total light flux of led light source 101 is 100lm, then the average illumination of target area is 0.2083lx, and the LED central light strength is 31.8310cd.Target illumination rectangular area 102 is divided into 100 parts along X-direction with step-length 0.2m, is divided into 60 parts with step-length 0.2m, obtain the array of x (101) and y (61): x (1)=0, x (2)=0.2, x (3)=0.4 along Y direction ... and the like; Y (1)=0, y (2)=0.2, y (3)=0.4 ... and the like.Just formed the square net of 100 * 60 homalographics like this at target illumination zone first, fourth quadrant.Corresponding, by calculating the energy of each part grid,,, on the θ angle, be divided into 100 parts corresponding to of the division of target illumination zone at first quartile with light source emergent ray discretization,

Be divided into 60 parts on the angle.

(2) the θ angle by the outgoing of conservation of energy compute ray (the θ angle is a light 107 and the angle on plane, Y-axis place and YOZ plane)

The first step, calculate the pairing last energy in every rectangular area of X-direction, target area:

[0048]?Energy＝k·(c+d)·Ev

[0049]Bring the Energy=0.2 * 12 * 0.2083=0.4999 of data into

In second step, obtain the θ angle by the conservation of energy: (

The angle is the angle of emergent ray 107 and Y-axis forward)

LED outgoing energy is:

Bringing data into gets $\frac{\mathrm{\π}{I}_0}{2}\×(\sin \left(\mathrm{\θ}(n+1)\right)-\sin \left(\mathrm{\θ}\left(n\right)\right))$

The above-mentioned first step and the energy conservation relation in second step are arranged, can draw the iterative relation formula of θ:

$\mathrm{\&theta;}(n+1)=a\sin (\frac{2\&times;\mathrm{Energy}}{\mathrm{\&pi;}\&CenterDot;{\mathrm{<figure-callout\; id="0"\; label="I"\; filenames="DEST\_PATH\_HSB00000392459400011.png,DEST\_PATH\_HSB00000392459400012.png"\; state="\{\{state\}\}">I</figure-callout>}}_0}+\sin \left(\mathrm{\&theta;}\left(n\right)\right)),$ Can obtain a series of θ values by computer calculating.

(3) calculate by the energy corresponding relation

The angle

As research object, area is 0.04m with each lattice of target area ²

The first step, calculate the gross energy of each little lattice:

energy＝Ev·k ²

Bring data into and get energy=0.2083 * 0.04=0.0083

Second step, be corresponding to the outgoing energy of light source:

The 3rd step, above two steps are set up equation, set up double cycle calculations by computer and can obtain Sequence.

(4) by the law of refraction and obtain the normal vector of putting on the described curved surface, utilize this normal vector to try to achieve the section, obtain the coordinate of putting on the curve by the intersection point of asking section and incident ray.Described reflection law formula is:

Wherein n is a refractive index,

Be the incident ray unit vector,

Be the emergent ray unit vector, Be unit normal vector;

In calculating, at first determine the initial point of a calculating, (0,-0.02,0), this initial point coordinate has determined the size of whole spreadlight lens, calculating a boundary curve by this initial point, is that initial point is calculated whole free form surface by each point on the boundary curve again.Computational methods: by (2), in (3) determined θ and Can obtain the unit vector of incident ray, the unit vector of coordinate by initial point and the reflection ray corresponding with it, can obtain the normal vector of initial point, thereby determine the section of this point, thereby definite second point is intersected with second incident ray in this section.Can draw down a bit with the straight line at the normal vector place of descending any is crossing by more preceding section, can draw the coordinate of being had a few by computer iterations.Determined the coordinate of free form surface thus.

(5) point that utilizes machine emulated software to obtain fits to curved surface

The curved surface that obtains can obtain final lens curved surface for corresponding to YOZ level crossing picture.

As Fig. 3, be the lens vertical view that obtains by such scheme, Fig. 4 is lateral body figure, and Fig. 5 is a upward view, and Fig. 6 is a stereogram, and spreadlight lens comprises inner surface 201, outer surface 202 and bottom surface 203.Led light source 101 is placed the central authorities with bottom surface 203.

After adopting technique scheme, make hot spot rectangular and can rationally control distribution of light, and in irradiation area the total light transmittance height, light-emitting uniformity is good.

Claims (4)

1. the free form surface spreadlight lens that is used for the high-power LED street lamp illumination, comprise LED light entrance face, exit facet and bottom surface, the bottom surface middle part that it is characterized in that described lens is provided with one and is installed on pit in it for LED, and the hole wall of pit is a hemisphere face, constitutes the described plane of incidence; The outer surface of lens except that bottom surface portions is free form surface, constitutes described exit facet.

2. free form surface spreadlight lens according to claim 1, it is characterized in that the center of circle with LED lamp bottom surface is an initial point, with plane, place, LED bottom surface is XOY plane, cross initial point and vertical with XOY plane axle is the Z axle, the shape of described spreadlight lens is carried out shape that symmetry promptly obtain the free form surface of lens at first quartile and four-quadrant free form surface part with respect to the YOZ plane by spreadlight lens about the YOZ plane symmetry.

3. free form surface spreadlight lens according to claim 1 is characterized in that described bottom surface is the plane; The luminous component of LED lamp is positioned at described pit, and the bottom surface of LED lamp and the bottom surface of lens are in the same plane.

4. according to each described free form surface spreadlight lens of claim 1～3, it is characterized in that spreadlight lens made by bright material PC or PMMA.

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