CN102486290A - Light-emitting diode (LED) indoor illumination optical lens - Google Patents

Abstract

The invention discloses a light-emitting diode (LED) indoor illumination optical lens, which is of a rotary symmetrical structure, wherein a concave hemispherical surface which makes the LED emergent ray enter the lens without deflection is arranged at the bottom of the optical lens, an LED is installed at the sphere center of the hemispherical surface, the external surface of the optical lens is a free-form surface which controls the direction of the LED emergent ray and has continuously changed curvature, the radius of the hemispherical surface is 1/3R to 1/2R, wherein R is the radius of the bottom of the optical lens. The LED indoor illumination optical lens has a simple structure, reasonable design, uniform LED illumination, high illumination efficiency, widened LED utilization scope, is energy-saving and environmental-friendly, has a good use effect, and is convenient to popularize and use.

Description

LED room lighting optical lens

Technical field

The invention belongs to LED room lighting technical field, especially relate to a kind of LED room lighting optical lens.

Background technology

Along with the continuous development of semi-conducting material and technology, light emitting diode (LED) replaces conventional light source just gradually, becomes light source of new generation.Though it has advantages such as high-efficiency environment friendly, durable safety, its output intensity is cosine distribution roughly, therefore is considered to the Lambertian radiator that is similar to usually.Such optical field distribution, if handle and directly application without suitable optical system, in most of the cases all be difficult to satisfy lighting and device the performance indications that will reach, also can reduce the efficient of system simultaneously because of the existence of a large amount of invalid light greatly.The light distribution characteristic of led light source can be effectively modulated in design to the secondary optics of LED, makes its optical field distribution satisfy lighting demand on a large scale.In actual illumination; All require even illumination such as projection lamp, reading lamp, venue illumination, indoor illumination; Therefore, LED is outside to be installed specific secondary optics camera lens and could satisfy the actual illumination demand through giving, and make the LED energy-conserving and environment-protective, advantage such as durable finds full expression flexibly.

Summary of the invention

Technical problem to be solved by this invention is to above-mentioned deficiency of the prior art a kind of LED room lighting optical lens to be provided, and it is simple in structure; Reasonable in design, make that the illumination of LED is even, illumination efficiency is high; Widened the field that utilizes of LED; Energy-conserving and environment-protective, result of use is good, is convenient to promote the use of.

For solving the problems of the technologies described above; The technical scheme that the present invention adopts is: a kind of LED room lighting optical lens; It is characterized in that: said optical lens is a rotational symmetry structure; The bottom surface of said optical lens is provided with one makes the emergent ray of LED get into the inside hemisphere face of depression that deviation does not take place lens; Said hemispherical centre of sphere place is equipped with LED; The outer surface of said optical lens is the continuous free form surface that changes of curvature of the trend of control LED emergent ray, and said hemispherical radius is

wherein, and R is the radius of optical lens bottom surface.

Above-mentioned LED room lighting optical lens, said hemispherical radius are

Above-mentioned LED room lighting optical lens, the manufacturing materials of said lens is glass or plastics, the face type of the free form surface of said optical lens changes with the variation of material; Said glass is optical glass.

The present invention compared with prior art has the following advantages: optical lens entity of the present invention bottom surface is that the center has a certain size recessed hemispherical plane; LED is wrapped in depression sphere centre of sphere place; The optical lens outer surface is a free form surface; The curvature of free form surface is obtained by specific algorithm, and is simple in structure, reasonable in design, is easy to realize; The whole lens of the present invention have rotational symmetric characteristics, and the illumination hot spot that therefore obtains is uniform disc; The present invention locates the design of the continuous free form surface that changes of curvature of the trend of control LED emergent ray on inside hemispherical design of depression and the outer surface through the bottom surface; The luminous energy that has guaranteed the LED outgoing can obtain uniform lighting effect at the illumination target place, make LED can be used for occasions such as projection lighting, room lighting, the field that utilizes of further having widened LED; Improved the utilization ratio of LED; Energy-conserving and environment-protective, result of use is good, is convenient to promote the use of.

Through accompanying drawing and embodiment, technical scheme of the present invention is done further detailed description below.

Description of drawings

Fig. 1 is a stereogram of the present invention.

Fig. 2 is a sectional structure sketch map of the present invention.

Fig. 3 is a upward view of the present invention.

Fig. 4 is the sketch map that free form surface and illumination target torus network are divided thought.

Fig. 5 is under the two-dimensional coordinate, the one-to-one relationship figure of each point on free form surface bus and the illumination target radius surface direction.

Fig. 6 confirms the sketch map of each point coordinates of free form surface bus for the tangent line iterative method.

Description of reference numerals:

The 1-optical lens; The 2-hemisphere face; The 3-light source;

4-illumination target face; 5-incident light vector; 6-emergent light vector;

7-method vector; 8-free form surface bus.

The specific embodiment

Like Fig. 1, Fig. 2 and shown in Figure 3; Optical lens 1 according to the invention is a rotational symmetry structure; The bottom surface of said optical lens 1 is provided with one makes the emergent ray of LED get into the inside hemisphere face 2 of depression that deviation does not take place lens; The centre of sphere place of said hemisphere face 2 is equipped with LED; The outer surface of said optical lens 1 is the continuous free form surface that changes of curvature of the trend of control LED emergent ray; The radius of said hemisphere face 2 is

wherein, and R is the radius of optical lens 1 bottom surface.

Like Fig. 1, Fig. 2 and shown in Figure 3; In the present embodiment; The radius of said hemisphere face 2 is glass, optical glass or plastics for the manufacturing materials of said lens 1, and the face type of the free form surface of said optical lens 1 changes with the variation of material.

As shown in Figure 3, the resolution principle of optical lens 1 outer surface free form surface of the present invention is: in the spot light 3 approximate situation of considering refraction down, if free form surface is carried out latticed division, each grid node place has only an incident ray so.Again according to nonimaging optics rim ray principle, through that part of light at each grid edge on the free form surface, through after the system; Will be corresponding to the edge of an infinitesimal face on the target; Through the light of continuous part in the middle of the grid, through after the system, also in the middle continuous distributed of target infinitesimal.Divergence conservation ( Conservation) principle by light source 3 is known; If optical system does not have loss, the divergence of the light source 3 of optical system and target is a conservation so.Consider from energy point of view, on the infinitesimal face that promptly each grid is corresponding with projecting illumination target face 4 after the interior energy of solid angle that light source becomes passes through system fully on the free form surface.According to above-mentioned principle; For the illuminator of given illumination requirement, can illumination target face 4 and free form surface be divided into the grid that number equates, make on the target face little node corresponding one by one with the grid node formation of free form surface; So according to the Snell law; Through the method vector of control free form surface grid node, control the exit direction of each grid node place incident ray, just can realize accurately that the energy in each grid projects on corresponding little.When little self-energy of each target equates, promptly realized even illumination.

To illumination target face 4 is rotational symmetric even lighting problem, only needs under two-dimensional coordinate, to find the solution bus of free form surface during design, and it along 360 ° of rotation symmetries of optical axis direction, can be obtained corresponding free-form surface lens.

Under the two-dimensional case, find the solution optical lens 1 outer surface from 8 time-divisions of free form surface bus, three steps.

At first, the energy that LED is shone half space is divided equally.Spot light 3 is down approximate, and LED constitutes a hemisphere face to the half space end points that emits beam in the space, the light on the hemisphere face unique corresponding on the lens surface free form surface a bit.This moment, the gross energy Φ of radiation of light source was:

$\mathrm{\Φ}=\underset{0}{\overset{2\mathrm{\π}}{\∫}}\mathrm{d\θ}\underset{0}{\overset{\mathrm{\π}/2}{\∫}}I\cos \mathrm{\φ}\sin \mathrm{\φd\φ}=\mathrm{\πI}{\sin }^2\frac{\mathrm{\π}}{2}=\mathrm{\πI}---\left(1\right)$

I is a light intensity on the primary optical axis, and φ is the angle of light and LED primary optical axis.θ is that I (φ) direction light is at the XY plane inner projection of spherical coordinates and the angle of X axle.

Divide thought according to grid shown in the accompanying drawing 4,, need light source projects is carried out five equilibrium to the energy Φ on the free form surface for obtaining the uniform illuminated area of illumination.Because the free form surface that designs is a rotational symmetry structure, therefore can carry out the equipartition of energy along the φ direction, suppose that counting of five equilibrium is N+1, then contained energy can be expressed as in each endless belt:

${\mathrm{\Φ}}_i=\underset{0}{\overset{2\mathrm{\π}}{\∫}}\mathrm{d\θ}\underset{{\mathrm{\φ}}_i}{\overset{{\mathrm{\φ}}_{i+1}}{\∫}}I\cos {\mathrm{\φ}}_i\sin {\mathrm{\φ}}_i\mathrm{d\φ}=\frac{\mathrm{\Φ}}{N}---\left(2\right)$

During as

, release by following formula:

${\mathrm{\φ}}_i=\arcsin \sqrt{i/N},(i=\mathrm{0,1,2}\mathrm{L\; N})---\left(3\right)$

The N+1 that is got on the free form surface bus 8 led light source of naming a person for a particular job is divided into N energy band that equates to the light energy that half space sends along the φ direction.

Secondly, illumination target face 4 is carried out area and is divided equally, and according to illumination target face 4 rotational symmetric characteristics, illumination target face 4 is divided into N the endless belt that area equates, only need carry out the N equal portions to its radius R.Under the two-dimensional coordinate, by plane geometry knowledge, the radius R of j the point that illumination target face 4 is radially divided _jCan be expressed as:

$R_j=R\·\sqrt{j/N}---\left(4\right)$

The one-to-one relationship of each point is shown in accompanying drawing 5 on free form surface bus 8 and illumination target face 4 radial directions.

At last, shown in accompanying drawing 6, according to the energy equipartition principle, free form surface bus 8 is divided into N+1 discrete point by incident ray.Let the normal vector at a point is

The point of the unit vector of the incident light

outgoing light unit vector is

Snell equation under the form of three vectors satisfy the following relationship:

Wherein n is the refractive index of the free-form surface lens material of asking.Know that by this equation the method vector at each node place is unique definite with emergent light vector 6 by the incident light vector 5 of this point.

In accompanying drawing 6, N+1 the discrete point and the Z axle clamp angle of establishing that free form surface bus 8 marked off are respectively φ _i(i=0,1,2...N), any point coordinate (ρ then _iSin φ _i, ρ _iCos φ _i) promptly represent this some place incident light vector

If this is corresponding to a bit (x on the target face _i, z ₀), emergent light vector then Be (x _i-ρ _iSin φ _i, z ₀-ρ _iCos φ _i).By each point place incident light vector

With the emergent light vector

Representation know, as the radical length ρ of each point place _iAfter confirming, each point coordinates and this incident light vector 5 are promptly definite fully with emergent light vector 6, and then this method vector 7 is confirmed.Confirm each node radical length ρ through the tangent line iterative method below _i

Initially choose node S on the free form surface bus 8 ₀, its coordinate confirms that incident light vector 5 does

By it at illumination target face 4 corresponding nodes T ₀Can confirm the outgoing light vector

With above two vector unitsization, can try to achieve this some place method vector by formula (5)

Confirm this tangential equation simultaneously.When interstitial content was abundant, the incident ray at the some place adjacent with this point must intersect with this tangent line.If this intersection point is S ₁, its incident light vector

Also promptly confirm the emergent light vector By a S ₁With illumination target face 4 respective point T ₁Coordinate confirm method vector that in like manner can this adjacent node place

And then definite this tangential equation.Press above method along φ _iDirection iteration is always gone down, and can try to achieve the coordinate (ρ of N+1 point on the bus _iSin φ _i, ρ _iCos φ _i).So far, institute's free form surface bus 8 of asking is promptly confirmed, it can be obtained the free form surface of asking around 360 ° of rotations of axle.

The above; It only is preferred embodiment of the present invention; Be not that the present invention is done any restriction, every technical spirit changes any simple modification, change and the equivalent structure that above embodiment did according to the present invention, all still belongs in the protection domain of technical scheme of the present invention.

Claims (4)

1. LED room lighting optical lens; It is characterized in that: said optical lens (1) is a rotational symmetry structure; The bottom surface of said optical lens (1) is provided with one makes the emergent ray of LED get into the inside hemisphere face (2) of depression that deviation does not take place lens; The centre of sphere place of said hemisphere face (2) is equipped with LED; The outer surface of said optical lens (1) is the continuous free form surface that changes of curvature of the trend of control LED emergent ray; The radius of said hemisphere face (2) is

wherein, and R is the radius of optical lens (1) bottom surface.

2. according to the described LED room lighting of claim 1 optical lens, it is characterized in that: the radius of said hemisphere face (2) is

3. according to the described LED room lighting of claim 1 optical lens, it is characterized in that: the manufacturing materials of said lens (1) is glass or plastics, and the face type of the free form surface of said optical lens (1) changes with the variation of material.

4. according to the described LED room lighting of claim 3 optical lens, it is characterized in that: said glass is optical glass.

Images