CN204922845U - A wide -angle lens for near field uniform illumination - Google Patents

Abstract

The utility model provides a wide -angle lens for near field uniform illumination contains interior concave surface, outer convex surface, bottom surface and locating support, interior concave surface is the light source incident surface, should be interim discontinuous curved surface by interior concave surface, disperses the incident beam, outer convex surface should confirm by the distribution of outgoing light intensity that this outgoing light intensity can be tried to achieve according to the conservation of energy formula by outer convex surface for going out the plain noodles, and the evagination is controlled in the face of the emergent ray orientation, the bottom surface is the plane of reflection. This kind of lens can effectively increase big light -emitting diodes's light -emitting angle, improve target face edge illuminance. Make and adopt this kind of lens not only can reduce emitting diode's the use quantity and the distance of target face, from reducing manufacturing cost to a certain extent, can also guarantee the illumination uniformity nature of target face.

Description

For the wide-angle lens of near-field uniform illumination

Technical field

The utility model belongs to optical lens field, is specifically related to the wide-angle lens of a kind of near-field uniform illumination.

Background technology

In recent years, light emitting diode has the good and low power consumption and other advantages of high efficiency, Photochromic Properties, is widely used in indoor and outdoor lighting and backlight, wherein very general with the application of the panel light of flat luminous form, advertising lamp box and display.

Distinguish from structure, flat luminous application is divided into side entering type and straight-down negative two kinds of lighting systems.Side entering type illumination needs to adopt light guide plate to be reflected away by the incident ray of light emitting diode.Side entering type illumination small volume, light guide plate technology is comparatively ripe.But also exist between light emitting diode and light guide plate that coupling efficiency is low, cost is high and the size-constrained system of exiting surface, be more suitable for small size bright dipping, as mobile phone, computer display screen, panel computer etc.Light emitting diode is directly arranged in bottom target face by the illumination of tradition straight-down negative, due to light emitting diode approximate Lambertian type illuminator, illumination can decay rapidly along with the increase of distance, cause the Overlay of edge illumination unsatisfactory, therefore straight-down negative illumination needs high-density arrangement light emitting diode could form the effect of even bright dipping in target face, but easily increases cost and thickness.

Therefore, effectively reduce the usage quantity of straight-down negative illumination light-emitting diode, reduce the thickness of flat luminous form simultaneously, realize ultrathin and exiting surface uniform-illumination, and reduce production cost to a certain extent, become the problem needing solution in current industry badly.

Utility model content

For defect existing in direct-light-type backlight in prior art, the utility model provides a kind of wide-angle lens for near-field uniform illumination, effectively can overcome the above problems, and can be applicable to the light emitting diode with larger area.

In order to achieve the above object, a kind of wide-angle lens for near-field uniform illumination that the utility model provides, comprises inner concave, outer convex surface, bottom surface and locating support; Described inner concave is light source incidence face, and this inner concave is interim discontinuous surfaces, disperses incident ray; Described outer convex surface is exiting surface, and this outer convex surface is distributed by output intensity and determines, this output intensity can be tried to achieve according to conservation of energy formula, and evagination controls in the face of emergent ray direction; Described bottom surface is reflecting surface.

In a preferred embodiment: the inner concave of described lens and outer convex surface are respectively about central shaft Rotational Symmetry.

In a preferred embodiment: described inner concave is interim discontinuous surfaces, this interim discontinuous surfaces, by determining target face height, is obtained by the conservation of energy formulae discovery of non-imaged theory.

In a preferred embodiment: described interim discontinuous surfaces is made up of multi-disc free form surface.

In a preferred embodiment: described conservation of energy formula can be expressed as:

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

Wherein I (θ) is output intensity distribution, and θ is beam projecting angle, and φ is light source total light flux, and N is decile number.

In a preferred embodiment: described output intensity distribution I (θ) can be expressed as

I(θ)＝a ₀+a ₁θ ²+a ₂θ ⁴+a ₃θ ⁶+a ₄θ ⁸

Wherein a0, a2, a4, a6 are function known variables.

In a preferred embodiment: output intensity distribution I (θ) and field of illumination illumination E (θ) close and be

$E\left(\mathrm{\θ}\right)=\frac{I\left(\mathrm{\θ}\right)cos\mathrm{\θ}}{r^2}$

Wherein r is along the distance of emergent ray from light source to target face.

In a preferred embodiment: described field of illumination illumination E (θ) can be obtained according to the minimum of a value of root-mean-square error and test point mean value, and the minimum of a value according to root-mean-square error and test point mean value is expressed as:

$Min=\frac{\sqrt{\underset{i=1}{\overset{N}{\Σ}}\frac{E{\left(\mathrm{\θ}\right)}^2}{N}}}{E\left(\mathrm{\θ}\right)}N$

In a preferred embodiment: described bottom surface is with micro-structural.

In a preferred embodiment: described micro-structural is inverted pyramid or frosted or multistage step or hemisphere or irregular ripple.

The wide-angle lens of a kind of near-field uniform illumination that the utility model provides, take the beneficial effect after such scheme to be:

This kind of lens effectively can increase the rising angle of light emitting diode, improve target face edge illumination.Make to adopt this kind of lens not only can reduce the usage quantity of light emitting diode and the distance of target face, reduce production cost to a certain extent, the illuminance uniformity of target face can also be ensured.

Accompanying drawing explanation

The structural representation of the wide-angle lens of Fig. 1 the utility model near-field uniform illumination;

The generalized section of the wide-angle lens of Fig. 2 the utility model near-field uniform illumination;

In Fig. 3 embodiment, bottom surface is containing the lens profile figure of micro-structural;

Illumination Distribution figure in Fig. 4 embodiment on target face field of illumination;

The surface of intensity distribution in Fig. 5 embodiment on target face field of illumination;

In figure:

1-light emitting diode 2-inner concave

The outer convex surface 4-bottom surface of 3-

5-locating support 6-target face

7-micro-structural.

Detailed description of the invention

In order to explain the technical solution of the utility model further, be described in detail below in conjunction with accompanying drawing.

Lens shown in Fig. 1 and Fig. 2 are the wide angle optical lens of a kind of near-field uniform illumination of the utility model, adopt refractive index to be the transparent material of 1.45-1.6, are formed by Shooting Technique manufacture.Material is not limited to Merlon (PC), polymethyl methacrylate (PMMA).

As shown in Figure 2, in this example, wide-angle lens is around Z axis Rotational Symmetry.Described optical lens, comprises inner concave 2, outer convex surface 3, bottom surface 4, locating support 5 and micro-structural 7.Described light emitting diode 1 is placed in immediately below lens bottom centre axle, and light source luminescent face flushes with bottom surface.Described inner concave 2 is light source incidence face, and this inner concave 2 is interim discontinuous surfaces, disperses incident ray; Described outer convex surface 3 is exiting surface, and this outer convex surface 3 is distributed by output intensity and determines, this output intensity can be tried to achieve according to conservation of energy formula, and evagination controls in the face of emergent ray direction; Described bottom surface is reflecting surface.

Target face is placed in 30mm place directly over light source luminescent surface.The light distribution approximate Lambertian type that light emitting diode sends, outgoing beam is by reflecting by outer convex surface 3 after inner concave 2 homogenous diffusion again, most of incident ray is refracted to target face with wide-angle by outer convex surface 3 again, fraction incident ray then reflexes to bottom surface 4, bottom surface 4 is connected with inner concave with outer convex surface, reflection ray, containing micro-structural, is reflexed to target face 6 by bottom surface 4 again.

Described conservation of energy formula can be expressed as:

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

Wherein I (θ) is output intensity distribution, and θ is beam projecting angle, and φ is light source total light flux, and N is decile number.

Described output intensity distribution I (θ) can be expressed as

I(θ)＝a ₀+a ₁θ ²+a ₂θ ⁴+a ₃θ ⁶+a ₄θ ⁸

Wherein a0, a2, a4, a6 are function known variables.

In a preferred embodiment: output intensity distribution I (θ) and field of illumination illumination E (θ) close and be

$E\left(\mathrm{\θ}\right)=\frac{I\left(\mathrm{\θ}\right)cos\mathrm{\θ}}{r^2}$

Wherein r is along the distance of emergent ray from light source to target face.

Described field of illumination illumination E (θ) can be obtained according to the minimum of a value of root-mean-square error and test point mean value, and the minimum of a value according to root-mean-square error and test point mean value is expressed as:

$Min=\frac{\sqrt{\underset{i=1}{\overset{N}{\Σ}}\frac{E{\left(\mathrm{\θ}\right)}^2}{N}}}{E\left(\mathrm{\θ}\right)}N$

The utility model inner sunken face 2 is spliced for multi-disc discontinuous surfaces, the radius of inner concave constantly expands from top to bottom, decline in staged, and the curvature of each curved surface is different, mainly the emergent ray of light source is carried out large angle scattering uniformly, curved surface data is obtained by non-imaged theoretical energy conservation formulae discovery.

This example preferably, is spliced by 5 discontinuous surfaces, and maximum inner concave curved surface diameter is 5.84mm, and inner concave height is 3.2mm, is applicable to Large area light source, is not limited to paster light source 3030,3528.

The outer convex surface 3 of the utility model is free form surface, outer convex surface 3 is primarily of light source size and target face distance dependent, emergent ray by inner concave 2 is refracted to target face 6 assigned address, again increase rising angle, curved surface data is obtained by non-imaged theoretical energy conservation formulae discovery.This example preferably, is calculated by paster light source 3030, and outer convex surface peak is 4mm.

The utility model adopts micro-structural 7 to be located on bottom surface 4, makes the total reflection light line reflection of outer convex surface 3 carry out diffuse reflection to during bottom surface 4, reduces the illumination of central shaft, and the dissipation and the multiple reflections that reduce light absorb, and improve illuminance uniformity and the light extraction efficiency of target face.This example micro-structural 7 adopts inverted pyramid, and the preferred length of side is 0.5mm, is highly 0.3mm.

The utility model adopts locating support 5, locating support is located at towards LED bottom, it is peripheral that locating support is located at the outer convex surface maximum gauge of lens, plays the effect of a positioned light source center and restriction bottom surface 4 and light source surface distance, ensure the optical property of wide-angle lens with this.This example preferably, diameter 1.5mm, height 3mm cylinder.

The rising angle of the utility model wide-angle lens reaches 160 °, and effectively increase the rising angle of light emitting diode, and lens maximum radius is 8.75mm, lens volume is little.This kind of lens can improve target face edge illumination, make to adopt this kind of lens not only can reduce the usage quantity of light emitting diode and the distance of target face, reduce production cost to a certain extent, can also ensure the illuminance uniformity of target face.

The above; be only the utility model preferably detailed description of the invention; but protection domain of the present utility model is not limited thereto; anyly be familiar with those skilled in the art in the technical scope that the utility model discloses; the change that can expect easily or replacement, all should be encompassed within protection domain of the present utility model.Therefore, protection domain of the present utility model should be as the criterion with the protection domain of claim.

Claims (6)

1., for a wide-angle lens for near-field uniform illumination, it is characterized in that: comprise inner concave, outer convex surface, bottom surface and locating support; Described inner concave is light source incidence face, and this inner concave is interim discontinuous surfaces, disperses incident ray; Described outer convex surface is exiting surface, and this outer convex surface is distributed by output intensity and determines, this output intensity can be tried to achieve according to conservation of energy formula, and evagination controls in the face of emergent ray direction; Described bottom surface is reflecting surface.

2. as claimed in claim 1 a kind of for near-field uniform illumination wide-angle lens, it is characterized in that: the inner concave of described lens and outer convex surface are respectively about central shaft Rotational Symmetry.

3. as claimed in claim 1 a kind of for near-field uniform illumination wide-angle lens, it is characterized in that described inner concave is interim discontinuous surfaces, this interim discontinuous surfaces, by determining target face height, is obtained by the conservation of energy formulae discovery of non-imaged theory.

4. as claimed in claim 3 a kind of for near-field uniform illumination wide-angle lens, it is characterized in that: described interim discontinuous surfaces is made up of multi-disc free form surface.

5. as claimed in claim 1 a kind of for near-field uniform illumination wide-angle lens, it is characterized in that: described bottom surface is with micro-structural.

6. a kind of wide-angle lens for near-field uniform illumination as claimed in claim 5, is characterized in that: described micro-structural is inverted pyramid or frosted or multistage step or hemisphere or irregular ripple.