CN204005732U - Large visual field corner LED illuminating lens - Google Patents

Abstract

The utility model relates to the secondary optical system technical field of LED illumination, be specifically related to a kind of large visual field corner LED illuminating lens, first surface is Rotational Symmetry free form surface, and for the light refraction that LED is sent, the light after refraction is vertical with the symmetry axis of first surface; The second curved surface is Rotational Symmetry free form surface, and for the light refraction that LED is sent, the light after refraction overlaps with the light that the spot light on the second curved surface symmetry axis sends; The 3rd curved surface is Rotational Symmetry parabola, and its focus is the virtual optical source point of the second curved surface refracted ray; The 5th curved surface, is asymmetric free form surface, makes light after through the 5th curved surface, in target face, form uniform rectangle Illumination Distribution.The utlity model has good light control ability, can in target face, realize needed Illumination Distribution.

Description

Large visual field corner LED illuminating lens

Technical field

The utility model relates to the secondary optical system technical field of LED illumination, is specifically related to a kind of large visual field corner LED illuminating lens.

Background technology

LED is as a kind of new type light source, and due to its high light efficiency, the advantage such as the life-span is long, nonhazardous becomes the product that country is replacing incandescent lamp and widelys popularize in the works.Because the light distribution of LED is lambert's type, if directly apply to illumination, can in target face, form very inhomogeneous Illumination Distribution, cannot meet the requirement of various illumination occasions to light fixture optical property.In order to make LED better be applied to lighting field, need designs secondary optics system to redistribute the light distribution of LED, it can be formed evenly or other specific Illumination Distribution in target face.

Many Uniform Illuminations of realizing LED with lens at present, but in the relatively very large rectangular area of certain direction angle of visual field such as corridor, while using lens to carry out LED secondary light-distribution, owing to there is total reflection phenomenon, the light efficiency of lens can decline along with the increase of the angle of visual field.Therefore prior art, in the occasion of large angle of visual field illumination, can only adopt many LED lamps or reflective optical system, and many LED lantern festivals increase the cost throwing light on, and reflective system is processed relative complex, and cost is higher, and illuminating effect is also bad.

Utility model content

The purpose of this utility model is exactly the deficiency that will solve above-mentioned existing LED secondary lens, provide a kind of can be in corridor etc. large angle of visual field illumination occasion realize Uniform Illumination and keep the large visual field corner LED illuminating lens of high light effect.

For achieving the above object, the large visual field corner LED illuminating lens that the utility model is designed, comprising:

First surface, is Rotational Symmetry free form surface, and for the light refraction that LED is sent, the light after refraction is vertical with the symmetry axis of first surface;

The second curved surface, is Rotational Symmetry free form surface, and for the light refraction that LED is sent, the light after refraction overlaps with the light that the spot light on the second curved surface symmetry axis sends;

The 3rd curved surface, for Rotational Symmetry parabola, its focus is the virtual optical source point of the second curved surface refracted ray, utilizes total reflection principle, for reflecting light reflection afterwards to the direction vertical with the 3rd curved surface symmetry axis through the second curved surface, and the spherical wave that LED is sent is converted to cylindrical wave;

The 5th curved surface, for asymmetric free form surface, the effect of this free form surface is the light of controlling through cylindrical wave after first surface, the second curved surface and the 3rd curved surface, makes this bundle light after through the 5th curved surface, in target face, form uniform rectangle Illumination Distribution;

The 4th curved surface, is plane, for connecting the 3rd curved surface and the 5th curved surface.

Further, the coordinate of putting on described first surface and the second curved surface is calculated by following formula:

Determine the coordinate figure of initial point, initial point is the intersection point of the z axle of curved surface and solid space, calculates the coordinate figure of putting on contour curve by the mode of iteration, sets current known point (x _i-1, z _i-1) normal vector be N=(N _x, N _z), under the contour curve that calculate, any corresponding incident ray and the angle of z axle are θ _i, lower any coordinate figure (x _i, z _i) be:

$\left\{\begin{array}{c}{x}_i=\frac{z_{i-1}+x_{i-1}k}{\cot {\mathrm{\θ}}_i+k}\\ z_i=x_i\cot {\mathrm{\θ}}_i\end{array}\right.---\left(1\right)$

Wherein k=N _x/ N _z, obtain, after all point coordinates on contour curve, contour curve rotating 360 degrees being obtained to the point coordinates of whole curved surface.

Further, described the 5th curved surface is made up of multiple sub-free form surfaces, between two adjacent sub-free form surfaces, is connected by the plane that is parallel to z axle.

Further, on described the 5th curved surface, coordinate points is calculated by following formula:

The minor axis coordinate of putting on the 5th curved surface is identical with the minor axis coordinate of first surface, the second curved surface and the 3rd curved surface, setting minor axis is x axle, on x axle, choose a series of point, the light energy comprising between these points is identical, on plane x=0 or x=X, construct the initial skeleton curve of the 5th curved surface, wherein X is the maximum of the 3rd curved surface (3) x axial coordinate, first sets initial point, by iteration can be in the hope of y axle and the z axial coordinate put on this skeleton curve:

(x in formula _i, z _i) be the coordinate of the calculative point of current iteration, for the corresponding light of current point with skeleton curve institute planar with axle clamp angle, (x _i-1, z _i-1) be more front coordinate, (N _x, N _z) be more front normal vector coordinate, obtaining obtaining next skeleton curve by (2) formula iteration after initial skeleton curve, re-construct initial skeleton curve at the section start of each subsurface, after obtaining all skeleton curves, obtain all subsurfaces by the mode of setting-out, thereby obtain all point coordinates of the 5th curved surface.

The free-form surface lens for LED illumination of the utility model design, these lens are made up of five curved surfaces, first surface, the second curved surface is one group of free form surface that function is identical with the 3rd curved surface, their object is the light of collimation LED, the spherical wave that LED is sent is converted to cylindrical wave, the central shaft of this cylindrical wave is the less length of side of target face place axle, the 4th curved surface is plane, its object is to connect the 3rd curved surface and the 5th curved surface, the 5th curved surface is asymmetrical free form surface, its object is the direction that changes the light of cylindrical wave, thereby in target face, realize uniform rectangular illumination.

The utility model has adopted the free form surface plane of incidence with fully reflecting surface, and the light of LED is converted to cylindrical wave, makes its topology identical with target face, thereby can keep higher light efficiency form rectangular illumination in target face in.The LED secondary optical system of the utility model design, has good light control ability, can in target face, realize needed Illumination Distribution.

Brief description of the drawings

Fig. 1 is overall structure schematic diagram of the present utility model;

Fig. 2 is upward view of the present utility model;

Fig. 3 is the cutaway view of Fig. 1;

Fig. 4 is the concrete top view of implementing in Fig. 1;

Fig. 5 .1 and Fig. 5 .2 are the Illumination Distribution simulation result of the utility model in target face, and in simulation result, abscissa and ordinate are the distance value of illuminated area.

In figure, first surface 1, the second curved surface 2, the three curved surface 3, the four curved surface 4, the five curved surfaces 5.

Detailed description of the invention

Below in conjunction with the drawings and specific embodiments, the utility model is described in further detail:

Large visual field corner LED illuminating lens shown in Fig. 1-4, comprise: first surface 1, for Rotational Symmetry free form surface, for the light refraction that LED is sent, light after refraction is vertical with the symmetry axis of first surface 1, and the LED light of this free form surface control and the angle of z axle are determined by the refractive index of lens material; The second curved surface 2, is Rotational Symmetry free form surface, and for the light refraction that LED is sent, the light after refraction overlaps with the light that the spot light on the second curved surface symmetry axis sends; The 3rd curved surface 3, for Rotational Symmetry parabola, its focus is the virtual optical source point of the second curved surface refracted ray, utilizes total reflection principle, for reflecting light reflection afterwards to the direction vertical with the 3rd curved surface 3 symmetry axis through the second curved surface, and the spherical wave that LED is sent is converted to cylindrical wave; The 5th curved surface 5, for asymmetric free form surface, the effect of this free form surface is the light of controlling through cylindrical wave after first surface 1, the second curved surface 2 and the 3rd curved surface 3, makes this bundle light after through the 5th curved surface 5, in target face, form uniform rectangle Illumination Distribution; The 4th curved surface 4, is plane, for connecting the 3rd curved surface 3 and the 5th curved surface 5.

First surface 1, the second curved surface 2 and the 3rd curved surface 3 are planes of incidence of LED light, and object is that the spherical wave collimation that LED is sent is the cylindrical wave taking target face minor face place reference axis as symmetry axis.

Free form surface S1 is Rotational Symmetry free form surface, only need calculate a contour curve while therefore calculating, then revolves to turn around around symmetry axis axle to obtain the face type of first surface 1, and its effect is to vertical with its symmetry axis by the light refraction from LED.While calculating contour curve, first determine the coordinate figure of initial point, initial point is the intersection point of the z axle of curved surface and solid space, calculates the coordinate figure of putting on contour curve by the mode of iteration, sets current known point (x _i-1, z _i-1) normal vector be N=(N _x, N _z), under the contour curve that calculate, any corresponding incident ray and the angle of z axle are θ _i, lower any coordinate figure (x _i, z _i) be:

$\left\{\begin{array}{c}{x}_i=\frac{z_{i-1}+x_{i-1}k}{\cot {\mathrm{\θ}}_i+k}\\ z_i=x_i\cot {\mathrm{\θ}}_i\end{array}\right.---\left(3\right)$

Wherein k=N _x/ N _z, obtain, after all point coordinates on contour curve, contour curve rotating 360 degrees being obtained to the point coordinates of whole curved surface.

The 5th curved surface 5 is made up of multiple sub-free form surfaces, between two adjacent sub-free form surfaces, is connected by the plane that is parallel to z axle.On the 5th curved surface 5, coordinate points is calculated by following formula:

On the 5th curved surface 5, the minor axis coordinate of point is identical with the minor axis coordinate of first surface 1, the second curved surface 2 and the 3rd curved surface 3, setting minor axis is x axle, on x axle, choose a series of point, the light energy comprising between these points is identical, on plane x=0 or x=X, construct the initial skeleton curve of the 5th curved surface 5, wherein X is the maximum of point coordinates on x axle, first sets initial point, and y axle and the z axial coordinate on this skeleton curve, put are:

(x in formula _i, z _i) be the coordinate of the calculative point of current iteration, for the corresponding light of current point with skeleton curve institute planar with axle clamp angle, (x _i-1, z _i-1) be more front coordinate, (N _x, N _z) be more front normal vector coordinate, obtaining obtaining next skeleton curve by (2) formula iteration after initial skeleton curve, re-construct initial skeleton curve at the section start of each subsurface, after obtaining all skeleton curves, obtain all subsurfaces by the mode of setting-out, thereby obtain all point coordinates of the 5th curved surface 5.

The z coordinate figure of initial point of setting first surface 1 is 5mm, and the corresponding LED light of curved edges and z axle clamp angle are 30 °, according to formula (1), and 1 of the first surface that calculates coordinate a little.

The object of the second curved surface 2 be make the reverse extending line of light that LED the sends emergent ray after this curved surface refraction meet at x axle a bit, thereby obtain a virtual optical source point.The initial point of the second curved surface 2 is the marginal point of first surface 1, uses equally (1) when calculating.

The focus of the 3rd curved surface 3 is the virtual optical source point that the second curved surface 2 is created, and utilizes total reflection principle, in the future the light reflection of the second curved surface 2 to symmetry axis vertical direction.

The 4th curved surface 4 is plane, for connecting the 3rd curved surface 3 and the 5th curved surface 5.

The energy by the cylindrical wave through after first surface 1, the second curved surface 2 and the 3rd curved surface 3 of the 5th curved surface 5 is redistributed, and makes to form uniform rectangle Illumination Distribution on objective plane.In this enforcement, target setting face is that the length of side is 8m × 2m and the rectangle vertical with z axle, and target face central point is positioned on z axle and apart from LED light source (origin of coordinates) 2.2m.Adopt the conservation of energy and Snell's law to calculate the coordinate of putting on free form surface.First will be divided into the grid that energy is equal through cylindrical wave and illumination target face after first surface 1, the second curved surface 2 and the 3rd curved surface 3 according to the conservation of energy.After obtaining this corresponding relation, according to Snell's law, set the 5th curved surface 5, the second curved surface 2 and the 3rd curved surface 3 and calculate initial point, the height of initial point should be slightly larger than the height of the 3rd curved surface 3.Adopt the mode of iteration to obtain the coordinate of point on the 5th curved surface 5.For the error that reduces to produce in iterative process, adopt the mode of patch to construct the 5th curved surface 5, between each patch, use plane to connect.

After calculating all curved surfaces of free-form surface lens, height is 23.31mm, and long is 20.40mm, and wide is 16.11mm.The space height forming between first surface 1, the second curved surface 2 is 5mm, and wide is 4.20mm, for placing LED light source.

The lens that Fig. 5 .1 and Fig. 5 .2 are this enforcement are the Illumination Distribution result in target face in optical simulation software, obtain by 1,000,000 light of trace, wherein Fig. 5 .1 is the Illumination Distribution in target face, in figure, gray value size is directly proportional to brightness value, and Fig. 5 .2 is the Illumination Distribution on two centre coordinate axles in target face.Wherein the optical efficiency of lens is 85%, and the light efficiency of single free-form surface lens under same design parameter is only 70%.In target face, the illumination uniformity on long limit and minor face is 87.7% and 89.3% simultaneously, and uniformity is better.

Claims (2)

1. a large visual field corner LED illuminating lens, is characterized in that comprising:

First surface (1), is Rotational Symmetry free form surface, and for the light refraction that LED is sent, the light after refraction is vertical with the symmetry axis of first surface (1);

The second curved surface (2), is Rotational Symmetry free form surface, and for the light refraction that LED is sent, the light after refraction overlaps with the light that the spot light on the second curved surface symmetry axis sends;

The 3rd curved surface (3), for Rotational Symmetry parabola, its focus is the virtual optical source point of the second curved surface refracted ray, utilize total reflection principle, for reflecting light reflection afterwards to the direction vertical with the 3rd curved surface (3) symmetry axis through the second curved surface, and the spherical wave that LED is sent is converted to cylindrical wave;

The 5th curved surface (5), for asymmetric free form surface, the effect of this free form surface is to control through first surface (1), the second curved surface (2) and the 3rd curved surface (3) light of cylindrical wave afterwards, makes this bundle light in target face, form afterwards uniform rectangle Illumination Distribution through the 5th curved surface (5);

The 4th curved surface (4), is plane, for connecting the 3rd curved surface (3) and the 5th curved surface (5).

2. large visual field according to claim 1 corner LED illuminating lens, is characterized in that: described the 5th curved surface (5) is made up of multiple sub-free form surfaces, between two adjacent sub-free form surfaces, is connected by the plane that is parallel to z axle.