WO2016045176A1

WO2016045176A1 - Method for designing full-periphery light distribution lens and corresponding light distribution lens

Info

Publication number: WO2016045176A1
Application number: PCT/CN2014/091149
Authority: WO
Inventors: 陈必寿; 许礼; 姜玉稀; 刘海波
Original assignee: 上海三思电子工程有限公司; 上海三思科技发展有限公司; 嘉善三思光电技术有限公司
Priority date: 2014-09-23
Filing date: 2014-11-14
Publication date: 2016-03-31
Also published as: CN104613416A; CN104296071A; CN104613416B

Abstract

A method for designing a full-periphery light distribution lens and the corresponding light distribution lens. The method comprises: arranging multiple LED ring strips (1) and secondary light distribution lenses (2) surrounding the LED ring strips (1); using the optical axis plane of any LED ring strip as an incident plane, equally dividing the light source angle of the LED ring strip on one side of the optical axis into N small angles and N small sections of the corresponding light distribution curve according to the distribution rule of the light intensity versus the light-emitting angle, the edge small section of the N small sections being used as an initial irradiated small section, and an edge point being used as an initial irradiated point; calculating two continuous curves corresponding to each LED ring strip, connecting the respective curves to form a closed curve, then rotating the closed curve to form the three-dimensional shape of the full-periphery light distribution lens. The full-periphery light distribution illumination with the angle larger than 180 degrees can be achieved.

Description

Design method of full-period light distribution lens and corresponding light distribution lens

Technical field

The invention relates to a lens design method, in particular to a design method and a corresponding light distribution lens of a full-circumferential light distribution lens capable of realizing light distribution greater than 180 degrees.

Background technique

LED (Light Emitting Diode) has become the most competitive new light source in the 21st century due to its high efficiency, pure light color, low energy consumption, long life and no pollution. With the continuous improvement of LED luminous flux and light efficiency, LEDs are increasingly used in the field of lighting. However, the surface of the LED chip is Lambertian, and its light-emitting angle is only 120 degrees. It cannot be directly applied to the lighting system, and only through its reasonable secondary light distribution can meet different lighting needs.

At present, the secondary light distribution design of the LED light source on the market is mainly a projection type reflector and a lens. Since the light distribution beam angle is less than 180 degrees, only a single surface planar projection illumination can be realized, and the entire space cannot be realized. Three-dimensional lighting, if used in indoor lighting, it is easy to form a dark corner of the corner or ceiling lighting, which seriously affects the eye comfort of the human body.

Summary of the invention

In view of the deficiencies in the prior art, it is an object of the present invention to provide a method of designing a full-circumferential light distribution lens.

The technical problem solved by the present invention is that a stepped ring circular stage free-form surface lens is used as shown in FIG. 1 , instead of the prior art projection type reflector or lens as shown in FIG. 2 , a full-circumference light distribution with a beam angle greater than 180 degrees is realized. design.

A method for designing a full-circumferential light distribution lens according to the present invention includes the following steps:

Step 1: setting a plurality of LED loops and a secondary light distribution lens surrounding the LED loops;

Each LED ring strip is mainly composed of an LED light source arranged in a circle in a plane;

The envelope surface of the plurality of LED ring strips is a round table side;

The light distribution curve formed by the secondary light distribution lens is divided into a plurality of portions equal to the number of LED loops, and the plurality of portions are in one-to-one correspondence with the plurality of LED loop strips;

The light distribution angle of the partial light distribution curve is less than 180 degrees, and the light distribution angle of the partial light distribution curve is greater than or equal to 180 degrees, and the proportion of the light flux included in each part of the light distribution curve is equal to the total light flux ratio of each LED ring band;

Step 2: taking the plane of the optical axis of any one of the LED coils as the incident surface, and on the incident surface, dividing the angle of the light source of the LED ring on the optical axis into N small angles, wherein N≥4, that is, each The angles of the light sources are distributed at equal angular intervals;

Step 3: The light distribution curve separated by step 1 is divided into N small segments, and the corresponding luminous flux of each segment in the N-segment light distribution curve is equal to the luminous flux of the light source distributed in step 2;

Step 4: The N small angles are respectively corresponding to the N small segments of the light distribution curve;

Step 5: taking the edge segment of the N segments as the starting segment, and starting the segment with the edge point, that is, corresponding to one of the N small corners;

Step 6: Find two consecutive curves corresponding to each LED band;

Step 7: The two consecutive curves corresponding to the LED strips are sequentially connected end to end to form a closed curve, and then the closed curve is rotated around the central axis of the LED light source of the LED ring to form a full-circumference light distribution. The three-dimensional shape of the optical lens;

Wherein, the step 6 includes the following steps:

Step 6.1: according to the distance requirement of the lens entrance surface of the full-circumferential light distribution lens to leave the light source, take a point on the incident light corresponding to the initial illuminated point as the starting feature point of the lens entrance surface, At a starting feature point on the light incident surface, a line parallel to the line connecting the LED light source and the initial illuminated point forms an angle with the incident light, which is the initial light deflection angle of the secondary light distribution lens. The initial ray deflection angle is divided into a first deflection angle and a second deflection angle. The angular division of the first deflection angle and the second deflection angle is used as a refracting line of the incident ray passing through the lens entrance surface, and the refraction law and the corresponding a small angle of the N small angles is obtained, and a second feature point on the light incident surface adjacent to the initial feature point on the light incident surface is obtained, and the second feature point on the light incident surface corresponds to the initial illumination Pointing adjacent second illuminated points;

Step 6.2: Perform step 6.1 for each of the N small segments, and sequentially determine the positions of the feature points on the light incident surface of the lens corresponding to each of the N small segments:

Step 6.3: taking a point on the refracting line after passing the initial feature point on the light incident surface of the lens, according to the lens thickness requirement of the secondary light distribution lens, as the lens exit surface of the full-circumferential light distribution lens At the starting feature point, the position of each feature point on the light exit surface of the lens is obtained as follows:

Step i1: at a starting feature point on the light-emitting surface, a line parallel to the line connecting the LED light source and the initial illuminated point forms an angle with the incident light, which is a starting light deflection angle of the secondary light distribution lens, The initial ray deflection angle is divided into a first deflection angle and a second deflection angle, and the angular division of the first deflection angle and the second deflection angle is used as a refracting line of the incident ray passing through the illuminating surface of the lens, and the law of refraction is Corresponding to one of the N small corners a small angle, a second feature point on the light-emitting surface adjacent to the starting feature point on the light-emitting surface is obtained, and the second feature point on the light-emitting surface corresponds to the second illuminated point adjacent to the initial illuminated point ;

Step i2: performing step i1 for each of the N small segments, and sequentially determining the positions of the feature points on the lens light-emitting surface corresponding to each of the N small segments;

Step 6.4: sequentially connecting the feature points on the light incident surface of the lens, and sequentially connecting the feature points on the light exiting surface of the lens to form two continuous curves.

Preferably, the feature points are sequentially connected by a straight line or a smooth curve.

Preferably, the number of LED loops is two, and the light distribution curve formed by the secondary light distribution lens is divided into two parts, wherein a light distribution angle of a part of the light distribution curve is less than 180 degrees, and another part of the light distribution curve The light distribution angle is greater than or equal to 180 degrees.

According to the present invention, a full-circumferential light distribution lens is obtained according to the above-described design method of a full-circumferential light distribution lens.

Preferably, the full-circumferential light distribution lens has a through hole in the middle thereof.

Compared with the prior art, the present invention has the following beneficial effects:

(1) Full-perimeter light distribution illumination greater than 180 degrees can be achieved;

(2) The method of determining the surface of the lens by calculating the feature points can determine the shape of the inner and outer surfaces of the lens more accurately and quickly;

(3) The form of integral lens light distribution avoids the influence of single lens assembly on light distribution.

DRAWINGS

Other features, objects, and advantages of the present invention will become apparent from the Detailed Description of Description

Figure 1 is an outline view of a conventional projection lens;

2 is an overall structural view of a full-circumference light distribution system;

3 is a sectional view of a light distribution curve of a full-circumferential light distribution lens;

4 is a schematic view showing a method of dividing a small angle on an incident surface;

FIG. 5 is a schematic diagram of a method for dividing a small section in an outgoing light distribution space; FIG.

6 is a schematic view for determining feature points on a surface of a lens and sequentially connecting them;

Figure 7 is a cross-sectional view of the stepped truncated cone lens of Embodiment 1;

Figure 8 is an external view of a stepped truncated freeform lens of Embodiment 1;

Figure 9 is a cross-sectional view showing a stepped truncated cone lens of Embodiment 2;

Figure 10 is a perspective view showing the stepped truncated free-form surface lens of the second embodiment.

detailed description

The invention will now be described in detail in connection with specific embodiments. The following examples are intended to further understand the invention, but are not intended to limit the invention in any way. It should be noted that a number of variations and modifications may be made by those skilled in the art without departing from the inventive concept. These are all within the scope of protection of the present invention.

The present invention is directed to constructing a light distribution method that achieves full-circumference light distribution greater than 180 degrees. The light distribution method includes an annularly arranged LED light source 1 and a secondary light distribution lens 2, as shown in FIG. The LED light source 1 is arranged in a plurality of annular loops on different horizontal planes, and forms a three-dimensional array of annular stacks in a three-dimensional space at a certain conical angle; the secondary light distribution lens 2 has a stepped truncated cone shape. Stepped circular table free-form lens (Figure 2), the design steps are as follows:

a) According to the number of loops of the LED light source, the light distribution curve formed by the secondary light distribution lens 2 is divided into an equal number of portions. For example, in FIG. 2, the LED light sources are arranged in two annular loops, and the light distribution curve formed by the secondary light distribution lens 2 is also divided into two parts, wherein a part of the light distribution curve has a light distribution angle of less than 180 degrees, and the other part The light distribution angle of the light distribution curve is greater than or equal to 180 degrees. When the light distribution curve is divided into three or more parts, the light distribution angles of the three parts can be arbitrarily distributed, as long as the principle of conservation of energy with the LED circle is ensured. (As shown in Fig. 3, L1 represents a light distribution portion of less than 180 degrees, L2 represents a light distribution portion of more than 180 degrees), and the ratio of the luminous flux contained in the two portions of the light distribution curve is equal to the total luminous flux ratio of the LED light source of each of the coils. The design of the lens will be separately designed for the divided light distribution curves;

b) forming an optical axis plane of the LED light source ring with any one of the ring-shaped LED light sources as an incident surface, and dividing the light source angle of the optical axis side into N small angles on the incident surface, wherein N≥4, that is, each The source angles are assigned at equal angular intervals. In order to make the figure clear, this embodiment takes N=4, that is, it is divided into 4 small angles, which are ɑ1, ɑ2, ɑ3, ɑ4, respectively. ;

c) dividing the light distribution curve separated by step a) (that is, the distribution of light intensity with the angle of illumination) into four sub-sections, respectively, corresponding to the luminous flux of each of the ab, bc, cd, de, and 4-segment light distribution curves The angular flux of each source separated from step b) is equal;

d) aligning the four small corners of the LED light source ring with the four small segments of the light distribution curve;

e) taking the ab small segment as the starting small segment, starting from the point a, the corresponding small angle of the ab segment is ɑ1, according to the distance requirement of the lens entering the light surface 201 leaving the light source, corresponding to the point a A point 1a is taken as the starting feature point on the incident surface of the lens, and at the starting feature point, parallel to the light source and the initial illuminated point a The line connecting the line forms an angle β1 with the incident light, which is the initial light deflection angle of the lens, and divides the initial light deflection angle β1 into a first deflection angle β11 and a second deflection angle β12, and the two deflection angles The ratio can be arbitrary. In this embodiment, β11:β12=1:1, and the angular line is taken as the incident light passing through the light incident surface (the light incident surface 201 and the light exit surface 202 of the lens respectively refer to the inner surface and the outer surface of the lens). The refracting line after the characteristic point 1a is determined by the law of refraction to determine the normal line n1 of the point 1a, and the line perpendicular to the normal line n1 forms an intersection with the incident surface of the light, which intersects with the corner of the small corner ɑ1 The intersection points are 1a and 1b, respectively, and the 1b point is the second feature point. On the second illuminated segment bc, the b point is taken as the second illuminated point, and the b point corresponds to the second feature point 1b. According to the above method, as long as the normal line of each sign is obtained, each feature point can be obtained--the specific method for solving the normal of each feature point is as follows: 1. The feature is obtained by the incident light direction of the feature point. The incident vector Nin of the point; 2. The refractive index Nrefract of the feature point is obtained by the direction of the refracted ray of the feature point; 3. The normal vector of each feature point can be obtained by the following vector expression of the law of refraction: Nf=n *Nrefract–n0*Nin; where Nf is the normal vector of the feature point, n is the refractive index of the medium where the ray is refracted, and n0 is the refractive index of the medium where the incident ray is located.

f) in the same step as above, sequentially determining the positions of the feature points 1c, 1d, 1e on the lens entrance surface 201 corresponding to the respective illuminated points c, d, e of the four segments;

g) taking a point 2a according to the lens thickness requirement on the refracting line after passing through the starting feature point 1a on the lens entrance surface 201, as the starting feature point on the lens exit surface 202, adopting and obtaining the illuminating surface A similar method is used to determine the position of each feature point on the light exiting surface 202 of the lens; specifically:

According to the requirement of the thickness of the full-circumferential light distribution lens, a point 2a is taken as a starting feature point on the light-emitting surface 202 on the refracting line passing through the initial feature point 1a on the light-incident surface, and the refracting line is used as the lens light-emitting surface. The incident ray of 202 is a refracting line of the lens exit surface 202 parallel to the line connecting the illuminated point a and the light source at the point 2a, and the direction of the incident ray and the refracting line is the second offset angle β12 of the figure. In the two corner directions, the positions of the

feature points

2b, 2c, 2d, and 2e on the second surface are sequentially determined in exactly the same manner as the feature points for determining the light incident surface.

h) sequentially connecting the feature points on the light-incident surface 201 and the light-emitting surface 202 to form two continuous curves;

i) with the above steps, find another circle with LED light source to form two continuous curves 203 and 204 corresponding to the LED light source ring;

j) The four curves are connected in pairs to form a closed curve, and the central axis 205 of the circled light source is rotated to form a three-dimensional shape of the lens.

In another embodiment of the present invention, in order to achieve a better heat dissipation effect, the lens can also be designed as a middle belt through hole in the shape of a middle band through hole. In design, the full circumference light distribution lens The principle of optical design is the same as the first The method of an embodiment is only designed from the position edge of the central band through hole, and the optical curve is obtained, and then connected, and then rotated around the central axis to form a stereoscopic switch of the lens, as shown in FIG. 9 and FIG.

The specific embodiments of the present invention have been described above. It is to be understood that the invention is not limited to the specific embodiments described above, and various modifications and changes may be made by those skilled in the art without departing from the scope of the invention.

Claims

A method for designing a full-circumferential light distribution lens, comprising the steps of:

Step 1: setting a plurality of LED loops and a secondary light distribution lens surrounding the LED loops;

Each LED ring strip is mainly composed of an LED light source arranged in a circle in a plane;

The envelope surface of the plurality of LED ring strips is a round table side;

The light distribution curve formed by the secondary light distribution lens is divided into a plurality of portions equal to the number of LED loops, and the plurality of portions are in one-to-one correspondence with the plurality of LED loop strips;

The light distribution angle of the partial light distribution curve is less than 180 degrees, and the light distribution angle of the partial light distribution curve is greater than or equal to 180 degrees, and the proportion of the light flux included in each part of the light distribution curve is equal to the total light flux ratio of each LED ring band;

Step 2: taking the plane of the optical axis of any one of the LED coils as the incident surface, and on the incident surface, dividing the angle of the light source of the LED ring on the optical axis into N small angles, wherein N≥4, that is, each The angles of the light sources are distributed at equal angular intervals;

Step 3: The light distribution curve separated by step 1 is divided into N small segments, and the corresponding luminous flux of each segment in the N-segment light distribution curve is equal to the luminous flux of the light source distributed in step 2;

Step 4: The N small angles are respectively corresponding to the N small segments of the light distribution curve;

Step 5: taking the edge segment of the N segments as the starting segment, and starting the segment with the edge point, that is, corresponding to one of the N small corners;

Step 6: Find two consecutive curves corresponding to each LED band;

Step 7: The two consecutive curves corresponding to the LED strips are sequentially connected end to end to form a closed curve, and then the closed curve is rotated around the central axis of the LED light source of the LED ring to form a full-circumference light distribution. The three-dimensional shape of the optical lens;

Wherein, the step 6 includes the following steps:

Step 6.1: according to the distance requirement of the lens entrance surface of the full-circumferential light distribution lens to leave the light source, take a point on the incident light corresponding to the initial illuminated point as the starting feature point of the lens entrance surface, At a starting feature point on the light incident surface, a line parallel to the line connecting the LED light source and the initial illuminated point forms an angle with the incident light, which is the initial light deflection angle of the secondary light distribution lens. The initial ray deflection angle is divided into a first deflection angle and a second deflection angle. The angular division of the first deflection angle and the second deflection angle is used as a refracting line of the incident ray passing through the lens entrance surface, and the refraction law and the corresponding a small angle of the N small angles is obtained, and a second feature point on the light incident surface adjacent to the initial feature point on the light incident surface is obtained, and the second feature point on the light incident surface corresponds to the initial illumination Pointing adjacent second illuminated points;

Step 6.2: Perform step 6.1 for each of the N small segments, and sequentially determine the positions of the feature points on the light incident surface of the lens corresponding to each of the N small segments;

Step 6.3: taking a point on the refracting line after passing the initial feature point on the light incident surface of the lens, according to the lens thickness requirement of the secondary light distribution lens, as the lens exit surface of the full-circumferential light distribution lens At the starting feature point, the position of each feature point on the light exit surface of the lens is obtained as follows:

Step i1: at a starting feature point on the light-emitting surface, a line parallel to the line connecting the LED light source and the initial illuminated point forms an angle with the incident light, which is a starting light deflection angle of the secondary light distribution lens, The initial ray deflection angle is divided into a first deflection angle and a second deflection angle, and the angular division of the first deflection angle and the second deflection angle is used as a refracting line of the incident ray passing through the illuminating surface of the lens, and the law of refraction is Corresponding to one of the N small angles, determining a second feature point on the light exit surface adjacent to the starting feature point on the light exiting surface, the second feature point on the light exiting surface corresponding to the initial illuminated point Adjacent second illuminated point;

Step i2: performing step i1 for each of the N small segments, and sequentially determining the positions of the feature points on the lens light-emitting surface corresponding to each of the N small segments;

Step 6.4: sequentially connecting the feature points on the light incident surface of the lens, and sequentially connecting the feature points on the light exiting surface of the lens to form two continuous curves.
A method for designing a full-circumferential light distribution lens according to claim 1, wherein each of the feature points is sequentially connected by a straight line or a smooth curve.
The method for designing a full-circumferential light distribution lens according to claim 1, wherein the number of LED loops is two, and the light distribution curve formed by the secondary light distribution lens is divided into two parts, wherein The light distribution angle of a part of the light distribution curve is less than 180 degrees, and the light distribution angle of the other part of the light distribution curve is greater than or equal to 180 degrees.
A full-perimeter light distribution lens obtained by the design method of the full-perimeter light distribution lens according to any one of claims 1 to 3.
The full-perimeter light distribution lens according to claim 4, wherein the entire peripheral light distribution lens has a through hole in the middle thereof.